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
   8 struct request;
   9 struct scatterlist;
  10 struct scsi_device;
  11 struct scsi_request;
  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         int     sc_magic;
  32
  33         struct scsi_device *device;
  34         struct scsi_request *sc_request;
  35
  36         struct list_head list;  /* scsi_cmnd participates in queue lists */
  37
  38         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  39         int eh_eflags;          /* Used by error handlr */
  40         void (*done) (struct scsi_cmnd *);      /* Mid-level done function */
  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 currently doesn't have much use other
  47          * than printk's.  Some lldd's use this number for other purposes.
  48          * It's almost certain that such usages are either incorrect or
  49          * meaningless.  Please kill all usages other than printk's.  Also,
  50          * as this number is always identical to ->pid, please convert
  51          * printk's to use ->pid, so that we can kill this field.
  52          */
  53         unsigned long serial_number;
  54         /*
  55          * This is set to jiffies as it was when the command was first
  56          * allocated.  It is used to time how long the command has
  57          * been outstanding
  58          */
  59         unsigned long jiffies_at_alloc;
  60
  61         int retries;
  62         int allowed;
  63         int timeout_per_command;
  64
  65         unsigned char cmd_len;
  66         unsigned char old_cmd_len;
  67         enum dma_data_direction sc_data_direction;
  68         enum dma_data_direction sc_old_data_direction;
  69
  70         /* These elements define the operation we are about to perform */
  71 #define MAX_COMMAND_SIZE        16
  72         unsigned char cmnd[MAX_COMMAND_SIZE];
  73         unsigned request_bufflen;       /* Actual request size */
  74
  75         struct timer_list eh_timeout;   /* Used to time out the command. */
  76         void *request_buffer;           /* Actual requested buffer */
  77
  78         /* These elements define the operation we ultimately want to perform */
  79         unsigned char data_cmnd[MAX_COMMAND_SIZE];
  80         unsigned short old_use_sg;      /* We save  use_sg here when requesting
  81                                          * sense info */
  82         unsigned short use_sg;  /* Number of pieces of scatter-gather */
  83         unsigned short sglist_len;      /* size of malloc'd scatter-gather list */
  84         unsigned bufflen;       /* Size of data buffer */
  85         void *buffer;           /* Data buffer */
  86
  87         unsigned underflow;     /* Return error if less than
  88                                    this amount is transferred */
  89         unsigned old_underflow; /* save underflow here when reusing the
  90                                  * command for error handling */
  91
  92         unsigned transfersize;  /* How much we are guaranteed to
  93                                    transfer with each SCSI transfer
  94                                    (ie, between disconnect /
  95                                    reconnects.   Probably == sector
  96                                    size */
  97
  98         int resid;              /* Number of bytes requested to be
  99                                    transferred less actual number
 100                                    transferred (0 if not supported) */
 101
 102         struct request *request;        /* The command we are
 103                                            working on */
 104
 105 #define SCSI_SENSE_BUFFERSIZE   96
 106         unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];              /* obtained by REQUEST SENSE
 107                                                  * when CHECK CONDITION is
 108                                                  * received on original command
 109                                                  * (auto-sense) */
 110
 111         /* Low-level done function - can be used by low-level driver to point
 112          *        to completion function.  Not used by mid/upper level code. */
 113         void (*scsi_done) (struct scsi_cmnd *);
 114
 115         /*
 116          * The following fields can be written to by the host specific code.
 117          * Everything else should be left alone.
 118          */
 119         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 120
 121         unsigned char *host_scribble;   /* The host adapter is allowed to
 122                                            * call scsi_malloc and get some memory
 123                                            * and hang it here.     The host adapter
 124                                            * is also expected to call scsi_free
 125                                            * to release this memory.  (The memory
 126                                            * obtained by scsi_malloc is guaranteed
 127                                            * to be at an address < 16Mb). */
 128
 129         int result;             /* Status code from lower level driver */
 130
 131         unsigned char tag;      /* SCSI-II queued command tag */
 132         unsigned long pid;      /* Process ID, starts at 0. Unique per host. */
 133 };
 134
 135 /*
 136  * These are the values that scsi_cmd->state can take.
 137  */
 138 #define SCSI_STATE_TIMEOUT         0x1000
 139 #define SCSI_STATE_FINISHED        0x1001
 140 #define SCSI_STATE_FAILED          0x1002
 141 #define SCSI_STATE_QUEUED          0x1003
 142 #define SCSI_STATE_UNUSED          0x1006
 143 #define SCSI_STATE_DISCONNECTING   0x1008
 144 #define SCSI_STATE_INITIALIZING    0x1009
 145 #define SCSI_STATE_BHQUEUE         0x100a
 146 #define SCSI_STATE_MLQUEUE         0x100b
 147
 148
 149 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, int);
 150 extern void scsi_put_command(struct scsi_cmnd *);
 151 extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
 152 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 153
 154 #endif /* _SCSI_SCSI_CMND_H */