1 /* Copyright (C) 1997-2022 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <https://www.gnu.org/licenses/>.  */
17 
18 /*
19    History:
20     Started: Aug 9 by Lawrence Foard (entropy@world.std.com), to allow user
21      process control of SCSI devices.
22     Development Sponsored by Killy Corp. NY NY
23 */
24 
25 #ifndef _SCSI_SG_H
26 #define _SCSI_SG_H	1
27 
28 #include <features.h>
29 #define __need_size_t
30 #include <stddef.h>
31 
32 
33 /* New interface introduced in the 3.x SG drivers follows */
34 
35 /* Same structure as used by readv() Linux system call. It defines one
36    scatter-gather element. */
37 typedef struct sg_iovec
38 {
39   void * iov_base;            /* Starting address  */
40   size_t iov_len;             /* Length in bytes  */
41 } sg_iovec_t;
42 
43 
44 typedef 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 ( <= 16 bytes) */
49   unsigned char mx_sb_len;    /* [i] max length to write to sbp */
50   unsigned short int iovec_count; /* [i] 0 implies no scatter gather */
51   unsigned int dxfer_len;     /* [i] byte count of data transfer */
52   void * dxferp;              /* [i], [*io] points to data transfer memory
53 				 or scatter gather list */
54   unsigned char * cmdp;       /* [i], [*i] points to command to perform */
55   unsigned char * 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 * 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 int host_status; /* [o] errors from host adapter */
65   unsigned short int 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;
70 
71 
72 /* Use negative values to flag difference from original sg_header structure.  */
73 #define SG_DXFER_NONE -1        /* e.g. a SCSI Test Unit Ready command */
74 #define SG_DXFER_TO_DEV -2      /* e.g. a SCSI WRITE command */
75 #define SG_DXFER_FROM_DEV -3    /* e.g. a SCSI READ command */
76 #define SG_DXFER_TO_FROM_DEV -4 /* treated like SG_DXFER_FROM_DEV with the
77 				   additional property than during indirect
78 				   IO the user buffer is copied into the
79 				   kernel buffers before the transfer */
80 
81 
82 /* following flag values can be "or"-ed together */
83 #define SG_FLAG_DIRECT_IO 1     /* default is indirect IO */
84 #define SG_FLAG_LUN_INHIBIT 2   /* default is to put device's lun into */
85 				/* the 2nd byte of SCSI command */
86 #define SG_FLAG_NO_DXFER 0x10000 /* no transfer of kernel buffers to/from */
87 				/* user space (debug indirect IO) */
88 
89 /* The following 'info' values are "or"-ed together.  */
90 #define SG_INFO_OK_MASK	0x1
91 #define SG_INFO_OK	0x0	/* no sense, host nor driver "noise" */
92 #define SG_INFO_CHECK	0x1     /* something abnormal happened */
93 
94 #define SG_INFO_DIRECT_IO_MASK	0x6
95 #define SG_INFO_INDIRECT_IO 	0x0	/* data xfer via kernel buffers (or no xfer) */
96 #define SG_INFO_DIRECT_IO 	0x2	/* direct IO requested and performed */
97 #define SG_INFO_MIXED_IO 	0x4	/* part direct, part indirect IO */
98 
99 
100 /* Request information about a specific SG device, used by
101    SG_GET_SCSI_ID ioctl ().  */
102 struct sg_scsi_id {
103   /* Host number as in "scsi<n>" where 'n' is one of 0, 1, 2 etc.  */
104   int host_no;
105   int channel;
106   /* SCSI id of target device.  */
107   int scsi_id;
108   int lun;
109   /* TYPE_... defined in <scsi/scsi.h>.  */
110   int scsi_type;
111   /* Host (adapter) maximum commands per lun.  */
112   short int h_cmd_per_lun;
113   /* Device (or adapter) maximum queue length.  */
114   short int d_queue_depth;
115   /* Unused, set to 0 for now.  */
116   int unused[2];
117 };
118 
119 /* Used by SG_GET_REQUEST_TABLE ioctl().  */
120 typedef struct sg_req_info {
121     char req_state;     /* 0 -> not used, 1 -> written, 2 -> ready to read */
122     char orphan;        /* 0 -> normal request, 1 -> from interruped SG_IO */
123     char sg_io_owned;   /* 0 -> complete with read(), 1 -> owned by SG_IO */
124     char problem;       /* 0 -> no problem detected, 1 -> error to report */
125     int pack_id;        /* pack_id associated with request */
126     void * usr_ptr;     /* user provided pointer (in new interface) */
127     unsigned int duration; /* millisecs elapsed since written (req_state==1)
128 			      or request duration (req_state==2) */
129     int unused;
130 } sg_req_info_t;
131 
132 
133 /* IOCTLs: Those ioctls that are relevant to the SG 3.x drivers follow.
134  [Those that only apply to the SG 2.x drivers are at the end of the file.]
135  (_GET_s yield result via 'int *' 3rd argument unless otherwise indicated) */
136 
137 #define SG_EMULATED_HOST 0x2203 /* true for emulated host adapter (ATAPI) */
138 
139 /* Used to configure SCSI command transformation layer for ATAPI devices */
140 /* Only supported by the ide-scsi driver */
141 #define SG_SET_TRANSFORM 0x2204 /* N.B. 3rd arg is not pointer but value: */
142 		      /* 3rd arg = 0 to disable transform, 1 to enable it */
143 #define SG_GET_TRANSFORM 0x2205
144 
145 #define SG_SET_RESERVED_SIZE 0x2275  /* request a new reserved buffer size */
146 #define SG_GET_RESERVED_SIZE 0x2272  /* actual size of reserved buffer */
147 
148 /* The following ioctl has a 'sg_scsi_id_t *' object as its 3rd argument. */
149 #define SG_GET_SCSI_ID 0x2276   /* Yields fd's bus, chan, dev, lun + type */
150 /* SCSI id information can also be obtained from SCSI_IOCTL_GET_IDLUN */
151 
152 /* Override host setting and always DMA using low memory ( <16MB on i386) */
153 #define SG_SET_FORCE_LOW_DMA 0x2279  /* 0-> use adapter setting, 1-> force */
154 #define SG_GET_LOW_DMA 0x227a   /* 0-> use all ram for dma; 1-> low dma ram */
155 
156 /* When SG_SET_FORCE_PACK_ID set to 1, pack_id is input to read() which
157    tries to fetch a packet with a matching pack_id, waits, or returns EAGAIN.
158    If pack_id is -1 then read oldest waiting. When ...FORCE_PACK_ID set to 0
159    then pack_id ignored by read() and oldest readable fetched. */
160 #define SG_SET_FORCE_PACK_ID 0x227b
161 #define SG_GET_PACK_ID 0x227c /* Yields oldest readable pack_id (or -1) */
162 
163 #define SG_GET_NUM_WAITING 0x227d /* Number of commands awaiting read() */
164 
165 /* Yields max scatter gather tablesize allowed by current host adapter */
166 #define SG_GET_SG_TABLESIZE 0x227F  /* 0 implies can't do scatter gather */
167 
168 #define SG_GET_VERSION_NUM 0x2282 /* Example: version 2.1.34 yields 20134 */
169 
170 /* Returns -EBUSY if occupied. 3rd argument pointer to int (see next) */
171 #define SG_SCSI_RESET 0x2284
172 /* Associated values that can be given to SG_SCSI_RESET follow */
173 #define SG_SCSI_RESET_NOTHING	0
174 #define SG_SCSI_RESET_DEVICE	1
175 #define SG_SCSI_RESET_BUS	2
176 #define SG_SCSI_RESET_HOST	3
177 
178 /* synchronous SCSI command ioctl, (only in version 3 interface) */
179 #define SG_IO 0x2285   /* similar effect as write() followed by read() */
180 
181 #define SG_GET_REQUEST_TABLE 0x2286   /* yields table of active requests */
182 
183 /* How to treat EINTR during SG_IO ioctl(), only in SG 3.x series */
184 #define SG_SET_KEEP_ORPHAN 0x2287 /* 1 -> hold for read(), 0 -> drop (def) */
185 #define SG_GET_KEEP_ORPHAN 0x2288
186 
187 
188 #define SG_SCATTER_SZ (8 * 4096)  /* PAGE_SIZE not available to user */
189 /* Largest size (in bytes) a single scatter-gather list element can have.
190    The value must be a power of 2 and <= (PAGE_SIZE * 32) [131072 bytes on
191    i386]. The minimum value is PAGE_SIZE. If scatter-gather not supported
192    by adapter then this value is the largest data block that can be
193    read/written by a single scsi command. The user can find the value of
194    PAGE_SIZE by calling getpagesize() defined in unistd.h . */
195 
196 #define SG_DEFAULT_RETRIES 1
197 
198 /* Defaults, commented if they differ from original sg driver */
199 #define SG_DEF_FORCE_LOW_DMA 0  /* was 1 -> memory below 16MB on i386 */
200 #define SG_DEF_FORCE_PACK_ID 0
201 #define SG_DEF_KEEP_ORPHAN 0
202 #define SG_DEF_RESERVED_SIZE SG_SCATTER_SZ /* load time option */
203 
204 /* maximum outstanding requests, write() yields EDOM if exceeded */
205 #define SG_MAX_QUEUE 16
206 
207 #define SG_BIG_BUFF SG_DEF_RESERVED_SIZE    /* for backward compatibility */
208 
209 /* Alternate style type names, "..._t" variants preferred */
210 typedef struct sg_io_hdr Sg_io_hdr;
211 typedef struct sg_io_vec Sg_io_vec;
212 typedef struct sg_scsi_id Sg_scsi_id;
213 typedef struct sg_req_info Sg_req_info;
214 
215 
216 /* vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv */
217 /*   The older SG interface based on the 'sg_header' structure follows.   */
218 /* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
219 
220 #define SG_MAX_SENSE 16   /* this only applies to the sg_header interface */
221 
222 struct sg_header
223  {
224    /* Length of incoming packet (including header).  */
225    int pack_len;
226    /* Maximal length of expected reply.  */
227    int reply_len;
228    /* Id number of packet.  */
229    int pack_id;
230    /* 0==ok, otherwise error number.  */
231    int result;
232    /* Force 12 byte command length for group 6 & 7 commands.  */
233    unsigned int twelve_byte:1;
234    /* SCSI status from target.  */
235    unsigned int target_status:5;
236    /* Host status (see "DID" codes).  */
237    unsigned int host_status:8;
238    /* Driver status+suggestion.  */
239    unsigned int driver_status:8;
240    /* Unused.  */
241    unsigned int other_flags:10;
242    /* Output in 3 cases:
243       when target_status is CHECK_CONDITION or
244       when target_status is COMMAND_TERMINATED or
245       when (driver_status & DRIVER_SENSE) is true.  */
246    unsigned char sense_buffer[SG_MAX_SENSE];
247  };
248 
249 
250 /* IOCTLs: The following are not required (or ignored) when the sg_io_hdr_t
251 	   interface is used. They are kept for backward compatibility with
252 	   the original and version 2 drivers. */
253 
254 #define SG_SET_TIMEOUT		0x2201	/* Set timeout; *(int *)arg==timeout.  */
255 #define SG_GET_TIMEOUT		0x2202	/* Get timeout; return timeout.  */
256 
257 /* Get/set command queuing state per fd (default is SG_DEF_COMMAND_Q). */
258 #define SG_GET_COMMAND_Q	0x2270	/* Yields 0 (queuing off) or 1 (on).  */
259 #define SG_SET_COMMAND_Q 	0x2271	/* Change queuing state with 0 or 1.  */
260 
261 /* Turn on error sense trace (1..8), dump this device to log/console (9)
262    or dump all sg device states ( >9 ) to log/console.  */
263 #define SG_SET_DEBUG		0x227e	/* 0 -> turn off debug */
264 
265 #define SG_NEXT_CMD_LEN		0x2283	/* Override SCSI command length with given
266 					   number on the next write() on this file
267 					   descriptor.  */
268 
269 /* Defaults, commented if they differ from original sg driver */
270 #define SG_DEFAULT_TIMEOUT (60*HZ) /* HZ == 'jiffies in 1 second' */
271 #define SG_DEF_COMMAND_Q 0     /* command queuing is always on when
272 				  the new interface is used */
273 #define SG_DEF_UNDERRUN_FLAG 0
274 
275 
276 #endif	/* scsi/sg.h */
277