On Fri, Dec 05, 2014 at 10:08:45AM +0000, Muller, Francois-nicolas wrote:
This driver provides support for TCO watchdog warning interrupt.
Hi Francois,
Cc: Rafael and linux-acpi per his request on ACPI drivers (even if they are for
platform/drivers/x86).
This feature is useful to root cause watchdog expiration.
Would this not be better suited as a debug option to the iTCO_wdt.c driver under
drivers/watchdog?
Cc: Wim Van Sebroeck and linux-watchdog
Upon first expiration of the TCO watchdog, a warning interrupt is fired
to this driver, which calls panic() function and dumps debug information
(registers and call stacks).
Nit: Newlines between paragraphs for legibility here and in comments please.
This implies TCO watchdog driver has enabled the interrupt (SCI) and ACPI
tables contain GPE mapping information.
After the interrupt has been fired, TCO watchdog reloads automatically and
upon second expiration it trigs a reset of the platform.
triggers
Change-Id: I39b615b59dd4336bf208454f08b3e9eac9eb2880
Please run through checkpatch.pl (Gerrit change-id's should be removed).
Signed-off-by: Francois-Nicolas Muller <francois-nicolas.muller@xxxxxxxxx>
---
drivers/platform/x86/Kconfig | 13 +++++
drivers/platform/x86/Makefile | 1 +
drivers/platform/x86/intel_warn_int.c | 98 +++++++++++++++++++++++++++++++++
3 files changed, 112 insertions(+)
create mode 100644 drivers/platform/x86/intel_warn_int.c
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 5ae65c1..79cba16 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -827,4 +827,17 @@ config INTEL_BAYTRAIL_MBI
Interface. This is a requirement for systems that need to configure
the PUNIT for power management features such as RAPL.
+config INTEL_WARN_INT
+ tristate "TCO Watchdog warning interrupt"
+ depends on ITCO_WDT
+ ---help---
+ This driver provides support for TCO watchdog warning interrupt.
+ Upon first expiration of the TCO watchdog, a warning interrupt is
+ fired and the driver calls panic() function to dump debug information
s/function//
+ (registers and call stacks).
newline
+ At the same time, the TCO watchdog reloads with 2.4 seconds timeout
+ value and runs till the second expiration. At the second expiration of
s/till/until/
+ the TCO watchdog, the platform resets (the dump is supposed to last less
+ than 2.4 seconds).
+
endif # X86_PLATFORM_DEVICES
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 32caae3..2d47b4d 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -58,3 +58,4 @@ obj-$(CONFIG_PVPANIC) += pvpanic.o
obj-$(CONFIG_INTEL_BAYTRAIL_MBI) += intel_baytrail.o
obj-$(CONFIG_INTEL_SOC_PMIC) += dc_ti_cc.o
obj-$(CONFIG_ACPI) += intel_em_config.o
+obj-$(CONFIG_INTEL_WARN_INT) += intel_warn_int.o
diff --git a/drivers/platform/x86/intel_warn_int.c b/drivers/platform/x86/intel_warn_int.c
new file mode 100644
index 0000000..7ec8b73
--- /dev/null
+++ b/drivers/platform/x86/intel_warn_int.c
@@ -0,0 +1,98 @@
+/*
+ * intel_warn_int.c - This driver provides support for TCO watchdog warning
+ * interrupt.
Newlines between paragraphs in this section too.
+ * This feature is useful to root cause watchdog expiration.
+ * Upon first expiration of the TCO watchdog, a warning interrupt is fired
+ * to this driver, which calls panic() function and dumps debug information
s/function//
+ * (registers and call stacks).
+ * This implies TCO watchdog driver has enabled the interrupt (SCI) and ACPI
the ACPI...
+ * tables contain GPE mapping information.
the GPE...
+ * After the interrupt has been fired, TCO watchdog reloads automatically and
+ * upon second expiration it trigs a reset of the platform.
triggers
+ * Copyright (c) 2014, Intel Corporation.
All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
extra * line, can remove.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/acpi.h>
+#include <linux/nmi.h>
+#include <acpi/actypes.h>
+
+#define DRV_NAME "warn_int"
+#define TCO_CLASS DRV_NAME
+
+static const struct acpi_device_id tco_device_ids[] = {
+ {"8086229C", 0},
What is this device ID? Is it specific to a debug ID for the WDT? If not, will
this eventually conflict with a non-debug driver for this WDT?
+ {"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, tco_device_ids);
+
+static u32 warn_irq_handler(acpi_handle gpe_device, u32 gpe, void *context)
+{
+ pr_warn("[SHTDWN] %s, WATCHDOG TIMEOUT HANDLER!\n", __func__);
Indenting with 13 spaces? Please review Documentation/CodingStyle and update the
patch. Rather than point out all these sorts of errors, I'm goign to stop here -
please read the doc and correct throughout.
+
+ trigger_all_cpu_backtrace();
+ panic("Kernel Watchdog");
+
+ /* This code should not be reached */
+ return IRQ_HANDLED;
+}
+
+static int acpi_tco_add(struct acpi_device *device)
+{
+ acpi_status status;
+ unsigned long long tco_gpe;
Declare variables in decreasing line length order.
+
+ status = acpi_evaluate_integer(device->handle, "_GPE", NULL, &tco_gpe);
+ if (ACPI_FAILURE(status))
+ return -EINVAL;
+
+ status = acpi_install_gpe_handler(NULL, tco_gpe,
+ ACPI_GPE_EDGE_TRIGGERED,
+ warn_irq_handler, NULL);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ acpi_enable_gpe(NULL, tco_gpe);
+
+ pr_info("initialized. Interrupt=SCI GPE 0x%02llx", tco_gpe);
+ return 0;
+}
+
+static struct acpi_driver tco_driver = {
+ .name = "warn_int",
+ .class = TCO_CLASS,
+ .ids = tco_device_ids,
+ .ops = {
+ .add = acpi_tco_add,
+ },
+};
+
+static int __init warn_int_init(void)
+{
+ return acpi_bus_register_driver(&tco_driver);
+}
+
+module_init(warn_int_init);
+/* no module_exit, this driver shouldn't be unloaded */
+
+MODULE_AUTHOR("Francois-Nicolas Muller <francois-nicolas.muller@xxxxxxxxx>");
+MODULE_DESCRIPTION("Intel TCO WatchDog Warning Interrupt");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
--
1.7.9.5
