ide.c

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

		if (nsect > mcount)
			nsect = mcount;
		mcount -= nsect;

		ide_output_data(drive, rq->buffer, nsect<<7);
#ifdef DEBUG
		printk("%s: multwrite: sector %ld, buffer=0x%08lx, count=%d, remaining=%ld\n",
			drive->name, rq->sector, (unsigned long) rq->buffer,
			nsect, rq->nr_sectors - nsect);
#endif
		if ((rq->nr_sectors -= nsect) <= 0)
			break;
		if ((rq->current_nr_sectors -= nsect) == 0) {
			if ((rq->bh = rq->bh->b_reqnext) != NULL) {
				rq->current_nr_sectors = rq->bh->b_size>>9;
				rq->buffer             = rq->bh->b_data;
			} else {
				panic("%s: buffer list corrupted\n", drive->name);
				break;
			}
		} else {
			rq->buffer += nsect << 9;
		}
	} while (mcount);
}

/*
 * multwrite_intr() is the handler for disk multwrite interrupts
 */
static void multwrite_intr (ide_drive_t *drive)
{
	byte stat;
	int i;
	ide_hwgroup_t *hwgroup = HWGROUP(drive);
	struct request *rq = &hwgroup->wrq;

	if (OK_STAT(stat=GET_STAT(),DRIVE_READY,drive->bad_wstat)) {
		if (stat & DRQ_STAT) {
			if (rq->nr_sectors) {
				ide_multwrite(drive, drive->mult_count);
				ide_set_handler (drive, &multwrite_intr, WAIT_CMD);
				return;
			}
		} else {
			if (!rq->nr_sectors) {	/* all done? */
				rq = hwgroup->rq;
				for (i = rq->nr_sectors; i > 0;){
					i -= rq->current_nr_sectors;
					ide_end_request(1, hwgroup);
				}
				return;
			}
		}
	}
	ide_error(drive, "multwrite_intr", stat);
}

/*
 * Issue a simple drive command
 * The drive must be selected beforehand.
 */
static void ide_cmd(ide_drive_t *drive, byte cmd, byte nsect, ide_handler_t *handler)
{
	ide_set_handler (drive, handler, WAIT_CMD);
	OUT_BYTE(drive->ctl,IDE_CONTROL_REG);
	OUT_BYTE(nsect,IDE_NSECTOR_REG);
	OUT_BYTE(cmd,IDE_COMMAND_REG);
}

/*
 * set_multmode_intr() is invoked on completion of a WIN_SETMULT cmd.
 */
static void set_multmode_intr (ide_drive_t *drive)
{
	byte stat = GET_STAT();

	sti();
	if (OK_STAT(stat,READY_STAT,BAD_STAT)) {
		drive->mult_count = drive->mult_req;
	} else {
		drive->mult_req = drive->mult_count = 0;
		drive->special.b.recalibrate = 1;
		(void) ide_dump_status(drive, "set_multmode", stat);
	}
}

/*
 * set_geometry_intr() is invoked on completion of a WIN_SPECIFY cmd.
 */
static void set_geometry_intr (ide_drive_t *drive)
{
	byte stat = GET_STAT();

	sti();
	if (!OK_STAT(stat,READY_STAT,BAD_STAT))
		ide_error(drive, "set_geometry_intr", stat);
}

/*
 * recal_intr() is invoked on completion of a WIN_RESTORE (recalibrate) cmd.
 */
static void recal_intr (ide_drive_t *drive)
{
	byte stat = GET_STAT();

	sti();
	if (!OK_STAT(stat,READY_STAT,BAD_STAT))
		ide_error(drive, "recal_intr", stat);
}

/*
 * mc_intr() is invoked on completion of a WIN_ACKMC cmd.
 */
static void mc_intr (ide_drive_t *drive)
{
	byte stat = GET_STAT();

	sti();
	if (!OK_STAT(stat,READY_STAT,BAD_STAT))
		ide_error(drive, "mc_intr", stat);
	drive->special.b.mc = 0;
}

/*
 * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
 */
static void drive_cmd_intr (ide_drive_t *drive)
{
	struct request *rq = HWGROUP(drive)->rq;
	byte *args = (byte *) rq->buffer;
	byte stat = GET_STAT();

	sti();
	if ((stat & DRQ_STAT) && args && args[3]) {
		byte io_32bit = drive->io_32bit;
		drive->io_32bit = 0;
		ide_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
		drive->io_32bit = io_32bit;
		stat = GET_STAT();
	}
	if (OK_STAT(stat,READY_STAT,BAD_STAT))
		ide_end_drive_cmd (drive, stat, GET_ERR());
	else
		ide_error(drive, "drive_cmd", stat); /* calls ide_end_drive_cmd */
}

/*
 * do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
 * commands to a drive.  It used to do much more, but has been scaled back.
 */
static inline void do_special (ide_drive_t *drive)
{
	special_t *s = &drive->special;

#ifdef DEBUG
	printk("%s: do_special: 0x%02x\n", drive->name, s->all);
#endif
	if (s->b.set_geometry) {
		s->b.set_geometry = 0;
		if (drive->media == ide_disk && !drive->no_geom) {
			OUT_BYTE(drive->sect,IDE_SECTOR_REG);
			OUT_BYTE(drive->cyl,IDE_LCYL_REG);
			OUT_BYTE(drive->cyl>>8,IDE_HCYL_REG);
			OUT_BYTE(((drive->head-1)|drive->select.all)&0xBF,IDE_SELECT_REG);
			if (!IS_PROMISE_DRIVE)
				ide_cmd(drive, WIN_SPECIFY, drive->sect, &set_geometry_intr);
		}
	} else if (s->b.recalibrate) {
		s->b.recalibrate = 0;
		if (drive->media == ide_disk && !IS_PROMISE_DRIVE)
			ide_cmd(drive, WIN_RESTORE, drive->sect, &recal_intr);
	} else if (s->b.set_tune) {
		ide_tuneproc_t *tuneproc = HWIF(drive)->tuneproc;
		s->b.set_tune = 0;
		if (tuneproc != NULL)
			tuneproc(drive, drive->tune_req);
	} else if (s->b.set_multmode) {
		s->b.set_multmode = 0;
		if (drive->media == ide_disk) {
			if (drive->id && drive->mult_req > drive->id->max_multsect)
				drive->mult_req = drive->id->max_multsect;
			if (!IS_PROMISE_DRIVE)
				ide_cmd(drive, WIN_SETMULT, drive->mult_req, &set_multmode_intr);
		} else
			drive->mult_req = 0;
	} else if (s->b.mc) {
		s->b.mc = 0;
		if (drive->media == ide_disk && !IS_PROMISE_DRIVE)
			ide_cmd(drive, WIN_ACKMC, drive->sect, &mc_intr);
	} else if (s->all) {
		int special = s->all;
		s->all = 0;
		printk("%s: bad special flag: 0x%02x\n", drive->name, special);
	}
}

/*
 * This routine busy-waits for the drive status to be not "busy".
 * It then checks the status for all of the "good" bits and none
 * of the "bad" bits, and if all is okay it returns 0.  All other
 * cases return 1 after invoking ide_error() -- caller should just return.
 *
 * This routine should get fixed to not hog the cpu during extra long waits..
 * That could be done by busy-waiting for the first jiffy or two, and then
 * setting a timer to wake up at half second intervals thereafter,
 * until timeout is achieved, before timing out.
 */
int ide_wait_stat (ide_drive_t *drive, byte good, byte bad, unsigned long timeout)
{
	byte stat;
	unsigned long flags;

	udelay(1);	/* spec allows drive 400ns to assert "BUSY" */
	if ((stat = GET_STAT()) & BUSY_STAT) {
		save_flags(flags);
		sti();
		timeout += jiffies;
		while ((stat = GET_STAT()) & BUSY_STAT) {
			if (jiffies > timeout) {
				restore_flags(flags);
				ide_error(drive, "status timeout", stat);
				return 1;
			}
		}
		restore_flags(flags);
	}
	udelay(1);	/* allow status to settle, then read it again */
	if (OK_STAT((stat = GET_STAT()), good, bad))
		return 0;
	ide_error(drive, "status error", stat);
	return 1;
}

/*
 * do_rw_disk() issues READ and WRITE commands to a disk,
 * using LBA if supported, or CHS otherwise, to address sectors.
 * It also takes care of issuing special DRIVE_CMDs.
 */
static inline void do_rw_disk (ide_drive_t *drive, struct request *rq, unsigned long block)
{
	ide_hwif_t *hwif = HWIF(drive);
	unsigned short io_base = hwif->io_base;
#ifdef CONFIG_BLK_DEV_PROMISE
	int use_promise_io = 0;
#endif /* CONFIG_BLK_DEV_PROMISE */

	OUT_BYTE(drive->ctl,IDE_CONTROL_REG);
	OUT_BYTE(rq->nr_sectors,io_base+IDE_NSECTOR_OFFSET);
#ifdef CONFIG_BLK_DEV_PROMISE
	if (IS_PROMISE_DRIVE) {
		if (hwif->is_promise2 || rq->cmd == READ) {
			use_promise_io = 1;
		}
	}
	if (drive->select.b.lba || use_promise_io) {
#else /* !CONFIG_BLK_DEV_PROMISE */
	if (drive->select.b.lba) {
#endif /* CONFIG_BLK_DEV_PROMISE */
#ifdef DEBUG
		printk("%s: %sing: LBAsect=%ld, sectors=%ld, buffer=0x%08lx\n",
			drive->name, (rq->cmd==READ)?"read":"writ",
			block, rq->nr_sectors, (unsigned long) rq->buffer);
#endif
		OUT_BYTE(block,io_base+IDE_SECTOR_OFFSET);
		OUT_BYTE(block>>=8,io_base+IDE_LCYL_OFFSET);
		OUT_BYTE(block>>=8,io_base+IDE_HCYL_OFFSET);
		OUT_BYTE(((block>>8)&0x0f)|drive->select.all,io_base+IDE_SELECT_OFFSET);
	} else {
		unsigned int sect,head,cyl,track;
		track = block / drive->sect;
		sect  = block % drive->sect + 1;
		OUT_BYTE(sect,io_base+IDE_SECTOR_OFFSET);
		head  = track % drive->head;
		cyl   = track / drive->head;
		OUT_BYTE(cyl,io_base+IDE_LCYL_OFFSET);
		OUT_BYTE(cyl>>8,io_base+IDE_HCYL_OFFSET);
		OUT_BYTE(head|drive->select.all,io_base+IDE_SELECT_OFFSET);
#ifdef DEBUG
		printk("%s: %sing: CHS=%d/%d/%d, sectors=%ld, buffer=0x%08lx\n",
			drive->name, (rq->cmd==READ)?"read":"writ", cyl,
			head, sect, rq->nr_sectors, (unsigned long) rq->buffer);
#endif
	}
#ifdef CONFIG_BLK_DEV_PROMISE
	if (use_promise_io) {
		do_promise_io (drive, rq);
		return;
	}
#endif /* CONFIG_BLK_DEV_PROMISE */
	if (rq->cmd == READ) {
#ifdef CONFIG_BLK_DEV_TRITON
		if (drive->using_dma && !(HWIF(drive)->dmaproc(ide_dma_read, drive)))
			return;
#endif /* CONFIG_BLK_DEV_TRITON */
		ide_set_handler(drive, &read_intr, WAIT_CMD);
		OUT_BYTE(drive->mult_count ? WIN_MULTREAD : WIN_READ, io_base+IDE_COMMAND_OFFSET);
		return;
	}
	if (rq->cmd == WRITE) {
#ifdef CONFIG_BLK_DEV_TRITON
		if (drive->using_dma && !(HWIF(drive)->dmaproc(ide_dma_write, drive)))
			return;
#endif /* CONFIG_BLK_DEV_TRITON */
		OUT_BYTE(drive->mult_count ? WIN_MULTWRITE : WIN_WRITE, io_base+IDE_COMMAND_OFFSET);
		if (ide_wait_stat(drive, DATA_READY, drive->bad_wstat, WAIT_DRQ)) {
			printk("%s: no DRQ after issuing %s\n", drive->name,
				drive->mult_count ? "MULTWRITE" : "WRITE");
			return;
		}
		if (!drive->unmask)
			cli();
		if (drive->mult_count) {
			HWGROUP(drive)->wrq = *rq; /* scratchpad */
			ide_set_handler (drive, &multwrite_intr, WAIT_CMD);
			ide_multwrite(drive, drive->mult_count);
		} else {
			ide_set_handler (drive, &write_intr, WAIT_CMD);
			ide_output_data(drive, rq->buffer, SECTOR_WORDS);
		}
		return;
	}
	printk("%s: bad command: %d\n", drive->name, rq->cmd);
	ide_end_request(0, HWGROUP(drive));
}

/*
 * execute_drive_cmd() issues a special drive command,
 * usually initiated by ioctl() from the external hdparm program.
 */
static void execute_drive_cmd (ide_drive_t *drive, struct request *rq)
{
	byte *args = rq->buffer;
	if (args) {
#ifdef DEBUG
		printk("%s: DRIVE_CMD cmd=0x%02x sc=0x%02x fr=0x%02x xx=0x%02x\n",
		 drive->name, args[0], args[1], args[2], args[3]);
#endif
		OUT_BYTE(args[2],IDE_FEATURE_REG);
		ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
		return;
	} else {
		/*
		 * NULL is actually a valid way of waiting for
		 * all current requests to be flushed from the queue.
		 */
#ifdef DEBUG
		printk("%s: DRIVE_CMD (null)\n", drive->name);
#endif
		ide_end_drive_cmd(drive, GET_STAT(), GET_ERR());
		return;
	}
}

/*
 * do_request() initiates handling of a new I/O request
 */
static inline void do_request (ide_hwif_t *hwif, struct request *rq)
{
	unsigned int minor, unit;
	unsigned long block, blockend;
	ide_drive_t *drive;

	sti();
#ifdef DEBUG
	printk("%s: do_request: current=0x%08lx\n", hwif->name, (unsigned long) rq);
#endif
	minor = MINOR(rq->rq_dev);
	unit = minor >> PARTN_BITS;
	if (MAJOR(rq->rq_dev) != hwif->major || unit >= MAX_DRIVES) {
		printk("%s: bad device number: %s\n",
		       hwif->name, kdevname(rq->rq_dev));
		goto kill_rq;
	}
	drive = &hwif->drives[unit];
#ifdef DEBUG
	if (rq->bh && !buffer_locked(rq->bh)) {
		printk("%s: block not locked\n", drive->name);
		goto kill_rq;
	}
#endif
	block    = rq->sector;
	blockend = block + rq->nr_sectors;
	if ((blockend < block) || (blockend > drive->part[minor&PARTN_MASK].nr_sects)) {
#ifdef MACH
	  printk ("%s%c: bad access: block=%ld, count=%ld, blockend=%ld, nr_sects%ld\n",
		  drive->name, (minor&PARTN_MASK)?'0'+(minor&PARTN_MASK):' ',
		  block, rq->nr_sectors, blockend, drive->part[minor&PARTN_MASK].nr_sects);
#else
		printk("%s%c: bad access: block=%ld, count=%ld\n", drive->name,
		 (minor&PARTN_MASK)?'0'+(minor&PARTN_MASK):' ', block, rq->nr_sectors);
#endif
		goto kill_rq;
	}
	block += drive->part[minor&PARTN_MASK].start_sect + drive->sect0;
#if FAKE_FDISK_FOR_EZDRIVE
	if (block == 0 && drive->remap_0_to_1)
		block = 1;  /* redirect MBR access to EZ-Drive partn table */
#endif /* FAKE_FDISK_FOR_EZDRIVE */