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 
28 struct 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  */
42 struct 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 
51 struct 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 
66 struct 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 
87 enum 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  */
103 struct pktcdvd_device;
104 
105 struct 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 
143 struct pkt_rb_node {
144 	struct rb_node		rb_node;
145 	struct bio		*bio;
146 };
147 
148 struct 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 
155 struct pktcdvd_device
156 {
157 	struct block_device	*bdev;		/* dev attached */
158 	dev_t			pkt_dev;	/* our dev */
159 	char			name[20];
160 	struct packet_settings	settings;
161 	struct packet_stats	stats;
162 	int			refcnt;		/* Open count */
163 	int			write_speed;	/* current write speed, kB/s */
164 	int			read_speed;	/* current read speed, kB/s */
165 	unsigned long		offset;		/* start offset */
166 	__u8			mode_offset;	/* 0 / 8 */
167 	__u8			type;
168 	unsigned long		flags;
169 	__u16			mmc3_profile;
170 	__u32			nwa;		/* next writable address */
171 	__u32			lra;		/* last recorded address */
172 	struct packet_cdrw	cdrw;
173 	wait_queue_head_t	wqueue;
174 
175 	spinlock_t		lock;		/* Serialize access to bio_queue */
176 	struct rb_root		bio_queue;	/* Work queue of bios we need to handle */
177 	int			bio_queue_size;	/* Number of nodes in bio_queue */
178 	bool			congested;	/* Someone is waiting for bio_queue_size
179 						 * to drop. */
180 	sector_t		current_sector;	/* Keep track of where the elevator is */
181 	atomic_t		scan_queue;	/* Set to non-zero when pkt_handle_queue */
182 						/* needs to be run. */
183 	mempool_t		rb_pool;	/* mempool for pkt_rb_node allocations */
184 
185 	struct packet_iosched   iosched;
186 	struct gendisk		*disk;
187 
188 	int			write_congestion_off;
189 	int			write_congestion_on;
190 
191 	struct device		*dev;		/* sysfs pktcdvd[0-7] dev */
192 
193 	struct dentry		*dfs_d_root;	/* debugfs: devname directory */
194 	struct dentry		*dfs_f_info;	/* debugfs: info file */
195 };
196 
197 #endif /* __PKTCDVD_H */
198