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
  11 struct Scsi_Host;
  12 struct scsi_device;
  13 struct scsi_driver;
  14
  15 /*
  16  * MAX_COMMAND_SIZE is:
  17  * The longest fixed-length SCSI CDB as per the SCSI standard.
  18  * fixed-length means: commands that their size can be determined
  19  * by their opcode and the CDB does not carry a length specifier, (unlike
  20  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
  21  * true and the SCSI standard also defines extended commands and
  22  * vendor specific commands that can be bigger than 16 bytes. The kernel
  23  * will support these using the same infrastructure used for VARLEN CDB's.
  24  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
  25  * supports without specifying a cmd_len by ULD's
  26  */
  27 #define MAX_COMMAND_SIZE 16
  28 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
  29 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
  30 #endif
  31
  32 struct scsi_data_buffer {
  33         struct sg_table table;
  34         unsigned length;
  35         int resid;
  36 };
  37
  38 /* embedded in scsi_cmnd */
  39 struct scsi_pointer {
  40         char *ptr;              /* data pointer */
  41         int this_residual;      /* left in this buffer */
  42         struct scatterlist *buffer;     /* which buffer */
  43         int buffers_residual;   /* how many buffers left */
  44
  45         dma_addr_t dma_handle;
  46
  47         volatile int Status;
  48         volatile int Message;
  49         volatile int have_data_in;
  50         volatile int sent_command;
  51         volatile int phase;
  52 };
  53
  54 struct scsi_cmnd {
  55         struct scsi_device *device;
  56         struct list_head list;  /* scsi_cmnd participates in queue lists */
  57         struct list_head eh_entry; /* entry for the host eh_cmd_q */
  58         int eh_eflags;          /* Used by error handlr */
  59
  60         /*
  61          * A SCSI Command is assigned a nonzero serial_number before passed
  62          * to the driver's queue command function.  The serial_number is
  63          * cleared when scsi_done is entered indicating that the command
  64          * has been completed.  It is a bug for LLDDs to use this number
  65          * for purposes other than printk (and even that is only useful
  66          * for debugging).
  67          */
  68         unsigned long serial_number;
  69
  70         /*
  71          * This is set to jiffies as it was when the command was first
  72          * allocated.  It is used to time how long the command has
  73          * been outstanding
  74          */
  75         unsigned long jiffies_at_alloc;
  76
  77         int retries;
  78         int allowed;
  79
  80         unsigned char prot_op;
  81         unsigned char prot_type;
  82
  83         unsigned short cmd_len;
  84         enum dma_data_direction sc_data_direction;
  85
  86         /* These elements define the operation we are about to perform */
  87         unsigned char *cmnd;
  88
  89
  90         /* These elements define the operation we ultimately want to perform */
  91         struct scsi_data_buffer sdb;
  92         struct scsi_data_buffer *prot_sdb;
  93
  94         unsigned underflow;     /* Return error if less than
  95                                    this amount is transferred */
  96
  97         unsigned transfersize;  /* How much we are guaranteed to
  98                                    transfer with each SCSI transfer
  99                                    (ie, between disconnect /
 100                                    reconnects.   Probably == sector
 101                                    size */
 102
 103         struct request *request;        /* The command we are
 104                                            working on */
 105
 106 #define SCSI_SENSE_BUFFERSIZE   96
 107         unsigned char *sense_buffer;
 108                                 /* obtained by REQUEST SENSE when
 109                                  * CHECK CONDITION is received on original
 110                                  * command (auto-sense) */
 111
 112         /* Low-level done function - can be used by low-level driver to point
 113          *        to completion function.  Not used by mid/upper level code. */
 114         void (*scsi_done) (struct scsi_cmnd *);
 115
 116         /*
 117          * The following fields can be written to by the host specific code.
 118          * Everything else should be left alone.
 119          */
 120         struct scsi_pointer SCp;        /* Scratchpad used by some host adapters */
 121
 122         unsigned char *host_scribble;   /* The host adapter is allowed to
 123                                          * call scsi_malloc and get some memory
 124                                          * and hang it here.  The host adapter
 125                                          * is also expected to call scsi_free
 126                                          * to release this memory.  (The memory
 127                                          * obtained by scsi_malloc is guaranteed
 128                                          * to be at an address < 16Mb). */
 129
 130         int result;             /* Status code from lower level driver */
 131
 132         unsigned char tag;      /* SCSI-II queued command tag */
 133 };
 134
 135 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
 136 {
 137         struct scsi_driver **sdp;
 138
 139         if (!cmd->request->rq_disk)
 140                 return NULL;
 141
 142         sdp = (struct scsi_driver **)cmd->request->rq_disk->private_data;
 143         if (!sdp)
 144                 return NULL;
 145
 146         return *sdp;
 147 }
 148
 149 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
 150 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
 151 extern void scsi_put_command(struct scsi_cmnd *);
 152 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
 153                                struct device *);
 154 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 155
 156 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 157                                  size_t *offset, size_t *len);
 158 extern void scsi_kunmap_atomic_sg(void *virt);
 159
 160 extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
 161 extern void scsi_release_buffers(struct scsi_cmnd *cmd);
 162
 163 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 164 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 165
 166 struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
 167 void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
 168
 169 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 170 {
 171         return cmd->sdb.table.nents;
 172 }
 173
 174 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
 175 {
 176         return cmd->sdb.table.sgl;
 177 }
 178
 179 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
 180 {
 181         return cmd->sdb.length;
 182 }
 183
 184 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
 185 {
 186         cmd->sdb.resid = resid;
 187 }
 188
 189 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 190 {
 191         return cmd->sdb.resid;
 192 }
 193
 194 #define scsi_for_each_sg(cmd, sg, nseg, __i)                    \
 195         for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 196
 197 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
 198 {
 199         return blk_bidi_rq(cmd->request) &&
 200                 (cmd->request->next_rq->special != NULL);
 201 }
 202
 203 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
 204 {
 205         return scsi_bidi_cmnd(cmd) ?
 206                 cmd->request->next_rq->special : &cmd->sdb;
 207 }
 208
 209 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
 210 {
 211         return &cmd->sdb;
 212 }
 213
 214 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
 215                                            void *buf, int buflen)
 216 {
 217         return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 218                                    buf, buflen);
 219 }
 220
 221 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 222                                          void *buf, int buflen)
 223 {
 224         return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
 225                                  buf, buflen);
 226 }
 227
 228 /*
 229  * The operations below are hints that tell the controller driver how
 230  * to handle I/Os with DIF or similar types of protection information.
 231  */
 232 enum scsi_prot_operations {
 233         /* Normal I/O */
 234         SCSI_PROT_NORMAL = 0,
 235
 236         /* OS-HBA: Protected, HBA-Target: Unprotected */
 237         SCSI_PROT_READ_INSERT,
 238         SCSI_PROT_WRITE_STRIP,
 239
 240         /* OS-HBA: Unprotected, HBA-Target: Protected */
 241         SCSI_PROT_READ_STRIP,
 242         SCSI_PROT_WRITE_INSERT,
 243
 244         /* OS-HBA: Protected, HBA-Target: Protected */
 245         SCSI_PROT_READ_PASS,
 246         SCSI_PROT_WRITE_PASS,
 247 };
 248
 249 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
 250 {
 251         scmd->prot_op = op;
 252 }
 253
 254 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 255 {
 256         return scmd->prot_op;
 257 }
 258
 259 /*
 260  * The controller usually does not know anything about the target it
 261  * is communicating with.  However, when DIX is enabled the controller
 262  * must be know target type so it can verify the protection
 263  * information passed along with the I/O.
 264  */
 265 enum scsi_prot_target_type {
 266         SCSI_PROT_DIF_TYPE0 = 0,
 267         SCSI_PROT_DIF_TYPE1,
 268         SCSI_PROT_DIF_TYPE2,
 269         SCSI_PROT_DIF_TYPE3,
 270 };
 271
 272 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
 273 {
 274         scmd->prot_type = type;
 275 }
 276
 277 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
 278 {
 279         return scmd->prot_type;
 280 }
 281
 282 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 283 {
 284         return blk_rq_pos(scmd->request);
 285 }
 286
 287 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 288 {
 289         return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
 290 }
 291
 292 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
 293 {
 294         return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
 295 }
 296
 297 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
 298 {
 299         return cmd->prot_sdb;
 300 }
 301
 302 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)               \
 303         for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
 304
 305 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
 306 {
 307         cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
 308 }
 309
 310 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 311 {
 312         cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
 313 }
 314
 315 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 316 {
 317         cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
 318 }
 319
 320 #endif /* _SCSI_SCSI_CMND_H */