xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision dea54fba)
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 #define SCMD_UNCHECKED_ISA_DMA	(1 << 1)
60 #define SCMD_ZONE_WRITE_LOCK	(1 << 2)
61 
62 struct scsi_cmnd {
63 	struct scsi_request req;
64 	struct scsi_device *device;
65 	struct list_head list;  /* scsi_cmnd participates in queue lists */
66 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
67 	struct delayed_work abort_work;
68 	int eh_eflags;		/* Used by error handlr */
69 
70 	/*
71 	 * A SCSI Command is assigned a nonzero serial_number before passed
72 	 * to the driver's queue command function.  The serial_number is
73 	 * cleared when scsi_done is entered indicating that the command
74 	 * has been completed.  It is a bug for LLDDs to use this number
75 	 * for purposes other than printk (and even that is only useful
76 	 * for debugging).
77 	 */
78 	unsigned long serial_number;
79 
80 	/*
81 	 * This is set to jiffies as it was when the command was first
82 	 * allocated.  It is used to time how long the command has
83 	 * been outstanding
84 	 */
85 	unsigned long jiffies_at_alloc;
86 
87 	int retries;
88 	int allowed;
89 
90 	unsigned char prot_op;
91 	unsigned char prot_type;
92 	unsigned char prot_flags;
93 
94 	unsigned short cmd_len;
95 	enum dma_data_direction sc_data_direction;
96 
97 	/* These elements define the operation we are about to perform */
98 	unsigned char *cmnd;
99 
100 
101 	/* These elements define the operation we ultimately want to perform */
102 	struct scsi_data_buffer sdb;
103 	struct scsi_data_buffer *prot_sdb;
104 
105 	unsigned underflow;	/* Return error if less than
106 				   this amount is transferred */
107 
108 	unsigned transfersize;	/* How much we are guaranteed to
109 				   transfer with each SCSI transfer
110 				   (ie, between disconnect /
111 				   reconnects.   Probably == sector
112 				   size */
113 
114 	struct request *request;	/* The command we are
115 				   	   working on */
116 
117 #define SCSI_SENSE_BUFFERSIZE 	96
118 	unsigned char *sense_buffer;
119 				/* obtained by REQUEST SENSE when
120 				 * CHECK CONDITION is received on original
121 				 * command (auto-sense) */
122 
123 	/* Low-level done function - can be used by low-level driver to point
124 	 *        to completion function.  Not used by mid/upper level code. */
125 	void (*scsi_done) (struct scsi_cmnd *);
126 
127 	/*
128 	 * The following fields can be written to by the host specific code.
129 	 * Everything else should be left alone.
130 	 */
131 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
132 
133 	unsigned char *host_scribble;	/* The host adapter is allowed to
134 					 * call scsi_malloc and get some memory
135 					 * and hang it here.  The host adapter
136 					 * is also expected to call scsi_free
137 					 * to release this memory.  (The memory
138 					 * obtained by scsi_malloc is guaranteed
139 					 * to be at an address < 16Mb). */
140 
141 	int result;		/* Status code from lower level driver */
142 	int flags;		/* Command flags */
143 
144 	unsigned char tag;	/* SCSI-II queued command tag */
145 };
146 
147 /*
148  * Return the driver private allocation behind the command.
149  * Only works if cmd_size is set in the host template.
150  */
151 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
152 {
153 	return cmd + 1;
154 }
155 
156 /* make sure not to use it with passthrough commands */
157 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
158 {
159 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
160 }
161 
162 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
163 extern void scsi_put_command(struct scsi_cmnd *);
164 extern void scsi_finish_command(struct scsi_cmnd *cmd);
165 
166 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
167 				 size_t *offset, size_t *len);
168 extern void scsi_kunmap_atomic_sg(void *virt);
169 
170 extern int scsi_init_io(struct scsi_cmnd *cmd);
171 extern void scsi_initialize_rq(struct request *rq);
172 
173 extern int scsi_dma_map(struct scsi_cmnd *cmd);
174 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
175 
176 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
177 {
178 	return cmd->sdb.table.nents;
179 }
180 
181 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
182 {
183 	return cmd->sdb.table.sgl;
184 }
185 
186 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
187 {
188 	return cmd->sdb.length;
189 }
190 
191 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
192 {
193 	cmd->sdb.resid = resid;
194 }
195 
196 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
197 {
198 	return cmd->sdb.resid;
199 }
200 
201 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
202 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
203 
204 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
205 {
206 	return blk_bidi_rq(cmd->request) &&
207 		(cmd->request->next_rq->special != NULL);
208 }
209 
210 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
211 {
212 	return scsi_bidi_cmnd(cmd) ?
213 		cmd->request->next_rq->special : &cmd->sdb;
214 }
215 
216 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
217 {
218 	return &cmd->sdb;
219 }
220 
221 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
222 					   void *buf, int buflen)
223 {
224 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
225 				   buf, buflen);
226 }
227 
228 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
229 					 void *buf, int buflen)
230 {
231 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
232 				 buf, buflen);
233 }
234 
235 /*
236  * The operations below are hints that tell the controller driver how
237  * to handle I/Os with DIF or similar types of protection information.
238  */
239 enum scsi_prot_operations {
240 	/* Normal I/O */
241 	SCSI_PROT_NORMAL = 0,
242 
243 	/* OS-HBA: Protected, HBA-Target: Unprotected */
244 	SCSI_PROT_READ_INSERT,
245 	SCSI_PROT_WRITE_STRIP,
246 
247 	/* OS-HBA: Unprotected, HBA-Target: Protected */
248 	SCSI_PROT_READ_STRIP,
249 	SCSI_PROT_WRITE_INSERT,
250 
251 	/* OS-HBA: Protected, HBA-Target: Protected */
252 	SCSI_PROT_READ_PASS,
253 	SCSI_PROT_WRITE_PASS,
254 };
255 
256 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
257 {
258 	scmd->prot_op = op;
259 }
260 
261 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
262 {
263 	return scmd->prot_op;
264 }
265 
266 enum scsi_prot_flags {
267 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
268 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
269 	SCSI_PROT_REF_CHECK		= 1 << 2,
270 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
271 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
272 };
273 
274 /*
275  * The controller usually does not know anything about the target it
276  * is communicating with.  However, when DIX is enabled the controller
277  * must be know target type so it can verify the protection
278  * information passed along with the I/O.
279  */
280 enum scsi_prot_target_type {
281 	SCSI_PROT_DIF_TYPE0 = 0,
282 	SCSI_PROT_DIF_TYPE1,
283 	SCSI_PROT_DIF_TYPE2,
284 	SCSI_PROT_DIF_TYPE3,
285 };
286 
287 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
288 {
289 	scmd->prot_type = type;
290 }
291 
292 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
293 {
294 	return scmd->prot_type;
295 }
296 
297 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
298 {
299 	return blk_rq_pos(scmd->request);
300 }
301 
302 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
303 {
304 	return scmd->device->sector_size;
305 }
306 
307 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
308 {
309 	return blk_rq_pos(scmd->request) >>
310 		(ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
311 }
312 
313 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
314 {
315 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
316 }
317 
318 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
319 {
320 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
321 }
322 
323 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
324 {
325 	return cmd->prot_sdb;
326 }
327 
328 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
329 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
330 
331 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
332 {
333 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
334 }
335 
336 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
337 {
338 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
339 }
340 
341 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
342 {
343 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
344 }
345 
346 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
347 {
348 	unsigned int xfer_len = scsi_out(scmd)->length;
349 	unsigned int prot_interval = scsi_prot_interval(scmd);
350 
351 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
352 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
353 
354 	return xfer_len;
355 }
356 
357 #endif /* _SCSI_SCSI_CMND_H */
358