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/include/scsi/scsi_cmnd.h

https://bitbucket.org/thekraven/iscream_thunderc-2.6.35
C++ Header | 305 lines | 183 code | 59 blank | 63 comment | 1 complexity | 3cdbc5afbc45f2949073701fc98b3964 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  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
 11struct Scsi_Host;
 12struct scsi_device;
 13
 14/*
 15 * MAX_COMMAND_SIZE is:
 16 * The longest fixed-length SCSI CDB as per the SCSI standard.
 17 * fixed-length means: commands that their size can be determined
 18 * by their opcode and the CDB does not carry a length specifier, (unlike
 19 * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
 20 * true and the SCSI standard also defines extended commands and
 21 * vendor specific commands that can be bigger than 16 bytes. The kernel
 22 * will support these using the same infrastructure used for VARLEN CDB's.
 23 * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
 24 * supports without specifying a cmd_len by ULD's
 25 */
 26#define MAX_COMMAND_SIZE 16
 27#if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
 28# error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
 29#endif
 30
 31struct scsi_data_buffer {
 32	struct sg_table table;
 33	unsigned length;
 34	int resid;
 35};
 36
 37/* embedded in scsi_cmnd */
 38struct scsi_pointer {
 39	char *ptr;		/* data pointer */
 40	int this_residual;	/* left in this buffer */
 41	struct scatterlist *buffer;	/* which buffer */
 42	int buffers_residual;	/* how many buffers left */
 43
 44        dma_addr_t dma_handle;
 45
 46	volatile int Status;
 47	volatile int Message;
 48	volatile int have_data_in;
 49	volatile int sent_command;
 50	volatile int phase;
 51};
 52
 53struct scsi_cmnd {
 54	struct scsi_device *device;
 55	struct list_head list;  /* scsi_cmnd participates in queue lists */
 56	struct list_head eh_entry; /* entry for the host eh_cmd_q */
 57	int eh_eflags;		/* Used by error handlr */
 58
 59	/*
 60	 * A SCSI Command is assigned a nonzero serial_number before passed
 61	 * to the driver's queue command function.  The serial_number is
 62	 * cleared when scsi_done is entered indicating that the command
 63	 * has been completed.  It is a bug for LLDDs to use this number
 64	 * for purposes other than printk (and even that is only useful
 65	 * for debugging).
 66	 */
 67	unsigned long serial_number;
 68
 69	/*
 70	 * This is set to jiffies as it was when the command was first
 71	 * allocated.  It is used to time how long the command has
 72	 * been outstanding
 73	 */
 74	unsigned long jiffies_at_alloc;
 75
 76	int retries;
 77	int allowed;
 78
 79	unsigned char prot_op;
 80	unsigned char prot_type;
 81
 82	unsigned short cmd_len;
 83	enum dma_data_direction sc_data_direction;
 84
 85	/* These elements define the operation we are about to perform */
 86	unsigned char *cmnd;
 87
 88
 89	/* These elements define the operation we ultimately want to perform */
 90	struct scsi_data_buffer sdb;
 91	struct scsi_data_buffer *prot_sdb;
 92
 93	unsigned underflow;	/* Return error if less than
 94				   this amount is transferred */
 95
 96	unsigned transfersize;	/* How much we are guaranteed to
 97				   transfer with each SCSI transfer
 98				   (ie, between disconnect / 
 99				   reconnects.   Probably == sector
100				   size */
101
102	struct request *request;	/* The command we are
103				   	   working on */
104
105#define SCSI_SENSE_BUFFERSIZE 	96
106	unsigned char *sense_buffer;
107				/* obtained by REQUEST SENSE when
108				 * CHECK CONDITION is received on original
109				 * command (auto-sense) */
110
111	/* Low-level done function - can be used by low-level driver to point
112	 *        to completion function.  Not used by mid/upper level code. */
113	void (*scsi_done) (struct scsi_cmnd *);
114
115	/*
116	 * The following fields can be written to by the host specific code. 
117	 * Everything else should be left alone. 
118	 */
119	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
120
121	unsigned char *host_scribble;	/* The host adapter is allowed to
122					 * call scsi_malloc and get some memory
123					 * and hang it here.  The host adapter
124					 * is also expected to call scsi_free
125					 * to release this memory.  (The memory
126					 * obtained by scsi_malloc is guaranteed
127					 * to be at an address < 16Mb). */
128
129	int result;		/* Status code from lower level driver */
130
131	unsigned char tag;	/* SCSI-II queued command tag */
132};
133
134extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
135extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
136extern void scsi_put_command(struct scsi_cmnd *);
137extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
138			       struct device *);
139extern void scsi_finish_command(struct scsi_cmnd *cmd);
140
141extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
142				 size_t *offset, size_t *len);
143extern void scsi_kunmap_atomic_sg(void *virt);
144
145extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
146extern void scsi_release_buffers(struct scsi_cmnd *cmd);
147
148extern int scsi_dma_map(struct scsi_cmnd *cmd);
149extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
150
151struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
152void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
153
154static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
155{
156	return cmd->sdb.table.nents;
157}
158
159static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
160{
161	return cmd->sdb.table.sgl;
162}
163
164static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
165{
166	return cmd->sdb.length;
167}
168
169static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
170{
171	cmd->sdb.resid = resid;
172}
173
174static inline int scsi_get_resid(struct scsi_cmnd *cmd)
175{
176	return cmd->sdb.resid;
177}
178
179#define scsi_for_each_sg(cmd, sg, nseg, __i)			\
180	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
181
182static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
183{
184	return blk_bidi_rq(cmd->request) &&
185		(cmd->request->next_rq->special != NULL);
186}
187
188static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
189{
190	return scsi_bidi_cmnd(cmd) ?
191		cmd->request->next_rq->special : &cmd->sdb;
192}
193
194static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
195{
196	return &cmd->sdb;
197}
198
199static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
200					   void *buf, int buflen)
201{
202	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
203				   buf, buflen);
204}
205
206static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
207					 void *buf, int buflen)
208{
209	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
210				 buf, buflen);
211}
212
213/*
214 * The operations below are hints that tell the controller driver how
215 * to handle I/Os with DIF or similar types of protection information.
216 */
217enum scsi_prot_operations {
218	/* Normal I/O */
219	SCSI_PROT_NORMAL = 0,
220
221	/* OS-HBA: Protected, HBA-Target: Unprotected */
222	SCSI_PROT_READ_INSERT,
223	SCSI_PROT_WRITE_STRIP,
224
225	/* OS-HBA: Unprotected, HBA-Target: Protected */
226	SCSI_PROT_READ_STRIP,
227	SCSI_PROT_WRITE_INSERT,
228
229	/* OS-HBA: Protected, HBA-Target: Protected */
230	SCSI_PROT_READ_PASS,
231	SCSI_PROT_WRITE_PASS,
232};
233
234static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
235{
236	scmd->prot_op = op;
237}
238
239static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
240{
241	return scmd->prot_op;
242}
243
244/*
245 * The controller usually does not know anything about the target it
246 * is communicating with.  However, when DIX is enabled the controller
247 * must be know target type so it can verify the protection
248 * information passed along with the I/O.
249 */
250enum scsi_prot_target_type {
251	SCSI_PROT_DIF_TYPE0 = 0,
252	SCSI_PROT_DIF_TYPE1,
253	SCSI_PROT_DIF_TYPE2,
254	SCSI_PROT_DIF_TYPE3,
255};
256
257static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
258{
259	scmd->prot_type = type;
260}
261
262static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
263{
264	return scmd->prot_type;
265}
266
267static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
268{
269	return blk_rq_pos(scmd->request);
270}
271
272static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
273{
274	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
275}
276
277static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
278{
279	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
280}
281
282static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
283{
284	return cmd->prot_sdb;
285}
286
287#define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
288	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
289
290static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
291{
292	cmd->result |= status << 8;
293}
294
295static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
296{
297	cmd->result |= status << 16;
298}
299
300static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
301{
302	cmd->result |= status << 24;
303}
304
305#endif /* _SCSI_SCSI_CMND_H */