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         int eh_eflags;          /* Used by error handlr */
  73
  74         /*
  75          * A SCSI Command is assigned a nonzero serial_number before passed
  76          * to the driver's queue command function.  The serial_number is
  77          * cleared when scsi_done is entered indicating that the command
  78          * has been completed.  It is a bug for LLDDs to use this number
  79          * for purposes other than printk (and even that is only useful
  80          * for debugging).
  81          */
  82         unsigned long serial_number;
  83
  84         /*
  85          * This is set to jiffies as it was when the command was first
  86          * allocated.  It is used to time how long the command has
  87          * been outstanding
  88          */
  89         unsigned long jiffies_at_alloc;
  90
  91         int retries;
  92         int allowed;
  93
  94         unsigned char prot_op;
  95         unsigned char prot_type;
  96         unsigned char prot_flags;
  97
  98         unsigned short cmd_len;
  99         enum dma_data_direction sc_data_direction;
 100
 101         /* These elements define the operation we are about to perform */
 102         unsigned char *cmnd;
 103
 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
 118         struct request *request;        /* The command we are
 119                                            working on */
 120
 121 #define SCSI_SENSE_BUFFERSIZE   96
 122         unsigned char *sense_buffer;
 123                                 /* obtained by REQUEST SENSE when
 124                                  * CHECK CONDITION is received on original
 125                                  * command (auto-sense) */
 126
 127         /* Low-level done function - can be used by low-level driver to point
 128          *        to completion function.  Not used by mid/upper level code. */
 129         void (*scsi_done) (struct scsi_cmnd *);
 130
 131         /*
 132          * The following fields can be written to by the host specific code.
 133          * Everything else should be left alone.
 134          */
 135         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 136
 137         unsigned char *host_scribble;   /* The host adapter is allowed to
 138                                          * call scsi_malloc and get some memory
 139                                          * and hang it here.  The host adapter
 140                                          * is also expected to call scsi_free
 141                                          * to release this memory.  (The memory
 142                                          * obtained by scsi_malloc is guaranteed
 143                                          * to be at an address < 16Mb). */
 144
 145         int result;             /* Status code from lower level driver */
 146         int flags;              /* Command flags */
 147
 148         unsigned char tag;      /* SCSI-II queued command tag */
 149 };
 150
 151 /*
 152  * Return the driver private allocation behind the command.
 153  * Only works if cmd_size is set in the host template.
 154  */
 155 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
 156 {
 157         return cmd + 1;
 158 }
 159
 160 /* make sure not to use it with passthrough commands */
 161 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
 162 {
 163         return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
 164 }
 165
 166 extern void scsi_put_command(struct scsi_cmnd *);
 167 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 168
 169 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 170                                  size_t *offset, size_t *len);
 171 extern void scsi_kunmap_atomic_sg(void *virt);
 172
 173 extern int scsi_init_io(struct scsi_cmnd *cmd);
 174 extern void scsi_initialize_rq(struct request *rq);
 175
 176 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 177 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 178
 179 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 180 {
 181         return cmd->sdb.table.nents;
 182 }
 183
 184 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 185 {
 186         return cmd->sdb.table.sgl;
 187 }
 188
 189 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 190 {
 191         return cmd->sdb.length;
 192 }
 193
 194 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 195 {
 196         cmd->sdb.resid = resid;
 197 }
 198
 199 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 200 {
 201         return cmd->sdb.resid;
 202 }
 203
 204 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 205         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 206
 207 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
 208 {
 209         return blk_bidi_rq(cmd->request) &&
 210                 (cmd->request->next_rq->special != NULL);
 211 }
 212
 213 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
 214 {
 215         return scsi_bidi_cmnd(cmd) ?
 216                 cmd->request->next_rq->special : &cmd->sdb;
 217 }
 218
 219 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
 220 {
 221         return &cmd->sdb;
 222 }
 223
 224 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 225                                            void *buf, int buflen)
 226 {
 227         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 228                                    buf, buflen);
 229 }
 230
 231 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 232                                          void *buf, int buflen)
 233 {
 234         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 235                                  buf, buflen);
 236 }
 237
 238 /*
 239  * The operations below are hints that tell the controller driver how
 240  * to handle I/Os with DIF or similar types of protection information.
 241  */
 242 enum scsi_prot_operations {
 243         /* Normal I/O */
 244         SCSI_PROT_NORMAL = 0,
 245
 246         /* OS-HBA: Protected, HBA-Target: Unprotected */
 247         SCSI_PROT_READ_INSERT,
 248         SCSI_PROT_WRITE_STRIP,
 249
 250         /* OS-HBA: Unprotected, HBA-Target: Protected */
 251         SCSI_PROT_READ_STRIP,
 252         SCSI_PROT_WRITE_INSERT,
 253
 254         /* OS-HBA: Protected, HBA-Target: Protected */
 255         SCSI_PROT_READ_PASS,
 256         SCSI_PROT_WRITE_PASS,
 257 };
 258
 259 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 260 {
 261         scmd->prot_op = op;
 262 }
 263
 264 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 265 {
 266         return scmd->prot_op;
 267 }
 268
 269 enum scsi_prot_flags {
 270         SCSI_PROT_TRANSFER_PI           = 1 << 0,
 271         SCSI_PROT_GUARD_CHECK           = 1 << 1,
 272         SCSI_PROT_REF_CHECK             = 1 << 2,
 273         SCSI_PROT_REF_INCREMENT         = 1 << 3,
 274         SCSI_PROT_IP_CHECKSUM           = 1 << 4,
 275 };
 276
 277 /*
 278  * The controller usually does not know anything about the target it
 279  * is communicating with.  However, when DIX is enabled the controller
 280  * must be know target type so it can verify the protection
 281  * information passed along with the I/O.
 282  */
 283 enum scsi_prot_target_type {
 284         SCSI_PROT_DIF_TYPE0 = 0,
 285         SCSI_PROT_DIF_TYPE1,
 286         SCSI_PROT_DIF_TYPE2,
 287         SCSI_PROT_DIF_TYPE3,
 288 };
 289
 290 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 291 {
 292         scmd->prot_type = type;
 293 }
 294
 295 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 296 {
 297         return scmd->prot_type;
 298 }
 299
 300 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 301 {
 302         return blk_rq_pos(scmd->request);
 303 }
 304
 305 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
 306 {
 307         return scmd->device->sector_size;
 308 }
 309
 310 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
 311 {
 312         return blk_rq_pos(scmd->request) >>
 313                 (ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
 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_msg_byte(struct scsi_cmnd *cmd, char status)
 335 {
 336         cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
 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 void set_driver_byte(struct scsi_cmnd *cmd, char status)
 345 {
 346         cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
 347 }
 348
 349 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 350 {
 351         unsigned int xfer_len = scsi_out(scmd)->length;
 352         unsigned int prot_interval = scsi_prot_interval(scmd);
 353
 354         if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
 355                 xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
 356
 357         return xfer_len;
 358 }
 359
 360 #endif /* _SCSI_SCSI_CMND_H */