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/blkdev.h>
   6 #include <linux/list.h>
   7 #include <linux/types.h>
   8 #include <linux/timer.h>
   9 #include <linux/scatterlist.h>
  10
  11 struct Scsi_Host;
  12 struct scsi_device;
  13
  14 /*
  15  * MAX_COMMAND_SIZE is:
  16  * The longest fixed-length SCSI CDB as per the SCSI standard.
  17  * fixed-length means: commands that their size can be determined
  18  * by their opcode and the CDB does not carry a length specifier, (unlike
  19  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
  20  * true and the SCSI standard also defines extended commands and
  21  * vendor specific commands that can be bigger than 16 bytes. The kernel
  22  * will support these using the same infrastructure used for VARLEN CDB's.
  23  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
  24  * supports without specifying a cmd_len by ULD's
  25  */
  26 #define MAX_COMMAND_SIZE 16
  27 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
  28 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
  29 #endif
  30
  31 struct scsi_data_buffer {
  32         struct sg_table table;
  33         unsigned length;
  34         int resid;
  35 };
  36
  37 /* embedded in scsi_cmnd */
  38 struct scsi_pointer {
  39         char *ptr;              /* data pointer */
  40         int this_residual;      /* left in this buffer */
  41         struct scatterlist *buffer;     /* which buffer */
  42         int buffers_residual;   /* how many buffers left */
  43
  44         dma_addr_t dma_handle;
  45
  46         volatile int Status;
  47         volatile int Message;
  48         volatile int have_data_in;
  49         volatile int sent_command;
  50         volatile int phase;
  51 };
  52
  53 struct scsi_cmnd {
  54         struct scsi_device *device;
  55         struct list_head list;  /* scsi_cmnd participates in queue lists */
  56         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  57         int eh_eflags;          /* Used by error handlr */
  58
  59         /*
  60          * A SCSI Command is assigned a nonzero serial_number before passed
  61          * to the driver's queue command function.  The serial_number is
  62          * cleared when scsi_done is entered indicating that the command
  63          * has been completed.  It is a bug for LLDDs to use this number
  64          * for purposes other than printk (and even that is only useful
  65          * for debugging).
  66          */
  67         unsigned long serial_number;
  68
  69         /*
  70          * This is set to jiffies as it was when the command was first
  71          * allocated.  It is used to time how long the command has
  72          * been outstanding
  73          */
  74         unsigned long jiffies_at_alloc;
  75
  76         int retries;
  77         int allowed;
  78         int timeout_per_command;
  79
  80         unsigned char prot_op;
  81         unsigned char prot_type;
  82
  83         unsigned short cmd_len;
  84         enum dma_data_direction sc_data_direction;
  85
  86         /* These elements define the operation we are about to perform */
  87         unsigned char *cmnd;
  88
  89         struct timer_list eh_timeout;   /* Used to time out the command. */
  90
  91         /* These elements define the operation we ultimately want to perform */
  92         struct scsi_data_buffer sdb;
  93         struct scsi_data_buffer *prot_sdb;
  94
  95         unsigned underflow;     /* Return error if less than
  96                                    this amount is transferred */
  97
  98         unsigned transfersize;  /* How much we are guaranteed to
  99                                    transfer with each SCSI transfer
 100                                    (ie, between disconnect /
 101                                    reconnects.   Probably == sector
 102                                    size */
 103
 104         struct request *request;        /* The command we are
 105                                            working on */
 106
 107 #define SCSI_SENSE_BUFFERSIZE   96
 108         unsigned char *sense_buffer;
 109                                 /* obtained by REQUEST SENSE when
 110                                  * CHECK CONDITION is received on original
 111                                  * command (auto-sense) */
 112
 113         /* Low-level done function - can be used by low-level driver to point
 114          *        to completion function.  Not used by mid/upper level code. */
 115         void (*scsi_done) (struct scsi_cmnd *);
 116
 117         /*
 118          * The following fields can be written to by the host specific code.
 119          * Everything else should be left alone.
 120          */
 121         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 122
 123         unsigned char *host_scribble;   /* The host adapter is allowed to
 124                                          * call scsi_malloc and get some memory
 125                                          * and hang it here.  The host adapter
 126                                          * is also expected to call scsi_free
 127                                          * to release this memory.  (The memory
 128                                          * obtained by scsi_malloc is guaranteed
 129                                          * to be at an address < 16Mb). */
 130
 131         int result;             /* Status code from lower level driver */
 132
 133         unsigned char tag;      /* SCSI-II queued command tag */
 134 };
 135
 136 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 137 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
 138 extern void scsi_put_command(struct scsi_cmnd *);
 139 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
 140                                struct device *);
 141 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 142 extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
 143
 144 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 145                                  size_t *offset, size_t *len);
 146 extern void scsi_kunmap_atomic_sg(void *virt);
 147
 148 extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
 149 extern void scsi_release_buffers(struct scsi_cmnd *cmd);
 150
 151 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 152 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 153
 154 struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
 155 void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
 156
 157 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 158 {
 159         return cmd->sdb.table.nents;
 160 }
 161
 162 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 163 {
 164         return cmd->sdb.table.sgl;
 165 }
 166
 167 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 168 {
 169         return cmd->sdb.length;
 170 }
 171
 172 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 173 {
 174         cmd->sdb.resid = resid;
 175 }
 176
 177 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 178 {
 179         return cmd->sdb.resid;
 180 }
 181
 182 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 183         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 184
 185 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
 186 {
 187         return blk_bidi_rq(cmd->request) &&
 188                 (cmd->request->next_rq->special != NULL);
 189 }
 190
 191 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
 192 {
 193         return scsi_bidi_cmnd(cmd) ?
 194                 cmd->request->next_rq->special : &cmd->sdb;
 195 }
 196
 197 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
 198 {
 199         return &cmd->sdb;
 200 }
 201
 202 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 203                                            void *buf, int buflen)
 204 {
 205         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 206                                    buf, buflen);
 207 }
 208
 209 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 210                                          void *buf, int buflen)
 211 {
 212         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 213                                  buf, buflen);
 214 }
 215
 216 /*
 217  * The operations below are hints that tell the controller driver how
 218  * to handle I/Os with DIF or similar types of protection information.
 219  */
 220 enum scsi_prot_operations {
 221         /* Normal I/O */
 222         SCSI_PROT_NORMAL = 0,
 223
 224         /* OS-HBA: Protected, HBA-Target: Unprotected */
 225         SCSI_PROT_READ_INSERT,
 226         SCSI_PROT_WRITE_STRIP,
 227
 228         /* OS-HBA: Unprotected, HBA-Target: Protected */
 229         SCSI_PROT_READ_STRIP,
 230         SCSI_PROT_WRITE_INSERT,
 231
 232         /* OS-HBA: Protected, HBA-Target: Protected */
 233         SCSI_PROT_READ_PASS,
 234         SCSI_PROT_WRITE_PASS,
 235
 236         /* OS-HBA: Protected, HBA-Target: Protected, checksum conversion */
 237         SCSI_PROT_READ_CONVERT,
 238         SCSI_PROT_WRITE_CONVERT,
 239 };
 240
 241 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 242 {
 243         scmd->prot_op = op;
 244 }
 245
 246 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 247 {
 248         return scmd->prot_op;
 249 }
 250
 251 /*
 252  * The controller usually does not know anything about the target it
 253  * is communicating with.  However, when DIX is enabled the controller
 254  * must be know target type so it can verify the protection
 255  * information passed along with the I/O.
 256  */
 257 enum scsi_prot_target_type {
 258         SCSI_PROT_DIF_TYPE0 = 0,
 259         SCSI_PROT_DIF_TYPE1,
 260         SCSI_PROT_DIF_TYPE2,
 261         SCSI_PROT_DIF_TYPE3,
 262 };
 263
 264 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 265 {
 266         scmd->prot_type = type;
 267 }
 268
 269 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 270 {
 271         return scmd->prot_type;
 272 }
 273
 274 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 275 {
 276         return scmd->request->sector;
 277 }
 278
 279 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 280 {
 281         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 282 }
 283
 284 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 285 {
 286         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 287 }
 288
 289 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 290 {
 291         return cmd->prot_sdb;
 292 }
 293
 294 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 295         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 296
 297 #endif /* _SCSI_SCSI_CMND_H */