Linux 2.6.31.6
[linux/fpc-iii.git] / arch / arm / plat-s3c / pm-check.c
blob39f2555564da1d0e8e504964ec796c51ee87bc00
1 /* linux/arch/arm/plat-s3c/pm-check.c
2 * originally in linux/arch/arm/plat-s3c24xx/pm.c
4 * Copyright (c) 2004,2006,2008 Simtec Electronics
5 * http://armlinux.simtec.co.uk
6 * Ben Dooks <ben@simtec.co.uk>
8 * S3C Power Mangament - suspend/resume memory corruptiuon check.
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.
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>
21 #include <plat/pm.h>
23 #if CONFIG_S3C2410_PM_CHECK_CHUNKSIZE < 1
24 #error CONFIG_S3C2410_PM_CHECK_CHUNKSIZE must be a positive non-zero value
25 #endif
27 /* suspend checking code...
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.
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
37 #define CHECK_CHUNKSIZE (CONFIG_S3C2410_PM_CHECK_CHUNKSIZE * 1024)
39 static u32 crc_size; /* size needed for the crc block */
40 static u32 *crcs; /* allocated over suspend/resume */
42 typedef u32 *(run_fn_t)(struct resource *ptr, u32 *arg);
44 /* s3c_pm_run_res
46 * go through the given resource list, and look for system ram
49 static void s3c_pm_run_res(struct resource *ptr, run_fn_t fn, u32 *arg)
51 while (ptr != NULL) {
52 if (ptr->child != NULL)
53 s3c_pm_run_res(ptr->child, fn, arg);
55 if ((ptr->flags & IORESOURCE_MEM) &&
56 strcmp(ptr->name, "System RAM") == 0) {
57 S3C_PMDBG("Found system RAM at %08lx..%08lx\n",
58 (unsigned long)ptr->start,
59 (unsigned long)ptr->end);
60 arg = (fn)(ptr, arg);
63 ptr = ptr->sibling;
67 static void s3c_pm_run_sysram(run_fn_t fn, u32 *arg)
69 s3c_pm_run_res(&iomem_resource, fn, arg);
72 static u32 *s3c_pm_countram(struct resource *res, u32 *val)
74 u32 size = (u32)(res->end - res->start)+1;
76 size += CHECK_CHUNKSIZE-1;
77 size /= CHECK_CHUNKSIZE;
79 S3C_PMDBG("Area %08lx..%08lx, %d blocks\n",
80 (unsigned long)res->start, (unsigned long)res->end, size);
82 *val += size * sizeof(u32);
83 return val;
86 /* s3c_pm_prepare_check
88 * prepare the necessary information for creating the CRCs. This
89 * must be done before the final save, as it will require memory
90 * allocating, and thus touching bits of the kernel we do not
91 * know about.
94 void s3c_pm_check_prepare(void)
96 crc_size = 0;
98 s3c_pm_run_sysram(s3c_pm_countram, &crc_size);
100 S3C_PMDBG("s3c_pm_prepare_check: %u checks needed\n", crc_size);
102 crcs = kmalloc(crc_size+4, GFP_KERNEL);
103 if (crcs == NULL)
104 printk(KERN_ERR "Cannot allocated CRC save area\n");
107 static u32 *s3c_pm_makecheck(struct resource *res, u32 *val)
109 unsigned long addr, left;
111 for (addr = res->start; addr < res->end;
112 addr += CHECK_CHUNKSIZE) {
113 left = res->end - addr;
115 if (left > CHECK_CHUNKSIZE)
116 left = CHECK_CHUNKSIZE;
118 *val = crc32_le(~0, phys_to_virt(addr), left);
119 val++;
122 return val;
125 /* s3c_pm_check_store
127 * compute the CRC values for the memory blocks before the final
128 * sleep.
131 void s3c_pm_check_store(void)
133 if (crcs != NULL)
134 s3c_pm_run_sysram(s3c_pm_makecheck, crcs);
137 /* in_region
139 * return TRUE if the area defined by ptr..ptr+size contains the
140 * what..what+whatsz
143 static inline int in_region(void *ptr, int size, void *what, size_t whatsz)
145 if ((what+whatsz) < ptr)
146 return 0;
148 if (what > (ptr+size))
149 return 0;
151 return 1;
155 * s3c_pm_runcheck() - helper to check a resource on restore.
156 * @res: The resource to check
157 * @vak: Pointer to list of CRC32 values to check.
159 * Called from the s3c_pm_check_restore() via s3c_pm_run_sysram(), this
160 * function runs the given memory resource checking it against the stored
161 * CRC to ensure that memory is restored. The function tries to skip as
162 * many of the areas used during the suspend process.
164 static u32 *s3c_pm_runcheck(struct resource *res, u32 *val)
166 void *save_at = phys_to_virt(s3c_sleep_save_phys);
167 unsigned long addr;
168 unsigned long left;
169 void *stkpage;
170 void *ptr;
171 u32 calc;
173 stkpage = (void *)((u32)&calc & ~PAGE_MASK);
175 for (addr = res->start; addr < res->end;
176 addr += CHECK_CHUNKSIZE) {
177 left = res->end - addr;
179 if (left > CHECK_CHUNKSIZE)
180 left = CHECK_CHUNKSIZE;
182 ptr = phys_to_virt(addr);
184 if (in_region(ptr, left, stkpage, 4096)) {
185 S3C_PMDBG("skipping %08lx, has stack in\n", addr);
186 goto skip_check;
189 if (in_region(ptr, left, crcs, crc_size)) {
190 S3C_PMDBG("skipping %08lx, has crc block in\n", addr);
191 goto skip_check;
194 if (in_region(ptr, left, save_at, 32*4 )) {
195 S3C_PMDBG("skipping %08lx, has save block in\n", addr);
196 goto skip_check;
199 /* calculate and check the checksum */
201 calc = crc32_le(~0, ptr, left);
202 if (calc != *val) {
203 printk(KERN_ERR "Restore CRC error at "
204 "%08lx (%08x vs %08x)\n", addr, calc, *val);
206 S3C_PMDBG("Restore CRC error at %08lx (%08x vs %08x)\n",
207 addr, calc, *val);
210 skip_check:
211 val++;
214 return val;
218 * s3c_pm_check_restore() - memory check called on resume
220 * check the CRCs after the restore event and free the memory used
221 * to hold them
223 void s3c_pm_check_restore(void)
225 if (crcs != NULL)
226 s3c_pm_run_sysram(s3c_pm_runcheck, crcs);
230 * s3c_pm_check_cleanup() - free memory resources
232 * Free the resources that where allocated by the suspend
233 * memory check code. We do this separately from the
234 * s3c_pm_check_restore() function as we cannot call any
235 * functions that might sleep during that resume.
237 void s3c_pm_check_cleanup(void)
239 kfree(crcs);
240 crcs = NULL;