linux/include/scsi/scsi_cmnd.h
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   1#ifndef _SCSI_SCSI_CMND_H
   2#define _SCSI_SCSI_CMND_H
   3
   4#include <linux/dma-mapping.h>
   5#include <linux/blkdev.h>
   6#include <linux/list.h>
   7#include <linux/types.h>
   8#include <linux/timer.h>
   9#include <linux/scatterlist.h>
  10
  11struct Scsi_Host;
  12struct scsi_device;
  13struct scsi_driver;
  14
  15/*
  16 * MAX_COMMAND_SIZE is:
  17 * The longest fixed-length SCSI CDB as per the SCSI standard.
  18 * fixed-length means: commands that their size can be determined
  19 * by their opcode and the CDB does not carry a length specifier, (unlike
  20 * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
  21 * true and the SCSI standard also defines extended commands and
  22 * vendor specific commands that can be bigger than 16 bytes. The kernel
  23 * will support these using the same infrastructure used for VARLEN CDB's.
  24 * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
  25 * supports without specifying a cmd_len by ULD's
  26 */
  27#define MAX_COMMAND_SIZE 16
  28#if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
  29# error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
  30#endif
  31
  32struct scsi_data_buffer {
  33        struct sg_table table;
  34        unsigned length;
  35        int resid;
  36};
  37
  38/* embedded in scsi_cmnd */
  39struct scsi_pointer {
  40        char *ptr;              /* data pointer */
  41        int this_residual;      /* left in this buffer */
  42        struct scatterlist *buffer;     /* which buffer */
  43        int buffers_residual;   /* how many buffers left */
  44
  45        dma_addr_t dma_handle;
  46
  47        volatile int Status;
  48        volatile int Message;
  49        volatile int have_data_in;
  50        volatile int sent_command;
  51        volatile int phase;
  52};
  53
  54struct scsi_cmnd {
  55        struct scsi_device *device;
  56        struct list_head list;  /* scsi_cmnd participates in queue lists */
  57        struct list_head eh_entry; /* entry for the host eh_cmd_q */
  58        int eh_eflags;          /* Used by error handlr */
  59
  60        /*
  61         * A SCSI Command is assigned a nonzero serial_number before passed
  62         * to the driver's queue command function.  The serial_number is
  63         * cleared when scsi_done is entered indicating that the command
  64         * has been completed.  It is a bug for LLDDs to use this number
  65         * for purposes other than printk (and even that is only useful
  66         * for debugging).
  67         */
  68        unsigned long serial_number;
  69
  70        /*
  71         * This is set to jiffies as it was when the command was first
  72         * allocated.  It is used to time how long the command has
  73         * been outstanding
  74         */
  75        unsigned long jiffies_at_alloc;
  76
  77        int retries;
  78        int allowed;
  79
  80        unsigned char prot_op;
  81        unsigned char prot_type;
  82
  83        unsigned short cmd_len;
  84        enum dma_data_direction sc_data_direction;
  85
  86        /* These elements define the operation we are about to perform */
  87        unsigned char *cmnd;
  88
  89
  90        /* These elements define the operation we ultimately want to perform */
  91        struct scsi_data_buffer sdb;
  92        struct scsi_data_buffer *prot_sdb;
  93
  94        unsigned underflow;     /* Return error if less than
  95                                   this amount is transferred */
  96
  97        unsigned transfersize;  /* How much we are guaranteed to
  98                                   transfer with each SCSI transfer
  99                                   (ie, between disconnect / 
 100                                   reconnects.   Probably == sector
 101                                   size */
 102
 103        struct request *request;        /* The command we are
 104                                           working on */
 105
 106#define SCSI_SENSE_BUFFERSIZE   96
 107        unsigned char *sense_buffer;
 108                                /* obtained by REQUEST SENSE when
 109                                 * CHECK CONDITION is received on original
 110                                 * command (auto-sense) */
 111
 112        /* Low-level done function - can be used by low-level driver to point
 113         *        to completion function.  Not used by mid/upper level code. */
 114        void (*scsi_done) (struct scsi_cmnd *);
 115
 116        /*
 117         * The following fields can be written to by the host specific code. 
 118         * Everything else should be left alone. 
 119         */
 120        struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 121
 122        unsigned char *host_scribble;   /* The host adapter is allowed to
 123                                         * call scsi_malloc and get some memory
 124                                         * and hang it here.  The host adapter
 125                                         * is also expected to call scsi_free
 126                                         * to release this memory.  (The memory
 127                                         * obtained by scsi_malloc is guaranteed
 128                                         * to be at an address < 16Mb). */
 129
 130        int result;             /* Status code from lower level driver */
 131
 132        unsigned char tag;      /* SCSI-II queued command tag */
 133};
 134
 135static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
 136{
 137        struct scsi_driver **sdp;
 138
 139        if (!cmd->request->rq_disk)
 140                return NULL;
 141
 142        sdp = (struct scsi_driver **)cmd->request->rq_disk->private_data;
 143        if (!sdp)
 144                return NULL;
 145
 146        return *sdp;
 147}
 148
 149extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 150extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
 151extern void scsi_put_command(struct scsi_cmnd *);
 152extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
 153                               struct device *);
 154extern void scsi_finish_command(struct scsi_cmnd *cmd);
 155
 156extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 157                                 size_t *offset, size_t *len);
 158extern void scsi_kunmap_atomic_sg(void *virt);
 159
 160extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
 161extern void scsi_release_buffers(struct scsi_cmnd *cmd);
 162
 163extern int scsi_dma_map(struct scsi_cmnd *cmd);
 164extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 165
 166struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
 167void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
 168
 169static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 170{
 171        return cmd->sdb.table.nents;
 172}
 173
 174static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 175{
 176        return cmd->sdb.table.sgl;
 177}
 178
 179static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 180{
 181        return cmd->sdb.length;
 182}
 183
 184static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 185{
 186        cmd->sdb.resid = resid;
 187}
 188
 189static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 190{
 191        return cmd->sdb.resid;
 192}
 193
 194#define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 195        for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 196
 197static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
 198{
 199        return blk_bidi_rq(cmd->request) &&
 200                (cmd->request->next_rq->special != NULL);
 201}
 202
 203static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
 204{
 205        return scsi_bidi_cmnd(cmd) ?
 206                cmd->request->next_rq->special : &cmd->sdb;
 207}
 208
 209static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
 210{
 211        return &cmd->sdb;
 212}
 213
 214static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 215                                           void *buf, int buflen)
 216{
 217        return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 218                                   buf, buflen);
 219}
 220
 221static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 222                                         void *buf, int buflen)
 223{
 224        return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 225                                 buf, buflen);
 226}
 227
 228/*
 229 * The operations below are hints that tell the controller driver how
 230 * to handle I/Os with DIF or similar types of protection information.
 231 */
 232enum scsi_prot_operations {
 233        /* Normal I/O */
 234        SCSI_PROT_NORMAL = 0,
 235
 236        /* OS-HBA: Protected, HBA-Target: Unprotected */
 237        SCSI_PROT_READ_INSERT,
 238        SCSI_PROT_WRITE_STRIP,
 239
 240        /* OS-HBA: Unprotected, HBA-Target: Protected */
 241        SCSI_PROT_READ_STRIP,
 242        SCSI_PROT_WRITE_INSERT,
 243
 244        /* OS-HBA: Protected, HBA-Target: Protected */
 245        SCSI_PROT_READ_PASS,
 246        SCSI_PROT_WRITE_PASS,
 247};
 248
 249static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 250{
 251        scmd->prot_op = op;
 252}
 253
 254static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 255{
 256        return scmd->prot_op;
 257}
 258
 259/*
 260 * The controller usually does not know anything about the target it
 261 * is communicating with.  However, when DIX is enabled the controller
 262 * must be know target type so it can verify the protection
 263 * information passed along with the I/O.
 264 */
 265enum scsi_prot_target_type {
 266        SCSI_PROT_DIF_TYPE0 = 0,
 267        SCSI_PROT_DIF_TYPE1,
 268        SCSI_PROT_DIF_TYPE2,
 269        SCSI_PROT_DIF_TYPE3,
 270};
 271
 272static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 273{
 274        scmd->prot_type = type;
 275}
 276
 277static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 278{
 279        return scmd->prot_type;
 280}
 281
 282static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 283{
 284        return blk_rq_pos(scmd->request);
 285}
 286
 287static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 288{
 289        return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 290}
 291
 292static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 293{
 294        return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 295}
 296
 297static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 298{
 299        return cmd->prot_sdb;
 300}
 301
 302#define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 303        for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 304
 305static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
 306{
 307        cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
 308}
 309
 310static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 311{
 312        cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 313}
 314
 315static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 316{
 317        cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
 318}
 319
 320#endif /* _SCSI_SCSI_CMND_H */
 321
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