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_device;
  14 struct scsi_driver;
  15
  16 /*
  17  * MAX_COMMAND_SIZE is:
  18  * The longest fixed-length SCSI CDB as per the SCSI standard.
  19  * fixed-length means: commands that their size can be determined
  20  * by their opcode and the CDB does not carry a length specifier, (unlike
  21  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
  22  * true and the SCSI standard also defines extended commands and
  23  * vendor specific commands that can be bigger than 16 bytes. The kernel
  24  * will support these using the same infrastructure used for VARLEN CDB's.
  25  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
  26  * supports without specifying a cmd_len by ULD's
  27  */
  28 #define MAX_COMMAND_SIZE 16
  29 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
  30 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
  31 #endif
  32
  33 struct scsi_data_buffer {
  34         struct sg_table table;
  35         unsigned length;
  36         int resid;
  37 };
  38
  39 /* embedded in scsi_cmnd */
  40 struct scsi_pointer {
  41         char *ptr;              /* data pointer */
  42         int this_residual;      /* left in this buffer */
  43         struct scatterlist *buffer;     /* which buffer */
  44         int buffers_residual;   /* how many buffers left */
  45
  46         dma_addr_t dma_handle;
  47
  48         volatile int Status;
  49         volatile int Message;
  50         volatile int have_data_in;
  51         volatile int sent_command;
  52         volatile int phase;
  53 };
  54
  55 struct scsi_cmnd {
  56         struct scsi_device *device;
  57         struct list_head list;  /* scsi_cmnd participates in queue lists */
  58         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  59         struct delayed_work abort_work;
  60         int eh_eflags;          /* Used by error handlr */
  61
  62         /*
  63          * A SCSI Command is assigned a nonzero serial_number before passed
  64          * to the driver's queue command function.  The serial_number is
  65          * cleared when scsi_done is entered indicating that the command
  66          * has been completed.  It is a bug for LLDDs to use this number
  67          * for purposes other than printk (and even that is only useful
  68          * for debugging).
  69          */
  70         unsigned long serial_number;
  71
  72         /*
  73          * This is set to jiffies as it was when the command was first
  74          * allocated.  It is used to time how long the command has
  75          * been outstanding
  76          */
  77         unsigned long jiffies_at_alloc;
  78
  79         int retries;
  80         int allowed;
  81
  82         unsigned char prot_op;
  83         unsigned char prot_type;
  84
  85         unsigned short cmd_len;
  86         enum dma_data_direction sc_data_direction;
  87
  88         /* These elements define the operation we are about to perform */
  89         unsigned char *cmnd;
  90
  91
  92         /* These elements define the operation we ultimately want to perform */
  93         struct scsi_data_buffer sdb;
  94         struct scsi_data_buffer *prot_sdb;
  95
  96         unsigned underflow;     /* Return error if less than
  97                                    this amount is transferred */
  98
  99         unsigned transfersize;  /* How much we are guaranteed to
 100                                    transfer with each SCSI transfer
 101                                    (ie, between disconnect /
 102                                    reconnects.   Probably == sector
 103                                    size */
 104
 105         struct request *request;        /* The command we are
 106                                            working on */
 107
 108 #define SCSI_SENSE_BUFFERSIZE   96
 109         unsigned char *sense_buffer;
 110                                 /* obtained by REQUEST SENSE when
 111                                  * CHECK CONDITION is received on original
 112                                  * command (auto-sense) */
 113
 114         /* Low-level done function - can be used by low-level driver to point
 115          *        to completion function.  Not used by mid/upper level code. */
 116         void (*scsi_done) (struct scsi_cmnd *);
 117
 118         /*
 119          * The following fields can be written to by the host specific code.
 120          * Everything else should be left alone.
 121          */
 122         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 123
 124         unsigned char *host_scribble;   /* The host adapter is allowed to
 125                                          * call scsi_malloc and get some memory
 126                                          * and hang it here.  The host adapter
 127                                          * is also expected to call scsi_free
 128                                          * to release this memory.  (The memory
 129                                          * obtained by scsi_malloc is guaranteed
 130                                          * to be at an address < 16Mb). */
 131
 132         int result;             /* Status code from lower level driver */
 133
 134         unsigned char tag;      /* SCSI-II queued command tag */
 135 };
 136
 137 /*
 138  * Return the driver private allocation behind the command.
 139  * Only works if cmd_size is set in the host template.
 140  */
 141 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
 142 {
 143         return cmd + 1;
 144 }
 145
 146 /* make sure not to use it with REQ_TYPE_BLOCK_PC commands */
 147 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
 148 {
 149         return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
 150 }
 151
 152 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 153 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
 154 extern void scsi_put_command(struct scsi_cmnd *);
 155 extern void __scsi_put_command(struct Scsi_Host *, 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 extern void scsi_release_buffers(struct scsi_cmnd *cmd);
 164
 165 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 166 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 167
 168 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 169 {
 170         return cmd->sdb.table.nents;
 171 }
 172
 173 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 174 {
 175         return cmd->sdb.table.sgl;
 176 }
 177
 178 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 179 {
 180         return cmd->sdb.length;
 181 }
 182
 183 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 184 {
 185         cmd->sdb.resid = resid;
 186 }
 187
 188 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 189 {
 190         return cmd->sdb.resid;
 191 }
 192
 193 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 194         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 195
 196 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
 197 {
 198         return blk_bidi_rq(cmd->request) &&
 199                 (cmd->request->next_rq->special != NULL);
 200 }
 201
 202 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
 203 {
 204         return scsi_bidi_cmnd(cmd) ?
 205                 cmd->request->next_rq->special : &cmd->sdb;
 206 }
 207
 208 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
 209 {
 210         return &cmd->sdb;
 211 }
 212
 213 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 214                                            void *buf, int buflen)
 215 {
 216         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 217                                    buf, buflen);
 218 }
 219
 220 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 221                                          void *buf, int buflen)
 222 {
 223         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 224                                  buf, buflen);
 225 }
 226
 227 /*
 228  * The operations below are hints that tell the controller driver how
 229  * to handle I/Os with DIF or similar types of protection information.
 230  */
 231 enum scsi_prot_operations {
 232         /* Normal I/O */
 233         SCSI_PROT_NORMAL = 0,
 234
 235         /* OS-HBA: Protected, HBA-Target: Unprotected */
 236         SCSI_PROT_READ_INSERT,
 237         SCSI_PROT_WRITE_STRIP,
 238
 239         /* OS-HBA: Unprotected, HBA-Target: Protected */
 240         SCSI_PROT_READ_STRIP,
 241         SCSI_PROT_WRITE_INSERT,
 242
 243         /* OS-HBA: Protected, HBA-Target: Protected */
 244         SCSI_PROT_READ_PASS,
 245         SCSI_PROT_WRITE_PASS,
 246 };
 247
 248 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 249 {
 250         scmd->prot_op = op;
 251 }
 252
 253 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 254 {
 255         return scmd->prot_op;
 256 }
 257
 258 /*
 259  * The controller usually does not know anything about the target it
 260  * is communicating with.  However, when DIX is enabled the controller
 261  * must be know target type so it can verify the protection
 262  * information passed along with the I/O.
 263  */
 264 enum scsi_prot_target_type {
 265         SCSI_PROT_DIF_TYPE0 = 0,
 266         SCSI_PROT_DIF_TYPE1,
 267         SCSI_PROT_DIF_TYPE2,
 268         SCSI_PROT_DIF_TYPE3,
 269 };
 270
 271 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 272 {
 273         scmd->prot_type = type;
 274 }
 275
 276 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 277 {
 278         return scmd->prot_type;
 279 }
 280
 281 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 282 {
 283         return blk_rq_pos(scmd->request);
 284 }
 285
 286 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 287 {
 288         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 289 }
 290
 291 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 292 {
 293         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 294 }
 295
 296 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 297 {
 298         return cmd->prot_sdb;
 299 }
 300
 301 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 302         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 303
 304 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
 305 {
 306         cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
 307 }
 308
 309 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 310 {
 311         cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 312 }
 313
 314 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 315 {
 316         cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
 317 }
 318
 319 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 320 {
 321         unsigned int xfer_len = scsi_out(scmd)->length;
 322         unsigned int prot_op = scsi_get_prot_op(scmd);
 323         unsigned int sector_size = scmd->device->sector_size;
 324
 325         switch (prot_op) {
 326         case SCSI_PROT_NORMAL:
 327         case SCSI_PROT_WRITE_STRIP:
 328         case SCSI_PROT_READ_INSERT:
 329                 return xfer_len;
 330         }
 331
 332         return xfer_len + (xfer_len >> ilog2(sector_size)) * 8;
 333 }
 334
 335 #endif /* _SCSI_SCSI_CMND_H */