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 /*
  56  * libata uses SCSI EH to fetch sense data for successful commands.
  57  * SCSI EH should not overwrite scmd->result when SCMD_FORCE_EH_SUCCESS is set.
  58  */
  59 #define SCMD_FORCE_EH_SUCCESS   (1 << 3)
  60 #define SCMD_FAIL_IF_RECOVERING (1 << 4)
  61 /* flags preserved across unprep / reprep */
  62 #define SCMD_PRESERVED_FLAGS    (SCMD_INITIALIZED | SCMD_FAIL_IF_RECOVERING)
  63
  64 /* for scmd->state */
  65 #define SCMD_STATE_COMPLETE     0
  66 #define SCMD_STATE_INFLIGHT     1
  67
  68 enum scsi_cmnd_submitter {
  69         SUBMITTED_BY_BLOCK_LAYER = 0,
  70         SUBMITTED_BY_SCSI_ERROR_HANDLER = 1,
  71         SUBMITTED_BY_SCSI_RESET_IOCTL = 2,
  72 } __packed;
  73
  74 struct scsi_cmnd {
  75         struct scsi_device *device;
  76         struct list_head eh_entry; /* entry for the host eh_abort_list/eh_cmd_q */
  77         struct delayed_work abort_work;
  78
  79         struct rcu_head rcu;
  80
  81         int eh_eflags;          /* Used by error handlr */
  82
  83         int budget_token;
  84
  85         /*
  86          * This is set to jiffies as it was when the command was first
  87          * allocated.  It is used to time how long the command has
  88          * been outstanding
  89          */
  90         unsigned long jiffies_at_alloc;
  91
  92         int retries;
  93         int allowed;
  94
  95         unsigned char prot_op;
  96         unsigned char prot_type;
  97         unsigned char prot_flags;
  98         enum scsi_cmnd_submitter submitter;
  99
 100         unsigned short cmd_len;
 101         enum dma_data_direction sc_data_direction;
 102
 103         unsigned char cmnd[32]; /* SCSI CDB */
 104
 105         /* These elements define the operation we ultimately want to perform */
 106         struct scsi_data_buffer sdb;
 107         struct scsi_data_buffer *prot_sdb;
 108
 109         unsigned underflow;     /* Return error if less than
 110                                    this amount is transferred */
 111
 112         unsigned transfersize;  /* How much we are guaranteed to
 113                                    transfer with each SCSI transfer
 114                                    (ie, between disconnect /
 115                                    reconnects.   Probably == sector
 116                                    size */
 117         unsigned resid_len;     /* residual count */
 118         unsigned sense_len;
 119         unsigned char *sense_buffer;
 120                                 /* obtained by REQUEST SENSE when
 121                                  * CHECK CONDITION is received on original
 122                                  * command (auto-sense). Length must be
 123                                  * SCSI_SENSE_BUFFERSIZE bytes. */
 124
 125         int flags;              /* Command flags */
 126         unsigned long state;    /* Command completion state */
 127
 128         unsigned int extra_len; /* length of alignment and padding */
 129
 130         /*
 131          * The fields below can be modified by the LLD but the fields above
 132          * must not be modified.
 133          */
 134
 135         unsigned char *host_scribble;   /* The host adapter is allowed to
 136                                          * call scsi_malloc and get some memory
 137                                          * and hang it here.  The host adapter
 138                                          * is also expected to call scsi_free
 139                                          * to release this memory.  (The memory
 140                                          * obtained by scsi_malloc is guaranteed
 141                                          * to be at an address < 16Mb). */
 142
 143         int result;             /* Status code from lower level driver */
 144 };
 145
 146 /* Variant of blk_mq_rq_from_pdu() that verifies the type of its argument. */
 147 static inline struct request *scsi_cmd_to_rq(struct scsi_cmnd *scmd)
 148 {
 149         return blk_mq_rq_from_pdu(scmd);
 150 }
 151
 152 /*
 153  * Return the driver private allocation behind the command.
 154  * Only works if cmd_size is set in the host template.
 155  */
 156 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
 157 {
 158         return cmd + 1;
 159 }
 160
 161 void scsi_done(struct scsi_cmnd *cmd);
 162 void scsi_done_direct(struct scsi_cmnd *cmd);
 163
 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 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
 171 void scsi_free_sgtables(struct scsi_cmnd *cmd);
 172
 173 #ifdef CONFIG_SCSI_DMA
 174 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 175 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 176 #else /* !CONFIG_SCSI_DMA */
 177 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
 178 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
 179 #endif /* !CONFIG_SCSI_DMA */
 180
 181 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 182 {
 183         return cmd->sdb.table.nents;
 184 }
 185
 186 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 187 {
 188         return cmd->sdb.table.sgl;
 189 }
 190
 191 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 192 {
 193         return cmd->sdb.length;
 194 }
 195
 196 static inline void scsi_set_resid(struct scsi_cmnd *cmd, unsigned int resid)
 197 {
 198         cmd->resid_len = resid;
 199 }
 200
 201 static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
 202 {
 203         return cmd->resid_len;
 204 }
 205
 206 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 207         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 208
 209 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 210                                            const void *buf, int buflen)
 211 {
 212         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 213                                    buf, buflen);
 214 }
 215
 216 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 217                                          void *buf, int buflen)
 218 {
 219         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 220                                  buf, buflen);
 221 }
 222
 223 static inline sector_t scsi_get_sector(struct scsi_cmnd *scmd)
 224 {
 225         return blk_rq_pos(scsi_cmd_to_rq(scmd));
 226 }
 227
 228 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 229 {
 230         unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
 231
 232         return blk_rq_pos(scsi_cmd_to_rq(scmd)) >> shift;
 233 }
 234
 235 static inline unsigned int scsi_logical_block_count(struct scsi_cmnd *scmd)
 236 {
 237         unsigned int shift = ilog2(scmd->device->sector_size);
 238
 239         return blk_rq_bytes(scsi_cmd_to_rq(scmd)) >> shift;
 240 }
 241
 242 /*
 243  * The operations below are hints that tell the controller driver how
 244  * to handle I/Os with DIF or similar types of protection information.
 245  */
 246 enum scsi_prot_operations {
 247         /* Normal I/O */
 248         SCSI_PROT_NORMAL = 0,
 249
 250         /* OS-HBA: Protected, HBA-Target: Unprotected */
 251         SCSI_PROT_READ_INSERT,
 252         SCSI_PROT_WRITE_STRIP,
 253
 254         /* OS-HBA: Unprotected, HBA-Target: Protected */
 255         SCSI_PROT_READ_STRIP,
 256         SCSI_PROT_WRITE_INSERT,
 257
 258         /* OS-HBA: Protected, HBA-Target: Protected */
 259         SCSI_PROT_READ_PASS,
 260         SCSI_PROT_WRITE_PASS,
 261 };
 262
 263 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 264 {
 265         scmd->prot_op = op;
 266 }
 267
 268 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 269 {
 270         return scmd->prot_op;
 271 }
 272
 273 enum scsi_prot_flags {
 274         SCSI_PROT_TRANSFER_PI           = 1 << 0,
 275         SCSI_PROT_GUARD_CHECK           = 1 << 1,
 276         SCSI_PROT_REF_CHECK             = 1 << 2,
 277         SCSI_PROT_REF_INCREMENT         = 1 << 3,
 278         SCSI_PROT_IP_CHECKSUM           = 1 << 4,
 279 };
 280
 281 /*
 282  * The controller usually does not know anything about the target it
 283  * is communicating with.  However, when DIX is enabled the controller
 284  * must be know target type so it can verify the protection
 285  * information passed along with the I/O.
 286  */
 287 enum scsi_prot_target_type {
 288         SCSI_PROT_DIF_TYPE0 = 0,
 289         SCSI_PROT_DIF_TYPE1,
 290         SCSI_PROT_DIF_TYPE2,
 291         SCSI_PROT_DIF_TYPE3,
 292 };
 293
 294 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 295 {
 296         scmd->prot_type = type;
 297 }
 298
 299 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 300 {
 301         return scmd->prot_type;
 302 }
 303
 304 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
 305 {
 306         struct request *rq = blk_mq_rq_from_pdu(scmd);
 307
 308         return t10_pi_ref_tag(rq);
 309 }
 310
 311 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
 312 {
 313         return scmd->device->sector_size;
 314 }
 315
 316 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 317 {
 318         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 319 }
 320
 321 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 322 {
 323         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 324 }
 325
 326 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 327 {
 328         return cmd->prot_sdb;
 329 }
 330
 331 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 332         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 333
 334 static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
 335 {
 336         cmd->result = (cmd->result & 0xffffff00) | status;
 337 }
 338
 339 static inline u8 get_status_byte(struct scsi_cmnd *cmd)
 340 {
 341         return cmd->result & 0xff;
 342 }
 343
 344 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 345 {
 346         cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 347 }
 348
 349 static inline u8 get_host_byte(struct scsi_cmnd *cmd)
 350 {
 351         return (cmd->result >> 16) & 0xff;
 352 }
 353
 354 /**
 355  * scsi_msg_to_host_byte() - translate message byte
 356  * @cmd: the SCSI command
 357  * @msg: the SCSI parallel message byte to translate
 358  *
 359  * Translate the SCSI parallel message byte to a matching
 360  * host byte setting. A message of COMMAND_COMPLETE indicates
 361  * a successful command execution, any other message indicate
 362  * an error. As the messages themselves only have a meaning
 363  * for the SCSI parallel protocol this function translates
 364  * them into a matching host byte value for SCSI EH.
 365  */
 366 static inline void scsi_msg_to_host_byte(struct scsi_cmnd *cmd, u8 msg)
 367 {
 368         switch (msg) {
 369         case COMMAND_COMPLETE:
 370                 break;
 371         case ABORT_TASK_SET:
 372                 set_host_byte(cmd, DID_ABORT);
 373                 break;
 374         case TARGET_RESET:
 375                 set_host_byte(cmd, DID_RESET);
 376                 break;
 377         default:
 378                 set_host_byte(cmd, DID_ERROR);
 379                 break;
 380         }
 381 }
 382
 383 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 384 {
 385         unsigned int xfer_len = scmd->sdb.length;
 386         unsigned int prot_interval = scsi_prot_interval(scmd);
 387
 388         if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
 389                 xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
 390
 391         return xfer_len;
 392 }
 393
 394 extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
 395                              u8 key, u8 asc, u8 ascq);
 396
 397 struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf,
 398                                    blk_mq_req_flags_t flags);
 399
 400 #endif /* _SCSI_SCSI_CMND_H */