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pktcdvd.h
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1 /*
2  * Copyright (C) 2000 Jens Axboe <[email protected]>
3  * Copyright (C) 2001-2004 Peter Osterlund <[email protected]>
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 */
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