![Peter Osterlund](/assets/img/avatar_default.png)
Allocate memory for read-gathering at open time, when it is known just how much memory is needed. This avoids wasting kernel memory when the real packet size is smaller than the maximum packet size supported by the driver. This is always the case when using DVD discs. Signed-off-by: Peter Osterlund <petero2@telia.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
279 lines
7.4 KiB
C
279 lines
7.4 KiB
C
/*
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* Copyright (C) 2000 Jens Axboe <axboe@suse.de>
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* Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
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*
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* May be copied or modified under the terms of the GNU General Public
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* License. See linux/COPYING for more information.
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*
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* Packet writing layer for ATAPI and SCSI CD-R, CD-RW, DVD-R, and
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* DVD-RW devices.
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*
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*/
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#ifndef __PKTCDVD_H
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#define __PKTCDVD_H
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#include <linux/types.h>
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/*
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* 1 for normal debug messages, 2 is very verbose. 0 to turn it off.
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*/
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#define PACKET_DEBUG 1
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#define MAX_WRITERS 8
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#define PKT_RB_POOL_SIZE 512
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/*
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* How long we should hold a non-full packet before starting data gathering.
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*/
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#define PACKET_WAIT_TIME (HZ * 5 / 1000)
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/*
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* use drive write caching -- we need deferred error handling to be
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* able to sucessfully recover with this option (drive will return good
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* status as soon as the cdb is validated).
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*/
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#if defined(CONFIG_CDROM_PKTCDVD_WCACHE)
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#define USE_WCACHING 1
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#else
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#define USE_WCACHING 0
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#endif
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/*
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* No user-servicable parts beyond this point ->
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*/
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/*
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* device types
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*/
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#define PACKET_CDR 1
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#define PACKET_CDRW 2
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#define PACKET_DVDR 3
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#define PACKET_DVDRW 4
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/*
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* flags
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*/
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#define PACKET_WRITABLE 1 /* pd is writable */
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#define PACKET_NWA_VALID 2 /* next writable address valid */
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#define PACKET_LRA_VALID 3 /* last recorded address valid */
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#define PACKET_MERGE_SEGS 4 /* perform segment merging to keep */
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/* underlying cdrom device happy */
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/*
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* Disc status -- from READ_DISC_INFO
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*/
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#define PACKET_DISC_EMPTY 0
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#define PACKET_DISC_INCOMPLETE 1
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#define PACKET_DISC_COMPLETE 2
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#define PACKET_DISC_OTHER 3
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/*
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* write type, and corresponding data block type
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*/
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#define PACKET_MODE1 1
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#define PACKET_MODE2 2
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#define PACKET_BLOCK_MODE1 8
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#define PACKET_BLOCK_MODE2 10
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/*
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* Last session/border status
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*/
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#define PACKET_SESSION_EMPTY 0
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#define PACKET_SESSION_INCOMPLETE 1
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#define PACKET_SESSION_RESERVED 2
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#define PACKET_SESSION_COMPLETE 3
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#define PACKET_MCN "4a656e734178626f65323030300000"
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#undef PACKET_USE_LS
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#define PKT_CTRL_CMD_SETUP 0
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#define PKT_CTRL_CMD_TEARDOWN 1
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#define PKT_CTRL_CMD_STATUS 2
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struct pkt_ctrl_command {
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__u32 command; /* in: Setup, teardown, status */
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__u32 dev_index; /* in/out: Device index */
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__u32 dev; /* in/out: Device nr for cdrw device */
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__u32 pkt_dev; /* in/out: Device nr for packet device */
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__u32 num_devices; /* out: Largest device index + 1 */
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__u32 padding; /* Not used */
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};
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/*
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* packet ioctls
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*/
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#define PACKET_IOCTL_MAGIC ('X')
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#define PACKET_CTRL_CMD _IOWR(PACKET_IOCTL_MAGIC, 1, struct pkt_ctrl_command)
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#ifdef __KERNEL__
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#include <linux/blkdev.h>
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#include <linux/completion.h>
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#include <linux/cdrom.h>
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struct packet_settings
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{
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__u32 size; /* packet size in (512 byte) sectors */
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__u8 fp; /* fixed packets */
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__u8 link_loss; /* the rest is specified
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* as per Mt Fuji */
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__u8 write_type;
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__u8 track_mode;
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__u8 block_mode;
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};
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/*
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* Very crude stats for now
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*/
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struct packet_stats
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{
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unsigned long pkt_started;
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unsigned long pkt_ended;
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unsigned long secs_w;
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unsigned long secs_rg;
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unsigned long secs_r;
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};
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struct packet_cdrw
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{
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struct list_head pkt_free_list;
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struct list_head pkt_active_list;
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spinlock_t active_list_lock; /* Serialize access to pkt_active_list */
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struct task_struct *thread;
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atomic_t pending_bios;
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};
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/*
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* Switch to high speed reading after reading this many kilobytes
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* with no interspersed writes.
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*/
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#define HI_SPEED_SWITCH 512
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struct packet_iosched
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{
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atomic_t attention; /* Set to non-zero when queue processing is needed */
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int writing; /* Non-zero when writing, zero when reading */
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spinlock_t lock; /* Protecting read/write queue manipulations */
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struct bio *read_queue;
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struct bio *read_queue_tail;
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struct bio *write_queue;
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struct bio *write_queue_tail;
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sector_t last_write; /* The sector where the last write ended */
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int successive_reads;
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};
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/*
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* 32 buffers of 2048 bytes
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*/
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#if (PAGE_SIZE % CD_FRAMESIZE) != 0
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#error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
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#endif
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#define PACKET_MAX_SIZE 32
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#define FRAMES_PER_PAGE (PAGE_SIZE / CD_FRAMESIZE)
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#define PACKET_MAX_SECTORS (PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
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enum packet_data_state {
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PACKET_IDLE_STATE, /* Not used at the moment */
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PACKET_WAITING_STATE, /* Waiting for more bios to arrive, so */
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/* we don't have to do as much */
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/* data gathering */
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PACKET_READ_WAIT_STATE, /* Waiting for reads to fill in holes */
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PACKET_WRITE_WAIT_STATE, /* Waiting for the write to complete */
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PACKET_RECOVERY_STATE, /* Recover after read/write errors */
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PACKET_FINISHED_STATE, /* After write has finished */
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PACKET_NUM_STATES /* Number of possible states */
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};
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/*
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* Information needed for writing a single packet
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*/
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struct pktcdvd_device;
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struct packet_data
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{
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struct list_head list;
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spinlock_t lock; /* Lock protecting state transitions and */
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/* orig_bios list */
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struct bio *orig_bios; /* Original bios passed to pkt_make_request */
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struct bio *orig_bios_tail;/* that will be handled by this packet */
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int write_size; /* Total size of all bios in the orig_bios */
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/* list, measured in number of frames */
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struct bio *w_bio; /* The bio we will send to the real CD */
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/* device once we have all data for the */
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/* packet we are going to write */
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sector_t sector; /* First sector in this packet */
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int frames; /* Number of frames in this packet */
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enum packet_data_state state; /* Current state */
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atomic_t run_sm; /* Incremented whenever the state */
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/* machine needs to be run */
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long sleep_time; /* Set this to non-zero to make the state */
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/* machine run after this many jiffies. */
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atomic_t io_wait; /* Number of pending IO operations */
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atomic_t io_errors; /* Number of read/write errors during IO */
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struct bio *r_bios[PACKET_MAX_SIZE]; /* bios to use during data gathering */
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struct page *pages[PACKET_MAX_SIZE / FRAMES_PER_PAGE];
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int cache_valid; /* If non-zero, the data for the zone defined */
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/* by the sector variable is completely cached */
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/* in the pages[] vector. */
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int id; /* ID number for debugging */
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struct pktcdvd_device *pd;
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};
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struct pkt_rb_node {
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struct rb_node rb_node;
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struct bio *bio;
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};
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struct packet_stacked_data
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{
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struct bio *bio; /* Original read request bio */
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struct pktcdvd_device *pd;
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};
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#define PSD_POOL_SIZE 64
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struct pktcdvd_device
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{
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struct block_device *bdev; /* dev attached */
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dev_t pkt_dev; /* our dev */
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char name[20];
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struct packet_settings settings;
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struct packet_stats stats;
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int refcnt; /* Open count */
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int write_speed; /* current write speed, kB/s */
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int read_speed; /* current read speed, kB/s */
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unsigned long offset; /* start offset */
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__u8 mode_offset; /* 0 / 8 */
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__u8 type;
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unsigned long flags;
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__u16 mmc3_profile;
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__u32 nwa; /* next writable address */
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__u32 lra; /* last recorded address */
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struct packet_cdrw cdrw;
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wait_queue_head_t wqueue;
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spinlock_t lock; /* Serialize access to bio_queue */
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struct rb_root bio_queue; /* Work queue of bios we need to handle */
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int bio_queue_size; /* Number of nodes in bio_queue */
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sector_t current_sector; /* Keep track of where the elevator is */
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atomic_t scan_queue; /* Set to non-zero when pkt_handle_queue */
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/* needs to be run. */
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mempool_t *rb_pool; /* mempool for pkt_rb_node allocations */
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struct packet_iosched iosched;
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struct gendisk *disk;
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};
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#endif /* __KERNEL__ */
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#endif /* __PKTCDVD_H */
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