xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 #ifndef _SCSI_SCSI_CMND_H
2 #define _SCSI_SCSI_CMND_H
3 
4 #include <linux/dma-mapping.h>
5 #include <linux/list.h>
6 #include <linux/types.h>
7 #include <linux/timer.h>
8 #include <linux/scatterlist.h>
9 
10 struct request;
11 struct scatterlist;
12 struct Scsi_Host;
13 struct scsi_device;
14 
15 
16 /* embedded in scsi_cmnd */
17 struct scsi_pointer {
18 	char *ptr;		/* data pointer */
19 	int this_residual;	/* left in this buffer */
20 	struct scatterlist *buffer;	/* which buffer */
21 	int buffers_residual;	/* how many buffers left */
22 
23         dma_addr_t dma_handle;
24 
25 	volatile int Status;
26 	volatile int Message;
27 	volatile int have_data_in;
28 	volatile int sent_command;
29 	volatile int phase;
30 };
31 
32 struct scsi_cmnd {
33 	struct scsi_device *device;
34 	struct list_head list;  /* scsi_cmnd participates in queue lists */
35 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
36 	int eh_eflags;		/* Used by error handlr */
37 
38 	/*
39 	 * A SCSI Command is assigned a nonzero serial_number before passed
40 	 * to the driver's queue command function.  The serial_number is
41 	 * cleared when scsi_done is entered indicating that the command
42 	 * has been completed.  It is a bug for LLDDs to use this number
43 	 * for purposes other than printk (and even that is only useful
44 	 * for debugging).
45 	 */
46 	unsigned long serial_number;
47 
48 	/*
49 	 * This is set to jiffies as it was when the command was first
50 	 * allocated.  It is used to time how long the command has
51 	 * been outstanding
52 	 */
53 	unsigned long jiffies_at_alloc;
54 
55 	int retries;
56 	int allowed;
57 	int timeout_per_command;
58 
59 	unsigned char cmd_len;
60 	enum dma_data_direction sc_data_direction;
61 
62 	/* These elements define the operation we are about to perform */
63 #define MAX_COMMAND_SIZE	16
64 	unsigned char cmnd[MAX_COMMAND_SIZE];
65 	unsigned request_bufflen;	/* Actual request size */
66 
67 	struct timer_list eh_timeout;	/* Used to time out the command. */
68 	void *request_buffer;		/* Actual requested buffer */
69 
70 	/* These elements define the operation we ultimately want to perform */
71 	unsigned short use_sg;	/* Number of pieces of scatter-gather */
72 	unsigned short __use_sg;
73 
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 	int resid;		/* Number of bytes requested to be
84 				   transferred less actual number
85 				   transferred (0 if not supported) */
86 
87 	struct request *request;	/* The command we are
88 				   	   working on */
89 
90 #define SCSI_SENSE_BUFFERSIZE 	96
91 	unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];
92 				/* obtained by REQUEST SENSE when
93 				 * CHECK CONDITION is received on original
94 				 * command (auto-sense) */
95 
96 	/* Low-level done function - can be used by low-level driver to point
97 	 *        to completion function.  Not used by mid/upper level code. */
98 	void (*scsi_done) (struct scsi_cmnd *);
99 
100 	/*
101 	 * The following fields can be written to by the host specific code.
102 	 * Everything else should be left alone.
103 	 */
104 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
105 
106 	unsigned char *host_scribble;	/* The host adapter is allowed to
107 					 * call scsi_malloc and get some memory
108 					 * and hang it here.  The host adapter
109 					 * is also expected to call scsi_free
110 					 * to release this memory.  (The memory
111 					 * obtained by scsi_malloc is guaranteed
112 					 * to be at an address < 16Mb). */
113 
114 	int result;		/* Status code from lower level driver */
115 
116 	unsigned char tag;	/* SCSI-II queued command tag */
117 };
118 
119 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
120 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
121 extern void scsi_put_command(struct scsi_cmnd *);
122 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
123 			       struct device *);
124 extern void scsi_finish_command(struct scsi_cmnd *cmd);
125 extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
126 
127 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
128 				 size_t *offset, size_t *len);
129 extern void scsi_kunmap_atomic_sg(void *virt);
130 
131 extern struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t);
132 extern void scsi_free_sgtable(struct scsi_cmnd *);
133 
134 extern int scsi_dma_map(struct scsi_cmnd *cmd);
135 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
136 
137 #define scsi_sg_count(cmd) ((cmd)->use_sg)
138 #define scsi_sglist(cmd) ((struct scatterlist *)(cmd)->request_buffer)
139 #define scsi_bufflen(cmd) ((cmd)->request_bufflen)
140 
141 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
142 {
143 	cmd->resid = resid;
144 }
145 
146 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
147 {
148 	return cmd->resid;
149 }
150 
151 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
152 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
153 
154 #endif /* _SCSI_SCSI_CMND_H */
155