blob: b87d03903448e3fa76a6bb4ca33b23808ee51259 [file] [log] [blame]
/*
* Copyright (C) 2003 Osamu Tomita <tomita@cinet.co.jp>
*
* PC9801 BIOS geometry handling.
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/genhd.h>
#include <linux/blk.h>
#include <asm/pc9800.h>
#include "scsi.h"
#include "hosts.h"
/* XXX - For now, we assume the first (i.e. having the least host_no)
real (i.e. non-emulated) host adapter shall be BIOS-controlled one.
We *SHOULD* invent another way. */
static inline struct Scsi_Host *first_real_host(void)
{
struct Scsi_Host *shost = NULL;
while ((shost = scsi_host_get_next(shost))) {
if (!shost->hostt->emulated)
break;
}
return shost;
}
static int pc98_first_bios_param(struct scsi_device *sdev, int *ip)
{
const u8 *p = (&__PC9800SCA(u8, PC9800SCA_SCSI_PARAMS) + sdev->id * 4);
ip[0] = p[1]; /* # of heads */
ip[1] = p[0]; /* # of sectors/track */
ip[2] = *(u16 *)&p[2] & 0x0fff; /* # of cylinders */
if (p[3] & (1 << 6)) { /* #-of-cylinders is 16-bit */
ip[2] |= (ip[0] & 0xf0) << 8;
ip[0] &= 0x0f;
}
return 0;
}
int pc98_bios_param(struct scsi_device *sdev, struct block_device *bdev,
sector_t capacity, int *ip)
{
struct Scsi_Host *first_real = first_real_host();
if (sdev->host == first_real && sdev->id < 7 &&
__PC9800SCA_TEST_BIT(PC9800SCA_DISK_EQUIPS, sdev->id))
return pc98_first_bios_param(sdev, ip);
/* Assume PC-9801-92 compatible parameters for HAs without BIOS. */
ip[0] = 8;
ip[1] = 32;
ip[2] = capacity / (8 * 32);
if (ip[2] > 65535) { /* if capacity >= 8GB */
/* Recent on-board adapters seem to use this parameter. */
ip[1] = 128;
ip[2] = capacity / (8 * 128);
if (ip[2] > 65535) { /* if capacity >= 32GB */
/* Clip the number of cylinders. Currently
this is the limit that we deal with. */
ip[2] = 65535;
}
}
return 0;
}
EXPORT_SYMBOL(pc98_bios_param);