Ben Dooks | 549c7e3 | 2008-12-12 00:24:07 +0000 | [diff] [blame^] | 1 | /* linux/arch/arm/plat-s3c/pm-check.c |
| 2 | * originally in linux/arch/arm/plat-s3c24xx/pm.c |
| 3 | * |
| 4 | * Copyright (c) 2004,2006,2008 Simtec Electronics |
| 5 | * http://armlinux.simtec.co.uk |
| 6 | * Ben Dooks <ben@simtec.co.uk> |
| 7 | * |
| 8 | * S3C Power Mangament - suspend/resume memory corruptiuon check. |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License version 2 as |
| 12 | * published by the Free Software Foundation. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/suspend.h> |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/crc32.h> |
| 19 | #include <linux/ioport.h> |
| 20 | |
| 21 | #include <plat/pm.h> |
| 22 | |
| 23 | #if CONFIG_S3C2410_PM_CHECK_CHUNKSIZE < 1 |
| 24 | #error CONFIG_S3C2410_PM_CHECK_CHUNKSIZE must be a positive non-zero value |
| 25 | #endif |
| 26 | |
| 27 | /* suspend checking code... |
| 28 | * |
| 29 | * this next area does a set of crc checks over all the installed |
| 30 | * memory, so the system can verify if the resume was ok. |
| 31 | * |
| 32 | * CONFIG_S3C2410_PM_CHECK_CHUNKSIZE defines the block-size for the CRC, |
| 33 | * increasing it will mean that the area corrupted will be less easy to spot, |
| 34 | * and reducing the size will cause the CRC save area to grow |
| 35 | */ |
| 36 | |
| 37 | #define CHECK_CHUNKSIZE (CONFIG_S3C2410_PM_CHECK_CHUNKSIZE * 1024) |
| 38 | |
| 39 | static u32 crc_size; /* size needed for the crc block */ |
| 40 | static u32 *crcs; /* allocated over suspend/resume */ |
| 41 | |
| 42 | typedef u32 *(run_fn_t)(struct resource *ptr, u32 *arg); |
| 43 | |
| 44 | /* s3c_pm_run_res |
| 45 | * |
| 46 | * go through the given resource list, and look for system ram |
| 47 | */ |
| 48 | |
| 49 | static void s3c_pm_run_res(struct resource *ptr, run_fn_t fn, u32 *arg) |
| 50 | { |
| 51 | while (ptr != NULL) { |
| 52 | if (ptr->child != NULL) |
| 53 | s3c_pm_run_res(ptr->child, fn, arg); |
| 54 | |
| 55 | if ((ptr->flags & IORESOURCE_MEM) && |
| 56 | strcmp(ptr->name, "System RAM") == 0) { |
| 57 | S3C_PMDBG("Found system RAM at %08lx..%08lx\n", |
| 58 | ptr->start, ptr->end); |
| 59 | arg = (fn)(ptr, arg); |
| 60 | } |
| 61 | |
| 62 | ptr = ptr->sibling; |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | static void s3c_pm_run_sysram(run_fn_t fn, u32 *arg) |
| 67 | { |
| 68 | s3c_pm_run_res(&iomem_resource, fn, arg); |
| 69 | } |
| 70 | |
| 71 | static u32 *s3c_pm_countram(struct resource *res, u32 *val) |
| 72 | { |
| 73 | u32 size = (u32)(res->end - res->start)+1; |
| 74 | |
| 75 | size += CHECK_CHUNKSIZE-1; |
| 76 | size /= CHECK_CHUNKSIZE; |
| 77 | |
| 78 | S3C_PMDBG("Area %08lx..%08lx, %d blocks\n", res->start, res->end, size); |
| 79 | |
| 80 | *val += size * sizeof(u32); |
| 81 | return val; |
| 82 | } |
| 83 | |
| 84 | /* s3c_pm_prepare_check |
| 85 | * |
| 86 | * prepare the necessary information for creating the CRCs. This |
| 87 | * must be done before the final save, as it will require memory |
| 88 | * allocating, and thus touching bits of the kernel we do not |
| 89 | * know about. |
| 90 | */ |
| 91 | |
| 92 | void s3c_pm_check_prepare(void) |
| 93 | { |
| 94 | crc_size = 0; |
| 95 | |
| 96 | s3c_pm_run_sysram(s3c_pm_countram, &crc_size); |
| 97 | |
| 98 | S3C_PMDBG("s3c_pm_prepare_check: %u checks needed\n", crc_size); |
| 99 | |
| 100 | crcs = kmalloc(crc_size+4, GFP_KERNEL); |
| 101 | if (crcs == NULL) |
| 102 | printk(KERN_ERR "Cannot allocated CRC save area\n"); |
| 103 | } |
| 104 | |
| 105 | static u32 *s3c_pm_makecheck(struct resource *res, u32 *val) |
| 106 | { |
| 107 | unsigned long addr, left; |
| 108 | |
| 109 | for (addr = res->start; addr < res->end; |
| 110 | addr += CHECK_CHUNKSIZE) { |
| 111 | left = res->end - addr; |
| 112 | |
| 113 | if (left > CHECK_CHUNKSIZE) |
| 114 | left = CHECK_CHUNKSIZE; |
| 115 | |
| 116 | *val = crc32_le(~0, phys_to_virt(addr), left); |
| 117 | val++; |
| 118 | } |
| 119 | |
| 120 | return val; |
| 121 | } |
| 122 | |
| 123 | /* s3c_pm_check_store |
| 124 | * |
| 125 | * compute the CRC values for the memory blocks before the final |
| 126 | * sleep. |
| 127 | */ |
| 128 | |
| 129 | void s3c_pm_check_store(void) |
| 130 | { |
| 131 | if (crcs != NULL) |
| 132 | s3c_pm_run_sysram(s3c_pm_makecheck, crcs); |
| 133 | } |
| 134 | |
| 135 | /* in_region |
| 136 | * |
| 137 | * return TRUE if the area defined by ptr..ptr+size contains the |
| 138 | * what..what+whatsz |
| 139 | */ |
| 140 | |
| 141 | static inline int in_region(void *ptr, int size, void *what, size_t whatsz) |
| 142 | { |
| 143 | if ((what+whatsz) < ptr) |
| 144 | return 0; |
| 145 | |
| 146 | if (what > (ptr+size)) |
| 147 | return 0; |
| 148 | |
| 149 | return 1; |
| 150 | } |
| 151 | |
| 152 | /** |
| 153 | * s3c_pm_runcheck*() - helper to check a resource on restore. |
| 154 | * @res: The resource to check |
| 155 | * @vak: Pointer to list of CRC32 values to check. |
| 156 | * |
| 157 | * Called from the s3c_pm_check_restore() via s3c_pm_run_sysram(), this |
| 158 | * function runs the given memory resource checking it against the stored |
| 159 | * CRC to ensure that memory is restored. The function tries to skip as |
| 160 | * many of the areas used during the suspend process. |
| 161 | */ |
| 162 | static u32 *s3c_pm_runcheck(struct resource *res, u32 *val) |
| 163 | { |
| 164 | void *save_at = phys_to_virt(s3c_sleep_save_phys); |
| 165 | unsigned long addr; |
| 166 | unsigned long left; |
| 167 | void *ptr; |
| 168 | u32 calc; |
| 169 | |
| 170 | for (addr = res->start; addr < res->end; |
| 171 | addr += CHECK_CHUNKSIZE) { |
| 172 | left = res->end - addr; |
| 173 | |
| 174 | if (left > CHECK_CHUNKSIZE) |
| 175 | left = CHECK_CHUNKSIZE; |
| 176 | |
| 177 | ptr = phys_to_virt(addr); |
| 178 | |
| 179 | if (in_region(ptr, left, crcs, crc_size)) { |
| 180 | S3C_PMDBG("skipping %08lx, has crc block in\n", addr); |
| 181 | goto skip_check; |
| 182 | } |
| 183 | |
| 184 | if (in_region(ptr, left, save_at, 32*4 )) { |
| 185 | S3C_PMDBG("skipping %08lx, has save block in\n", addr); |
| 186 | goto skip_check; |
| 187 | } |
| 188 | |
| 189 | /* calculate and check the checksum */ |
| 190 | |
| 191 | calc = crc32_le(~0, ptr, left); |
| 192 | if (calc != *val) { |
| 193 | printk(KERN_ERR "Restore CRC error at " |
| 194 | "%08lx (%08x vs %08x)\n", addr, calc, *val); |
| 195 | |
| 196 | S3C_PMDBG("Restore CRC error at %08lx (%08x vs %08x)\n", |
| 197 | addr, calc, *val); |
| 198 | } |
| 199 | |
| 200 | skip_check: |
| 201 | val++; |
| 202 | } |
| 203 | |
| 204 | return val; |
| 205 | } |
| 206 | |
| 207 | /** |
| 208 | * s3c_pm_check_restore() - memory check called on resume |
| 209 | * |
| 210 | * check the CRCs after the restore event and free the memory used |
| 211 | * to hold them |
| 212 | */ |
| 213 | void s3c_pm_check_restore(void) |
| 214 | { |
| 215 | if (crcs != NULL) { |
| 216 | s3c_pm_run_sysram(s3c_pm_runcheck, crcs); |
| 217 | kfree(crcs); |
| 218 | crcs = NULL; |
| 219 | } |
| 220 | } |