include/scsi/scsi_cmnd.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _SCSI_SCSI_CMND_H
   3 #define _SCSI_SCSI_CMND_H
   4
   5 #include <linux/dma-mapping.h>
   6 #include <linux/blkdev.h>
   7 #include <linux/t10-pi.h>
   8 #include <linux/list.h>
   9 #include <linux/types.h>
  10 #include <linux/timer.h>
  11 #include <linux/scatterlist.h>
  12 #include <scsi/scsi_device.h>
  13
  14 struct Scsi_Host;
  15
  16 /*
  17  * MAX_COMMAND_SIZE is:
  18  * The longest fixed-length SCSI CDB as per the SCSI standard.
  19  * fixed-length means: commands that their size can be determined
  20  * by their opcode and the CDB does not carry a length specifier, (unlike
  21  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
  22  * true and the SCSI standard also defines extended commands and
  23  * vendor specific commands that can be bigger than 16 bytes. The kernel
  24  * will support these using the same infrastructure used for VARLEN CDB's.
  25  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
  26  * supports without specifying a cmd_len by ULD's
  27  */
  28 #define MAX_COMMAND_SIZE 16
  29
  30 struct scsi_data_buffer {
  31         struct sg_table table;
  32         unsigned length;
  33 };
  34
  35 /* embedded in scsi_cmnd */
  36 struct scsi_pointer {
  37         char *ptr;              /* data pointer */
  38         int this_residual;      /* left in this buffer */
  39         struct scatterlist *buffer;     /* which buffer */
  40         int buffers_residual;   /* how many buffers left */
  41
  42         dma_addr_t dma_handle;
  43
  44         volatile int Status;
  45         volatile int Message;
  46         volatile int have_data_in;
  47         volatile int sent_command;
  48         volatile int phase;
  49 };
  50
  51 /* for scmd->flags */
  52 #define SCMD_TAGGED             (1 << 0)
  53 #define SCMD_INITIALIZED        (1 << 1)
  54 #define SCMD_LAST               (1 << 2)
  55 #define SCMD_FAIL_IF_RECOVERING (1 << 4)
  56 /* flags preserved across unprep / reprep */
  57 #define SCMD_PRESERVED_FLAGS    (SCMD_INITIALIZED | SCMD_FAIL_IF_RECOVERING)
  58
  59 /* for scmd->state */
  60 #define SCMD_STATE_COMPLETE     0
  61 #define SCMD_STATE_INFLIGHT     1
  62
  63 enum scsi_cmnd_submitter {
  64         SUBMITTED_BY_BLOCK_LAYER = 0,
  65         SUBMITTED_BY_SCSI_ERROR_HANDLER = 1,
  66         SUBMITTED_BY_SCSI_RESET_IOCTL = 2,
  67 } __packed;
  68
  69 struct scsi_cmnd {
  70         struct scsi_device *device;
  71         struct list_head eh_entry; /* entry for the host eh_abort_list/eh_cmd_q */
  72         struct delayed_work abort_work;
  73
  74         struct rcu_head rcu;
  75
  76         int eh_eflags;          /* Used by error handlr */
  77
  78         int budget_token;
  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         enum scsi_cmnd_submitter submitter;
  94
  95         unsigned short cmd_len;
  96         enum dma_data_direction sc_data_direction;
  97
  98         unsigned char cmnd[32]; /* SCSI CDB */
  99
 100         /* These elements define the operation we ultimately want to perform */
 101         struct scsi_data_buffer sdb;
 102         struct scsi_data_buffer *prot_sdb;
 103
 104         unsigned underflow;     /* Return error if less than
 105                                    this amount is transferred */
 106
 107         unsigned transfersize;  /* How much we are guaranteed to
 108                                    transfer with each SCSI transfer
 109                                    (ie, between disconnect /
 110                                    reconnects.   Probably == sector
 111                                    size */
 112         unsigned resid_len;     /* residual count */
 113         unsigned sense_len;
 114         unsigned char *sense_buffer;
 115                                 /* obtained by REQUEST SENSE when
 116                                  * CHECK CONDITION is received on original
 117                                  * command (auto-sense). Length must be
 118                                  * SCSI_SENSE_BUFFERSIZE bytes. */
 119
 120         int flags;              /* Command flags */
 121         unsigned long state;    /* Command completion state */
 122
 123         unsigned int extra_len; /* length of alignment and padding */
 124
 125         /*
 126          * The fields below can be modified by the LLD but the fields above
 127          * must not be modified.
 128          */
 129
 130         unsigned char *host_scribble;   /* The host adapter is allowed to
 131                                          * call scsi_malloc and get some memory
 132                                          * and hang it here.  The host adapter
 133                                          * is also expected to call scsi_free
 134                                          * to release this memory.  (The memory
 135                                          * obtained by scsi_malloc is guaranteed
 136                                          * to be at an address < 16Mb). */
 137
 138         int result;             /* Status code from lower level driver */
 139 };
 140
 141 /* Variant of blk_mq_rq_from_pdu() that verifies the type of its argument. */
 142 static inline struct request *scsi_cmd_to_rq(struct scsi_cmnd *scmd)
 143 {
 144         return blk_mq_rq_from_pdu(scmd);
 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 void scsi_done(struct scsi_cmnd *cmd);
 157 void scsi_done_direct(struct scsi_cmnd *cmd);
 158
 159 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 160
 161 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 162                                  size_t *offset, size_t *len);
 163 extern void scsi_kunmap_atomic_sg(void *virt);
 164
 165 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
 166 void scsi_free_sgtables(struct scsi_cmnd *cmd);
 167
 168 #ifdef CONFIG_SCSI_DMA
 169 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 170 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 171 #else /* !CONFIG_SCSI_DMA */
 172 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
 173 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
 174 #endif /* !CONFIG_SCSI_DMA */
 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, unsigned int resid)
 192 {
 193         cmd->resid_len = resid;
 194 }
 195
 196 static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
 197 {
 198         return cmd->resid_len;
 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_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 205                                            const void *buf, int buflen)
 206 {
 207         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 208                                    buf, buflen);
 209 }
 210
 211 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 212                                          void *buf, int buflen)
 213 {
 214         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 215                                  buf, buflen);
 216 }
 217
 218 static inline sector_t scsi_get_sector(struct scsi_cmnd *scmd)
 219 {
 220         return blk_rq_pos(scsi_cmd_to_rq(scmd));
 221 }
 222
 223 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 224 {
 225         unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
 226
 227         return blk_rq_pos(scsi_cmd_to_rq(scmd)) >> shift;
 228 }
 229
 230 static inline unsigned int scsi_logical_block_count(struct scsi_cmnd *scmd)
 231 {
 232         unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
 233
 234         return blk_rq_bytes(scsi_cmd_to_rq(scmd)) >> shift;
 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 u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
 300 {
 301         struct request *rq = blk_mq_rq_from_pdu(scmd);
 302
 303         return t10_pi_ref_tag(rq);
 304 }
 305
 306 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
 307 {
 308         return scmd->device->sector_size;
 309 }
 310
 311 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 312 {
 313         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 314 }
 315
 316 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 317 {
 318         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 319 }
 320
 321 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 322 {
 323         return cmd->prot_sdb;
 324 }
 325
 326 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 327         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 328
 329 static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
 330 {
 331         cmd->result = (cmd->result & 0xffffff00) | status;
 332 }
 333
 334 static inline u8 get_status_byte(struct scsi_cmnd *cmd)
 335 {
 336         return cmd->result & 0xff;
 337 }
 338
 339 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 340 {
 341         cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 342 }
 343
 344 static inline u8 get_host_byte(struct scsi_cmnd *cmd)
 345 {
 346         return (cmd->result >> 16) & 0xff;
 347 }
 348
 349 /**
 350  * scsi_msg_to_host_byte() - translate message byte
 351  *
 352  * Translate the SCSI parallel message byte to a matching
 353  * host byte setting. A message of COMMAND_COMPLETE indicates
 354  * a successful command execution, any other message indicate
 355  * an error. As the messages themselves only have a meaning
 356  * for the SCSI parallel protocol this function translates
 357  * them into a matching host byte value for SCSI EH.
 358  */
 359 static inline void scsi_msg_to_host_byte(struct scsi_cmnd *cmd, u8 msg)
 360 {
 361         switch (msg) {
 362         case COMMAND_COMPLETE:
 363                 break;
 364         case ABORT_TASK_SET:
 365                 set_host_byte(cmd, DID_ABORT);
 366                 break;
 367         case TARGET_RESET:
 368                 set_host_byte(cmd, DID_RESET);
 369                 break;
 370         default:
 371                 set_host_byte(cmd, DID_ERROR);
 372                 break;
 373         }
 374 }
 375
 376 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 377 {
 378         unsigned int xfer_len = scmd->sdb.length;
 379         unsigned int prot_interval = scsi_prot_interval(scmd);
 380
 381         if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
 382                 xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
 383
 384         return xfer_len;
 385 }
 386
 387 extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
 388                              u8 key, u8 asc, u8 ascq);
 389
 390 struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf,
 391                                    blk_mq_req_flags_t flags);
 392
 393 #endif /* _SCSI_SCSI_CMND_H */