include/scsi/scsi_cmnd.h

   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
  11 struct Scsi_Host;
  12 struct scsi_device;
  13
  14 struct scsi_data_buffer {
  15         struct sg_table table;
  16         unsigned length;
  17         int resid;
  18 };
  19
  20 /* embedded in scsi_cmnd */
  21 struct scsi_pointer {
  22         char *ptr;              /* data pointer */
  23         int this_residual;      /* left in this buffer */
  24         struct scatterlist *buffer;     /* which buffer */
  25         int buffers_residual;   /* how many buffers left */
  26
  27         dma_addr_t dma_handle;
  28
  29         volatile int Status;
  30         volatile int Message;
  31         volatile int have_data_in;
  32         volatile int sent_command;
  33         volatile int phase;
  34 };
  35
  36 struct scsi_cmnd {
  37         struct scsi_device *device;
  38         struct list_head list;  /* scsi_cmnd participates in queue lists */
  39         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  40         int eh_eflags;          /* Used by error handlr */
  41
  42         /*
  43          * A SCSI Command is assigned a nonzero serial_number before passed
  44          * to the driver's queue command function.  The serial_number is
  45          * cleared when scsi_done is entered indicating that the command
  46          * has been completed.  It is a bug for LLDDs to use this number
  47          * for purposes other than printk (and even that is only useful
  48          * for debugging).
  49          */
  50         unsigned long serial_number;
  51
  52         /*
  53          * This is set to jiffies as it was when the command was first
  54          * allocated.  It is used to time how long the command has
  55          * been outstanding
  56          */
  57         unsigned long jiffies_at_alloc;
  58
  59         int retries;
  60         int allowed;
  61         int timeout_per_command;
  62
  63         unsigned char cmd_len;
  64         enum dma_data_direction sc_data_direction;
  65
  66         /* These elements define the operation we are about to perform */
  67 #define MAX_COMMAND_SIZE        16
  68         unsigned char cmnd[MAX_COMMAND_SIZE];
  69
  70         struct timer_list eh_timeout;   /* Used to time out the command. */
  71
  72         /* These elements define the operation we ultimately want to perform */
  73         struct scsi_data_buffer sdb;
  74         unsigned underflow;     /* Return error if less than
  75                                    this amount is transferred */
  76
  77         unsigned transfersize;  /* How much we are guaranteed to
  78                                    transfer with each SCSI transfer
  79                                    (ie, between disconnect /
  80                                    reconnects.   Probably == sector
  81                                    size */
  82
  83         struct request *request;        /* The command we are
  84                                            working on */
  85
  86 #define SCSI_SENSE_BUFFERSIZE   96
  87         unsigned char *sense_buffer;
  88                                 /* obtained by REQUEST SENSE when
  89                                  * CHECK CONDITION is received on original
  90                                  * command (auto-sense) */
  91
  92         /* Low-level done function - can be used by low-level driver to point
  93          *        to completion function.  Not used by mid/upper level code. */
  94         void (*scsi_done) (struct scsi_cmnd *);
  95
  96         /*
  97          * The following fields can be written to by the host specific code.
  98          * Everything else should be left alone.
  99          */
 100         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 101
 102         unsigned char *host_scribble;   /* The host adapter is allowed to
 103                                          * call scsi_malloc and get some memory
 104                                          * and hang it here.  The host adapter
 105                                          * is also expected to call scsi_free
 106                                          * to release this memory.  (The memory
 107                                          * obtained by scsi_malloc is guaranteed
 108                                          * to be at an address < 16Mb). */
 109
 110         int result;             /* Status code from lower level driver */
 111
 112         unsigned char tag;      /* SCSI-II queued command tag */
 113 };
 114
 115 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 116 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
 117 extern void scsi_put_command(struct scsi_cmnd *);
 118 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
 119                                struct device *);
 120 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 121 extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
 122
 123 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 124                                  size_t *offset, size_t *len);
 125 extern void scsi_kunmap_atomic_sg(void *virt);
 126
 127 extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
 128 extern void scsi_release_buffers(struct scsi_cmnd *cmd);
 129
 130 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 131 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 132
 133 struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
 134 void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
 135
 136 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 137 {
 138         return cmd->sdb.table.nents;
 139 }
 140
 141 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 142 {
 143         return cmd->sdb.table.sgl;
 144 }
 145
 146 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 147 {
 148         return cmd->sdb.length;
 149 }
 150
 151 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 152 {
 153         cmd->sdb.resid = resid;
 154 }
 155
 156 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 157 {
 158         return cmd->sdb.resid;
 159 }
 160
 161 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 162         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 163
 164 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
 165 {
 166         return blk_bidi_rq(cmd->request) &&
 167                 (cmd->request->next_rq->special != NULL);
 168 }
 169
 170 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
 171 {
 172         return scsi_bidi_cmnd(cmd) ?
 173                 cmd->request->next_rq->special : &cmd->sdb;
 174 }
 175
 176 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
 177 {
 178         return &cmd->sdb;
 179 }
 180
 181 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 182                                            void *buf, int buflen)
 183 {
 184         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 185                                    buf, buflen);
 186 }
 187
 188 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 189                                          void *buf, int buflen)
 190 {
 191         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 192                                  buf, buflen);
 193 }
 194
 195 #endif /* _SCSI_SCSI_CMND_H */