xref: /kernel/linux/linux-5.10/include/scsi/sg.h (revision 8c2ecf20)
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _SCSI_GENERIC_H
3#define _SCSI_GENERIC_H
4
5#include <linux/compiler.h>
6
7/*
8 * History:
9 *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com), to allow user
10 *   process control of SCSI devices.
11 *  Development Sponsored by Killy Corp. NY NY
12 *
13 * Original driver (sg.h):
14 *       Copyright (C) 1992 Lawrence Foard
15 * Version 2 and 3 extensions to driver:
16 *	Copyright (C) 1998 - 2014 Douglas Gilbert
17 *
18 *  Version: 3.5.36 (20140603)
19 *  This version is for 2.6 and 3 series kernels.
20 *
21 * Documentation
22 * =============
23 * A web site for the SG device driver can be found at:
24 *	http://sg.danny.cz/sg  [alternatively check the MAINTAINERS file]
25 * The documentation for the sg version 3 driver can be found at:
26 *	http://sg.danny.cz/sg/p/sg_v3_ho.html
27 * Also see: <kernel_source>/Documentation/scsi/scsi-generic.rst
28 *
29 * For utility and test programs see: http://sg.danny.cz/sg/sg3_utils.html
30 */
31
32#ifdef __KERNEL__
33extern int sg_big_buff; /* for sysctl */
34#endif
35
36
37typedef struct sg_iovec /* same structure as used by readv() Linux system */
38{                       /* call. It defines one scatter-gather element. */
39    void __user *iov_base;      /* Starting address  */
40    size_t iov_len;             /* Length in bytes  */
41} sg_iovec_t;
42
43
44typedef struct sg_io_hdr
45{
46    int interface_id;           /* [i] 'S' for SCSI generic (required) */
47    int dxfer_direction;        /* [i] data transfer direction  */
48    unsigned char cmd_len;      /* [i] SCSI command length */
49    unsigned char mx_sb_len;    /* [i] max length to write to sbp */
50    unsigned short iovec_count; /* [i] 0 implies no scatter gather */
51    unsigned int dxfer_len;     /* [i] byte count of data transfer */
52    void __user *dxferp;	/* [i], [*io] points to data transfer memory
53					      or scatter gather list */
54    unsigned char __user *cmdp; /* [i], [*i] points to command to perform */
55    void __user *sbp;		/* [i], [*o] points to sense_buffer memory */
56    unsigned int timeout;       /* [i] MAX_UINT->no timeout (unit: millisec) */
57    unsigned int flags;         /* [i] 0 -> default, see SG_FLAG... */
58    int pack_id;                /* [i->o] unused internally (normally) */
59    void __user * usr_ptr;      /* [i->o] unused internally */
60    unsigned char status;       /* [o] scsi status */
61    unsigned char masked_status;/* [o] shifted, masked scsi status */
62    unsigned char msg_status;   /* [o] messaging level data (optional) */
63    unsigned char sb_len_wr;    /* [o] byte count actually written to sbp */
64    unsigned short host_status; /* [o] errors from host adapter */
65    unsigned short driver_status;/* [o] errors from software driver */
66    int resid;                  /* [o] dxfer_len - actual_transferred */
67    unsigned int duration;      /* [o] time taken by cmd (unit: millisec) */
68    unsigned int info;          /* [o] auxiliary information */
69} sg_io_hdr_t;  /* 64 bytes long (on i386) */
70
71#if defined(__KERNEL__)
72#include <linux/compat.h>
73
74struct compat_sg_io_hdr {
75	compat_int_t interface_id;	/* [i] 'S' for SCSI generic (required) */
76	compat_int_t dxfer_direction;	/* [i] data transfer direction  */
77	unsigned char cmd_len;		/* [i] SCSI command length ( <= 16 bytes) */
78	unsigned char mx_sb_len;	/* [i] max length to write to sbp */
79	unsigned short iovec_count;	/* [i] 0 implies no scatter gather */
80	compat_uint_t dxfer_len;	/* [i] byte count of data transfer */
81	compat_uint_t dxferp;		/* [i], [*io] points to data transfer memory
82						or scatter gather list */
83	compat_uptr_t cmdp;		/* [i], [*i] points to command to perform */
84	compat_uptr_t sbp;		/* [i], [*o] points to sense_buffer memory */
85	compat_uint_t timeout;		/* [i] MAX_UINT->no timeout (unit: millisec) */
86	compat_uint_t flags;		/* [i] 0 -> default, see SG_FLAG... */
87	compat_int_t pack_id;		/* [i->o] unused internally (normally) */
88	compat_uptr_t usr_ptr;		/* [i->o] unused internally */
89	unsigned char status;		/* [o] scsi status */
90	unsigned char masked_status;	/* [o] shifted, masked scsi status */
91	unsigned char msg_status;	/* [o] messaging level data (optional) */
92	unsigned char sb_len_wr;	/* [o] byte count actually written to sbp */
93	unsigned short host_status;	/* [o] errors from host adapter */
94	unsigned short driver_status;	/* [o] errors from software driver */
95	compat_int_t resid;		/* [o] dxfer_len - actual_transferred */
96	compat_uint_t duration;		/* [o] time taken by cmd (unit: millisec) */
97	compat_uint_t info;		/* [o] auxiliary information */
98};
99#endif
100
101#define SG_INTERFACE_ID_ORIG 'S'
102
103/* Use negative values to flag difference from original sg_header structure */
104#define SG_DXFER_NONE (-1)      /* e.g. a SCSI Test Unit Ready command */
105#define SG_DXFER_TO_DEV (-2)    /* e.g. a SCSI WRITE command */
106#define SG_DXFER_FROM_DEV (-3)  /* e.g. a SCSI READ command */
107#define SG_DXFER_TO_FROM_DEV (-4) /* treated like SG_DXFER_FROM_DEV with the
108				   additional property than during indirect
109				   IO the user buffer is copied into the
110				   kernel buffers before the transfer */
111#define SG_DXFER_UNKNOWN (-5)   /* Unknown data direction */
112
113/* following flag values can be "or"-ed together */
114#define SG_FLAG_DIRECT_IO 1     /* default is indirect IO */
115#define SG_FLAG_UNUSED_LUN_INHIBIT 2   /* default is overwrite lun in SCSI */
116				/* command block (when <= SCSI_2) */
117#define SG_FLAG_MMAP_IO 4       /* request memory mapped IO */
118#define SG_FLAG_NO_DXFER 0x10000 /* no transfer of kernel buffers to/from */
119				/* user space (debug indirect IO) */
120/* defaults:: for sg driver: Q_AT_HEAD; for block layer: Q_AT_TAIL */
121#define SG_FLAG_Q_AT_TAIL 0x10
122#define SG_FLAG_Q_AT_HEAD 0x20
123
124/* following 'info' values are "or"-ed together */
125#define SG_INFO_OK_MASK 0x1
126#define SG_INFO_OK 0x0          /* no sense, host nor driver "noise" */
127#define SG_INFO_CHECK 0x1       /* something abnormal happened */
128
129#define SG_INFO_DIRECT_IO_MASK 0x6
130#define SG_INFO_INDIRECT_IO 0x0 /* data xfer via kernel buffers (or no xfer) */
131#define SG_INFO_DIRECT_IO 0x2   /* direct IO requested and performed */
132#define SG_INFO_MIXED_IO 0x4    /* part direct, part indirect IO */
133
134
135typedef struct sg_scsi_id { /* used by SG_GET_SCSI_ID ioctl() */
136    int host_no;        /* as in "scsi<n>" where 'n' is one of 0, 1, 2 etc */
137    int channel;
138    int scsi_id;        /* scsi id of target device */
139    int lun;
140    int scsi_type;      /* TYPE_... defined in scsi/scsi.h */
141    short h_cmd_per_lun;/* host (adapter) maximum commands per lun */
142    short d_queue_depth;/* device (or adapter) maximum queue length */
143    int unused[2];      /* probably find a good use, set 0 for now */
144} sg_scsi_id_t; /* 32 bytes long on i386 */
145
146typedef struct sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
147    char req_state;     /* 0 -> not used, 1 -> written, 2 -> ready to read */
148    char orphan;        /* 0 -> normal request, 1 -> from interruped SG_IO */
149    char sg_io_owned;   /* 0 -> complete with read(), 1 -> owned by SG_IO */
150    char problem;       /* 0 -> no problem detected, 1 -> error to report */
151    int pack_id;        /* pack_id associated with request */
152    void __user *usr_ptr;     /* user provided pointer (in new interface) */
153    unsigned int duration; /* millisecs elapsed since written (req_state==1)
154			      or request duration (req_state==2) */
155    int unused;
156} sg_req_info_t; /* 20 bytes long on i386 */
157
158
159/* IOCTLs: Those ioctls that are relevant to the SG 3.x drivers follow.
160 [Those that only apply to the SG 2.x drivers are at the end of the file.]
161 (_GET_s yield result via 'int *' 3rd argument unless otherwise indicated) */
162
163#define SG_EMULATED_HOST 0x2203 /* true for emulated host adapter (ATAPI) */
164
165/* Used to configure SCSI command transformation layer for ATAPI devices */
166/* Only supported by the ide-scsi driver */
167#define SG_SET_TRANSFORM 0x2204 /* N.B. 3rd arg is not pointer but value: */
168		      /* 3rd arg = 0 to disable transform, 1 to enable it */
169#define SG_GET_TRANSFORM 0x2205
170
171#define SG_SET_RESERVED_SIZE 0x2275  /* request a new reserved buffer size */
172#define SG_GET_RESERVED_SIZE 0x2272  /* actual size of reserved buffer */
173
174/* The following ioctl has a 'sg_scsi_id_t *' object as its 3rd argument. */
175#define SG_GET_SCSI_ID 0x2276   /* Yields fd's bus, chan, dev, lun + type */
176/* SCSI id information can also be obtained from SCSI_IOCTL_GET_IDLUN */
177
178/* Override host setting and always DMA using low memory ( <16MB on i386) */
179#define SG_SET_FORCE_LOW_DMA 0x2279  /* 0-> use adapter setting, 1-> force */
180#define SG_GET_LOW_DMA 0x227a   /* 0-> use all ram for dma; 1-> low dma ram */
181
182/* When SG_SET_FORCE_PACK_ID set to 1, pack_id is input to read() which
183   tries to fetch a packet with a matching pack_id, waits, or returns EAGAIN.
184   If pack_id is -1 then read oldest waiting. When ...FORCE_PACK_ID set to 0
185   then pack_id ignored by read() and oldest readable fetched. */
186#define SG_SET_FORCE_PACK_ID 0x227b
187#define SG_GET_PACK_ID 0x227c /* Yields oldest readable pack_id (or -1) */
188
189#define SG_GET_NUM_WAITING 0x227d /* Number of commands awaiting read() */
190
191/* Yields max scatter gather tablesize allowed by current host adapter */
192#define SG_GET_SG_TABLESIZE 0x227F  /* 0 implies can't do scatter gather */
193
194#define SG_GET_VERSION_NUM 0x2282 /* Example: version 2.1.34 yields 20134 */
195
196/* Returns -EBUSY if occupied. 3rd argument pointer to int (see next) */
197#define SG_SCSI_RESET 0x2284
198/* Associated values that can be given to SG_SCSI_RESET follow.
199 * SG_SCSI_RESET_NO_ESCALATE may be OR-ed to the _DEVICE, _TARGET, _BUS
200 * or _HOST reset value so only that action is attempted. */
201#define		SG_SCSI_RESET_NOTHING	0
202#define		SG_SCSI_RESET_DEVICE	1
203#define		SG_SCSI_RESET_BUS	2
204#define		SG_SCSI_RESET_HOST	3
205#define		SG_SCSI_RESET_TARGET	4
206#define		SG_SCSI_RESET_NO_ESCALATE	0x100
207
208/* synchronous SCSI command ioctl, (only in version 3 interface) */
209#define SG_IO 0x2285   /* similar effect as write() followed by read() */
210
211#define SG_GET_REQUEST_TABLE 0x2286   /* yields table of active requests */
212
213/* How to treat EINTR during SG_IO ioctl(), only in SG 3.x series */
214#define SG_SET_KEEP_ORPHAN 0x2287 /* 1 -> hold for read(), 0 -> drop (def) */
215#define SG_GET_KEEP_ORPHAN 0x2288
216
217/* yields scsi midlevel's access_count for this SCSI device */
218#define SG_GET_ACCESS_COUNT 0x2289
219
220
221#define SG_SCATTER_SZ (8 * 4096)
222/* Largest size (in bytes) a single scatter-gather list element can have.
223   The value used by the driver is 'max(SG_SCATTER_SZ, PAGE_SIZE)'.
224   This value should be a power of 2 (and may be rounded up internally).
225   If scatter-gather is not supported by adapter then this value is the
226   largest data block that can be read/written by a single scsi command. */
227
228#define SG_DEFAULT_RETRIES 0
229
230/* Defaults, commented if they differ from original sg driver */
231#define SG_DEF_FORCE_PACK_ID 0
232#define SG_DEF_KEEP_ORPHAN 0
233#define SG_DEF_RESERVED_SIZE SG_SCATTER_SZ /* load time option */
234
235/* maximum outstanding requests, write() yields EDOM if exceeded */
236#define SG_MAX_QUEUE 16
237
238#define SG_BIG_BUFF SG_DEF_RESERVED_SIZE    /* for backward compatibility */
239
240/* Alternate style type names, "..._t" variants preferred */
241typedef struct sg_io_hdr Sg_io_hdr;
242typedef struct sg_io_vec Sg_io_vec;
243typedef struct sg_scsi_id Sg_scsi_id;
244typedef struct sg_req_info Sg_req_info;
245
246
247/* vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv */
248/*   The older SG interface based on the 'sg_header' structure follows.   */
249/* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
250
251#define SG_MAX_SENSE 16   /* this only applies to the sg_header interface */
252
253struct sg_header
254{
255    int pack_len;    /* [o] reply_len (ie useless), ignored as input */
256    int reply_len;   /* [i] max length of expected reply (inc. sg_header) */
257    int pack_id;     /* [io] id number of packet (use ints >= 0) */
258    int result;      /* [o] 0==ok, else (+ve) Unix errno (best ignored) */
259    unsigned int twelve_byte:1;
260	/* [i] Force 12 byte command length for group 6 & 7 commands  */
261    unsigned int target_status:5;   /* [o] scsi status from target */
262    unsigned int host_status:8;     /* [o] host status (see "DID" codes) */
263    unsigned int driver_status:8;   /* [o] driver status+suggestion */
264    unsigned int other_flags:10;    /* unused */
265    unsigned char sense_buffer[SG_MAX_SENSE]; /* [o] Output in 3 cases:
266	   when target_status is CHECK_CONDITION or
267	   when target_status is COMMAND_TERMINATED or
268	   when (driver_status & DRIVER_SENSE) is true. */
269};      /* This structure is 36 bytes long on i386 */
270
271
272/* IOCTLs: The following are not required (or ignored) when the sg_io_hdr_t
273	   interface is used. They are kept for backward compatibility with
274	   the original and version 2 drivers. */
275
276#define SG_SET_TIMEOUT 0x2201  /* unit: jiffies (10ms on i386) */
277#define SG_GET_TIMEOUT 0x2202  /* yield timeout as _return_ value */
278
279/* Get/set command queuing state per fd (default is SG_DEF_COMMAND_Q.
280   Each time a sg_io_hdr_t object is seen on this file descriptor, this
281   command queuing flag is set on (overriding the previous setting). */
282#define SG_GET_COMMAND_Q 0x2270   /* Yields 0 (queuing off) or 1 (on) */
283#define SG_SET_COMMAND_Q 0x2271   /* Change queuing state with 0 or 1 */
284
285/* Turn on/off error sense trace (1 and 0 respectively, default is off).
286   Try using: "# cat /proc/scsi/sg/debug" instead in the v3 driver */
287#define SG_SET_DEBUG 0x227e    /* 0 -> turn off debug */
288
289#define SG_NEXT_CMD_LEN 0x2283  /* override SCSI command length with given
290		   number on the next write() on this file descriptor */
291
292
293/* Defaults, commented if they differ from original sg driver */
294#ifdef __KERNEL__
295#define SG_DEFAULT_TIMEOUT_USER	(60*USER_HZ) /* HZ == 'jiffies in 1 second' */
296#else
297#define SG_DEFAULT_TIMEOUT	(60*HZ)	     /* HZ == 'jiffies in 1 second' */
298#endif
299
300#define SG_DEF_COMMAND_Q 0     /* command queuing is always on when
301				  the new interface is used */
302#define SG_DEF_UNDERRUN_FLAG 0
303
304#endif
305