include/scsi/scsi_cmnd.h

   1 #ifndef _SCSI_SCSI_CMND_H
   2 #define _SCSI_SCSI_CMND_H
   3
   4 #include <linux/dma-mapping.h>
   5 #include <linux/blkdev.h>
   6 #include <linux/list.h>
   7 #include <linux/types.h>
   8 #include <linux/timer.h>
   9 #include <linux/scatterlist.h>
  10 #include <scsi/scsi_device.h>
  11 #include <scsi/scsi_request.h>
  12
  13 struct Scsi_Host;
  14 struct scsi_driver;
  15
  16 #include <scsi/scsi_device.h>
  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
  61 struct scsi_cmnd {
  62         struct scsi_request req;
  63         struct scsi_device *device;
  64         struct list_head list;  /* scsi_cmnd participates in queue lists */
  65         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  66         struct delayed_work abort_work;
  67         int eh_eflags;          /* Used by error handlr */
  68
  69         /*
  70          * A SCSI Command is assigned a nonzero serial_number before passed
  71          * to the driver's queue command function.  The serial_number is
  72          * cleared when scsi_done is entered indicating that the command
  73          * has been completed.  It is a bug for LLDDs to use this number
  74          * for purposes other than printk (and even that is only useful
  75          * for debugging).
  76          */
  77         unsigned long serial_number;
  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 #define SCSI_SENSE_BUFFERSIZE   96
 117         unsigned char *sense_buffer;
 118                                 /* obtained by REQUEST SENSE when
 119                                  * CHECK CONDITION is received on original
 120                                  * command (auto-sense) */
 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
 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 struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 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 int scsi_init_io(struct scsi_cmnd *cmd);
 170 extern void scsi_initialize_rq(struct request *rq);
 171
 172 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 173 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 174
 175 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 176 {
 177         return cmd->sdb.table.nents;
 178 }
 179
 180 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 181 {
 182         return cmd->sdb.table.sgl;
 183 }
 184
 185 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 186 {
 187         return cmd->sdb.length;
 188 }
 189
 190 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 191 {
 192         cmd->sdb.resid = resid;
 193 }
 194
 195 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 196 {
 197         return cmd->sdb.resid;
 198 }
 199
 200 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 201         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 202
 203 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
 204 {
 205         return blk_bidi_rq(cmd->request) &&
 206                 (cmd->request->next_rq->special != NULL);
 207 }
 208
 209 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
 210 {
 211         return scsi_bidi_cmnd(cmd) ?
 212                 cmd->request->next_rq->special : &cmd->sdb;
 213 }
 214
 215 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
 216 {
 217         return &cmd->sdb;
 218 }
 219
 220 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 221                                            void *buf, int buflen)
 222 {
 223         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 224                                    buf, buflen);
 225 }
 226
 227 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 228                                          void *buf, int buflen)
 229 {
 230         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 231                                  buf, buflen);
 232 }
 233
 234 /*
 235  * The operations below are hints that tell the controller driver how
 236  * to handle I/Os with DIF or similar types of protection information.
 237  */
 238 enum scsi_prot_operations {
 239         /* Normal I/O */
 240         SCSI_PROT_NORMAL = 0,
 241
 242         /* OS-HBA: Protected, HBA-Target: Unprotected */
 243         SCSI_PROT_READ_INSERT,
 244         SCSI_PROT_WRITE_STRIP,
 245
 246         /* OS-HBA: Unprotected, HBA-Target: Protected */
 247         SCSI_PROT_READ_STRIP,
 248         SCSI_PROT_WRITE_INSERT,
 249
 250         /* OS-HBA: Protected, HBA-Target: Protected */
 251         SCSI_PROT_READ_PASS,
 252         SCSI_PROT_WRITE_PASS,
 253 };
 254
 255 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 256 {
 257         scmd->prot_op = op;
 258 }
 259
 260 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 261 {
 262         return scmd->prot_op;
 263 }
 264
 265 enum scsi_prot_flags {
 266         SCSI_PROT_TRANSFER_PI           = 1 << 0,
 267         SCSI_PROT_GUARD_CHECK           = 1 << 1,
 268         SCSI_PROT_REF_CHECK             = 1 << 2,
 269         SCSI_PROT_REF_INCREMENT         = 1 << 3,
 270         SCSI_PROT_IP_CHECKSUM           = 1 << 4,
 271 };
 272
 273 /*
 274  * The controller usually does not know anything about the target it
 275  * is communicating with.  However, when DIX is enabled the controller
 276  * must be know target type so it can verify the protection
 277  * information passed along with the I/O.
 278  */
 279 enum scsi_prot_target_type {
 280         SCSI_PROT_DIF_TYPE0 = 0,
 281         SCSI_PROT_DIF_TYPE1,
 282         SCSI_PROT_DIF_TYPE2,
 283         SCSI_PROT_DIF_TYPE3,
 284 };
 285
 286 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 287 {
 288         scmd->prot_type = type;
 289 }
 290
 291 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 292 {
 293         return scmd->prot_type;
 294 }
 295
 296 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 297 {
 298         return blk_rq_pos(scmd->request);
 299 }
 300
 301 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
 302 {
 303         return scmd->device->sector_size;
 304 }
 305
 306 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
 307 {
 308         return blk_rq_pos(scmd->request) >>
 309                 (ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
 310 }
 311
 312 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 313 {
 314         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 315 }
 316
 317 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 318 {
 319         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 320 }
 321
 322 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 323 {
 324         return cmd->prot_sdb;
 325 }
 326
 327 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 328         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 329
 330 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
 331 {
 332         cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
 333 }
 334
 335 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 336 {
 337         cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 338 }
 339
 340 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 341 {
 342         cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
 343 }
 344
 345 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 346 {
 347         unsigned int xfer_len = scsi_out(scmd)->length;
 348         unsigned int prot_interval = scsi_prot_interval(scmd);
 349
 350         if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
 351                 xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
 352
 353         return xfer_len;
 354 }
 355
 356 #endif /* _SCSI_SCSI_CMND_H */