Merge tag 'linux-watchdog-6.17-rc1' of git://www.linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:

 - sbsa: Adjust keepalive timeout to avoid MediaTek WS0 race condition

 - Various improvements and fixes

* tag 'linux-watchdog-6.17-rc1' of git://www.linux-watchdog.org/linux-watchdog:
  watchdog: sbsa: Adjust keepalive timeout to avoid MediaTek WS0 race condition
  watchdog: dw_wdt: Fix default timeout
  watchdog: Don't use "proxy" headers
  watchdog: it87_wdt: Don't use "proxy" headers
  watchdog: renesas_wdt: Convert to DEFINE_SIMPLE_DEV_PM_OPS()
  watchdog: iTCO_wdt: Report error if timeout configuration fails
  watchdog: rti_wdt: Use of_reserved_mem_region_to_resource() for "memory-region"
  dt-bindings: watchdog: nxp,pnx4008-wdt: allow clocks property
  watchdog: ziirave_wdt: check record length in ziirave_firm_verify()

Documentation/devicetree/bindings/watchdog/nxp,pnx4008-wdt.yaml

@@ -19,6 +19,9 @@ properties:
   reg:
     maxItems: 1
 
+  clocks:
+    maxItems: 1
+
 required:
   - compatible
   - reg

drivers/watchdog/dw_wdt.c

@@ -644,6 +644,8 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
 	} else {
 		wdd->timeout = DW_WDT_DEFAULT_SECONDS;
 		watchdog_init_timeout(wdd, 0, dev);
+		/* Limit timeout value to hardware constraints. */
+		dw_wdt_set_timeout(wdd, wdd->timeout);
 	}
 
 	platform_set_drvdata(pdev, dw_wdt);

drivers/watchdog/iTCO_wdt.c

@@ -577,7 +577,11 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
 	/* Check that the heartbeat value is within it's range;
 	   if not reset to the default */
 	if (iTCO_wdt_set_timeout(&p->wddev, heartbeat)) {
-		iTCO_wdt_set_timeout(&p->wddev, WATCHDOG_TIMEOUT);
+		ret = iTCO_wdt_set_timeout(&p->wddev, WATCHDOG_TIMEOUT);
+		if (ret != 0) {
+			dev_err(dev, "Failed to set watchdog timeout (%d)\n", WATCHDOG_TIMEOUT);
+			return ret;
+		}
 		dev_info(dev, "timeout value out of range, using %d\n",
 			WATCHDOG_TIMEOUT);
 		heartbeat = WATCHDOG_TIMEOUT;

drivers/watchdog/it87_wdt.c

@@ -22,11 +22,13 @@
 
 #include <linux/bits.h>
 #include <linux/dmi.h>
+#include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/io.h>
-#include <linux/kernel.h>
+#include <linux/ioport.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/printk.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
 

drivers/watchdog/renesas_wdt.c

@@ -300,7 +300,7 @@ static void rwdt_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 }
 
-static int __maybe_unused rwdt_suspend(struct device *dev)
+static int rwdt_suspend(struct device *dev)
 {
 	struct rwdt_priv *priv = dev_get_drvdata(dev);
 
@@ -310,7 +310,7 @@ static int __maybe_unused rwdt_suspend(struct device *dev)
 	return 0;
 }
 
-static int __maybe_unused rwdt_resume(struct device *dev)
+static int rwdt_resume(struct device *dev)
 {
 	struct rwdt_priv *priv = dev_get_drvdata(dev);
 
@@ -320,7 +320,7 @@ static int __maybe_unused rwdt_resume(struct device *dev)
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(rwdt_pm_ops, rwdt_suspend, rwdt_resume);
+static DEFINE_SIMPLE_DEV_PM_OPS(rwdt_pm_ops, rwdt_suspend, rwdt_resume);
 
 static const struct of_device_id rwdt_ids[] = {
 	{ .compatible = "renesas,rcar-gen2-wdt", },
@@ -334,7 +334,7 @@ static struct platform_driver rwdt_driver = {
 	.driver = {
 		.name = "renesas_wdt",
 		.of_match_table = rwdt_ids,
-		.pm = &rwdt_pm_ops,
+		.pm = pm_sleep_ptr(&rwdt_pm_ops),
 	},
 	.probe = rwdt_probe,
 	.remove = rwdt_remove,

drivers/watchdog/rti_wdt.c

@@ -15,7 +15,7 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/of.h>
-#include <linux/of_address.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/types.h>
@@ -214,7 +214,6 @@ static int rti_wdt_probe(struct platform_device *pdev)
 	struct rti_wdt_device *wdt;
 	struct clk *clk;
 	u32 last_ping = 0;
-	struct device_node *node;
 	u32 reserved_mem_size;
 	struct resource res;
 	u32 *vaddr;
@@ -299,15 +298,8 @@ static int rti_wdt_probe(struct platform_device *pdev)
 		}
 	}
 
-	node = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
-	if (node) {
-		ret = of_address_to_resource(node, 0, &res);
-		of_node_put(node);
-		if (ret) {
-			dev_err(dev, "No memory address assigned to the region.\n");
-			goto err_iomap;
-		}
-
+	ret = of_reserved_mem_region_to_resource(pdev->dev.of_node, 0, &res);
+	if (!ret) {
 		/*
 		 * If reserved memory is defined for watchdog reset cause.
 		 * Readout the Power-on(PON) reason and pass to bootstatus.

drivers/watchdog/sbsa_gwdt.c

@@ -75,11 +75,17 @@
 #define SBSA_GWDT_VERSION_MASK  0xF
 #define SBSA_GWDT_VERSION_SHIFT 16
 
+#define SBSA_GWDT_IMPL_MASK	0x7FF
+#define SBSA_GWDT_IMPL_SHIFT	0
+#define SBSA_GWDT_IMPL_MEDIATEK	0x426
+
 /**
  * struct sbsa_gwdt - Internal representation of the SBSA GWDT
  * @wdd:		kernel watchdog_device structure
  * @clk:		store the System Counter clock frequency, in Hz.
  * @version:            store the architecture version
+ * @need_ws0_race_workaround:
+ *			indicate whether to adjust wdd->timeout to avoid a race with WS0
  * @refresh_base:	Virtual address of the watchdog refresh frame
  * @control_base:	Virtual address of the watchdog control frame
  */
@@ -87,6 +93,7 @@ struct sbsa_gwdt {
 	struct watchdog_device	wdd;
 	u32			clk;
 	int			version;
+	bool			need_ws0_race_workaround;
 	void __iomem		*refresh_base;
 	void __iomem		*control_base;
 };
@@ -161,6 +168,31 @@ static int sbsa_gwdt_set_timeout(struct watchdog_device *wdd,
 		 */
 		sbsa_gwdt_reg_write(((u64)gwdt->clk / 2) * timeout, gwdt);
 
+	/*
+	 * Some watchdog hardware has a race condition where it will ignore
+	 * sbsa_gwdt_keepalive() if it is called at the exact moment that a
+	 * timeout occurs and WS0 is being asserted. Unfortunately, the default
+	 * behavior of the watchdog core is very likely to trigger this race
+	 * when action=0 because it programs WOR to be half of the desired
+	 * timeout, and watchdog_next_keepalive() chooses the exact same time to
+	 * send keepalive pings.
+	 *
+	 * This triggers a race where sbsa_gwdt_keepalive() can be called right
+	 * as WS0 is being asserted, and affected hardware will ignore that
+	 * write and continue to assert WS0. After another (timeout / 2)
+	 * seconds, the same race happens again. If the driver wins then the
+	 * explicit refresh will reset WS0 to false but if the hardware wins,
+	 * then WS1 is asserted and the system resets.
+	 *
+	 * Avoid the problem by scheduling keepalive heartbeats one second later
+	 * than the WOR timeout.
+	 *
+	 * This workaround might not be needed in a future revision of the
+	 * hardware.
+	 */
+	if (gwdt->need_ws0_race_workaround)
+		wdd->min_hw_heartbeat_ms = timeout * 500 + 1000;
+
 	return 0;
 }
 
@@ -202,12 +234,15 @@ static int sbsa_gwdt_keepalive(struct watchdog_device *wdd)
 static void sbsa_gwdt_get_version(struct watchdog_device *wdd)
 {
 	struct sbsa_gwdt *gwdt = watchdog_get_drvdata(wdd);
-	int ver;
+	int iidr, ver, impl;
 
-	ver = readl(gwdt->control_base + SBSA_GWDT_W_IIDR);
-	ver = (ver >> SBSA_GWDT_VERSION_SHIFT) & SBSA_GWDT_VERSION_MASK;
+	iidr = readl(gwdt->control_base + SBSA_GWDT_W_IIDR);
+	ver = (iidr >> SBSA_GWDT_VERSION_SHIFT) & SBSA_GWDT_VERSION_MASK;
+	impl = (iidr >> SBSA_GWDT_IMPL_SHIFT) & SBSA_GWDT_IMPL_MASK;
 
 	gwdt->version = ver;
+	gwdt->need_ws0_race_workaround =
+		!action && (impl == SBSA_GWDT_IMPL_MEDIATEK);
 }
 
 static int sbsa_gwdt_start(struct watchdog_device *wdd)
@@ -299,6 +334,15 @@ static int sbsa_gwdt_probe(struct platform_device *pdev)
 	else
 		wdd->max_hw_heartbeat_ms = GENMASK_ULL(47, 0) / gwdt->clk * 1000;
 
+	if (gwdt->need_ws0_race_workaround) {
+		/*
+		 * A timeout of 3 seconds means that WOR will be set to 1.5
+		 * seconds and the heartbeat will be scheduled every 2.5
+		 * seconds.
+		 */
+		wdd->min_timeout = 3;
+	}
+
 	status = readl(cf_base + SBSA_GWDT_WCS);
 	if (status & SBSA_GWDT_WCS_WS1) {
 		dev_warn(dev, "System reset by WDT.\n");

drivers/watchdog/watchdog_core.h

@@ -24,8 +24,14 @@
  *	This material is provided "AS-IS" and at no charge.
  */
 
-#include <linux/hrtimer.h>
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/hrtimer_types.h>
+#include <linux/init.h>
 #include <linux/kthread.h>
+#include <linux/mutex_types.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
 
 #define MAX_DOGS	32	/* Maximum number of watchdog devices */
 

drivers/watchdog/watchdog_pretimeout.c

@@ -7,6 +7,8 @@
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
 #include <linux/watchdog.h>
 
 #include "watchdog_core.h"

drivers/watchdog/ziirave_wdt.c

@@ -302,6 +302,9 @@ static int ziirave_firm_verify(struct watchdog_device *wdd,
 		const u16 len = be16_to_cpu(rec->len);
 		const u32 addr = be32_to_cpu(rec->addr);
 
+		if (len > sizeof(data))
+			return -EINVAL;
+
 		if (ziirave_firm_addr_readonly(addr))
 			continue;
 

include/linux/watchdog.h

@@ -9,14 +9,18 @@
 #ifndef _LINUX_WATCHDOG_H
 #define _LINUX_WATCHDOG_H
 
-
 #include <linux/bitops.h>
-#include <linux/cdev.h>
-#include <linux/device.h>
-#include <linux/kernel.h>
+#include <linux/limits.h>
 #include <linux/notifier.h>
+#include <linux/printk.h>
+#include <linux/types.h>
+
 #include <uapi/linux/watchdog.h>
 
+struct attribute_group;
+struct device;
+struct module;
+
 struct watchdog_ops;
 struct watchdog_device;
 struct watchdog_core_data;