/*
 * Stream co-processor driver for the ETRAX FS
 *
 *    Copyright (C) 2003-2007  Axis Communications AB
 */

#include <linux/init.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>

#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/atomic.h>

#include <linux/list.h>
#include <linux/interrupt.h>

#include <asm/signal.h>
#include <asm/irq.h>

#include <dma.h>
#include <hwregs/dma.h>
#include <hwregs/reg_map.h>
#include <hwregs/reg_rdwr.h>
#include <hwregs/intr_vect_defs.h>

#include <hwregs/strcop.h>
#include <hwregs/strcop_defs.h>
#include <cryptocop.h>

#ifdef CONFIG_ETRAXFS
#define IN_DMA 9
#define OUT_DMA 8
#define IN_DMA_INST regi_dma9
#define OUT_DMA_INST regi_dma8
#define DMA_IRQ DMA9_INTR_VECT
#else
#define IN_DMA 3
#define OUT_DMA 2
#define IN_DMA_INST regi_dma3
#define OUT_DMA_INST regi_dma2
#define DMA_IRQ DMA3_INTR_VECT
#endif

#define DESCR_ALLOC_PAD  (31)

struct cryptocop_dma_desc {
        char *free_buf; /* If non-null will be kfreed in free_cdesc() */
        dma_descr_data *dma_descr;

        unsigned char dma_descr_buf[sizeof(dma_descr_data) + DESCR_ALLOC_PAD];

        unsigned int from_pool:1; /* If 1 'allocated' from the descriptor pool. */
        struct cryptocop_dma_desc *next;
};


struct cryptocop_int_operation{
        void                        *alloc_ptr;
        cryptocop_session_id        sid;

        dma_descr_context           ctx_out;
        dma_descr_context           ctx_in;

        /* DMA descriptors allocated by driver. */
        struct cryptocop_dma_desc   *cdesc_out;
        struct cryptocop_dma_desc   *cdesc_in;

        /* Strcop config to use. */
        cryptocop_3des_mode         tdes_mode;
        cryptocop_csum_type         csum_mode;

        /* DMA descrs provided by consumer. */
        dma_descr_data              *ddesc_out;
        dma_descr_data              *ddesc_in;
};


struct cryptocop_tfrm_ctx {
        cryptocop_tfrm_id tid;
        unsigned int blocklength;

        unsigned int start_ix;

        struct cryptocop_tfrm_cfg *tcfg;
        struct cryptocop_transform_ctx *tctx;

        unsigned char previous_src;
        unsigned char current_src;

        /* Values to use in metadata out. */
        unsigned char hash_conf;
        unsigned char hash_mode;
        unsigned char ciph_conf;
        unsigned char cbcmode;
        unsigned char decrypt;

        unsigned int requires_padding:1;
        unsigned int strict_block_length:1;
        unsigned int active:1;
        unsigned int done:1;
        size_t consumed;
        size_t produced;

        /* Pad (input) descriptors to put in the DMA out list when the transform
         * output is put on the DMA in list. */
        struct cryptocop_dma_desc *pad_descs;

        struct cryptocop_tfrm_ctx *prev_src;
        struct cryptocop_tfrm_ctx *curr_src;

        /* Mapping to HW. */
        unsigned char unit_no;
};


struct cryptocop_private{
        cryptocop_session_id sid;
        struct cryptocop_private *next;
};

/* Session list. */

struct cryptocop_transform_ctx{
        struct cryptocop_transform_init init;
        unsigned char dec_key[CRYPTOCOP_MAX_KEY_LENGTH];
        unsigned int dec_key_set:1;

        struct cryptocop_transform_ctx *next;
};


struct cryptocop_session{
        cryptocop_session_id sid;

        struct cryptocop_transform_ctx *tfrm_ctx;

        struct cryptocop_session *next;
};

/* Priority levels for jobs sent to the cryptocop.  Checksum operations from
   kernel have highest priority since TCPIP stack processing must not
   be a bottleneck. */
typedef enum {
        cryptocop_prio_kernel_csum = 0,
        cryptocop_prio_kernel = 1,
        cryptocop_prio_user = 2,
        cryptocop_prio_no_prios = 3
} cryptocop_queue_priority;

struct cryptocop_prio_queue{
        struct list_head jobs;
        cryptocop_queue_priority prio;
};

struct cryptocop_prio_job{
        struct list_head node;
        cryptocop_queue_priority prio;

        struct cryptocop_operation *oper;
        struct cryptocop_int_operation *iop;
};

struct ioctl_job_cb_ctx {
        unsigned int processed:1;
};


static struct cryptocop_session *cryptocop_sessions = NULL;
spinlock_t cryptocop_sessions_lock;

/* Next Session ID to assign. */
static cryptocop_session_id next_sid = 1;

/* Pad for checksum. */
static const char csum_zero_pad[1] = {0x00};

/* Trash buffer for mem2mem operations. */
#define MEM2MEM_DISCARD_BUF_LENGTH  (512)
static unsigned char mem2mem_discard_buf[MEM2MEM_DISCARD_BUF_LENGTH];

/* Descriptor pool. */
/* FIXME Tweak this value. */
#define CRYPTOCOP_DESCRIPTOR_POOL_SIZE   (100)
static struct cryptocop_dma_desc descr_pool[CRYPTOCOP_DESCRIPTOR_POOL_SIZE];
static struct cryptocop_dma_desc *descr_pool_free_list;
static int descr_pool_no_free;
static spinlock_t descr_pool_lock;

/* Lock to stop cryptocop to start processing of a new operation. The holder
   of this lock MUST call cryptocop_start_job() after it is unlocked. */
spinlock_t cryptocop_process_lock;

static struct cryptocop_prio_queue cryptocop_job_queues[cryptocop_prio_no_prios];
static spinlock_t cryptocop_job_queue_lock;
static struct cryptocop_prio_job *cryptocop_running_job = NULL;
static spinlock_t running_job_lock;

/* The interrupt handler appends completed jobs to this list. The scehduled
 * tasklet removes them upon sending the response to the crypto consumer. */
static struct list_head cryptocop_completed_jobs;
static spinlock_t cryptocop_completed_jobs_lock;

DECLARE_WAIT_QUEUE_HEAD(cryptocop_ioc_process_wq);


/** Local functions. **/

static int cryptocop_open(struct inode *, struct file *);

static int cryptocop_release(struct inode *, struct file *);

static long cryptocop_ioctl(struct file *file,
                           unsigned int cmd, unsigned long arg);

static void cryptocop_start_job(void);

static int cryptocop_job_queue_insert(cryptocop_queue_priority prio, struct cryptocop_operation *operation);
static int cryptocop_job_setup(struct cryptocop_prio_job **pj, struct cryptocop_operation *operation);

static int cryptocop_job_queue_init(void);
static void cryptocop_job_queue_close(void);

static int create_md5_pad(int alloc_flag, unsigned long long hashed_length, char **pad, size_t *pad_length);

static int create_sha1_pad(int alloc_flag, unsigned long long hashed_length, char **pad, size_t *pad_length);

static int transform_ok(struct cryptocop_transform_init *tinit);

static struct cryptocop_session *get_session(cryptocop_session_id sid);

static struct cryptocop_transform_ctx *get_transform_ctx(struct cryptocop_session *sess, cryptocop_tfrm_id tid);

static void delete_internal_operation(struct cryptocop_int_operation *iop);

static void get_aes_decrypt_key(unsigned char *dec_key, const unsigned  char *key, unsigned int keylength);

static int init_stream_coprocessor(void);

static void __exit exit_stream_coprocessor(void);

/*#define LDEBUG*/
#ifdef LDEBUG
#define DEBUG(s) s
#define DEBUG_API(s) s
static void print_cryptocop_operation(struct cryptocop_operation *cop);
static void print_dma_descriptors(struct cryptocop_int_operation *iop);
static void print_strcop_crypto_op(struct strcop_crypto_op *cop);
static void print_lock_status(void);
static void print_user_dma_lists(struct cryptocop_dma_list_operation *dma_op);
#define assert(s) do{if (!(s)) panic(#s);} while(0);
#else
#define DEBUG(s)
#define DEBUG_API(s)
#define assert(s)
#endif


/* Transform constants. */
#define DES_BLOCK_LENGTH   (8)
#define AES_BLOCK_LENGTH   (16)
#define MD5_BLOCK_LENGTH   (64)
#define SHA1_BLOCK_LENGTH  (64)
#define CSUM_BLOCK_LENGTH  (2)
#define MD5_STATE_LENGTH   (16)
#define SHA1_STATE_LENGTH  (20)

/* The device number. */
#define CRYPTOCOP_MAJOR    (254)
#define CRYPTOCOP_MINOR    (0)



const struct file_operations cryptocop_fops = {
        .owner          = THIS_MODULE,
        .open           = cryptocop_open,
        .release        = cryptocop_release,
        .unlocked_ioctl = cryptocop_ioctl,
        .llseek         = noop_llseek,
};


static void free_cdesc(struct cryptocop_dma_desc *cdesc)
{
        DEBUG(printk("free_cdesc: cdesc 0x%p, from_pool=%d\n", cdesc, cdesc->from_pool));
        kfree(cdesc->free_buf);

        if (cdesc->from_pool) {
                unsigned long int flags;
                spin_lock_irqsave(&descr_pool_lock, flags);
                cdesc->next = descr_pool_free_list;
                descr_pool_free_list = cdesc;
                ++descr_pool_no_free;
                spin_unlock_irqrestore(&descr_pool_lock, flags);
        } else {
                kfree(cdesc);
        }
}


static struct cryptocop_dma_desc *alloc_cdesc(int alloc_flag)
{
        int use_pool = (alloc_flag & GFP_ATOMIC) ? 1 : 0;
        struct cryptocop_dma_desc *cdesc;

        if (use_pool) {
                unsigned long int flags;
                spin_lock_irqsave(&descr_pool_lock, flags);
                if (!descr_pool_free_list) {
                        spin_unlock_irqrestore(&descr_pool_lock, flags);
                        DEBUG_API(printk("alloc_cdesc: pool is empty\n"));
                        return NULL;
                }
                cdesc = descr_pool_free_list;
                descr_pool_free_list = descr_pool_free_list->next;
                --descr_pool_no_free;
                spin_unlock_irqrestore(&descr_pool_lock, flags);
                cdesc->from_pool = 1;
        } else {
                cdesc = kmalloc(sizeof(struct cryptocop_dma_desc), alloc_flag);
                if (!cdesc) {
                        DEBUG_API(printk("alloc_cdesc: kmalloc\n"));
                        return NULL;
                }
                cdesc->from_pool = 0;
        }
        cdesc->dma_descr = (dma_descr_data*)(((unsigned long int)cdesc + offsetof(struct cryptocop_dma_desc, dma_descr_buf) + DESCR_ALLOC_PAD) & ~0x0000001F);

        cdesc->next = NULL;

        cdesc->free_buf = NULL;
        cdesc->dma_descr->out_eop = 0;
        cdesc->dma_descr->in_eop = 0;
        cdesc->dma_descr->intr = 0;
        cdesc->dma_descr->eol = 0;
        cdesc->dma_descr->wait = 0;
        cdesc->dma_descr->buf = NULL;
        cdesc->dma_descr->after = NULL;

        DEBUG_API(printk("alloc_cdesc: return 0x%p, cdesc->dma_descr=0x%p, from_pool=%d\n", cdesc, cdesc->dma_descr, cdesc->from_pool));
        return cdesc;
}


static void setup_descr_chain(struct cryptocop_dma_desc *cd)
{
        DEBUG(printk("setup_descr_chain: entering\n"));
        while (cd) {
                if (cd->next) {
                        cd->dma_descr->next = (dma_descr_data*)virt_to_phys(cd->next->dma_descr);
                } else {
                        cd->dma_descr->next = NULL;
                }
                cd = cd->next;
        }
        DEBUG(printk("setup_descr_chain: exit\n"));
}


/* Create a pad descriptor for the transform.
 * Return -1 for error, 0 if pad created. */
static int create_pad_descriptor(struct cryptocop_tfrm_ctx *tc, struct cryptocop_dma_desc **pad_desc, int alloc_flag)
{
        struct cryptocop_dma_desc        *cdesc = NULL;
        int                              error = 0;
        struct strcop_meta_out           mo = {
                .ciphsel = src_none,
                .hashsel = src_none,
                .csumsel = src_none
        };
        char                             *pad;
        size_t                           plen;

        DEBUG(printk("create_pad_descriptor: start.\n"));
        /* Setup pad descriptor. */

        DEBUG(printk("create_pad_descriptor: setting up padding.\n"));
        cdesc = alloc_cdesc(alloc_flag);
        if (!cdesc){
                DEBUG_API(printk("create_pad_descriptor: alloc pad desc\n"));
                goto error_cleanup;
        }
        switch (tc->unit_no) {
        case src_md5:
                error = create_md5_pad(alloc_flag, tc->consumed, &pad, &plen);
                if (error){
                        DEBUG_API(printk("create_pad_descriptor: create_md5_pad_failed\n"));
                        goto error_cleanup;
                }
                cdesc->free_buf = pad;
                mo.hashsel = src_dma;
                mo.hashconf = tc->hash_conf;
                mo.hashmode = tc->hash_mode;
                break;
        case src_sha1:
                error = create_sha1_pad(alloc_flag, tc->consumed, &pad, &plen);
                if (error){
                        DEBUG_API(printk("create_pad_descriptor: create_sha1_pad_failed\n"));
                        goto error_cleanup;
                }
                cdesc->free_buf = pad;
                mo.hashsel = src_dma;
                mo.hashconf = tc->hash_conf;
                mo.hashmode = tc->hash_mode;
                break;
        case src_csum:
                if (tc->consumed % tc->blocklength){
                        pad = (char*)csum_zero_pad;
                        plen = 1;
                } else {
                        pad = (char*)cdesc; /* Use any pointer. */
                        plen = 0;
                }
                mo.csumsel = src_dma;
                break;
        }
        cdesc->dma_descr->wait = 1;
        cdesc->dma_descr->out_eop = 1; /* Since this is a pad output is pushed.  EOP is ok here since the padded unit is the only one active. */
        cdesc->dma_descr->buf = (char*)virt_to_phys((char*)pad);
        cdesc->dma_descr->after = cdesc->dma_descr->buf + plen;

        cdesc->dma_descr->md = REG_TYPE_CONV(unsigned short int, struct strcop_meta_out, mo);
        *pad_desc = cdesc;

        return 0;

 error_cleanup:
        if (cdesc) free_cdesc(cdesc);
        return -1;
}


static int setup_key_dl_desc(struct cryptocop_tfrm_ctx *tc, struct cryptocop_dma_desc **kd, int alloc_flag)
{
        struct cryptocop_dma_desc  *key_desc = alloc_cdesc(alloc_flag);
        struct strcop_meta_out     mo = {0};

        DEBUG(printk("setup_key_dl_desc\n"));

        if (!key_desc) {
                DEBUG_API(printk("setup_key_dl_desc: failed descriptor allocation.\n"));
                return -ENOMEM;
        }

        /* Download key. */
        if ((tc->tctx->init.alg == cryptocop_alg_aes) && (tc->tcfg->flags & CRYPTOCOP_DECRYPT)) {
                /* Precook the AES decrypt key. */
                if (!tc->tctx->dec_key_set){
                        get_aes_decrypt_key(tc->tctx->dec_key, tc->tctx->init.key, tc->tctx->init.keylen);
                        tc->tctx->dec_key_set = 1;
                }
                key_desc->dma_descr->buf = (char*)virt_to_phys(tc->tctx->dec_key);
                key_desc->dma_descr->after = key_desc->dma_descr->buf + tc->tctx->init.keylen/8;
        } else {
                key_desc->dma_descr->buf = (char*)virt_to_phys(tc->tctx->init.key);
                key_desc->dma_descr->after = key_desc->dma_descr->buf + tc->tctx->init.keylen/8;
        }
        /* Setup metadata. */
        mo.dlkey = 1;
        switch (tc->tctx->init.keylen) {
        case 64:
                mo.decrypt = 0;
                mo.hashmode = 0;
                break;
        case 128:
                mo.decrypt = 0;
                mo.hashmode = 1;
                break;
        case 192:
                mo.decrypt = 1;
                mo.hashmode = 0;
                break;
        case 256:
                mo.decrypt = 1;
                mo.hashmode = 1;
                break;
        default:
                break;
        }
        mo.ciphsel = mo.hashsel = mo.csumsel = src_none;
        key_desc->dma_descr->md = REG_TYPE_CONV(unsigned short int, struct strcop_meta_out, mo);

        key_desc->dma_descr->out_eop = 1;
        key_desc->dma_descr->wait = 1;
        key_desc->dma_descr->intr = 0;

        *kd = key_desc;
        return 0;
}

static int setup_cipher_iv_desc(struct cryptocop_tfrm_ctx *tc, struct cryptocop_dma_desc **id, int alloc_flag)
{
        struct cryptocop_dma_desc  *iv_desc = alloc_cdesc(alloc_flag);
        struct strcop_meta_out     mo = {0};

        DEBUG(printk("setup_cipher_iv_desc\n"));

        if (!iv_desc) {
                DEBUG_API(printk("setup_cipher_iv_desc: failed CBC IV descriptor allocation.\n"));
                return -ENOMEM;
        }
        /* Download IV. */
        iv_desc->dma_descr->buf = (char*)virt_to_phys(tc->tcfg->iv);
        iv_desc->dma_descr->after = iv_desc->dma_descr->buf + tc->blocklength;

        /* Setup metadata. */
        mo.hashsel = mo.csumsel = src_none;
        mo.ciphsel = src_dma;
        mo.ciphconf = tc->ciph_conf;
        mo.cbcmode = tc->cbcmode;

        iv_desc->dma_descr->md = REG_TYPE_CONV(unsigned short int, struct strcop_meta_out, mo);

        iv_desc->dma_descr->out_eop = 0;
        iv_desc->dma_descr->wait = 1;
        iv_desc->dma_descr->intr = 0;

        *id = iv_desc;
        return 0;
}

/* Map the ouput length of the transform to operation output starting on the inject index. */
static int create_input_descriptors(struct cryptocop_operation *operation, struct cryptocop_tfrm_ctx *tc, struct cryptocop_dma_desc **id, int alloc_flag)
{
        int                        err = 0;
        struct cryptocop_dma_desc  head = {0};
        struct cryptocop_dma_desc  *outdesc = &head;
        size_t                     iov_offset = 0;
        size_t                     out_ix = 0;
        int                        outiov_ix = 0;
        struct strcop_meta_in      mi = {0};

        size_t                     out_length = tc->produced;
        int                        rem_length;
        int                        dlength;

        assert(out_length != 0);
        if (((tc->produced + tc->tcfg->inject_ix) > operation->tfrm_op.outlen) || (tc->produced && (operation->tfrm_op.outlen == 0))) {
                DEBUG_API(printk("create_input_descriptors: operation outdata too small\n"));
                return -EINVAL;
        }
        /* Traverse the out iovec until the result inject index is reached. */
        while ((outiov_ix < operation->tfrm_op.outcount) && ((out_ix + operation->tfrm_op.outdata[outiov_ix].iov_len) <= tc->tcfg->inject_ix)){
                out_ix += operation->tfrm_op.outdata[outiov_ix].iov_len;
                outiov_ix++;
        }
        if (outiov_ix >= operation->tfrm_op.outcount){
                DEBUG_API(printk("create_input_descriptors: operation outdata too small\n"));
                return -EINVAL;
        }
        iov_offset = tc->tcfg->inject_ix - out_ix;
        mi.dmasel = tc->unit_no;

        /* Setup the output descriptors. */
        while ((out_length > 0) && (outiov_ix < operation->tfrm_op.outcount)) {
                outdesc->next = alloc_cdesc(alloc_flag);
                if (!outdesc->next) {
                        DEBUG_API(printk("create_input_descriptors: alloc_cdesc\n"));
                        err = -ENOMEM;
                        goto error_cleanup;
                }
                outdesc = outdesc->next;
                rem_length = operation->tfrm_op.outdata[outiov_ix].iov_len - iov_offset;
                dlength = (out_length < rem_length) ? out_length : rem_length;

                DEBUG(printk("create_input_descriptors:\n"
                             "outiov_ix=%d, rem_length=%d, dlength=%d\n"
                             "iov_offset=%d, outdata[outiov_ix].iov_len=%d\n"
                             "outcount=%d, outiov_ix=%d\n",
                             outiov_ix, rem_length, dlength, iov_offset, operation->tfrm_op.outdata[outiov_ix].iov_len, operation->tfrm_op.outcount, outiov_ix));

                outdesc->dma_descr->buf = (char*)virt_to_phys(operation->tfrm_op.outdata[outiov_ix].iov_base + iov_offset);
                outdesc->dma_descr->after = outdesc->dma_descr->buf + dlength;
                outdesc->dma_descr->md = REG_TYPE_CONV(unsigned short int, struct strcop_meta_in, mi);

                out_length -= dlength;
                iov_offset += dlength;
                if (iov_offset >= operation->tfrm_op.outdata[outiov_ix].iov_len) {
                        iov_offset = 0;
                        ++outiov_ix;
                }
        }
        if (out_length > 0){
                DEBUG_API(printk("create_input_descriptors: not enough room for output, %d remained\n", out_length));
                err = -EINVAL;
                goto error_cleanup;
        }
        /* Set sync in last descriptor. */
        mi.sync = 1;
        outdesc->dma_descr->md = REG_TYPE_CONV(unsigned short int, struct strcop_meta_in, mi);

        *id = head.next;
        return 0;

 error_cleanup:
        while (head.next) {
                outdesc = head.next->next;
                free_cdesc(head.next);
                head.next = outdesc;
        }
        return err;
}


static int create_output_descriptors(struct cryptocop_operation *operation, int *iniov_ix, int *iniov_offset, size_t desc_len, struct cryptocop_dma_desc **current_out_cdesc, struct strcop_meta_out *meta_out, int alloc_flag)
{
        while (desc_len != 0) {
                struct cryptocop_dma_desc  *cdesc;
                int                        rem_length = operation->tfrm_op.indata[*iniov_ix].iov_len - *iniov_offset;
                int                        dlength = (desc_len < rem_length) ? desc_len : rem_length;

                cdesc = alloc_cdesc(alloc_flag);
                if (!cdesc) {
                        DEBUG_API(printk("create_output_descriptors: alloc_cdesc\n"));
                        return -ENOMEM;
                }
                (*current_out_cdesc)->next = cdesc;
                (*current_out_cdesc) = cdesc;

                cdesc->free_buf = NULL;

                cdesc->dma_descr->buf = (char*)virt_to_phys(operation->tfrm_op.indata[*iniov_ix].iov_base + *iniov_offset);
                cdesc->dma_descr->after = cdesc->dma_descr->buf + dlength;

                assert(desc_len >= dlength);
                desc_len -= dlength;
                *iniov_offset += dlength;
                if (*iniov_offset >= operation->tfrm_op.indata[*iniov_ix].iov_len) {
                        *iniov_offset = 0;
                        ++(*iniov_ix);
                        if (*iniov_ix > operation->tfrm_op.incount) {
                                DEBUG_API(printk("create_output_descriptors: not enough indata in operation."));
                                return  -EINVAL;
                        }
                }
                cdesc->dma_descr->md = REG_TYPE_CONV(unsigned short int, struct strcop_meta_out, (*meta_out));
        } /* while (desc_len != 0) */
        /* Last DMA descriptor gets a 'wait' bit to signal expected change in metadata. */
        (*current_out_cdesc)->dma_descr->wait = 1; /* This will set extraneous WAIT in some situations, e.g. when padding hashes and checksums. */

        return 0;
}


static int append_input_descriptors(struct cryptocop_operation *operation, struct cryptocop_dma_desc **current_in_cdesc, struct cryptocop_dma_desc **current_out_cdesc, struct cryptocop_tfrm_ctx *tc, int alloc_flag)
{
        DEBUG(printk("append_input_descriptors, tc=0x%p, unit_no=%d\n", tc, tc->unit_no));
        if (tc->tcfg) {
                int                        failed = 0;
                struct cryptocop_dma_desc  *idescs = NULL;
                DEBUG(printk("append_input_descriptors: pushing output, consumed %d produced %d bytes.\n", tc->consumed, tc->produced));
                if (tc->pad_descs) {
                        DEBUG(printk("append_input_descriptors: append pad descriptors to DMA out list.\n"));
                        while (tc->pad_descs) {
                                DEBUG(printk("append descriptor 0x%p\n", tc->pad_descs));
                                (*current_out_cdesc)->next = tc->pad_descs;
                                tc->pad_descs = tc->pad_descs->next;
                                (*current_out_cdesc) = (*current_out_cdesc)->next;
                        }
                }

                /* Setup and append output descriptors to DMA in list. */
                if (tc->unit_no == src_dma){
                        /* mem2mem.  Setup DMA in descriptors to discard all input prior to the requested mem2mem data. */
                        struct strcop_meta_in mi = {.sync = 0, .dmasel = src_dma};
                        unsigned int start_ix = tc->start_ix;
                        while (start_ix){
                                unsigned int desclen = start_ix < MEM2MEM_DISCARD_BUF_LENGTH ? start_ix : MEM2MEM_DISCARD_BUF_LENGTH;
                                (*current_in_cdesc)->next = alloc_cdesc(alloc_flag);
                                if (!(*current_in_cdesc)->next){
                                        DEBUG_API(printk("append_input_descriptors: alloc_cdesc mem2mem discard failed\n"));
                                        return -ENOMEM;
                                }
                                (*current_in_cdesc) = (*current_in_cdesc)->next;
                                (*current_in_cdesc)->dma_descr->buf = (char*)virt_to_phys(mem2mem_discard_buf);
                                (*current_in_cdesc)->dma_descr->after = (*current_in_cdesc)->dma_descr->buf + desclen;
                                (*current_in_cdesc)->dma_descr->md = REG_TYPE_CONV(unsigned short int, struct strcop_meta_in, mi);
                                start_ix -= desclen;
                        }
                        mi.sync = 1;
                        (*current_in_cdesc)->dma_descr->md = REG_TYPE_CONV(unsigned short int, struct strcop_meta_in, mi);
                }

                failed = create_input_descriptors(operation, tc, &idescs, alloc_flag);
                if (failed){
                        DEBUG_API(printk("append_input_descriptors: output descriptor setup failed\n"));
                        return failed;
                }
                DEBUG(printk("append_input_descriptors: append output descriptors to DMA in list.\n"));
                while (idescs) {
                        DEBUG(printk("append descriptor 0x%p\n", idescs));
                        (*current_in_cdesc)->next = idescs;
                        idescs = idescs->next;
                        (*current_in_cdesc) = (*current_in_cdesc)->next;
                }
        }
        return 0;
}



static int cryptocop_setup_dma_list(struct cryptocop_operation *operation, struct cryptocop_int_operation **int_op, int alloc_flag)
{
        struct cryptocop_session *sess;
        struct cryptocop_transform_ctx *tctx;

        struct cryptocop_tfrm_ctx digest_ctx = {
                .previous_src = src_none,
                .current_src = src_none,
                .start_ix = 0,
                .requires_padding = 1,
                .strict_block_length = 0,
                .hash_conf = 0,
                .hash_mode = 0,
                .ciph_conf = 0,
                .cbcmode = 0,
                .decrypt = 0,
                .consumed = 0,
                .produced = 0,
                .pad_descs = NULL,
                .active = 0,
                .done = 0,
                .prev_src = NULL,
                .curr_src = NULL,
                .tcfg = NULL};
        struct cryptocop_tfrm_ctx cipher_ctx = {
                .previous_src = src_none,
                .current_src = src_none,
                .start_ix = 0,
                .requires_padding = 0,
                .strict_block_length = 1,
                .hash_conf = 0,
                .hash_mode = 0,
                .ciph_conf = 0,
                .cbcmode = 0,
                .decrypt = 0,
                .consumed = 0,
                .produced = 0,
                .pad_descs = NULL,
                .active = 0,
                .done = 0,
                .prev_src = NULL,
                .curr_src = NULL,
                .tcfg = NULL};
        struct cryptocop_tfrm_ctx csum_ctx = {
                .previous_src = src_none,
                .current_src = src_none,
                .start_ix = 0,
                .blocklength = 2,
                .requires_padding = 1,
                .strict_block_length = 0,
                .hash_conf = 0,
                .hash_mode = 0,
                .ciph_conf = 0,
                .cbcmode = 0,
                .decrypt = 0,
                .consumed = 0,
                .produced = 0,
                .pad_descs = NULL,
                .active = 0,
                .done = 0,
                .tcfg = NULL,
                .prev_src = NULL,
                .curr_src = NULL,
                .unit_no = src_csum};
        struct cryptocop_tfrm_cfg *tcfg = operation->tfrm_op.tfrm_cfg;

        unsigned int indata_ix = 0;

        /* iovec accounting. */
        int iniov_ix = 0;
        int iniov_offset = 0;

        /* Operation descriptor cfg traversal pointer. */
        struct cryptocop_desc *odsc;

        int failed = 0;
        /* List heads for allocated descriptors. */
        struct cryptocop_dma_desc out_cdesc_head = {0};
        struct cryptocop_dma_desc in_cdesc_head = {0};

        struct cryptocop_dma_desc *current_out_cdesc = &out_cdesc_head;
        struct cryptocop_dma_desc *current_in_cdesc = &in_cdesc_head;

        struct cryptocop_tfrm_ctx *output_tc = NULL;
        void                      *iop_alloc_ptr;

        assert(operation != NULL);
        assert(int_op != NULL);

        DEBUG(printk("cryptocop_setup_dma_list: start\n"));
        DEBUG(print_cryptocop_operation(operation));

        sess = get_session(operation->sid);
        if (!sess) {
                DEBUG_API(printk("cryptocop_setup_dma_list: no session found for operation.\n"));
                failed = -EINVAL;
                goto error_cleanup;
        }
        iop_alloc_ptr = kmalloc(DESCR_ALLOC_PAD + sizeof(struct cryptocop_int_operation), alloc_flag);
        if (!iop_alloc_ptr) {
                DEBUG_API(printk("cryptocop_setup_dma_list:  kmalloc cryptocop_int_operation\n"));
                failed = -ENOMEM;
                goto error_cleanup;
        }
        (*int_op) = (struct cryptocop_int_operation*)(((unsigned long int)(iop_alloc_ptr + DESCR_ALLOC_PAD + offsetof(struct cryptocop_int_operation, ctx_out)) & ~0x0000001F) - offsetof(struct cryptocop_int_operation, ctx_out));
        DEBUG(memset((*int_op), 0xff, sizeof(struct cryptocop_int_operation)));
        (*int_op)->alloc_ptr = iop_alloc_ptr;
        DEBUG(printk("cryptocop_setup_dma_list: *int_op=0x%p, alloc_ptr=0x%p\n", *int_op, (*int_op)->alloc_ptr));

        (*int_op)->sid = operation->sid;
        (*int_op)->cdesc_out = NULL;
        (*int_op)->cdesc_in = NULL;
        (*int_op)->tdes_mode = cryptocop_3des_ede;
        (*int_op)->csum_mode = cryptocop_csum_le;
        (*int_op)->ddesc_out = NULL;
        (*int_op)->ddesc_in = NULL;

        /* Scan operation->tfrm_op.tfrm_cfg for bad configuration and set up the local contexts. */
        if (!tcfg) {
                DEBUG_API(printk("cryptocop_setup_dma_list: no configured transforms in operation.\n"));
                failed = -EINVAL;
                goto error_cleanup;
        }
        while (tcfg) {
                tctx = get_transform_ctx(sess, tcfg->tid);
                if (!tctx) {
                        DEBUG_API(printk("cryptocop_setup_dma_list: no transform id %d in session.\n", tcfg->tid));
                        failed = -EINVAL;
                        goto error_cleanup;
                }
                if (tcfg->inject_ix > operation->tfrm_op.outlen){
                        DEBUG_API(printk("cryptocop_setup_dma_list: transform id %d inject_ix (%d) > operation->tfrm_op.outlen(%d)", tcfg->tid, tcfg->inject_ix, operation->tfrm_op.outlen));
                        failed = -EINVAL;
                        goto error_cleanup;
                }
                switch (tctx->init.alg){
                case cryptocop_alg_mem2mem:
                        if (cipher_ctx.tcfg != NULL){
                                DEBUG_API(printk("cryptocop_setup_dma_list: multiple ciphers in operation.\n"));
                                failed = -EINVAL;
                                goto error_cleanup;
                        }
                        /* mem2mem is handled as a NULL cipher. */
                        cipher_ctx.cbcmode = 0;
                        cipher_ctx.decrypt = 0;
                        cipher_ctx.blocklength = 1;
                        cipher_ctx.ciph_conf = 0;
                        cipher_ctx.unit_no = src_dma;
                        cipher_ctx.tcfg = tcfg;
                        cipher_ctx.tctx = tctx;
                        break;
                case cryptocop_alg_des:
                case cryptocop_alg_3des:
                case cryptocop_alg_aes:
                        /* cipher */
                        if (cipher_ctx.tcfg != NULL){
                                DEBUG_API(printk("cryptocop_setup_dma_list: multiple ciphers in operation.\n"));
                                failed = -EINVAL;
                                goto error_cleanup;
                        }
                        cipher_ctx.tcfg = tcfg;
                        cipher_ctx.tctx = tctx;
                        if (cipher_ctx.tcfg->flags & CRYPTOCOP_DECRYPT){
                                cipher_ctx.decrypt = 1;
                        }
                        switch (tctx->init.cipher_mode) {
                        case cryptocop_cipher_mode_ecb:
                                cipher_ctx.cbcmode = 0;
                                break;
                        case cryptocop_cipher_mode_cbc:
                                cipher_ctx.cbcmode = 1;
                                break;
                        default:
                                DEBUG_API(printk("cryptocop_setup_dma_list: cipher_ctx, bad cipher mode==%d\n", tctx->init.cipher_mode));
                                failed = -EINVAL;
                                goto error_cleanup;
                        }
                        DEBUG(printk("cryptocop_setup_dma_list: cipher_ctx, set CBC mode==%d\n", cipher_ctx.cbcmode));
                        switch (tctx->init.alg){
                        case cryptocop_alg_des:
                                cipher_ctx.ciph_conf = 0;
                                cipher_ctx.unit_no = src_des;
                                cipher_ctx.blocklength = DES_BLOCK_LENGTH;
                                break;
                        case cryptocop_alg_3des:
                                cipher_ctx.ciph_conf = 1;
                                cipher_ctx.unit_no = src_des;
                                cipher_ctx.blocklength = DES_BLOCK_LENGTH;
                                break;
                        case cryptocop_alg_aes:
                                cipher_ctx.ciph_conf = 2;
                                cipher_ctx.unit_no = src_aes;
                                cipher_ctx.blocklength = AES_BLOCK_LENGTH;
                                break;
                        default:
                                panic("cryptocop_setup_dma_list: impossible algorithm %d\n", tctx->init.alg);
                        }
                        (*int_op)->tdes_mode = tctx->init.tdes_mode;
                        break;
                case cryptocop_alg_md5:
                case cryptocop_alg_sha1:
                        /* digest */
                        if (digest_ctx.tcfg != NULL){
                                DEBUG_API(printk("cryptocop_setup_dma_list: multiple digests in operation.\n"));
                                failed = -EINVAL;
                                goto error_cleanup;
                        }
                        digest_ctx.tcfg = tcfg;
                        digest_ctx.tctx = tctx;
                        digest_ctx.hash_mode = 0; /* Don't use explicit IV in this API. */
                        switch (tctx->init.alg){
                        case cryptocop_alg_md5:
                                digest_ctx.blocklength = MD5_BLOCK_LENGTH;
                                digest_ctx.unit_no = src_md5;
                                digest_ctx.hash_conf = 1; /* 1 => MD-5 */
                                break;
                        case cryptocop_alg_sha1:
                                digest_ctx.blocklength = SHA1_BLOCK_LENGTH;
                                digest_ctx.unit_no = src_sha1;
                                digest_ctx.hash_conf = 0; /* 0 => SHA-1 */
                                break;
                        default:
                                panic("cryptocop_setup_dma_list: impossible digest algorithm\n");
                        }
                        break;
                case cryptocop_alg_csum:
                        /* digest */
                        if (csum_ctx.tcfg != NULL){
                                DEBUG_API(printk("cryptocop_setup_dma_list: multiple checksums in operation.\n"));
                                failed = -EINVAL;
                                goto error_cleanup;
                        }
                        (*int_op)->csum_mode = tctx->init.csum_mode;
                        csum_ctx.tcfg = tcfg;
                        csum_ctx.tctx = tctx;
                        break;
                default:
                        /* no algorithm. */
                        DEBUG_API(printk("cryptocop_setup_dma_list: invalid algorithm %d specified in tfrm %d.\n", tctx->init.alg, tcfg->tid));
                        failed = -EINVAL;
                        goto error_cleanup;
                }
                tcfg = tcfg->next;
        }
        /* Download key if a cipher is used. */
        if (cipher_ctx.tcfg && (cipher_ctx.tctx->init.alg != cryptocop_alg_mem2mem)){
                struct cryptocop_dma_desc  *key_desc = NULL;

                failed = setup_key_dl_desc(&cipher_ctx, &key_desc, alloc_flag);
                if (failed) {
                        DEBUG_API(printk("cryptocop_setup_dma_list: setup key dl\n"));
                        goto error_cleanup;
                }
                current_out_cdesc->next = key_desc;
                current_out_cdesc = key_desc;
                indata_ix += (unsigned int)(key_desc->dma_descr->after - key_desc->dma_descr->buf);

                /* Download explicit IV if a cipher is used and CBC mode and explicit IV selected. */
                if ((cipher_ctx.tctx->init.cipher_mode == cryptocop_cipher_mode_cbc) && (cipher_ctx.tcfg->flags & CRYPTOCOP_EXPLICIT_IV)) {
                        struct cryptocop_dma_desc  *iv_desc = NULL;

                        DEBUG(printk("cryptocop_setup_dma_list: setup cipher CBC IV descriptor.\n"));

                        failed = setup_cipher_iv_desc(&cipher_ctx, &iv_desc, alloc_flag);
                        if (failed) {
                                DEBUG_API(printk("cryptocop_setup_dma_list: CBC IV descriptor.\n"));
                                goto error_cleanup;
                        }
                        current_out_cdesc->next = iv_desc;
                        current_out_cdesc = iv_desc;
                        indata_ix += (unsigned int)(iv_desc->dma_descr->after - iv_desc->dma_descr->buf);
                }
        }

        /* Process descriptors. */
        odsc = operation->tfrm_op.desc;
        while (odsc) {
                struct cryptocop_desc_cfg   *dcfg = odsc->cfg;
                struct strcop_meta_out      meta_out = {0};
                size_t                      desc_len = odsc->length;
                int                         active_count, eop_needed_count;

                output_tc = NULL;

                DEBUG(printk("cryptocop_setup_dma_list: parsing an operation descriptor\n"));

                while (dcfg) {
                        struct cryptocop_tfrm_ctx  *tc = NULL;

                        DEBUG(printk("cryptocop_setup_dma_list: parsing an operation descriptor configuration.\n"));
                        /* Get the local context for the transform and mark it as the output unit if it produces output. */
                        if (digest_ctx.tcfg && (digest_ctx.tcfg->tid == dcfg->tid)){
                                tc = &digest_ctx;

                        } else if (cipher_ctx.tcfg && (cipher_ctx.tcfg->tid == dcfg->tid)){
                                tc = &cipher_ctx;
                        } else if (csum_ctx.tcfg && (csum_ctx.tcfg->tid == dcfg->tid)){
                                tc = &csum_ctx;
                        }
                        if (!tc) {
                                DEBUG_API(printk("cryptocop_setup_dma_list: invalid transform %d specified in descriptor.\n", dcfg->tid));
                                failed = -EINVAL;
                                goto error_cleanup;
                        }
                        if (tc->done) {
                                DEBUG_API(printk("cryptocop_setup_dma_list: completed transform %d reused.\n", dcfg->tid));
                                failed = -EINVAL;
                                goto error_cleanup;
                        }
                        if (!tc->active) {
                                tc->start_ix = indata_ix;
                                tc->active = 1;
                        }

                        tc->previous_src = tc->current_src;
                        tc->prev_src = tc->curr_src;
                        /* Map source unit id to DMA source config. */
                        switch (dcfg->src){
                        case cryptocop_source_dma:
                                tc->current_src = src_dma;
                                break;
                        case cryptocop_source_des:
                                tc->current_src = src_des;
                                break;
                        case cryptocop_source_3des:
                                tc->current_src = src_des;
                                break;
                        case cryptocop_source_aes:
                                tc->current_src = src_aes;
                                break;
                        case cryptocop_source_md5:
                        case cryptocop_source_sha1:
                        case cryptocop_source_csum:
                        case cryptocop_source_none:
                        default:
                                /* We do not allow using accumulating style units (SHA-1, MD5, checksum) as sources to other units.
                                 */
                                DEBUG_API(printk("cryptocop_setup_dma_list: bad unit source configured %d.\n", dcfg->src));
                                failed = -EINVAL;
                                goto error_cleanup;
                        }
                        if (tc->current_src != src_dma) {
                                /* Find the unit we are sourcing from. */
                                if (digest_ctx.unit_no == tc->current_src){
                                        tc->curr_src = &digest_ctx;
                                } else if (cipher_ctx.unit_no == tc->current_src){
                                        tc->curr_src = &cipher_ctx;
                                } else if (csum_ctx.unit_no == tc->current_src){
                                        tc->curr_src = &csum_ctx;
                                }
                                if ((tc->curr_src == tc) && (tc->unit_no != src_dma)){
                                        DEBUG_API(printk("cryptocop_setup_dma_list: unit %d configured to source from itself.\n", tc->unit_no));
                                        failed = -EINVAL;
                                        goto error_cleanup;
                                }
                        } else {
                                tc->curr_src = NULL;
                        }

                        /* Detect source switch. */
                        DEBUG(printk("cryptocop_setup_dma_list: tc->active=%d tc->unit_no=%d tc->current_src=%d tc->previous_src=%d, tc->curr_src=0x%p, tc->prev_srv=0x%p\n", tc->active, tc->unit_no, tc->current_src, tc->previous_src, tc->curr_src, tc->prev_src));
                        if (tc->active && (tc->current_src != tc->previous_src)) {
                                /* Only allow source switch when both the old source unit and the new one have
                                 * no pending data to process (i.e. the consumed length must be a multiple of the
                                 * transform blocklength). */
                                /* Note: if the src == NULL we are actually sourcing from DMA out. */
                                if (((tc->prev_src != NULL) && (tc->prev_src->consumed % tc->prev_src->blocklength)) ||
                                    ((tc->curr_src != NULL) && (tc->curr_src->consumed % tc->curr_src->blocklength)))
                                {
                                        DEBUG_API(printk("cryptocop_setup_dma_list: can only disconnect from or connect to a unit on a multiple of the blocklength, old: cons=%d, prod=%d, block=%d, new: cons=%d prod=%d, block=%d.\n", tc->prev_src ? tc->prev_src->consumed : INT_MIN, tc->prev_src ? tc->prev_src->produced : INT_MIN, tc->prev_src ? tc->prev_src->blocklength : INT_MIN, tc->curr_src ? tc->curr_src->consumed : INT_MIN, tc->curr_src ? tc->curr_src->produced : INT_MIN, tc->curr_src ? tc->curr_src->blocklength : INT_MIN));
                                        failed = -EINVAL;
                                        goto error_cleanup;
                                }
                        }
                        /* Detect unit deactivation. */
                        if (dcfg->last) {
                                /* Length check of this is handled below. */
                                tc->done = 1;
                        }
                        dcfg = dcfg->next;
                } /* while (dcfg) */
                DEBUG(printk("cryptocop_setup_dma_list: parsing operation descriptor configuration complete.\n"));

                if (cipher_ctx.active && (cipher_ctx.curr_src != NULL) && !cipher_ctx.curr_src->active){
                        DEBUG_API(printk("cryptocop_setup_dma_list: cipher source from inactive unit %d\n", cipher_ctx.curr_src->unit_no));
                        failed = -EINVAL;
                        goto error_cleanup;
                }
                if (digest_ctx.active && (digest_ctx.curr_src != NULL) && !digest_ctx.curr_src->active){
                        DEBUG_API(printk("cryptocop_setup_dma_list: digest source from inactive unit %d\n", digest_ctx.curr_src->unit_no));
                        failed = -EINVAL;
                        goto error_cleanup;
                }
                if (csum_ctx.active && (csum_ctx.curr_src != NULL) && !csum_ctx.curr_src->active){
                        DEBUG_API(printk("cryptocop_setup_dma_list: cipher source from inactive unit %d\n", csum_ctx.curr_src->unit_no));
                        failed = -EINVAL;
                        goto error_cleanup;
                }

                /* Update consumed and produced lengths.

                   The consumed length accounting here is actually cheating.  If a unit source from DMA (or any
                   other unit that process data in blocks of one octet) it is correct, but if it source from a
                   block processing unit, i.e. a cipher, it will be temporarily incorrect at some times.  However
                   since it is only allowed--by the HW--to change source to or from a block processing unit at times where that
                   unit has processed an exact multiple of its block length the end result will be correct.
                   Beware that if the source change restriction change this code will need to be (much) reworked.
                */
                DEBUG(printk("cryptocop_setup_dma_list: desc->length=%d, desc_len=%d.\n", odsc->length, desc_len));

                if (csum_ctx.active) {
                        csum_ctx.consumed += desc_len;
                        if (csum_ctx.done) {
                                csum_ctx.produced = 2;
                        }
                        DEBUG(printk("cryptocop_setup_dma_list: csum_ctx producing: consumed=%d, produced=%d, blocklength=%d.\n", csum_ctx.consumed, csum_ctx.produced, csum_ctx.blocklength));
                }
                if (digest_ctx.active) {
                        digest_ctx.consumed += desc_len;
                        if (digest_ctx.done) {
                                if (digest_ctx.unit_no == src_md5) {
                                        digest_ctx.produced = MD5_STATE_LENGTH;
                                } else {
                                        digest_ctx.produced = SHA1_STATE_LENGTH;
                                }
                        }
                        DEBUG(printk("cryptocop_setup_dma_list: digest_ctx producing: consumed=%d, produced=%d, blocklength=%d.\n", digest_ctx.consumed, digest_ctx.produced, digest_ctx.blocklength));
                }
                if (cipher_ctx.active) {
                        /* Ciphers are allowed only to source from DMA out.  That is filtered above. */
                        assert(cipher_ctx.current_src == src_dma);
                        cipher_ctx.consumed += desc_len;
                        cipher_ctx.produced = cipher_ctx.blocklength * (cipher_ctx.consumed / cipher_ctx.blocklength);
                        if (cipher_ctx.cbcmode && !(cipher_ctx.tcfg->flags & CRYPTOCOP_EXPLICIT_IV) && cipher_ctx.produced){
                                cipher_ctx.produced -= cipher_ctx.blocklength; /* Compensate for CBC iv. */
                        }
                        DEBUG(printk("cryptocop_setup_dma_list: cipher_ctx producing: consumed=%d, produced=%d, blocklength=%d.\n", cipher_ctx.consumed, cipher_ctx.produced, cipher_ctx.blocklength));
                }

                /* Setup the DMA out descriptors. */
                /* Configure the metadata. */
                active_count = 0;
                eop_needed_count = 0;
                if (cipher_ctx.active) {
                        ++active_count;
                        if (cipher_ctx.unit_no == src_dma){
                                /* mem2mem */
                                meta_out.ciphsel = src_none;
                        } else {
                                meta_out.ciphsel = cipher_ctx.current_src;
                        }
                        meta_out.ciphconf = cipher_ctx.ciph_conf;
                        meta_out.cbcmode = cipher_ctx.cbcmode;
                        meta_out.decrypt = cipher_ctx.decrypt;
                        DEBUG(printk("set ciphsel=%d ciphconf=%d cbcmode=%d decrypt=%d\n", meta_out.ciphsel, meta_out.ciphconf, meta_out.cbcmode, meta_out.decrypt));
                        if (cipher_ctx.done) ++eop_needed_count;
                } else {
                        meta_out.ciphsel = src_none;
                }

                if (digest_ctx.active) {
                        ++active_count;
                        meta_out.hashsel = digest_ctx.current_src;
                        meta_out.hashconf = digest_ctx.hash_conf;
                        meta_out.hashmode = 0; /* Explicit mode is not used here. */
                        DEBUG(printk("set hashsel=%d hashconf=%d hashmode=%d\n", meta_out.hashsel, meta_out.hashconf, meta_out.hashmode));
                        if (digest_ctx.done) {
                                assert(digest_ctx.pad_descs == NULL);
                                failed = create_pad_descriptor(&digest_ctx, &digest_ctx.pad_descs, alloc_flag);
                                if (failed) {
                                        DEBUG_API(printk("cryptocop_setup_dma_list: failed digest pad creation.\n"));
                                        goto error_cleanup;
                                }
                        }
                } else {
                        meta_out.hashsel = src_none;
                }

                if (csum_ctx.active) {
                        ++active_count;
                        meta_out.csumsel = csum_ctx.current_src;
                        if (csum_ctx.done) {
                                assert(csum_ctx.pad_descs == NULL);
                                failed = create_pad_descriptor(&csum_ctx, &csum_ctx.pad_descs, alloc_flag);
                                if (failed) {
                                        DEBUG_API(printk("cryptocop_setup_dma_list: failed csum pad creation.\n"));
                                        goto error_cleanup;
                                }
                        }
                } else {
                        meta_out.csumsel = src_none;
                }
                DEBUG(printk("cryptocop_setup_dma_list: %d eop needed, %d active units\n", eop_needed_count, active_count));
                /* Setup DMA out descriptors for the indata. */
                failed = create_output_descriptors(operation, &iniov_ix, &iniov_offset, desc_len, &current_out_cdesc, &meta_out, alloc_flag);
                if (failed) {
                        DEBUG_API(printk("cryptocop_setup_dma_list: create_output_descriptors %d\n", failed));
                        goto error_cleanup;
                }
                /* Setup out EOP.  If there are active units that are not done here they cannot get an EOP
                 * so we ust setup a zero length descriptor to DMA to signal EOP only to done units.
                 * If there is a pad descriptor EOP for the padded unit will be EOPed by it.
                 */
                assert(active_count >= eop_needed_count);
                assert((eop_needed_count == 0) || (eop_needed_count == 1));
                if (eop_needed_count) {
                        /* This means that the bulk operation (cipeher/m2m) is terminated. */
                        if (active_count > 1) {
                                /* Use zero length EOP descriptor. */
                                struct cryptocop_dma_desc *ed = alloc_cdesc(alloc_flag);
                                struct strcop_meta_out    ed_mo = {0};
                                if (!ed) {
                                        DEBUG_API(printk("cryptocop_setup_dma_list: alloc EOP descriptor for cipher\n"));
                                        failed = -ENOMEM;
                                        goto error_cleanup;
                                }

                                assert(cipher_ctx.active && cipher_ctx.done);

                                if (cipher_ctx.unit_no == src_dma){
                                        /* mem2mem */
                                        ed_mo.ciphsel = src_none;
                                } else {
                                        ed_mo.ciphsel = cipher_ctx.current_src;
                                }
                                ed_mo.ciphconf = cipher_ctx.ciph_conf;
                                ed_mo.cbcmode = cipher_ctx.cbcmode;
                                ed_mo.decrypt = cipher_ctx.decrypt;

                                ed->free_buf = NULL;
                                ed->dma_descr->wait = 1;
                                ed->dma_descr->out_eop = 1;

                                ed->dma_descr->buf = (char*)virt_to_phys(&ed); /* Use any valid physical address for zero length descriptor. */
                                ed->dma_descr->after = ed->dma_descr->buf;
                                ed->dma_descr->md = REG_TYPE_CONV(unsigned short int, struct strcop_meta_out, ed_mo);
                                current_out_cdesc->next = ed;
                                current_out_cdesc = ed;
                        } else {
                                /* Set EOP in the current out descriptor since the only active module is
                                 * the one needing the EOP. */

                                current_out_cdesc->dma_descr->out_eop = 1;
                        }
                }

                if (cipher_ctx.done && cipher_ctx.active) cipher_ctx.active = 0;
                if (digest_ctx.done && digest_ctx.active) digest_ctx.active = 0;
                if (csum_ctx.done && csum_ctx.active) csum_ctx.active = 0;
                indata_ix += odsc->length;
                odsc = odsc->next;
        } /* while (odsc) */ /* Process descriptors. */
        DEBUG(printk("cryptocop_setup_dma_list: done parsing operation descriptors\n"));
        if (cipher_ctx.tcfg && (cipher_ctx.active || !cipher_ctx.done)){
                DEBUG_API(printk("cryptocop_setup_dma_list: cipher operation not terminated.\n"));
                failed = -EINVAL;
                goto error_cleanup;
        }
        if (digest_ctx.tcfg && (digest_ctx.active || !digest_ctx.done)){
                DEBUG_API(printk("cryptocop_setup_dma_list: digest operation not terminated.\n"));
                failed = -EINVAL;
                goto error_cleanup;
        }
        if (csum_ctx.tcfg && (csum_ctx.active || !csum_ctx.done)){
                DEBUG_API(printk("cryptocop_setup_dma_list: csum operation not terminated.\n"));
                failed = -EINVAL;
                goto error_cleanup;
        }

        failed = append_input_descriptors(operation, &current_in_cdesc, &current_out_cdesc, &cipher_ctx, alloc_flag);
        if (failed){
                DEBUG_API(printk("cryptocop_setup_dma_list: append_input_descriptors cipher_ctx %d\n", failed));
                goto error_cleanup;
        }
        failed = append_input_descriptors(operation, &current_in_cdesc, &current_out_cdesc, &digest_ctx, alloc_flag);
        if (failed){
                DEBUG_API(printk("cryptocop_setup_dma_list: append_input_descriptors cipher_ctx %d\n", failed));
                goto error_cleanup;
        }
        failed = append_input_descriptors(operation, &current_in_cdesc, &current_out_cdesc, &csum_ctx, alloc_flag);
        if (failed){
                DEBUG_API(printk("cryptocop_setup_dma_list: append_input_descriptors cipher_ctx %d\n", failed));
                goto error_cleanup;
        }

        DEBUG(printk("cryptocop_setup_dma_list: int_op=0x%p, *int_op=0x%p\n", int_op, *int_op));
        (*int_op)->cdesc_out = out_cdesc_head.next;
        (*int_op)->cdesc_in = in_cdesc_head.next;
        DEBUG(printk("cryptocop_setup_dma_list: out_cdesc_head=0x%p in_cdesc_head=0x%p\n", (*int_op)->cdesc_out, (*int_op)->cdesc_in));

        setup_descr_chain(out_cdesc_head.next);
        setup_descr_chain(in_cdesc_head.next);

        /* Last but not least: mark the last DMA in descriptor for a INTR and EOL and the the
         * last DMA out descriptor for EOL.
         */
        current_in_cdesc->dma_descr->intr = 1;
        current_in_cdesc->dma_descr->eol = 1;
        current_out_cdesc->dma_descr->eol = 1;

        /* Setup DMA contexts. */
        (*int_op)->ctx_out.next = NULL;
        (*int_op)->ctx_out.eol = 1;
        (*int_op)->ctx_out.intr = 0;
        (*int_op)->ctx_out.store_mode = 0;
        (*int_op)->ctx_out.en = 0;
        (*int_op)->ctx_out.dis = 0;
        (*int_op)->ctx_out.md0 = 0;
        (*int_op)->ctx_out.md1 = 0;
        (*int_op)->ctx_out.md2 = 0;
        (*int_op)->ctx_out.md3 = 0;
        (*int_op)->ctx_out.md4 = 0;
        (*int_op)->ctx_out.saved_data = (dma_descr_data*)virt_to_phys((*int_op)->cdesc_out->dma_descr);
        (*int_op)->ctx_out.saved_data_buf = (*int_op)->cdesc_out->dma_descr->buf; /* Already physical address. */

        (*int_op)->ctx_in.next = NULL;
        (*int_op)->ctx_in.eol = 1;
        (*int_op)->ctx_in.intr = 0;
        (*int_op)->ctx_in.store_mode = 0;
        (*int_op)->ctx_in.en = 0;
        (*int_op)->ctx_in.dis = 0;
        (*int_op)->ctx_in.md0 = 0;
        (*int_op)->ctx_in.md1 = 0;
        (*int_op)->ctx_in.md2 = 0;
        (*int_op)->ctx_in.md3 = 0;
        (*int_op)->ctx_in.md4 = 0;

        (*int_op)->ctx_in.saved_data = (dma_descr_data*)virt_to_phys((*int_op)->cdesc_in->dma_descr);
        (*int_op)->ctx_in.saved_data_buf = (*int_op)->cdesc_in->dma_descr->buf; /* Already physical address. */

        DEBUG(printk("cryptocop_setup_dma_list: done\n"));
        return 0;

error_cleanup:
        {
                /* Free all allocated resources. */
                struct cryptocop_dma_desc *tmp_cdesc;
                while (digest_ctx.pad_descs){
                        tmp_cdesc = digest_ctx.pad_descs->next;
                        free_cdesc(digest_ctx.pad_descs);
                        digest_ctx.pad_descs = tmp_cdesc;
                }
                while (csum_ctx.pad_descs){
                        tmp_cdesc = csum_ctx.pad_descs->next;
                        free_cdesc(csum_ctx.pad_descs);
                        csum_ctx.pad_descs = tmp_cdesc;
                }
                assert(cipher_ctx.pad_descs == NULL); /* The ciphers are never padded. */

                if (*int_op != NULL) delete_internal_operation(*int_op);
        }
        DEBUG_API(printk("cryptocop_setup_dma_list: done with error %d\n", failed));
        return failed;
}


static void delete_internal_operation(struct cryptocop_int_operation *iop)
{
        void                      *ptr = iop->alloc_ptr;
        struct cryptocop_dma_desc *cd = iop->cdesc_out;
        struct cryptocop_dma_desc *next;

        DEBUG(printk("delete_internal_operation: iop=0x%p, alloc_ptr=0x%p\n", iop, ptr));

        while (cd) {
                next = cd->next;
                free_cdesc(cd);
                cd = next;
        }
        cd = iop->cdesc_in;
        while (cd) {
                next = cd->next;
                free_cdesc(cd);
                cd = next;
        }
        kfree(ptr);
}

#define MD5_MIN_PAD_LENGTH (9)
#define MD5_PAD_LENGTH_FIELD_LENGTH (8)

static int create_md5_pad(int alloc_flag, unsigned long long hashed_length, char **pad, size_t *pad_length)
{
        size_t                  padlen = MD5_BLOCK_LENGTH - (hashed_length % MD5_BLOCK_LENGTH);
        unsigned char           *p;
        int                     i;
        unsigned long long int  bit_length = hashed_length << 3;

        if (padlen < MD5_MIN_PAD_LENGTH) padlen += MD5_BLOCK_LENGTH;

        p = kmalloc(padlen, alloc_flag);
        if (!p) return -ENOMEM;

        *p = 0x80;
        memset(p+1, 0, padlen - 1);

        DEBUG(printk("create_md5_pad: hashed_length=%lld bits == %lld bytes\n", bit_length, hashed_length));

        i = padlen - MD5_PAD_LENGTH_FIELD_LENGTH;
        while (bit_length != 0){
                p[i++] = bit_length % 0x100;
                bit_length >>= 8;
        }

        *pad = (char*)p;
        *pad_length = padlen;

        return 0;
}

#define SHA1_MIN_PAD_LENGTH (9)
#define SHA1_PAD_LENGTH_FIELD_LENGTH (8)

static int create_sha1_pad(int alloc_flag, unsigned long long hashed_length, char **pad, size_t *pad_length)
{
        size_t                  padlen = SHA1_BLOCK_LENGTH - (hashed_length % SHA1_BLOCK_LENGTH);
        unsigned char           *p;
        int                     i;
        unsigned long long int  bit_length = hashed_length << 3;

        if (padlen < SHA1_MIN_PAD_LENGTH) padlen += SHA1_BLOCK_LENGTH;

        p = kmalloc(padlen, alloc_flag);
        if (!p) return -ENOMEM;

        *p = 0x80;
        memset(p+1, 0, padlen - 1);

        DEBUG(printk("create_sha1_pad: hashed_length=%lld bits == %lld bytes\n", bit_length, hashed_length));

        i = padlen - 1;
        while (bit_length != 0){
                p[i--] = bit_length % 0x100;
                bit_length >>= 8;
        }

        *pad = (char*)p;
        *pad_length = padlen;

        return 0;
}


static int transform_ok(struct cryptocop_transform_init *tinit)
{
        switch (tinit->alg){
        case cryptocop_alg_csum:
                switch (tinit->csum_mode){
                case cryptocop_csum_le:
                case cryptocop_csum_be:
                        break;
                default:
                        DEBUG_API(printk("transform_ok: Bad mode set for csum transform\n"));
                        return -EINVAL;
                }
        case cryptocop_alg_mem2mem:
        case cryptocop_alg_md5:
        case cryptocop_alg_sha1:
                if (tinit->keylen != 0) {
                        DEBUG_API(printk("transform_ok: non-zero keylength, %d, for a digest/csum algorithm\n", tinit->keylen));
                        return -EINVAL; /* This check is a bit strict. */
                }
                break;
        case cryptocop_alg_des:
                if (tinit->keylen != 64) {
                        DEBUG_API(printk("transform_ok: keylen %d invalid for DES\n", tinit->keylen));
                        return -EINVAL;
                }
                break;
        case cryptocop_alg_3des:
                if (tinit->keylen != 192) {
                        DEBUG_API(printk("transform_ok: keylen %d invalid for 3DES\n", tinit->keylen));
                        return -EINVAL;
                }
                break;
        case cryptocop_alg_aes:
                if (tinit->keylen != 128 && tinit->keylen != 192 && tinit->keylen != 256) {
                        DEBUG_API(printk("transform_ok: keylen %d invalid for AES\n", tinit->keylen));
                        return -EINVAL;
                }
                break;
        case cryptocop_no_alg:
        default:
                DEBUG_API(printk("transform_ok: no such algorithm %d\n", tinit->alg));
                return -EINVAL;
        }

        switch (tinit->alg){
        case cryptocop_alg_des:
        case cryptocop_alg_3des:
        case cryptocop_alg_aes:
                if (tinit->cipher_mode != cryptocop_cipher_mode_ecb && tinit->cipher_mode != cryptocop_cipher_mode_cbc) return -EINVAL;
        default:
                 break;
        }
        return 0;
}


int cryptocop_new_session(cryptocop_session_id *sid, struct cryptocop_transform_init *tinit, int alloc_flag)
{
        struct cryptocop_session         *sess;
        struct cryptocop_transform_init  *tfrm_in = tinit;
        struct cryptocop_transform_init  *tmp_in;
        int                              no_tfrms = 0;
        int                              i;
        unsigned long int                flags;

        init_stream_coprocessor(); /* For safety if we are called early */

        while (tfrm_in){
                int err;
                ++no_tfrms;
                if ((err = transform_ok(tfrm_in))) {
                        DEBUG_API(printk("cryptocop_new_session, bad transform\n"));
                        return err;
                }
                tfrm_in = tfrm_in->next;
        }
        if (0 == no_tfrms) {
                DEBUG_API(printk("cryptocop_new_session, no transforms specified\n"));
                return -EINVAL;
        }

        sess = kmalloc(sizeof(struct cryptocop_session), alloc_flag);
        if (!sess){
                DEBUG_API(printk("cryptocop_new_session, kmalloc cryptocop_session\n"));
                return -ENOMEM;
        }

        sess->tfrm_ctx = kmalloc(no_tfrms * sizeof(struct cryptocop_transform_ctx), alloc_flag);
        if (!sess->tfrm_ctx) {
                DEBUG_API(printk("cryptocop_new_session, kmalloc cryptocop_transform_ctx\n"));
                kfree(sess);
                return -ENOMEM;
        }

        tfrm_in = tinit;
        for (i = 0; i < no_tfrms; i++){
                tmp_in = tfrm_in->next;
                while (tmp_in){
                        if (tmp_in->tid == tfrm_in->tid) {
                                DEBUG_API(printk("cryptocop_new_session, duplicate transform ids\n"));
                                kfree(sess->tfrm_ctx);
                                kfree(sess);
                                return -EINVAL;
                        }
                        tmp_in = tmp_in->next;
                }
                memcpy(&sess->tfrm_ctx[i].init, tfrm_in, sizeof(struct cryptocop_transform_init));
                sess->tfrm_ctx[i].dec_key_set = 0;
                sess->tfrm_ctx[i].next = &sess->tfrm_ctx[i] + 1;

                tfrm_in = tfrm_in->next;
        }
        sess->tfrm_ctx[i-1].next = NULL;

        spin_lock_irqsave(&cryptocop_sessions_lock, flags);
        sess->sid = next_sid;
        next_sid++;
        /* TODO If we are really paranoid we should do duplicate check to handle sid wraparound.
         *      OTOH 2^64 is a really large number of session. */
        if (next_sid == 0) next_sid = 1;

        /* Prepend to session list. */
        sess->next = cryptocop_sessions;
        cryptocop_sessions = sess;
        spin_unlock_irqrestore(&cryptocop_sessions_lock, flags);
        *sid = sess->sid;
        return 0;
}


int cryptocop_free_session(cryptocop_session_id sid)
{
        struct cryptocop_transform_ctx    *tc;
        struct cryptocop_session          *sess = NULL;
        struct cryptocop_session          *psess = NULL;
        unsigned long int                 flags;
        int                               i;
        LIST_HEAD(remove_list);
        struct list_head                  *node, *tmp;
        struct cryptocop_prio_job         *pj;

        DEBUG(printk("cryptocop_free_session: sid=%lld\n", sid));

        spin_lock_irqsave(&cryptocop_sessions_lock, flags);
        sess = cryptocop_sessions;
        while (sess && sess->sid != sid){
                psess = sess;
                sess = sess->next;
        }
        if (sess){
                if (psess){
                        psess->next = sess->next;
                } else {
                        cryptocop_sessions = sess->next;
                }
        }
        spin_unlock_irqrestore(&cryptocop_sessions_lock, flags);

        if (!sess) return -EINVAL;

        /* Remove queued jobs. */
        spin_lock_irqsave(&cryptocop_job_queue_lock, flags);

        for (i = 0; i < cryptocop_prio_no_prios; i++){
                if (!list_empty(&(cryptocop_job_queues[i].jobs))){
                        list_for_each_safe(node, tmp, &(cryptocop_job_queues[i].jobs)) {
                                pj = list_entry(node, struct cryptocop_prio_job, node);
                                if (pj->oper->sid == sid) {
                                        list_move_tail(node, &remove_list);
                                }
                        }
                }
        }
        spin_unlock_irqrestore(&cryptocop_job_queue_lock, flags);

        list_for_each_safe(node, tmp, &remove_list) {
                list_del(node);
                pj = list_entry(node, struct cryptocop_prio_job, node);
                pj->oper->operation_status = -EAGAIN;  /* EAGAIN is not ideal for job/session terminated but it's the best choice I know of. */
                DEBUG(printk("cryptocop_free_session: pj=0x%p, pj->oper=0x%p, pj->iop=0x%p\n", pj, pj->oper, pj->iop));
                pj->oper->cb(pj->oper, pj->oper->cb_data);
                delete_internal_operation(pj->iop);
                kfree(pj);
        }

        tc = sess->tfrm_ctx;
        /* Erase keying data. */
        while (tc){
                DEBUG(printk("cryptocop_free_session: memset keys, tfrm id=%d\n", tc->init.tid));
                memset(tc->init.key, 0xff, CRYPTOCOP_MAX_KEY_LENGTH);
                memset(tc->dec_key, 0xff, CRYPTOCOP_MAX_KEY_LENGTH);
                tc = tc->next;
        }
        kfree(sess->tfrm_ctx);
        kfree(sess);

        return 0;
}

static struct cryptocop_session *get_session(cryptocop_session_id sid)
{
        struct cryptocop_session    *sess;
        unsigned long int           flags;

        spin_lock_irqsave(&cryptocop_sessions_lock, flags);
        sess = cryptocop_sessions;
        while (sess && (sess->sid != sid)){
                sess = sess->next;
        }
        spin_unlock_irqrestore(&cryptocop_sessions_lock, flags);

        return sess;
}

static struct cryptocop_transform_ctx *get_transform_ctx(struct cryptocop_session *sess, cryptocop_tfrm_id tid)
{
        struct cryptocop_transform_ctx *tc = sess->tfrm_ctx;

        DEBUG(printk("get_transform_ctx, sess=0x%p, tid=%d\n", sess, tid));
        assert(sess != NULL);
        while (tc && tc->init.tid != tid){
                DEBUG(printk("tc=0x%p, tc->next=0x%p\n", tc, tc->next));
                tc = tc->next;
        }
        DEBUG(printk("get_transform_ctx, returning tc=0x%p\n", tc));
        return tc;
}



/* The AES s-transform matrix (s-box). */
static const u8 aes_sbox[256] = {
        99,  124, 119, 123, 242, 107, 111, 197, 48,  1,   103, 43,  254, 215, 171, 118,
        202, 130, 201, 125, 250, 89,  71,  240, 173, 212, 162, 175, 156, 164, 114, 192,
        183, 253, 147, 38,  54,  63,  247, 204, 52,  165, 229, 241, 113, 216, 49,  21,
        4,   199, 35,  195, 24,  150, 5,   154, 7,   18,  128, 226, 235, 39,  178, 117,
        9,   131, 44,  26,  27,  110, 90,  160, 82,  59,  214, 179, 41,  227, 47,  132,
        83,  209, 0,   237, 32,  252, 177, 91,  106, 203, 190, 57,  74,  76,  88,  207,
        208, 239, 170, 251, 67,  77,  51,  133, 69,  249, 2,   127, 80,  60,  159, 168,
        81,  163, 64,  143, 146, 157, 56,  245, 188, 182, 218, 33,  16,  255, 243, 210,
        205, 12,  19,  236, 95,  151, 68,  23,  196, 167, 126, 61,  100, 93,  25,  115,
        96,  129, 79,  220, 34,  42,  144, 136, 70,  238, 184, 20,  222, 94,  11,  219,
        224, 50,  58,  10,  73,  6,   36,  92,  194, 211, 172, 98,  145, 149, 228, 121,
        231, 200, 55,  109, 141, 213, 78,  169, 108, 86,  244, 234, 101, 122, 174, 8,
        186, 120, 37,  46,  28,  166, 180, 198, 232, 221, 116, 31,  75,  189, 139, 138,
        112, 62,  181, 102, 72,  3,   246, 14,  97,  53,  87,  185, 134, 193, 29,  158,
        225, 248, 152, 17,  105, 217, 142, 148, 155, 30,  135, 233, 206, 85,  40,  223,
        140, 161, 137, 13,  191, 230, 66,  104, 65,  153, 45,  15,  176, 84,  187, 22
};

/* AES has a 32 bit word round constants for each round in the
 * key schedule.  round_constant[i] is really Rcon[i+1] in FIPS187.
 */
static u32 round_constant[11] = {
        0x01000000, 0x02000000, 0x04000000, 0x08000000,
        0x10000000, 0x20000000, 0x40000000, 0x80000000,
        0x1B000000, 0x36000000, 0x6C000000
};

/* Apply the s-box to each of the four occtets in w. */
static u32 aes_ks_subword(const u32 w)
{
        u8 bytes[4];

        *(u32*)(&bytes[0]) = w;
        bytes[0] = aes_sbox[bytes[0]];
        bytes[1] = aes_sbox[bytes[1]];
        bytes[2] = aes_sbox[bytes[2]];
        bytes[3] = aes_sbox[bytes[3]];
        return *(u32*)(&bytes[0]);
}

/* The encrypt (forward) Rijndael key schedule algorithm pseudo code:
 * (Note that AES words are 32 bit long)
 *
 * KeyExpansion(byte key[4*Nk], word w[Nb*(Nr+1)], Nk){
 * word temp
 * i = 0
 * while (i < Nk) {
 *   w[i] = word(key[4*i, 4*i + 1, 4*i + 2, 4*i + 3])
 *   i = i + 1
 * }
 * i = Nk
 *
 * while (i < (Nb * (Nr + 1))) {
 *   temp = w[i - 1]
 *   if ((i mod Nk) == 0) {
 *     temp = SubWord(RotWord(temp)) xor Rcon[i/Nk]
 *   }
 *   else if ((Nk > 6) && ((i mod Nk) == 4)) {
 *     temp = SubWord(temp)
 *   }
 *   w[i] = w[i - Nk] xor temp
 * }
 * RotWord(t) does a 8 bit cyclic shift left on a 32 bit word.
 * SubWord(t) applies the AES s-box individually to each octet
 * in a 32 bit word.
 *
 * For AES Nk can have the values 4, 6, and 8 (corresponding to
 * values for Nr of 10, 12, and 14).  Nb is always 4.
 *
 * To construct w[i], w[i - 1] and w[i - Nk] must be
 * available.  Consequently we must keep a state of the last Nk words
 * to be able to create the last round keys.
 */
static void get_aes_decrypt_key(unsigned char *dec_key, const unsigned  char *key, unsigned int keylength)
{
        u32 temp;
        u32 w_ring[8]; /* nk is max 8, use elements 0..(nk - 1) as a ringbuffer */
        u8  w_last_ix;
        int i;
        u8  nr, nk;

        switch (keylength){
        case 128:
                nk = 4;
                nr = 10;
                break;
        case 192:
                nk = 6;
                nr = 12;
                break;
        case 256:
                nk = 8;
                nr = 14;
                break;
        default:
                panic("stream co-processor: bad aes key length in get_aes_decrypt_key\n");
        };

        /* Need to do host byte order correction here since key is byte oriented and the
         * kx algorithm is word (u32) oriented. */
        for (i = 0; i < nk; i+=1) {
                w_ring[i] = be32_to_cpu(*(u32*)&key[4*i]);
        }

        i = (int)nk;
        w_last_ix = i - 1;
        while (i < (4 * (nr + 2))) {
                temp = w_ring[w_last_ix];
                if (!(i % nk)) {
                        /* RotWord(temp) */
                        temp = (temp << 8) | (temp >> 24);
                        temp = aes_ks_subword(temp);
                        temp ^= round_constant[i/nk - 1];
                } else if ((nk > 6) && ((i % nk) == 4)) {
                        temp = aes_ks_subword(temp);
                }
                w_last_ix = (w_last_ix + 1) % nk; /* This is the same as (i-Nk) mod Nk */
                temp ^= w_ring[w_last_ix];
                w_ring[w_last_ix] = temp;

                /* We need the round keys for round Nr+1 and Nr+2 (round key
                 * Nr+2 is the round key beyond the last one used when
                 * encrypting).  Rounds are numbered starting from 0, Nr=10
                 * implies 11 rounds are used in encryption/decryption.
                 */
                if (i >= (4 * nr)) {
                        /* Need to do host byte order correction here, the key
                         * is byte oriented. */
                        *(u32*)dec_key = cpu_to_be32(temp);
                        dec_key += 4;
                }
                ++i;
        }
}


/**** Job/operation management. ****/

int cryptocop_job_queue_insert_csum(struct cryptocop_operation *operation)
{
        return cryptocop_job_queue_insert(cryptocop_prio_kernel_csum, operation);
}

int cryptocop_job_queue_insert_crypto(struct cryptocop_operation *operation)
{
        return cryptocop_job_queue_insert(cryptocop_prio_kernel, operation);
}

int cryptocop_job_queue_insert_user_job(struct cryptocop_operation *operation)
{
        return cryptocop_job_queue_insert(cryptocop_prio_user, operation);
}

static int cryptocop_job_queue_insert(cryptocop_queue_priority prio, struct cryptocop_operation *operation)
{
        int                           ret;
        struct cryptocop_prio_job     *pj = NULL;
        unsigned long int             flags;

        DEBUG(printk("cryptocop_job_queue_insert(%d, 0x%p)\n", prio, operation));

        if (!operation || !operation->cb){
                DEBUG_API(printk("cryptocop_job_queue_insert oper=0x%p, NULL operation or callback\n", operation));
                return -EINVAL;
        }

        if ((ret = cryptocop_job_setup(&pj, operation)) != 0){
                DEBUG_API(printk("cryptocop_job_queue_insert: job setup failed\n"));
                return ret;
        }
        assert(pj != NULL);

        spin_lock_irqsave(&cryptocop_job_queue_lock, flags);
        list_add_tail(&pj->node, &cryptocop_job_queues[prio].jobs);
        spin_unlock_irqrestore(&cryptocop_job_queue_lock, flags);

        /* Make sure a job is running */
        cryptocop_start_job();
        return 0;
}

static void cryptocop_do_tasklet(unsigned long unused);
DECLARE_TASKLET (cryptocop_tasklet, cryptocop_do_tasklet, 0);

static void cryptocop_do_tasklet(unsigned long unused)
{
        struct list_head             *node;
        struct cryptocop_prio_job    *pj = NULL;
        unsigned long                flags;

        DEBUG(printk("cryptocop_do_tasklet: entering\n"));

        do {
                spin_lock_irqsave(&cryptocop_completed_jobs_lock, flags);
                if (!list_empty(&cryptocop_completed_jobs)){
                        node = cryptocop_completed_jobs.next;
                        list_del(node);
                        pj = list_entry(node, struct cryptocop_prio_job, node);
                } else {
                        pj = NULL;
                }
                spin_unlock_irqrestore(&cryptocop_completed_jobs_lock, flags);
                if (pj) {
                        assert(pj->oper != NULL);

                        /* Notify consumer of operation completeness. */
                        DEBUG(printk("cryptocop_do_tasklet: callback 0x%p, data 0x%p\n", pj->oper->cb, pj->oper->cb_data));

                        pj->oper->operation_status = 0; /* Job is completed. */
                        pj->oper->cb(pj->oper, pj->oper->cb_data);
                        delete_internal_operation(pj->iop);
                        kfree(pj);
                }
        } while (pj != NULL);

        DEBUG(printk("cryptocop_do_tasklet: exiting\n"));
}

static irqreturn_t
dma_done_interrupt(int irq, void *dev_id)
{
        struct cryptocop_prio_job *done_job;
        reg_dma_rw_ack_intr ack_intr = {
                .data = 1,
        };

        REG_WR(dma, IN_DMA_INST, rw_ack_intr, ack_intr);

        DEBUG(printk("cryptocop DMA done\n"));

        spin_lock(&running_job_lock);
        if (cryptocop_running_job == NULL){
                printk("stream co-processor got interrupt when not busy\n");
                spin_unlock(&running_job_lock);
                return IRQ_HANDLED;
        }
        done_job = cryptocop_running_job;
        cryptocop_running_job = NULL;
        spin_unlock(&running_job_lock);

        /* Start processing a job. */
        if (!spin_trylock(&cryptocop_process_lock)){
                DEBUG(printk("cryptocop irq handler, not starting a job\n"));
        } else {
                cryptocop_start_job();
                spin_unlock(&cryptocop_process_lock);
        }

        done_job->oper->operation_status = 0; /* Job is completed. */
        if (done_job->oper->fast_callback){
                /* This operation wants callback from interrupt. */
                done_job->oper->cb(done_job->oper, done_job->oper->cb_data);
                delete_internal_operation(done_job->iop);
                kfree(done_job);
        } else {
                spin_lock(&cryptocop_completed_jobs_lock);
                list_add_tail(&(done_job->node), &cryptocop_completed_jobs);
                spin_unlock(&cryptocop_completed_jobs_lock);
                tasklet_schedule(&cryptocop_tasklet);
        }

        DEBUG(printk("cryptocop leave irq handler\n"));
        return IRQ_HANDLED;
}


/* Setup interrupts and DMA channels. */
static int init_cryptocop(void)
{
        unsigned long          flags;
        reg_dma_rw_cfg         dma_cfg = {.en = 1};
        reg_dma_rw_intr_mask   intr_mask_in = {.data = regk_dma_yes}; /* Only want descriptor interrupts from the DMA in channel. */
        reg_dma_rw_ack_intr    ack_intr = {.data = 1,.in_eop = 1 };
        reg_strcop_rw_cfg      strcop_cfg = {
                .ipend = regk_strcop_little,
                .td1 = regk_strcop_e,
                .td2 = regk_strcop_d,
                .td3 = regk_strcop_e,
                .ignore_sync = 0,
                .en = 1
        };

        if (request_irq(DMA_IRQ, dma_done_interrupt, 0,
                        "stream co-processor DMA", NULL))
                panic("request_irq stream co-processor irq dma9");

        (void)crisv32_request_dma(OUT_DMA, "strcop", DMA_PANIC_ON_ERROR,
                0, dma_strp);
        (void)crisv32_request_dma(IN_DMA, "strcop", DMA_PANIC_ON_ERROR,
                0, dma_strp);

        local_irq_save(flags);

        /* Reset and enable the cryptocop. */
        strcop_cfg.en = 0;
        REG_WR(strcop, regi_strcop, rw_cfg, strcop_cfg);
        strcop_cfg.en = 1;
        REG_WR(strcop, regi_strcop, rw_cfg, strcop_cfg);

        /* Enable DMAs. */
        REG_WR(dma, IN_DMA_INST, rw_cfg, dma_cfg); /* input DMA */
        REG_WR(dma, OUT_DMA_INST, rw_cfg, dma_cfg); /* output DMA */

        /* Set up wordsize = 4 for DMAs. */
        DMA_WR_CMD(OUT_DMA_INST, regk_dma_set_w_size4);
        DMA_WR_CMD(IN_DMA_INST, regk_dma_set_w_size4);

        /* Enable interrupts. */
        REG_WR(dma, IN_DMA_INST, rw_intr_mask, intr_mask_in);

        /* Clear intr ack. */
        REG_WR(dma, IN_DMA_INST, rw_ack_intr, ack_intr);

        local_irq_restore(flags);

        return 0;
}

/* Free used cryptocop hw resources (interrupt and DMA channels). */

static void release_cryptocop(void)
{
        unsigned long          flags;
        reg_dma_rw_cfg         dma_cfg = {.en = 0};
        reg_dma_rw_intr_mask   intr_mask_in = {0};
        reg_dma_rw_ack_intr    ack_intr = {.data = 1,.in_eop = 1 };

        local_irq_save(flags);

        /* Clear intr ack. */
        REG_WR(dma, IN_DMA_INST, rw_ack_intr, ack_intr);

        /* Disable DMAs. */
        REG_WR(dma, IN_DMA_INST, rw_cfg, dma_cfg); /* input DMA */
        REG_WR(dma, OUT_DMA_INST, rw_cfg, dma_cfg); /* output DMA */

        /* Disable interrupts. */
        REG_WR(dma, IN_DMA_INST, rw_intr_mask, intr_mask_in);

        local_irq_restore(flags);

        free_irq(DMA_IRQ, NULL);

        (void)crisv32_free_dma(OUT_DMA);
        (void)crisv32_free_dma(IN_DMA);
}


/* Init job queue. */
static int cryptocop_job_queue_init(void)
{
        int i;

        INIT_LIST_HEAD(&cryptocop_completed_jobs);

        for (i = 0; i < cryptocop_prio_no_prios; i++){
                cryptocop_job_queues[i].prio = (cryptocop_queue_priority)i;
                INIT_LIST_HEAD(&cryptocop_job_queues[i].jobs);
        }
        return 0;
}


static void cryptocop_job_queue_close(void)
{
        struct list_head               *node, *tmp;
        struct cryptocop_prio_job      *pj = NULL;
        unsigned long int              process_flags, flags;
        int                            i;

        /* FIXME: This is as yet untested code. */

        /* Stop strcop from getting an operation to process while we are closing the
           module. */
        spin_lock_irqsave(&cryptocop_process_lock, process_flags);

        /* Empty the job queue. */
        for (i = 0; i < cryptocop_prio_no_prios; i++){
                if (!list_empty(&(cryptocop_job_queues[i].jobs))){
                        list_for_each_safe(node, tmp, &(cryptocop_job_queues[i].jobs)) {
                                pj = list_entry(node, struct cryptocop_prio_job, node);
                                list_del(node);

                                /* Call callback to notify consumer of job removal. */
                                DEBUG(printk("cryptocop_job_queue_close: callback 0x%p, data 0x%p\n", pj->oper->cb, pj->oper->cb_data));
                                pj->oper->operation_status = -EINTR; /* Job is terminated without completion. */
                                pj->oper->cb(pj->oper, pj->oper->cb_data);

                                delete_internal_operation(pj->iop);
                                kfree(pj);
                        }
                }
        }
        spin_unlock_irqrestore(&cryptocop_process_lock, process_flags);

        /* Remove the running job, if any. */
        spin_lock_irqsave(&running_job_lock, flags);
        if (cryptocop_running_job){
                reg_strcop_rw_cfg rw_cfg;
                reg_dma_rw_cfg    dma_out_cfg, dma_in_cfg;

                /* Stop DMA. */
                dma_out_cfg = REG_RD(dma, OUT_DMA_INST, rw_cfg);
                dma_out_cfg.en = regk_dma_no;
                REG_WR(dma, OUT_DMA_INST, rw_cfg, dma_out_cfg);

                dma_in_cfg = REG_RD(dma, IN_DMA_INST, rw_cfg);
                dma_in_cfg.en = regk_dma_no;
                REG_WR(dma, IN_DMA_INST, rw_cfg, dma_in_cfg);

                /* Disble the cryptocop. */
                rw_cfg = REG_RD(strcop, regi_strcop, rw_cfg);
                rw_cfg.en = 0;
                REG_WR(strcop, regi_strcop, rw_cfg, rw_cfg);

                pj = cryptocop_running_job;
                cryptocop_running_job = NULL;

                /* Call callback to notify consumer of job removal. */
                DEBUG(printk("cryptocop_job_queue_close: callback 0x%p, data 0x%p\n", pj->oper->cb, pj->oper->cb_data));
                pj->oper->operation_status = -EINTR; /* Job is terminated without completion. */
                pj->oper->cb(pj->oper, pj->oper->cb_data);

                delete_internal_operation(pj->iop);
                kfree(pj);
        }
        spin_unlock_irqrestore(&running_job_lock, flags);

        /* Remove completed jobs, if any. */
        spin_lock_irqsave(&cryptocop_completed_jobs_lock, flags);

        list_for_each_safe(node, tmp, &cryptocop_completed_jobs) {
                pj = list_entry(node, struct cryptocop_prio_job, node);
                list_del(node);
                /* Call callback to notify consumer of job removal. */
                DEBUG(printk("cryptocop_job_queue_close: callback 0x%p, data 0x%p\n", pj->oper->cb, pj->oper->cb_data));
                pj->oper->operation_status = -EINTR; /* Job is terminated without completion. */
                pj->oper->cb(pj->oper, pj->oper->cb_data);

                delete_internal_operation(pj->iop);
                kfree(pj);
        }
        spin_unlock_irqrestore(&cryptocop_completed_jobs_lock, flags);
}


static void cryptocop_start_job(void)
{
        int                          i;
        struct cryptocop_prio_job    *pj;
        unsigned long int            flags;
        unsigned long int            running_job_flags;
        reg_strcop_rw_cfg            rw_cfg = {.en = 1, .ignore_sync = 0};

        DEBUG(printk("cryptocop_start_job: entering\n"));

        spin_lock_irqsave(&running_job_lock, running_job_flags);
        if (cryptocop_running_job != NULL){
                /* Already running. */
                DEBUG(printk("cryptocop_start_job: already running, exit\n"));
                spin_unlock_irqrestore(&running_job_lock, running_job_flags);
                return;
        }
        spin_lock_irqsave(&cryptocop_job_queue_lock, flags);

        /* Check the queues in priority order. */
        for (i = cryptocop_prio_kernel_csum; (i < cryptocop_prio_no_prios) && list_empty(&cryptocop_job_queues[i].jobs); i++);
        if (i == cryptocop_prio_no_prios) {
                spin_unlock_irqrestore(&cryptocop_job_queue_lock, flags);
                spin_unlock_irqrestore(&running_job_lock, running_job_flags);
                DEBUG(printk("cryptocop_start_job: no jobs to run\n"));
                return; /* No jobs to run */
        }
        DEBUG(printk("starting job for prio %d\n", i));

        /* TODO: Do not starve lower priority jobs.  Let in a lower
         * prio job for every N-th processed higher prio job or some
         * other scheduling policy.  This could reasonably be
         * tweakable since the optimal balance would depend on the
         * type of load on the system. */

        /* Pull the DMA lists from the job and start the DMA client. */
        pj = list_entry(cryptocop_job_queues[i].jobs.next, struct cryptocop_prio_job, node);
        list_del(&pj->node);
        spin_unlock_irqrestore(&cryptocop_job_queue_lock, flags);
        cryptocop_running_job = pj;

        /* Set config register (3DES and CSUM modes). */
        switch (pj->iop->tdes_mode){
        case cryptocop_3des_eee:
                rw_cfg.td1 = regk_strcop_e;
                rw_cfg.td2 = regk_strcop_e;
                rw_cfg.td3 = regk_strcop_e;
                break;
        case cryptocop_3des_eed:
                rw_cfg.td1 = regk_strcop_e;
                rw_cfg.td2 = regk_strcop_e;
                rw_cfg.td3 = regk_strcop_d;
                break;
        case cryptocop_3des_ede:
                rw_cfg.td1 = regk_strcop_e;
                rw_cfg.td2 = regk_strcop_d;
                rw_cfg.td3 = regk_strcop_e;
                break;
        case cryptocop_3des_edd:
                rw_cfg.td1 = regk_strcop_e;
                rw_cfg.td2 = regk_strcop_d;
                rw_cfg.td3 = regk_strcop_d;
                break;
        case cryptocop_3des_dee:
                rw_cfg.td1 = regk_strcop_d;
                rw_cfg.td2 = regk_strcop_e;
                rw_cfg.td3 = regk_strcop_e;
                break;
        case cryptocop_3des_ded:
                rw_cfg.td1 = regk_strcop_d;
                rw_cfg.td2 = regk_strcop_e;
                rw_cfg.td3 = regk_strcop_d;
                break;
        case cryptocop_3des_dde:
                rw_cfg.td1 = regk_strcop_d;
                rw_cfg.td2 = regk_strcop_d;
                rw_cfg.td3 = regk_strcop_e;
                break;
        case cryptocop_3des_ddd:
                rw_cfg.td1 = regk_strcop_d;
                rw_cfg.td2 = regk_strcop_d;
                rw_cfg.td3 = regk_strcop_d;
                break;
        default:
                DEBUG(printk("cryptocop_setup_dma_list: bad 3DES mode\n"));
        }
        switch (pj->iop->csum_mode){
        case cryptocop_csum_le:
                rw_cfg.ipend = regk_strcop_little;
                break;
        case cryptocop_csum_be:
                rw_cfg.ipend = regk_strcop_big;
                break;
        default:
                DEBUG(printk("cryptocop_setup_dma_list: bad checksum mode\n"));
        }
        REG_WR(strcop, regi_strcop, rw_cfg, rw_cfg);

        DEBUG(printk("cryptocop_start_job: starting DMA, new cryptocop_running_job=0x%p\n"
                     "ctx_in: 0x%p, phys: 0x%p\n"
                     "ctx_out: 0x%p, phys: 0x%p\n",
                     pj,
                     &pj->iop->ctx_in, (char*)virt_to_phys(&pj->iop->ctx_in),
                     &pj->iop->ctx_out, (char*)virt_to_phys(&pj->iop->ctx_out)));

        /* Start input DMA. */
        flush_dma_context(&pj->iop->ctx_in);
        DMA_START_CONTEXT(IN_DMA_INST, virt_to_phys(&pj->iop->ctx_in));

        /* Start output DMA. */
        DMA_START_CONTEXT(OUT_DMA_INST, virt_to_phys(&pj->iop->ctx_out));

        spin_unlock_irqrestore(&running_job_lock, running_job_flags);
        DEBUG(printk("cryptocop_start_job: exiting\n"));
}


static int cryptocop_job_setup(struct cryptocop_prio_job **pj, struct cryptocop_operation *operation)
{
        int  err;
        int  alloc_flag = operation->in_interrupt ? GFP_ATOMIC : GFP_KERNEL;
        void *iop_alloc_ptr = NULL;

        *pj = kmalloc(sizeof (struct cryptocop_prio_job), alloc_flag);
        if (!*pj) return -ENOMEM;

        DEBUG(printk("cryptocop_job_setup: operation=0x%p\n", operation));

        (*pj)->oper = operation;
        DEBUG(printk("cryptocop_job_setup, cb=0x%p cb_data=0x%p\n",  (*pj)->oper->cb, (*pj)->oper->cb_data));

        if (operation->use_dmalists) {
                DEBUG(print_user_dma_lists(&operation->list_op));
                if (!operation->list_op.inlist || !operation->list_op.outlist || !operation->list_op.out_data_buf || !operation->list_op.in_data_buf){
                        DEBUG_API(printk("cryptocop_job_setup: bad indata (use_dmalists)\n"));
                        kfree(*pj);
                        return -EINVAL;
                }
                iop_alloc_ptr = kmalloc(DESCR_ALLOC_PAD + sizeof(struct cryptocop_int_operation), alloc_flag);
                if (!iop_alloc_ptr) {
                        DEBUG_API(printk("cryptocop_job_setup: kmalloc cryptocop_int_operation\n"));
                        kfree(*pj);
                        return -ENOMEM;
                }
                (*pj)->iop = (struct cryptocop_int_operation*)(((unsigned long int)(iop_alloc_ptr + DESCR_ALLOC_PAD + offsetof(struct cryptocop_int_operation, ctx_out)) & ~0x0000001F) - offsetof(struct cryptocop_int_operation, ctx_out));
                DEBUG(memset((*pj)->iop, 0xff, sizeof(struct cryptocop_int_operation)));
                (*pj)->iop->alloc_ptr = iop_alloc_ptr;
                (*pj)->iop->sid = operation->sid;
                (*pj)->iop->cdesc_out = NULL;
                (*pj)->iop->cdesc_in = NULL;
                (*pj)->iop->tdes_mode = operation->list_op.tdes_mode;
                (*pj)->iop->csum_mode = operation->list_op.csum_mode;
                (*pj)->iop->ddesc_out = operation->list_op.outlist;
                (*pj)->iop->ddesc_in = operation->list_op.inlist;

                /* Setup DMA contexts. */
                (*pj)->iop->ctx_out.next = NULL;
                (*pj)->iop->ctx_out.eol = 1;
                (*pj)->iop->ctx_out.saved_data = operation->list_op.outlist;
                (*pj)->iop->ctx_out.saved_data_buf = operation->list_op.out_data_buf;

                (*pj)->iop->ctx_in.next = NULL;
                (*pj)->iop->ctx_in.eol = 1;
                (*pj)->iop->ctx_in.saved_data = operation->list_op.inlist;
                (*pj)->iop->ctx_in.saved_data_buf = operation->list_op.in_data_buf;
        } else {
                if ((err = cryptocop_setup_dma_list(operation, &(*pj)->iop, alloc_flag))) {
                        DEBUG_API(printk("cryptocop_job_setup: cryptocop_setup_dma_list failed %d\n", err));
                        kfree(*pj);
                        return err;
                }
        }
        DEBUG(print_dma_descriptors((*pj)->iop));

        DEBUG(printk("cryptocop_job_setup, DMA list setup successful\n"));

        return 0;
}

static int cryptocop_open(struct inode *inode, struct file *filp)
{
        int p = iminor(inode);

        if (p != CRYPTOCOP_MINOR) return -EINVAL;

        filp->private_data = NULL;
        return 0;
}


static int cryptocop_release(struct inode *inode, struct file *filp)
{
        struct cryptocop_private *dev = filp->private_data;
        struct cryptocop_private *dev_next;

        while (dev){
                dev_next = dev->next;
                if (dev->sid != CRYPTOCOP_SESSION_ID_NONE) {
                        (void)cryptocop_free_session(dev->sid);
                }
                kfree(dev);
                dev = dev_next;
        }

        return 0;
}


static int cryptocop_ioctl_close_session(struct inode *inode, struct file *filp,
                                         unsigned int cmd, unsigned long arg)
{
        struct cryptocop_private  *dev = filp->private_data;
        struct cryptocop_private  *prev_dev = NULL;
        struct strcop_session_op  *sess_op = (struct strcop_session_op *)arg;
        struct strcop_session_op  sop;
        int                       err;

        DEBUG(printk("cryptocop_ioctl_close_session\n"));

        if (!access_ok(VERIFY_READ, sess_op, sizeof(struct strcop_session_op)))
                return -EFAULT;
        err = copy_from_user(&sop, sess_op, sizeof(struct strcop_session_op));
        if (err) return -EFAULT;

        while (dev && (dev->sid != sop.ses_id)) {
                prev_dev = dev;
                dev = dev->next;
        }
        if (dev){
                if (prev_dev){
                        prev_dev->next = dev->next;
                } else {
                        filp->private_data = dev->next;
                }
                err = cryptocop_free_session(dev->sid);
                if (err) return -EFAULT;
        } else {
                DEBUG_API(printk("cryptocop_ioctl_close_session: session %lld not found\n", sop.ses_id));
                return -EINVAL;
        }
        return 0;
}


static void ioctl_process_job_callback(struct cryptocop_operation *op, void*cb_data)
{
        struct ioctl_job_cb_ctx *jc = (struct ioctl_job_cb_ctx *)cb_data;

        DEBUG(printk("ioctl_process_job_callback: op=0x%p, cb_data=0x%p\n", op, cb_data));

        jc->processed = 1;
        wake_up(&cryptocop_ioc_process_wq);
}


#define CRYPTOCOP_IOCTL_CIPHER_TID  (1)
#define CRYPTOCOP_IOCTL_DIGEST_TID  (2)
#define CRYPTOCOP_IOCTL_CSUM_TID    (3)

static size_t first_cfg_change_ix(struct strcop_crypto_op *crp_op)
{
        size_t ch_ix = 0;

        if (crp_op->do_cipher) ch_ix = crp_op->cipher_start;
        if (crp_op->do_digest && (crp_op->digest_start < ch_ix)) ch_ix = crp_op->digest_start;
        if (crp_op->do_csum && (crp_op->csum_start < ch_ix)) ch_ix = crp_op->csum_start;

        DEBUG(printk("first_cfg_change_ix: ix=%d\n", ch_ix));
        return ch_ix;
}


static size_t next_cfg_change_ix(struct strcop_crypto_op *crp_op, size_t ix)
{
        size_t ch_ix = INT_MAX;
        size_t tmp_ix = 0;

        if (crp_op->do_cipher && ((crp_op->cipher_start + crp_op->cipher_len) > ix)){
                if (crp_op->cipher_start > ix) {
                        ch_ix = crp_op->cipher_start;
                } else {
                        ch_ix = crp_op->cipher_start + crp_op->cipher_len;
                }
        }
        if (crp_op->do_digest && ((crp_op->digest_start + crp_op->digest_len) > ix)){
                if (crp_op->digest_start > ix) {
                        tmp_ix = crp_op->digest_start;
                } else {
                        tmp_ix = crp_op->digest_start + crp_op->digest_len;
                }
                if (tmp_ix < ch_ix) ch_ix = tmp_ix;
        }
        if (crp_op->do_csum && ((crp_op->csum_start + crp_op->csum_len) > ix)){
                if (crp_op->csum_start > ix) {
                        tmp_ix = crp_op->csum_start;
                } else {
                        tmp_ix = crp_op->csum_start + crp_op->csum_len;
                }
                if (tmp_ix < ch_ix) ch_ix = tmp_ix;
        }
        if (ch_ix == INT_MAX) ch_ix = ix;
        DEBUG(printk("next_cfg_change_ix prev ix=%d, next ix=%d\n", ix, ch_ix));
        return ch_ix;
}


/* Map map_length bytes from the pages starting on *pageix and *pageoffset to iovecs starting on *iovix.
 * Return -1 for ok, 0 for fail. */
static int map_pages_to_iovec(struct iovec *iov, int iovlen, int *iovix, struct page **pages, int nopages, int *pageix, int *pageoffset, int map_length )
{
        int tmplen;

        assert(iov != NULL);
        assert(iovix != NULL);
        assert(pages != NULL);
        assert(pageix != NULL);
        assert(pageoffset != NULL);

        DEBUG(printk("map_pages_to_iovec, map_length=%d, iovlen=%d, *iovix=%d, nopages=%d, *pageix=%d, *pageoffset=%d\n", map_length, iovlen, *iovix, nopages, *pageix, *pageoffset));

        while (map_length > 0){
                DEBUG(printk("map_pages_to_iovec, map_length=%d, iovlen=%d, *iovix=%d, nopages=%d, *pageix=%d, *pageoffset=%d\n", map_length, iovlen, *iovix, nopages, *pageix, *pageoffset));
                if (*iovix >= iovlen){
                        DEBUG_API(printk("map_page_to_iovec: *iovix=%d >= iovlen=%d\n", *iovix, iovlen));
                        return 0;
                }
                if (*pageix >= nopages){
                        DEBUG_API(printk("map_page_to_iovec: *pageix=%d >= nopages=%d\n", *pageix, nopages));
                        return 0;
                }
                iov[*iovix].iov_base = (unsigned char*)page_address(pages[*pageix]) + *pageoffset;
                tmplen = PAGE_SIZE - *pageoffset;
                if (tmplen < map_length){
                        (*pageoffset) = 0;
                        (*pageix)++;
                } else {
                        tmplen = map_length;
                        (*pageoffset) += map_length;
                }
                DEBUG(printk("mapping %d bytes from page %d (or %d) to iovec %d\n", tmplen, *pageix, *pageix-1, *iovix));
                iov[*iovix].iov_len = tmplen;
                map_length -= tmplen;
                (*iovix)++;
        }
        DEBUG(printk("map_page_to_iovec, exit, *iovix=%d\n", *iovix));
        return -1;
}



static int cryptocop_ioctl_process(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
{
        int                             i;
        struct cryptocop_private        *dev = filp->private_data;
        struct strcop_crypto_op         *crp_oper = (struct strcop_crypto_op *)arg;
        struct strcop_crypto_op         oper = {0};
        int                             err = 0;
        struct cryptocop_operation      *cop = NULL;

        struct ioctl_job_cb_ctx         *jc = NULL;

        struct page                     **inpages = NULL;
        struct page                     **outpages = NULL;
        int                             noinpages = 0;
        int                             nooutpages = 0;

        struct cryptocop_desc           descs[5]; /* Max 5 descriptors are needed, there are three transforms that
                                                   * can get connected/disconnected on different places in the indata. */
        struct cryptocop_desc_cfg       dcfgs[5*3];
        int                             desc_ix = 0;
        int                             dcfg_ix = 0;
        struct cryptocop_tfrm_cfg       ciph_tcfg = {0};
        struct cryptocop_tfrm_cfg       digest_tcfg = {0};
        struct cryptocop_tfrm_cfg       csum_tcfg = {0};

        unsigned char                   *digest_result = NULL;
        int                             digest_length = 0;
        int                             cblocklen = 0;
        unsigned char                   csum_result[CSUM_BLOCK_LENGTH];
        struct cryptocop_session        *sess;

        int    iovlen = 0;
        int    iovix = 0;
        int    pageix = 0;
        int    pageoffset = 0;

        size_t prev_ix = 0;
        size_t next_ix;

        int    cipher_active, digest_active, csum_active;
        int    end_digest, end_csum;
        int    digest_done = 0;
        int    cipher_done = 0;
        int    csum_done = 0;

        DEBUG(printk("cryptocop_ioctl_process\n"));

        if (!access_ok(VERIFY_WRITE, crp_oper, sizeof(struct strcop_crypto_op))){
                DEBUG_API(printk("cryptocop_ioctl_process: !access_ok crp_oper!\n"));
                return -EFAULT;
        }
        if (copy_from_user(&oper, crp_oper, sizeof(struct strcop_crypto_op))) {
                DEBUG_API(printk("cryptocop_ioctl_process: copy_from_user\n"));
                return -EFAULT;
        }
        DEBUG(print_strcop_crypto_op(&oper));

        while (dev && dev->sid != oper.ses_id) dev = dev->next;
        if (!dev){
                DEBUG_API(printk("cryptocop_ioctl_process: session %lld not found\n", oper.ses_id));
                return -EINVAL;
        }

        /* Check buffers. */
        if (((oper.indata + oper.inlen) < oper.indata) || ((oper.cipher_outdata + oper.cipher_outlen) < oper.cipher_outdata)){
                DEBUG_API(printk("cryptocop_ioctl_process: user buffers wrapped around, bad user!\n"));
                return -EINVAL;
        }

        if (!access_ok(VERIFY_WRITE, oper.cipher_outdata, oper.cipher_outlen)){
                DEBUG_API(printk("cryptocop_ioctl_process: !access_ok out data!\n"));
                return -EFAULT;
        }
        if (!access_ok(VERIFY_READ, oper.indata, oper.inlen)){
                DEBUG_API(printk("cryptocop_ioctl_process: !access_ok in data!\n"));
                return -EFAULT;
        }

        cop = kmalloc(sizeof(struct cryptocop_operation), GFP_KERNEL);
        if (!cop) {
                DEBUG_API(printk("cryptocop_ioctl_process: kmalloc\n"));
                return -ENOMEM;
        }
        jc = kmalloc(sizeof(struct ioctl_job_cb_ctx), GFP_KERNEL);
        if (!jc) {
                DEBUG_API(printk("cryptocop_ioctl_process: kmalloc\n"));
                err = -ENOMEM;
                goto error_cleanup;
        }
        jc->processed = 0;

        cop->cb_data = jc;
        cop->cb = ioctl_process_job_callback;
        cop->operation_status = 0;
        cop->use_dmalists = 0;
        cop->in_interrupt = 0;
        cop->fast_callback = 0;
        cop->tfrm_op.tfrm_cfg = NULL;
        cop->tfrm_op.desc = NULL;
        cop->tfrm_op.indata = NULL;
        cop->tfrm_op.incount = 0;
        cop->tfrm_op.inlen = 0;
        cop->tfrm_op.outdata = NULL;
        cop->tfrm_op.outcount = 0;
        cop->tfrm_op.outlen = 0;

        sess = get_session(oper.ses_id);
        if (!sess){
                DEBUG_API(printk("cryptocop_ioctl_process: bad session id.\n"));
                kfree(cop);
                kfree(jc);
                return -EINVAL;
        }

        if (oper.do_cipher) {
                unsigned int                    cipher_outlen = 0;
                struct cryptocop_transform_ctx  *tc = get_transform_ctx(sess, CRYPTOCOP_IOCTL_CIPHER_TID);
                if (!tc) {
                        DEBUG_API(printk("cryptocop_ioctl_process: no cipher transform in session.\n"));
                        err = -EINVAL;
                        goto error_cleanup;
                }
                ciph_tcfg.tid = CRYPTOCOP_IOCTL_CIPHER_TID;
                ciph_tcfg.inject_ix = 0;
                ciph_tcfg.flags = 0;
                if ((oper.cipher_start < 0) || (oper.cipher_len <= 0) || (oper.cipher_start > oper.inlen) || ((oper.cipher_start + oper.cipher_len) > oper.inlen)){
                        DEBUG_API(printk("cryptocop_ioctl_process: bad cipher length\n"));
                        kfree(cop);
                        kfree(jc);
                        return -EINVAL;
                }
                cblocklen = tc->init.alg == cryptocop_alg_aes ? AES_BLOCK_LENGTH : DES_BLOCK_LENGTH;
                if (oper.cipher_len % cblocklen) {
                        kfree(cop);
                        kfree(jc);
                        DEBUG_API(printk("cryptocop_ioctl_process: cipher inlength not multiple of block length.\n"));
                        return -EINVAL;
                }
                cipher_outlen = oper.cipher_len;
                if (tc->init.cipher_mode == cryptocop_cipher_mode_cbc){
                        if (oper.cipher_explicit) {
                                ciph_tcfg.flags |= CRYPTOCOP_EXPLICIT_IV;
                                memcpy(ciph_tcfg.iv, oper.cipher_iv, cblocklen);
                        } else {
                                cipher_outlen = oper.cipher_len - cblocklen;
                        }
                } else {
                        if (oper.cipher_explicit){
                                kfree(cop);
                                kfree(jc);
                                DEBUG_API(printk("cryptocop_ioctl_process: explicit_iv when not CBC mode\n"));
                                return -EINVAL;
                        }
                }
                if (oper.cipher_outlen != cipher_outlen) {
                        kfree(cop);
                        kfree(jc);
                        DEBUG_API(printk("cryptocop_ioctl_process: cipher_outlen incorrect, should be %d not %d.\n", cipher_outlen, oper.cipher_outlen));
                        return -EINVAL;
                }

                if (oper.decrypt){
                        ciph_tcfg.flags |= CRYPTOCOP_DECRYPT;
                } else {
                        ciph_tcfg.flags |= CRYPTOCOP_ENCRYPT;
                }
                ciph_tcfg.next = cop->tfrm_op.tfrm_cfg;
                cop->tfrm_op.tfrm_cfg = &ciph_tcfg;
        }
        if (oper.do_digest){
                struct cryptocop_transform_ctx *tc = get_transform_ctx(sess, CRYPTOCOP_IOCTL_DIGEST_TID);
                if (!tc) {
                        DEBUG_API(printk("cryptocop_ioctl_process: no digest transform in session.\n"));
                        err = -EINVAL;
                        goto error_cleanup;
                }
                digest_length = tc->init.alg == cryptocop_alg_md5 ? 16 : 20;
                digest_result = kmalloc(digest_length, GFP_KERNEL);
                if (!digest_result) {
                        DEBUG_API(printk("cryptocop_ioctl_process: kmalloc digest_result\n"));
                        err = -EINVAL;
                        goto error_cleanup;
                }
                DEBUG(memset(digest_result, 0xff, digest_length));

                digest_tcfg.tid = CRYPTOCOP_IOCTL_DIGEST_TID;
                digest_tcfg.inject_ix = 0;
                ciph_tcfg.inject_ix += digest_length;
                if ((oper.digest_start < 0) || (oper.digest_len <= 0) || (oper.digest_start > oper.inlen) || ((oper.digest_start + oper.digest_len) > oper.inlen)){
                        DEBUG_API(printk("cryptocop_ioctl_process: bad digest length\n"));
                        err = -EINVAL;
                        goto error_cleanup;
                }

                digest_tcfg.next = cop->tfrm_op.tfrm_cfg;
                cop->tfrm_op.tfrm_cfg = &digest_tcfg;
        }
        if (oper.do_csum){
                csum_tcfg.tid = CRYPTOCOP_IOCTL_CSUM_TID;
                csum_tcfg.inject_ix = digest_length;
                ciph_tcfg.inject_ix += 2;

                if ((oper.csum_start < 0) || (oper.csum_len <= 0) || (oper.csum_start > oper.inlen) || ((oper.csum_start + oper.csum_len) > oper.inlen)){
                        DEBUG_API(printk("cryptocop_ioctl_process: bad csum length\n"));
                        kfree(cop);
                        kfree(jc);
                        return -EINVAL;
                }

                csum_tcfg.next = cop->tfrm_op.tfrm_cfg;
                cop->tfrm_op.tfrm_cfg = &csum_tcfg;
        }

        prev_ix = first_cfg_change_ix(&oper);
        if (prev_ix > oper.inlen) {
                DEBUG_API(printk("cryptocop_ioctl_process: length mismatch\n"));
                nooutpages = noinpages = 0;
                err = -EINVAL;
                goto error_cleanup;
        }
        DEBUG(printk("cryptocop_ioctl_process: inlen=%d, cipher_outlen=%d\n", oper.inlen, oper.cipher_outlen));

        /* Map user pages for in and out data of the operation. */
        noinpages = (((unsigned long int)(oper.indata + prev_ix) & ~PAGE_MASK) + oper.inlen - 1 - prev_ix + ~PAGE_MASK) >> PAGE_SHIFT;
        DEBUG(printk("cryptocop_ioctl_process: noinpages=%d\n", noinpages));
        inpages = kmalloc(noinpages * sizeof(struct page*), GFP_KERNEL);
        if (!inpages){
                DEBUG_API(printk("cryptocop_ioctl_process: kmalloc inpages\n"));
                nooutpages = noinpages = 0;
                err = -ENOMEM;
                goto error_cleanup;
        }
        if (oper.do_cipher){
                nooutpages = (((unsigned long int)oper.cipher_outdata & ~PAGE_MASK) + oper.cipher_outlen - 1 + ~PAGE_MASK) >> PAGE_SHIFT;
                DEBUG(printk("cryptocop_ioctl_process: nooutpages=%d\n", nooutpages));
                outpages = kmalloc(nooutpages * sizeof(struct page*), GFP_KERNEL);
                if (!outpages){
                        DEBUG_API(printk("cryptocop_ioctl_process: kmalloc outpages\n"));
                        nooutpages = noinpages = 0;
                        err = -ENOMEM;
                        goto error_cleanup;
                }
        }

        /* Acquire the mm page semaphore. */
        down_read(&current->mm->mmap_sem);

        err = get_user_pages(current,
                             current->mm,
                             (unsigned long int)(oper.indata + prev_ix),
                             noinpages,
                             0,  /* read access only for in data */
                             0, /* no force */
                             inpages,
                             NULL);

        if (err < 0) {
                up_read(&current->mm->mmap_sem);
                nooutpages = noinpages = 0;
                DEBUG_API(printk("cryptocop_ioctl_process: get_user_pages indata\n"));
                goto error_cleanup;
        }
        noinpages = err;
        if (oper.do_cipher){
                err = get_user_pages(current,
                                     current->mm,
                                     (unsigned long int)oper.cipher_outdata,
                                     nooutpages,
                                     1, /* write access for out data */
                                     0, /* no force */
                                     outpages,
                                     NULL);
                up_read(&current->mm->mmap_sem);
                if (err < 0) {
                        nooutpages = 0;
                        DEBUG_API(printk("cryptocop_ioctl_process: get_user_pages outdata\n"));
                        goto error_cleanup;
                }
                nooutpages = err;
        } else {
                up_read(&current->mm->mmap_sem);
        }

        /* Add 6 to nooutpages to make room for possibly inserted buffers for storing digest and
         * csum output and splits when units are (dis-)connected. */
        cop->tfrm_op.indata = kmalloc((noinpages) * sizeof(struct iovec), GFP_KERNEL);
        cop->tfrm_op.outdata = kmalloc((6 + nooutpages) * sizeof(struct iovec), GFP_KERNEL);
        if (!cop->tfrm_op.indata || !cop->tfrm_op.outdata) {
                DEBUG_API(printk("cryptocop_ioctl_process: kmalloc iovecs\n"));
                err = -ENOMEM;
                goto error_cleanup;
        }

        cop->tfrm_op.inlen = oper.inlen - prev_ix;
        cop->tfrm_op.outlen = 0;
        if (oper.do_cipher) cop->tfrm_op.outlen += oper.cipher_outlen;
        if (oper.do_digest) cop->tfrm_op.outlen += digest_length;
        if (oper.do_csum) cop->tfrm_op.outlen += 2;

        /* Setup the in iovecs. */
        cop->tfrm_op.incount = noinpages;
        if (noinpages > 1){
                size_t tmplen = cop->tfrm_op.inlen;

                cop->tfrm_op.indata[0].iov_len = PAGE_SIZE - ((unsigned long int)(oper.indata + prev_ix) & ~PAGE_MASK);
                cop->tfrm_op.indata[0].iov_base = (unsigned char*)page_address(inpages[0]) + ((unsigned long int)(oper.indata + prev_ix) & ~PAGE_MASK);
                tmplen -= cop->tfrm_op.indata[0].iov_len;
                for (i = 1; i<noinpages; i++){
                        cop->tfrm_op.indata[i].iov_len = tmplen < PAGE_SIZE ? tmplen : PAGE_SIZE;
                        cop->tfrm_op.indata[i].iov_base = (unsigned char*)page_address(inpages[i]);
                        tmplen -= PAGE_SIZE;
                }
        } else {
                cop->tfrm_op.indata[0].iov_len = oper.inlen - prev_ix;
                cop->tfrm_op.indata[0].iov_base = (unsigned char*)page_address(inpages[0]) + ((unsigned long int)(oper.indata + prev_ix) & ~PAGE_MASK);
        }

        iovlen = nooutpages + 6;
        pageoffset = oper.do_cipher ? ((unsigned long int)oper.cipher_outdata & ~PAGE_MASK) : 0;

        next_ix = next_cfg_change_ix(&oper, prev_ix);
        if (prev_ix == next_ix){
                DEBUG_API(printk("cryptocop_ioctl_process: length configuration broken.\n"));
                err = -EINVAL;  /* This should be impossible barring bugs. */
                goto error_cleanup;
        }
        while (prev_ix != next_ix){
                end_digest = end_csum = cipher_active = digest_active = csum_active = 0;
                descs[desc_ix].cfg = NULL;
                descs[desc_ix].length = next_ix - prev_ix;

                if (oper.do_cipher && (oper.cipher_start < next_ix) && (prev_ix < (oper.cipher_start + oper.cipher_len))) {
                        dcfgs[dcfg_ix].tid = CRYPTOCOP_IOCTL_CIPHER_TID;
                        dcfgs[dcfg_ix].src = cryptocop_source_dma;
                        cipher_active = 1;

                        if (next_ix == (oper.cipher_start + oper.cipher_len)){
                                cipher_done = 1;
                                dcfgs[dcfg_ix].last = 1;
                        } else {
                                dcfgs[dcfg_ix].last = 0;
                        }
                        dcfgs[dcfg_ix].next = descs[desc_ix].cfg;
                        descs[desc_ix].cfg = &dcfgs[dcfg_ix];
                        ++dcfg_ix;
                }
                if (oper.do_digest && (oper.digest_start < next_ix) && (prev_ix < (oper.digest_start + oper.digest_len))) {
                        digest_active = 1;
                        dcfgs[dcfg_ix].tid = CRYPTOCOP_IOCTL_DIGEST_TID;
                        dcfgs[dcfg_ix].src = cryptocop_source_dma;
                        if (next_ix == (oper.digest_start + oper.digest_len)){
                                assert(!digest_done);
                                digest_done = 1;
                                dcfgs[dcfg_ix].last = 1;
                        } else {
                                dcfgs[dcfg_ix].last = 0;
                        }
                        dcfgs[dcfg_ix].next = descs[desc_ix].cfg;
                        descs[desc_ix].cfg = &dcfgs[dcfg_ix];
                        ++dcfg_ix;
                }
                if (oper.do_csum && (oper.csum_start < next_ix) && (prev_ix < (oper.csum_start + oper.csum_len))){
                        csum_active = 1;
                        dcfgs[dcfg_ix].tid = CRYPTOCOP_IOCTL_CSUM_TID;
                        dcfgs[dcfg_ix].src = cryptocop_source_dma;
                        if (next_ix == (oper.csum_start + oper.csum_len)){
                                csum_done = 1;
                                dcfgs[dcfg_ix].last = 1;
                        } else {
                                dcfgs[dcfg_ix].last = 0;
                        }
                        dcfgs[dcfg_ix].next = descs[desc_ix].cfg;
                        descs[desc_ix].cfg = &dcfgs[dcfg_ix];
                        ++dcfg_ix;
                }
                if (!descs[desc_ix].cfg){
                        DEBUG_API(printk("cryptocop_ioctl_process: data segment %d (%d to %d) had no active transforms\n", desc_ix, prev_ix, next_ix));
                        err = -EINVAL;
                        goto error_cleanup;
                }
                descs[desc_ix].next = &(descs[desc_ix]) + 1;
                ++desc_ix;
                prev_ix = next_ix;
                next_ix = next_cfg_change_ix(&oper, prev_ix);
        }
        if (desc_ix > 0){
                descs[desc_ix-1].next = NULL;
        } else {
                descs[0].next = NULL;
        }
        if (oper.do_digest) {
                DEBUG(printk("cryptocop_ioctl_process: mapping %d byte digest output to iovec %d\n", digest_length, iovix));
                /* Add outdata iovec, length == <length of type of digest> */
                cop->tfrm_op.outdata[iovix].iov_base = digest_result;
                cop->tfrm_op.outdata[iovix].iov_len = digest_length;
                ++iovix;
        }
        if (oper.do_csum) {
                /* Add outdata iovec, length == 2, the length of csum. */
                DEBUG(printk("cryptocop_ioctl_process: mapping 2 byte csum output to iovec %d\n", iovix));
                /* Add outdata iovec, length == <length of type of digest> */
                cop->tfrm_op.outdata[iovix].iov_base = csum_result;
                cop->tfrm_op.outdata[iovix].iov_len = 2;
                ++iovix;
        }
        if (oper.do_cipher) {
                if (!map_pages_to_iovec(cop->tfrm_op.outdata, iovlen, &iovix, outpages, nooutpages, &pageix, &pageoffset, oper.cipher_outlen)){
                        DEBUG_API(printk("cryptocop_ioctl_process: failed to map pages to iovec.\n"));
                        err = -ENOSYS; /* This should be impossible barring bugs. */
                        goto error_cleanup;
                }
        }
        DEBUG(printk("cryptocop_ioctl_process: setting cop->tfrm_op.outcount %d\n", iovix));
        cop->tfrm_op.outcount = iovix;
        assert(iovix <= (nooutpages + 6));

        cop->sid = oper.ses_id;
        cop->tfrm_op.desc = &descs[0];

        DEBUG(printk("cryptocop_ioctl_process: inserting job, cb_data=0x%p\n", cop->cb_data));

        if ((err = cryptocop_job_queue_insert_user_job(cop)) != 0) {
                DEBUG_API(printk("cryptocop_ioctl_process: insert job %d\n", err));
                err = -EINVAL;
                goto error_cleanup;
        }

        DEBUG(printk("cryptocop_ioctl_process: begin wait for result\n"));

        wait_event(cryptocop_ioc_process_wq, (jc->processed != 0));
        DEBUG(printk("cryptocop_ioctl_process: end wait for result\n"));
        if (!jc->processed){
                printk(KERN_WARNING "cryptocop_ioctl_process: job not processed at completion\n");
                err = -EIO;
                goto error_cleanup;
        }

        /* Job process done.  Cipher output should already be correct in job so no post processing of outdata. */
        DEBUG(printk("cryptocop_ioctl_process: operation_status = %d\n", cop->operation_status));
        if (cop->operation_status == 0){
                if (oper.do_digest){
                        DEBUG(printk("cryptocop_ioctl_process: copy %d bytes digest to user\n", digest_length));
                        err = copy_to_user((unsigned char*)crp_oper + offsetof(struct strcop_crypto_op, digest), digest_result, digest_length);
                        if (0 != err){
                                DEBUG_API(printk("cryptocop_ioctl_process: copy_to_user, digest length %d, err %d\n", digest_length, err));
                                err = -EFAULT;
                                goto error_cleanup;
                        }
                }
                if (oper.do_csum){
                        DEBUG(printk("cryptocop_ioctl_process: copy 2 bytes checksum to user\n"));
                        err = copy_to_user((unsigned char*)crp_oper + offsetof(struct strcop_crypto_op, csum), csum_result, 2);
                        if (0 != err){
                                DEBUG_API(printk("cryptocop_ioctl_process: copy_to_user, csum, err %d\n", err));
                                err = -EFAULT;
                                goto error_cleanup;
                        }
                }
                err = 0;
        } else {
                DEBUG(printk("cryptocop_ioctl_process: returning err = operation_status = %d\n", cop->operation_status));
                err = cop->operation_status;
        }

 error_cleanup:
        /* Release page caches. */
        for (i = 0; i < noinpages; i++){
                put_page(inpages[i]);
        }
        for (i = 0; i < nooutpages; i++){
                int spdl_err;
                /* Mark output pages dirty. */
                spdl_err = set_page_dirty_lock(outpages[i]);
                DEBUG(if (spdl_err < 0)printk("cryptocop_ioctl_process: set_page_dirty_lock returned %d\n", spdl_err));
        }
        for (i = 0; i < nooutpages; i++){
                put_page(outpages[i]);
        }

        kfree(digest_result);
        kfree(inpages);
        kfree(outpages);
        if (cop){
                kfree(cop->tfrm_op.indata);
                kfree(cop->tfrm_op.outdata);
                kfree(cop);
        }
        kfree(jc);

        DEBUG(print_lock_status());

        return err;
}


static int cryptocop_ioctl_create_session(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
{
        cryptocop_session_id             sid;
        int                              err;
        struct cryptocop_private         *dev;
        struct strcop_session_op         *sess_op = (struct strcop_session_op *)arg;
        struct strcop_session_op         sop;
        struct cryptocop_transform_init  *tis = NULL;
        struct cryptocop_transform_init  ti_cipher = {0};
        struct cryptocop_transform_init  ti_digest = {0};
        struct cryptocop_transform_init  ti_csum = {0};

        if (!access_ok(VERIFY_WRITE, sess_op, sizeof(struct strcop_session_op)))
                return -EFAULT;
        err = copy_from_user(&sop, sess_op, sizeof(struct strcop_session_op));
        if (err) return -EFAULT;
        if (sop.cipher != cryptocop_cipher_none) {
                if (!access_ok(VERIFY_READ, sop.key, sop.keylen)) return -EFAULT;
        }
        DEBUG(printk("cryptocop_ioctl_create_session, sess_op:\n"));

        DEBUG(printk("\tcipher:%d\n"
                     "\tcipher_mode:%d\n"
                     "\tdigest:%d\n"
                     "\tcsum:%d\n",
                     (int)sop.cipher,
                     (int)sop.cmode,
                     (int)sop.digest,
                     (int)sop.csum));