xref: /openbmc/linux/drivers/scsi/st.h (revision cf21eb6a)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #ifndef _ST_H
4 #define _ST_H
5 
6 #include <linux/completion.h>
7 #include <linux/mutex.h>
8 #include <linux/kref.h>
9 #include <scsi/scsi_cmnd.h>
10 
11 /* Descriptor for analyzed sense data */
12 struct st_cmdstatus {
13 	int midlevel_result;
14 	struct scsi_sense_hdr sense_hdr;
15 	int have_sense;
16 	int residual;
17 	u64 uremainder64;
18 	u8 flags;
19 	u8 remainder_valid;
20 	u8 fixed_format;
21 	u8 deferred;
22 };
23 
24 struct scsi_tape;
25 
26 /* scsi tape command */
27 struct st_request {
28 	unsigned char cmd[MAX_COMMAND_SIZE];
29 	unsigned char sense[SCSI_SENSE_BUFFERSIZE];
30 	int result;
31 	struct scsi_tape *stp;
32 	struct completion *waiting;
33 	struct bio *bio;
34 };
35 
36 /* The tape buffer descriptor. */
37 struct st_buffer {
38 	unsigned char cleared;  /* internal buffer cleared after open? */
39 	unsigned short do_dio;  /* direct i/o set up? */
40 	int buffer_size;
41 	int buffer_blocks;
42 	int buffer_bytes;
43 	int read_pointer;
44 	int writing;
45 	int syscall_result;
46 	struct st_request *last_SRpnt;
47 	struct st_cmdstatus cmdstat;
48 	struct page **reserved_pages;
49 	int reserved_page_order;
50 	struct page **mapped_pages;
51 	struct rq_map_data map_data;
52 	unsigned char *b_data;
53 	unsigned short use_sg;	/* zero or max number of s/g segments for this adapter */
54 	unsigned short sg_segs;		/* number of segments in s/g list */
55 	unsigned short frp_segs;	/* number of buffer segments */
56 };
57 
58 /* The tape mode definition */
59 struct st_modedef {
60 	unsigned char defined;
61 	unsigned char sysv;	/* SYS V semantics? */
62 	unsigned char do_async_writes;
63 	unsigned char do_buffer_writes;
64 	unsigned char do_read_ahead;
65 	unsigned char defaults_for_writes;
66 	unsigned char default_compression;	/* 0 = don't touch, etc */
67 	short default_density;	/* Forced density, -1 = no value */
68 	int default_blksize;	/* Forced blocksize, -1 = no value */
69 	struct scsi_tape *tape;
70 	struct device *devs[2];  /* Auto-rewind and non-rewind devices */
71 	struct cdev *cdevs[2];  /* Auto-rewind and non-rewind devices */
72 };
73 
74 /* Number of modes can be changed by changing ST_NBR_MODE_BITS. The maximum
75    number of modes is 16 (ST_NBR_MODE_BITS 4) */
76 #define ST_NBR_MODE_BITS 2
77 #define ST_NBR_MODES (1 << ST_NBR_MODE_BITS)
78 #define ST_MODE_SHIFT (7 - ST_NBR_MODE_BITS)
79 #define ST_MODE_MASK ((ST_NBR_MODES - 1) << ST_MODE_SHIFT)
80 
81 #define ST_MAX_TAPES (1 << (20 - (ST_NBR_MODE_BITS + 1)))
82 #define ST_MAX_TAPE_ENTRIES  (ST_MAX_TAPES << (ST_NBR_MODE_BITS + 1))
83 
84 /* The status related to each partition */
85 struct st_partstat {
86 	unsigned char rw;
87 	unsigned char eof;
88 	unsigned char at_sm;
89 	unsigned char last_block_valid;
90 	u32 last_block_visited;
91 	int drv_block;		/* The block where the drive head is */
92 	int drv_file;
93 };
94 
95 /* Tape statistics */
96 struct scsi_tape_stats {
97 	atomic64_t read_byte_cnt;  /* bytes read */
98 	atomic64_t write_byte_cnt; /* bytes written */
99 	atomic64_t in_flight;      /* Number of I/Os in flight */
100 	atomic64_t read_cnt;       /* Count of read requests */
101 	atomic64_t write_cnt;      /* Count of write requests */
102 	atomic64_t other_cnt;      /* Count of other requests either
103 				    * implicit or from user space
104 				    * ioctl. */
105 	atomic64_t resid_cnt;      /* Count of resid_len > 0 */
106 	atomic64_t tot_read_time;  /* ktime spent completing reads */
107 	atomic64_t tot_write_time; /* ktime spent completing writes */
108 	atomic64_t tot_io_time;    /* ktime spent doing any I/O */
109 	ktime_t read_time;         /* holds ktime request was queued */
110 	ktime_t write_time;        /* holds ktime request was queued */
111 	ktime_t other_time;        /* holds ktime request was queued */
112 	atomic_t last_read_size;   /* Number of bytes issued for last read */
113 	atomic_t last_write_size;  /* Number of bytes issued for last write */
114 };
115 
116 #define ST_NBR_PARTITIONS 4
117 
118 /* The tape drive descriptor */
119 struct scsi_tape {
120 	struct scsi_device *device;
121 	struct mutex lock;	/* For serialization */
122 	struct completion wait;	/* For SCSI commands */
123 	struct st_buffer *buffer;
124 	int index;
125 
126 	/* Drive characteristics */
127 	unsigned char omit_blklims;
128 	unsigned char do_auto_lock;
129 	unsigned char can_bsr;
130 	unsigned char can_partitions;
131 	unsigned char two_fm;
132 	unsigned char fast_mteom;
133 	unsigned char immediate;
134 	unsigned char scsi2_logical;
135 	unsigned char default_drvbuffer;	/* 0xff = don't touch, value 3 bits */
136 	unsigned char cln_mode;			/* 0 = none, otherwise sense byte nbr */
137 	unsigned char cln_sense_value;
138 	unsigned char cln_sense_mask;
139 	unsigned char use_pf;			/* Set Page Format bit in all mode selects? */
140 	unsigned char try_dio;			/* try direct i/o in general? */
141 	unsigned char try_dio_now;		/* try direct i/o before next close? */
142 	unsigned char c_algo;			/* compression algorithm */
143 	unsigned char pos_unknown;			/* after reset position unknown */
144 	unsigned char sili;			/* use SILI when reading in variable b mode */
145 	unsigned char immediate_filemark;	/* write filemark immediately */
146 	int tape_type;
147 	int long_timeout;	/* timeout for commands known to take long time */
148 
149 	/* Mode characteristics */
150 	struct st_modedef modes[ST_NBR_MODES];
151 	int current_mode;
152 
153 	/* Status variables */
154 	int partition;
155 	int new_partition;
156 	int nbr_partitions;	/* zero until partition support enabled */
157 	struct st_partstat ps[ST_NBR_PARTITIONS];
158 	unsigned char dirty;
159 	unsigned char ready;
160 	unsigned char write_prot;
161 	unsigned char drv_write_prot;
162 	unsigned char in_use;
163 	unsigned char blksize_changed;
164 	unsigned char density_changed;
165 	unsigned char compression_changed;
166 	unsigned char drv_buffer;
167 	unsigned char density;
168 	unsigned char door_locked;
169 	unsigned char autorew_dev;   /* auto-rewind device */
170 	unsigned char rew_at_close;  /* rewind necessary at close */
171 	unsigned char inited;
172 	unsigned char cleaning_req;  /* cleaning requested? */
173 	int block_size;
174 	int min_block;
175 	int max_block;
176 	int recover_count;     /* From tape opening */
177 	int recover_reg;       /* From last status call */
178 
179 #if DEBUG
180 	unsigned char write_pending;
181 	int nbr_finished;
182 	int nbr_waits;
183 	int nbr_requests;
184 	int nbr_dio;
185 	int nbr_pages;
186 	unsigned char last_cmnd[6];
187 	unsigned char last_sense[16];
188 #endif
189 	char name[DISK_NAME_LEN];
190 	struct kref     kref;
191 	struct scsi_tape_stats *stats;
192 };
193 
194 /* Bit masks for use_pf */
195 #define USE_PF      1
196 #define PF_TESTED   2
197 
198 /* Values of eof */
199 #define	ST_NOEOF	0
200 #define ST_FM_HIT       1
201 #define ST_FM           2
202 #define ST_EOM_OK       3
203 #define ST_EOM_ERROR	4
204 #define	ST_EOD_1        5
205 #define ST_EOD_2        6
206 #define ST_EOD		7
207 /* EOD hit while reading => ST_EOD_1 => return zero => ST_EOD_2 =>
208    return zero => ST_EOD, return ENOSPC */
209 /* When writing: ST_EOM_OK == early warning found, write OK
210 		 ST_EOD_1  == allow trying new write after early warning
211 		 ST_EOM_ERROR == early warning found, not able to write all */
212 
213 /* Values of rw */
214 #define	ST_IDLE		0
215 #define	ST_READING	1
216 #define	ST_WRITING	2
217 
218 /* Values of ready state */
219 #define ST_READY	0
220 #define ST_NOT_READY	1
221 #define ST_NO_TAPE	2
222 
223 /* Values for door lock state */
224 #define ST_UNLOCKED	0
225 #define ST_LOCKED_EXPLICIT 1
226 #define ST_LOCKED_AUTO  2
227 #define ST_LOCK_FAILS   3
228 
229 /* Positioning SCSI-commands for Tandberg, etc. drives */
230 #define	QFA_REQUEST_BLOCK	0x02
231 #define	QFA_SEEK_BLOCK		0x0c
232 
233 /* Setting the binary options */
234 #define ST_DONT_TOUCH  0
235 #define ST_NO          1
236 #define ST_YES         2
237 
238 #define EXTENDED_SENSE_START  18
239 
240 /* Masks for some conditions in the sense data */
241 #define SENSE_FMK   0x80
242 #define SENSE_EOM   0x40
243 #define SENSE_ILI   0x20
244 
245 #endif
246