USB: serial: option: reimplement interface masking
[linux/fpc-iii.git] / arch / arm / plat-samsung / pm-check.c
blobcd2c02c68bc3aa1ace7a584b2591886bedc81c1d
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // originally in linux/arch/arm/plat-s3c24xx/pm.c
4 //
5 // Copyright (c) 2004-2008 Simtec Electronics
6 // http://armlinux.simtec.co.uk
7 // Ben Dooks <ben@simtec.co.uk>
8 //
9 // S3C Power Mangament - suspend/resume memory corruption check.
11 #include <linux/kernel.h>
12 #include <linux/suspend.h>
13 #include <linux/init.h>
14 #include <linux/crc32.h>
15 #include <linux/ioport.h>
16 #include <linux/slab.h>
18 #include <plat/pm-common.h>
20 #if CONFIG_SAMSUNG_PM_CHECK_CHUNKSIZE < 1
21 #error CONFIG_SAMSUNG_PM_CHECK_CHUNKSIZE must be a positive non-zero value
22 #endif
24 /* suspend checking code...
26 * this next area does a set of crc checks over all the installed
27 * memory, so the system can verify if the resume was ok.
29 * CONFIG_SAMSUNG_PM_CHECK_CHUNKSIZE defines the block-size for the CRC,
30 * increasing it will mean that the area corrupted will be less easy to spot,
31 * and reducing the size will cause the CRC save area to grow
34 #define CHECK_CHUNKSIZE (CONFIG_SAMSUNG_PM_CHECK_CHUNKSIZE * 1024)
36 static u32 crc_size; /* size needed for the crc block */
37 static u32 *crcs; /* allocated over suspend/resume */
39 typedef u32 *(run_fn_t)(struct resource *ptr, u32 *arg);
41 /* s3c_pm_run_res
43 * go through the given resource list, and look for system ram
46 static void s3c_pm_run_res(struct resource *ptr, run_fn_t fn, u32 *arg)
48 while (ptr != NULL) {
49 if (ptr->child != NULL)
50 s3c_pm_run_res(ptr->child, fn, arg);
52 if ((ptr->flags & IORESOURCE_SYSTEM_RAM)
53 == IORESOURCE_SYSTEM_RAM) {
54 S3C_PMDBG("Found system RAM at %08lx..%08lx\n",
55 (unsigned long)ptr->start,
56 (unsigned long)ptr->end);
57 arg = (fn)(ptr, arg);
60 ptr = ptr->sibling;
64 static void s3c_pm_run_sysram(run_fn_t fn, u32 *arg)
66 s3c_pm_run_res(&iomem_resource, fn, arg);
69 static u32 *s3c_pm_countram(struct resource *res, u32 *val)
71 u32 size = (u32)resource_size(res);
73 size += CHECK_CHUNKSIZE-1;
74 size /= CHECK_CHUNKSIZE;
76 S3C_PMDBG("Area %08lx..%08lx, %d blocks\n",
77 (unsigned long)res->start, (unsigned long)res->end, size);
79 *val += size * sizeof(u32);
80 return val;
83 /* s3c_pm_prepare_check
85 * prepare the necessary information for creating the CRCs. This
86 * must be done before the final save, as it will require memory
87 * allocating, and thus touching bits of the kernel we do not
88 * know about.
91 void s3c_pm_check_prepare(void)
93 crc_size = 0;
95 s3c_pm_run_sysram(s3c_pm_countram, &crc_size);
97 S3C_PMDBG("s3c_pm_prepare_check: %u checks needed\n", crc_size);
99 crcs = kmalloc(crc_size+4, GFP_KERNEL);
100 if (crcs == NULL)
101 printk(KERN_ERR "Cannot allocated CRC save area\n");
104 static u32 *s3c_pm_makecheck(struct resource *res, u32 *val)
106 unsigned long addr, left;
108 for (addr = res->start; addr < res->end;
109 addr += CHECK_CHUNKSIZE) {
110 left = res->end - addr;
112 if (left > CHECK_CHUNKSIZE)
113 left = CHECK_CHUNKSIZE;
115 *val = crc32_le(~0, phys_to_virt(addr), left);
116 val++;
119 return val;
122 /* s3c_pm_check_store
124 * compute the CRC values for the memory blocks before the final
125 * sleep.
128 void s3c_pm_check_store(void)
130 if (crcs != NULL)
131 s3c_pm_run_sysram(s3c_pm_makecheck, crcs);
134 /* in_region
136 * return TRUE if the area defined by ptr..ptr+size contains the
137 * what..what+whatsz
140 static inline int in_region(void *ptr, int size, void *what, size_t whatsz)
142 if ((what+whatsz) < ptr)
143 return 0;
145 if (what > (ptr+size))
146 return 0;
148 return 1;
152 * s3c_pm_runcheck() - helper to check a resource on restore.
153 * @res: The resource to check
154 * @vak: Pointer to list of CRC32 values to check.
156 * Called from the s3c_pm_check_restore() via s3c_pm_run_sysram(), this
157 * function runs the given memory resource checking it against the stored
158 * CRC to ensure that memory is restored. The function tries to skip as
159 * many of the areas used during the suspend process.
161 static u32 *s3c_pm_runcheck(struct resource *res, u32 *val)
163 unsigned long addr;
164 unsigned long left;
165 void *stkpage;
166 void *ptr;
167 u32 calc;
169 stkpage = (void *)((u32)&calc & ~PAGE_MASK);
171 for (addr = res->start; addr < res->end;
172 addr += CHECK_CHUNKSIZE) {
173 left = res->end - addr;
175 if (left > CHECK_CHUNKSIZE)
176 left = CHECK_CHUNKSIZE;
178 ptr = phys_to_virt(addr);
180 if (in_region(ptr, left, stkpage, 4096)) {
181 S3C_PMDBG("skipping %08lx, has stack in\n", addr);
182 goto skip_check;
185 if (in_region(ptr, left, crcs, crc_size)) {
186 S3C_PMDBG("skipping %08lx, has crc block in\n", addr);
187 goto skip_check;
190 /* calculate and check the checksum */
192 calc = crc32_le(~0, ptr, left);
193 if (calc != *val) {
194 printk(KERN_ERR "Restore CRC error at "
195 "%08lx (%08x vs %08x)\n", addr, calc, *val);
197 S3C_PMDBG("Restore CRC error at %08lx (%08x vs %08x)\n",
198 addr, calc, *val);
201 skip_check:
202 val++;
205 return val;
209 * s3c_pm_check_restore() - memory check called on resume
211 * check the CRCs after the restore event and free the memory used
212 * to hold them
214 void s3c_pm_check_restore(void)
216 if (crcs != NULL)
217 s3c_pm_run_sysram(s3c_pm_runcheck, crcs);
221 * s3c_pm_check_cleanup() - free memory resources
223 * Free the resources that where allocated by the suspend
224 * memory check code. We do this separately from the
225 * s3c_pm_check_restore() function as we cannot call any
226 * functions that might sleep during that resume.
228 void s3c_pm_check_cleanup(void)
230 kfree(crcs);
231 crcs = NULL;