1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * fs/partitions/amiga.c 4 * 5 * Code extracted from drivers/block/genhd.c 6 * 7 * Copyright (C) 1991-1998 Linus Torvalds 8 * Re-organised Feb 1998 Russell King 9 */ 10 11 #define pr_fmt(fmt) fmt 12 13 #include <linux/types.h> 14 #include <linux/affs_hardblocks.h> 15 16 #include "check.h" 17 18 static __inline__ u32 19 checksum_block(__be32 *m, int size) 20 { 21 u32 sum = 0; 22 23 while (size--) 24 sum += be32_to_cpu(*m++); 25 return sum; 26 } 27 28 int amiga_partition(struct parsed_partitions *state) 29 { 30 Sector sect; 31 unsigned char *data; 32 struct RigidDiskBlock *rdb; 33 struct PartitionBlock *pb; 34 int start_sect, nr_sects, blk, part, res = 0; 35 int blksize = 1; /* Multiplier for disk block size */ 36 int slot = 1; 37 char b[BDEVNAME_SIZE]; 38 39 for (blk = 0; ; blk++, put_dev_sector(sect)) { 40 if (blk == RDB_ALLOCATION_LIMIT) 41 goto rdb_done; 42 data = read_part_sector(state, blk, §); 43 if (!data) { 44 pr_err("Dev %s: unable to read RDB block %d\n", 45 bdevname(state->bdev, b), blk); 46 res = -1; 47 goto rdb_done; 48 } 49 if (*(__be32 *)data != cpu_to_be32(IDNAME_RIGIDDISK)) 50 continue; 51 52 rdb = (struct RigidDiskBlock *)data; 53 if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0) 54 break; 55 /* Try again with 0xdc..0xdf zeroed, Windows might have 56 * trashed it. 57 */ 58 *(__be32 *)(data+0xdc) = 0; 59 if (checksum_block((__be32 *)data, 60 be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) { 61 pr_err("Trashed word at 0xd0 in block %d ignored in checksum calculation\n", 62 blk); 63 break; 64 } 65 66 pr_err("Dev %s: RDB in block %d has bad checksum\n", 67 bdevname(state->bdev, b), blk); 68 } 69 70 /* blksize is blocks per 512 byte standard block */ 71 blksize = be32_to_cpu( rdb->rdb_BlockBytes ) / 512; 72 73 { 74 char tmp[7 + 10 + 1 + 1]; 75 76 /* Be more informative */ 77 snprintf(tmp, sizeof(tmp), " RDSK (%d)", blksize * 512); 78 strlcat(state->pp_buf, tmp, PAGE_SIZE); 79 } 80 blk = be32_to_cpu(rdb->rdb_PartitionList); 81 put_dev_sector(sect); 82 for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) { 83 blk *= blksize; /* Read in terms partition table understands */ 84 data = read_part_sector(state, blk, §); 85 if (!data) { 86 pr_err("Dev %s: unable to read partition block %d\n", 87 bdevname(state->bdev, b), blk); 88 res = -1; 89 goto rdb_done; 90 } 91 pb = (struct PartitionBlock *)data; 92 blk = be32_to_cpu(pb->pb_Next); 93 if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION)) 94 continue; 95 if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 ) 96 continue; 97 98 /* Tell Kernel about it */ 99 100 nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 - 101 be32_to_cpu(pb->pb_Environment[9])) * 102 be32_to_cpu(pb->pb_Environment[3]) * 103 be32_to_cpu(pb->pb_Environment[5]) * 104 blksize; 105 if (!nr_sects) 106 continue; 107 start_sect = be32_to_cpu(pb->pb_Environment[9]) * 108 be32_to_cpu(pb->pb_Environment[3]) * 109 be32_to_cpu(pb->pb_Environment[5]) * 110 blksize; 111 put_partition(state,slot++,start_sect,nr_sects); 112 { 113 /* Be even more informative to aid mounting */ 114 char dostype[4]; 115 char tmp[42]; 116 117 __be32 *dt = (__be32 *)dostype; 118 *dt = pb->pb_Environment[16]; 119 if (dostype[3] < ' ') 120 snprintf(tmp, sizeof(tmp), " (%c%c%c^%c)", 121 dostype[0], dostype[1], 122 dostype[2], dostype[3] + '@' ); 123 else 124 snprintf(tmp, sizeof(tmp), " (%c%c%c%c)", 125 dostype[0], dostype[1], 126 dostype[2], dostype[3]); 127 strlcat(state->pp_buf, tmp, PAGE_SIZE); 128 snprintf(tmp, sizeof(tmp), "(res %d spb %d)", 129 be32_to_cpu(pb->pb_Environment[6]), 130 be32_to_cpu(pb->pb_Environment[4])); 131 strlcat(state->pp_buf, tmp, PAGE_SIZE); 132 } 133 res = 1; 134 } 135 strlcat(state->pp_buf, "\n", PAGE_SIZE); 136 137 rdb_done: 138 return res; 139 } 140