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 /* flags preserved across unprep / reprep */
  61 #define SCMD_PRESERVED_FLAGS    (SCMD_UNCHECKED_ISA_DMA | SCMD_INITIALIZED)
  62
  63 /* for scmd->state */
  64 #define SCMD_STATE_COMPLETE     0
  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          * This is set to jiffies as it was when the command was first
  79          * allocated.  It is used to time how long the command has
  80          * been outstanding
  81          */
  82         unsigned long jiffies_at_alloc;
  83
  84         int retries;
  85         int allowed;
  86
  87         unsigned char prot_op;
  88         unsigned char prot_type;
  89         unsigned char prot_flags;
  90
  91         unsigned short cmd_len;
  92         enum dma_data_direction sc_data_direction;
  93
  94         /* These elements define the operation we are about to perform */
  95         unsigned char *cmnd;
  96
  97
  98         /* These elements define the operation we ultimately want to perform */
  99         struct scsi_data_buffer sdb;
 100         struct scsi_data_buffer *prot_sdb;
 101
 102         unsigned underflow;     /* Return error if less than
 103                                    this amount is transferred */
 104
 105         unsigned transfersize;  /* How much we are guaranteed to
 106                                    transfer with each SCSI transfer
 107                                    (ie, between disconnect /
 108                                    reconnects.   Probably == sector
 109                                    size */
 110
 111         struct request *request;        /* The command we are
 112                                            working on */
 113
 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         /* Low-level done function - can be used by low-level driver to point
 121          *        to completion function.  Not used by mid/upper level code. */
 122         void (*scsi_done) (struct scsi_cmnd *);
 123
 124         /*
 125          * The following fields can be written to by the host specific code.
 126          * Everything else should be left alone.
 127          */
 128         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 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         int flags;              /* Command flags */
 140         unsigned long state;    /* Command completion state */
 141
 142         unsigned char tag;      /* SCSI-II queued command tag */
 143 };
 144
 145 /*
 146  * Return the driver private allocation behind the command.
 147  * Only works if cmd_size is set in the host template.
 148  */
 149 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
 150 {
 151         return cmd + 1;
 152 }
 153
 154 /* make sure not to use it with passthrough commands */
 155 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
 156 {
 157         return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
 158 }
 159
 160 extern void scsi_put_command(struct scsi_cmnd *);
 161 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 162
 163 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 164                                  size_t *offset, size_t *len);
 165 extern void scsi_kunmap_atomic_sg(void *virt);
 166
 167 extern blk_status_t scsi_init_io(struct scsi_cmnd *cmd);
 168
 169 #ifdef CONFIG_SCSI_DMA
 170 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 171 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 172 #else /* !CONFIG_SCSI_DMA */
 173 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
 174 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
 175 #endif /* !CONFIG_SCSI_DMA */
 176
 177 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 178 {
 179         return cmd->sdb.table.nents;
 180 }
 181
 182 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 183 {
 184         return cmd->sdb.table.sgl;
 185 }
 186
 187 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 188 {
 189         return cmd->sdb.length;
 190 }
 191
 192 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 193 {
 194         cmd->req.resid_len = resid;
 195 }
 196
 197 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 198 {
 199         return cmd->req.resid_len;
 200 }
 201
 202 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 203         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 204
 205 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 206                                            void *buf, int buflen)
 207 {
 208         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 209                                    buf, buflen);
 210 }
 211
 212 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 213                                          void *buf, int buflen)
 214 {
 215         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 216                                  buf, buflen);
 217 }
 218
 219 /*
 220  * The operations below are hints that tell the controller driver how
 221  * to handle I/Os with DIF or similar types of protection information.
 222  */
 223 enum scsi_prot_operations {
 224         /* Normal I/O */
 225         SCSI_PROT_NORMAL = 0,
 226
 227         /* OS-HBA: Protected, HBA-Target: Unprotected */
 228         SCSI_PROT_READ_INSERT,
 229         SCSI_PROT_WRITE_STRIP,
 230
 231         /* OS-HBA: Unprotected, HBA-Target: Protected */
 232         SCSI_PROT_READ_STRIP,
 233         SCSI_PROT_WRITE_INSERT,
 234
 235         /* OS-HBA: Protected, HBA-Target: Protected */
 236         SCSI_PROT_READ_PASS,
 237         SCSI_PROT_WRITE_PASS,
 238 };
 239
 240 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 241 {
 242         scmd->prot_op = op;
 243 }
 244
 245 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 246 {
 247         return scmd->prot_op;
 248 }
 249
 250 enum scsi_prot_flags {
 251         SCSI_PROT_TRANSFER_PI           = 1 << 0,
 252         SCSI_PROT_GUARD_CHECK           = 1 << 1,
 253         SCSI_PROT_REF_CHECK             = 1 << 2,
 254         SCSI_PROT_REF_INCREMENT         = 1 << 3,
 255         SCSI_PROT_IP_CHECKSUM           = 1 << 4,
 256 };
 257
 258 /*
 259  * The controller usually does not know anything about the target it
 260  * is communicating with.  However, when DIX is enabled the controller
 261  * must be know target type so it can verify the protection
 262  * information passed along with the I/O.
 263  */
 264 enum scsi_prot_target_type {
 265         SCSI_PROT_DIF_TYPE0 = 0,
 266         SCSI_PROT_DIF_TYPE1,
 267         SCSI_PROT_DIF_TYPE2,
 268         SCSI_PROT_DIF_TYPE3,
 269 };
 270
 271 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 272 {
 273         scmd->prot_type = type;
 274 }
 275
 276 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 277 {
 278         return scmd->prot_type;
 279 }
 280
 281 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 282 {
 283         return blk_rq_pos(scmd->request);
 284 }
 285
 286 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
 287 {
 288         return scmd->device->sector_size;
 289 }
 290
 291 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 292 {
 293         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 294 }
 295
 296 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 297 {
 298         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 299 }
 300
 301 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 302 {
 303         return cmd->prot_sdb;
 304 }
 305
 306 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 307         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 308
 309 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
 310 {
 311         cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
 312 }
 313
 314 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 315 {
 316         cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 317 }
 318
 319 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 320 {
 321         cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
 322 }
 323
 324 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 325 {
 326         unsigned int xfer_len = scmd->sdb.length;
 327         unsigned int prot_interval = scsi_prot_interval(scmd);
 328
 329         if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
 330                 xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
 331
 332         return xfer_len;
 333 }
 334
 335 #endif /* _SCSI_SCSI_CMND_H */