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