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
   9 struct request;
  10 struct scatterlist;
  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         void (*done) (struct scsi_cmnd *);      /* Mid-level done function */
  37
  38         /*
  39          * A SCSI Command is assigned a nonzero serial_number before passed
  40          * to the driver's queue command function.  The serial_number is
  41          * cleared when scsi_done is entered indicating that the command
  42          * has been completed.  It currently doesn't have much use other
  43          * than printk's.  Some lldd's use this number for other purposes.
  44          * It's almost certain that such usages are either incorrect or
  45          * meaningless.  Please kill all usages other than printk's.  Also,
  46          * as this number is always identical to ->pid, please convert
  47          * printk's to use ->pid, so that we can kill this field.
  48          */
  49         unsigned long serial_number;
  50         /*
  51          * This is set to jiffies as it was when the command was first
  52          * allocated.  It is used to time how long the command has
  53          * been outstanding
  54          */
  55         unsigned long jiffies_at_alloc;
  56
  57         int retries;
  58         int allowed;
  59         int timeout_per_command;
  60
  61         unsigned char cmd_len;
  62         enum dma_data_direction sc_data_direction;
  63
  64         /* These elements define the operation we are about to perform */
  65 #define MAX_COMMAND_SIZE        16
  66         unsigned char cmnd[MAX_COMMAND_SIZE];
  67         unsigned request_bufflen;       /* Actual request size */
  68
  69         struct timer_list eh_timeout;   /* Used to time out the command. */
  70         void *request_buffer;           /* Actual requested buffer */
  71
  72         /* These elements define the operation we ultimately want to perform */
  73         unsigned short use_sg;  /* Number of pieces of scatter-gather */
  74         unsigned short sglist_len;      /* size of malloc'd scatter-gather list */
  75
  76         /* offset in cmd we are at (for multi-transfer tgt cmds) */
  77         unsigned offset;
  78
  79         unsigned underflow;     /* Return error if less than
  80                                    this amount is transferred */
  81
  82         unsigned transfersize;  /* How much we are guaranteed to
  83                                    transfer with each SCSI transfer
  84                                    (ie, between disconnect /
  85                                    reconnects.   Probably == sector
  86                                    size */
  87
  88         int resid;              /* Number of bytes requested to be
  89                                    transferred less actual number
  90                                    transferred (0 if not supported) */
  91
  92         struct request *request;        /* The command we are
  93                                            working on */
  94
  95 #define SCSI_SENSE_BUFFERSIZE   96
  96         unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];
  97                                 /* obtained by REQUEST SENSE when
  98                                  * CHECK CONDITION is received on original
  99                                  * command (auto-sense) */
 100
 101         /* Low-level done function - can be used by low-level driver to point
 102          *        to completion function.  Not used by mid/upper level code. */
 103         void (*scsi_done) (struct scsi_cmnd *);
 104
 105         /*
 106          * The following fields can be written to by the host specific code.
 107          * Everything else should be left alone.
 108          */
 109         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 110
 111         unsigned char *host_scribble;   /* The host adapter is allowed to
 112                                          * call scsi_malloc and get some memory
 113                                          * and hang it here.  The host adapter
 114                                          * is also expected to call scsi_free
 115                                          * to release this memory.  (The memory
 116                                          * obtained by scsi_malloc is guaranteed
 117                                          * to be at an address < 16Mb). */
 118
 119         int result;             /* Status code from lower level driver */
 120
 121         unsigned char tag;      /* SCSI-II queued command tag */
 122         unsigned long pid;      /* Process ID, starts at 0. Unique per host. */
 123 };
 124
 125 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 126 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
 127 extern void scsi_put_command(struct scsi_cmnd *);
 128 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
 129                                struct device *);
 130 extern void scsi_io_completion(struct scsi_cmnd *, unsigned int);
 131 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 132 extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
 133
 134 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 135                                  size_t *offset, size_t *len);
 136 extern void scsi_kunmap_atomic_sg(void *virt);
 137
 138 extern struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t);
 139 extern void scsi_free_sgtable(struct scatterlist *, int);
 140
 141 #endif /* _SCSI_SCSI_CMND_H */