fs/partitions/sun.c

   1 /*
   2  *  fs/partitions/sun.c
   3  *
   4  *  Code extracted from drivers/block/genhd.c
   5  *
   6  *  Copyright (C) 1991-1998  Linus Torvalds
   7  *  Re-organised Feb 1998 Russell King
   8  */
   9
  10 #include <linux/config.h>
  11 #include <linux/fs.h>
  12 #include <linux/genhd.h>
  13 #include <linux/kernel.h>
  14 #include <linux/major.h>
  15 #include <linux/string.h>
  16 #include <linux/blk.h>
  17
  18 #include <asm/system.h>
  19
  20 #include "check.h"
  21 #include "sun.h"
  22
  23 #ifdef CONFIG_BLK_DEV_MD
  24 extern void md_autodetect_dev(kdev_t dev);
  25 #endif
  26
  27 int sun_partition(struct gendisk *hd, struct block_device *bdev, unsigned long first_sector, int first_part_minor)
  28 {
  29         int i, csum;
  30         unsigned short *ush;
  31         Sector sect;
  32         kdev_t dev = to_kdev_t(bdev->bd_dev);
  33         struct sun_disklabel {
  34                 unsigned char info[128];   /* Informative text string */
  35                 unsigned char spare0[14];
  36                 struct sun_info {
  37                         unsigned char spare1;
  38                         unsigned char id;
  39                         unsigned char spare2;
  40                         unsigned char flags;
  41                 } infos[8];
  42                 unsigned char spare[246];  /* Boot information etc. */
  43                 unsigned short rspeed;     /* Disk rotational speed */
  44                 unsigned short pcylcount;  /* Physical cylinder count */
  45                 unsigned short sparecyl;   /* extra sects per cylinder */
  46                 unsigned char spare2[4];   /* More magic... */
  47                 unsigned short ilfact;     /* Interleave factor */
  48                 unsigned short ncyl;       /* Data cylinder count */
  49                 unsigned short nacyl;      /* Alt. cylinder count */
  50                 unsigned short ntrks;      /* Tracks per cylinder */
  51                 unsigned short nsect;      /* Sectors per track */
  52                 unsigned char spare3[4];   /* Even more magic... */
  53                 struct sun_partition {
  54                         __u32 start_cylinder;
  55                         __u32 num_sectors;
  56                 } partitions[8];
  57                 unsigned short magic;      /* Magic number */
  58                 unsigned short csum;       /* Label xor'd checksum */
  59         } * label;
  60         struct sun_partition *p;
  61         unsigned long spc;
  62
  63         label = (struct sun_disklabel *)read_dev_sector(bdev, 0, &sect);
  64         if (!label)
  65                 return -1;
  66
  67         p = label->partitions;
  68         if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
  69 /*              printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
  70                        bdevname(dev), be16_to_cpu(label->magic)); */
  71                 put_dev_sector(sect);
  72                 return 0;
  73         }
  74         /* Look at the checksum */
  75         ush = ((unsigned short *) (label+1)) - 1;
  76         for (csum = 0; ush >= ((unsigned short *) label);)
  77                 csum ^= *ush--;
  78         if (csum) {
  79                 printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
  80                        bdevname(dev));
  81                 put_dev_sector(sect);
  82                 return 0;
  83         }
  84
  85         /* All Sun disks have 8 partition entries */
  86         spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
  87         for (i = 0; i < 8; i++, p++) {
  88                 unsigned long st_sector;
  89                 unsigned int num_sectors;
  90
  91                 st_sector = first_sector + be32_to_cpu(p->start_cylinder) * spc;
  92                 num_sectors = be32_to_cpu(p->num_sectors);
  93                 if (num_sectors) {
  94                         add_gd_partition(hd, first_part_minor,
  95                                          st_sector, num_sectors);
  96 #ifdef CONFIG_BLK_DEV_MD
  97                         if (label->infos[i].id == LINUX_RAID_PARTITION)
  98                                 md_autodetect_dev(MKDEV(hd->major,
  99                                                         first_part_minor));
 100 #endif
 101                 }
 102                 first_part_minor++;
 103         }
 104         printk("\n");
 105         put_dev_sector(sect);
 106         return 1;
 107 }