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 struct scsi_request;
  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         int     sc_magic;
  33
  34         struct scsi_device *device;
  35         struct scsi_request *sc_request;
  36
  37         struct list_head list;  /* scsi_cmnd participates in queue lists */
  38
  39         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  40         int eh_eflags;          /* Used by error handlr */
  41         void (*done) (struct scsi_cmnd *);      /* Mid-level done function */
  42
  43         /*
  44          * A SCSI Command is assigned a nonzero serial_number before passed
  45          * to the driver's queue command function.  The serial_number is
  46          * cleared when scsi_done is entered indicating that the command
  47          * has been completed.  It currently doesn't have much use other
  48          * than printk's.  Some lldd's use this number for other purposes.
  49          * It's almost certain that such usages are either incorrect or
  50          * meaningless.  Please kill all usages other than printk's.  Also,
  51          * as this number is always identical to ->pid, please convert
  52          * printk's to use ->pid, so that we can kill this field.
  53          */
  54         unsigned long serial_number;
  55         /*
  56          * This is set to jiffies as it was when the command was first
  57          * allocated.  It is used to time how long the command has
  58          * been outstanding
  59          */
  60         unsigned long jiffies_at_alloc;
  61
  62         int retries;
  63         int allowed;
  64         int timeout_per_command;
  65
  66         unsigned char cmd_len;
  67         unsigned char old_cmd_len;
  68         enum dma_data_direction sc_data_direction;
  69         enum dma_data_direction sc_old_data_direction;
  70
  71         /* These elements define the operation we are about to perform */
  72 #define MAX_COMMAND_SIZE        16
  73         unsigned char cmnd[MAX_COMMAND_SIZE];
  74         unsigned request_bufflen;       /* Actual request size */
  75
  76         struct timer_list eh_timeout;   /* Used to time out the command. */
  77         void *request_buffer;           /* Actual requested buffer */
  78
  79         /* These elements define the operation we ultimately want to perform */
  80         unsigned char data_cmnd[MAX_COMMAND_SIZE];
  81         unsigned short old_use_sg;      /* We save  use_sg here when requesting
  82                                          * sense info */
  83         unsigned short use_sg;  /* Number of pieces of scatter-gather */
  84         unsigned short sglist_len;      /* size of malloc'd scatter-gather list */
  85         unsigned bufflen;       /* Size of data buffer */
  86         void *buffer;           /* Data buffer */
  87
  88         unsigned underflow;     /* Return error if less than
  89                                    this amount is transferred */
  90         unsigned old_underflow; /* save underflow here when reusing the
  91                                  * command for error handling */
  92
  93         unsigned transfersize;  /* How much we are guaranteed to
  94                                    transfer with each SCSI transfer
  95                                    (ie, between disconnect /
  96                                    reconnects.   Probably == sector
  97                                    size */
  98
  99         int resid;              /* Number of bytes requested to be
 100                                    transferred less actual number
 101                                    transferred (0 if not supported) */
 102
 103         struct request *request;        /* The command we are
 104                                            working on */
 105
 106 #define SCSI_SENSE_BUFFERSIZE   96
 107         unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];              /* obtained by REQUEST SENSE
 108                                                  * when CHECK CONDITION is
 109                                                  * received on original command
 110                                                  * (auto-sense) */
 111
 112         /* Low-level done function - can be used by low-level driver to point
 113          *        to completion function.  Not used by mid/upper level code. */
 114         void (*scsi_done) (struct scsi_cmnd *);
 115
 116         /*
 117          * The following fields can be written to by the host specific code.
 118          * Everything else should be left alone.
 119          */
 120         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 121
 122         unsigned char *host_scribble;   /* The host adapter is allowed to
 123                                            * call scsi_malloc and get some memory
 124                                            * and hang it here.     The host adapter
 125                                            * is also expected to call scsi_free
 126                                            * to release this memory.  (The memory
 127                                            * obtained by scsi_malloc is guaranteed
 128                                            * to be at an address < 16Mb). */
 129
 130         int result;             /* Status code from lower level driver */
 131
 132         unsigned char tag;      /* SCSI-II queued command tag */
 133         unsigned long pid;      /* Process ID, starts at 0. Unique per host. */
 134 };
 135
 136 /*
 137  * These are the values that scsi_cmd->state can take.
 138  */
 139 #define SCSI_STATE_TIMEOUT         0x1000
 140 #define SCSI_STATE_FINISHED        0x1001
 141 #define SCSI_STATE_FAILED          0x1002
 142 #define SCSI_STATE_QUEUED          0x1003
 143 #define SCSI_STATE_UNUSED          0x1006
 144 #define SCSI_STATE_DISCONNECTING   0x1008
 145 #define SCSI_STATE_INITIALIZING    0x1009
 146 #define SCSI_STATE_BHQUEUE         0x100a
 147 #define SCSI_STATE_MLQUEUE         0x100b
 148
 149
 150 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 151 extern void scsi_put_command(struct scsi_cmnd *);
 152 extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
 153 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 154
 155 #endif /* _SCSI_SCSI_CMND_H */