+++ /dev/null
-#ifndef _LINUX_BLKDEV_H
-#define _LINUX_BLKDEV_H
-
-#include <linux/major.h>
-#include <linux/sched.h>
-#include <linux/genhd.h>
-#include <linux/tqueue.h>
-#include <linux/list.h>
-#include <linux/mm.h>
-
-#include <asm/io.h>
-
-struct request_queue;
-typedef struct request_queue request_queue_t;
-struct elevator_s;
-typedef struct elevator_s elevator_t;
-
-/*
- * Ok, this is an expanded form so that we can use the same
- * request for paging requests.
- */
-struct request {
- struct list_head queue;
- int elevator_sequence;
-
- volatile int rq_status; /* should split this into a few status bits */
-#define RQ_INACTIVE (-1)
-#define RQ_ACTIVE 1
-#define RQ_SCSI_BUSY 0xffff
-#define RQ_SCSI_DONE 0xfffe
-#define RQ_SCSI_DISCONNECTING 0xffe0
-
- kdev_t rq_dev;
- int cmd; /* READ or WRITE */
- int errors;
- unsigned long start_time;
- unsigned long sector;
- unsigned long nr_sectors;
- unsigned long hard_sector, hard_nr_sectors;
- unsigned int nr_segments;
- unsigned int nr_hw_segments;
- unsigned long current_nr_sectors, hard_cur_sectors;
- void * special;
- char * buffer;
- struct completion * waiting;
- struct buffer_head * bh;
- struct buffer_head * bhtail;
- request_queue_t *q;
-};
-
-#include <linux/elevator.h>
-
-typedef int (merge_request_fn) (request_queue_t *q,
- struct request *req,
- struct buffer_head *bh,
- int);
-typedef int (merge_requests_fn) (request_queue_t *q,
- struct request *req,
- struct request *req2,
- int);
-typedef void (request_fn_proc) (request_queue_t *q);
-typedef request_queue_t * (queue_proc) (kdev_t dev);
-typedef int (make_request_fn) (request_queue_t *q, int rw, struct buffer_head *bh);
-typedef void (plug_device_fn) (request_queue_t *q, kdev_t device);
-typedef void (unplug_device_fn) (void *q);
-
-struct request_list {
- unsigned int count;
- unsigned int pending[2];
- struct list_head free;
-};
-
-struct request_queue
-{
- /*
- * the queue request freelist, one for reads and one for writes
- */
- struct request_list rq;
-
- /*
- * The total number of requests on each queue
- */
- int nr_requests;
-
- /*
- * Batching threshold for sleep/wakeup decisions
- */
- int batch_requests;
-
- /*
- * The total number of 512byte blocks on each queue
- */
- atomic_t nr_sectors;
-
- /*
- * Batching threshold for sleep/wakeup decisions
- */
- int batch_sectors;
-
- /*
- * The max number of 512byte blocks on each queue
- */
- int max_queue_sectors;
-
- /*
- * Together with queue_head for cacheline sharing
- */
- struct list_head queue_head;
- elevator_t elevator;
-
- request_fn_proc * request_fn;
- merge_request_fn * back_merge_fn;
- merge_request_fn * front_merge_fn;
- merge_requests_fn * merge_requests_fn;
- make_request_fn * make_request_fn;
- plug_device_fn * plug_device_fn;
- /*
- * The queue owner gets to use this for whatever they like.
- * ll_rw_blk doesn't touch it.
- */
- void * queuedata;
-
- /*
- * This is used to remove the plug when tq_disk runs.
- */
- struct tq_struct plug_tq;
-
- /*
- * Boolean that indicates whether this queue is plugged or not.
- */
- int plugged:1;
-
- /*
- * Boolean that indicates whether current_request is active or
- * not.
- */
- int head_active:1;
-
- /*
- * Boolean that indicates you will use blk_started_sectors
- * and blk_finished_sectors in addition to blk_started_io
- * and blk_finished_io. It enables the throttling code to
- * help keep the sectors in flight to a reasonable value
- */
- int can_throttle:1;
-
- unsigned long bounce_pfn;
-
- /*
- * Is meant to protect the queue in the future instead of
- * io_request_lock
- */
- spinlock_t queue_lock;
-
- /*
- * Tasks wait here for free read and write requests
- */
- wait_queue_head_t wait_for_requests;
-};
-
-#define blk_queue_plugged(q) (q)->plugged
-#define blk_fs_request(rq) ((rq)->cmd == READ || (rq)->cmd == WRITE)
-#define blk_queue_empty(q) list_empty(&(q)->queue_head)
-
-extern inline int rq_data_dir(struct request *rq)
-{
- if (rq->cmd == READ)
- return READ;
- else if (rq->cmd == WRITE)
- return WRITE;
- else {
- BUG();
- return -1; /* ahem */
- }
-}
-
-extern unsigned long blk_max_low_pfn, blk_max_pfn;
-
-#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
-#define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
-
-extern void blk_queue_bounce_limit(request_queue_t *, u64);
-
-#ifdef CONFIG_HIGHMEM
-extern struct buffer_head *create_bounce(int, struct buffer_head *);
-extern inline struct buffer_head *blk_queue_bounce(request_queue_t *q, int rw,
- struct buffer_head *bh)
-{
- struct page *page = bh->b_page;
-
-#ifndef CONFIG_DISCONTIGMEM
- if (page - mem_map <= q->bounce_pfn)
-#else
- if ((page - page_zone(page)->zone_mem_map) + (page_zone(page)->zone_start_paddr >> PAGE_SHIFT) <= q->bounce_pfn)
-#endif
- return bh;
-
- return create_bounce(rw, bh);
-}
-#else
-#define blk_queue_bounce(q, rw, bh) (bh)
-#endif
-
-#ifdef CONFIG_XEN
-/* Used for buffer merging, where it is imperative we use machine addresses! */
-#define bh_phys(bh) (page_to_bus((bh)->b_page) + bh_offset((bh)))
-#else
-#define bh_phys(bh) (page_to_phys((bh)->b_page) + bh_offset((bh)))
-#endif
-
-#define BH_CONTIG(b1, b2) (bh_phys((b1)) + (b1)->b_size == bh_phys((b2)))
-#define BH_PHYS_4G(b1, b2) ((bh_phys((b1)) | 0xffffffff) == ((bh_phys((b2)) + (b2)->b_size - 1) | 0xffffffff))
-
-struct blk_dev_struct {
- /*
- * queue_proc has to be atomic
- */
- request_queue_t request_queue;
- queue_proc *queue;
- void *data;
-};
-
-struct sec_size {
- unsigned block_size;
- unsigned block_size_bits;
-};
-
-/*
- * Used to indicate the default queue for drivers that don't bother
- * to implement multiple queues. We have this access macro here
- * so as to eliminate the need for each and every block device
- * driver to know about the internal structure of blk_dev[].
- */
-#define BLK_DEFAULT_QUEUE(_MAJOR) &blk_dev[_MAJOR].request_queue
-
-extern struct sec_size * blk_sec[MAX_BLKDEV];
-extern struct blk_dev_struct blk_dev[MAX_BLKDEV];
-extern void grok_partitions(struct gendisk *dev, int drive, unsigned minors, long size);
-extern void register_disk(struct gendisk *dev, kdev_t first, unsigned minors, struct block_device_operations *ops, long size);
-extern void generic_make_request(int rw, struct buffer_head * bh);
-extern inline request_queue_t *blk_get_queue(kdev_t dev);
-extern void blkdev_release_request(struct request *);
-
-/*
- * Access functions for manipulating queue properties
- */
-extern int blk_grow_request_list(request_queue_t *q, int nr_requests, int max_queue_sectors);
-extern void blk_init_queue(request_queue_t *, request_fn_proc *);
-extern void blk_cleanup_queue(request_queue_t *);
-extern void blk_queue_headactive(request_queue_t *, int);
-extern void blk_queue_throttle_sectors(request_queue_t *, int);
-extern void blk_queue_make_request(request_queue_t *, make_request_fn *);
-extern void generic_unplug_device(void *);
-extern inline int blk_seg_merge_ok(struct buffer_head *, struct buffer_head *);
-
-extern int * blk_size[MAX_BLKDEV];
-
-extern int * blksize_size[MAX_BLKDEV];
-
-extern int * hardsect_size[MAX_BLKDEV];
-
-extern int * max_readahead[MAX_BLKDEV];
-
-extern int * max_sectors[MAX_BLKDEV];
-
-extern int * max_segments[MAX_BLKDEV];
-
-#define MAX_SEGMENTS 128
-#define MAX_SECTORS 255
-#define MAX_QUEUE_SECTORS (4 << (20 - 9)) /* 4 mbytes when full sized */
-#define MAX_NR_REQUESTS 1024 /* 1024k when in 512 units, normally min is 1M in 1k units */
-
-#define PageAlignSize(size) (((size) + PAGE_SIZE -1) & PAGE_MASK)
-
-#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queue)
-#define blkdev_entry_next_request(entry) blkdev_entry_to_request((entry)->next)
-#define blkdev_entry_prev_request(entry) blkdev_entry_to_request((entry)->prev)
-#define blkdev_next_request(req) blkdev_entry_to_request((req)->queue.next)
-#define blkdev_prev_request(req) blkdev_entry_to_request((req)->queue.prev)
-
-extern void drive_stat_acct (kdev_t dev, int rw,
- unsigned long nr_sectors, int new_io);
-
-static inline int get_hardsect_size(kdev_t dev)
-{
- int retval = 512;
- int major = MAJOR(dev);
-
- if (hardsect_size[major]) {
- int minor = MINOR(dev);
- if (hardsect_size[major][minor])
- retval = hardsect_size[major][minor];
- }
- return retval;
-}
-
-static inline int blk_oversized_queue(request_queue_t * q)
-{
- if (q->can_throttle)
- return atomic_read(&q->nr_sectors) > q->max_queue_sectors;
- return q->rq.count == 0;
-}
-
-static inline int blk_oversized_queue_reads(request_queue_t * q)
-{
- if (q->can_throttle)
- return atomic_read(&q->nr_sectors) > q->max_queue_sectors + q->batch_sectors;
- return q->rq.count == 0;
-}
-
-static inline int blk_oversized_queue_batch(request_queue_t * q)
-{
- return atomic_read(&q->nr_sectors) > q->max_queue_sectors - q->batch_sectors;
-}
-
-#define blk_finished_io(nsects) do { } while (0)
-#define blk_started_io(nsects) do { } while (0)
-
-static inline void blk_started_sectors(struct request *rq, int count)
-{
- request_queue_t *q = rq->q;
- if (q && q->can_throttle) {
- atomic_add(count, &q->nr_sectors);
- if (atomic_read(&q->nr_sectors) < 0) {
- printk("nr_sectors is %d\n", atomic_read(&q->nr_sectors));
- BUG();
- }
- }
-}
-
-static inline void blk_finished_sectors(struct request *rq, int count)
-{
- request_queue_t *q = rq->q;
- if (q && q->can_throttle) {
- atomic_sub(count, &q->nr_sectors);
-
- smp_mb();
- if (q->rq.count >= q->batch_requests && !blk_oversized_queue_batch(q)) {
- if (waitqueue_active(&q->wait_for_requests))
- wake_up(&q->wait_for_requests);
- }
- if (atomic_read(&q->nr_sectors) < 0) {
- printk("nr_sectors is %d\n", atomic_read(&q->nr_sectors));
- BUG();
- }
- }
-}
-
-static inline unsigned int blksize_bits(unsigned int size)
-{
- unsigned int bits = 8;
- do {
- bits++;
- size >>= 1;
- } while (size > 256);
- return bits;
-}
-
-static inline unsigned int block_size(kdev_t dev)
-{
- int retval = BLOCK_SIZE;
- int major = MAJOR(dev);
-
- if (blksize_size[major]) {
- int minor = MINOR(dev);
- if (blksize_size[major][minor])
- retval = blksize_size[major][minor];
- }
- return retval;
-}
-
-#endif
projects / xen.git / commitdiff