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Diffstat (limited to 'drivers/soc/samsung/s3c-pm-check.c')
-rw-r--r--drivers/soc/samsung/s3c-pm-check.c233
1 files changed, 233 insertions, 0 deletions
diff --git a/drivers/soc/samsung/s3c-pm-check.c b/drivers/soc/samsung/s3c-pm-check.c
new file mode 100644
index 000000000000..ff3e099fc208
--- /dev/null
+++ b/drivers/soc/samsung/s3c-pm-check.c
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// originally in linux/arch/arm/plat-s3c24xx/pm.c
+//
+// Copyright (c) 2004-2008 Simtec Electronics
+// http://armlinux.simtec.co.uk
+// Ben Dooks <ben@simtec.co.uk>
+//
+// S3C Power Mangament - suspend/resume memory corruption check.
+
+#include <linux/kernel.h>
+#include <linux/suspend.h>
+#include <linux/init.h>
+#include <linux/crc32.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+
+#include <linux/soc/samsung/s3c-pm.h>
+
+#if CONFIG_SAMSUNG_PM_CHECK_CHUNKSIZE < 1
+#error CONFIG_SAMSUNG_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_SAMSUNG_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_SAMSUNG_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_SYSTEM_RAM)
+ == IORESOURCE_SYSTEM_RAM) {
+ S3C_PMDBG("Found system RAM at %08lx..%08lx\n",
+ (unsigned long)ptr->start,
+ (unsigned long)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)resource_size(res);
+
+ size += CHECK_CHUNKSIZE-1;
+ size /= CHECK_CHUNKSIZE;
+
+ S3C_PMDBG("Area %08lx..%08lx, %d blocks\n",
+ (unsigned long)res->start, (unsigned long)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)
+{
+ unsigned long addr;
+ unsigned long left;
+ void *stkpage;
+ void *ptr;
+ u32 calc;
+
+ stkpage = (void *)((u32)&calc & ~PAGE_MASK);
+
+ 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, stkpage, 4096)) {
+ S3C_PMDBG("skipping %08lx, has stack in\n", addr);
+ goto skip_check;
+ }
+
+ if (in_region(ptr, left, crcs, crc_size)) {
+ S3C_PMDBG("skipping %08lx, has crc 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);
+}
+
+/**
+ * s3c_pm_check_cleanup() - free memory resources
+ *
+ * Free the resources that where allocated by the suspend
+ * memory check code. We do this separately from the
+ * s3c_pm_check_restore() function as we cannot call any
+ * functions that might sleep during that resume.
+ */
+void s3c_pm_check_cleanup(void)
+{
+ kfree(crcs);
+ crcs = NULL;
+}
+