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