xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision 643d1f7f)
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 
11 struct Scsi_Host;
12 struct scsi_device;
13 
14 struct scsi_data_buffer {
15 	struct sg_table table;
16 	unsigned length;
17 	int resid;
18 };
19 
20 /* embedded in scsi_cmnd */
21 struct scsi_pointer {
22 	char *ptr;		/* data pointer */
23 	int this_residual;	/* left in this buffer */
24 	struct scatterlist *buffer;	/* which buffer */
25 	int buffers_residual;	/* how many buffers left */
26 
27         dma_addr_t dma_handle;
28 
29 	volatile int Status;
30 	volatile int Message;
31 	volatile int have_data_in;
32 	volatile int sent_command;
33 	volatile int phase;
34 };
35 
36 struct scsi_cmnd {
37 	struct scsi_device *device;
38 	struct list_head list;  /* scsi_cmnd participates in queue lists */
39 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
40 	int eh_eflags;		/* Used by error handlr */
41 
42 	/*
43 	 * A SCSI Command is assigned a nonzero serial_number before passed
44 	 * to the driver's queue command function.  The serial_number is
45 	 * cleared when scsi_done is entered indicating that the command
46 	 * has been completed.  It is a bug for LLDDs to use this number
47 	 * for purposes other than printk (and even that is only useful
48 	 * for debugging).
49 	 */
50 	unsigned long serial_number;
51 
52 	/*
53 	 * This is set to jiffies as it was when the command was first
54 	 * allocated.  It is used to time how long the command has
55 	 * been outstanding
56 	 */
57 	unsigned long jiffies_at_alloc;
58 
59 	int retries;
60 	int allowed;
61 	int timeout_per_command;
62 
63 	unsigned char cmd_len;
64 	enum dma_data_direction sc_data_direction;
65 
66 	/* These elements define the operation we are about to perform */
67 #define MAX_COMMAND_SIZE	16
68 	unsigned char cmnd[MAX_COMMAND_SIZE];
69 
70 	struct timer_list eh_timeout;	/* Used to time out the command. */
71 
72 	/* These elements define the operation we ultimately want to perform */
73 	struct scsi_data_buffer sdb;
74 	unsigned underflow;	/* Return error if less than
75 				   this amount is transferred */
76 
77 	unsigned transfersize;	/* How much we are guaranteed to
78 				   transfer with each SCSI transfer
79 				   (ie, between disconnect /
80 				   reconnects.   Probably == sector
81 				   size */
82 
83 	struct request *request;	/* The command we are
84 				   	   working on */
85 
86 #define SCSI_SENSE_BUFFERSIZE 	96
87 	unsigned char *sense_buffer;
88 				/* obtained by REQUEST SENSE when
89 				 * CHECK CONDITION is received on original
90 				 * command (auto-sense) */
91 
92 	/* Low-level done function - can be used by low-level driver to point
93 	 *        to completion function.  Not used by mid/upper level code. */
94 	void (*scsi_done) (struct scsi_cmnd *);
95 
96 	/*
97 	 * The following fields can be written to by the host specific code.
98 	 * Everything else should be left alone.
99 	 */
100 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
101 
102 	unsigned char *host_scribble;	/* The host adapter is allowed to
103 					 * call scsi_malloc and get some memory
104 					 * and hang it here.  The host adapter
105 					 * is also expected to call scsi_free
106 					 * to release this memory.  (The memory
107 					 * obtained by scsi_malloc is guaranteed
108 					 * to be at an address < 16Mb). */
109 
110 	int result;		/* Status code from lower level driver */
111 
112 	unsigned char tag;	/* SCSI-II queued command tag */
113 };
114 
115 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
116 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
117 extern void scsi_put_command(struct scsi_cmnd *);
118 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
119 			       struct device *);
120 extern void scsi_finish_command(struct scsi_cmnd *cmd);
121 extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
122 
123 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
124 				 size_t *offset, size_t *len);
125 extern void scsi_kunmap_atomic_sg(void *virt);
126 
127 extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
128 extern void scsi_release_buffers(struct scsi_cmnd *cmd);
129 
130 extern int scsi_dma_map(struct scsi_cmnd *cmd);
131 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
132 
133 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
134 {
135 	return cmd->sdb.table.nents;
136 }
137 
138 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
139 {
140 	return cmd->sdb.table.sgl;
141 }
142 
143 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
144 {
145 	return cmd->sdb.length;
146 }
147 
148 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
149 {
150 	cmd->sdb.resid = resid;
151 }
152 
153 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
154 {
155 	return cmd->sdb.resid;
156 }
157 
158 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
159 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
160 
161 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
162 {
163 	return blk_bidi_rq(cmd->request) &&
164 		(cmd->request->next_rq->special != NULL);
165 }
166 
167 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
168 {
169 	return scsi_bidi_cmnd(cmd) ?
170 		cmd->request->next_rq->special : &cmd->sdb;
171 }
172 
173 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
174 {
175 	return &cmd->sdb;
176 }
177 
178 #endif /* _SCSI_SCSI_CMND_H */
179