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