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
  60 struct scsi_cmnd {
  61         struct scsi_request req;
  62         struct scsi_device *device;
  63         struct list_head list;  /* scsi_cmnd participates in queue lists */
  64         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  65         struct delayed_work abort_work;
  66         int eh_eflags;          /* Used by error handlr */
  67
  68         /*
  69          * A SCSI Command is assigned a nonzero serial_number before passed
  70          * to the driver's queue command function.  The serial_number is
  71          * cleared when scsi_done is entered indicating that the command
  72          * has been completed.  It is a bug for LLDDs to use this number
  73          * for purposes other than printk (and even that is only useful
  74          * for debugging).
  75          */
  76         unsigned long serial_number;
  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 #define SCSI_SENSE_BUFFERSIZE   96
 116         unsigned char *sense_buffer;
 117                                 /* obtained by REQUEST SENSE when
 118                                  * CHECK CONDITION is received on original
 119                                  * command (auto-sense) */
 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
 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 struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 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 int scsi_init_io(struct scsi_cmnd *cmd);
 169
 170 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 171 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 172
 173 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 174 {
 175         return cmd->sdb.table.nents;
 176 }
 177
 178 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 179 {
 180         return cmd->sdb.table.sgl;
 181 }
 182
 183 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 184 {
 185         return cmd->sdb.length;
 186 }
 187
 188 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 189 {
 190         cmd->sdb.resid = resid;
 191 }
 192
 193 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 194 {
 195         return cmd->sdb.resid;
 196 }
 197
 198 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 199         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 200
 201 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
 202 {
 203         return blk_bidi_rq(cmd->request) &&
 204                 (cmd->request->next_rq->special != NULL);
 205 }
 206
 207 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
 208 {
 209         return scsi_bidi_cmnd(cmd) ?
 210                 cmd->request->next_rq->special : &cmd->sdb;
 211 }
 212
 213 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
 214 {
 215         return &cmd->sdb;
 216 }
 217
 218 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 219                                            void *buf, int buflen)
 220 {
 221         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 222                                    buf, buflen);
 223 }
 224
 225 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 226                                          void *buf, int buflen)
 227 {
 228         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 229                                  buf, buflen);
 230 }
 231
 232 /*
 233  * The operations below are hints that tell the controller driver how
 234  * to handle I/Os with DIF or similar types of protection information.
 235  */
 236 enum scsi_prot_operations {
 237         /* Normal I/O */
 238         SCSI_PROT_NORMAL = 0,
 239
 240         /* OS-HBA: Protected, HBA-Target: Unprotected */
 241         SCSI_PROT_READ_INSERT,
 242         SCSI_PROT_WRITE_STRIP,
 243
 244         /* OS-HBA: Unprotected, HBA-Target: Protected */
 245         SCSI_PROT_READ_STRIP,
 246         SCSI_PROT_WRITE_INSERT,
 247
 248         /* OS-HBA: Protected, HBA-Target: Protected */
 249         SCSI_PROT_READ_PASS,
 250         SCSI_PROT_WRITE_PASS,
 251 };
 252
 253 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 254 {
 255         scmd->prot_op = op;
 256 }
 257
 258 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 259 {
 260         return scmd->prot_op;
 261 }
 262
 263 enum scsi_prot_flags {
 264         SCSI_PROT_TRANSFER_PI           = 1 << 0,
 265         SCSI_PROT_GUARD_CHECK           = 1 << 1,
 266         SCSI_PROT_REF_CHECK             = 1 << 2,
 267         SCSI_PROT_REF_INCREMENT         = 1 << 3,
 268         SCSI_PROT_IP_CHECKSUM           = 1 << 4,
 269 };
 270
 271 /*
 272  * The controller usually does not know anything about the target it
 273  * is communicating with.  However, when DIX is enabled the controller
 274  * must be know target type so it can verify the protection
 275  * information passed along with the I/O.
 276  */
 277 enum scsi_prot_target_type {
 278         SCSI_PROT_DIF_TYPE0 = 0,
 279         SCSI_PROT_DIF_TYPE1,
 280         SCSI_PROT_DIF_TYPE2,
 281         SCSI_PROT_DIF_TYPE3,
 282 };
 283
 284 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 285 {
 286         scmd->prot_type = type;
 287 }
 288
 289 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 290 {
 291         return scmd->prot_type;
 292 }
 293
 294 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 295 {
 296         return blk_rq_pos(scmd->request);
 297 }
 298
 299 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
 300 {
 301         return scmd->device->sector_size;
 302 }
 303
 304 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
 305 {
 306         return blk_rq_pos(scmd->request) >>
 307                 (ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
 308 }
 309
 310 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 311 {
 312         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 313 }
 314
 315 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 316 {
 317         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 318 }
 319
 320 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 321 {
 322         return cmd->prot_sdb;
 323 }
 324
 325 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 326         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 327
 328 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
 329 {
 330         cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
 331 }
 332
 333 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 334 {
 335         cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 336 }
 337
 338 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 339 {
 340         cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
 341 }
 342
 343 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 344 {
 345         unsigned int xfer_len = scsi_out(scmd)->length;
 346         unsigned int prot_interval = scsi_prot_interval(scmd);
 347
 348         if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
 349                 xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
 350
 351         return xfer_len;
 352 }
 353
 354 #endif /* _SCSI_SCSI_CMND_H */