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