drivers/scsi/scsi_pc98.c

   1 /*
   2  *  Copyright (C) 2003  Osamu Tomita <tomita@cinet.co.jp>
   3  *
   4  *  PC9801 BIOS geometry handling.
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/fs.h>
   9 #include <linux/kernel.h>
  10 #include <linux/genhd.h>
  11 #include <linux/blkdev.h>
  12 #include <asm/pc9800.h>
  13
  14 #include "scsi.h"
  15 #include "hosts.h"
  16
  17
  18 static int pc98_first_bios_param(struct scsi_device *sdev, int *ip)
  19 {
  20         const u8 *p = (&__PC9800SCA(u8, PC9800SCA_SCSI_PARAMS) + sdev->id * 4);
  21
  22         ip[0] = p[1];   /* # of heads */
  23         ip[1] = p[0];   /* # of sectors/track */
  24         ip[2] = *(u16 *)&p[2] & 0x0fff; /* # of cylinders */
  25         if (p[3] & (1 << 6)) { /* #-of-cylinders is 16-bit */
  26                 ip[2] |= (ip[0] & 0xf0) << 8;
  27                 ip[0] &= 0x0f;
  28         }
  29
  30         return 0;
  31 }
  32
  33 int pc98_bios_param(struct scsi_device *sdev, struct block_device *bdev,
  34                         sector_t capacity, int *ip)
  35 {
  36         struct Scsi_Host *first_real = first_real_host();
  37
  38         /*
  39          * XXX
  40          * XXX This needs to become a sysfs attribute that's set
  41          * XXX by code that knows which host is the first one.
  42          * XXX
  43          * XXX Currently we support only one host on with a
  44          * XXX PC98ish HBA.
  45          * XXX
  46          */
  47         if (1 || sdev->host == first_real && sdev->id < 7 &&
  48             __PC9800SCA_TEST_BIT(PC9800SCA_DISK_EQUIPS, sdev->id))
  49                 return pc98_first_bios_param(sdev, ip);
  50
  51         /* Assume PC-9801-92 compatible parameters for HAs without BIOS.  */
  52         ip[0] = 8;
  53         ip[1] = 32;
  54         ip[2] = capacity / (8 * 32);
  55         if (ip[2] > 65535) {    /* if capacity >= 8GB */
  56                 /* Recent on-board adapters seem to use this parameter. */
  57                 ip[1] = 128;
  58                 ip[2] = capacity / (8 * 128);
  59                 if (ip[2] > 65535) { /* if capacity >= 32GB  */
  60                         /* Clip the number of cylinders.  Currently
  61                            this is the limit that we deal with.  */
  62                         ip[2] = 65535;
  63                 }
  64         }
  65
  66         return 0;
  67 }
  68
  69 EXPORT_SYMBOL(pc98_bios_param);