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         unsigned short state;
  35         unsigned short owner;
  36         struct scsi_request *sc_request;
  37
  38         struct list_head list;  /* scsi_cmnd participates in queue lists */
  39
  40         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  41         int eh_state;           /* Used for state tracking in error handlr */
  42         int eh_eflags;          /* Used by error handlr */
  43         void (*done) (struct scsi_cmnd *);      /* Mid-level done function */
  44
  45         /*
  46          * A SCSI Command is assigned a nonzero serial_number when internal_cmnd
  47          * passes it to the driver's queue command function.  The serial_number
  48          * is cleared when scsi_done is entered indicating that the command has
  49          * been completed.  If a timeout occurs, the serial number at the moment
  50          * of timeout is copied into serial_number_at_timeout.  By subsequently
  51          * comparing the serial_number and serial_number_at_timeout fields
  52          * during abort or reset processing, we can detect whether the command
  53          * has already completed.  This also detects cases where the command has
  54          * completed and the SCSI Command structure has already being reused
  55          * for another command, so that we can avoid incorrectly aborting or
  56          * resetting the new command.
  57          */
  58         unsigned long serial_number;
  59         unsigned long serial_number_at_timeout;
  60
  61         int retries;
  62         int allowed;
  63         int timeout_per_command;
  64         int timeout_total;
  65         int timeout;
  66
  67         /*
  68          * We handle the timeout differently if it happens when a reset,
  69          * abort, etc are in process.
  70          */
  71         unsigned volatile char internal_timeout;
  72
  73         unsigned char cmd_len;
  74         unsigned char old_cmd_len;
  75         enum dma_data_direction sc_data_direction;
  76         enum dma_data_direction sc_old_data_direction;
  77
  78         /* These elements define the operation we are about to perform */
  79 #define MAX_COMMAND_SIZE        16
  80         unsigned char cmnd[MAX_COMMAND_SIZE];
  81         unsigned request_bufflen;       /* Actual request size */
  82
  83         struct timer_list eh_timeout;   /* Used to time out the command. */
  84         void *request_buffer;           /* Actual requested buffer */
  85
  86         /* These elements define the operation we ultimately want to perform */
  87         unsigned char data_cmnd[MAX_COMMAND_SIZE];
  88         unsigned short old_use_sg;      /* We save  use_sg here when requesting
  89                                          * sense info */
  90         unsigned short use_sg;  /* Number of pieces of scatter-gather */
  91         unsigned short sglist_len;      /* size of malloc'd scatter-gather list */
  92         unsigned short abort_reason;    /* If the mid-level code requests an
  93                                          * abort, this is the reason. */
  94         unsigned bufflen;       /* Size of data buffer */
  95         void *buffer;           /* Data buffer */
  96
  97         unsigned underflow;     /* Return error if less than
  98                                    this amount is transferred */
  99         unsigned old_underflow; /* save underflow here when reusing the
 100                                  * command for error handling */
 101
 102         unsigned transfersize;  /* How much we are guaranteed to
 103                                    transfer with each SCSI transfer
 104                                    (ie, between disconnect /
 105                                    reconnects.   Probably == sector
 106                                    size */
 107
 108         int resid;              /* Number of bytes requested to be
 109                                    transferred less actual number
 110                                    transferred (0 if not supported) */
 111
 112         struct request *request;        /* The command we are
 113                                            working on */
 114
 115 #define SCSI_SENSE_BUFFERSIZE   96
 116         unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];              /* obtained by REQUEST SENSE
 117                                                  * when CHECK CONDITION is
 118                                                  * received on original command
 119                                                  * (auto-sense) */
 120
 121         /* Low-level done function - can be used by low-level driver to point
 122          *        to completion function.  Not used by mid/upper level code. */
 123         void (*scsi_done) (struct scsi_cmnd *);
 124
 125         /*
 126          * The following fields can be written to by the host specific code.
 127          * Everything else should be left alone.
 128          */
 129         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 130
 131         unsigned char *host_scribble;   /* The host adapter is allowed to
 132                                            * call scsi_malloc and get some memory
 133                                            * and hang it here.     The host adapter
 134                                            * is also expected to call scsi_free
 135                                            * to release this memory.  (The memory
 136                                            * obtained by scsi_malloc is guaranteed
 137                                            * to be at an address < 16Mb). */
 138
 139         int result;             /* Status code from lower level driver */
 140
 141         unsigned char tag;      /* SCSI-II queued command tag */
 142         unsigned long pid;      /* Process ID, starts at 0 */
 143 };
 144
 145 /*
 146  * These are the values that scsi_cmd->state can take.
 147  */
 148 #define SCSI_STATE_TIMEOUT         0x1000
 149 #define SCSI_STATE_FINISHED        0x1001
 150 #define SCSI_STATE_FAILED          0x1002
 151 #define SCSI_STATE_QUEUED          0x1003
 152 #define SCSI_STATE_UNUSED          0x1006
 153 #define SCSI_STATE_DISCONNECTING   0x1008
 154 #define SCSI_STATE_INITIALIZING    0x1009
 155 #define SCSI_STATE_BHQUEUE         0x100a
 156 #define SCSI_STATE_MLQUEUE         0x100b
 157
 158
 159 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, int);
 160 extern void scsi_put_command(struct scsi_cmnd *);
 161 extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
 162 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 163
 164 #endif /* _SCSI_SCSI_CMND_H */