xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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 
8 struct request;
9 struct scatterlist;
10 struct scsi_device;
11 struct scsi_request;
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 	int     sc_magic;
32 
33 	struct scsi_device *device;
34 	unsigned short state;
35 	unsigned short owner;
36 	struct scsi_request *sc_request;
37 
38 	struct list_head list;  /* scsi_cmnd participates in queue lists */
39 
40 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
41 	int eh_state;		/* Used for state tracking in error handlr */
42 	int eh_eflags;		/* Used by error handlr */
43 	void (*done) (struct scsi_cmnd *);	/* Mid-level done function */
44 
45 	/*
46 	 * A SCSI Command is assigned a nonzero serial_number when internal_cmnd
47 	 * passes it to the driver's queue command function.  The serial_number
48 	 * is cleared when scsi_done is entered indicating that the command has
49 	 * been completed.  If a timeout occurs, the serial number at the moment
50 	 * of timeout is copied into serial_number_at_timeout.  By subsequently
51 	 * comparing the serial_number and serial_number_at_timeout fields
52 	 * during abort or reset processing, we can detect whether the command
53 	 * has already completed.  This also detects cases where the command has
54 	 * completed and the SCSI Command structure has already being reused
55 	 * for another command, so that we can avoid incorrectly aborting or
56 	 * resetting the new command.
57 	 * The serial number is only unique per host.
58 	 */
59 	unsigned long serial_number;
60 	unsigned long serial_number_at_timeout;
61 
62 	int retries;
63 	int allowed;
64 	int timeout_per_command;
65 	int timeout_total;
66 	int timeout;
67 
68 	/*
69 	 * We handle the timeout differently if it happens when a reset,
70 	 * abort, etc are in process.
71 	 */
72 	unsigned volatile char internal_timeout;
73 
74 	unsigned char cmd_len;
75 	unsigned char old_cmd_len;
76 	enum dma_data_direction sc_data_direction;
77 	enum dma_data_direction sc_old_data_direction;
78 
79 	/* These elements define the operation we are about to perform */
80 #define MAX_COMMAND_SIZE	16
81 	unsigned char cmnd[MAX_COMMAND_SIZE];
82 	unsigned request_bufflen;	/* Actual request size */
83 
84 	struct timer_list eh_timeout;	/* Used to time out the command. */
85 	void *request_buffer;		/* Actual requested buffer */
86 
87 	/* These elements define the operation we ultimately want to perform */
88 	unsigned char data_cmnd[MAX_COMMAND_SIZE];
89 	unsigned short old_use_sg;	/* We save  use_sg here when requesting
90 					 * sense info */
91 	unsigned short use_sg;	/* Number of pieces of scatter-gather */
92 	unsigned short sglist_len;	/* size of malloc'd scatter-gather list */
93 	unsigned short abort_reason;	/* If the mid-level code requests an
94 					 * abort, this is the reason. */
95 	unsigned bufflen;	/* Size of data buffer */
96 	void *buffer;		/* Data buffer */
97 
98 	unsigned underflow;	/* Return error if less than
99 				   this amount is transferred */
100 	unsigned old_underflow;	/* save underflow here when reusing the
101 				 * command for error handling */
102 
103 	unsigned transfersize;	/* How much we are guaranteed to
104 				   transfer with each SCSI transfer
105 				   (ie, between disconnect /
106 				   reconnects.   Probably == sector
107 				   size */
108 
109 	int resid;		/* Number of bytes requested to be
110 				   transferred less actual number
111 				   transferred (0 if not supported) */
112 
113 	struct request *request;	/* The command we are
114 				   	   working on */
115 
116 #define SCSI_SENSE_BUFFERSIZE 	96
117 	unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];		/* obtained by REQUEST SENSE
118 						 * when CHECK CONDITION is
119 						 * received on original command
120 						 * (auto-sense) */
121 
122 	/* Low-level done function - can be used by low-level driver to point
123 	 *        to completion function.  Not used by mid/upper level code. */
124 	void (*scsi_done) (struct scsi_cmnd *);
125 
126 	/*
127 	 * The following fields can be written to by the host specific code.
128 	 * Everything else should be left alone.
129 	 */
130 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
131 
132 	unsigned char *host_scribble;	/* The host adapter is allowed to
133 					   * call scsi_malloc and get some memory
134 					   * and hang it here.     The host adapter
135 					   * is also expected to call scsi_free
136 					   * to release this memory.  (The memory
137 					   * obtained by scsi_malloc is guaranteed
138 					   * to be at an address < 16Mb). */
139 
140 	int result;		/* Status code from lower level driver */
141 
142 	unsigned char tag;	/* SCSI-II queued command tag */
143 	unsigned long pid;	/* Process ID, starts at 0. Unique per host. */
144 };
145 
146 /*
147  * These are the values that scsi_cmd->state can take.
148  */
149 #define SCSI_STATE_TIMEOUT         0x1000
150 #define SCSI_STATE_FINISHED        0x1001
151 #define SCSI_STATE_FAILED          0x1002
152 #define SCSI_STATE_QUEUED          0x1003
153 #define SCSI_STATE_UNUSED          0x1006
154 #define SCSI_STATE_DISCONNECTING   0x1008
155 #define SCSI_STATE_INITIALIZING    0x1009
156 #define SCSI_STATE_BHQUEUE         0x100a
157 #define SCSI_STATE_MLQUEUE         0x100b
158 
159 
160 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, int);
161 extern void scsi_put_command(struct scsi_cmnd *);
162 extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
163 extern void scsi_finish_command(struct scsi_cmnd *cmd);
164 
165 #endif /* _SCSI_SCSI_CMND_H */
166