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 #include <scsi/scsi_request.h>
  14
  15 struct Scsi_Host;
  16 struct scsi_driver;
  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 };
  39
  40 /* embedded in scsi_cmnd */
  41 struct scsi_pointer {
  42         char *ptr;              /* data pointer */
  43         int this_residual;      /* left in this buffer */
  44         struct scatterlist *buffer;     /* which buffer */
  45         int buffers_residual;   /* how many buffers left */
  46
  47         dma_addr_t dma_handle;
  48
  49         volatile int Status;
  50         volatile int Message;
  51         volatile int have_data_in;
  52         volatile int sent_command;
  53         volatile int phase;
  54 };
  55
  56 /* for scmd->flags */
  57 #define SCMD_TAGGED             (1 << 0)
  58 #define SCMD_UNCHECKED_ISA_DMA  (1 << 1)
  59 #define SCMD_INITIALIZED        (1 << 2)
  60 #define SCMD_LAST               (1 << 3)
  61 /* flags preserved across unprep / reprep */
  62 #define SCMD_PRESERVED_FLAGS    (SCMD_UNCHECKED_ISA_DMA | SCMD_INITIALIZED)
  63
  64 /* for scmd->state */
  65 #define SCMD_STATE_COMPLETE     0
  66 #define SCMD_STATE_INFLIGHT     1
  67
  68 struct scsi_cmnd {
  69         struct scsi_request req;
  70         struct scsi_device *device;
  71         struct list_head list;  /* scsi_cmnd participates in queue lists */
  72         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  73         struct delayed_work abort_work;
  74
  75         struct rcu_head rcu;
  76
  77         int eh_eflags;          /* Used by error handlr */
  78
  79         /*
  80          * This is set to jiffies as it was when the command was first
  81          * allocated.  It is used to time how long the command has
  82          * been outstanding
  83          */
  84         unsigned long jiffies_at_alloc;
  85
  86         int retries;
  87         int allowed;
  88
  89         unsigned char prot_op;
  90         unsigned char prot_type;
  91         unsigned char prot_flags;
  92
  93         unsigned short cmd_len;
  94         enum dma_data_direction sc_data_direction;
  95
  96         /* These elements define the operation we are about to perform */
  97         unsigned char *cmnd;
  98
  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
 113         struct request *request;        /* The command we are
 114                                            working on */
 115
 116         unsigned char *sense_buffer;
 117                                 /* obtained by REQUEST SENSE when
 118                                  * CHECK CONDITION is received on original
 119                                  * command (auto-sense). Length must be
 120                                  * SCSI_SENSE_BUFFERSIZE bytes. */
 121
 122         /* Low-level done function - can be used by low-level driver to point
 123          *        to completion function.  Not used by mid/upper level code. */
 124         void (*scsi_done) (struct scsi_cmnd *);
 125
 126         /*
 127          * The following fields can be written to by the host specific code.
 128          * Everything else should be left alone.
 129          */
 130         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 131
 132         unsigned char *host_scribble;   /* The host adapter is allowed to
 133                                          * call scsi_malloc and get some memory
 134                                          * and hang it here.  The host adapter
 135                                          * is also expected to call scsi_free
 136                                          * to release this memory.  (The memory
 137                                          * obtained by scsi_malloc is guaranteed
 138                                          * to be at an address < 16Mb). */
 139
 140         int result;             /* Status code from lower level driver */
 141         int flags;              /* Command flags */
 142         unsigned long state;    /* Command completion state */
 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 void scsi_put_command(struct scsi_cmnd *);
 163 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 164
 165 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 166                                  size_t *offset, size_t *len);
 167 extern void scsi_kunmap_atomic_sg(void *virt);
 168
 169 extern blk_status_t scsi_init_io(struct scsi_cmnd *cmd);
 170
 171 #ifdef CONFIG_SCSI_DMA
 172 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 173 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 174 #else /* !CONFIG_SCSI_DMA */
 175 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
 176 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
 177 #endif /* !CONFIG_SCSI_DMA */
 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, unsigned int resid)
 195 {
 196         cmd->req.resid_len = resid;
 197 }
 198
 199 static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
 200 {
 201         return cmd->req.resid_len;
 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_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 208                                            void *buf, int buflen)
 209 {
 210         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 211                                    buf, buflen);
 212 }
 213
 214 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 215                                          void *buf, int buflen)
 216 {
 217         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 218                                  buf, buflen);
 219 }
 220
 221 /*
 222  * The operations below are hints that tell the controller driver how
 223  * to handle I/Os with DIF or similar types of protection information.
 224  */
 225 enum scsi_prot_operations {
 226         /* Normal I/O */
 227         SCSI_PROT_NORMAL = 0,
 228
 229         /* OS-HBA: Protected, HBA-Target: Unprotected */
 230         SCSI_PROT_READ_INSERT,
 231         SCSI_PROT_WRITE_STRIP,
 232
 233         /* OS-HBA: Unprotected, HBA-Target: Protected */
 234         SCSI_PROT_READ_STRIP,
 235         SCSI_PROT_WRITE_INSERT,
 236
 237         /* OS-HBA: Protected, HBA-Target: Protected */
 238         SCSI_PROT_READ_PASS,
 239         SCSI_PROT_WRITE_PASS,
 240 };
 241
 242 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 243 {
 244         scmd->prot_op = op;
 245 }
 246
 247 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 248 {
 249         return scmd->prot_op;
 250 }
 251
 252 enum scsi_prot_flags {
 253         SCSI_PROT_TRANSFER_PI           = 1 << 0,
 254         SCSI_PROT_GUARD_CHECK           = 1 << 1,
 255         SCSI_PROT_REF_CHECK             = 1 << 2,
 256         SCSI_PROT_REF_INCREMENT         = 1 << 3,
 257         SCSI_PROT_IP_CHECKSUM           = 1 << 4,
 258 };
 259
 260 /*
 261  * The controller usually does not know anything about the target it
 262  * is communicating with.  However, when DIX is enabled the controller
 263  * must be know target type so it can verify the protection
 264  * information passed along with the I/O.
 265  */
 266 enum scsi_prot_target_type {
 267         SCSI_PROT_DIF_TYPE0 = 0,
 268         SCSI_PROT_DIF_TYPE1,
 269         SCSI_PROT_DIF_TYPE2,
 270         SCSI_PROT_DIF_TYPE3,
 271 };
 272
 273 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 274 {
 275         scmd->prot_type = type;
 276 }
 277
 278 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 279 {
 280         return scmd->prot_type;
 281 }
 282
 283 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 284 {
 285         return blk_rq_pos(scmd->request);
 286 }
 287
 288 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
 289 {
 290         return scmd->device->sector_size;
 291 }
 292
 293 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 294 {
 295         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 296 }
 297
 298 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 299 {
 300         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 301 }
 302
 303 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 304 {
 305         return cmd->prot_sdb;
 306 }
 307
 308 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 309         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 310
 311 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
 312 {
 313         cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
 314 }
 315
 316 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 317 {
 318         cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 319 }
 320
 321 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 322 {
 323         cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
 324 }
 325
 326 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 327 {
 328         unsigned int xfer_len = scmd->sdb.length;
 329         unsigned int prot_interval = scsi_prot_interval(scmd);
 330
 331         if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
 332                 xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
 333
 334         return xfer_len;
 335 }
 336
 337 #endif /* _SCSI_SCSI_CMND_H */