Michael Holzheu | 4857d4b | 2012-03-11 11:59:34 -0400 | [diff] [blame] | 1 | /* |
| 2 | * OS info memory interface |
| 3 | * |
| 4 | * Copyright IBM Corp. 2012 |
| 5 | * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com> |
| 6 | */ |
| 7 | |
| 8 | #define KMSG_COMPONENT "os_info" |
| 9 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
| 10 | |
| 11 | #include <linux/crash_dump.h> |
| 12 | #include <linux/kernel.h> |
David Howells | 0d01ff2 | 2013-04-11 23:51:01 +0100 | [diff] [blame] | 13 | #include <linux/slab.h> |
Michael Holzheu | 4857d4b | 2012-03-11 11:59:34 -0400 | [diff] [blame] | 14 | #include <asm/checksum.h> |
| 15 | #include <asm/lowcore.h> |
Michael Holzheu | 4857d4b | 2012-03-11 11:59:34 -0400 | [diff] [blame] | 16 | #include <asm/os_info.h> |
| 17 | |
| 18 | /* |
| 19 | * OS info structure has to be page aligned |
| 20 | */ |
| 21 | static struct os_info os_info __page_aligned_data; |
| 22 | |
| 23 | /* |
| 24 | * Compute checksum over OS info structure |
| 25 | */ |
| 26 | u32 os_info_csum(struct os_info *os_info) |
| 27 | { |
| 28 | int size = sizeof(*os_info) - offsetof(struct os_info, version_major); |
| 29 | return csum_partial(&os_info->version_major, size, 0); |
| 30 | } |
| 31 | |
| 32 | /* |
| 33 | * Add crashkernel info to OS info and update checksum |
| 34 | */ |
| 35 | void os_info_crashkernel_add(unsigned long base, unsigned long size) |
| 36 | { |
| 37 | os_info.crashkernel_addr = (u64)(unsigned long)base; |
| 38 | os_info.crashkernel_size = (u64)(unsigned long)size; |
| 39 | os_info.csum = os_info_csum(&os_info); |
| 40 | } |
| 41 | |
| 42 | /* |
| 43 | * Add OS info entry and update checksum |
| 44 | */ |
| 45 | void os_info_entry_add(int nr, void *ptr, u64 size) |
| 46 | { |
| 47 | os_info.entry[nr].addr = (u64)(unsigned long)ptr; |
| 48 | os_info.entry[nr].size = size; |
| 49 | os_info.entry[nr].csum = csum_partial(ptr, size, 0); |
| 50 | os_info.csum = os_info_csum(&os_info); |
| 51 | } |
| 52 | |
| 53 | /* |
| 54 | * Initialize OS info struture and set lowcore pointer |
| 55 | */ |
| 56 | void __init os_info_init(void) |
| 57 | { |
| 58 | void *ptr = &os_info; |
| 59 | |
| 60 | os_info.version_major = OS_INFO_VERSION_MAJOR; |
| 61 | os_info.version_minor = OS_INFO_VERSION_MINOR; |
| 62 | os_info.magic = OS_INFO_MAGIC; |
| 63 | os_info.csum = os_info_csum(&os_info); |
Heiko Carstens | fbe7656 | 2012-06-05 09:59:52 +0200 | [diff] [blame] | 64 | mem_assign_absolute(S390_lowcore.os_info, (unsigned long) ptr); |
Michael Holzheu | 4857d4b | 2012-03-11 11:59:34 -0400 | [diff] [blame] | 65 | } |
| 66 | |
| 67 | #ifdef CONFIG_CRASH_DUMP |
| 68 | |
| 69 | static struct os_info *os_info_old; |
| 70 | |
| 71 | /* |
| 72 | * Allocate and copy OS info entry from oldmem |
| 73 | */ |
| 74 | static void os_info_old_alloc(int nr, int align) |
| 75 | { |
| 76 | unsigned long addr, size = 0; |
| 77 | char *buf, *buf_align, *msg; |
| 78 | u32 csum; |
| 79 | |
| 80 | addr = os_info_old->entry[nr].addr; |
| 81 | if (!addr) { |
| 82 | msg = "not available"; |
| 83 | goto fail; |
| 84 | } |
| 85 | size = os_info_old->entry[nr].size; |
| 86 | buf = kmalloc(size + align - 1, GFP_KERNEL); |
| 87 | if (!buf) { |
| 88 | msg = "alloc failed"; |
| 89 | goto fail; |
| 90 | } |
| 91 | buf_align = PTR_ALIGN(buf, align); |
| 92 | if (copy_from_oldmem(buf_align, (void *) addr, size)) { |
| 93 | msg = "copy failed"; |
| 94 | goto fail_free; |
| 95 | } |
| 96 | csum = csum_partial(buf_align, size, 0); |
| 97 | if (csum != os_info_old->entry[nr].csum) { |
| 98 | msg = "checksum failed"; |
| 99 | goto fail_free; |
| 100 | } |
| 101 | os_info_old->entry[nr].addr = (u64)(unsigned long)buf_align; |
| 102 | msg = "copied"; |
| 103 | goto out; |
| 104 | fail_free: |
| 105 | kfree(buf); |
| 106 | fail: |
| 107 | os_info_old->entry[nr].addr = 0; |
| 108 | out: |
| 109 | pr_info("entry %i: %s (addr=0x%lx size=%lu)\n", |
| 110 | nr, msg, addr, size); |
| 111 | } |
| 112 | |
| 113 | /* |
| 114 | * Initialize os info and os info entries from oldmem |
| 115 | */ |
| 116 | static void os_info_old_init(void) |
| 117 | { |
| 118 | static int os_info_init; |
| 119 | unsigned long addr; |
| 120 | |
| 121 | if (os_info_init) |
| 122 | return; |
| 123 | if (!OLDMEM_BASE) |
| 124 | goto fail; |
| 125 | if (copy_from_oldmem(&addr, &S390_lowcore.os_info, sizeof(addr))) |
| 126 | goto fail; |
| 127 | if (addr == 0 || addr % PAGE_SIZE) |
| 128 | goto fail; |
| 129 | os_info_old = kzalloc(sizeof(*os_info_old), GFP_KERNEL); |
| 130 | if (!os_info_old) |
| 131 | goto fail; |
| 132 | if (copy_from_oldmem(os_info_old, (void *) addr, sizeof(*os_info_old))) |
| 133 | goto fail_free; |
| 134 | if (os_info_old->magic != OS_INFO_MAGIC) |
| 135 | goto fail_free; |
| 136 | if (os_info_old->csum != os_info_csum(os_info_old)) |
| 137 | goto fail_free; |
| 138 | if (os_info_old->version_major > OS_INFO_VERSION_MAJOR) |
| 139 | goto fail_free; |
| 140 | os_info_old_alloc(OS_INFO_VMCOREINFO, 1); |
| 141 | os_info_old_alloc(OS_INFO_REIPL_BLOCK, 1); |
Michael Holzheu | 4857d4b | 2012-03-11 11:59:34 -0400 | [diff] [blame] | 142 | pr_info("crashkernel: addr=0x%lx size=%lu\n", |
| 143 | (unsigned long) os_info_old->crashkernel_addr, |
| 144 | (unsigned long) os_info_old->crashkernel_size); |
| 145 | os_info_init = 1; |
| 146 | return; |
| 147 | fail_free: |
| 148 | kfree(os_info_old); |
| 149 | fail: |
| 150 | os_info_init = 1; |
| 151 | os_info_old = NULL; |
| 152 | } |
| 153 | |
| 154 | /* |
| 155 | * Return pointer to os infor entry and its size |
| 156 | */ |
| 157 | void *os_info_old_entry(int nr, unsigned long *size) |
| 158 | { |
| 159 | os_info_old_init(); |
| 160 | |
| 161 | if (!os_info_old) |
| 162 | return NULL; |
| 163 | if (!os_info_old->entry[nr].addr) |
| 164 | return NULL; |
| 165 | *size = (unsigned long) os_info_old->entry[nr].size; |
| 166 | return (void *)(unsigned long)os_info_old->entry[nr].addr; |
| 167 | } |
| 168 | #endif |