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/list.h>
   6 #include <linux/types.h>
   7 #include <linux/timer.h>
   8 #include <linux/scatterlist.h>
   9
  10 struct request;
  11 struct Scsi_Host;
  12 struct scsi_device;
  13
  14
  15 /* embedded in scsi_cmnd */
  16 struct scsi_pointer {
  17         char *ptr;              /* data pointer */
  18         int this_residual;      /* left in this buffer */
  19         struct scatterlist *buffer;     /* which buffer */
  20         int buffers_residual;   /* how many buffers left */
  21
  22         dma_addr_t dma_handle;
  23
  24         volatile int Status;
  25         volatile int Message;
  26         volatile int have_data_in;
  27         volatile int sent_command;
  28         volatile int phase;
  29 };
  30
  31 struct scsi_cmnd {
  32         struct scsi_device *device;
  33         struct list_head list;  /* scsi_cmnd participates in queue lists */
  34         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  35         int eh_eflags;          /* Used by error handlr */
  36
  37         /*
  38          * A SCSI Command is assigned a nonzero serial_number before passed
  39          * to the driver's queue command function.  The serial_number is
  40          * cleared when scsi_done is entered indicating that the command
  41          * has been completed.  It is a bug for LLDDs to use this number
  42          * for purposes other than printk (and even that is only useful
  43          * for debugging).
  44          */
  45         unsigned long serial_number;
  46
  47         /*
  48          * This is set to jiffies as it was when the command was first
  49          * allocated.  It is used to time how long the command has
  50          * been outstanding
  51          */
  52         unsigned long jiffies_at_alloc;
  53
  54         int retries;
  55         int allowed;
  56         int timeout_per_command;
  57
  58         unsigned char cmd_len;
  59         enum dma_data_direction sc_data_direction;
  60
  61         /* These elements define the operation we are about to perform */
  62 #define MAX_COMMAND_SIZE        16
  63         unsigned char cmnd[MAX_COMMAND_SIZE];
  64         unsigned request_bufflen;       /* Actual request size */
  65
  66         struct timer_list eh_timeout;   /* Used to time out the command. */
  67         void *request_buffer;           /* Actual requested buffer */
  68
  69         /* These elements define the operation we ultimately want to perform */
  70         struct sg_table sg_table;
  71         unsigned short use_sg;  /* Number of pieces of scatter-gather */
  72
  73         unsigned underflow;     /* Return error if less than
  74                                    this amount is transferred */
  75
  76         unsigned transfersize;  /* How much we are guaranteed to
  77                                    transfer with each SCSI transfer
  78                                    (ie, between disconnect /
  79                                    reconnects.   Probably == sector
  80                                    size */
  81
  82         int resid;              /* Number of bytes requested to be
  83                                    transferred less actual number
  84                                    transferred (0 if not supported) */
  85
  86         struct request *request;        /* The command we are
  87                                            working on */
  88
  89 #define SCSI_SENSE_BUFFERSIZE   96
  90         unsigned char *sense_buffer;
  91                                 /* obtained by REQUEST SENSE when
  92                                  * CHECK CONDITION is received on original
  93                                  * command (auto-sense) */
  94
  95         /* Low-level done function - can be used by low-level driver to point
  96          *        to completion function.  Not used by mid/upper level code. */
  97         void (*scsi_done) (struct scsi_cmnd *);
  98
  99         /*
 100          * The following fields can be written to by the host specific code.
 101          * Everything else should be left alone.
 102          */
 103         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 104
 105         unsigned char *host_scribble;   /* The host adapter is allowed to
 106                                          * call scsi_malloc and get some memory
 107                                          * and hang it here.  The host adapter
 108                                          * is also expected to call scsi_free
 109                                          * to release this memory.  (The memory
 110                                          * obtained by scsi_malloc is guaranteed
 111                                          * to be at an address < 16Mb). */
 112
 113         int result;             /* Status code from lower level driver */
 114
 115         unsigned char tag;      /* SCSI-II queued command tag */
 116 };
 117
 118 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 119 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
 120 extern void scsi_put_command(struct scsi_cmnd *);
 121 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
 122                                struct device *);
 123 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 124 extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
 125
 126 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 127                                  size_t *offset, size_t *len);
 128 extern void scsi_kunmap_atomic_sg(void *virt);
 129
 130 extern int scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t);
 131 extern void scsi_free_sgtable(struct scsi_cmnd *);
 132
 133 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 134 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 135
 136 #define scsi_sg_count(cmd) ((cmd)->use_sg)
 137 #define scsi_sglist(cmd) ((cmd)->sg_table.sgl)
 138 #define scsi_bufflen(cmd) ((cmd)->request_bufflen)
 139
 140 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 141 {
 142         cmd->resid = resid;
 143 }
 144
 145 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 146 {
 147         return cmd->resid;
 148 }
 149
 150 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 151         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 152
 153 #endif /* _SCSI_SCSI_CMND_H */