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/list.h>
   8 #include <linux/types.h>
   9 #include <linux/timer.h>
  10 #include <linux/scatterlist.h>
  11 #include <scsi/scsi_device.h>
  12 #include <scsi/scsi_request.h>
  13
  14 struct Scsi_Host;
  15 struct scsi_driver;
  16
  17 #include <scsi/scsi_device.h>
  18
  19 /*
  20  * MAX_COMMAND_SIZE is:
  21  * The longest fixed-length SCSI CDB as per the SCSI standard.
  22  * fixed-length means: commands that their size can be determined
  23  * by their opcode and the CDB does not carry a length specifier, (unlike
  24  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
  25  * true and the SCSI standard also defines extended commands and
  26  * vendor specific commands that can be bigger than 16 bytes. The kernel
  27  * will support these using the same infrastructure used for VARLEN CDB's.
  28  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
  29  * supports without specifying a cmd_len by ULD's
  30  */
  31 #define MAX_COMMAND_SIZE 16
  32 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
  33 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
  34 #endif
  35
  36 struct scsi_data_buffer {
  37         struct sg_table table;
  38         unsigned length;
  39         int resid;
  40 };
  41
  42 /* embedded in scsi_cmnd */
  43 struct scsi_pointer {
  44         char *ptr;              /* data pointer */
  45         int this_residual;      /* left in this buffer */
  46         struct scatterlist *buffer;     /* which buffer */
  47         int buffers_residual;   /* how many buffers left */
  48
  49         dma_addr_t dma_handle;
  50
  51         volatile int Status;
  52         volatile int Message;
  53         volatile int have_data_in;
  54         volatile int sent_command;
  55         volatile int phase;
  56 };
  57
  58 /* for scmd->flags */
  59 #define SCMD_TAGGED             (1 << 0)
  60 #define SCMD_UNCHECKED_ISA_DMA  (1 << 1)
  61 #define SCMD_ZONE_WRITE_LOCK    (1 << 2)
  62 #define SCMD_INITIALIZED        (1 << 3)
  63 /* flags preserved across unprep / reprep */
  64 #define SCMD_PRESERVED_FLAGS    (SCMD_UNCHECKED_ISA_DMA | SCMD_INITIALIZED)
  65
  66 struct scsi_cmnd {
  67         struct scsi_request req;
  68         struct scsi_device *device;
  69         struct list_head list;  /* scsi_cmnd participates in queue lists */
  70         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  71         struct delayed_work abort_work;
  72
  73         struct rcu_head rcu;
  74
  75         int eh_eflags;          /* Used by error handlr */
  76
  77         /*
  78          * A SCSI Command is assigned a nonzero serial_number before passed
  79          * to the driver's queue command function.  The serial_number is
  80          * cleared when scsi_done is entered indicating that the command
  81          * has been completed.  It is a bug for LLDDs to use this number
  82          * for purposes other than printk (and even that is only useful
  83          * for debugging).
  84          */
  85         unsigned long serial_number;
  86
  87         /*
  88          * This is set to jiffies as it was when the command was first
  89          * allocated.  It is used to time how long the command has
  90          * been outstanding
  91          */
  92         unsigned long jiffies_at_alloc;
  93
  94         int retries;
  95         int allowed;
  96
  97         unsigned char prot_op;
  98         unsigned char prot_type;
  99         unsigned char prot_flags;
 100
 101         unsigned short cmd_len;
 102         enum dma_data_direction sc_data_direction;
 103
 104         /* These elements define the operation we are about to perform */
 105         unsigned char *cmnd;
 106
 107
 108         /* These elements define the operation we ultimately want to perform */
 109         struct scsi_data_buffer sdb;
 110         struct scsi_data_buffer *prot_sdb;
 111
 112         unsigned underflow;     /* Return error if less than
 113                                    this amount is transferred */
 114
 115         unsigned transfersize;  /* How much we are guaranteed to
 116                                    transfer with each SCSI transfer
 117                                    (ie, between disconnect /
 118                                    reconnects.   Probably == sector
 119                                    size */
 120
 121         struct request *request;        /* The command we are
 122                                            working on */
 123
 124 #define SCSI_SENSE_BUFFERSIZE   96
 125         unsigned char *sense_buffer;
 126                                 /* obtained by REQUEST SENSE when
 127                                  * CHECK CONDITION is received on original
 128                                  * command (auto-sense) */
 129
 130         /* Low-level done function - can be used by low-level driver to point
 131          *        to completion function.  Not used by mid/upper level code. */
 132         void (*scsi_done) (struct scsi_cmnd *);
 133
 134         /*
 135          * The following fields can be written to by the host specific code.
 136          * Everything else should be left alone.
 137          */
 138         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 139
 140         unsigned char *host_scribble;   /* The host adapter is allowed to
 141                                          * call scsi_malloc and get some memory
 142                                          * and hang it here.  The host adapter
 143                                          * is also expected to call scsi_free
 144                                          * to release this memory.  (The memory
 145                                          * obtained by scsi_malloc is guaranteed
 146                                          * to be at an address < 16Mb). */
 147
 148         int result;             /* Status code from lower level driver */
 149         int flags;              /* Command flags */
 150
 151         unsigned char tag;      /* SCSI-II queued command tag */
 152 };
 153
 154 /*
 155  * Return the driver private allocation behind the command.
 156  * Only works if cmd_size is set in the host template.
 157  */
 158 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
 159 {
 160         return cmd + 1;
 161 }
 162
 163 /* make sure not to use it with passthrough commands */
 164 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
 165 {
 166         return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
 167 }
 168
 169 extern void scsi_put_command(struct scsi_cmnd *);
 170 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 171
 172 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 173                                  size_t *offset, size_t *len);
 174 extern void scsi_kunmap_atomic_sg(void *virt);
 175
 176 extern int scsi_init_io(struct scsi_cmnd *cmd);
 177 extern void scsi_initialize_rq(struct request *rq);
 178
 179 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 180 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 181
 182 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 183 {
 184         return cmd->sdb.table.nents;
 185 }
 186
 187 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 188 {
 189         return cmd->sdb.table.sgl;
 190 }
 191
 192 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 193 {
 194         return cmd->sdb.length;
 195 }
 196
 197 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 198 {
 199         cmd->sdb.resid = resid;
 200 }
 201
 202 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 203 {
 204         return cmd->sdb.resid;
 205 }
 206
 207 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 208         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 209
 210 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
 211 {
 212         return blk_bidi_rq(cmd->request) &&
 213                 (cmd->request->next_rq->special != NULL);
 214 }
 215
 216 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
 217 {
 218         return scsi_bidi_cmnd(cmd) ?
 219                 cmd->request->next_rq->special : &cmd->sdb;
 220 }
 221
 222 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
 223 {
 224         return &cmd->sdb;
 225 }
 226
 227 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 228                                            void *buf, int buflen)
 229 {
 230         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 231                                    buf, buflen);
 232 }
 233
 234 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 235                                          void *buf, int buflen)
 236 {
 237         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 238                                  buf, buflen);
 239 }
 240
 241 /*
 242  * The operations below are hints that tell the controller driver how
 243  * to handle I/Os with DIF or similar types of protection information.
 244  */
 245 enum scsi_prot_operations {
 246         /* Normal I/O */
 247         SCSI_PROT_NORMAL = 0,
 248
 249         /* OS-HBA: Protected, HBA-Target: Unprotected */
 250         SCSI_PROT_READ_INSERT,
 251         SCSI_PROT_WRITE_STRIP,
 252
 253         /* OS-HBA: Unprotected, HBA-Target: Protected */
 254         SCSI_PROT_READ_STRIP,
 255         SCSI_PROT_WRITE_INSERT,
 256
 257         /* OS-HBA: Protected, HBA-Target: Protected */
 258         SCSI_PROT_READ_PASS,
 259         SCSI_PROT_WRITE_PASS,
 260 };
 261
 262 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 263 {
 264         scmd->prot_op = op;
 265 }
 266
 267 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 268 {
 269         return scmd->prot_op;
 270 }
 271
 272 enum scsi_prot_flags {
 273         SCSI_PROT_TRANSFER_PI           = 1 << 0,
 274         SCSI_PROT_GUARD_CHECK           = 1 << 1,
 275         SCSI_PROT_REF_CHECK             = 1 << 2,
 276         SCSI_PROT_REF_INCREMENT         = 1 << 3,
 277         SCSI_PROT_IP_CHECKSUM           = 1 << 4,
 278 };
 279
 280 /*
 281  * The controller usually does not know anything about the target it
 282  * is communicating with.  However, when DIX is enabled the controller
 283  * must be know target type so it can verify the protection
 284  * information passed along with the I/O.
 285  */
 286 enum scsi_prot_target_type {
 287         SCSI_PROT_DIF_TYPE0 = 0,
 288         SCSI_PROT_DIF_TYPE1,
 289         SCSI_PROT_DIF_TYPE2,
 290         SCSI_PROT_DIF_TYPE3,
 291 };
 292
 293 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 294 {
 295         scmd->prot_type = type;
 296 }
 297
 298 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 299 {
 300         return scmd->prot_type;
 301 }
 302
 303 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 304 {
 305         return blk_rq_pos(scmd->request);
 306 }
 307
 308 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
 309 {
 310         return scmd->device->sector_size;
 311 }
 312
 313 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
 314 {
 315         return blk_rq_pos(scmd->request) >>
 316                 (ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
 317 }
 318
 319 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 320 {
 321         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 322 }
 323
 324 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 325 {
 326         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 327 }
 328
 329 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 330 {
 331         return cmd->prot_sdb;
 332 }
 333
 334 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 335         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 336
 337 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
 338 {
 339         cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
 340 }
 341
 342 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 343 {
 344         cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 345 }
 346
 347 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 348 {
 349         cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
 350 }
 351
 352 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 353 {
 354         unsigned int xfer_len = scsi_out(scmd)->length;
 355         unsigned int prot_interval = scsi_prot_interval(scmd);
 356
 357         if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
 358                 xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
 359
 360         return xfer_len;
 361 }
 362
 363 #endif /* _SCSI_SCSI_CMND_H */