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/blkdev.h>
16#include <linux/completion.h>
17#include <linux/cdrom.h>
18#include <linux/kobject.h>
19#include <linux/sysfs.h>
20#include <linux/mempool.h>
21#include <uapi/linux/pktcdvd.h>
22
23/* default bio write queue congestion marks */
24#define PKT_WRITE_CONGESTION_ON    10000
25#define PKT_WRITE_CONGESTION_OFF   9000
26
27
28struct packet_settings
29{
30	__u32			size;		/* packet size in (512 byte) sectors */
31	__u8			fp;		/* fixed packets */
32	__u8			link_loss;	/* the rest is specified
33						 * as per Mt Fuji */
34	__u8			write_type;
35	__u8			track_mode;
36	__u8			block_mode;
37};
38
39/*
40 * Very crude stats for now
41 */
42struct packet_stats
43{
44	unsigned long		pkt_started;
45	unsigned long		pkt_ended;
46	unsigned long		secs_w;
47	unsigned long		secs_rg;
48	unsigned long		secs_r;
49};
50
51struct packet_cdrw
52{
53	struct list_head	pkt_free_list;
54	struct list_head	pkt_active_list;
55	spinlock_t		active_list_lock; /* Serialize access to pkt_active_list */
56	struct task_struct	*thread;
57	atomic_t		pending_bios;
58};
59
60/*
61 * Switch to high speed reading after reading this many kilobytes
62 * with no interspersed writes.
63 */
64#define HI_SPEED_SWITCH 512
65
66struct packet_iosched
67{
68	atomic_t		attention;	/* Set to non-zero when queue processing is needed */
69	int			writing;	/* Non-zero when writing, zero when reading */
70	spinlock_t		lock;		/* Protecting read/write queue manipulations */
71	struct bio_list		read_queue;
72	struct bio_list		write_queue;
73	sector_t		last_write;	/* The sector where the last write ended */
74	int			successive_reads;
75};
76
77/*
78 * 32 buffers of 2048 bytes
79 */
80#if (PAGE_SIZE % CD_FRAMESIZE) != 0
81#error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
82#endif
83#define PACKET_MAX_SIZE		128
84#define FRAMES_PER_PAGE		(PAGE_SIZE / CD_FRAMESIZE)
85#define PACKET_MAX_SECTORS	(PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
86
87enum packet_data_state {
88	PACKET_IDLE_STATE,			/* Not used at the moment */
89	PACKET_WAITING_STATE,			/* Waiting for more bios to arrive, so */
90						/* we don't have to do as much */
91						/* data gathering */
92	PACKET_READ_WAIT_STATE,			/* Waiting for reads to fill in holes */
93	PACKET_WRITE_WAIT_STATE,		/* Waiting for the write to complete */
94	PACKET_RECOVERY_STATE,			/* Recover after read/write errors */
95	PACKET_FINISHED_STATE,			/* After write has finished */
96
97	PACKET_NUM_STATES			/* Number of possible states */
98};
99
100/*
101 * Information needed for writing a single packet
102 */
103struct pktcdvd_device;
104
105struct packet_data
106{
107	struct list_head	list;
108
109	spinlock_t		lock;		/* Lock protecting state transitions and */
110						/* orig_bios list */
111
112	struct bio_list		orig_bios;	/* Original bios passed to pkt_make_request */
113						/* that will be handled by this packet */
114	int			write_size;	/* Total size of all bios in the orig_bios */
115						/* list, measured in number of frames */
116
117	struct bio		*w_bio;		/* The bio we will send to the real CD */
118						/* device once we have all data for the */
119						/* packet we are going to write */
120	sector_t		sector;		/* First sector in this packet */
121	int			frames;		/* Number of frames in this packet */
122
123	enum packet_data_state	state;		/* Current state */
124	atomic_t		run_sm;		/* Incremented whenever the state */
125						/* machine needs to be run */
126	long			sleep_time;	/* Set this to non-zero to make the state */
127						/* machine run after this many jiffies. */
128
129	atomic_t		io_wait;	/* Number of pending IO operations */
130	atomic_t		io_errors;	/* Number of read/write errors during IO */
131
132	struct bio		*r_bios[PACKET_MAX_SIZE]; /* bios to use during data gathering */
133	struct page		*pages[PACKET_MAX_SIZE / FRAMES_PER_PAGE];
134
135	int			cache_valid;	/* If non-zero, the data for the zone defined */
136						/* by the sector variable is completely cached */
137						/* in the pages[] vector. */
138
139	int			id;		/* ID number for debugging */
140	struct pktcdvd_device	*pd;
141};
142
143struct pkt_rb_node {
144	struct rb_node		rb_node;
145	struct bio		*bio;
146};
147
148struct packet_stacked_data
149{
150	struct bio		*bio;		/* Original read request bio */
151	struct pktcdvd_device	*pd;
152};
153#define PSD_POOL_SIZE		64
154
155struct pktcdvd_kobj
156{
157	struct kobject		kobj;
158	struct pktcdvd_device	*pd;
159};
160#define to_pktcdvdkobj(_k) \
161  ((struct pktcdvd_kobj*)container_of(_k,struct pktcdvd_kobj,kobj))
162
163struct pktcdvd_device
164{
165	struct block_device	*bdev;		/* dev attached */
166	dev_t			pkt_dev;	/* our dev */
167	char			name[20];
168	struct packet_settings	settings;
169	struct packet_stats	stats;
170	int			refcnt;		/* Open count */
171	int			write_speed;	/* current write speed, kB/s */
172	int			read_speed;	/* current read speed, kB/s */
173	unsigned long		offset;		/* start offset */
174	__u8			mode_offset;	/* 0 / 8 */
175	__u8			type;
176	unsigned long		flags;
177	__u16			mmc3_profile;
178	__u32			nwa;		/* next writable address */
179	__u32			lra;		/* last recorded address */
180	struct packet_cdrw	cdrw;
181	wait_queue_head_t	wqueue;
182
183	spinlock_t		lock;		/* Serialize access to bio_queue */
184	struct rb_root		bio_queue;	/* Work queue of bios we need to handle */
185	int			bio_queue_size;	/* Number of nodes in bio_queue */
186	sector_t		current_sector;	/* Keep track of where the elevator is */
187	atomic_t		scan_queue;	/* Set to non-zero when pkt_handle_queue */
188						/* needs to be run. */
189	mempool_t		*rb_pool;	/* mempool for pkt_rb_node allocations */
190
191	struct packet_iosched   iosched;
192	struct gendisk		*disk;
193
194	int			write_congestion_off;
195	int			write_congestion_on;
196
197	struct device		*dev;		/* sysfs pktcdvd[0-7] dev */
198	struct pktcdvd_kobj	*kobj_stat;	/* sysfs pktcdvd[0-7]/stat/     */
199	struct pktcdvd_kobj	*kobj_wqueue;	/* sysfs pktcdvd[0-7]/write_queue/ */
200
201	struct dentry		*dfs_d_root;	/* debugfs: devname directory */
202	struct dentry		*dfs_f_info;	/* debugfs: info file */
203};
204
205#endif /* __PKTCDVD_H */
206