path: root/drivers/ide/ide-disk.c

/*
 *  Copyright (C) 1994-1998	   Linus Torvalds & authors (see below)
 *  Copyright (C) 1998-2002	   Linux ATA Development
 *				      Andre Hedrick <andre@linux-ide.org>
 *  Copyright (C) 2003		   Red Hat
 *  Copyright (C) 2003-2005, 2007  Bartlomiej Zolnierkiewicz
 */

/*
 *  Mostly written by Mark Lord <mlord@pobox.com>
 *                and Gadi Oxman <gadio@netvision.net.il>
 *                and Andre Hedrick <andre@linux-ide.org>
 *
 * This is the IDE/ATA disk driver, as evolved from hd.c and ide.c.
 */

#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/leds.h>
#include <linux/ide.h>

#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/div64.h>

#include "ide-disk.h"

static const u8 ide_rw_cmds[] = {
	ATA_CMD_READ_MULTI,
	ATA_CMD_WRITE_MULTI,
	ATA_CMD_READ_MULTI_EXT,
	ATA_CMD_WRITE_MULTI_EXT,
	ATA_CMD_PIO_READ,
	ATA_CMD_PIO_WRITE,
	ATA_CMD_PIO_READ_EXT,
	ATA_CMD_PIO_WRITE_EXT,
	ATA_CMD_READ,
	ATA_CMD_WRITE,
	ATA_CMD_READ_EXT,
	ATA_CMD_WRITE_EXT,
};

static void ide_tf_set_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 dma)
{
	u8 index, lba48, write;

	lba48 = (cmd->tf_flags & IDE_TFLAG_LBA48) ? 2 : 0;
	write = (cmd->tf_flags & IDE_TFLAG_WRITE) ? 1 : 0;

	if (dma) {
		cmd->protocol = ATA_PROT_DMA;
		index = 8;
	} else {
		cmd->protocol = ATA_PROT_PIO;
		if (drive->mult_count) {
			cmd->tf_flags |= IDE_TFLAG_MULTI_PIO;
			index = 0;
		} else
			index = 4;
	}

	cmd->tf.command = ide_rw_cmds[index + lba48 + write];
}

/*
 * __ide_do_rw_disk() issues READ and WRITE commands to a disk,
 * using LBA if supported, or CHS otherwise, to address sectors.
 */
static ide_startstop_t __ide_do_rw_disk(ide_drive_t *drive, struct request *rq,
					sector_t block)
{
	ide_hwif_t *hwif	= drive->hwif;
	u16 nsectors		= (u16)blk_rq_sectors(rq);
	u8 lba48		= !!(drive->dev_flags & IDE_DFLAG_LBA48);
	u8 dma			= !!(drive->dev_flags & IDE_DFLAG_USING_DMA);
	struct ide_cmd		cmd;
	struct ide_taskfile	*tf = &cmd.tf;
	ide_startstop_t		rc;

	if ((hwif->host_flags & IDE_HFLAG_NO_LBA48_DMA) && lba48 && dma) {
		if (block + blk_rq_sectors(rq) > 1ULL << 28)
			dma = 0;
		else
			lba48 = 0;
	}

	memset(&cmd, 0, sizeof(cmd));
	cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE;
	cmd.valid.in.tf  = IDE_VALID_IN_TF  | IDE_VALID_DEVICE;

	if (drive->dev_flags & IDE_DFLAG_LBA) {
		if (lba48) {
			pr_debug("%s: LBA=0x%012llx\n", drive->name,
					(unsigned long long)block);

			tf->nsect  = nsectors & 0xff;
			tf->lbal   = (u8) block;
			tf->lbam   = (u8)(block >>  8);
			tf->lbah   = (u8)(block >> 16);
			tf->device = ATA_LBA;

			tf = &cmd.hob;
			tf->nsect = (nsectors >> 8) & 0xff;
			tf->lbal  = (u8)(block >> 24);
			if (sizeof(block) != 4) {
				tf->lbam = (u8)((u64)block >> 32);
				tf->lbah = (u8)((u64)block >> 40);
			}

			cmd.valid.out.hob = IDE_VALID_OUT_HOB;
			cmd.valid.in.hob  = IDE_VALID_IN_HOB;
			cmd.tf_flags |= IDE_TFLAG_LBA48;
		} else {
			tf->nsect  = nsectors & 0xff;
			tf->lbal   = block;
			tf->lbam   = block >>= 8;
			tf->lbah   = block >>= 8;
			tf->device = ((block >> 8) & 0xf) | ATA_LBA;
		}
	} else {
		unsigned int sect, head, cyl, track;

		track = (int)block / drive->sect;
		sect  = (int)block % drive->sect + 1;
		head  = track % drive->head;
		cyl   = track / drive->head;

		pr_debug("%s: CHS=%u/%u/%u\n", drive->name, cyl, head, sect);

		tf->nsect  = nsectors & 0xff;
		tf->lbal   = sect;
		tf->lbam   = cyl;
		tf->lbah   = cyl >> 8;
		tf->device = head;
	}

	cmd.tf_flags |= IDE_TFLAG_FS;

	if (rq_data_dir(rq))
		cmd.tf_flags |= IDE_TFLAG_WRITE;

	ide_tf_set_cmd(drive, &cmd, dma);
	cmd.rq = rq;

	if (dma == 0) {
		ide_init_sg_cmd(&cmd, nsectors << 9);
		ide_map_sg(drive, &cmd);
	}

	rc = do_rw_taskfile(drive, &cmd);

	if (rc == ide_stopped