xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision 4d2804b7)
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 #include <scsi/scsi_request.h>
12 
13 struct Scsi_Host;
14 struct scsi_driver;
15 
16 #include <scsi/scsi_device.h>
17 
18 /*
19  * MAX_COMMAND_SIZE is:
20  * The longest fixed-length SCSI CDB as per the SCSI standard.
21  * fixed-length means: commands that their size can be determined
22  * by their opcode and the CDB does not carry a length specifier, (unlike
23  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
24  * true and the SCSI standard also defines extended commands and
25  * vendor specific commands that can be bigger than 16 bytes. The kernel
26  * will support these using the same infrastructure used for VARLEN CDB's.
27  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
28  * supports without specifying a cmd_len by ULD's
29  */
30 #define MAX_COMMAND_SIZE 16
31 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
32 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
33 #endif
34 
35 struct scsi_data_buffer {
36 	struct sg_table table;
37 	unsigned length;
38 	int resid;
39 };
40 
41 /* embedded in scsi_cmnd */
42 struct scsi_pointer {
43 	char *ptr;		/* data pointer */
44 	int this_residual;	/* left in this buffer */
45 	struct scatterlist *buffer;	/* which buffer */
46 	int buffers_residual;	/* how many buffers left */
47 
48         dma_addr_t dma_handle;
49 
50 	volatile int Status;
51 	volatile int Message;
52 	volatile int have_data_in;
53 	volatile int sent_command;
54 	volatile int phase;
55 };
56 
57 /* for scmd->flags */
58 #define SCMD_TAGGED		(1 << 0)
59 
60 struct scsi_cmnd {
61 	struct scsi_request req;
62 	struct scsi_device *device;
63 	struct list_head list;  /* scsi_cmnd participates in queue lists */
64 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
65 	struct delayed_work abort_work;
66 	int eh_eflags;		/* Used by error handlr */
67 
68 	/*
69 	 * A SCSI Command is assigned a nonzero serial_number before passed
70 	 * to the driver's queue command function.  The serial_number is
71 	 * cleared when scsi_done is entered indicating that the command
72 	 * has been completed.  It is a bug for LLDDs to use this number
73 	 * for purposes other than printk (and even that is only useful
74 	 * for debugging).
75 	 */
76 	unsigned long serial_number;
77 
78 	/*
79 	 * This is set to jiffies as it was when the command was first
80 	 * allocated.  It is used to time how long the command has
81 	 * been outstanding
82 	 */
83 	unsigned long jiffies_at_alloc;
84 
85 	int retries;
86 	int allowed;
87 
88 	unsigned char prot_op;
89 	unsigned char prot_type;
90 	unsigned char prot_flags;
91 
92 	unsigned short cmd_len;
93 	enum dma_data_direction sc_data_direction;
94 
95 	/* These elements define the operation we are about to perform */
96 	unsigned char *cmnd;
97 
98 
99 	/* These elements define the operation we ultimately want to perform */
100 	struct scsi_data_buffer sdb;
101 	struct scsi_data_buffer *prot_sdb;
102 
103 	unsigned underflow;	/* Return error if less than
104 				   this amount is transferred */
105 
106 	unsigned transfersize;	/* How much we are guaranteed to
107 				   transfer with each SCSI transfer
108 				   (ie, between disconnect /
109 				   reconnects.   Probably == sector
110 				   size */
111 
112 	struct request *request;	/* The command we are
113 				   	   working on */
114 
115 #define SCSI_SENSE_BUFFERSIZE 	96
116 	unsigned char *sense_buffer;
117 				/* obtained by REQUEST SENSE when
118 				 * CHECK CONDITION is received on original
119 				 * command (auto-sense) */
120 
121 	/* Low-level done function - can be used by low-level driver to point
122 	 *        to completion function.  Not used by mid/upper level code. */
123 	void (*scsi_done) (struct scsi_cmnd *);
124 
125 	/*
126 	 * The following fields can be written to by the host specific code.
127 	 * Everything else should be left alone.
128 	 */
129 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
130 
131 	unsigned char *host_scribble;	/* The host adapter is allowed to
132 					 * call scsi_malloc and get some memory
133 					 * and hang it here.  The host adapter
134 					 * is also expected to call scsi_free
135 					 * to release this memory.  (The memory
136 					 * obtained by scsi_malloc is guaranteed
137 					 * to be at an address < 16Mb). */
138 
139 	int result;		/* Status code from lower level driver */
140 	int flags;		/* Command flags */
141 
142 	unsigned char tag;	/* SCSI-II queued command tag */
143 };
144 
145 /*
146  * Return the driver private allocation behind the command.
147  * Only works if cmd_size is set in the host template.
148  */
149 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
150 {
151 	return cmd + 1;
152 }
153 
154 /* make sure not to use it with passthrough commands */
155 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
156 {
157 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
158 }
159 
160 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
161 extern void scsi_put_command(struct scsi_cmnd *);
162 extern void scsi_finish_command(struct scsi_cmnd *cmd);
163 
164 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
165 				 size_t *offset, size_t *len);
166 extern void scsi_kunmap_atomic_sg(void *virt);
167 
168 extern int scsi_init_io(struct scsi_cmnd *cmd);
169 
170 extern int scsi_dma_map(struct scsi_cmnd *cmd);
171 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
172 
173 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
174 {
175 	return cmd->sdb.table.nents;
176 }
177 
178 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
179 {
180 	return cmd->sdb.table.sgl;
181 }
182 
183 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
184 {
185 	return cmd->sdb.length;
186 }
187 
188 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
189 {
190 	cmd->sdb.resid = resid;
191 }
192 
193 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
194 {
195 	return cmd->sdb.resid;
196 }
197 
198 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
199 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
200 
201 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
202 {
203 	return blk_bidi_rq(cmd->request) &&
204 		(cmd->request->next_rq->special != NULL);
205 }
206 
207 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
208 {
209 	return scsi_bidi_cmnd(cmd) ?
210 		cmd->request->next_rq->special : &cmd->sdb;
211 }
212 
213 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
214 {
215 	return &cmd->sdb;
216 }
217 
218 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
219 					   void *buf, int buflen)
220 {
221 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
222 				   buf, buflen);
223 }
224 
225 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
226 					 void *buf, int buflen)
227 {
228 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
229 				 buf, buflen);
230 }
231 
232 /*
233  * The operations below are hints that tell the controller driver how
234  * to handle I/Os with DIF or similar types of protection information.
235  */
236 enum scsi_prot_operations {
237 	/* Normal I/O */
238 	SCSI_PROT_NORMAL = 0,
239 
240 	/* OS-HBA: Protected, HBA-Target: Unprotected */
241 	SCSI_PROT_READ_INSERT,
242 	SCSI_PROT_WRITE_STRIP,
243 
244 	/* OS-HBA: Unprotected, HBA-Target: Protected */
245 	SCSI_PROT_READ_STRIP,
246 	SCSI_PROT_WRITE_INSERT,
247 
248 	/* OS-HBA: Protected, HBA-Target: Protected */
249 	SCSI_PROT_READ_PASS,
250 	SCSI_PROT_WRITE_PASS,
251 };
252 
253 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
254 {
255 	scmd->prot_op = op;
256 }
257 
258 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
259 {
260 	return scmd->prot_op;
261 }
262 
263 enum scsi_prot_flags {
264 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
265 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
266 	SCSI_PROT_REF_CHECK		= 1 << 2,
267 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
268 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
269 };
270 
271 /*
272  * The controller usually does not know anything about the target it
273  * is communicating with.  However, when DIX is enabled the controller
274  * must be know target type so it can verify the protection
275  * information passed along with the I/O.
276  */
277 enum scsi_prot_target_type {
278 	SCSI_PROT_DIF_TYPE0 = 0,
279 	SCSI_PROT_DIF_TYPE1,
280 	SCSI_PROT_DIF_TYPE2,
281 	SCSI_PROT_DIF_TYPE3,
282 };
283 
284 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
285 {
286 	scmd->prot_type = type;
287 }
288 
289 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
290 {
291 	return scmd->prot_type;
292 }
293 
294 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
295 {
296 	return blk_rq_pos(scmd->request);
297 }
298 
299 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
300 {
301 	return scmd->device->sector_size;
302 }
303 
304 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
305 {
306 	return blk_rq_pos(scmd->request) >>
307 		(ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
308 }
309 
310 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
311 {
312 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
313 }
314 
315 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
316 {
317 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
318 }
319 
320 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
321 {
322 	return cmd->prot_sdb;
323 }
324 
325 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
326 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
327 
328 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
329 {
330 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
331 }
332 
333 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
334 {
335 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
336 }
337 
338 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
339 {
340 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
341 }
342 
343 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
344 {
345 	unsigned int xfer_len = scsi_out(scmd)->length;
346 	unsigned int prot_interval = scsi_prot_interval(scmd);
347 
348 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
349 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
350 
351 	return xfer_len;
352 }
353 
354 #endif /* _SCSI_SCSI_CMND_H */
355