LXR linux/include/scsi/scsi

   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#include <linux/blkdev.h>
  11
  12struct Scsi_Host;
  13struct scsi_device;
  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        int timeout_per_command;
  80
  81        unsigned short cmd_len;
  82        enum dma_data_direction sc_data_direction;
  83
  84        /* These elements define the operation we are about to perform */
  85        unsigned char *cmnd;
  86
  87        struct timer_list eh_timeout;   /* Used to time out the command. */
  88
  89        /* These elements define the operation we ultimately want to perform */
  90        struct scsi_data_buffer sdb;
  91        unsigned underflow;     /* Return error if less than
  92                                   this amount is transferred */
  93
  94        unsigned transfersize;  /* How much we are guaranteed to
  95                                   transfer with each SCSI transfer
  96                                   (ie, between disconnect / 
  97                                   reconnects.   Probably == sector
  98                                   size */
  99
 100        struct request *request;        /* The command we are
 101                                           working on */
 102
 103#define SCSI_SENSE_BUFFERSIZE   96
 104        unsigned char *sense_buffer;
 105                                /* obtained by REQUEST SENSE when
 106                                 * CHECK CONDITION is received on original
 107                                 * command (auto-sense) */
 108
 109        /* Low-level done function - can be used by low-level driver to point
 110         *        to completion function.  Not used by mid/upper level code. */
 111        void (*scsi_done) (struct scsi_cmnd *);
 112
 113        /*
 114         * The following fields can be written to by the host specific code. 
 115         * Everything else should be left alone. 
 116         */
 117        struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 118
 119        unsigned char *host_scribble;   /* The host adapter is allowed to
 120                                         * call scsi_malloc and get some memory
 121                                         * and hang it here.  The host adapter
 122                                         * is also expected to call scsi_free
 123                                         * to release this memory.  (The memory
 124                                         * obtained by scsi_malloc is guaranteed
 125                                         * to be at an address < 16Mb). */
 126
 127        int result;             /* Status code from lower level driver */
 128
 129        unsigned char tag;      /* SCSI-II queued command tag */
 130};
 131
 132extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 133extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
 134extern void scsi_put_command(struct scsi_cmnd *);
 135extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
 136                               struct device *);
 137extern void scsi_finish_command(struct scsi_cmnd *cmd);
 138extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
 139
 140extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 141                                 size_t *offset, size_t *len);
 142extern void scsi_kunmap_atomic_sg(void *virt);
 143
 144extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
 145extern void scsi_release_buffers(struct scsi_cmnd *cmd);
 146
 147extern int scsi_dma_map(struct scsi_cmnd *cmd);
 148extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 149
 150struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
 151void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
 152
 153static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 154{
 155        return cmd->sdb.table.nents;
 156}
 157
 158static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 159{
 160        return cmd->sdb.table.sgl;
 161}
 162
 163static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 164{
 165        return cmd->sdb.length;
 166}
 167
 168static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 169{
 170        cmd->sdb.resid = resid;
 171}
 172
 173static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 174{
 175        return cmd->sdb.resid;
 176}
 177
 178#define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 179        for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 180
 181static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
 182{
 183        return blk_bidi_rq(cmd->request) &&
 184                (cmd->request->next_rq->special != NULL);
 185}
 186
 187static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
 188{
 189        return scsi_bidi_cmnd(cmd) ?
 190                cmd->request->next_rq->special : &cmd->sdb;
 191}
 192
 193static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
 194{
 195        return &cmd->sdb;
 196}
 197
 198static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 199                                           void *buf, int buflen)
 200{
 201        return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 202                                   buf, buflen);
 203}
 204
 205static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 206                                         void *buf, int buflen)
 207{
 208        return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 209                                 buf, buflen);
 210}
 211
 212#endif /* _SCSI_SCSI_CMND_H */
 213