3 files changed, 233 insertions, 0 deletions

diff --git a/arch/arm/plat-s3c/Makefile b/arch/arm/plat-s3c/Makefile
index afd8d089ba16..8d7815d25a51 100644
--- a/arch/arm/plat-s3c/Makefile
+++ b/arch/arm/plat-s3c/Makefile
@@ -21,6 +21,7 @@ obj-y				+= gpio-config.o
 # PM support
 
 obj-$(CONFIG_PM)                += pm.o
+obj-$(CONFIG_S3C2410_PM_CHECK)  += pm-check.o
 
 # devices
 
diff --git a/arch/arm/plat-s3c/include/plat/pm.h b/arch/arm/plat-s3c/include/plat/pm.h
index a1520997ab82..95c2612d4976 100644
--- a/arch/arm/plat-s3c/include/plat/pm.h
+++ b/arch/arm/plat-s3c/include/plat/pm.h
@@ -101,3 +101,15 @@ extern void s3c_pm_dbg(const char *msg, ...);
 #else
 #define S3C_PMDBG(fmt...) printk(KERN_DEBUG fmt)
 #endif
+
+/* suspend memory checking */
+
+#ifdef CONFIG_S3C2410_PM_CHECK
+extern void s3c_pm_check_prepare(void);
+extern void s3c_pm_check_restore(void);
+extern void s3c_pm_check_store(void);
+#else
+#define s3c_pm_check_prepare() do { } while(0)
+#define s3c_pm_check_restore() do { } while(0)
+#define s3c_pm_check_store()   do { } while(0)
+#endif
diff --git a/arch/arm/plat-s3c/pm-check.c b/arch/arm/plat-s3c/pm-check.c
new file mode 100644
index 000000000000..95ba7693b5af
--- /dev/null
+++ b/arch/arm/plat-s3c/pm-check.c
@@ -0,0 +1,220 @@
+/* linux/arch/arm/plat-s3c/pm-check.c
+ *  originally in linux/arch/arm/plat-s3c24xx/pm.c
+ *
+ * Copyright (c) 2004,2006,2008 Simtec Electronics
+ *      http://armlinux.simtec.co.uk
+ *      Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C Power Mangament - suspend/resume memory corruptiuon check.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/kernel.h>
+#include <linux/suspend.h>
+#include <linux/init.h>
+#include <linux/crc32.h>
+#include <linux/ioport.h>
+
+#include <plat/pm.h>
+
+#if CONFIG_S3C2410_PM_CHECK_CHUNKSIZE < 1
+#error CONFIG_S3C2410_PM_CHECK_CHUNKSIZE must be a positive non-zero value
+#endif
+
+/* suspend checking code...
+ *
+ * this next area does a set of crc checks over all the installed
+ * memory, so the system can verify if the resume was ok.
+ *
+ * CONFIG_S3C2410_PM_CHECK_CHUNKSIZE defines the block-size for the CRC,
+ * increasing it will mean that the area corrupted will be less easy to spot,
+ * and reducing the size will cause the CRC save area to grow
+*/
+
+#define CHECK_CHUNKSIZE (CONFIG_S3C2410_PM_CHECK_CHUNKSIZE * 1024)
+
+static u32 crc_size;    /* size needed for the crc block */
+static u32 *crcs;       /* allocated over suspend/resume */
+
+typedef u32 *(run_fn_t)(struct resource *ptr, u32 *arg);
+
+/* s3c_pm_run_res
+ *
+ * go through the given resource list, and look for system ram
+*/
+
+static void s3c_pm_run_res(struct resource *ptr, run_fn_t fn, u32 *arg)
+{
+        while (ptr != NULL) {
+                if (ptr->child != NULL)
+                        s3c_pm_run_res(ptr->child, fn, arg);
+
+                if ((ptr->flags & IORESOURCE_MEM) &&
+                    strcmp(ptr->name, "System RAM") == 0) {
+                        S3C_PMDBG("Found system RAM at %08lx..%08lx\n",
+                            ptr->start, ptr->end);
+                        arg = (fn)(ptr, arg);
+                }
+
+                ptr = ptr->sibling;
+        }
+}
+
+static void s3c_pm_run_sysram(run_fn_t fn, u32 *arg)
+{
+        s3c_pm_run_res(&iomem_resource, fn, arg);
+}
+
+static u32 *s3c_pm_countram(struct resource *res, u32 *val)
+{
+        u32 size = (u32)(res->end - res->start)+1;
+
+        size += CHECK_CHUNKSIZE-1;
+        size /= CHECK_CHUNKSIZE;
+
+        S3C_PMDBG("Area %08lx..%08lx, %d blocks\n", res->start, res->end, size);
+
+        *val += size * sizeof(u32);
+        return val;
+}
+
+/* s3c_pm_prepare_check
+ *
+ * prepare the necessary information for creating the CRCs. This
+ * must be done before the final save, as it will require memory
+ * allocating, and thus touching bits of the kernel we do not
+ * know about.
+*/
+
+void s3c_pm_check_prepare(void)
+{
+        crc_size = 0;
+
+        s3c_pm_run_sysram(s3c_pm_countram, &crc_size);
+
+        S3C_PMDBG("s3c_pm_prepare_check: %u checks needed\n", crc_size);
+
+        crcs = kmalloc(crc_size+4, GFP_KERNEL);
+        if (crcs == NULL)
+                printk(KERN_ERR "Cannot allocated CRC save area\n");
+}
+
+static u32 *s3c_pm_makecheck(struct resource *res, u32 *val)
+{
+        unsigned long addr, left;
+
+        for (addr = res->start; addr < res->end;
+             addr += CHECK_CHUNKSIZE) {
+                left = res->end - addr;
+
+                if (left > CHECK_CHUNKSIZE)
+                        left = CHECK_CHUNKSIZE;
+
+                *val = crc32_le(~0, phys_to_virt(addr), left);
+                val++;
+        }
+
+        return val;
+}
+
+/* s3c_pm_check_store
+ *
+ * compute the CRC values for the memory blocks before the final
+ * sleep.
+*/
+
+void s3c_pm_check_store(void)
+{
+        if (crcs != NULL)
+                s3c_pm_run_sysram(s3c_pm_makecheck, crcs);
+}
+
+/* in_region
+ *
+ * return TRUE if the area defined by ptr..ptr+size contains the
+ * what..what+whatsz
+*/
+
+static inline int in_region(void *ptr, int size, void *what, size_t whatsz)
+{
+        if ((what+whatsz) < ptr)
+                return 0;
+
+        if (what > (ptr+size))
+                return 0;
+
+        return 1;
+}
+
+/**
+ * s3c_pm_runcheck*() - helper to check a resource on restore.
+ * @res: The resource to check
+ * @vak: Pointer to list of CRC32 values to check.
+ *
+ * Called from the s3c_pm_check_restore() via s3c_pm_run_sysram(), this
+ * function runs the given memory resource checking it against the stored
+ * CRC to ensure that memory is restored. The function tries to skip as
+ * many of the areas used during the suspend process.
+ */
+static u32 *s3c_pm_runcheck(struct resource *res, u32 *val)
+{
+        void *save_at = phys_to_virt(s3c_sleep_save_phys);
+        unsigned long addr;
+        unsigned long left;
+        void *ptr;
+        u32 calc;
+
+        for (addr = res->start; addr < res->end;
+             addr += CHECK_CHUNKSIZE) {
+                left = res->end - addr;
+
+                if (left > CHECK_CHUNKSIZE)
+                        left = CHECK_CHUNKSIZE;
+
+                ptr = phys_to_virt(addr);
+
+                if (in_region(ptr, left, crcs, crc_size)) {
+                        S3C_PMDBG("skipping %08lx, has crc block in\n", addr);
+                        goto skip_check;
+                }
+
+                if (in_region(ptr, left, save_at, 32*4 )) {
+                        S3C_PMDBG("skipping %08lx, has save block in\n", addr);
+                        goto skip_check;
+                }
+
+                /* calculate and check the checksum */
+
+                calc = crc32_le(~0, ptr, left);
+                if (calc != *val) {
+                        printk(KERN_ERR "Restore CRC error at "
+                               "%08lx (%08x vs %08x)\n", addr, calc, *val);
+
+                        S3C_PMDBG("Restore CRC error at %08lx (%08x vs %08x)\n",
+                            addr, calc, *val);
+                }
+
+        skip_check:
+                val++;
+        }
+
+        return val;
+}
+
+/**
+ * s3c_pm_check_restore() - memory check called on resume
+ *
+ * check the CRCs after the restore event and free the memory used
+ * to hold them
+*/
+void s3c_pm_check_restore(void)
+{
+        if (crcs != NULL) {
+                s3c_pm_run_sysram(s3c_pm_runcheck, crcs);
+                kfree(crcs);
+                crcs = NULL;
+        }
+}