xref: /linux/include/scsi/scsi_cmnd.h (revision 6e8331ac6973435b1e7604c30f2ad394035b46e1)
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 
9 struct request;
10 struct scatterlist;
11 struct scsi_device;
12 
13 
14 /* embedded in scsi_cmnd */
15 struct scsi_pointer {
16 	char *ptr;		/* data pointer */
17 	int this_residual;	/* left in this buffer */
18 	struct scatterlist *buffer;	/* which buffer */
19 	int buffers_residual;	/* how many buffers left */
20 
21         dma_addr_t dma_handle;
22 
23 	volatile int Status;
24 	volatile int Message;
25 	volatile int have_data_in;
26 	volatile int sent_command;
27 	volatile int phase;
28 };
29 
30 struct scsi_cmnd {
31 	struct scsi_device *device;
32 	struct list_head list;  /* scsi_cmnd participates in queue lists */
33 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
34 	int eh_eflags;		/* Used by error handlr */
35 	void (*done) (struct scsi_cmnd *);	/* Mid-level done function */
36 
37 	/*
38 	 * A SCSI Command is assigned a nonzero serial_number before passed
39 	 * to the driver's queue command function.  The serial_number is
40 	 * cleared when scsi_done is entered indicating that the command
41 	 * has been completed.  It currently doesn't have much use other
42 	 * than printk's.  Some lldd's use this number for other purposes.
43 	 * It's almost certain that such usages are either incorrect or
44 	 * meaningless.  Please kill all usages other than printk's.  Also,
45 	 * as this number is always identical to ->pid, please convert
46 	 * printk's to use ->pid, so that we can kill this field.
47 	 */
48 	unsigned long serial_number;
49 	/*
50 	 * This is set to jiffies as it was when the command was first
51 	 * allocated.  It is used to time how long the command has
52 	 * been outstanding
53 	 */
54 	unsigned long jiffies_at_alloc;
55 
56 	int retries;
57 	int allowed;
58 	int timeout_per_command;
59 
60 	unsigned char cmd_len;
61 	enum dma_data_direction sc_data_direction;
62 
63 	/* These elements define the operation we are about to perform */
64 #define MAX_COMMAND_SIZE	16
65 	unsigned char cmnd[MAX_COMMAND_SIZE];
66 	unsigned request_bufflen;	/* Actual request size */
67 
68 	struct timer_list eh_timeout;	/* Used to time out the command. */
69 	void *request_buffer;		/* Actual requested buffer */
70 
71 	/* These elements define the operation we ultimately want to perform */
72 	unsigned short use_sg;	/* Number of pieces of scatter-gather */
73 	unsigned short sglist_len;	/* size of malloc'd scatter-gather list */
74 
75 	unsigned underflow;	/* Return error if less than
76 				   this amount is transferred */
77 
78 	unsigned transfersize;	/* How much we are guaranteed to
79 				   transfer with each SCSI transfer
80 				   (ie, between disconnect /
81 				   reconnects.   Probably == sector
82 				   size */
83 
84 	int resid;		/* Number of bytes requested to be
85 				   transferred less actual number
86 				   transferred (0 if not supported) */
87 
88 	struct request *request;	/* The command we are
89 				   	   working on */
90 
91 #define SCSI_SENSE_BUFFERSIZE 	96
92 	unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];
93 				/* obtained by REQUEST SENSE when
94 				 * CHECK CONDITION is received on original
95 				 * command (auto-sense) */
96 
97 	/* Low-level done function - can be used by low-level driver to point
98 	 *        to completion function.  Not used by mid/upper level code. */
99 	void (*scsi_done) (struct scsi_cmnd *);
100 
101 	/*
102 	 * The following fields can be written to by the host specific code.
103 	 * Everything else should be left alone.
104 	 */
105 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
106 
107 	unsigned char *host_scribble;	/* The host adapter is allowed to
108 					 * call scsi_malloc and get some memory
109 					 * and hang it here.  The host adapter
110 					 * is also expected to call scsi_free
111 					 * to release this memory.  (The memory
112 					 * obtained by scsi_malloc is guaranteed
113 					 * to be at an address < 16Mb). */
114 
115 	int result;		/* Status code from lower level driver */
116 
117 	unsigned char tag;	/* SCSI-II queued command tag */
118 	unsigned long pid;	/* Process ID, starts at 0. Unique per host. */
119 };
120 
121 /*
122  * These are the values that scsi_cmd->state can take.
123  */
124 #define SCSI_STATE_TIMEOUT         0x1000
125 #define SCSI_STATE_FINISHED        0x1001
126 #define SCSI_STATE_FAILED          0x1002
127 #define SCSI_STATE_QUEUED          0x1003
128 #define SCSI_STATE_UNUSED          0x1006
129 #define SCSI_STATE_DISCONNECTING   0x1008
130 #define SCSI_STATE_INITIALIZING    0x1009
131 #define SCSI_STATE_BHQUEUE         0x100a
132 #define SCSI_STATE_MLQUEUE         0x100b
133 
134 
135 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
136 extern void scsi_put_command(struct scsi_cmnd *);
137 extern void scsi_io_completion(struct scsi_cmnd *, unsigned int);
138 extern void scsi_finish_command(struct scsi_cmnd *cmd);
139 extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
140 
141 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
142 				 size_t *offset, size_t *len);
143 extern void scsi_kunmap_atomic_sg(void *virt);
144 
145 #endif /* _SCSI_SCSI_CMND_H */
146