Root/include/scsi/scsi_cmnd.h

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 */
306

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