xref: /linux/include/linux/pktcdvd.h (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2  * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
3  * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
4  *
5  * May be copied or modified under the terms of the GNU General Public
6  * License.  See linux/COPYING for more information.
7  *
8  * Packet writing layer for ATAPI and SCSI CD-R, CD-RW, DVD-R, and
9  * DVD-RW devices.
10  *
11  */
12 #ifndef __PKTCDVD_H
13 #define __PKTCDVD_H
14 
15 #include <linux/types.h>
16 
17 /*
18  * 1 for normal debug messages, 2 is very verbose. 0 to turn it off.
19  */
20 #define PACKET_DEBUG		1
21 
22 #define	MAX_WRITERS		8
23 
24 #define PKT_RB_POOL_SIZE	512
25 
26 /*
27  * How long we should hold a non-full packet before starting data gathering.
28  */
29 #define PACKET_WAIT_TIME	(HZ * 5 / 1000)
30 
31 /*
32  * use drive write caching -- we need deferred error handling to be
33  * able to sucessfully recover with this option (drive will return good
34  * status as soon as the cdb is validated).
35  */
36 #if defined(CONFIG_CDROM_PKTCDVD_WCACHE)
37 #define USE_WCACHING		1
38 #else
39 #define USE_WCACHING		0
40 #endif
41 
42 /*
43  * No user-servicable parts beyond this point ->
44  */
45 
46 /*
47  * device types
48  */
49 #define PACKET_CDR		1
50 #define	PACKET_CDRW		2
51 #define PACKET_DVDR		3
52 #define PACKET_DVDRW		4
53 
54 /*
55  * flags
56  */
57 #define PACKET_WRITABLE		1	/* pd is writable */
58 #define PACKET_NWA_VALID	2	/* next writable address valid */
59 #define PACKET_LRA_VALID	3	/* last recorded address valid */
60 #define PACKET_MERGE_SEGS	4	/* perform segment merging to keep */
61 					/* underlying cdrom device happy */
62 
63 /*
64  * Disc status -- from READ_DISC_INFO
65  */
66 #define PACKET_DISC_EMPTY	0
67 #define PACKET_DISC_INCOMPLETE	1
68 #define PACKET_DISC_COMPLETE	2
69 #define PACKET_DISC_OTHER	3
70 
71 /*
72  * write type, and corresponding data block type
73  */
74 #define PACKET_MODE1		1
75 #define PACKET_MODE2		2
76 #define PACKET_BLOCK_MODE1	8
77 #define PACKET_BLOCK_MODE2	10
78 
79 /*
80  * Last session/border status
81  */
82 #define PACKET_SESSION_EMPTY		0
83 #define PACKET_SESSION_INCOMPLETE	1
84 #define PACKET_SESSION_RESERVED		2
85 #define PACKET_SESSION_COMPLETE		3
86 
87 #define PACKET_MCN			"4a656e734178626f65323030300000"
88 
89 #undef PACKET_USE_LS
90 
91 #define PKT_CTRL_CMD_SETUP	0
92 #define PKT_CTRL_CMD_TEARDOWN	1
93 #define PKT_CTRL_CMD_STATUS	2
94 
95 struct pkt_ctrl_command {
96 	__u32 command;				/* in: Setup, teardown, status */
97 	__u32 dev_index;			/* in/out: Device index */
98 	__u32 dev;				/* in/out: Device nr for cdrw device */
99 	__u32 pkt_dev;				/* in/out: Device nr for packet device */
100 	__u32 num_devices;			/* out: Largest device index + 1 */
101 	__u32 padding;				/* Not used */
102 };
103 
104 /*
105  * packet ioctls
106  */
107 #define PACKET_IOCTL_MAGIC	('X')
108 #define PACKET_CTRL_CMD		_IOWR(PACKET_IOCTL_MAGIC, 1, struct pkt_ctrl_command)
109 
110 #ifdef __KERNEL__
111 #include <linux/blkdev.h>
112 #include <linux/completion.h>
113 #include <linux/cdrom.h>
114 
115 struct packet_settings
116 {
117 	__u32			size;		/* packet size in (512 byte) sectors */
118 	__u8			fp;		/* fixed packets */
119 	__u8			link_loss;	/* the rest is specified
120 						 * as per Mt Fuji */
121 	__u8			write_type;
122 	__u8			track_mode;
123 	__u8			block_mode;
124 };
125 
126 /*
127  * Very crude stats for now
128  */
129 struct packet_stats
130 {
131 	unsigned long		pkt_started;
132 	unsigned long		pkt_ended;
133 	unsigned long		secs_w;
134 	unsigned long		secs_rg;
135 	unsigned long		secs_r;
136 };
137 
138 struct packet_cdrw
139 {
140 	struct list_head	pkt_free_list;
141 	struct list_head	pkt_active_list;
142 	spinlock_t		active_list_lock; /* Serialize access to pkt_active_list */
143 	struct task_struct	*thread;
144 	atomic_t		pending_bios;
145 };
146 
147 /*
148  * Switch to high speed reading after reading this many kilobytes
149  * with no interspersed writes.
150  */
151 #define HI_SPEED_SWITCH 512
152 
153 struct packet_iosched
154 {
155 	atomic_t		attention;	/* Set to non-zero when queue processing is needed */
156 	int			writing;	/* Non-zero when writing, zero when reading */
157 	spinlock_t		lock;		/* Protecting read/write queue manipulations */
158 	struct bio		*read_queue;
159 	struct bio		*read_queue_tail;
160 	struct bio		*write_queue;
161 	struct bio		*write_queue_tail;
162 	sector_t		last_write;	/* The sector where the last write ended */
163 	int			successive_reads;
164 };
165 
166 /*
167  * 32 buffers of 2048 bytes
168  */
169 #if (PAGE_SIZE % CD_FRAMESIZE) != 0
170 #error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
171 #endif
172 #define PACKET_MAX_SIZE		128
173 #define FRAMES_PER_PAGE		(PAGE_SIZE / CD_FRAMESIZE)
174 #define PACKET_MAX_SECTORS	(PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
175 
176 enum packet_data_state {
177 	PACKET_IDLE_STATE,			/* Not used at the moment */
178 	PACKET_WAITING_STATE,			/* Waiting for more bios to arrive, so */
179 						/* we don't have to do as much */
180 						/* data gathering */
181 	PACKET_READ_WAIT_STATE,			/* Waiting for reads to fill in holes */
182 	PACKET_WRITE_WAIT_STATE,		/* Waiting for the write to complete */
183 	PACKET_RECOVERY_STATE,			/* Recover after read/write errors */
184 	PACKET_FINISHED_STATE,			/* After write has finished */
185 
186 	PACKET_NUM_STATES			/* Number of possible states */
187 };
188 
189 /*
190  * Information needed for writing a single packet
191  */
192 struct pktcdvd_device;
193 
194 struct packet_data
195 {
196 	struct list_head	list;
197 
198 	spinlock_t		lock;		/* Lock protecting state transitions and */
199 						/* orig_bios list */
200 
201 	struct bio		*orig_bios;	/* Original bios passed to pkt_make_request */
202 	struct bio		*orig_bios_tail;/* that will be handled by this packet */
203 	int			write_size;	/* Total size of all bios in the orig_bios */
204 						/* list, measured in number of frames */
205 
206 	struct bio		*w_bio;		/* The bio we will send to the real CD */
207 						/* device once we have all data for the */
208 						/* packet we are going to write */
209 	sector_t		sector;		/* First sector in this packet */
210 	int			frames;		/* Number of frames in this packet */
211 
212 	enum packet_data_state	state;		/* Current state */
213 	atomic_t		run_sm;		/* Incremented whenever the state */
214 						/* machine needs to be run */
215 	long			sleep_time;	/* Set this to non-zero to make the state */
216 						/* machine run after this many jiffies. */
217 
218 	atomic_t		io_wait;	/* Number of pending IO operations */
219 	atomic_t		io_errors;	/* Number of read/write errors during IO */
220 
221 	struct bio		*r_bios[PACKET_MAX_SIZE]; /* bios to use during data gathering */
222 	struct page		*pages[PACKET_MAX_SIZE / FRAMES_PER_PAGE];
223 
224 	int			cache_valid;	/* If non-zero, the data for the zone defined */
225 						/* by the sector variable is completely cached */
226 						/* in the pages[] vector. */
227 
228 	int			id;		/* ID number for debugging */
229 	struct pktcdvd_device	*pd;
230 };
231 
232 struct pkt_rb_node {
233 	struct rb_node		rb_node;
234 	struct bio		*bio;
235 };
236 
237 struct packet_stacked_data
238 {
239 	struct bio		*bio;		/* Original read request bio */
240 	struct pktcdvd_device	*pd;
241 };
242 #define PSD_POOL_SIZE		64
243 
244 struct pktcdvd_device
245 {
246 	struct block_device	*bdev;		/* dev attached */
247 	dev_t			pkt_dev;	/* our dev */
248 	char			name[20];
249 	struct packet_settings	settings;
250 	struct packet_stats	stats;
251 	int			refcnt;		/* Open count */
252 	int			write_speed;	/* current write speed, kB/s */
253 	int			read_speed;	/* current read speed, kB/s */
254 	unsigned long		offset;		/* start offset */
255 	__u8			mode_offset;	/* 0 / 8 */
256 	__u8			type;
257 	unsigned long		flags;
258 	__u16			mmc3_profile;
259 	__u32			nwa;		/* next writable address */
260 	__u32			lra;		/* last recorded address */
261 	struct packet_cdrw	cdrw;
262 	wait_queue_head_t	wqueue;
263 
264 	spinlock_t		lock;		/* Serialize access to bio_queue */
265 	struct rb_root		bio_queue;	/* Work queue of bios we need to handle */
266 	int			bio_queue_size;	/* Number of nodes in bio_queue */
267 	sector_t		current_sector;	/* Keep track of where the elevator is */
268 	atomic_t		scan_queue;	/* Set to non-zero when pkt_handle_queue */
269 						/* needs to be run. */
270 	mempool_t		*rb_pool;	/* mempool for pkt_rb_node allocations */
271 
272 	struct packet_iosched   iosched;
273 	struct gendisk		*disk;
274 };
275 
276 #endif /* __KERNEL__ */
277 
278 #endif /* __PKTCDVD_H */
279