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 38 for (blk = 0; ; blk++, put_dev_sector(sect)) { 39 if (blk == RDB_ALLOCATION_LIMIT) 40 goto rdb_done; 41 data = read_part_sector(state, blk, §); 42 if (!data) { 43 pr_err("Dev %s: unable to read RDB block %d\n", 44 state->disk->disk_name, blk); 45 res = -1; 46 goto rdb_done; 47 } 48 if (*(__be32 *)data != cpu_to_be32(IDNAME_RIGIDDISK)) 49 continue; 50 51 rdb = (struct RigidDiskBlock *)data; 52 if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0) 53 break; 54 /* Try again with 0xdc..0xdf zeroed, Windows might have 55 * trashed it. 56 */ 57 *(__be32 *)(data+0xdc) = 0; 58 if (checksum_block((__be32 *)data, 59 be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) { 60 pr_err("Trashed word at 0xd0 in block %d ignored in checksum calculation\n", 61 blk); 62 break; 63 } 64 65 pr_err("Dev %s: RDB in block %d has bad checksum\n", 66 state->disk->disk_name, blk); 67 } 68 69 /* blksize is blocks per 512 byte standard block */ 70 blksize = be32_to_cpu( rdb->rdb_BlockBytes ) / 512; 71 72 { 73 char tmp[7 + 10 + 1 + 1]; 74 75 /* Be more informative */ 76 snprintf(tmp, sizeof(tmp), " RDSK (%d)", blksize * 512); 77 strlcat(state->pp_buf, tmp, PAGE_SIZE); 78 } 79 blk = be32_to_cpu(rdb->rdb_PartitionList); 80 put_dev_sector(sect); 81 for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) { 82 blk *= blksize; /* Read in terms partition table understands */ 83 data = read_part_sector(state, blk, §); 84 if (!data) { 85 pr_err("Dev %s: unable to read partition block %d\n", 86 state->disk->disk_name, blk); 87 res = -1; 88 goto rdb_done; 89 } 90 pb = (struct PartitionBlock *)data; 91 blk = be32_to_cpu(pb->pb_Next); 92 if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION)) 93 continue; 94 if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 ) 95 continue; 96 97 /* Tell Kernel about it */ 98 99 nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 - 100 be32_to_cpu(pb->pb_Environment[9])) * 101 be32_to_cpu(pb->pb_Environment[3]) * 102 be32_to_cpu(pb->pb_Environment[5]) * 103 blksize; 104 if (!nr_sects) 105 continue; 106 start_sect = be32_to_cpu(pb->pb_Environment[9]) * 107 be32_to_cpu(pb->pb_Environment[3]) * 108 be32_to_cpu(pb->pb_Environment[5]) * 109 blksize; 110 put_partition(state,slot++,start_sect,nr_sects); 111 { 112 /* Be even more informative to aid mounting */ 113 char dostype[4]; 114 char tmp[42]; 115 116 __be32 *dt = (__be32 *)dostype; 117 *dt = pb->pb_Environment[16]; 118 if (dostype[3] < ' ') 119 snprintf(tmp, sizeof(tmp), " (%c%c%c^%c)", 120 dostype[0], dostype[1], 121 dostype[2], dostype[3] + '@' ); 122 else 123 snprintf(tmp, sizeof(tmp), " (%c%c%c%c)", 124 dostype[0], dostype[1], 125 dostype[2], dostype[3]); 126 strlcat(state->pp_buf, tmp, PAGE_SIZE); 127 snprintf(tmp, sizeof(tmp), "(res %d spb %d)", 128 be32_to_cpu(pb->pb_Environment[6]), 129 be32_to_cpu(pb->pb_Environment[4])); 130 strlcat(state->pp_buf, tmp, PAGE_SIZE); 131 } 132 res = 1; 133 } 134 strlcat(state->pp_buf, "\n", PAGE_SIZE); 135 136 rdb_done: 137 return res; 138 } 139