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scsi_cmnd.h
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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 
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 
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 {
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;
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 */
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 /* make sure not to use it with REQ_TYPE_BLOCK_PC commands */
136 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
137 {
138  return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
139 }
140 
141 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
142 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
143 extern void scsi_put_command(struct scsi_cmnd *);
144 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
145  struct device *);
146 extern void scsi_finish_command(struct scsi_cmnd *cmd);
147 
148 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
149  size_t *offset, size_t *len);
150 extern void scsi_kunmap_atomic_sg(void *virt);
151 
152 extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
153 extern void scsi_release_buffers(struct scsi_cmnd *cmd);
154 
155 extern int scsi_dma_map(struct scsi_cmnd *cmd);
156 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
157 
160 
161 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
162 {
163  return cmd->sdb.table.nents;
164 }
165 
166 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
167 {
168  return cmd->sdb.table.sgl;
169 }
170 
171 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
172 {
173  return cmd->sdb.length;
174 }
175 
176 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
177 {
178  cmd->sdb.resid = resid;
179 }
180 
181 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
182 {
183  return cmd->sdb.resid;
184 }
185 
186 #define scsi_for_each_sg(cmd, sg, nseg, __i) \
187  for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
188 
189 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
190 {
191  return blk_bidi_rq(cmd->request) &&
192  (cmd->request->next_rq->special != NULL);
193 }
194 
195 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
196 {
197  return scsi_bidi_cmnd(cmd) ?
198  cmd->request->next_rq->special : &cmd->sdb;
199 }
200 
201 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
202 {
203  return &cmd->sdb;
204 }
205 
206 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
207  void *buf, int buflen)
208 {
209  return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
210  buf, buflen);
211 }
212 
213 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
214  void *buf, int buflen)
215 {
216  return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
217  buf, buflen);
218 }
219 
220 /*
221  * The operations below are hints that tell the controller driver how
222  * to handle I/Os with DIF or similar types of protection information.
223  */
225  /* Normal I/O */
227 
228  /* OS-HBA: Protected, HBA-Target: Unprotected */
231 
232  /* OS-HBA: Unprotected, HBA-Target: Protected */
235 
236  /* OS-HBA: Protected, HBA-Target: Protected */
239 };
240 
241 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
242 {
243  scmd->prot_op = op;
244 }
245 
246 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
247 {
248  return scmd->prot_op;
249 }
250 
251 /*
252  * The controller usually does not know anything about the target it
253  * is communicating with. However, when DIX is enabled the controller
254  * must be know target type so it can verify the protection
255  * information passed along with the I/O.
256  */
262 };
263 
264 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
265 {
266  scmd->prot_type = type;
267 }
268 
269 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
270 {
271  return scmd->prot_type;
272 }
273 
274 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
275 {
276  return blk_rq_pos(scmd->request);
277 }
278 
279 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
280 {
281  return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
282 }
283 
284 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
285 {
286  return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
287 }
288 
289 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
290 {
291  return cmd->prot_sdb;
292 }
293 
294 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i) \
295  for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
296 
297 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
298 {
299  cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
300 }
301 
302 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
303 {
304  cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
305 }
306 
307 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
308 {
309  cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
310 }
311 
312 #endif /* _SCSI_SCSI_CMND_H */