root/include/scsi/scsi_cmnd.h

INCLUDED FROM

DEFINITIONS

1. scsi_cmd_priv
2. scsi_cmd_to_driver
3. scsi_dma_map
4. scsi_dma_unmap
5. scsi_sg_count
6. scsi_sglist
7. scsi_bufflen
8. scsi_set_resid
9. scsi_get_resid
10. scsi_sg_copy_from_buffer
11. scsi_sg_copy_to_buffer
12. scsi_set_prot_op
13. scsi_get_prot_op
14. scsi_set_prot_type
15. scsi_get_prot_type
16. scsi_get_lba
17. scsi_prot_interval
18. scsi_prot_sg_count
19. scsi_prot_sglist
20. scsi_prot
21. set_msg_byte
22. set_host_byte
23. set_driver_byte
24. scsi_transfer_length

   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 
  67 struct scsi_cmnd {
  68         struct scsi_request req;
  69         struct scsi_device *device;
  70         struct list_head list;  /* scsi_cmnd participates in queue lists */
  71         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  72         struct delayed_work abort_work;
  73 
  74         struct rcu_head rcu;
  75 
  76         int eh_eflags;          /* Used by error handlr */
  77 
  78         /*
  79          * This is set to jiffies as it was when the command was first
  80          * allocated.  It is used to time how long the command has
  81          * been outstanding
  82          */
  83         unsigned long jiffies_at_alloc;
  84 
  85         int retries;
  86         int allowed;
  87 
  88         unsigned char prot_op;
  89         unsigned char prot_type;
  90         unsigned char prot_flags;
  91 
  92         unsigned short cmd_len;
  93         enum dma_data_direction sc_data_direction;
  94 
  95         /* These elements define the operation we are about to perform */
  96         unsigned char *cmnd;
  97 
  98 
  99         /* These elements define the operation we ultimately want to perform */
 100         struct scsi_data_buffer sdb;
 101         struct scsi_data_buffer *prot_sdb;
 102 
 103         unsigned underflow;     /* Return error if less than
 104                                    this amount is transferred */
 105 
 106         unsigned transfersize;  /* How much we are guaranteed to
 107                                    transfer with each SCSI transfer
 108                                    (ie, between disconnect / 
 109                                    reconnects.   Probably == sector
 110                                    size */
 111 
 112         struct request *request;        /* The command we are
 113                                            working on */
 114 
 115         unsigned char *sense_buffer;
 116                                 /* obtained by REQUEST SENSE when
 117                                  * CHECK CONDITION is received on original
 118                                  * command (auto-sense). Length must be
 119                                  * SCSI_SENSE_BUFFERSIZE bytes. */
 120 
 121         /* Low-level done function - can be used by low-level driver to point
 122          *        to completion function.  Not used by mid/upper level code. */
 123         void (*scsi_done) (struct scsi_cmnd *);
 124 
 125         /*
 126          * The following fields can be written to by the host specific code. 
 127          * Everything else should be left alone. 
 128          */
 129         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 130 
 131         unsigned char *host_scribble;   /* The host adapter is allowed to
 132                                          * call scsi_malloc and get some memory
 133                                          * and hang it here.  The host adapter
 134                                          * is also expected to call scsi_free
 135                                          * to release this memory.  (The memory
 136                                          * obtained by scsi_malloc is guaranteed
 137                                          * to be at an address < 16Mb). */
 138 
 139         int result;             /* Status code from lower level driver */
 140         int flags;              /* Command flags */
 141         unsigned long state;    /* Command completion state */
 142 
 143         unsigned char tag;      /* SCSI-II queued command tag */
 144 };
 145 
 146 /*
 147  * Return the driver private allocation behind the command.
 148  * Only works if cmd_size is set in the host template.
 149  */
 150 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
 151 {
 152         return cmd + 1;
 153 }
 154 
 155 /* make sure not to use it with passthrough commands */
 156 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
 157 {
 158         return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
 159 }
 160 
 161 extern void scsi_put_command(struct scsi_cmnd *);
 162 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 163 
 164 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 165                                  size_t *offset, size_t *len);
 166 extern void scsi_kunmap_atomic_sg(void *virt);
 167 
 168 extern blk_status_t scsi_init_io(struct scsi_cmnd *cmd);
 169 
 170 #ifdef CONFIG_SCSI_DMA
 171 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 172 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 173 #else /* !CONFIG_SCSI_DMA */
 174 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
 175 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
 176 #endif /* !CONFIG_SCSI_DMA */
 177 
 178 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 179 {
 180         return cmd->sdb.table.nents;
 181 }
 182 
 183 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 184 {
 185         return cmd->sdb.table.sgl;
 186 }
 187 
 188 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 189 {
 190         return cmd->sdb.length;
 191 }
 192 
 193 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 194 {
 195         cmd->req.resid_len = resid;
 196 }
 197 
 198 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 199 {
 200         return cmd->req.resid_len;
 201 }
 202 
 203 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 204         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 205 
 206 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 207                                            void *buf, int buflen)
 208 {
 209         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 210                                    buf, buflen);
 211 }
 212 
 213 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 214                                          void *buf, int buflen)
 215 {
 216         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 217                                  buf, buflen);
 218 }
 219 
 220 /*
 221  * The operations below are hints that tell the controller driver how
 222  * to handle I/Os with DIF or similar types of protection information.
 223  */
 224 enum scsi_prot_operations {
 225         /* Normal I/O */
 226         SCSI_PROT_NORMAL = 0,
 227 
 228         /* OS-HBA: Protected, HBA-Target: Unprotected */
 229         SCSI_PROT_READ_INSERT,
 230         SCSI_PROT_WRITE_STRIP,
 231 
 232         /* OS-HBA: Unprotected, HBA-Target: Protected */
 233         SCSI_PROT_READ_STRIP,
 234         SCSI_PROT_WRITE_INSERT,
 235 
 236         /* OS-HBA: Protected, HBA-Target: Protected */
 237         SCSI_PROT_READ_PASS,
 238         SCSI_PROT_WRITE_PASS,
 239 };
 240 
 241 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 242 {
 243         scmd->prot_op = op;
 244 }
 245 
 246 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 247 {
 248         return scmd->prot_op;
 249 }
 250 
 251 enum scsi_prot_flags {
 252         SCSI_PROT_TRANSFER_PI           = 1 << 0,
 253         SCSI_PROT_GUARD_CHECK           = 1 << 1,
 254         SCSI_PROT_REF_CHECK             = 1 << 2,
 255         SCSI_PROT_REF_INCREMENT         = 1 << 3,
 256         SCSI_PROT_IP_CHECKSUM           = 1 << 4,
 257 };
 258 
 259 /*
 260  * The controller usually does not know anything about the target it
 261  * is communicating with.  However, when DIX is enabled the controller
 262  * must be know target type so it can verify the protection
 263  * information passed along with the I/O.
 264  */
 265 enum scsi_prot_target_type {
 266         SCSI_PROT_DIF_TYPE0 = 0,
 267         SCSI_PROT_DIF_TYPE1,
 268         SCSI_PROT_DIF_TYPE2,
 269         SCSI_PROT_DIF_TYPE3,
 270 };
 271 
 272 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 273 {
 274         scmd->prot_type = type;
 275 }
 276 
 277 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 278 {
 279         return scmd->prot_type;
 280 }
 281 
 282 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 283 {
 284         return blk_rq_pos(scmd->request);
 285 }
 286 
 287 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
 288 {
 289         return scmd->device->sector_size;
 290 }
 291 
 292 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 293 {
 294         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 295 }
 296 
 297 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 298 {
 299         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 300 }
 301 
 302 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 303 {
 304         return cmd->prot_sdb;
 305 }
 306 
 307 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 308         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 309 
 310 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
 311 {
 312         cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
 313 }
 314 
 315 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 316 {
 317         cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 318 }
 319 
 320 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 321 {
 322         cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
 323 }
 324 
 325 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 326 {
 327         unsigned int xfer_len = scmd->sdb.length;
 328         unsigned int prot_interval = scsi_prot_interval(scmd);
 329 
 330         if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
 331                 xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
 332 
 333         return xfer_len;
 334 }
 335 
 336 #endif /* _SCSI_SCSI_CMND_H */