ARM: samsung: move pm check code to drivers/soc

This is the only part of plat-samsung that is really
shared between the s3c and s5p ports. Moving it to
drivers/soc/ lets us make them completely independent.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200806182059.2431-16-krzk@kernel.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

4 files changed, 362 insertions, 1 deletions

diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
index 264185664594..5abe82079d2e 100644
--- a/drivers/soc/samsung/Kconfig
+++ b/drivers/soc/samsung/Kconfig
@@ -35,7 +35,53 @@ config EXYNOS_PMU_ARM_DRIVERS
 
 config EXYNOS_PM_DOMAINS
 	bool "Exynos PM domains" if COMPILE_TEST
-	depends on PM_GENERIC_DOMAINS || COMPILE_TEST
+	depends on (ARCH_EXYNOS && PM_GENERIC_DOMAINS) || COMPILE_TEST
+
+config SAMSUNG_PM_DEBUG
+	bool "Samsung PM Suspend debug"
+	depends on PM && DEBUG_KERNEL
+	depends on PLAT_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
+	depends on DEBUG_S3C24XX_UART || DEBUG_S3C2410_UART
+	help
+	  Say Y here if you want verbose debugging from the PM Suspend and
+	  Resume code. See <file:Documentation/arm/samsung-s3c24xx/suspend.rst>
+	  for more information.
+
+config S3C_PM_DEBUG_LED_SMDK
+       bool "SMDK LED suspend/resume debugging"
+       depends on PM && (MACH_SMDK6410)
+       help
+         Say Y here to enable the use of the SMDK LEDs on the baseboard
+	 for debugging of the state of the suspend and resume process.
+
+	 Note, this currently only works for S3C64XX based SMDK boards.
+
+config SAMSUNG_PM_CHECK
+	bool "S3C2410 PM Suspend Memory CRC"
+	depends on PM && (PLAT_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210)
+	select CRC32
+	help
+	  Enable the PM code's memory area checksum over sleep. This option
+	  will generate CRCs of all blocks of memory, and store them before
+	  going to sleep. The blocks are then checked on resume for any
+	  errors.
+
+	  Note, this can take several seconds depending on memory size
+	  and CPU speed.
+
+	  See <file:Documentation/arm/samsung-s3c24xx/suspend.rst>
+
+config SAMSUNG_PM_CHECK_CHUNKSIZE
+	int "S3C2410 PM Suspend CRC Chunksize (KiB)"
+	depends on PM && SAMSUNG_PM_CHECK
+	default 64
+	help
+	  Set the chunksize in Kilobytes of the CRC for checking memory
+	  corruption over suspend and resume. A smaller value will mean that
+	  the CRC data block will take more memory, but will identify any
+	  faults with better precision.
+
+	  See <file:Documentation/arm/samsung-s3c24xx/suspend.rst>
 
 config EXYNOS_REGULATOR_COUPLER
 	bool "Exynos SoC Regulator Coupler" if COMPILE_TEST
diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
index ecc3a32f6406..59e8e9453f27 100644
--- a/drivers/soc/samsung/Makefile
+++ b/drivers/soc/samsung/Makefile
@@ -10,3 +10,6 @@ obj-$(CONFIG_EXYNOS_PMU_ARM_DRIVERS)	+= exynos3250-pmu.o exynos4-pmu.o \
 					exynos5250-pmu.o exynos5420-pmu.o
 obj-$(CONFIG_EXYNOS_PM_DOMAINS) += pm_domains.o
 obj-$(CONFIG_EXYNOS_REGULATOR_COUPLER) += exynos-regulator-coupler.o
+
+obj-$(CONFIG_SAMSUNG_PM_CHECK)	+= s3c-pm-check.o
+obj-$(CONFIG_SAMSUNG_PM_DEBUG)	+= s3c-pm-debug.o
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;
+}
+
diff --git a/drivers/soc/samsung/s3c-pm-debug.c b/drivers/soc/samsung/s3c-pm-debug.c
new file mode 100644
index 000000000000..b5ce0e9a41e5
--- /dev/null
+++ b/drivers/soc/samsung/s3c-pm-debug.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (C) 2013 Samsung Electronics Co., Ltd.
+//	Tomasz Figa <t.figa@samsung.com>
+// Copyright (C) 2008 Openmoko, Inc.
+// Copyright (C) 2004-2008 Simtec Electronics
+//	Ben Dooks <ben@simtec.co.uk>
+//	http://armlinux.simtec.co.uk/
+//
+// Samsung common power management (suspend to RAM) debug support
+
+#include <linux/serial_core.h>
+#include <linux/serial_s3c.h>
+#include <linux/io.h>
+
+#include <asm/mach/map.h>
+
+#include <linux/soc/samsung/s3c-pm.h>
+
+static struct pm_uart_save uart_save;
+
+extern void printascii(const char *);
+
+void s3c_pm_dbg(const char *fmt, ...)
+{
+	va_list va;
+	char buff[256];
+
+	va_start(va, fmt);
+	vsnprintf(buff, sizeof(buff), fmt, va);
+	va_end(va);
+
+	printascii(buff);
+}
+
+static inline void __iomem *s3c_pm_uart_base(void)
+{
+	unsigned long paddr;
+	unsigned long vaddr;
+
+	debug_ll_addr(&paddr, &vaddr);
+
+	return (void __iomem *)vaddr;
+}
+
+void s3c_pm_save_uarts(bool is_s3c2410)
+{
+	void __iomem *regs = s3c_pm_uart_base();
+	struct pm_uart_save *save = &uart_save;
+
+	save->ulcon = __raw_readl(regs + S3C2410_ULCON);
+	save->ucon = __raw_readl(regs + S3C2410_UCON);
+	save->ufcon = __raw_readl(regs + S3C2410_UFCON);
+	save->umcon = __raw_readl(regs + S3C2410_UMCON);
+	save->ubrdiv = __raw_readl(regs + S3C2410_UBRDIV);
+
+	if (!is_s3c2410)
+		save->udivslot = __raw_readl(regs + S3C2443_DIVSLOT);
+
+	S3C_PMDBG("UART[%p]: ULCON=%04x, UCON=%04x, UFCON=%04x, UBRDIV=%04x\n",
+		  regs, save->ulcon, save->ucon, save->ufcon, save->ubrdiv);
+}
+
+void s3c_pm_restore_uarts(bool is_s3c2410)
+{
+	void __iomem *regs = s3c_pm_uart_base();
+	struct pm_uart_save *save = &uart_save;
+
+	s3c_pm_arch_update_uart(regs, save);
+
+	__raw_writel(save->ulcon, regs + S3C2410_ULCON);
+	__raw_writel(save->ucon,  regs + S3C2410_UCON);
+	__raw_writel(save->ufcon, regs + S3C2410_UFCON);
+	__raw_writel(save->umcon, regs + S3C2410_UMCON);
+	__raw_writel(save->ubrdiv, regs + S3C2410_UBRDIV);
+
+	if (!is_s3c2410)
+		__raw_writel(save->udivslot, regs + S3C2443_DIVSLOT);
+}