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
12struct Scsi_Host;
13struct 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
34struct scsi_data_buffer {
35	struct sg_table table;
36	unsigned length;
37	int resid;
38};
39
40/* embedded in scsi_cmnd */
41struct 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/* for scmd->flags */
57#define SCMD_TAGGED		(1 << 0)
58
59struct scsi_cmnd {
60	struct scsi_device *device;
61	struct list_head list;  /* scsi_cmnd participates in queue lists */
62	struct list_head eh_entry; /* entry for the host eh_cmd_q */
63	struct delayed_work abort_work;
64	int eh_eflags;		/* Used by error handlr */
65
66	/*
67	 * A SCSI Command is assigned a nonzero serial_number before passed
68	 * to the driver's queue command function.  The serial_number is
69	 * cleared when scsi_done is entered indicating that the command
70	 * has been completed.  It is a bug for LLDDs to use this number
71	 * for purposes other than printk (and even that is only useful
72	 * for debugging).
73	 */
74	unsigned long serial_number;
75
76	/*
77	 * This is set to jiffies as it was when the command was first
78	 * allocated.  It is used to time how long the command has
79	 * been outstanding
80	 */
81	unsigned long jiffies_at_alloc;
82
83	int retries;
84	int allowed;
85
86	unsigned char prot_op;
87	unsigned char prot_type;
88	unsigned char prot_flags;
89
90	unsigned short cmd_len;
91	enum dma_data_direction sc_data_direction;
92
93	/* These elements define the operation we are about to perform */
94	unsigned char *cmnd;
95
96
97	/* These elements define the operation we ultimately want to perform */
98	struct scsi_data_buffer sdb;
99	struct scsi_data_buffer *prot_sdb;
100
101	unsigned underflow;	/* Return error if less than
102				   this amount is transferred */
103
104	unsigned transfersize;	/* How much we are guaranteed to
105				   transfer with each SCSI transfer
106				   (ie, between disconnect /
107				   reconnects.   Probably == sector
108				   size */
109
110	struct request *request;	/* The command we are
111				   	   working on */
112
113#define SCSI_SENSE_BUFFERSIZE 	96
114	unsigned char *sense_buffer;
115				/* obtained by REQUEST SENSE when
116				 * CHECK CONDITION is received on original
117				 * command (auto-sense) */
118
119	/* Low-level done function - can be used by low-level driver to point
120	 *        to completion function.  Not used by mid/upper level code. */
121	void (*scsi_done) (struct scsi_cmnd *);
122
123	/*
124	 * The following fields can be written to by the host specific code.
125	 * Everything else should be left alone.
126	 */
127	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
128
129	unsigned char *host_scribble;	/* The host adapter is allowed to
130					 * call scsi_malloc and get some memory
131					 * and hang it here.  The host adapter
132					 * is also expected to call scsi_free
133					 * to release this memory.  (The memory
134					 * obtained by scsi_malloc is guaranteed
135					 * to be at an address < 16Mb). */
136
137	int result;		/* Status code from lower level driver */
138	int flags;		/* Command flags */
139
140	unsigned char tag;	/* SCSI-II queued command tag */
141};
142
143/*
144 * Return the driver private allocation behind the command.
145 * Only works if cmd_size is set in the host template.
146 */
147static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
148{
149	return cmd + 1;
150}
151
152/* make sure not to use it with REQ_TYPE_BLOCK_PC commands */
153static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
154{
155	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
156}
157
158extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
159extern void scsi_put_command(struct scsi_cmnd *);
160extern void scsi_finish_command(struct scsi_cmnd *cmd);
161
162extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
163				 size_t *offset, size_t *len);
164extern void scsi_kunmap_atomic_sg(void *virt);
165
166extern int scsi_init_io(struct scsi_cmnd *cmd);
167
168extern int scsi_dma_map(struct scsi_cmnd *cmd);
169extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
170
171static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
172{
173	return cmd->sdb.table.nents;
174}
175
176static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
177{
178	return cmd->sdb.table.sgl;
179}
180
181static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
182{
183	return cmd->sdb.length;
184}
185
186static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
187{
188	cmd->sdb.resid = resid;
189}
190
191static inline int scsi_get_resid(struct scsi_cmnd *cmd)
192{
193	return cmd->sdb.resid;
194}
195
196#define scsi_for_each_sg(cmd, sg, nseg, __i)			\
197	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
198
199static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
200{
201	return blk_bidi_rq(cmd->request) &&
202		(cmd->request->next_rq->special != NULL);
203}
204
205static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
206{
207	return scsi_bidi_cmnd(cmd) ?
208		cmd->request->next_rq->special : &cmd->sdb;
209}
210
211static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
212{
213	return &cmd->sdb;
214}
215
216static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
217					   void *buf, int buflen)
218{
219	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
220				   buf, buflen);
221}
222
223static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
224					 void *buf, int buflen)
225{
226	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
227				 buf, buflen);
228}
229
230/*
231 * The operations below are hints that tell the controller driver how
232 * to handle I/Os with DIF or similar types of protection information.
233 */
234enum scsi_prot_operations {
235	/* Normal I/O */
236	SCSI_PROT_NORMAL = 0,
237
238	/* OS-HBA: Protected, HBA-Target: Unprotected */
239	SCSI_PROT_READ_INSERT,
240	SCSI_PROT_WRITE_STRIP,
241
242	/* OS-HBA: Unprotected, HBA-Target: Protected */
243	SCSI_PROT_READ_STRIP,
244	SCSI_PROT_WRITE_INSERT,
245
246	/* OS-HBA: Protected, HBA-Target: Protected */
247	SCSI_PROT_READ_PASS,
248	SCSI_PROT_WRITE_PASS,
249};
250
251static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
252{
253	scmd->prot_op = op;
254}
255
256static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
257{
258	return scmd->prot_op;
259}
260
261enum scsi_prot_flags {
262	SCSI_PROT_TRANSFER_PI		= 1 << 0,
263	SCSI_PROT_GUARD_CHECK		= 1 << 1,
264	SCSI_PROT_REF_CHECK		= 1 << 2,
265	SCSI_PROT_REF_INCREMENT		= 1 << 3,
266	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
267};
268
269/*
270 * The controller usually does not know anything about the target it
271 * is communicating with.  However, when DIX is enabled the controller
272 * must be know target type so it can verify the protection
273 * information passed along with the I/O.
274 */
275enum scsi_prot_target_type {
276	SCSI_PROT_DIF_TYPE0 = 0,
277	SCSI_PROT_DIF_TYPE1,
278	SCSI_PROT_DIF_TYPE2,
279	SCSI_PROT_DIF_TYPE3,
280};
281
282static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
283{
284	scmd->prot_type = type;
285}
286
287static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
288{
289	return scmd->prot_type;
290}
291
292static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
293{
294	return blk_rq_pos(scmd->request);
295}
296
297static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
298{
299	return scmd->device->sector_size;
300}
301
302static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
303{
304	return blk_rq_pos(scmd->request) >>
305		(ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
306}
307
308static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
309{
310	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
311}
312
313static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
314{
315	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
316}
317
318static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
319{
320	return cmd->prot_sdb;
321}
322
323#define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
324	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
325
326static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
327{
328	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
329}
330
331static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
332{
333	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
334}
335
336static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
337{
338	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
339}
340
341static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
342{
343	unsigned int xfer_len = scsi_out(scmd)->length;
344	unsigned int prot_interval = scsi_prot_interval(scmd);
345
346	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
347		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
348
349	return xfer_len;
350}
351
352#endif /* _SCSI_SCSI_CMND_H */
353