blk.h

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

/* Is this okay? by OKUJI Yoshinori */
#ifndef _BLK_H
#define _BLK_H

#include <linux/blkdev.h>
#include <linux/locks.h>
#include <linux/malloc.h>
#include <linux/config.h>
#include <linux/md.h>

/*
 * NR_REQUEST is the number of entries in the request-queue.
 * NOTE that writes may use only the low 2/3 of these: reads
 * take precedence.
 */
#define NR_REQUEST	64

/*
 * This is used in the elevator algorithm.  We don't prioritise reads
 * over writes any more --- although reads are more time-critical than
 * writes, by treating them equally we increase filesystem throughput.
 * This turns out to give better overall performance.  -- sct
 */
#define IN_ORDER(s1,s2) \
((s1)->rq_dev < (s2)->rq_dev || (((s1)->rq_dev == (s2)->rq_dev && \
(s1)->sector < (s2)->sector)))

/*
 * These will have to be changed to be aware of different buffer
 * sizes etc.. It actually needs a major cleanup.
 */
#if defined(IDE_DRIVER) || defined(MD_DRIVER)
#define SECTOR_MASK ((BLOCK_SIZE >> 9) - 1)
#else
#define SECTOR_MASK (blksize_size[MAJOR_NR] &&     \
	blksize_size[MAJOR_NR][MINOR(CURRENT->rq_dev)] ? \
	((blksize_size[MAJOR_NR][MINOR(CURRENT->rq_dev)] >> 9) - 1) :  \
	((BLOCK_SIZE >> 9)  -  1))
#endif /* IDE_DRIVER */

#define SUBSECTOR(block) (CURRENT->current_nr_sectors > 0)

#ifdef CONFIG_CDU31A
extern int cdu31a_init(void);
#endif /* CONFIG_CDU31A */
#ifdef CONFIG_MCD
extern int mcd_init(void);
#endif /* CONFIG_MCD */
#ifdef CONFIG_MCDX
extern int mcdx_init(void);
#endif /* CONFIG_MCDX */
#ifdef CONFIG_SBPCD
extern int sbpcd_init(void);
#endif /* CONFIG_SBPCD */
#ifdef CONFIG_AZTCD
extern int aztcd_init(void);
#endif /* CONFIG_AZTCD */
#ifdef CONFIG_CDU535
extern int sony535_init(void);
#endif /* CONFIG_CDU535 */
#ifdef CONFIG_GSCD
extern int gscd_init(void);
#endif /* CONFIG_GSCD */
#ifdef CONFIG_CM206
extern int cm206_init(void);
#endif /* CONFIG_CM206 */
#ifdef CONFIG_OPTCD
extern int optcd_init(void);
#endif /* CONFIG_OPTCD */
#ifdef CONFIG_SJCD
extern int sjcd_init(void);
#endif /* CONFIG_SJCD */
#ifdef CONFIG_CDI_INIT
extern int cdi_init(void);
#endif /* CONFIG_CDI_INIT */
#ifdef CONFIG_BLK_DEV_HD
extern int hd_init(void);
#endif
#ifdef CONFIG_BLK_DEV_IDE
extern int ide_init(void);
#endif
#ifdef CONFIG_BLK_DEV_XD
extern int xd_init(void);
#endif
#ifdef CONFIG_BLK_DEV_LOOP
extern int loop_init(void);
#endif
#ifdef CONFIG_BLK_DEV_MD
extern int md_init(void);
#endif /* CONFIG_BLK_DEV_MD */

extern void set_device_ro(kdev_t dev,int flag);
void add_blkdev_randomness(int major);

extern int floppy_init(void);
extern void rd_load(void);
extern int rd_init(void);
extern int rd_doload;		/* 1 = load ramdisk, 0 = don't load */
extern int rd_prompt;		/* 1 = prompt for ramdisk, 0 = don't prompt */
extern int rd_image_start;	/* starting block # of image */

#ifdef CONFIG_BLK_DEV_INITRD

#define INITRD_MINOR 250 /* shouldn't collide with /dev/ram* too soon ... */

extern unsigned long initrd_start,initrd_end;
extern int mount_initrd; /* zero if initrd should not be mounted */
void initrd_init(void);

#endif

#define RO_IOCTLS(dev,where) \
  case BLKROSET: { int __err;  if (!suser()) return -EACCES; \
		   __err = verify_area(VERIFY_READ, (void *) (where), sizeof(long)); \
		   if (!__err) set_device_ro((dev),get_fs_long((long *) (where))); return __err; } \
  case BLKROGET: { int __err = verify_area(VERIFY_WRITE, (void *) (where), sizeof(long)); \
		   if (!__err) put_fs_long(0!=is_read_only(dev),(long *) (where)); return __err; }

#if defined(MAJOR_NR) || defined(IDE_DRIVER)

/*
 * Add entries as needed.
 */

#ifdef IDE_DRIVER

#define DEVICE_NR(device)	(MINOR(device) >> PARTN_BITS)
#define DEVICE_ON(device)	/* nothing */
#define DEVICE_OFF(device)	/* nothing */

#elif (MAJOR_NR == RAMDISK_MAJOR)

/* ram disk */
#define DEVICE_NAME "ramdisk"
#define DEVICE_REQUEST rd_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)
#define DEVICE_NO_RANDOM

#elif (MAJOR_NR == FLOPPY_MAJOR)

static void floppy_off(unsigned int nr);

#define DEVICE_NAME "floppy"
#define DEVICE_INTR do_floppy
#define DEVICE_REQUEST do_fd_request
#define DEVICE_NR(device) ( (MINOR(device) & 3) | ((MINOR(device) & 0x80 ) >> 5 ))
#define DEVICE_ON(device)
#define DEVICE_OFF(device) floppy_off(DEVICE_NR(device))

#elif (MAJOR_NR == HD_MAJOR)

/* harddisk: timeout is 6 seconds.. */
#define DEVICE_NAME "harddisk"
#define DEVICE_INTR do_hd
#define DEVICE_TIMEOUT HD_TIMER
#define TIMEOUT_VALUE (6*HZ)
#define DEVICE_REQUEST do_hd_request
#define DEVICE_NR(device) (MINOR(device)>>6)
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == SCSI_DISK_MAJOR)

#define DEVICE_NAME "scsidisk"
#define DEVICE_INTR do_sd
#define TIMEOUT_VALUE (2*HZ)
#define DEVICE_REQUEST do_sd_request
#define DEVICE_NR(device) (MINOR(device) >> 4)
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

/* Kludge to use the same number for both char and block major numbers */
#elif  (MAJOR_NR == MD_MAJOR) && defined(MD_DRIVER)

#define DEVICE_NAME "Multiple devices driver"
#define DEVICE_REQUEST do_md_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == SCSI_TAPE_MAJOR)

#define DEVICE_NAME "scsitape"
#define DEVICE_INTR do_st
#define DEVICE_NR(device) (MINOR(device) & 0x7f)
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == SCSI_CDROM_MAJOR)

#define DEVICE_NAME "CD-ROM"
#define DEVICE_INTR do_sr
#define DEVICE_REQUEST do_sr_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == XT_DISK_MAJOR)

#define DEVICE_NAME "xt disk"
#define DEVICE_REQUEST do_xd_request
#define DEVICE_NR(device) (MINOR(device) >> 6)
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == CDU31A_CDROM_MAJOR)

#define DEVICE_NAME "CDU31A"
#define DEVICE_REQUEST do_cdu31a_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == MITSUMI_CDROM_MAJOR)

#define DEVICE_NAME "Mitsumi CD-ROM"
/* #define DEVICE_INTR do_mcd */
#define DEVICE_REQUEST do_mcd_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == MITSUMI_X_CDROM_MAJOR)

#define DEVICE_NAME "Mitsumi CD-ROM"
/* #define DEVICE_INTR do_mcdx */
#define DEVICE_REQUEST do_mcdx_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == MATSUSHITA_CDROM_MAJOR)

#define DEVICE_NAME "Matsushita CD-ROM controller #1"
#define DEVICE_REQUEST do_sbpcd_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == MATSUSHITA_CDROM2_MAJOR)

#define DEVICE_NAME "Matsushita CD-ROM controller #2"
#define DEVICE_REQUEST do_sbpcd2_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == MATSUSHITA_CDROM3_MAJOR)

#define DEVICE_NAME "Matsushita CD-ROM controller #3"
#define DEVICE_REQUEST do_sbpcd3_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == MATSUSHITA_CDROM4_MAJOR)

#define DEVICE_NAME "Matsushita CD-ROM controller #4"
#define DEVICE_REQUEST do_sbpcd4_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == AZTECH_CDROM_MAJOR)

#define DEVICE_NAME "Aztech CD-ROM"
#define DEVICE_REQUEST do_aztcd_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == CDU535_CDROM_MAJOR)

#define DEVICE_NAME "SONY-CDU535"
#define DEVICE_INTR do_cdu535
#define DEVICE_REQUEST do_cdu535_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == GOLDSTAR_CDROM_MAJOR)

#define DEVICE_NAME "Goldstar R420"
#define DEVICE_REQUEST do_gscd_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == CM206_CDROM_MAJOR)
#define DEVICE_NAME "Philips/LMS cd-rom cm206"
#define DEVICE_REQUEST do_cm206_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == OPTICS_CDROM_MAJOR)

#define DEVICE_NAME "DOLPHIN 8000AT CD-ROM"
#define DEVICE_REQUEST do_optcd_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#elif (MAJOR_NR == SANYO_CDROM_MAJOR)

#define DEVICE_NAME "Sanyo H94A CD-ROM"
#define DEVICE_REQUEST do_sjcd_request
#define DEVICE_NR(device) (MINOR(device))
#define DEVICE_ON(device)
#define DEVICE_OFF(device)

#endif /* MAJOR_NR == whatever */

#if (MAJOR_NR != SCSI_TAPE_MAJOR)
#if !defined(IDE_DRIVER)

#ifndef CURRENT
#define CURRENT (blk_dev[MAJOR_NR].current_request)
#endif

#define CURRENT_DEV DEVICE_NR(CURRENT->rq_dev)

#ifdef DEVICE_INTR
static void (*DEVICE_INTR)(void) = NULL;
#endif
#ifdef DEVICE_TIMEOUT

#define SET_TIMER \
((timer_table[DEVICE_TIMEOUT].expires = jiffies + TIMEOUT_VALUE), \
(timer_active |= 1<<DEVICE_TIMEOUT))

#define CLEAR_TIMER \
timer_active &= ~(1<<DEVICE_TIMEOUT)

#define SET_INTR(x) \
if ((DEVICE_INTR = (x)) != NULL) \
	SET_TIMER; \
else \
	CLEAR_TIMER;

#else

#define SET_INTR(x) (DEVICE_INTR = (x))

#endif /* DEVICE_TIMEOUT */

static void (DEVICE_REQUEST)(void);

#ifdef DEVICE_INTR
#define CLEAR_INTR SET_INTR(NULL)
#else
#define CLEAR_INTR
#endif

#define INIT_REQUEST \
	if (!CURRENT) {\
		CLEAR_INTR; \
		return; \
	} \
	if (MAJOR(CURRENT->rq_dev) != MAJOR_NR) \
		panic(DEVICE_NAME ": request list destroyed"); \
	if (CURRENT->bh) { \
		if (!buffer_locked(CURRENT->bh)) \
			panic(DEVICE_NAME ": block not locked"); \
	}

#endif /* !defined(IDE_DRIVER) */

/* end_request() - SCSI devices have their own version */
/*               - IDE drivers have their own copy too */

#if ! SCSI_BLK_MAJOR(MAJOR_NR)

#if defined(IDE_DRIVER) && !defined(_IDE_C) /* shared copy for IDE modules */
void ide_end_request(byte uptodate, ide_hwgroup_t *hwgroup);
#else

#ifdef IDE_DRIVER
void ide_end_request(byte uptodate, ide_hwgroup_t *hwgroup) {
	struct request *req = hwgroup->rq;
#else
static void end_request(int uptodate) {
	struct request *req = CURRENT;
#endif /* IDE_DRIVER */
	struct buffer_head * bh;
	int nsect;

	req->errors = 0;
	if (!uptodate) {
		printk("end_request: I/O error, dev %s, sector %lu\n",
			kdevname(req->rq_dev), req->sector);
#ifdef MACH
		for (bh = req->bh; bh; )
		  {
		    struct buffer_head *next = bh->b_reqnext;
		    bh->b_reqnext = NULL;
		    mark_buffer_uptodate (bh, 0);
		    unlock_buffer (bh);
		    bh = next;
		  }
		req->bh = NULL;
#else
		if ((bh = req->bh) != NULL) {
			nsect = bh->b_size >> 9;
			req->nr_sectors--;
			req->nr_sectors &= ~(nsect - 1);
			req->sector += nsect;
			req->sector &= ~(nsect - 1);
		}
#endif
	}

	if ((bh = req->bh) != NULL) {
		req->bh = bh->b_reqnext;
		bh->b_reqnext = NULL;

 		/*
 		 * This is our 'MD IO has finished' event handler.
 		 * note that b_state should be cached in a register
 		 * anyways, so the overhead if this checking is almost
 		 * zero. But anyways .. we never get OO for free :)
 		 */
 		if (test_bit(BH_MD, &bh->b_state)) {
 			struct md_personality * pers=(struct md_personality *)bh->personality;
 			pers->end_request(bh,uptodate);
 		}
 		/*
 		 * the normal (nonmirrored and no RAID5) case:
 		 */
 		else {
 			mark_buffer_uptodate(bh, uptodate);
 			unlock_buffer(bh);
 		}
		if ((bh = req->bh) != NULL) {
			req->current_nr_sectors = bh->b_size >> 9;
			if (req->nr_sectors < req->current_nr_sectors) {
				req->nr_sectors = req->current_nr_sectors;
				printk("end_request: buffer-list destroyed\n");
			}
			req->buffer = bh->b_data;
			return;
		}
	}
#ifndef DEVICE_NO_RANDOM
	add_blkdev_randomness(MAJOR(req->rq_dev));
#endif
#ifdef IDE_DRIVER
	blk_dev[MAJOR(req->rq_dev)].current_request = req->next;
	hwgroup->rq = NULL;
#else
	DEVICE_OFF(req->rq_dev);
	CURRENT = req->next;
#endif /* IDE_DRIVER */
	if (req->sem != NULL)
		up(req->sem);
	req->rq_status = RQ_INACTIVE;
	wake_up(&wait_for_request);
}
#endif /* defined(IDE_DRIVER) && !defined(_IDE_C) */
#endif /* ! SCSI_BLK_MAJOR(MAJOR_NR) */
#endif /* (MAJOR_NR != SCSI_TAPE_MAJOR) */

#endif /* defined(MAJOR_NR) || defined(IDE_DRIVER) */

#endif /* _BLK_H */