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_device;
  12
  13
  14 /* embedded in scsi_cmnd */
  15 struct scsi_pointer {
  16         char *ptr;              /* data pointer */
  17         int this_residual;      /* left in this buffer */
  18         struct scatterlist *buffer;     /* which buffer */
  19         int buffers_residual;   /* how many buffers left */
  20
  21         dma_addr_t dma_handle;
  22
  23         volatile int Status;
  24         volatile int Message;
  25         volatile int have_data_in;
  26         volatile int sent_command;
  27         volatile int phase;
  28 };
  29
  30 struct scsi_cmnd {
  31         struct scsi_device *device;
  32         struct list_head list;  /* scsi_cmnd participates in queue lists */
  33         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  34         int eh_eflags;          /* Used by error handlr */
  35         void (*done) (struct scsi_cmnd *);      /* Mid-level done function */
  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 currently doesn't have much use other
  42          * than printk's.  Some lldd's use this number for other purposes.
  43          * It's almost certain that such usages are either incorrect or
  44          * meaningless.  Please kill all usages other than printk's.  Also,
  45          * as this number is always identical to ->pid, please convert
  46          * printk's to use ->pid, so that we can kill this field.
  47          */
  48         unsigned long serial_number;
  49         /*
  50          * This is set to jiffies as it was when the command was first
  51          * allocated.  It is used to time how long the command has
  52          * been outstanding
  53          */
  54         unsigned long jiffies_at_alloc;
  55
  56         int retries;
  57         int allowed;
  58         int timeout_per_command;
  59
  60         unsigned char cmd_len;
  61         enum dma_data_direction sc_data_direction;
  62
  63         /* These elements define the operation we are about to perform */
  64 #define MAX_COMMAND_SIZE        16
  65         unsigned char cmnd[MAX_COMMAND_SIZE];
  66         unsigned request_bufflen;       /* Actual request size */
  67
  68         struct timer_list eh_timeout;   /* Used to time out the command. */
  69         void *request_buffer;           /* Actual requested buffer */
  70
  71         /* These elements define the operation we ultimately want to perform */
  72         unsigned short use_sg;  /* Number of pieces of scatter-gather */
  73         unsigned short sglist_len;      /* size of malloc'd scatter-gather list */
  74
  75         unsigned underflow;     /* Return error if less than
  76                                    this amount is transferred */
  77
  78         unsigned transfersize;  /* How much we are guaranteed to
  79                                    transfer with each SCSI transfer
  80                                    (ie, between disconnect /
  81                                    reconnects.   Probably == sector
  82                                    size */
  83
  84         int resid;              /* Number of bytes requested to be
  85                                    transferred less actual number
  86                                    transferred (0 if not supported) */
  87
  88         struct request *request;        /* The command we are
  89                                            working on */
  90
  91 #define SCSI_SENSE_BUFFERSIZE   96
  92         unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];
  93                                 /* obtained by REQUEST SENSE when
  94                                  * CHECK CONDITION is received on original
  95                                  * command (auto-sense) */
  96
  97         /* Low-level done function - can be used by low-level driver to point
  98          *        to completion function.  Not used by mid/upper level code. */
  99         void (*scsi_done) (struct scsi_cmnd *);
 100
 101         /*
 102          * The following fields can be written to by the host specific code.
 103          * Everything else should be left alone.
 104          */
 105         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 106
 107         unsigned char *host_scribble;   /* The host adapter is allowed to
 108                                          * call scsi_malloc and get some memory
 109                                          * and hang it here.  The host adapter
 110                                          * is also expected to call scsi_free
 111                                          * to release this memory.  (The memory
 112                                          * obtained by scsi_malloc is guaranteed
 113                                          * to be at an address < 16Mb). */
 114
 115         int result;             /* Status code from lower level driver */
 116
 117         unsigned char tag;      /* SCSI-II queued command tag */
 118         unsigned long pid;      /* Process ID, starts at 0. Unique per host. */
 119 };
 120
 121 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 122 extern void scsi_put_command(struct scsi_cmnd *);
 123 extern void scsi_io_completion(struct scsi_cmnd *, unsigned int);
 124 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 125 extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
 126
 127 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 128                                  size_t *offset, size_t *len);
 129 extern void scsi_kunmap_atomic_sg(void *virt);
 130
 131 #endif /* _SCSI_SCSI_CMND_H */