From: Francois-Nicolas Muller <francois-nicolas.muller@intel.com>
To: wim@iguana.be
Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org,
Francois-Nicolas Muller <francois-nicolas.muller@intel.com>
Subject: [PATCH] TCO watchdog pretimeout handler
Date: Mon, 15 Jun 2015 17:00:29 +0200 [thread overview]
Message-ID: <1434380429-1069-1-git-send-email-francois-nicolas.muller@intel.com> (raw)
Use TCO watchdog first timeout (pretimeout) to dump CPU backtraces and ease
debug of watchdog expiration causes.
TCO logic generates a SCI interrupt, then its handler dumps all CPU backtraces
and calls panic (in order to execute registered panic callbacks).
SCI interrupt number (GPE) is configured from ACPI tables.
Change-Id: If7badb962008ff38560a02575d0d41f6aaa5f7fd
Signed-off-by: Francois-Nicolas Muller <francois-nicolas.muller@intel.com>
---
drivers/watchdog/iTCO_wdt.c | 51 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 51 insertions(+)
diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
index cf8c50d..3dd4175 100644
--- a/drivers/watchdog/iTCO_wdt.c
+++ b/drivers/watchdog/iTCO_wdt.c
@@ -67,6 +67,8 @@
#include <linux/io.h> /* For inb/outb/... */
#include <linux/mfd/core.h>
#include <linux/mfd/lpc_ich.h>
+#include <linux/nmi.h>
+#include <linux/acpi.h>
#include "iTCO_vendor.h"
@@ -124,6 +126,13 @@ module_param(turn_SMI_watchdog_clear_off, int, 0);
MODULE_PARM_DESC(turn_SMI_watchdog_clear_off,
"Turn off SMI clearing watchdog (depends on TCO-version)(default=1)");
+#define DEFAULT_PRETIMEOUT 0
+static bool pretimeout = DEFAULT_PRETIMEOUT;
+module_param(pretimeout, bool, 0);
+MODULE_PARM_DESC(pretimeout,
+ "Enable watchdog pretimeout (default="
+ __MODULE_STRING(DEFAULT_PRETIMEOUT) ")");
+
static int iTCO_wdt_active = 0;
/*
@@ -200,6 +209,45 @@ static int iTCO_wdt_unset_NO_REBOOT_bit(void)
return ret; /* returns: 0 = OK, -EIO = Error */
}
+static unsigned char *tco_hid = "8086229C";
+
+static u32 iTCO_wdt_pretimeout_handler(acpi_handle gpe_device, u32 gpe,
+ void *context)
+{
+ /* dump backtraces for all available cores */
+ trigger_all_cpu_backtrace();
+
+ /* call panic notifiers */
+ panic("Kernel Watchdog");
+
+ return ACPI_INTERRUPT_HANDLED;
+}
+
+static acpi_status __init iTCO_wdt_register_gpe(acpi_handle handle,
+ u32 lvl, void *context, void **rv)
+{
+ unsigned long long gpe;
+ acpi_status status;
+ union acpi_object object = { 0 };
+ struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
+
+ status = acpi_evaluate_object(handle, "_GPE", NULL, &buffer);
+ if (ACPI_FAILURE(status))
+ return status;
+
+ if (object.type != ACPI_TYPE_INTEGER)
+ return AE_BAD_DATA;
+
+ gpe = object.integer.value;
+ status = acpi_install_gpe_handler(NULL, gpe, ACPI_GPE_EDGE_TRIGGERED,
+ iTCO_wdt_pretimeout_handler, NULL);
+ if (ACPI_FAILURE(status))
+ return status;
+
+ acpi_enable_gpe(NULL, gpe);
+ return AE_OK;
+}
+
static int iTCO_wdt_start(struct watchdog_device *wd_dev)
{
unsigned int val;
@@ -625,6 +673,9 @@ static int __init iTCO_wdt_init_module(void)
if (err)
return err;
+ if (pretimeout)
+ acpi_get_devices(tco_hid, iTCO_wdt_register_gpe, NULL, NULL);
+
return 0;
}
--
1.9.1
next reply other threads:[~2015-06-15 15:01 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-15 15:00 Francois-Nicolas Muller [this message]
2015-06-15 18:29 ` [PATCH] TCO watchdog pretimeout handler Guenter Roeck
2015-06-16 13:45 ` [PATCH v2] " Francois-Nicolas Muller
2015-06-17 5:14 ` Guenter Roeck
2015-06-17 13:34 ` [PATCH v3] " Francois-Nicolas Muller
2015-06-17 16:06 ` Andy Shevchenko
2015-06-18 12:41 ` Muller, Francois-nicolas
2015-06-18 12:41 ` Muller, Francois-nicolas
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