xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision ca460cc2)
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_driver;
14 
15 #include <scsi/scsi_device.h>
16 
17 /*
18  * MAX_COMMAND_SIZE is:
19  * The longest fixed-length SCSI CDB as per the SCSI standard.
20  * fixed-length means: commands that their size can be determined
21  * by their opcode and the CDB does not carry a length specifier, (unlike
22  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
23  * true and the SCSI standard also defines extended commands and
24  * vendor specific commands that can be bigger than 16 bytes. The kernel
25  * will support these using the same infrastructure used for VARLEN CDB's.
26  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
27  * supports without specifying a cmd_len by ULD's
28  */
29 #define MAX_COMMAND_SIZE 16
30 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
31 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
32 #endif
33 
34 struct scsi_data_buffer {
35 	struct sg_table table;
36 	unsigned length;
37 	int resid;
38 };
39 
40 /* embedded in scsi_cmnd */
41 struct scsi_pointer {
42 	char *ptr;		/* data pointer */
43 	int this_residual;	/* left in this buffer */
44 	struct scatterlist *buffer;	/* which buffer */
45 	int buffers_residual;	/* how many buffers left */
46 
47         dma_addr_t dma_handle;
48 
49 	volatile int Status;
50 	volatile int Message;
51 	volatile int have_data_in;
52 	volatile int sent_command;
53 	volatile int phase;
54 };
55 
56 struct scsi_cmnd {
57 	struct scsi_device *device;
58 	struct list_head list;  /* scsi_cmnd participates in queue lists */
59 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
60 	struct delayed_work abort_work;
61 	int eh_eflags;		/* Used by error handlr */
62 
63 	/*
64 	 * A SCSI Command is assigned a nonzero serial_number before passed
65 	 * to the driver's queue command function.  The serial_number is
66 	 * cleared when scsi_done is entered indicating that the command
67 	 * has been completed.  It is a bug for LLDDs to use this number
68 	 * for purposes other than printk (and even that is only useful
69 	 * for debugging).
70 	 */
71 	unsigned long serial_number;
72 
73 	/*
74 	 * This is set to jiffies as it was when the command was first
75 	 * allocated.  It is used to time how long the command has
76 	 * been outstanding
77 	 */
78 	unsigned long jiffies_at_alloc;
79 
80 	int retries;
81 	int allowed;
82 
83 	unsigned char prot_op;
84 	unsigned char prot_type;
85 	unsigned char prot_flags;
86 
87 	unsigned short cmd_len;
88 	enum dma_data_direction sc_data_direction;
89 
90 	/* These elements define the operation we are about to perform */
91 	unsigned char *cmnd;
92 
93 
94 	/* These elements define the operation we ultimately want to perform */
95 	struct scsi_data_buffer sdb;
96 	struct scsi_data_buffer *prot_sdb;
97 
98 	unsigned underflow;	/* Return error if less than
99 				   this amount is transferred */
100 
101 	unsigned transfersize;	/* How much we are guaranteed to
102 				   transfer with each SCSI transfer
103 				   (ie, between disconnect /
104 				   reconnects.   Probably == sector
105 				   size */
106 
107 	struct request *request;	/* The command we are
108 				   	   working on */
109 
110 #define SCSI_SENSE_BUFFERSIZE 	96
111 	unsigned char *sense_buffer;
112 				/* obtained by REQUEST SENSE when
113 				 * CHECK CONDITION is received on original
114 				 * command (auto-sense) */
115 
116 	/* Low-level done function - can be used by low-level driver to point
117 	 *        to completion function.  Not used by mid/upper level code. */
118 	void (*scsi_done) (struct scsi_cmnd *);
119 
120 	/*
121 	 * The following fields can be written to by the host specific code.
122 	 * Everything else should be left alone.
123 	 */
124 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
125 
126 	unsigned char *host_scribble;	/* The host adapter is allowed to
127 					 * call scsi_malloc and get some memory
128 					 * and hang it here.  The host adapter
129 					 * is also expected to call scsi_free
130 					 * to release this memory.  (The memory
131 					 * obtained by scsi_malloc is guaranteed
132 					 * to be at an address < 16Mb). */
133 
134 	int result;		/* Status code from lower level driver */
135 
136 	unsigned char tag;	/* SCSI-II queued command tag */
137 };
138 
139 /*
140  * Return the driver private allocation behind the command.
141  * Only works if cmd_size is set in the host template.
142  */
143 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
144 {
145 	return cmd + 1;
146 }
147 
148 /* make sure not to use it with REQ_TYPE_BLOCK_PC commands */
149 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
150 {
151 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
152 }
153 
154 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
155 extern void scsi_put_command(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 
164 extern int scsi_dma_map(struct scsi_cmnd *cmd);
165 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
166 
167 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
168 {
169 	return cmd->sdb.table.nents;
170 }
171 
172 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
173 {
174 	return cmd->sdb.table.sgl;
175 }
176 
177 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
178 {
179 	return cmd->sdb.length;
180 }
181 
182 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
183 {
184 	cmd->sdb.resid = resid;
185 }
186 
187 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
188 {
189 	return cmd->sdb.resid;
190 }
191 
192 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
193 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
194 
195 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
196 {
197 	return blk_bidi_rq(cmd->request) &&
198 		(cmd->request->next_rq->special != NULL);
199 }
200 
201 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
202 {
203 	return scsi_bidi_cmnd(cmd) ?
204 		cmd->request->next_rq->special : &cmd->sdb;
205 }
206 
207 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
208 {
209 	return &cmd->sdb;
210 }
211 
212 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
213 					   void *buf, int buflen)
214 {
215 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
216 				   buf, buflen);
217 }
218 
219 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
220 					 void *buf, int buflen)
221 {
222 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
223 				 buf, buflen);
224 }
225 
226 /*
227  * The operations below are hints that tell the controller driver how
228  * to handle I/Os with DIF or similar types of protection information.
229  */
230 enum scsi_prot_operations {
231 	/* Normal I/O */
232 	SCSI_PROT_NORMAL = 0,
233 
234 	/* OS-HBA: Protected, HBA-Target: Unprotected */
235 	SCSI_PROT_READ_INSERT,
236 	SCSI_PROT_WRITE_STRIP,
237 
238 	/* OS-HBA: Unprotected, HBA-Target: Protected */
239 	SCSI_PROT_READ_STRIP,
240 	SCSI_PROT_WRITE_INSERT,
241 
242 	/* OS-HBA: Protected, HBA-Target: Protected */
243 	SCSI_PROT_READ_PASS,
244 	SCSI_PROT_WRITE_PASS,
245 };
246 
247 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
248 {
249 	scmd->prot_op = op;
250 }
251 
252 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
253 {
254 	return scmd->prot_op;
255 }
256 
257 enum scsi_prot_flags {
258 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
259 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
260 	SCSI_PROT_REF_CHECK		= 1 << 2,
261 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
262 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
263 };
264 
265 /*
266  * The controller usually does not know anything about the target it
267  * is communicating with.  However, when DIX is enabled the controller
268  * must be know target type so it can verify the protection
269  * information passed along with the I/O.
270  */
271 enum scsi_prot_target_type {
272 	SCSI_PROT_DIF_TYPE0 = 0,
273 	SCSI_PROT_DIF_TYPE1,
274 	SCSI_PROT_DIF_TYPE2,
275 	SCSI_PROT_DIF_TYPE3,
276 };
277 
278 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
279 {
280 	scmd->prot_type = type;
281 }
282 
283 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
284 {
285 	return scmd->prot_type;
286 }
287 
288 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
289 {
290 	return blk_rq_pos(scmd->request);
291 }
292 
293 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
294 {
295 	return scmd->device->sector_size;
296 }
297 
298 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
299 {
300 	return blk_rq_pos(scmd->request) >>
301 		(ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
302 }
303 
304 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
305 {
306 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
307 }
308 
309 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
310 {
311 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
312 }
313 
314 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
315 {
316 	return cmd->prot_sdb;
317 }
318 
319 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
320 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
321 
322 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
323 {
324 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
325 }
326 
327 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
328 {
329 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
330 }
331 
332 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
333 {
334 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
335 }
336 
337 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
338 {
339 	unsigned int xfer_len = scsi_out(scmd)->length;
340 	unsigned int prot_interval = scsi_prot_interval(scmd);
341 
342 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
343 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
344 
345 	return xfer_len;
346 }
347 
348 #endif /* _SCSI_SCSI_CMND_H */
349