xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision 82e6fdd6)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _SCSI_SCSI_CMND_H
3 #define _SCSI_SCSI_CMND_H
4 
5 #include <linux/dma-mapping.h>
6 #include <linux/blkdev.h>
7 #include <linux/list.h>
8 #include <linux/types.h>
9 #include <linux/timer.h>
10 #include <linux/scatterlist.h>
11 #include <scsi/scsi_device.h>
12 #include <scsi/scsi_request.h>
13 
14 struct Scsi_Host;
15 struct scsi_driver;
16 
17 #include <scsi/scsi_device.h>
18 
19 /*
20  * MAX_COMMAND_SIZE is:
21  * The longest fixed-length SCSI CDB as per the SCSI standard.
22  * fixed-length means: commands that their size can be determined
23  * by their opcode and the CDB does not carry a length specifier, (unlike
24  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
25  * true and the SCSI standard also defines extended commands and
26  * vendor specific commands that can be bigger than 16 bytes. The kernel
27  * will support these using the same infrastructure used for VARLEN CDB's.
28  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
29  * supports without specifying a cmd_len by ULD's
30  */
31 #define MAX_COMMAND_SIZE 16
32 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
33 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
34 #endif
35 
36 struct scsi_data_buffer {
37 	struct sg_table table;
38 	unsigned length;
39 	int resid;
40 };
41 
42 /* embedded in scsi_cmnd */
43 struct scsi_pointer {
44 	char *ptr;		/* data pointer */
45 	int this_residual;	/* left in this buffer */
46 	struct scatterlist *buffer;	/* which buffer */
47 	int buffers_residual;	/* how many buffers left */
48 
49         dma_addr_t dma_handle;
50 
51 	volatile int Status;
52 	volatile int Message;
53 	volatile int have_data_in;
54 	volatile int sent_command;
55 	volatile int phase;
56 };
57 
58 /* for scmd->flags */
59 #define SCMD_TAGGED		(1 << 0)
60 #define SCMD_UNCHECKED_ISA_DMA	(1 << 1)
61 #define SCMD_INITIALIZED	(1 << 2)
62 /* flags preserved across unprep / reprep */
63 #define SCMD_PRESERVED_FLAGS	(SCMD_UNCHECKED_ISA_DMA | SCMD_INITIALIZED)
64 
65 struct scsi_cmnd {
66 	struct scsi_request req;
67 	struct scsi_device *device;
68 	struct list_head list;  /* scsi_cmnd participates in queue lists */
69 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
70 	struct delayed_work abort_work;
71 	int eh_eflags;		/* Used by error handlr */
72 
73 	/*
74 	 * A SCSI Command is assigned a nonzero serial_number before passed
75 	 * to the driver's queue command function.  The serial_number is
76 	 * cleared when scsi_done is entered indicating that the command
77 	 * has been completed.  It is a bug for LLDDs to use this number
78 	 * for purposes other than printk (and even that is only useful
79 	 * for debugging).
80 	 */
81 	unsigned long serial_number;
82 
83 	/*
84 	 * This is set to jiffies as it was when the command was first
85 	 * allocated.  It is used to time how long the command has
86 	 * been outstanding
87 	 */
88 	unsigned long jiffies_at_alloc;
89 
90 	int retries;
91 	int allowed;
92 
93 	unsigned char prot_op;
94 	unsigned char prot_type;
95 	unsigned char prot_flags;
96 
97 	unsigned short cmd_len;
98 	enum dma_data_direction sc_data_direction;
99 
100 	/* These elements define the operation we are about to perform */
101 	unsigned char *cmnd;
102 
103 
104 	/* These elements define the operation we ultimately want to perform */
105 	struct scsi_data_buffer sdb;
106 	struct scsi_data_buffer *prot_sdb;
107 
108 	unsigned underflow;	/* Return error if less than
109 				   this amount is transferred */
110 
111 	unsigned transfersize;	/* How much we are guaranteed to
112 				   transfer with each SCSI transfer
113 				   (ie, between disconnect /
114 				   reconnects.   Probably == sector
115 				   size */
116 
117 	struct request *request;	/* The command we are
118 				   	   working on */
119 
120 #define SCSI_SENSE_BUFFERSIZE 	96
121 	unsigned char *sense_buffer;
122 				/* obtained by REQUEST SENSE when
123 				 * CHECK CONDITION is received on original
124 				 * command (auto-sense) */
125 
126 	/* Low-level done function - can be used by low-level driver to point
127 	 *        to completion function.  Not used by mid/upper level code. */
128 	void (*scsi_done) (struct scsi_cmnd *);
129 
130 	/*
131 	 * The following fields can be written to by the host specific code.
132 	 * Everything else should be left alone.
133 	 */
134 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
135 
136 	unsigned char *host_scribble;	/* The host adapter is allowed to
137 					 * call scsi_malloc and get some memory
138 					 * and hang it here.  The host adapter
139 					 * is also expected to call scsi_free
140 					 * to release this memory.  (The memory
141 					 * obtained by scsi_malloc is guaranteed
142 					 * to be at an address < 16Mb). */
143 
144 	int result;		/* Status code from lower level driver */
145 	int flags;		/* Command flags */
146 
147 	unsigned char tag;	/* SCSI-II queued command tag */
148 };
149 
150 /*
151  * Return the driver private allocation behind the command.
152  * Only works if cmd_size is set in the host template.
153  */
154 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
155 {
156 	return cmd + 1;
157 }
158 
159 /* make sure not to use it with passthrough commands */
160 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
161 {
162 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
163 }
164 
165 extern void scsi_put_command(struct scsi_cmnd *);
166 extern void scsi_finish_command(struct scsi_cmnd *cmd);
167 
168 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
169 				 size_t *offset, size_t *len);
170 extern void scsi_kunmap_atomic_sg(void *virt);
171 
172 extern int scsi_init_io(struct scsi_cmnd *cmd);
173 
174 extern int scsi_dma_map(struct scsi_cmnd *cmd);
175 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
176 
177 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
178 {
179 	return cmd->sdb.table.nents;
180 }
181 
182 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
183 {
184 	return cmd->sdb.table.sgl;
185 }
186 
187 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
188 {
189 	return cmd->sdb.length;
190 }
191 
192 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
193 {
194 	cmd->sdb.resid = resid;
195 }
196 
197 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
198 {
199 	return cmd->sdb.resid;
200 }
201 
202 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
203 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
204 
205 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
206 {
207 	return blk_bidi_rq(cmd->request) &&
208 		(cmd->request->next_rq->special != NULL);
209 }
210 
211 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
212 {
213 	return scsi_bidi_cmnd(cmd) ?
214 		cmd->request->next_rq->special : &cmd->sdb;
215 }
216 
217 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
218 {
219 	return &cmd->sdb;
220 }
221 
222 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
223 					   void *buf, int buflen)
224 {
225 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
226 				   buf, buflen);
227 }
228 
229 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
230 					 void *buf, int buflen)
231 {
232 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
233 				 buf, buflen);
234 }
235 
236 /*
237  * The operations below are hints that tell the controller driver how
238  * to handle I/Os with DIF or similar types of protection information.
239  */
240 enum scsi_prot_operations {
241 	/* Normal I/O */
242 	SCSI_PROT_NORMAL = 0,
243 
244 	/* OS-HBA: Protected, HBA-Target: Unprotected */
245 	SCSI_PROT_READ_INSERT,
246 	SCSI_PROT_WRITE_STRIP,
247 
248 	/* OS-HBA: Unprotected, HBA-Target: Protected */
249 	SCSI_PROT_READ_STRIP,
250 	SCSI_PROT_WRITE_INSERT,
251 
252 	/* OS-HBA: Protected, HBA-Target: Protected */
253 	SCSI_PROT_READ_PASS,
254 	SCSI_PROT_WRITE_PASS,
255 };
256 
257 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
258 {
259 	scmd->prot_op = op;
260 }
261 
262 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
263 {
264 	return scmd->prot_op;
265 }
266 
267 enum scsi_prot_flags {
268 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
269 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
270 	SCSI_PROT_REF_CHECK		= 1 << 2,
271 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
272 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
273 };
274 
275 /*
276  * The controller usually does not know anything about the target it
277  * is communicating with.  However, when DIX is enabled the controller
278  * must be know target type so it can verify the protection
279  * information passed along with the I/O.
280  */
281 enum scsi_prot_target_type {
282 	SCSI_PROT_DIF_TYPE0 = 0,
283 	SCSI_PROT_DIF_TYPE1,
284 	SCSI_PROT_DIF_TYPE2,
285 	SCSI_PROT_DIF_TYPE3,
286 };
287 
288 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
289 {
290 	scmd->prot_type = type;
291 }
292 
293 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
294 {
295 	return scmd->prot_type;
296 }
297 
298 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
299 {
300 	return blk_rq_pos(scmd->request);
301 }
302 
303 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
304 {
305 	return scmd->device->sector_size;
306 }
307 
308 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
309 {
310 	return blk_rq_pos(scmd->request) >>
311 		(ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
312 }
313 
314 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
315 {
316 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
317 }
318 
319 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
320 {
321 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
322 }
323 
324 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
325 {
326 	return cmd->prot_sdb;
327 }
328 
329 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
330 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
331 
332 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
333 {
334 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
335 }
336 
337 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
338 {
339 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
340 }
341 
342 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
343 {
344 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
345 }
346 
347 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
348 {
349 	unsigned int xfer_len = scsi_out(scmd)->length;
350 	unsigned int prot_interval = scsi_prot_interval(scmd);
351 
352 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
353 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
354 
355 	return xfer_len;
356 }
357 
358 #endif /* _SCSI_SCSI_CMND_H */
359