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_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  
163  struct 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