xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision 5f32c314)
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 	struct delayed_work abort_work;
59 	int eh_eflags;		/* Used by error handlr */
60 
61 	/*
62 	 * A SCSI Command is assigned a nonzero serial_number before passed
63 	 * to the driver's queue command function.  The serial_number is
64 	 * cleared when scsi_done is entered indicating that the command
65 	 * has been completed.  It is a bug for LLDDs to use this number
66 	 * for purposes other than printk (and even that is only useful
67 	 * for debugging).
68 	 */
69 	unsigned long serial_number;
70 
71 	/*
72 	 * This is set to jiffies as it was when the command was first
73 	 * allocated.  It is used to time how long the command has
74 	 * been outstanding
75 	 */
76 	unsigned long jiffies_at_alloc;
77 
78 	int retries;
79 	int allowed;
80 
81 	unsigned char prot_op;
82 	unsigned char prot_type;
83 
84 	unsigned short cmd_len;
85 	enum dma_data_direction sc_data_direction;
86 
87 	/* These elements define the operation we are about to perform */
88 	unsigned char *cmnd;
89 
90 
91 	/* These elements define the operation we ultimately want to perform */
92 	struct scsi_data_buffer sdb;
93 	struct scsi_data_buffer *prot_sdb;
94 
95 	unsigned underflow;	/* Return error if less than
96 				   this amount is transferred */
97 
98 	unsigned transfersize;	/* How much we are guaranteed to
99 				   transfer with each SCSI transfer
100 				   (ie, between disconnect /
101 				   reconnects.   Probably == sector
102 				   size */
103 
104 	struct request *request;	/* The command we are
105 				   	   working on */
106 
107 #define SCSI_SENSE_BUFFERSIZE 	96
108 	unsigned char *sense_buffer;
109 				/* obtained by REQUEST SENSE when
110 				 * CHECK CONDITION is received on original
111 				 * command (auto-sense) */
112 
113 	/* Low-level done function - can be used by low-level driver to point
114 	 *        to completion function.  Not used by mid/upper level code. */
115 	void (*scsi_done) (struct scsi_cmnd *);
116 
117 	/*
118 	 * The following fields can be written to by the host specific code.
119 	 * Everything else should be left alone.
120 	 */
121 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
122 
123 	unsigned char *host_scribble;	/* The host adapter is allowed to
124 					 * call scsi_malloc and get some memory
125 					 * and hang it here.  The host adapter
126 					 * is also expected to call scsi_free
127 					 * to release this memory.  (The memory
128 					 * obtained by scsi_malloc is guaranteed
129 					 * to be at an address < 16Mb). */
130 
131 	int result;		/* Status code from lower level driver */
132 
133 	unsigned char tag;	/* SCSI-II queued command tag */
134 };
135 
136 /* make sure not to use it with REQ_TYPE_BLOCK_PC commands */
137 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
138 {
139 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
140 }
141 
142 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
143 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
144 extern void scsi_put_command(struct scsi_cmnd *);
145 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
146 			       struct device *);
147 extern void scsi_finish_command(struct scsi_cmnd *cmd);
148 
149 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
150 				 size_t *offset, size_t *len);
151 extern void scsi_kunmap_atomic_sg(void *virt);
152 
153 extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
154 extern void scsi_release_buffers(struct scsi_cmnd *cmd);
155 
156 extern int scsi_dma_map(struct scsi_cmnd *cmd);
157 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
158 
159 struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
160 void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
161 
162 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
163 {
164 	return cmd->sdb.table.nents;
165 }
166 
167 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
168 {
169 	return cmd->sdb.table.sgl;
170 }
171 
172 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
173 {
174 	return cmd->sdb.length;
175 }
176 
177 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
178 {
179 	cmd->sdb.resid = resid;
180 }
181 
182 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
183 {
184 	return cmd->sdb.resid;
185 }
186 
187 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
188 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
189 
190 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
191 {
192 	return blk_bidi_rq(cmd->request) &&
193 		(cmd->request->next_rq->special != NULL);
194 }
195 
196 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
197 {
198 	return scsi_bidi_cmnd(cmd) ?
199 		cmd->request->next_rq->special : &cmd->sdb;
200 }
201 
202 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
203 {
204 	return &cmd->sdb;
205 }
206 
207 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
208 					   void *buf, int buflen)
209 {
210 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
211 				   buf, buflen);
212 }
213 
214 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
215 					 void *buf, int buflen)
216 {
217 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
218 				 buf, buflen);
219 }
220 
221 /*
222  * The operations below are hints that tell the controller driver how
223  * to handle I/Os with DIF or similar types of protection information.
224  */
225 enum scsi_prot_operations {
226 	/* Normal I/O */
227 	SCSI_PROT_NORMAL = 0,
228 
229 	/* OS-HBA: Protected, HBA-Target: Unprotected */
230 	SCSI_PROT_READ_INSERT,
231 	SCSI_PROT_WRITE_STRIP,
232 
233 	/* OS-HBA: Unprotected, HBA-Target: Protected */
234 	SCSI_PROT_READ_STRIP,
235 	SCSI_PROT_WRITE_INSERT,
236 
237 	/* OS-HBA: Protected, HBA-Target: Protected */
238 	SCSI_PROT_READ_PASS,
239 	SCSI_PROT_WRITE_PASS,
240 };
241 
242 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
243 {
244 	scmd->prot_op = op;
245 }
246 
247 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
248 {
249 	return scmd->prot_op;
250 }
251 
252 /*
253  * The controller usually does not know anything about the target it
254  * is communicating with.  However, when DIX is enabled the controller
255  * must be know target type so it can verify the protection
256  * information passed along with the I/O.
257  */
258 enum scsi_prot_target_type {
259 	SCSI_PROT_DIF_TYPE0 = 0,
260 	SCSI_PROT_DIF_TYPE1,
261 	SCSI_PROT_DIF_TYPE2,
262 	SCSI_PROT_DIF_TYPE3,
263 };
264 
265 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
266 {
267 	scmd->prot_type = type;
268 }
269 
270 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
271 {
272 	return scmd->prot_type;
273 }
274 
275 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
276 {
277 	return blk_rq_pos(scmd->request);
278 }
279 
280 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
281 {
282 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
283 }
284 
285 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
286 {
287 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
288 }
289 
290 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
291 {
292 	return cmd->prot_sdb;
293 }
294 
295 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
296 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
297 
298 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
299 {
300 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
301 }
302 
303 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
304 {
305 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
306 }
307 
308 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
309 {
310 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
311 }
312 
313 #endif /* _SCSI_SCSI_CMND_H */
314