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
  12 struct Scsi_Host;
  13 struct scsi_driver;
  14
  15 #include <scsi/scsi_device.h>
  16
  17 /*
  18  * MAX_COMMAND_SIZE is:
  19  * The longest fixed-length SCSI CDB as per the SCSI standard.
  20  * fixed-length means: commands that their size can be determined
  21  * by their opcode and the CDB does not carry a length specifier, (unlike
  22  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
  23  * true and the SCSI standard also defines extended commands and
  24  * vendor specific commands that can be bigger than 16 bytes. The kernel
  25  * will support these using the same infrastructure used for VARLEN CDB's.
  26  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
  27  * supports without specifying a cmd_len by ULD's
  28  */
  29 #define MAX_COMMAND_SIZE 16
  30 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
  31 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
  32 #endif
  33
  34 struct scsi_data_buffer {
  35         struct sg_table table;
  36         unsigned length;
  37         int resid;
  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
  59 struct scsi_cmnd {
  60         struct scsi_device *device;
  61         struct list_head list;  /* scsi_cmnd participates in queue lists */
  62         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  63         struct delayed_work abort_work;
  64         int eh_eflags;          /* Used by error handlr */
  65
  66         /*
  67          * A SCSI Command is assigned a nonzero serial_number before passed
  68          * to the driver's queue command function.  The serial_number is
  69          * cleared when scsi_done is entered indicating that the command
  70          * has been completed.  It is a bug for LLDDs to use this number
  71          * for purposes other than printk (and even that is only useful
  72          * for debugging).
  73          */
  74         unsigned long serial_number;
  75
  76         /*
  77          * This is set to jiffies as it was when the command was first
  78          * allocated.  It is used to time how long the command has
  79          * been outstanding
  80          */
  81         unsigned long jiffies_at_alloc;
  82
  83         int retries;
  84         int allowed;
  85
  86         unsigned char prot_op;
  87         unsigned char prot_type;
  88         unsigned char prot_flags;
  89
  90         unsigned short cmd_len;
  91         enum dma_data_direction sc_data_direction;
  92
  93         /* These elements define the operation we are about to perform */
  94         unsigned char *cmnd;
  95
  96
  97         /* These elements define the operation we ultimately want to perform */
  98         struct scsi_data_buffer sdb;
  99         struct scsi_data_buffer *prot_sdb;
 100
 101         unsigned underflow;     /* Return error if less than
 102                                    this amount is transferred */
 103
 104         unsigned transfersize;  /* How much we are guaranteed to
 105                                    transfer with each SCSI transfer
 106                                    (ie, between disconnect /
 107                                    reconnects.   Probably == sector
 108                                    size */
 109
 110         struct request *request;        /* The command we are
 111                                            working on */
 112
 113 #define SCSI_SENSE_BUFFERSIZE   96
 114         unsigned char *sense_buffer;
 115                                 /* obtained by REQUEST SENSE when
 116                                  * CHECK CONDITION is received on original
 117                                  * command (auto-sense) */
 118
 119         /* Low-level done function - can be used by low-level driver to point
 120          *        to completion function.  Not used by mid/upper level code. */
 121         void (*scsi_done) (struct scsi_cmnd *);
 122
 123         /*
 124          * The following fields can be written to by the host specific code.
 125          * Everything else should be left alone.
 126          */
 127         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 128
 129         unsigned char *host_scribble;   /* The host adapter is allowed to
 130                                          * call scsi_malloc and get some memory
 131                                          * and hang it here.  The host adapter
 132                                          * is also expected to call scsi_free
 133                                          * to release this memory.  (The memory
 134                                          * obtained by scsi_malloc is guaranteed
 135                                          * to be at an address < 16Mb). */
 136
 137         int result;             /* Status code from lower level driver */
 138         int flags;              /* Command flags */
 139
 140         unsigned char tag;      /* SCSI-II queued command tag */
 141 };
 142
 143 /*
 144  * Return the driver private allocation behind the command.
 145  * Only works if cmd_size is set in the host template.
 146  */
 147 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
 148 {
 149         return cmd + 1;
 150 }
 151
 152 /* make sure not to use it with REQ_TYPE_BLOCK_PC commands */
 153 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
 154 {
 155         return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
 156 }
 157
 158 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 159 extern void scsi_put_command(struct scsi_cmnd *);
 160 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 161
 162 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 163                                  size_t *offset, size_t *len);
 164 extern void scsi_kunmap_atomic_sg(void *virt);
 165
 166 extern int scsi_init_io(struct scsi_cmnd *cmd);
 167
 168 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 169 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 170
 171 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 172 {
 173         return cmd->sdb.table.nents;
 174 }
 175
 176 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 177 {
 178         return cmd->sdb.table.sgl;
 179 }
 180
 181 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 182 {
 183         return cmd->sdb.length;
 184 }
 185
 186 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 187 {
 188         cmd->sdb.resid = resid;
 189 }
 190
 191 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 192 {
 193         return cmd->sdb.resid;
 194 }
 195
 196 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 197         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 198
 199 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
 200 {
 201         return blk_bidi_rq(cmd->request) &&
 202                 (cmd->request->next_rq->special != NULL);
 203 }
 204
 205 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
 206 {
 207         return scsi_bidi_cmnd(cmd) ?
 208                 cmd->request->next_rq->special : &cmd->sdb;
 209 }
 210
 211 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
 212 {
 213         return &cmd->sdb;
 214 }
 215
 216 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 217                                            void *buf, int buflen)
 218 {
 219         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 220                                    buf, buflen);
 221 }
 222
 223 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 224                                          void *buf, int buflen)
 225 {
 226         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 227                                  buf, buflen);
 228 }
 229
 230 /*
 231  * The operations below are hints that tell the controller driver how
 232  * to handle I/Os with DIF or similar types of protection information.
 233  */
 234 enum scsi_prot_operations {
 235         /* Normal I/O */
 236         SCSI_PROT_NORMAL = 0,
 237
 238         /* OS-HBA: Protected, HBA-Target: Unprotected */
 239         SCSI_PROT_READ_INSERT,
 240         SCSI_PROT_WRITE_STRIP,
 241
 242         /* OS-HBA: Unprotected, HBA-Target: Protected */
 243         SCSI_PROT_READ_STRIP,
 244         SCSI_PROT_WRITE_INSERT,
 245
 246         /* OS-HBA: Protected, HBA-Target: Protected */
 247         SCSI_PROT_READ_PASS,
 248         SCSI_PROT_WRITE_PASS,
 249 };
 250
 251 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 252 {
 253         scmd->prot_op = op;
 254 }
 255
 256 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 257 {
 258         return scmd->prot_op;
 259 }
 260
 261 enum scsi_prot_flags {
 262         SCSI_PROT_TRANSFER_PI           = 1 << 0,
 263         SCSI_PROT_GUARD_CHECK           = 1 << 1,
 264         SCSI_PROT_REF_CHECK             = 1 << 2,
 265         SCSI_PROT_REF_INCREMENT         = 1 << 3,
 266         SCSI_PROT_IP_CHECKSUM           = 1 << 4,
 267 };
 268
 269 /*
 270  * The controller usually does not know anything about the target it
 271  * is communicating with.  However, when DIX is enabled the controller
 272  * must be know target type so it can verify the protection
 273  * information passed along with the I/O.
 274  */
 275 enum scsi_prot_target_type {
 276         SCSI_PROT_DIF_TYPE0 = 0,
 277         SCSI_PROT_DIF_TYPE1,
 278         SCSI_PROT_DIF_TYPE2,
 279         SCSI_PROT_DIF_TYPE3,
 280 };
 281
 282 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 283 {
 284         scmd->prot_type = type;
 285 }
 286
 287 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 288 {
 289         return scmd->prot_type;
 290 }
 291
 292 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 293 {
 294         return blk_rq_pos(scmd->request);
 295 }
 296
 297 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
 298 {
 299         return scmd->device->sector_size;
 300 }
 301
 302 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
 303 {
 304         return blk_rq_pos(scmd->request) >>
 305                 (ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
 306 }
 307
 308 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 309 {
 310         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 311 }
 312
 313 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 314 {
 315         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 316 }
 317
 318 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 319 {
 320         return cmd->prot_sdb;
 321 }
 322
 323 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 324         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 325
 326 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
 327 {
 328         cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
 329 }
 330
 331 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 332 {
 333         cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 334 }
 335
 336 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 337 {
 338         cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
 339 }
 340
 341 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 342 {
 343         unsigned int xfer_len = scsi_out(scmd)->length;
 344         unsigned int prot_interval = scsi_prot_interval(scmd);
 345
 346         if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
 347                 xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
 348
 349         return xfer_len;
 350 }
 351
 352 #endif /* _SCSI_SCSI_CMND_H */