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 #include <scsi/scsi_device.h>
  11 #include <scsi/scsi_request.h>
  12
  13 struct Scsi_Host;
  14 struct scsi_driver;
  15
  16 #include <scsi/scsi_device.h>
  17
  18 /*
  19  * MAX_COMMAND_SIZE is:
  20  * The longest fixed-length SCSI CDB as per the SCSI standard.
  21  * fixed-length means: commands that their size can be determined
  22  * by their opcode and the CDB does not carry a length specifier, (unlike
  23  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
  24  * true and the SCSI standard also defines extended commands and
  25  * vendor specific commands that can be bigger than 16 bytes. The kernel
  26  * will support these using the same infrastructure used for VARLEN CDB's.
  27  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
  28  * supports without specifying a cmd_len by ULD's
  29  */
  30 #define MAX_COMMAND_SIZE 16
  31 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
  32 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
  33 #endif
  34
  35 struct scsi_data_buffer {
  36         struct sg_table table;
  37         unsigned length;
  38         int resid;
  39 };
  40
  41 /* embedded in scsi_cmnd */
  42 struct scsi_pointer {
  43         char *ptr;              /* data pointer */
  44         int this_residual;      /* left in this buffer */
  45         struct scatterlist *buffer;     /* which buffer */
  46         int buffers_residual;   /* how many buffers left */
  47
  48         dma_addr_t dma_handle;
  49
  50         volatile int Status;
  51         volatile int Message;
  52         volatile int have_data_in;
  53         volatile int sent_command;
  54         volatile int phase;
  55 };
  56
  57 /* for scmd->flags */
  58 #define SCMD_TAGGED             (1 << 0)
  59 #define SCMD_UNCHECKED_ISA_DMA  (1 << 1)
  60 #define SCMD_ZONE_WRITE_LOCK    (1 << 2)
  61 #define SCMD_INITIALIZED        (1 << 3)
  62 /* flags preserved across unprep / reprep */
  63 #define SCMD_PRESERVED_FLAGS    (SCMD_UNCHECKED_ISA_DMA | SCMD_INITIALIZED)
  64
  65 struct scsi_cmnd {
  66         struct scsi_request req;
  67         struct scsi_device *device;
  68         struct list_head list;  /* scsi_cmnd participates in queue lists */
  69         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  70         struct delayed_work abort_work;
  71         int eh_eflags;          /* Used by error handlr */
  72
  73         /*
  74          * A SCSI Command is assigned a nonzero serial_number before passed
  75          * to the driver's queue command function.  The serial_number is
  76          * cleared when scsi_done is entered indicating that the command
  77          * has been completed.  It is a bug for LLDDs to use this number
  78          * for purposes other than printk (and even that is only useful
  79          * for debugging).
  80          */
  81         unsigned long serial_number;
  82
  83         /*
  84          * This is set to jiffies as it was when the command was first
  85          * allocated.  It is used to time how long the command has
  86          * been outstanding
  87          */
  88         unsigned long jiffies_at_alloc;
  89
  90         int retries;
  91         int allowed;
  92
  93         unsigned char prot_op;
  94         unsigned char prot_type;
  95         unsigned char prot_flags;
  96
  97         unsigned short cmd_len;
  98         enum dma_data_direction sc_data_direction;
  99
 100         /* These elements define the operation we are about to perform */
 101         unsigned char *cmnd;
 102
 103
 104         /* These elements define the operation we ultimately want to perform */
 105         struct scsi_data_buffer sdb;
 106         struct scsi_data_buffer *prot_sdb;
 107
 108         unsigned underflow;     /* Return error if less than
 109                                    this amount is transferred */
 110
 111         unsigned transfersize;  /* How much we are guaranteed to
 112                                    transfer with each SCSI transfer
 113                                    (ie, between disconnect /
 114                                    reconnects.   Probably == sector
 115                                    size */
 116
 117         struct request *request;        /* The command we are
 118                                            working on */
 119
 120 #define SCSI_SENSE_BUFFERSIZE   96
 121         unsigned char *sense_buffer;
 122                                 /* obtained by REQUEST SENSE when
 123                                  * CHECK CONDITION is received on original
 124                                  * command (auto-sense) */
 125
 126         /* Low-level done function - can be used by low-level driver to point
 127          *        to completion function.  Not used by mid/upper level code. */
 128         void (*scsi_done) (struct scsi_cmnd *);
 129
 130         /*
 131          * The following fields can be written to by the host specific code.
 132          * Everything else should be left alone.
 133          */
 134         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 135
 136         unsigned char *host_scribble;   /* The host adapter is allowed to
 137                                          * call scsi_malloc and get some memory
 138                                          * and hang it here.  The host adapter
 139                                          * is also expected to call scsi_free
 140                                          * to release this memory.  (The memory
 141                                          * obtained by scsi_malloc is guaranteed
 142                                          * to be at an address < 16Mb). */
 143
 144         int result;             /* Status code from lower level driver */
 145         int flags;              /* Command flags */
 146
 147         unsigned char tag;      /* SCSI-II queued command tag */
 148 };
 149
 150 /*
 151  * Return the driver private allocation behind the command.
 152  * Only works if cmd_size is set in the host template.
 153  */
 154 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
 155 {
 156         return cmd + 1;
 157 }
 158
 159 /* make sure not to use it with passthrough commands */
 160 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
 161 {
 162         return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
 163 }
 164
 165 extern void scsi_put_command(struct scsi_cmnd *);
 166 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 167
 168 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 169                                  size_t *offset, size_t *len);
 170 extern void scsi_kunmap_atomic_sg(void *virt);
 171
 172 extern int scsi_init_io(struct scsi_cmnd *cmd);
 173 extern void scsi_initialize_rq(struct request *rq);
 174
 175 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 176 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 177
 178 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 179 {
 180         return cmd->sdb.table.nents;
 181 }
 182
 183 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 184 {
 185         return cmd->sdb.table.sgl;
 186 }
 187
 188 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 189 {
 190         return cmd->sdb.length;
 191 }
 192
 193 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 194 {
 195         cmd->sdb.resid = resid;
 196 }
 197
 198 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 199 {
 200         return cmd->sdb.resid;
 201 }
 202
 203 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 204         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 205
 206 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
 207 {
 208         return blk_bidi_rq(cmd->request) &&
 209                 (cmd->request->next_rq->special != NULL);
 210 }
 211
 212 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
 213 {
 214         return scsi_bidi_cmnd(cmd) ?
 215                 cmd->request->next_rq->special : &cmd->sdb;
 216 }
 217
 218 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
 219 {
 220         return &cmd->sdb;
 221 }
 222
 223 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 224                                            void *buf, int buflen)
 225 {
 226         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 227                                    buf, buflen);
 228 }
 229
 230 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 231                                          void *buf, int buflen)
 232 {
 233         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 234                                  buf, buflen);
 235 }
 236
 237 /*
 238  * The operations below are hints that tell the controller driver how
 239  * to handle I/Os with DIF or similar types of protection information.
 240  */
 241 enum scsi_prot_operations {
 242         /* Normal I/O */
 243         SCSI_PROT_NORMAL = 0,
 244
 245         /* OS-HBA: Protected, HBA-Target: Unprotected */
 246         SCSI_PROT_READ_INSERT,
 247         SCSI_PROT_WRITE_STRIP,
 248
 249         /* OS-HBA: Unprotected, HBA-Target: Protected */
 250         SCSI_PROT_READ_STRIP,
 251         SCSI_PROT_WRITE_INSERT,
 252
 253         /* OS-HBA: Protected, HBA-Target: Protected */
 254         SCSI_PROT_READ_PASS,
 255         SCSI_PROT_WRITE_PASS,
 256 };
 257
 258 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 259 {
 260         scmd->prot_op = op;
 261 }
 262
 263 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 264 {
 265         return scmd->prot_op;
 266 }
 267
 268 enum scsi_prot_flags {
 269         SCSI_PROT_TRANSFER_PI           = 1 << 0,
 270         SCSI_PROT_GUARD_CHECK           = 1 << 1,
 271         SCSI_PROT_REF_CHECK             = 1 << 2,
 272         SCSI_PROT_REF_INCREMENT         = 1 << 3,
 273         SCSI_PROT_IP_CHECKSUM           = 1 << 4,
 274 };
 275
 276 /*
 277  * The controller usually does not know anything about the target it
 278  * is communicating with.  However, when DIX is enabled the controller
 279  * must be know target type so it can verify the protection
 280  * information passed along with the I/O.
 281  */
 282 enum scsi_prot_target_type {
 283         SCSI_PROT_DIF_TYPE0 = 0,
 284         SCSI_PROT_DIF_TYPE1,
 285         SCSI_PROT_DIF_TYPE2,
 286         SCSI_PROT_DIF_TYPE3,
 287 };
 288
 289 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 290 {
 291         scmd->prot_type = type;
 292 }
 293
 294 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 295 {
 296         return scmd->prot_type;
 297 }
 298
 299 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 300 {
 301         return blk_rq_pos(scmd->request);
 302 }
 303
 304 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
 305 {
 306         return scmd->device->sector_size;
 307 }
 308
 309 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
 310 {
 311         return blk_rq_pos(scmd->request) >>
 312                 (ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
 313 }
 314
 315 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 316 {
 317         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 318 }
 319
 320 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 321 {
 322         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 323 }
 324
 325 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 326 {
 327         return cmd->prot_sdb;
 328 }
 329
 330 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 331         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 332
 333 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
 334 {
 335         cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
 336 }
 337
 338 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 339 {
 340         cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 341 }
 342
 343 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 344 {
 345         cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
 346 }
 347
 348 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 349 {
 350         unsigned int xfer_len = scsi_out(scmd)->length;
 351         unsigned int prot_interval = scsi_prot_interval(scmd);
 352
 353         if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
 354                 xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
 355
 356         return xfer_len;
 357 }
 358
 359 #endif /* _SCSI_SCSI_CMND_H */