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