xref: /openbmc/linux/drivers/scsi/st.h (revision d9fd5a71)
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 dma;	/* DMA-able buffer */
39 	unsigned char cleared;  /* internal buffer cleared after open? */
40 	unsigned short do_dio;  /* direct i/o set up? */
41 	int buffer_size;
42 	int buffer_blocks;
43 	int buffer_bytes;
44 	int read_pointer;
45 	int writing;
46 	int syscall_result;
47 	struct st_request *last_SRpnt;
48 	struct st_cmdstatus cmdstat;
49 	struct page **reserved_pages;
50 	int reserved_page_order;
51 	struct page **mapped_pages;
52 	struct rq_map_data map_data;
53 	unsigned char *b_data;
54 	unsigned short use_sg;	/* zero or max number of s/g segments for this adapter */
55 	unsigned short sg_segs;		/* number of segments in s/g list */
56 	unsigned short frp_segs;	/* number of buffer segments */
57 };
58 
59 /* The tape mode definition */
60 struct st_modedef {
61 	unsigned char defined;
62 	unsigned char sysv;	/* SYS V semantics? */
63 	unsigned char do_async_writes;
64 	unsigned char do_buffer_writes;
65 	unsigned char do_read_ahead;
66 	unsigned char defaults_for_writes;
67 	unsigned char default_compression;	/* 0 = don't touch, etc */
68 	short default_density;	/* Forced density, -1 = no value */
69 	int default_blksize;	/* Forced blocksize, -1 = no value */
70 	struct scsi_tape *tape;
71 	struct device *devs[2];  /* Auto-rewind and non-rewind devices */
72 	struct cdev *cdevs[2];  /* Auto-rewind and non-rewind devices */
73 };
74 
75 /* Number of modes can be changed by changing ST_NBR_MODE_BITS. The maximum
76    number of modes is 16 (ST_NBR_MODE_BITS 4) */
77 #define ST_NBR_MODE_BITS 2
78 #define ST_NBR_MODES (1 << ST_NBR_MODE_BITS)
79 #define ST_MODE_SHIFT (7 - ST_NBR_MODE_BITS)
80 #define ST_MODE_MASK ((ST_NBR_MODES - 1) << ST_MODE_SHIFT)
81 
82 #define ST_MAX_TAPES (1 << (20 - (ST_NBR_MODE_BITS + 1)))
83 #define ST_MAX_TAPE_ENTRIES  (ST_MAX_TAPES << (ST_NBR_MODE_BITS + 1))
84 
85 /* The status related to each partition */
86 struct st_partstat {
87 	unsigned char rw;
88 	unsigned char eof;
89 	unsigned char at_sm;
90 	unsigned char last_block_valid;
91 	u32 last_block_visited;
92 	int drv_block;		/* The block where the drive head is */
93 	int drv_file;
94 };
95 
96 /* Tape statistics */
97 struct scsi_tape_stats {
98 	atomic64_t read_byte_cnt;  /* bytes read */
99 	atomic64_t write_byte_cnt; /* bytes written */
100 	atomic64_t in_flight;      /* Number of I/Os in flight */
101 	atomic64_t read_cnt;       /* Count of read requests */
102 	atomic64_t write_cnt;      /* Count of write requests */
103 	atomic64_t other_cnt;      /* Count of other requests either
104 				    * implicit or from user space
105 				    * ioctl. */
106 	atomic64_t resid_cnt;      /* Count of resid_len > 0 */
107 	atomic64_t tot_read_time;  /* ktime spent completing reads */
108 	atomic64_t tot_write_time; /* ktime spent completing writes */
109 	atomic64_t tot_io_time;    /* ktime spent doing any I/O */
110 	ktime_t read_time;         /* holds ktime request was queued */
111 	ktime_t write_time;        /* holds ktime request was queued */
112 	ktime_t other_time;        /* holds ktime request was queued */
113 	atomic_t last_read_size;   /* Number of bytes issued for last read */
114 	atomic_t last_write_size;  /* Number of bytes issued for last write */
115 };
116 
117 #define ST_NBR_PARTITIONS 4
118 
119 /* The tape drive descriptor */
120 struct scsi_tape {
121 	struct scsi_driver *driver;
122 	struct scsi_device *device;
123 	struct mutex lock;	/* For serialization */
124 	struct completion wait;	/* For SCSI commands */
125 	struct st_buffer *buffer;
126 	int index;
127 
128 	/* Drive characteristics */
129 	unsigned char omit_blklims;
130 	unsigned char do_auto_lock;
131 	unsigned char can_bsr;
132 	unsigned char can_partitions;
133 	unsigned char two_fm;
134 	unsigned char fast_mteom;
135 	unsigned char immediate;
136 	unsigned char restr_dma;
137 	unsigned char scsi2_logical;
138 	unsigned char default_drvbuffer;	/* 0xff = don't touch, value 3 bits */
139 	unsigned char cln_mode;			/* 0 = none, otherwise sense byte nbr */
140 	unsigned char cln_sense_value;
141 	unsigned char cln_sense_mask;
142 	unsigned char use_pf;			/* Set Page Format bit in all mode selects? */
143 	unsigned char try_dio;			/* try direct i/o in general? */
144 	unsigned char try_dio_now;		/* try direct i/o before next close? */
145 	unsigned char c_algo;			/* compression algorithm */
146 	unsigned char pos_unknown;			/* after reset position unknown */
147 	unsigned char sili;			/* use SILI when reading in variable b mode */
148 	unsigned char immediate_filemark;	/* write filemark immediately */
149 	int tape_type;
150 	int long_timeout;	/* timeout for commands known to take long time */
151 
152 	/* Mode characteristics */
153 	struct st_modedef modes[ST_NBR_MODES];
154 	int current_mode;
155 
156 	/* Status variables */
157 	int partition;
158 	int new_partition;
159 	int nbr_partitions;	/* zero until partition support enabled */
160 	struct st_partstat ps[ST_NBR_PARTITIONS];
161 	unsigned char dirty;
162 	unsigned char ready;
163 	unsigned char write_prot;
164 	unsigned char drv_write_prot;
165 	unsigned char in_use;
166 	unsigned char blksize_changed;
167 	unsigned char density_changed;
168 	unsigned char compression_changed;
169 	unsigned char drv_buffer;
170 	unsigned char density;
171 	unsigned char door_locked;
172 	unsigned char autorew_dev;   /* auto-rewind device */
173 	unsigned char rew_at_close;  /* rewind necessary at close */
174 	unsigned char inited;
175 	unsigned char cleaning_req;  /* cleaning requested? */
176 	int block_size;
177 	int min_block;
178 	int max_block;
179 	int recover_count;     /* From tape opening */
180 	int recover_reg;       /* From last status call */
181 
182 #if DEBUG
183 	unsigned char write_pending;
184 	int nbr_finished;
185 	int nbr_waits;
186 	int nbr_requests;
187 	int nbr_dio;
188 	int nbr_pages;
189 	unsigned char last_cmnd[6];
190 	unsigned char last_sense[16];
191 #endif
192 	struct gendisk *disk;
193 	struct kref     kref;
194 	struct scsi_tape_stats *stats;
195 };
196 
197 /* Bit masks for use_pf */
198 #define USE_PF      1
199 #define PF_TESTED   2
200 
201 /* Values of eof */
202 #define	ST_NOEOF	0
203 #define ST_FM_HIT       1
204 #define ST_FM           2
205 #define ST_EOM_OK       3
206 #define ST_EOM_ERROR	4
207 #define	ST_EOD_1        5
208 #define ST_EOD_2        6
209 #define ST_EOD		7
210 /* EOD hit while reading => ST_EOD_1 => return zero => ST_EOD_2 =>
211    return zero => ST_EOD, return ENOSPC */
212 /* When writing: ST_EOM_OK == early warning found, write OK
213 		 ST_EOD_1  == allow trying new write after early warning
214 		 ST_EOM_ERROR == early warning found, not able to write all */
215 
216 /* Values of rw */
217 #define	ST_IDLE		0
218 #define	ST_READING	1
219 #define	ST_WRITING	2
220 
221 /* Values of ready state */
222 #define ST_READY	0
223 #define ST_NOT_READY	1
224 #define ST_NO_TAPE	2
225 
226 /* Values for door lock state */
227 #define ST_UNLOCKED	0
228 #define ST_LOCKED_EXPLICIT 1
229 #define ST_LOCKED_AUTO  2
230 #define ST_LOCK_FAILS   3
231 
232 /* Positioning SCSI-commands for Tandberg, etc. drives */
233 #define	QFA_REQUEST_BLOCK	0x02
234 #define	QFA_SEEK_BLOCK		0x0c
235 
236 /* Setting the binary options */
237 #define ST_DONT_TOUCH  0
238 #define ST_NO          1
239 #define ST_YES         2
240 
241 #define EXTENDED_SENSE_START  18
242 
243 /* Masks for some conditions in the sense data */
244 #define SENSE_FMK   0x80
245 #define SENSE_EOM   0x40
246 #define SENSE_ILI   0x20
247 
248 #endif
249