From: Fu Wei <[email protected]>
This patchset:
(1)Introduce Documentation/devicetree/bindings/watchdog/sbsa-gwdt.txt
for FDT info of SBSA Generic Watchdog, and give two examples of
adding SBSA Generic Watchdog device node into the dts files:
foundation-v8.dts and amd-seattle-soc.dtsi.
(2)Introduce "pretimeout" into the watchdog framework, and update
Documentation/watchdog/watchdog-kernel-api.txt to introduce:
(1)the new elements in the watchdog_device and watchdog_ops struct;
(2)the new API "watchdog_init_timeouts".
(3)Introduce ARM SBSA watchdog driver:
a.Use linux kernel watchdog framework;
b.Work with FDT on ARM64;
c.Use "pretimeout" in watchdog framework;
d.In first timeout, do panic to save system context;
e.Support getting timeout and pretimeout from parameter and FDT
at the driver init stage.
(4)Parse SBSA Generic Watchdog Structure in GTDT table of ACPI,
and create a platform device with that information.
This platform device can be used by This Watchdog driver.
This patchset has been tested with watchdog daemon
(ACPI/FDT, module/build-in) on the following platforms:
(1)ARM Foundation v8 model
(2)AMD Seattle B0
Changelog:
v3: Delete "export arch_timer_get_rate" patch.
Driver back to use arch_timer_get_cntfrq.
Improve watchdog_init_timeouts function and update relevant documentation.
Improve watchdog_timeout_invalid and watchdog_pretimeout_invalid.
Improve foundation-v8.dts: delete the unnecessary tag of device node.
Remove "ARM64 || COMPILE_TEST" from Kconfig.
Add comments in arch/arm64/kernel/acpi.c
Fix typoes and incorrect comments.
v2: Improve watchdog-kernel-api.txt documentation for pretimeout support.
Export "arch_timer_get_rate" in arm_arch_timer.c.
Add watchdog_init_timeouts API for pretimeout support in framework.
Improve suspend and resume foundation in driver
Improve timeout/pretimeout values init code in driver.
Delete unnecessary items of the sbsa_gwdt struct and #define.
Delete all unnecessary debug info in driver.
Fix 64bit division bug.
Use the arch_timer interface to get watchdog clock rate.
Add MODULE_DEVICE_TABLE for platform device id.
Fix typoes.
v1: The first version upstream patchset to linux mailing list.
Fu Wei (6):
Documentation: add sbsa-gwdt.txt documentation
ARM64: add SBSA Generic Watchdog device node in foundation-v8.dts
ARM64: add SBSA Generic Watchdog device node in amd-seattle-soc.dtsi
Watchdog: introdouce "pretimeout" into framework
Watchdog: introduce ARM SBSA watchdog driver
ACPI: import watchdog info of GTDT into platform device
.../devicetree/bindings/watchdog/sbsa-gwdt.txt | 36 ++
Documentation/watchdog/watchdog-kernel-api.txt | 47 +-
arch/arm64/boot/dts/amd/amd-seattle-soc.dtsi | 11 +
arch/arm64/boot/dts/arm/foundation-v8.dts | 10 +
arch/arm64/kernel/acpi.c | 145 +++++++
drivers/watchdog/Kconfig | 11 +
drivers/watchdog/Makefile | 1 +
drivers/watchdog/sbsa_gwdt.c | 474 +++++++++++++++++++++
drivers/watchdog/watchdog_core.c | 95 +++--
drivers/watchdog/watchdog_dev.c | 50 +++
include/linux/watchdog.h | 33 +-
11 files changed, 880 insertions(+), 33 deletions(-)
create mode 100644 Documentation/devicetree/bindings/watchdog/sbsa-gwdt.txt
create mode 100644 drivers/watchdog/sbsa_gwdt.c
--
1.9.1
From: Fu Wei <[email protected]>
The sbsa-gwdt.txt documentation in devicetree/bindings/watchdog is for
introducing SBSA(Server Base System Architecture) Generic Watchdog
device node info into FDT.
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Fu Wei <[email protected]>
---
.../devicetree/bindings/watchdog/sbsa-gwdt.txt | 36 ++++++++++++++++++++++
1 file changed, 36 insertions(+)
create mode 100644 Documentation/devicetree/bindings/watchdog/sbsa-gwdt.txt
diff --git a/Documentation/devicetree/bindings/watchdog/sbsa-gwdt.txt b/Documentation/devicetree/bindings/watchdog/sbsa-gwdt.txt
new file mode 100644
index 0000000..010e5c4
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/sbsa-gwdt.txt
@@ -0,0 +1,36 @@
+* SBSA(Server Base System Architecture) Generic Watchdog
+
+The SBSA Generic Watchdog Timer is used for resetting the system after
+two stages of timeout.
+More details: ARM-DEN-0029 - Server Base System Architecture (SBSA)
+
+Required properties:
+- compatible : Should at least contain "arm,sbsa-gwdt".
+
+- reg : base physical address of the frames and length of memory mapped region.
+
+- reg-names : Should contain the resource reg names to show the order of
+ the values in "reg".
+ Must include the following entries : "refresh", "control".
+
+- interrupts : Should at least contain WS0 interrupt,
+ the WS1 Signal is optional.
+
+- interrupt-names : Should contain the resource interrupt names.
+ Must include the following entries : "ws0". "ws1" is optional.
+
+Optional properties
+- timeout-sec : Watchdog pre-timeout and timeout values (in seconds).
+ The first is timeout values, then pre-timeout.
+
+Example for FVP Foundation Model v8:
+
+watchdog@2a440000 {
+ compatible = "arm,sbsa-gwdt";
+ reg = <0x0 0x2a440000 0 0x10000>,
+ <0x0 0x2a450000 0 0x10000>;
+ reg-names = "control", "refresh";
+ interrupts = <0 27 4>;
+ interrupt-names = "ws0";
+ timeout-sec = <10 5>;
+};
--
1.9.1
From: Fu Wei <[email protected]>
This can be a example of adding SBSA Generic Watchdog device node
into some dts files for the Soc which contains SBSA Generic Watchdog.
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Fu Wei <[email protected]>
---
arch/arm64/boot/dts/arm/foundation-v8.dts | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/arm64/boot/dts/arm/foundation-v8.dts b/arch/arm64/boot/dts/arm/foundation-v8.dts
index 4eac8dc..962a07e 100644
--- a/arch/arm64/boot/dts/arm/foundation-v8.dts
+++ b/arch/arm64/boot/dts/arm/foundation-v8.dts
@@ -237,4 +237,14 @@
};
};
};
+ watchdog@2a440000 {
+ compatible = "arm,sbsa-gwdt";
+ reg = <0x0 0x2a440000 0 0x10000>,
+ <0x0 0x2a450000 0 0x10000>;
+ reg-names = "control",
+ "refresh";
+ interrupts = <0 27 4>;
+ interrupt-names = "ws0";
+ timeout-sec = <10 5>;
+ };
};
--
1.9.1
From: Fu Wei <[email protected]>
This can be a example of adding SBSA Generic Watchdog device node
into some dts files for the Soc which contains SBSA Generic Watchdog.
Acked-by: Arnd Bergmann <[email protected]>
Acked-by: Suravee Suthikulpanit <[email protected]>
Tested-by: Suravee Suthikulpanit <[email protected]>
Signed-off-by: Fu Wei <[email protected]>
---
arch/arm64/boot/dts/amd/amd-seattle-soc.dtsi | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/arm64/boot/dts/amd/amd-seattle-soc.dtsi b/arch/arm64/boot/dts/amd/amd-seattle-soc.dtsi
index 2874d92..95994eb 100644
--- a/arch/arm64/boot/dts/amd/amd-seattle-soc.dtsi
+++ b/arch/arm64/boot/dts/amd/amd-seattle-soc.dtsi
@@ -84,6 +84,17 @@
clock-names = "uartclk", "apb_pclk";
};
+ watchdog0: watchdog@e0bb0000 {
+ compatible = "arm,sbsa-gwdt";
+ reg = <0x0 0xe0bb0000 0 0x10000>,
+ <0x0 0xe0bc0000 0 0x10000>;
+ reg-names = "refresh",
+ "control";
+ interrupts = <0 337 4>;
+ interrupt-names = "ws0";
+ timeout-sec = <10 5>;
+ };
+
spi0: ssp@e1020000 {
status = "disabled";
compatible = "arm,pl022", "arm,primecell";
--
1.9.1
From: Fu Wei <[email protected]>
Also update Documentation/watchdog/watchdog-kernel-api.txt to
introduce:
(1)the new elements in the watchdog_device and watchdog_ops struct;
(2)the new API "watchdog_init_timeouts"
Reasons:
(1)kernel already has two watchdog drivers are using "pretimeout":
drivers/char/ipmi/ipmi_watchdog.c
drivers/watchdog/kempld_wdt.c(but the definition is different)
(2)some other drivers are going to use this: ARM SBSA Generic Watchdog
Acked-by: Arnd Bergmann <[email protected]>
Tested-by: Suravee Suthikulpanit <[email protected]>
Signed-off-by: Fu Wei <[email protected]>
---
Documentation/watchdog/watchdog-kernel-api.txt | 47 +++++++++++--
drivers/watchdog/watchdog_core.c | 95 +++++++++++++++++++-------
drivers/watchdog/watchdog_dev.c | 50 ++++++++++++++
include/linux/watchdog.h | 33 ++++++++-
4 files changed, 192 insertions(+), 33 deletions(-)
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
index a0438f3..95b355d 100644
--- a/Documentation/watchdog/watchdog-kernel-api.txt
+++ b/Documentation/watchdog/watchdog-kernel-api.txt
@@ -49,6 +49,9 @@ struct watchdog_device {
unsigned int timeout;
unsigned int min_timeout;
unsigned int max_timeout;
+ unsigned int pretimeout;
+ unsigned int min_pretimeout;
+ unsigned int max_pretimeout;
void *driver_data;
struct mutex lock;
unsigned long status;
@@ -70,6 +73,9 @@ It contains following fields:
* timeout: the watchdog timer's timeout value (in seconds).
* min_timeout: the watchdog timer's minimum timeout value (in seconds).
* max_timeout: the watchdog timer's maximum timeout value (in seconds).
+* pretimeout: the watchdog timer's pretimeout value (in seconds).
+* min_pretimeout: the watchdog timer's minimum pretimeout value (in seconds).
+* max_pretimeout: the watchdog timer's maximum pretimeout value (in seconds).
* bootstatus: status of the device after booting (reported with watchdog
WDIOF_* status bits).
* driver_data: a pointer to the drivers private data of a watchdog device.
@@ -92,6 +98,7 @@ struct watchdog_ops {
int (*ping)(struct watchdog_device *);
unsigned int (*status)(struct watchdog_device *);
int (*set_timeout)(struct watchdog_device *, unsigned int);
+ int (*set_pretimeout)(struct watchdog_device *, unsigned int);
unsigned int (*get_timeleft)(struct watchdog_device *);
void (*ref)(struct watchdog_device *);
void (*unref)(struct watchdog_device *);
@@ -153,9 +160,19 @@ they are supported. These optional routines/operations are:
and -EIO for "could not write value to the watchdog". On success this
routine should set the timeout value of the watchdog_device to the
achieved timeout value (which may be different from the requested one
- because the watchdog does not necessarily has a 1 second resolution).
+ because the watchdog does not necessarily has a 1 second resolution;
+ If the driver supports pretimeout, then the timeout value must be greater
+ than that).
(Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the
watchdog's info structure).
+* set_pretimeout: this routine checks and changes the pretimeout of the
+ watchdog timer device. It returns 0 on success, -EINVAL for "parameter out of
+ range" and -EIO for "could not write value to the watchdog". On success this
+ routine should set the pretimeout value of the watchdog_device to the
+ achieved pretimeout value (which may be different from the requested one
+ because the watchdog does not necessarily has a 1 second resolution).
+ (Note: the WDIOF_PRETIMEOUT needs to be set in the options field of the
+ watchdog's info structure).
* get_timeleft: this routines returns the time that's left before a reset.
* ref: the operation that calls kref_get on the kref of a dynamically
allocated watchdog_device struct.
@@ -219,8 +236,28 @@ extern int watchdog_init_timeout(struct watchdog_device *wdd,
unsigned int timeout_parm, struct device *dev);
The watchdog_init_timeout function allows you to initialize the timeout field
-using the module timeout parameter or by retrieving the timeout-sec property from
-the device tree (if the module timeout parameter is invalid). Best practice is
-to set the default timeout value as timeout value in the watchdog_device and
-then use this function to set the user "preferred" timeout value.
+using the module timeout parameter or by retrieving the first element of
+the timeout-sec property from the device tree (if the module timeout parameter
+is invalid). Best practice is to set the default timeout value as timeout value
+in the watchdog_device and then use this function to set the user "preferred"
+timeout value.
+This routine returns zero on success and a negative errno code for failure.
+
+Some watchdog timers have two stage of timeouts(timeout and pretimeout),
+to initialize the timeout and pretimeout fields at the same time, the following
+function can be used:
+
+extern int watchdog_init_timeouts(struct watchdog_device *wdd,
+ unsigned int pretimeout_parm,
+ unsigned int timeout_parm,
+ struct device *dev);
+
+The watchdog_init_timeouts function allows you to initialize the pretimeout and
+timeout fields using the module pretimeout and timeout parameter or by
+retrieving the elements in the timeout-sec property(the first element is for
+timeout, the second one is for pretimeout) from the device tree(if the module
+pretimeout and timeout parameter are invalid).
+Best practice is to set the default pretimeout and timeout value as pretimeout
+and timeout value in the watchdog_device and then use this function to set the
+user "preferred" pretimeout value.
This routine returns zero on success and a negative errno code for failure.
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index cec9b55..85b1d33 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -43,60 +43,105 @@
static DEFINE_IDA(watchdog_ida);
static struct class *watchdog_class;
-static void watchdog_check_min_max_timeout(struct watchdog_device *wdd)
+static void watchdog_check_min_max_timeouts(struct watchdog_device *wdd)
{
/*
- * Check that we have valid min and max timeout values, if
- * not reset them both to 0 (=not used or unknown)
+ * Check that we have valid min and max pretimeout and timeout values,
+ * if not reset them both to 0 (=not used or unknown)
*/
+ if (wdd->min_pretimeout > wdd->max_pretimeout) {
+ pr_info("Invalid min and max pretimeout, resetting to 0\n");
+ wdd->min_pretimeout = 0;
+ wdd->max_pretimeout = 0;
+ }
if (wdd->min_timeout > wdd->max_timeout) {
pr_info("Invalid min and max timeout values, resetting to 0!\n");
wdd->min_timeout = 0;
wdd->max_timeout = 0;
}
+ /*
+ * Check that we have valid min and max timeout values,
+ * if not reset them both to pretimeout limits
+ */
+ if (wdd->min_pretimeout && wdd->min_timeout < wdd->min_pretimeout) {
+ pr_info("Invalid min timeout, resetting to min pretimeout\n");
+ wdd->min_timeout = wdd->min_pretimeout;
+ }
+ if (wdd->max_pretimeout && wdd->max_timeout < wdd->max_pretimeout) {
+ pr_info("Invalid max timeout, resetting to max pretimeout\n");
+ wdd->max_timeout = wdd->max_pretimeout;
+ }
}
/**
- * watchdog_init_timeout() - initialize the timeout field
+ * watchdog_init_timeouts() - initialize the pretimeout and timeout field
+ * @pretimeout_parm: pretimeout module parameter
* @timeout_parm: timeout module parameter
* @dev: Device that stores the timeout-sec property
*
- * Initialize the timeout field of the watchdog_device struct with either the
- * timeout module parameter (if it is valid value) or the timeout-sec property
- * (only if it is a valid value and the timeout_parm is out of bounds).
- * If none of them are valid then we keep the old value (which should normally
- * be the default timeout value.
+ * Initialize the pretimeout and timeout field of the watchdog_device struct
+ * with either the pretimeout and timeout module parameter (if it is valid
+ * value) or the timeout-sec property (only if it is a valid value and the
+ * pretimeout_parm and timeout_parm is out of bounds). If none of them are
+ * valid, then we keep the old value (which should normally be the default
+ * timeout value).
*
* A zero is returned on success and -EINVAL for failure.
*/
-int watchdog_init_timeout(struct watchdog_device *wdd,
- unsigned int timeout_parm, struct device *dev)
+int watchdog_init_timeouts(struct watchdog_device *wdd,
+ unsigned int pretimeout_parm,
+ unsigned int timeout_parm,
+ struct device *dev)
{
- unsigned int t = 0;
- int ret = 0;
+ u32 timeouts[2];
+ int ret = 0, length = 0;
- watchdog_check_min_max_timeout(wdd);
+ watchdog_check_min_max_timeouts(wdd);
- /* try to get the timeout module parameter first */
- if (!watchdog_timeout_invalid(wdd, timeout_parm) && timeout_parm) {
- wdd->timeout = timeout_parm;
- return ret;
+ /* try to get the timeout and pretimeout module parameter first */
+ if (pretimeout_parm) {
+ if (!watchdog_pretimeout_invalid(wdd, pretimeout_parm))
+ wdd->pretimeout = pretimeout_parm;
+ else
+ ret = -EINVAL;
}
- if (timeout_parm)
+
+ if (timeout_parm) {
+ if (!watchdog_timeout_invalid(wdd, timeout_parm)) {
+ wdd->timeout = timeout_parm;
+ return ret;
+ }
ret = -EINVAL;
+ }
/* try to get the timeout_sec property */
if (dev == NULL || dev->of_node == NULL)
return ret;
- of_property_read_u32(dev->of_node, "timeout-sec", &t);
- if (!watchdog_timeout_invalid(wdd, t) && t)
- wdd->timeout = t;
- else
+
+ of_find_property(dev->of_node, "timeout-sec", &length);
+ if (length > 0 && length <= sizeof(u32) * 2) {
+ of_property_read_u32_array(dev->of_node,
+ "timeout-sec", timeouts,
+ length / sizeof(u32));
+ if (length == 2) {
+ if (!watchdog_pretimeout_invalid(wdd, timeouts[1]) &&
+ timeouts[1])
+ wdd->pretimeout = timeouts[1];
+ else
+ ret = -EINVAL;
+ }
+
+ if (!watchdog_timeout_invalid(wdd, timeouts[0]) && timeouts[0])
+ wdd->timeout = timeouts[0];
+ else
+ ret = -EINVAL;
+ } else {
ret = -EINVAL;
+ }
return ret;
}
-EXPORT_SYMBOL_GPL(watchdog_init_timeout);
+EXPORT_SYMBOL_GPL(watchdog_init_timeouts);
/**
* watchdog_register_device() - register a watchdog device
@@ -119,7 +164,7 @@ int watchdog_register_device(struct watchdog_device *wdd)
if (wdd->ops->start == NULL || wdd->ops->stop == NULL)
return -EINVAL;
- watchdog_check_min_max_timeout(wdd);
+ watchdog_check_min_max_timeouts(wdd);
/*
* Note: now that all watchdog_device data has been verified, we
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 6aaefba..a65a9b0 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -218,6 +218,38 @@ out_timeout:
}
/*
+ * watchdog_set_pretimeout: set the watchdog timer pretimeout
+ * @wddev: the watchdog device to set the timeout for
+ * @pretimeout: pretimeout to set in seconds
+ */
+
+static int watchdog_set_pretimeout(struct watchdog_device *wddev,
+ unsigned int pretimeout)
+{
+ int err;
+
+ if (!wddev->ops->set_pretimeout ||
+ !(wddev->info->options & WDIOF_PRETIMEOUT))
+ return -EOPNOTSUPP;
+
+ if (watchdog_pretimeout_invalid(wddev, pretimeout))
+ return -EINVAL;
+
+ mutex_lock(&wddev->lock);
+
+ if (test_bit(WDOG_UNREGISTERED, &wddev->status)) {
+ err = -ENODEV;
+ goto out_pretimeout;
+ }
+
+ err = wddev->ops->set_pretimeout(wddev, pretimeout);
+
+out_pretimeout:
+ mutex_unlock(&wddev->lock);
+ return err;
+}
+
+/*
* watchdog_get_timeleft: wrapper to get the time left before a reboot
* @wddev: the watchdog device to get the remaining time from
* @timeleft: the time that's left
@@ -388,6 +420,24 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
if (wdd->timeout == 0)
return -EOPNOTSUPP;
return put_user(wdd->timeout, p);
+ case WDIOC_SETPRETIMEOUT:
+ if (get_user(val, p))
+ return -EFAULT;
+ err = watchdog_set_pretimeout(wdd, val);
+ if (err < 0)
+ return err;
+ /*
+ * If the watchdog is active then we send a keepalive ping
+ * to make sure that the watchdog keep's running (and if
+ * possible that it takes the new timeout)
+ */
+ watchdog_ping(wdd);
+ /* Fall */
+ case WDIOC_GETPRETIMEOUT:
+ /* pretimeout == 0 means that we don't know the pretimeout */
+ if (wdd->pretimeout == 0)
+ return -EOPNOTSUPP;
+ return put_user(wdd->pretimeout, p);
case WDIOC_GETTIMELEFT:
err = watchdog_get_timeleft(wdd, &val);
if (err)
diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index a746bf5..e776e1d 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -25,6 +25,7 @@ struct watchdog_device;
* @ping: The routine that sends a keepalive ping to the watchdog device.
* @status: The routine that shows the status of the watchdog device.
* @set_timeout:The routine for setting the watchdog devices timeout value.
+ * @set_pretimeout:The routine for setting the watchdog devices pretimeout value
* @get_timeleft:The routine that get's the time that's left before a reset.
* @ref: The ref operation for dyn. allocated watchdog_device structs
* @unref: The unref operation for dyn. allocated watchdog_device structs
@@ -44,6 +45,7 @@ struct watchdog_ops {
int (*ping)(struct watchdog_device *);
unsigned int (*status)(struct watchdog_device *);
int (*set_timeout)(struct watchdog_device *, unsigned int);
+ int (*set_pretimeout)(struct watchdog_device *, unsigned int);
unsigned int (*get_timeleft)(struct watchdog_device *);
void (*ref)(struct watchdog_device *);
void (*unref)(struct watchdog_device *);
@@ -62,6 +64,9 @@ struct watchdog_ops {
* @timeout: The watchdog devices timeout value.
* @min_timeout:The watchdog devices minimum timeout value.
* @max_timeout:The watchdog devices maximum timeout value.
+ * @pretimeout: The watchdog devices pretimeout value.
+ * @min_pretimeout:The watchdog devices minimum pretimeout value.
+ * @max_pretimeout:The watchdog devices maximum pretimeout value.
* @driver-data:Pointer to the drivers private data.
* @lock: Lock for watchdog core internal use only.
* @status: Field that contains the devices internal status bits.
@@ -86,6 +91,9 @@ struct watchdog_device {
unsigned int timeout;
unsigned int min_timeout;
unsigned int max_timeout;
+ unsigned int pretimeout;
+ unsigned int min_pretimeout;
+ unsigned int max_pretimeout;
void *driver_data;
struct mutex lock;
unsigned long status;
@@ -117,7 +125,17 @@ static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool noway
static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t)
{
return ((wdd->max_timeout != 0) &&
- (t < wdd->min_timeout || t > wdd->max_timeout));
+ (t < wdd->min_timeout || t > wdd->max_timeout ||
+ t < wdd->pretimeout));
+}
+
+/* Use the following function to check if a pretimeout value is invalid */
+static inline bool watchdog_pretimeout_invalid(struct watchdog_device *wdd,
+ unsigned int t)
+{
+ return (wdd->max_pretimeout != 0 &&
+ (t < wdd->min_pretimeout || t > wdd->max_pretimeout ||
+ (wdd->timeout != 0 && t > wdd->timeout)));
}
/* Use the following functions to manipulate watchdog driver specific data */
@@ -132,11 +150,20 @@ static inline void *watchdog_get_drvdata(struct watchdog_device *wdd)
}
/* drivers/watchdog/watchdog_core.c */
-extern int watchdog_init_timeout(struct watchdog_device *wdd,
- unsigned int timeout_parm, struct device *dev);
+extern int watchdog_init_timeouts(struct watchdog_device *wdd,
+ unsigned int pretimeout_parm,
+ unsigned int timeout_parm,
+ struct device *dev);
extern int watchdog_register_device(struct watchdog_device *);
extern void watchdog_unregister_device(struct watchdog_device *);
+static inline int watchdog_init_timeout(struct watchdog_device *wdd,
+ unsigned int timeout_parm,
+ struct device *dev)
+{
+ return watchdog_init_timeouts(wdd, 0, timeout_parm, dev);
+}
+
#ifdef CONFIG_HARDLOCKUP_DETECTOR
void watchdog_nmi_disable_all(void);
void watchdog_nmi_enable_all(void);
--
1.9.1
From: Fu Wei <[email protected]>
This driver bases on linux kernel watchdog framework, and
use "pretimeout" in the framework. It supports getting timeout and
pretimeout from parameter and FDT at the driver init stage.
In first timeout, the interrupt routine run panic to save
system context.
Acked-by: Arnd Bergmann <[email protected]>
Tested-by: Suravee Suthikulpanit <[email protected]>
Signed-off-by: Fu Wei <[email protected]>
---
drivers/watchdog/Kconfig | 11 +
drivers/watchdog/Makefile | 1 +
drivers/watchdog/sbsa_gwdt.c | 474 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 486 insertions(+)
create mode 100644 drivers/watchdog/sbsa_gwdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index e5e7c55..554f18a 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -152,6 +152,17 @@ config ARM_SP805_WATCHDOG
ARM Primecell SP805 Watchdog timer. This will reboot your system when
the timeout is reached.
+config ARM_SBSA_WATCHDOG
+ tristate "ARM SBSA Generic Watchdog"
+ depends on ARM64
+ depends on ARM_ARCH_TIMER
+ select WATCHDOG_CORE
+ help
+ ARM SBSA Generic Watchdog. This watchdog has two Watchdog timeouts.
+ The first timeout will trigger a panic; the second timeout will
+ trigger a system reset.
+ More details: ARM DEN0029B - Server Base System Architecture (SBSA)
+
config AT91RM9200_WATCHDOG
tristate "AT91RM9200 watchdog"
depends on SOC_AT91RM9200 && MFD_SYSCON
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 5c19294..471f1b7c 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb.o
# ARM Architecture
obj-$(CONFIG_ARM_SP805_WATCHDOG) += sp805_wdt.o
+obj-$(CONFIG_ARM_SBSA_WATCHDOG) += sbsa_gwdt.o
obj-$(CONFIG_AT91RM9200_WATCHDOG) += at91rm9200_wdt.o
obj-$(CONFIG_AT91SAM9X_WATCHDOG) += at91sam9_wdt.o
obj-$(CONFIG_CADENCE_WATCHDOG) += cadence_wdt.o
diff --git a/drivers/watchdog/sbsa_gwdt.c b/drivers/watchdog/sbsa_gwdt.c
new file mode 100644
index 0000000..0d1aff1
--- /dev/null
+++ b/drivers/watchdog/sbsa_gwdt.c
@@ -0,0 +1,474 @@
+/*
+ * SBSA(Server Base System Architecture) Generic Watchdog driver
+ *
+ * Copyright (c) 2015, Linaro Ltd.
+ * Author: Fu Wei <[email protected]>
+ * Suravee Suthikulpanit <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 2 as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ * Note: This SBSA Generic watchdog driver is compatible with
+ * the pretimeout concept of Linux kernel.
+ * The timeout and pretimeout are set by the different REGs.
+ * The first watch period is set by writing WCV directly,
+ * that can support more than 10s timeout at the maximum
+ * system counter frequency.
+ * The second watch period is set by WOR(32bit) which will be loaded
+ * automatically by hardware, when WS0 is triggered.
+ * This gives a maximum watch period of around 10s at the maximum
+ * system counter frequency.
+ * The System Counter shall run at maximum of 400MHz.
+ * More details: ARM DEN0029B - Server Base System Architecture (SBSA)
+ *
+ * Kernel/API: P---------| pretimeout
+ * |-------------------------------T timeout
+ * SBSA GWDT: P--WOR---WS1 pretimeout
+ * |-------WCV----------WS0~~~~~~~~T timeout
+ */
+
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+#include <asm/arch_timer.h>
+
+/* SBSA Generic Watchdog register definitions */
+/* refresh frame */
+#define SBSA_GWDT_WRR 0x000
+
+/* control frame */
+#define SBSA_GWDT_WCS 0x000
+#define SBSA_GWDT_WOR 0x008
+#define SBSA_GWDT_WCV_LO 0x010
+#define SBSA_GWDT_WCV_HI 0x014
+
+/* refresh/control frame */
+#define SBSA_GWDT_W_IIDR 0xfcc
+#define SBSA_GWDT_IDR 0xfd0
+
+/* Watchdog Control and Status Register */
+#define SBSA_GWDT_WCS_EN BIT(0)
+#define SBSA_GWDT_WCS_WS0 BIT(1)
+#define SBSA_GWDT_WCS_WS1 BIT(2)
+
+/**
+ * struct sbsa_gwdt - Internal representation of the SBSA GWDT
+ * @wdd: kernel watchdog_device structure
+ * @clk: store the System Counter clock frequency, in Hz.
+ * @refresh_base: Virtual address of the watchdog refresh frame
+ * @control_base: Virtual address of the watchdog control frame
+ */
+struct sbsa_gwdt {
+ struct watchdog_device wdd;
+ u32 clk;
+ void __iomem *refresh_base;
+ void __iomem *control_base;
+};
+
+#define to_sbsa_gwdt(e) container_of(e, struct sbsa_gwdt, wdd)
+
+#define DEFAULT_TIMEOUT 10 /* seconds, the 1st + 2nd watch periods*/
+#define DEFAULT_PRETIMEOUT 5 /* seconds, the 2nd watch period*/
+
+static unsigned int timeout_param;
+module_param(timeout_param, uint, 0);
+MODULE_PARM_DESC(timeout_param,
+ "Watchdog timeout in seconds. (>=0, default="
+ __MODULE_STRING(DEFAULT_TIMEOUT) ")");
+
+static unsigned int max_timeout_param = UINT_MAX;
+module_param(max_timeout_param, uint, 0);
+MODULE_PARM_DESC(max_timeout_param,
+ "Watchdog max timeout in seconds. (>=0, default="
+ __MODULE_STRING(UINT_MAX) ")");
+
+static unsigned int pretimeout_param;
+module_param(pretimeout_param, uint, 0);
+MODULE_PARM_DESC(pretimeout_param,
+ "Watchdog pretimeout in seconds. (>=0, default="
+ __MODULE_STRING(DEFAULT_PRETIMEOUT) ")");
+
+static unsigned int max_pretimeout_param = U32_MAX;
+module_param(max_pretimeout_param, uint, 0);
+MODULE_PARM_DESC(max_pretimeout_param,
+ "Watchdog max pretimeout in seconds. (>=0, default="
+ __MODULE_STRING(U32_MAX) ")");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, S_IRUGO);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+/*
+ * help functions for accessing 32bit registers of SBSA Generic Watchdog
+ */
+static void sbsa_gwdt_cf_write(unsigned int reg, u32 val,
+ struct watchdog_device *wdd)
+{
+ struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
+
+ writel_relaxed(val, gwdt->control_base + reg);
+}
+
+static void sbsa_gwdt_rf_write(unsigned int reg, u32 val,
+ struct watchdog_device *wdd)
+{
+ struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
+
+ writel_relaxed(val, gwdt->refresh_base + reg);
+}
+
+static u32 sbsa_gwdt_cf_read(unsigned int reg, struct watchdog_device *wdd)
+{
+ struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
+
+ return readl_relaxed(gwdt->control_base + reg);
+}
+
+/*
+ * help functions for accessing 64bit WCV register
+ */
+static u64 sbsa_gwdt_get_wcv(struct watchdog_device *wdd)
+{
+ u32 wcv_lo, wcv_hi;
+
+ do {
+ wcv_hi = sbsa_gwdt_cf_read(SBSA_GWDT_WCV_HI, wdd);
+ wcv_lo = sbsa_gwdt_cf_read(SBSA_GWDT_WCV_LO, wdd);
+ } while (wcv_hi != sbsa_gwdt_cf_read(SBSA_GWDT_WCV_HI, wdd));
+
+ return (((u64)wcv_hi << 32) | wcv_lo);
+}
+
+static void sbsa_gwdt_set_wcv(struct watchdog_device *wdd, u64 value)
+{
+ u32 wcv_lo, wcv_hi;
+
+ wcv_lo = value & U32_MAX;
+ wcv_hi = (value >> 32) & U32_MAX;
+
+ sbsa_gwdt_cf_write(SBSA_GWDT_WCV_HI, wcv_hi, wdd);
+ sbsa_gwdt_cf_write(SBSA_GWDT_WCV_LO, wcv_lo, wdd);
+}
+
+static void reload_timeout_to_wcv(struct watchdog_device *wdd)
+{
+ struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
+ u64 wcv;
+
+ wcv = arch_counter_get_cntvct() +
+ (u64)(wdd->timeout - wdd->pretimeout) * gwdt->clk;
+
+ sbsa_gwdt_set_wcv(wdd, wcv);
+}
+
+/*
+ * Use the following function to update the timeout limits
+ * after updating pretimeout
+ */
+static void sbsa_gwdt_update_limits(struct watchdog_device *wdd)
+{
+ struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
+ u64 first_period_max = U64_MAX;
+
+ do_div(first_period_max, gwdt->clk);
+
+ wdd->min_timeout = wdd->pretimeout + 1;
+ wdd->max_timeout = min((uint)(wdd->pretimeout + first_period_max),
+ wdd->max_timeout);
+}
+
+static int sbsa_gwdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ wdd->timeout = timeout;
+
+ return 0;
+}
+
+static int sbsa_gwdt_set_pretimeout(struct watchdog_device *wdd,
+ unsigned int pretimeout)
+{
+ struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
+ u32 wor;
+
+ wdd->pretimeout = pretimeout;
+ sbsa_gwdt_update_limits(wdd);
+
+ if (!pretimeout)
+ /* gives sbsa_gwdt_start a chance to setup timeout */
+ wor = gwdt->clk;
+ else
+ wor = pretimeout * gwdt->clk;
+
+ /* refresh the WOR, that will cause an explicit watchdog refresh */
+ sbsa_gwdt_cf_write(SBSA_GWDT_WOR, wor, wdd);
+
+ return 0;
+}
+
+static unsigned int sbsa_gwdt_get_timeleft(struct watchdog_device *wdd)
+{
+ struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
+ u64 timeleft = sbsa_gwdt_get_wcv(wdd) - arch_counter_get_cntvct();
+
+ do_div(timeleft, gwdt->clk);
+
+ return timeleft;
+}
+
+static int sbsa_gwdt_start(struct watchdog_device *wdd)
+{
+ /* Force refresh */
+ sbsa_gwdt_rf_write(SBSA_GWDT_WRR, 0xc0ffee, wdd);
+ /* writing WCS will cause an explicit watchdog refresh */
+ sbsa_gwdt_cf_write(SBSA_GWDT_WCS, SBSA_GWDT_WCS_EN, wdd);
+
+ reload_timeout_to_wcv(wdd);
+
+ return 0;
+}
+
+static int sbsa_gwdt_stop(struct watchdog_device *wdd)
+{
+ /* Force refresh */
+ sbsa_gwdt_rf_write(SBSA_GWDT_WRR, 0xc0ffee, wdd);
+ /* writing WCS will cause an explicit watchdog refresh */
+ sbsa_gwdt_cf_write(SBSA_GWDT_WCS, 0, wdd);
+
+ return 0;
+}
+
+static int sbsa_gwdt_keepalive(struct watchdog_device *wdd)
+{
+ /*
+ * Writing WRR for an explicit watchdog refresh
+ * You can write anyting(like 0xc0ffee)
+ */
+ sbsa_gwdt_rf_write(SBSA_GWDT_WRR, 0xc0ffee, wdd);
+
+ reload_timeout_to_wcv(wdd);
+
+ return 0;
+}
+
+static irqreturn_t sbsa_gwdt_interrupt(int irq, void *dev_id)
+{
+ struct sbsa_gwdt *gwdt = (struct sbsa_gwdt *)dev_id;
+ struct watchdog_device *wdd = &gwdt->wdd;
+ u32 status;
+
+ status = sbsa_gwdt_cf_read(SBSA_GWDT_WCS, wdd);
+
+ if (status & SBSA_GWDT_WCS_WS0)
+ panic("SBSA Watchdog pre-timeout");
+
+ return IRQ_HANDLED;
+}
+
+static struct watchdog_info sbsa_gwdt_info = {
+ .identity = "SBSA Generic Watchdog",
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE |
+ WDIOF_PRETIMEOUT |
+ WDIOF_CARDRESET,
+};
+
+static struct watchdog_ops sbsa_gwdt_ops = {
+ .owner = THIS_MODULE,
+ .start = sbsa_gwdt_start,
+ .stop = sbsa_gwdt_stop,
+ .ping = sbsa_gwdt_keepalive,
+ .set_timeout = sbsa_gwdt_set_timeout,
+ .set_pretimeout = sbsa_gwdt_set_pretimeout,
+ .get_timeleft = sbsa_gwdt_get_timeleft,
+};
+
+static int sbsa_gwdt_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct sbsa_gwdt *gwdt;
+ struct watchdog_device *wdd;
+ struct resource *res;
+ void *rf_base, *cf_base;
+ int irq;
+ u32 clk, status;
+ int ret = 0;
+ u64 first_period_max = U64_MAX;
+
+ /*
+ * Get the frequency of system counter from
+ * the cp15 interface of ARM Generic timer
+ */
+ clk = arch_timer_get_cntfrq();
+ if (!clk) {
+ dev_err(dev, "System Counter frequency not available\n");
+ return -EINVAL;
+ }
+
+ gwdt = devm_kzalloc(dev, sizeof(*gwdt), GFP_KERNEL);
+ if (!gwdt)
+ return -ENOMEM;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "refresh");
+ rf_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(rf_base))
+ return PTR_ERR(rf_base);
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "control");
+ cf_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(cf_base))
+ return PTR_ERR(cf_base);
+
+ irq = platform_get_irq_byname(pdev, "ws0");
+ if (irq < 0) {
+ dev_err(dev, "unable to get ws0 interrupt.\n");
+ return irq;
+ }
+
+ gwdt->refresh_base = rf_base;
+ gwdt->control_base = cf_base;
+ gwdt->clk = clk;
+
+ platform_set_drvdata(pdev, gwdt);
+
+ wdd = &gwdt->wdd;
+ wdd->parent = dev;
+ wdd->info = &sbsa_gwdt_info;
+ wdd->ops = &sbsa_gwdt_ops;
+ watchdog_set_drvdata(wdd, gwdt);
+ watchdog_set_nowayout(wdd, nowayout);
+
+ status = sbsa_gwdt_cf_read(SBSA_GWDT_WCS, wdd);
+ if (status & SBSA_GWDT_WCS_WS1) {
+ dev_warn(dev, "System reset by WDT(WCS: %x, WCV: %llx)\n",
+ status, sbsa_gwdt_get_wcv(wdd));
+ wdd->bootstatus |= WDIOF_CARDRESET;
+ }
+ /* Check if watchdog is already enabled */
+ if (status & SBSA_GWDT_WCS_EN) {
+ dev_warn(dev, "already enabled! WCS:0x%x\n", status);
+ sbsa_gwdt_keepalive(wdd);
+ }
+
+ wdd->min_pretimeout = 0;
+ wdd->max_pretimeout = min(U32_MAX / clk, max_pretimeout_param);
+ wdd->min_timeout = 1;
+ do_div(first_period_max, clk);
+ wdd->max_timeout = min((uint)(wdd->pretimeout + first_period_max),
+ max_timeout_param);
+
+ wdd->pretimeout = DEFAULT_PRETIMEOUT;
+ wdd->timeout = DEFAULT_TIMEOUT;
+ watchdog_init_timeouts(wdd, pretimeout_param, timeout_param, dev);
+ /* update pretimeout to WOR */
+ sbsa_gwdt_cf_write(SBSA_GWDT_WOR, wdd->pretimeout * clk, wdd);
+
+ ret = devm_request_irq(dev, irq, sbsa_gwdt_interrupt, IRQF_TIMER,
+ pdev->name, gwdt);
+ if (ret) {
+ dev_err(dev, "unable to request IRQ %d\n", irq);
+ return ret;
+ }
+
+ ret = watchdog_register_device(wdd);
+ if (ret)
+ return ret;
+
+ dev_info(dev, "Initialized with %ds timeout, %ds pretimeout @ %uHz\n",
+ wdd->timeout, wdd->pretimeout, gwdt->clk);
+
+ return 0;
+}
+
+static void sbsa_gwdt_shutdown(struct platform_device *pdev)
+{
+ struct sbsa_gwdt *gwdt = platform_get_drvdata(pdev);
+
+ sbsa_gwdt_stop(&gwdt->wdd);
+}
+
+static int sbsa_gwdt_remove(struct platform_device *pdev)
+{
+ struct sbsa_gwdt *gwdt = platform_get_drvdata(pdev);
+ int ret = 0;
+
+ if (!nowayout)
+ ret = sbsa_gwdt_stop(&gwdt->wdd);
+
+ watchdog_unregister_device(&gwdt->wdd);
+
+ return ret;
+}
+
+/* Disable watchdog if it is active during suspend */
+static int __maybe_unused sbsa_gwdt_suspend(struct device *dev)
+{
+ struct sbsa_gwdt *gwdt = dev_get_drvdata(dev);
+
+ if (watchdog_active(&gwdt->wdd))
+ sbsa_gwdt_stop(&gwdt->wdd);
+
+ return 0;
+}
+
+/* Enable watchdog and configure it if necessary */
+static int __maybe_unused sbsa_gwdt_resume(struct device *dev)
+{
+ struct sbsa_gwdt *gwdt = dev_get_drvdata(dev);
+
+ if (watchdog_active(&gwdt->wdd))
+ sbsa_gwdt_start(&gwdt->wdd);
+
+ return 0;
+}
+
+static const struct dev_pm_ops sbsa_gwdt_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(sbsa_gwdt_suspend, sbsa_gwdt_resume)
+};
+
+static const struct of_device_id sbsa_gwdt_of_match[] = {
+ { .compatible = "arm,sbsa-gwdt", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, sbsa_gwdt_of_match);
+
+static const struct platform_device_id sbsa_gwdt_pdev_match[] = {
+ { .name = "sbsa-gwdt", },
+ {},
+};
+MODULE_DEVICE_TABLE(platform, sbsa_gwdt_pdev_match);
+
+static struct platform_driver sbsa_gwdt_driver = {
+ .driver = {
+ .name = "sbsa-gwdt",
+ .pm = &sbsa_gwdt_pm_ops,
+ .of_match_table = sbsa_gwdt_of_match,
+ },
+ .probe = sbsa_gwdt_probe,
+ .remove = sbsa_gwdt_remove,
+ .shutdown = sbsa_gwdt_shutdown,
+ .id_table = sbsa_gwdt_pdev_match,
+};
+
+module_platform_driver(sbsa_gwdt_driver);
+
+MODULE_DESCRIPTION("SBSA Generic Watchdog Driver");
+MODULE_VERSION("v1.0");
+MODULE_AUTHOR("Fu Wei <[email protected]>");
+MODULE_AUTHOR("Suravee Suthikulpanit <[email protected]>");
+MODULE_LICENSE("GPL v2");
--
1.9.1
From: Fu Wei <[email protected]>
Parse SBSA Generic Watchdog Structure in GTDT table of ACPI,
and create a platform device with that information.
This platform device can be used by the ARM SBSA Generic
Watchdog driver.
Tested-by: Suravee Suthikulpanit <[email protected]>
Tested-by: Timur Tabi <[email protected]>
Signed-off-by: Fu Wei <[email protected]>
---
arch/arm64/kernel/acpi.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 145 insertions(+)
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index 8b83955..c95deec 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -23,6 +23,7 @@
#include <linux/irqdomain.h>
#include <linux/memblock.h>
#include <linux/of_fdt.h>
+#include <linux/platform_device.h>
#include <linux/smp.h>
#include <asm/cputype.h>
@@ -343,3 +344,147 @@ void __init acpi_gic_init(void)
early_acpi_os_unmap_memory((char *)table, tbl_size);
}
+
+static int __init acpi_gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd,
+ int index)
+{
+ struct platform_device *pdev;
+ struct resource *res;
+ u32 gsi, flags;
+ int irq, trigger, polarity;
+ resource_size_t rf_base_phy, cf_base_phy;
+ int err = -ENOMEM;
+
+ /*
+ * Get SBSA Generic Watchdog info
+ * from a Watchdog GT type structure in GTDT
+ */
+ rf_base_phy = (resource_size_t)wd->refresh_frame_address;
+ cf_base_phy = (resource_size_t)wd->control_frame_address;
+ gsi = wd->timer_interrupt;
+ flags = wd->timer_flags;
+
+ pr_debug("GTDT: a Watchdog GT structure(0x%llx/0x%llx gsi:%u flags:0x%x)\n",
+ rf_base_phy, cf_base_phy, gsi, flags);
+
+ if (!(rf_base_phy && cf_base_phy && gsi)) {
+ pr_err("GTDT: failed geting the device info.\n");
+ return -EINVAL;
+ }
+
+ trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
+ : ACPI_LEVEL_SENSITIVE;
+ polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
+ : ACPI_ACTIVE_HIGH;
+ irq = acpi_register_gsi(NULL, gsi, trigger, polarity);
+ if (irq < 0) {
+ pr_err("GTDT: failed to register GSI of the Watchdog GT.\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Add a platform device named "sbsa-gwdt" to match the platform driver.
+ * "sbsa-gwdt": SBSA(Server Base System Architecture) Generic Watchdog
+ * The platform driver can get device info below by matching this name.
+ */
+ pdev = platform_device_alloc("sbsa-gwdt", index);
+ if (!pdev)
+ goto err_unregister_gsi;
+
+ res = kcalloc(3, sizeof(*res), GFP_KERNEL);
+ if (!res)
+ goto err_device_put;
+
+ /*
+ * According to SBSA specification the size of refresh and control
+ * frames of SBSA Generic Watchdog is SZ_4K(Offset 0x000 – 0xFFF).
+ */
+ res[0].start = rf_base_phy;
+ res[0].end = rf_base_phy + SZ_4K - 1;
+ res[0].name = "refresh";
+ res[0].flags = IORESOURCE_MEM;
+
+ res[1].start = cf_base_phy;
+ res[1].end = cf_base_phy + SZ_4K - 1;
+ res[1].name = "control";
+ res[1].flags = IORESOURCE_MEM;
+
+ res[2].start = irq;
+ res[2].end = res[2].start;
+ res[2].name = "ws0";
+ res[2].flags = IORESOURCE_IRQ;
+
+ err = platform_device_add_resources(pdev, res, 3);
+ if (err)
+ goto err_free_res;
+
+ err = platform_device_add(pdev);
+ if (err)
+ goto err_free_res;
+
+ return 0;
+
+err_free_res:
+ kfree(res);
+err_device_put:
+ platform_device_put(pdev);
+err_unregister_gsi:
+ acpi_unregister_gsi(gsi);
+
+ return err;
+}
+
+/* Initialize SBSA generic Watchdog platform device info from GTDT */
+static int __init acpi_gtdt_sbsa_gwdt_init(struct acpi_table_header *table)
+{
+ struct acpi_table_gtdt *gtdt;
+ struct acpi_gtdt_header *header;
+ void *gtdt_subtable;
+ int i, gwdt_index;
+ int ret = 0;
+
+ if (table->revision < 2) {
+ pr_warn("GTDT: Revision:%d doesn't support Platform Timers.\n",
+ table->revision);
+ return 0;
+ }
+
+ gtdt = container_of(table, struct acpi_table_gtdt, header);
+ if (!gtdt->platform_timer_count) {
+ pr_info("GTDT: No Platform Timer structures.\n");
+ return 0;
+ }
+
+ gtdt_subtable = (void *)gtdt + gtdt->platform_timer_offset;
+
+ for (i = 0, gwdt_index = 0; i < gtdt->platform_timer_count; i++) {
+ if (gtdt_subtable > (void *)table + table->length) {
+ pr_err("GTDT: subtable pointer overflows, bad table\n");
+ return -EINVAL;
+ }
+ header = (struct acpi_gtdt_header *)gtdt_subtable;
+ if (header->type == ACPI_GTDT_TYPE_WATCHDOG) {
+ ret = acpi_gtdt_import_sbsa_gwdt(gtdt_subtable,
+ gwdt_index);
+ if (ret)
+ pr_err("GTDT: failed to import subtable %d\n",
+ i);
+ else
+ gwdt_index++;
+ }
+ gtdt_subtable += header->length;
+ }
+
+ return ret;
+}
+
+/* Initialize the SBSA Generic Watchdog presented in GTDT */
+static int __init acpi_gtdt_init(void)
+{
+ if (acpi_disabled)
+ return 0;
+
+ return acpi_table_parse(ACPI_SIG_GTDT, acpi_gtdt_sbsa_gwdt_init);
+}
+
+arch_initcall(acpi_gtdt_init);
--
1.9.1
On 05/25/2015 03:03 AM, [email protected] wrote:
> From: Fu Wei <[email protected]>
>
> Also update Documentation/watchdog/watchdog-kernel-api.txt to
> introduce:
> (1)the new elements in the watchdog_device and watchdog_ops struct;
> (2)the new API "watchdog_init_timeouts"
>
> Reasons:
> (1)kernel already has two watchdog drivers are using "pretimeout":
> drivers/char/ipmi/ipmi_watchdog.c
> drivers/watchdog/kempld_wdt.c(but the definition is different)
> (2)some other drivers are going to use this: ARM SBSA Generic Watchdog
>
> Acked-by: Arnd Bergmann <[email protected]>
> Tested-by: Suravee Suthikulpanit <[email protected]>
> Signed-off-by: Fu Wei <[email protected]>
> ---
Comments inline.
Thanks,
Guenter
> Documentation/watchdog/watchdog-kernel-api.txt | 47 +++++++++++--
> drivers/watchdog/watchdog_core.c | 95 +++++++++++++++++++-------
> drivers/watchdog/watchdog_dev.c | 50 ++++++++++++++
> include/linux/watchdog.h | 33 ++++++++-
> 4 files changed, 192 insertions(+), 33 deletions(-)
>
> diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
> index a0438f3..95b355d 100644
> --- a/Documentation/watchdog/watchdog-kernel-api.txt
> +++ b/Documentation/watchdog/watchdog-kernel-api.txt
> @@ -49,6 +49,9 @@ struct watchdog_device {
> unsigned int timeout;
> unsigned int min_timeout;
> unsigned int max_timeout;
> + unsigned int pretimeout;
> + unsigned int min_pretimeout;
> + unsigned int max_pretimeout;
> void *driver_data;
> struct mutex lock;
> unsigned long status;
> @@ -70,6 +73,9 @@ It contains following fields:
> * timeout: the watchdog timer's timeout value (in seconds).
> * min_timeout: the watchdog timer's minimum timeout value (in seconds).
> * max_timeout: the watchdog timer's maximum timeout value (in seconds).
> +* pretimeout: the watchdog timer's pretimeout value (in seconds).
> +* min_pretimeout: the watchdog timer's minimum pretimeout value (in seconds).
> +* max_pretimeout: the watchdog timer's maximum pretimeout value (in seconds).
> * bootstatus: status of the device after booting (reported with watchdog
> WDIOF_* status bits).
> * driver_data: a pointer to the drivers private data of a watchdog device.
> @@ -92,6 +98,7 @@ struct watchdog_ops {
> int (*ping)(struct watchdog_device *);
> unsigned int (*status)(struct watchdog_device *);
> int (*set_timeout)(struct watchdog_device *, unsigned int);
> + int (*set_pretimeout)(struct watchdog_device *, unsigned int);
> unsigned int (*get_timeleft)(struct watchdog_device *);
> void (*ref)(struct watchdog_device *);
> void (*unref)(struct watchdog_device *);
> @@ -153,9 +160,19 @@ they are supported. These optional routines/operations are:
> and -EIO for "could not write value to the watchdog". On success this
> routine should set the timeout value of the watchdog_device to the
> achieved timeout value (which may be different from the requested one
> - because the watchdog does not necessarily has a 1 second resolution).
> + because the watchdog does not necessarily has a 1 second resolution;
> + If the driver supports pretimeout, then the timeout value must be greater
> + than that).
> (Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the
> watchdog's info structure).
> +* set_pretimeout: this routine checks and changes the pretimeout of the
> + watchdog timer device. It returns 0 on success, -EINVAL for "parameter out of
> + range" and -EIO for "could not write value to the watchdog". On success this
> + routine should set the pretimeout value of the watchdog_device to the
> + achieved pretimeout value (which may be different from the requested one
> + because the watchdog does not necessarily has a 1 second resolution).
> + (Note: the WDIOF_PRETIMEOUT needs to be set in the options field of the
> + watchdog's info structure).
> * get_timeleft: this routines returns the time that's left before a reset.
> * ref: the operation that calls kref_get on the kref of a dynamically
> allocated watchdog_device struct.
> @@ -219,8 +236,28 @@ extern int watchdog_init_timeout(struct watchdog_device *wdd,
> unsigned int timeout_parm, struct device *dev);
>
> The watchdog_init_timeout function allows you to initialize the timeout field
> -using the module timeout parameter or by retrieving the timeout-sec property from
> -the device tree (if the module timeout parameter is invalid). Best practice is
> -to set the default timeout value as timeout value in the watchdog_device and
> -then use this function to set the user "preferred" timeout value.
> +using the module timeout parameter or by retrieving the first element of
> +the timeout-sec property from the device tree (if the module timeout parameter
> +is invalid). Best practice is to set the default timeout value as timeout value
> +in the watchdog_device and then use this function to set the user "preferred"
> +timeout value.
> +This routine returns zero on success and a negative errno code for failure.
> +
> +Some watchdog timers have two stage of timeouts(timeout and pretimeout),
> +to initialize the timeout and pretimeout fields at the same time, the following
> +function can be used:
> +
> +extern int watchdog_init_timeouts(struct watchdog_device *wdd,
> + unsigned int pretimeout_parm,
> + unsigned int timeout_parm,
> + struct device *dev);
> +
> +The watchdog_init_timeouts function allows you to initialize the pretimeout and
> +timeout fields using the module pretimeout and timeout parameter or by
> +retrieving the elements in the timeout-sec property(the first element is for
> +timeout, the second one is for pretimeout) from the device tree(if the module
> +pretimeout and timeout parameter are invalid).
> +Best practice is to set the default pretimeout and timeout value as pretimeout
> +and timeout value in the watchdog_device and then use this function to set the
> +user "preferred" pretimeout value.
> This routine returns zero on success and a negative errno code for failure.
> diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
> index cec9b55..85b1d33 100644
> --- a/drivers/watchdog/watchdog_core.c
> +++ b/drivers/watchdog/watchdog_core.c
> @@ -43,60 +43,105 @@
> static DEFINE_IDA(watchdog_ida);
> static struct class *watchdog_class;
>
> -static void watchdog_check_min_max_timeout(struct watchdog_device *wdd)
> +static void watchdog_check_min_max_timeouts(struct watchdog_device *wdd)
> {
> /*
> - * Check that we have valid min and max timeout values, if
> - * not reset them both to 0 (=not used or unknown)
> + * Check that we have valid min and max pretimeout and timeout values,
> + * if not reset them both to 0 (=not used or unknown)
> */
> + if (wdd->min_pretimeout > wdd->max_pretimeout) {
> + pr_info("Invalid min and max pretimeout, resetting to 0\n");
> + wdd->min_pretimeout = 0;
> + wdd->max_pretimeout = 0;
> + }
> if (wdd->min_timeout > wdd->max_timeout) {
> pr_info("Invalid min and max timeout values, resetting to 0!\n");
> wdd->min_timeout = 0;
> wdd->max_timeout = 0;
> }
> + /*
> + * Check that we have valid min and max timeout values,
> + * if not reset them both to pretimeout limits
> + */
> + if (wdd->min_pretimeout && wdd->min_timeout < wdd->min_pretimeout) {
> + pr_info("Invalid min timeout, resetting to min pretimeout\n");
> + wdd->min_timeout = wdd->min_pretimeout;
> + }
> + if (wdd->max_pretimeout && wdd->max_timeout < wdd->max_pretimeout) {
> + pr_info("Invalid max timeout, resetting to max pretimeout\n");
> + wdd->max_timeout = wdd->max_pretimeout;
I think you should rather update max_pretimeout in this case, to
be < max_timeout.
> + }
> }
>
> /**
> - * watchdog_init_timeout() - initialize the timeout field
> + * watchdog_init_timeouts() - initialize the pretimeout and timeout field
> + * @pretimeout_parm: pretimeout module parameter
> * @timeout_parm: timeout module parameter
> * @dev: Device that stores the timeout-sec property
> *
> - * Initialize the timeout field of the watchdog_device struct with either the
> - * timeout module parameter (if it is valid value) or the timeout-sec property
> - * (only if it is a valid value and the timeout_parm is out of bounds).
> - * If none of them are valid then we keep the old value (which should normally
> - * be the default timeout value.
> + * Initialize the pretimeout and timeout field of the watchdog_device struct
> + * with either the pretimeout and timeout module parameter (if it is valid
> + * value) or the timeout-sec property (only if it is a valid value and the
> + * pretimeout_parm and timeout_parm is out of bounds). If none of them are
> + * valid, then we keep the old value (which should normally be the default
> + * timeout value).
> *
> * A zero is returned on success and -EINVAL for failure.
> */
> -int watchdog_init_timeout(struct watchdog_device *wdd,
> - unsigned int timeout_parm, struct device *dev)
> +int watchdog_init_timeouts(struct watchdog_device *wdd,
> + unsigned int pretimeout_parm,
> + unsigned int timeout_parm,
> + struct device *dev)
> {
> - unsigned int t = 0;
> - int ret = 0;
> + u32 timeouts[2];
> + int ret = 0, length = 0;
Please keep the longest variable chain first.
>
> - watchdog_check_min_max_timeout(wdd);
> + watchdog_check_min_max_timeouts(wdd);
>
> - /* try to get the timeout module parameter first */
> - if (!watchdog_timeout_invalid(wdd, timeout_parm) && timeout_parm) {
> - wdd->timeout = timeout_parm;
> - return ret;
> + /* try to get the timeout and pretimeout module parameter first */
> + if (pretimeout_parm) {
> + if (!watchdog_pretimeout_invalid(wdd, pretimeout_parm))
> + wdd->pretimeout = pretimeout_parm;
> + else
> + ret = -EINVAL;
> }
> - if (timeout_parm)
> +
> + if (timeout_parm) {
> + if (!watchdog_timeout_invalid(wdd, timeout_parm)) {
> + wdd->timeout = timeout_parm;
> + return ret;
This would return -EINVAL if timeout is correct but pretimeout isn't.
How about this ?
if (!ret)
return 0;
> + }
> ret = -EINVAL;
> + }
>
> /* try to get the timeout_sec property */
> if (dev == NULL || dev->of_node == NULL)
> return ret;
> - of_property_read_u32(dev->of_node, "timeout-sec", &t);
> - if (!watchdog_timeout_invalid(wdd, t) && t)
> - wdd->timeout = t;
> - else
> +
> + of_find_property(dev->of_node, "timeout-sec", &length);
> + if (length > 0 && length <= sizeof(u32) * 2) {
> + of_property_read_u32_array(dev->of_node,
> + "timeout-sec", timeouts,
> + length / sizeof(u32));
> + if (length == 2) {
> + if (!watchdog_pretimeout_invalid(wdd, timeouts[1]) &&
> + timeouts[1])
> + wdd->pretimeout = timeouts[1];
A pretimeout of 0 is a valid timeout, so why not use it ?
> + else
> + ret = -EINVAL;
and why is pretimeout == 0 considered invalid here ?
> + }
> +
> + if (!watchdog_timeout_invalid(wdd, timeouts[0]) && timeouts[0])
> + wdd->timeout = timeouts[0];
> + else
> + ret = -EINVAL;
> + } else {
> ret = -EINVAL;
> + }
>
> return ret;
> }
> -EXPORT_SYMBOL_GPL(watchdog_init_timeout);
> +EXPORT_SYMBOL_GPL(watchdog_init_timeouts);
>
> /**
> * watchdog_register_device() - register a watchdog device
> @@ -119,7 +164,7 @@ int watchdog_register_device(struct watchdog_device *wdd)
> if (wdd->ops->start == NULL || wdd->ops->stop == NULL)
> return -EINVAL;
>
> - watchdog_check_min_max_timeout(wdd);
> + watchdog_check_min_max_timeouts(wdd);
>
> /*
> * Note: now that all watchdog_device data has been verified, we
> diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
> index 6aaefba..a65a9b0 100644
> --- a/drivers/watchdog/watchdog_dev.c
> +++ b/drivers/watchdog/watchdog_dev.c
> @@ -218,6 +218,38 @@ out_timeout:
> }
>
> /*
> + * watchdog_set_pretimeout: set the watchdog timer pretimeout
> + * @wddev: the watchdog device to set the timeout for
> + * @pretimeout: pretimeout to set in seconds
> + */
> +
> +static int watchdog_set_pretimeout(struct watchdog_device *wddev,
> + unsigned int pretimeout)
> +{
> + int err;
> +
> + if (!wddev->ops->set_pretimeout ||
> + !(wddev->info->options & WDIOF_PRETIMEOUT))
> + return -EOPNOTSUPP;
> +
> + if (watchdog_pretimeout_invalid(wddev, pretimeout))
> + return -EINVAL;
> +
> + mutex_lock(&wddev->lock);
> +
> + if (test_bit(WDOG_UNREGISTERED, &wddev->status)) {
> + err = -ENODEV;
> + goto out_pretimeout;
> + }
> +
> + err = wddev->ops->set_pretimeout(wddev, pretimeout);
> +
> +out_pretimeout:
> + mutex_unlock(&wddev->lock);
> + return err;
> +}
> +
> +/*
> * watchdog_get_timeleft: wrapper to get the time left before a reboot
> * @wddev: the watchdog device to get the remaining time from
> * @timeleft: the time that's left
> @@ -388,6 +420,24 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
> if (wdd->timeout == 0)
> return -EOPNOTSUPP;
> return put_user(wdd->timeout, p);
> + case WDIOC_SETPRETIMEOUT:
> + if (get_user(val, p))
> + return -EFAULT;
> + err = watchdog_set_pretimeout(wdd, val);
> + if (err < 0)
> + return err;
> + /*
> + * If the watchdog is active then we send a keepalive ping
> + * to make sure that the watchdog keep's running (and if
s/keep's/keeps/
> + * possible that it takes the new timeout)
new pretimeout
> + */
> + watchdog_ping(wdd);
> + /* Fall */
> + case WDIOC_GETPRETIMEOUT:
> + /* pretimeout == 0 means that we don't know the pretimeout */
> + if (wdd->pretimeout == 0)
> + return -EOPNOTSUPP;
pretimeout == 0 is a valid parameter, though, and means that it is disabled.
So we can not return -EOPNOTSUPP here.
Either this code needs to explicitly check for pretimeout support,
or just return 0 if it is disabled / not supported.
> + return put_user(wdd->pretimeout, p);
> case WDIOC_GETTIMELEFT:
> err = watchdog_get_timeleft(wdd, &val);
> if (err)
> diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
> index a746bf5..e776e1d 100644
> --- a/include/linux/watchdog.h
> +++ b/include/linux/watchdog.h
> @@ -25,6 +25,7 @@ struct watchdog_device;
> * @ping: The routine that sends a keepalive ping to the watchdog device.
> * @status: The routine that shows the status of the watchdog device.
> * @set_timeout:The routine for setting the watchdog devices timeout value.
> + * @set_pretimeout:The routine for setting the watchdog devices pretimeout value
> * @get_timeleft:The routine that get's the time that's left before a reset.
> * @ref: The ref operation for dyn. allocated watchdog_device structs
> * @unref: The unref operation for dyn. allocated watchdog_device structs
> @@ -44,6 +45,7 @@ struct watchdog_ops {
> int (*ping)(struct watchdog_device *);
> unsigned int (*status)(struct watchdog_device *);
> int (*set_timeout)(struct watchdog_device *, unsigned int);
> + int (*set_pretimeout)(struct watchdog_device *, unsigned int);
> unsigned int (*get_timeleft)(struct watchdog_device *);
> void (*ref)(struct watchdog_device *);
> void (*unref)(struct watchdog_device *);
> @@ -62,6 +64,9 @@ struct watchdog_ops {
> * @timeout: The watchdog devices timeout value.
> * @min_timeout:The watchdog devices minimum timeout value.
> * @max_timeout:The watchdog devices maximum timeout value.
> + * @pretimeout: The watchdog devices pretimeout value.
> + * @min_pretimeout:The watchdog devices minimum pretimeout value.
> + * @max_pretimeout:The watchdog devices maximum pretimeout value.
> * @driver-data:Pointer to the drivers private data.
> * @lock: Lock for watchdog core internal use only.
> * @status: Field that contains the devices internal status bits.
> @@ -86,6 +91,9 @@ struct watchdog_device {
> unsigned int timeout;
> unsigned int min_timeout;
> unsigned int max_timeout;
> + unsigned int pretimeout;
> + unsigned int min_pretimeout;
> + unsigned int max_pretimeout;
> void *driver_data;
> struct mutex lock;
> unsigned long status;
> @@ -117,7 +125,17 @@ static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool noway
> static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t)
> {
> return ((wdd->max_timeout != 0) &&
> - (t < wdd->min_timeout || t > wdd->max_timeout));
> + (t < wdd->min_timeout || t > wdd->max_timeout ||
> + t < wdd->pretimeout));
< or <= ?
timeout == pretimeout implies that the pretimeout would expire immediately,
which doesn't seem to make much sense.
> +}
> +
> +/* Use the following function to check if a pretimeout value is invalid */
> +static inline bool watchdog_pretimeout_invalid(struct watchdog_device *wdd,
> + unsigned int t)
> +{
> + return (wdd->max_pretimeout != 0 &&
> + (t < wdd->min_pretimeout || t > wdd->max_pretimeout ||
> + (wdd->timeout != 0 && t > wdd->timeout)));
> or >= ?
> }
>
> /* Use the following functions to manipulate watchdog driver specific data */
> @@ -132,11 +150,20 @@ static inline void *watchdog_get_drvdata(struct watchdog_device *wdd)
> }
>
> /* drivers/watchdog/watchdog_core.c */
> -extern int watchdog_init_timeout(struct watchdog_device *wdd,
> - unsigned int timeout_parm, struct device *dev);
> +extern int watchdog_init_timeouts(struct watchdog_device *wdd,
> + unsigned int pretimeout_parm,
> + unsigned int timeout_parm,
> + struct device *dev);
> extern int watchdog_register_device(struct watchdog_device *);
> extern void watchdog_unregister_device(struct watchdog_device *);
>
> +static inline int watchdog_init_timeout(struct watchdog_device *wdd,
> + unsigned int timeout_parm,
> + struct device *dev)
> +{
> + return watchdog_init_timeouts(wdd, 0, timeout_parm, dev);
> +}
> +
> #ifdef CONFIG_HARDLOCKUP_DETECTOR
> void watchdog_nmi_disable_all(void);
> void watchdog_nmi_enable_all(void);
>
On 05/25/2015 03:03 AM, [email protected] wrote:
> From: Fu Wei <[email protected]>
>
> This driver bases on linux kernel watchdog framework, and
> use "pretimeout" in the framework. It supports getting timeout and
> pretimeout from parameter and FDT at the driver init stage.
> In first timeout, the interrupt routine run panic to save
> system context.
>
> Acked-by: Arnd Bergmann <[email protected]>
> Tested-by: Suravee Suthikulpanit <[email protected]>
> Signed-off-by: Fu Wei <[email protected]>
> ---
Comments inline.
Thanks,
Guenter
> drivers/watchdog/Kconfig | 11 +
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/sbsa_gwdt.c | 474 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 486 insertions(+)
> create mode 100644 drivers/watchdog/sbsa_gwdt.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index e5e7c55..554f18a 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -152,6 +152,17 @@ config ARM_SP805_WATCHDOG
> ARM Primecell SP805 Watchdog timer. This will reboot your system when
> the timeout is reached.
>
> +config ARM_SBSA_WATCHDOG
> + tristate "ARM SBSA Generic Watchdog"
> + depends on ARM64
> + depends on ARM_ARCH_TIMER
> + select WATCHDOG_CORE
> + help
> + ARM SBSA Generic Watchdog. This watchdog has two Watchdog timeouts.
> + The first timeout will trigger a panic; the second timeout will
> + trigger a system reset.
> + More details: ARM DEN0029B - Server Base System Architecture (SBSA)
> +
> config AT91RM9200_WATCHDOG
> tristate "AT91RM9200 watchdog"
> depends on SOC_AT91RM9200 && MFD_SYSCON
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 5c19294..471f1b7c 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -30,6 +30,7 @@ obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb.o
>
> # ARM Architecture
> obj-$(CONFIG_ARM_SP805_WATCHDOG) += sp805_wdt.o
> +obj-$(CONFIG_ARM_SBSA_WATCHDOG) += sbsa_gwdt.o
> obj-$(CONFIG_AT91RM9200_WATCHDOG) += at91rm9200_wdt.o
> obj-$(CONFIG_AT91SAM9X_WATCHDOG) += at91sam9_wdt.o
> obj-$(CONFIG_CADENCE_WATCHDOG) += cadence_wdt.o
> diff --git a/drivers/watchdog/sbsa_gwdt.c b/drivers/watchdog/sbsa_gwdt.c
> new file mode 100644
> index 0000000..0d1aff1
> --- /dev/null
> +++ b/drivers/watchdog/sbsa_gwdt.c
> @@ -0,0 +1,474 @@
> +/*
> + * SBSA(Server Base System Architecture) Generic Watchdog driver
> + *
> + * Copyright (c) 2015, Linaro Ltd.
> + * Author: Fu Wei <[email protected]>
> + * Suravee Suthikulpanit <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that 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.
> + *
> + * Note: This SBSA Generic watchdog driver is compatible with
> + * the pretimeout concept of Linux kernel.
> + * The timeout and pretimeout are set by the different REGs.
> + * The first watch period is set by writing WCV directly,
> + * that can support more than 10s timeout at the maximum
> + * system counter frequency.
> + * The second watch period is set by WOR(32bit) which will be loaded
> + * automatically by hardware, when WS0 is triggered.
> + * This gives a maximum watch period of around 10s at the maximum
> + * system counter frequency.
> + * The System Counter shall run at maximum of 400MHz.
> + * More details: ARM DEN0029B - Server Base System Architecture (SBSA)
> + *
> + * Kernel/API: P---------| pretimeout
> + * |-------------------------------T timeout
> + * SBSA GWDT: P--WOR---WS1 pretimeout
> + * |-------WCV----------WS0~~~~~~~~T timeout
> + */
> +
> +#include <linux/io.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/uaccess.h>
> +#include <linux/watchdog.h>
> +#include <asm/arch_timer.h>
> +
> +/* SBSA Generic Watchdog register definitions */
> +/* refresh frame */
> +#define SBSA_GWDT_WRR 0x000
> +
> +/* control frame */
> +#define SBSA_GWDT_WCS 0x000
> +#define SBSA_GWDT_WOR 0x008
> +#define SBSA_GWDT_WCV_LO 0x010
> +#define SBSA_GWDT_WCV_HI 0x014
> +
> +/* refresh/control frame */
> +#define SBSA_GWDT_W_IIDR 0xfcc
> +#define SBSA_GWDT_IDR 0xfd0
> +
> +/* Watchdog Control and Status Register */
> +#define SBSA_GWDT_WCS_EN BIT(0)
> +#define SBSA_GWDT_WCS_WS0 BIT(1)
> +#define SBSA_GWDT_WCS_WS1 BIT(2)
> +
> +/**
> + * struct sbsa_gwdt - Internal representation of the SBSA GWDT
> + * @wdd: kernel watchdog_device structure
> + * @clk: store the System Counter clock frequency, in Hz.
> + * @refresh_base: Virtual address of the watchdog refresh frame
> + * @control_base: Virtual address of the watchdog control frame
> + */
> +struct sbsa_gwdt {
> + struct watchdog_device wdd;
> + u32 clk;
> + void __iomem *refresh_base;
> + void __iomem *control_base;
> +};
> +
> +#define to_sbsa_gwdt(e) container_of(e, struct sbsa_gwdt, wdd)
> +
> +#define DEFAULT_TIMEOUT 10 /* seconds, the 1st + 2nd watch periods*/
That is a bit low for a default. Is that on purpose ?
Most drivers use 30 or 60 seconds.
> +#define DEFAULT_PRETIMEOUT 5 /* seconds, the 2nd watch period*/
> +
> +static unsigned int timeout_param;
> +module_param(timeout_param, uint, 0);
> +MODULE_PARM_DESC(timeout_param,
> + "Watchdog timeout in seconds. (>=0, default="
> + __MODULE_STRING(DEFAULT_TIMEOUT) ")");
> +
Why _param in the module parameter names ? Seems to be redundant.
> +static unsigned int max_timeout_param = UINT_MAX;
> +module_param(max_timeout_param, uint, 0);
> +MODULE_PARM_DESC(max_timeout_param,
> + "Watchdog max timeout in seconds. (>=0, default="
> + __MODULE_STRING(UINT_MAX) ")");
> +
Why do we want or need this parameter and max_pretimeout ? Those
are determined by the hardware.
> +static unsigned int pretimeout_param;
> +module_param(pretimeout_param, uint, 0);
> +MODULE_PARM_DESC(pretimeout_param,
> + "Watchdog pretimeout in seconds. (>=0, default="
> + __MODULE_STRING(DEFAULT_PRETIMEOUT) ")");
> +
> +static unsigned int max_pretimeout_param = U32_MAX;
> +module_param(max_pretimeout_param, uint, 0);
> +MODULE_PARM_DESC(max_pretimeout_param,
> + "Watchdog max pretimeout in seconds. (>=0, default="
> + __MODULE_STRING(U32_MAX) ")");
> +
> +static bool nowayout = WATCHDOG_NOWAYOUT;
> +module_param(nowayout, bool, S_IRUGO);
> +MODULE_PARM_DESC(nowayout,
> + "Watchdog cannot be stopped once started (default="
> + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
> +/*
> + * help functions for accessing 32bit registers of SBSA Generic Watchdog
> + */
> +static void sbsa_gwdt_cf_write(unsigned int reg, u32 val,
> + struct watchdog_device *wdd)
> +{
> + struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
> +
> + writel_relaxed(val, gwdt->control_base + reg);
> +}
> +
> +static void sbsa_gwdt_rf_write(unsigned int reg, u32 val,
> + struct watchdog_device *wdd)
> +{
> + struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
> +
> + writel_relaxed(val, gwdt->refresh_base + reg);
> +}
> +
> +static u32 sbsa_gwdt_cf_read(unsigned int reg, struct watchdog_device *wdd)
> +{
> + struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
> +
> + return readl_relaxed(gwdt->control_base + reg);
> +}
> +
> +/*
> + * help functions for accessing 64bit WCV register
> + */
> +static u64 sbsa_gwdt_get_wcv(struct watchdog_device *wdd)
> +{
> + u32 wcv_lo, wcv_hi;
> +
> + do {
> + wcv_hi = sbsa_gwdt_cf_read(SBSA_GWDT_WCV_HI, wdd);
> + wcv_lo = sbsa_gwdt_cf_read(SBSA_GWDT_WCV_LO, wdd);
> + } while (wcv_hi != sbsa_gwdt_cf_read(SBSA_GWDT_WCV_HI, wdd));
> +
> + return (((u64)wcv_hi << 32) | wcv_lo);
> +}
> +
> +static void sbsa_gwdt_set_wcv(struct watchdog_device *wdd, u64 value)
> +{
> + u32 wcv_lo, wcv_hi;
> +
> + wcv_lo = value & U32_MAX;
> + wcv_hi = (value >> 32) & U32_MAX;
> +
> + sbsa_gwdt_cf_write(SBSA_GWDT_WCV_HI, wcv_hi, wdd);
> + sbsa_gwdt_cf_write(SBSA_GWDT_WCV_LO, wcv_lo, wdd);
> +}
> +
> +static void reload_timeout_to_wcv(struct watchdog_device *wdd)
> +{
> + struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
> + u64 wcv;
> +
> + wcv = arch_counter_get_cntvct() +
> + (u64)(wdd->timeout - wdd->pretimeout) * gwdt->clk;
> +
> + sbsa_gwdt_set_wcv(wdd, wcv);
> +}
> +
> +/*
> + * Use the following function to update the timeout limits
> + * after updating pretimeout
> + */
> +static void sbsa_gwdt_update_limits(struct watchdog_device *wdd)
> +{
> + struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
> + u64 first_period_max = U64_MAX;
> +
> + do_div(first_period_max, gwdt->clk);
> +
> + wdd->min_timeout = wdd->pretimeout + 1;
> + wdd->max_timeout = min((uint)(wdd->pretimeout + first_period_max),
> + wdd->max_timeout);
> +}
> +
After understanding the watchdog a bit better now, I think you should drop
those updates and set
min_timeout = 1
max_timeout = min(UINT_MAX, U64_MAX / clk)
min_pretimeout = 0
max_pretimeout = U32_MAX / clk
and then ensure that pretimeout < timeout at runtime (if possible in
the infrastructure code).
Even at maximum clock rate, max_timeout is so large that anything else
is really overkill.
> +static int sbsa_gwdt_set_timeout(struct watchdog_device *wdd,
> + unsigned int timeout)
> +{
> + wdd->timeout = timeout;
> +
> + return 0;
> +}
> +
> +static int sbsa_gwdt_set_pretimeout(struct watchdog_device *wdd,
> + unsigned int pretimeout)
> +{
> + struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
> + u32 wor;
> +
> + wdd->pretimeout = pretimeout;
> + sbsa_gwdt_update_limits(wdd);
> +
> + if (!pretimeout)
> + /* gives sbsa_gwdt_start a chance to setup timeout */
> + wor = gwdt->clk;
> + else
> + wor = pretimeout * gwdt->clk;
> +
So in practice you always have a pretimeout of at least one second,
correct ? That kind of violates the ABI, which says that the pretimeout
should be disabled if set to 0. Is there anything we can do about that ?
What exactly happens if WOR = 0 ? Doesn't that just mean that the second
timeout will happen immediately, and isn't that what we would want if
pretimeout = 0 ?
> + /* refresh the WOR, that will cause an explicit watchdog refresh */
Except that we use wcv which needs a manual refresh, so this is a bit
misleading, isn't it ?
> + sbsa_gwdt_cf_write(SBSA_GWDT_WOR, wor, wdd);
> +
> + return 0;
> +}
> +
> +static unsigned int sbsa_gwdt_get_timeleft(struct watchdog_device *wdd)
> +{
> + struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
> + u64 timeleft = sbsa_gwdt_get_wcv(wdd) - arch_counter_get_cntvct();
> +
> + do_div(timeleft, gwdt->clk);
> +
> + return timeleft;
> +}
> +
> +static int sbsa_gwdt_start(struct watchdog_device *wdd)
> +{
> + /* Force refresh */
> + sbsa_gwdt_rf_write(SBSA_GWDT_WRR, 0xc0ffee, wdd);
> + /* writing WCS will cause an explicit watchdog refresh */
> + sbsa_gwdt_cf_write(SBSA_GWDT_WCS, SBSA_GWDT_WCS_EN, wdd);
> +
> + reload_timeout_to_wcv(wdd);
> +
> + return 0;
> +}
> +
> +static int sbsa_gwdt_stop(struct watchdog_device *wdd)
> +{
> + /* Force refresh */
> + sbsa_gwdt_rf_write(SBSA_GWDT_WRR, 0xc0ffee, wdd);
> + /* writing WCS will cause an explicit watchdog refresh */
> + sbsa_gwdt_cf_write(SBSA_GWDT_WCS, 0, wdd);
> +
> + return 0;
> +}
> +
> +static int sbsa_gwdt_keepalive(struct watchdog_device *wdd)
> +{
> + /*
> + * Writing WRR for an explicit watchdog refresh
> + * You can write anyting(like 0xc0ffee)
> + */
> + sbsa_gwdt_rf_write(SBSA_GWDT_WRR, 0xc0ffee, wdd);
Should that happen after writing wcv ?
> +
> + reload_timeout_to_wcv(wdd);
> +
> + return 0;
> +}
> +
> +static irqreturn_t sbsa_gwdt_interrupt(int irq, void *dev_id)
> +{
> + struct sbsa_gwdt *gwdt = (struct sbsa_gwdt *)dev_id;
> + struct watchdog_device *wdd = &gwdt->wdd;
> + u32 status;
> +
> + status = sbsa_gwdt_cf_read(SBSA_GWDT_WCS, wdd);
> +
> + if (status & SBSA_GWDT_WCS_WS0)
> + panic("SBSA Watchdog pre-timeout");
> +
> + return IRQ_HANDLED;
> +}
> +
> +static struct watchdog_info sbsa_gwdt_info = {
> + .identity = "SBSA Generic Watchdog",
> + .options = WDIOF_SETTIMEOUT |
> + WDIOF_KEEPALIVEPING |
> + WDIOF_MAGICCLOSE |
> + WDIOF_PRETIMEOUT |
> + WDIOF_CARDRESET,
> +};
> +
> +static struct watchdog_ops sbsa_gwdt_ops = {
> + .owner = THIS_MODULE,
> + .start = sbsa_gwdt_start,
> + .stop = sbsa_gwdt_stop,
> + .ping = sbsa_gwdt_keepalive,
> + .set_timeout = sbsa_gwdt_set_timeout,
> + .set_pretimeout = sbsa_gwdt_set_pretimeout,
> + .get_timeleft = sbsa_gwdt_get_timeleft,
> +};
> +
> +static int sbsa_gwdt_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct sbsa_gwdt *gwdt;
> + struct watchdog_device *wdd;
> + struct resource *res;
> + void *rf_base, *cf_base;
> + int irq;
> + u32 clk, status;
> + int ret = 0;
> + u64 first_period_max = U64_MAX;
> +
> + /*
> + * Get the frequency of system counter from
> + * the cp15 interface of ARM Generic timer
> + */
> + clk = arch_timer_get_cntfrq();
That can not return 0, presumably, from looking into its implementation.
And the system should panic if it is ever 0.
> + if (!clk) {
Given that, I don't think this check is necessary.
> + dev_err(dev, "System Counter frequency not available\n");
> + return -EINVAL;
> + }
> +
> + gwdt = devm_kzalloc(dev, sizeof(*gwdt), GFP_KERNEL);
> + if (!gwdt)
> + return -ENOMEM;
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "refresh");
> + rf_base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(rf_base))
> + return PTR_ERR(rf_base);
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "control");
> + cf_base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(cf_base))
> + return PTR_ERR(cf_base);
> +
> + irq = platform_get_irq_byname(pdev, "ws0");
> + if (irq < 0) {
> + dev_err(dev, "unable to get ws0 interrupt.\n");
> + return irq;
> + }
> +
> + gwdt->refresh_base = rf_base;
> + gwdt->control_base = cf_base;
> + gwdt->clk = clk;
> +
> + platform_set_drvdata(pdev, gwdt);
> +
> + wdd = &gwdt->wdd;
> + wdd->parent = dev;
> + wdd->info = &sbsa_gwdt_info;
> + wdd->ops = &sbsa_gwdt_ops;
> + watchdog_set_drvdata(wdd, gwdt);
> + watchdog_set_nowayout(wdd, nowayout);
> +
> + status = sbsa_gwdt_cf_read(SBSA_GWDT_WCS, wdd);
> + if (status & SBSA_GWDT_WCS_WS1) {
> + dev_warn(dev, "System reset by WDT(WCS: %x, WCV: %llx)\n",
> + status, sbsa_gwdt_get_wcv(wdd));
Does this message (specifically the WCS / WCV values) have any
useful meaning for the user ?
> + wdd->bootstatus |= WDIOF_CARDRESET;
> + }
> + /* Check if watchdog is already enabled */
> + if (status & SBSA_GWDT_WCS_EN) {
> + dev_warn(dev, "already enabled! WCS:0x%x\n", status);
> + sbsa_gwdt_keepalive(wdd);
You have not configured wdd->timeout and wdd->pretimeout here,
yet the function calls reload_timeout_to_wcv which needs it.
> + }
> +
> + wdd->min_pretimeout = 0;
> + wdd->max_pretimeout = min(U32_MAX / clk, max_pretimeout_param);
> + wdd->min_timeout = 1;
> + do_div(first_period_max, clk);
> + wdd->max_timeout = min((uint)(wdd->pretimeout + first_period_max),
> + max_timeout_param);
> +
> + wdd->pretimeout = DEFAULT_PRETIMEOUT;
> + wdd->timeout = DEFAULT_TIMEOUT;
> + watchdog_init_timeouts(wdd, pretimeout_param, timeout_param, dev);
> + /* update pretimeout to WOR */
> + sbsa_gwdt_cf_write(SBSA_GWDT_WOR, wdd->pretimeout * clk, wdd);
This is interesting because you set WOR to 0 here if pretimeout is 0.
Yet, when pretimeout is updated later on, you always set it to at least
one second. Any reason for doing this differently ?
If the above works, and presumably you have tested it, I don't see why
it would be necessary to set WOR to a value larger than 0 when updating
pretimeout.
> +
> + ret = devm_request_irq(dev, irq, sbsa_gwdt_interrupt, IRQF_TIMER,
> + pdev->name, gwdt);
> + if (ret) {
> + dev_err(dev, "unable to request IRQ %d\n", irq);
> + return ret;
> + }
> +
> + ret = watchdog_register_device(wdd);
> + if (ret)
> + return ret;
> +
> + dev_info(dev, "Initialized with %ds timeout, %ds pretimeout @ %uHz\n",
> + wdd->timeout, wdd->pretimeout, gwdt->clk);
400000Hz reads a bit odd. How about a space between the number and Hz ?
> +
> + return 0;
> +}
> +
> +static void sbsa_gwdt_shutdown(struct platform_device *pdev)
> +{
> + struct sbsa_gwdt *gwdt = platform_get_drvdata(pdev);
> +
> + sbsa_gwdt_stop(&gwdt->wdd);
> +}
> +
> +static int sbsa_gwdt_remove(struct platform_device *pdev)
> +{
> + struct sbsa_gwdt *gwdt = platform_get_drvdata(pdev);
> + int ret = 0;
> +
> + if (!nowayout)
> + ret = sbsa_gwdt_stop(&gwdt->wdd);
> +
I don't think you should do anything here. The driver can only be removed
if closed, and it that case the watchdog will already have been stopped,
or if nowayout was set it won't be stopped. Either case it is already in
the state we want it to be in.
> + watchdog_unregister_device(&gwdt->wdd);
> +
> + return ret;
> +}
> +
> +/* Disable watchdog if it is active during suspend */
> +static int __maybe_unused sbsa_gwdt_suspend(struct device *dev)
> +{
> + struct sbsa_gwdt *gwdt = dev_get_drvdata(dev);
> +
> + if (watchdog_active(&gwdt->wdd))
> + sbsa_gwdt_stop(&gwdt->wdd);
> +
> + return 0;
> +}
> +
> +/* Enable watchdog and configure it if necessary */
> +static int __maybe_unused sbsa_gwdt_resume(struct device *dev)
> +{
> + struct sbsa_gwdt *gwdt = dev_get_drvdata(dev);
> +
> + if (watchdog_active(&gwdt->wdd))
> + sbsa_gwdt_start(&gwdt->wdd);
> +
> + return 0;
> +}
> +
> +static const struct dev_pm_ops sbsa_gwdt_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(sbsa_gwdt_suspend, sbsa_gwdt_resume)
> +};
> +
> +static const struct of_device_id sbsa_gwdt_of_match[] = {
> + { .compatible = "arm,sbsa-gwdt", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, sbsa_gwdt_of_match);
> +
> +static const struct platform_device_id sbsa_gwdt_pdev_match[] = {
> + { .name = "sbsa-gwdt", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(platform, sbsa_gwdt_pdev_match);
> +
> +static struct platform_driver sbsa_gwdt_driver = {
> + .driver = {
> + .name = "sbsa-gwdt",
> + .pm = &sbsa_gwdt_pm_ops,
> + .of_match_table = sbsa_gwdt_of_match,
> + },
> + .probe = sbsa_gwdt_probe,
> + .remove = sbsa_gwdt_remove,
> + .shutdown = sbsa_gwdt_shutdown,
> + .id_table = sbsa_gwdt_pdev_match,
> +};
> +
> +module_platform_driver(sbsa_gwdt_driver);
> +
> +MODULE_DESCRIPTION("SBSA Generic Watchdog Driver");
> +MODULE_VERSION("v1.0");
> +MODULE_AUTHOR("Fu Wei <[email protected]>");
> +MODULE_AUTHOR("Suravee Suthikulpanit <[email protected]>");
> +MODULE_LICENSE("GPL v2");
>
Hi Fu Wei,
Some minor comments inline.
On 2015年05月25日 18:03, [email protected] wrote:
> From: Fu Wei <[email protected]>
>
> Parse SBSA Generic Watchdog Structure in GTDT table of ACPI,
> and create a platform device with that information.
> This platform device can be used by the ARM SBSA Generic
> Watchdog driver.
>
> Tested-by: Suravee Suthikulpanit <[email protected]>
> Tested-by: Timur Tabi <[email protected]>
> Signed-off-by: Fu Wei <[email protected]>
> ---
> arch/arm64/kernel/acpi.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 145 insertions(+)
>
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index 8b83955..c95deec 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -23,6 +23,7 @@
> #include <linux/irqdomain.h>
> #include <linux/memblock.h>
> #include <linux/of_fdt.h>
> +#include <linux/platform_device.h>
> #include <linux/smp.h>
>
> #include <asm/cputype.h>
> @@ -343,3 +344,147 @@ void __init acpi_gic_init(void)
>
> early_acpi_os_unmap_memory((char *)table, tbl_size);
> }
please add
#ifdef CONFIG_ARM_SBSA_WATCHDOG
(acpi gtdt code)
#endif
> +
> +static int __init acpi_gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd,
> + int index)
> +{
> + struct platform_device *pdev;
> + struct resource *res;
> + u32 gsi, flags;
> + int irq, trigger, polarity;
> + resource_size_t rf_base_phy, cf_base_phy;
> + int err = -ENOMEM;
> +
> + /*
> + * Get SBSA Generic Watchdog info
> + * from a Watchdog GT type structure in GTDT
> + */
> + rf_base_phy = (resource_size_t)wd->refresh_frame_address;
> + cf_base_phy = (resource_size_t)wd->control_frame_address;
> + gsi = wd->timer_interrupt;
> + flags = wd->timer_flags;
> +
> + pr_debug("GTDT: a Watchdog GT structure(0x%llx/0x%llx gsi:%u flags:0x%x)\n",
> + rf_base_phy, cf_base_phy, gsi, flags);
> +
> + if (!(rf_base_phy && cf_base_phy && gsi)) {
> + pr_err("GTDT: failed geting the device info.\n");
> + return -EINVAL;
> + }
> +
> + trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
> + : ACPI_LEVEL_SENSITIVE;
> + polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
> + : ACPI_ACTIVE_HIGH;
> + irq = acpi_register_gsi(NULL, gsi, trigger, polarity);
> + if (irq < 0) {
> + pr_err("GTDT: failed to register GSI of the Watchdog GT.\n");
> + return -EINVAL;
> + }
> +
> + /*
> + * Add a platform device named "sbsa-gwdt" to match the platform driver.
> + * "sbsa-gwdt": SBSA(Server Base System Architecture) Generic Watchdog
> + * The platform driver can get device info below by matching this name.
* The platform driver (drivers/watchdog/sbsa_gwdt.c) can get device info
below by matching this name.
Adding the file name which will help for review and maintain in my
opinion.
> + */
> + pdev = platform_device_alloc("sbsa-gwdt", index);
> + if (!pdev)
> + goto err_unregister_gsi;
> +
> + res = kcalloc(3, sizeof(*res), GFP_KERNEL);
> + if (!res)
> + goto err_device_put;
> +
> + /*
> + * According to SBSA specification the size of refresh and control
> + * frames of SBSA Generic Watchdog is SZ_4K(Offset 0x000 – 0xFFF).
> + */
> + res[0].start = rf_base_phy;
> + res[0].end = rf_base_phy + SZ_4K - 1;
> + res[0].name = "refresh";
> + res[0].flags = IORESOURCE_MEM;
> +
> + res[1].start = cf_base_phy;
> + res[1].end = cf_base_phy + SZ_4K - 1;
> + res[1].name = "control";
> + res[1].flags = IORESOURCE_MEM;
> +
> + res[2].start = irq;
> + res[2].end = res[2].start;
> + res[2].name = "ws0";
> + res[2].flags = IORESOURCE_IRQ;
> +
> + err = platform_device_add_resources(pdev, res, 3);
> + if (err)
> + goto err_free_res;
> +
> + err = platform_device_add(pdev);
...
> + if (err)
> + goto err_free_res;
> +
> + return 0;
How about
if (!err)
return 0;
then no need for goto err_free_res and save two lines of codes.
Other than that,
Acked-by: Hanjun Guo <[email protected]>
Thanks
Hanjun
On Mon, May 25, 2015 at 11:03:13AM +0100, [email protected] wrote:
> From: Fu Wei <[email protected]>
>
> Parse SBSA Generic Watchdog Structure in GTDT table of ACPI,
> and create a platform device with that information.
> This platform device can be used by the ARM SBSA Generic
> Watchdog driver.
>
> Tested-by: Suravee Suthikulpanit <[email protected]>
> Tested-by: Timur Tabi <[email protected]>
> Signed-off-by: Fu Wei <[email protected]>
> ---
> arch/arm64/kernel/acpi.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 145 insertions(+)
Why does this all need to be under arch/arm64? The GTDT really isn't
architecture-specific, so I'd *much* rather it was parsed in the driver code
itself, like we already do for the architected timer. The GIC is an
exception because it's in the MADT, which we need to parse in the arch code
to configure SMP properly.
Will
Hi Will,
On 26 May 2015 at 08:28, Will Deacon <[email protected]> wrote:
> On Mon, May 25, 2015 at 11:03:13AM +0100, [email protected] wrote:
>> From: Fu Wei <[email protected]>
>>
>> Parse SBSA Generic Watchdog Structure in GTDT table of ACPI,
>> and create a platform device with that information.
>> This platform device can be used by the ARM SBSA Generic
>> Watchdog driver.
>>
>> Tested-by: Suravee Suthikulpanit <[email protected]>
>> Tested-by: Timur Tabi <[email protected]>
>> Signed-off-by: Fu Wei <[email protected]>
>> ---
>> arch/arm64/kernel/acpi.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 145 insertions(+)
>
> Why does this all need to be under arch/arm64? The GTDT really isn't
> architecture-specific, so I'd *much* rather it was parsed in the driver code
> itself, like we already do for the architected timer. The GIC is an
> exception because it's in the MADT, which we need to parse in the arch code
> to configure SMP properly.
I'm not really against refactoring the code. But the GTDT looks quite
specific to ARM..
---8<----
5.2.24 Generic Timer Description Table (GTDT)
This section describes the format of the Generic Timer Description
Table (GTDT), which provides
OSPM with information about a system’s Generic Timers configuration.
The Generic Timer (GT) is
a standard timer interface implemented on ARM processor-based systems.
The GT hardware
specification can be found at Links to ACPI-Related Documents
(http://uefi.org/acpi) under the
heading ARM Architecture. The GTDT provides OSPM with information
about a system's GT
interrupt configurations, for both per-processor timers, and platform
(memory-mapped) timers.
The GT specification defines the following per-processor timers:
• Secure privilege level 1 (EL1) timer,
• Non-Secure EL1 timer,
• Non-Secure privilege level 2 (EL2) timer,
• Virtual timer,
and the following Platform (memory-mapped) timers.
• GT Block
• Server Base System Architecture (SBSA) Generic Watchdog
---8<----
Thanks,
Ashwin.
On Tue, May 26, 2015 at 04:02:56PM +0100, Ashwin Chaugule wrote:
> On 26 May 2015 at 08:28, Will Deacon <[email protected]> wrote:
> > On Mon, May 25, 2015 at 11:03:13AM +0100, [email protected] wrote:
> >> From: Fu Wei <[email protected]>
> >>
> >> Parse SBSA Generic Watchdog Structure in GTDT table of ACPI,
> >> and create a platform device with that information.
> >> This platform device can be used by the ARM SBSA Generic
> >> Watchdog driver.
> >>
> >> Tested-by: Suravee Suthikulpanit <[email protected]>
> >> Tested-by: Timur Tabi <[email protected]>
> >> Signed-off-by: Fu Wei <[email protected]>
> >> ---
> >> arch/arm64/kernel/acpi.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++
> >> 1 file changed, 145 insertions(+)
> >
> > Why does this all need to be under arch/arm64? The GTDT really isn't
> > architecture-specific, so I'd *much* rather it was parsed in the driver code
> > itself, like we already do for the architected timer. The GIC is an
> > exception because it's in the MADT, which we need to parse in the arch code
> > to configure SMP properly.
>
> I'm not really against refactoring the code. But the GTDT looks quite
> specific to ARM..
>
> ---8<----
> 5.2.24 Generic Timer Description Table (GTDT)
> This section describes the format of the Generic Timer Description
> Table (GTDT), which provides
> OSPM with information about a system’s Generic Timers configuration.
> The Generic Timer (GT) is
> a standard timer interface implemented on ARM processor-based systems.
> The GT hardware
> specification can be found at Links to ACPI-Related Documents
> (http://uefi.org/acpi) under the
> heading ARM Architecture. The GTDT provides OSPM with information
> about a system's GT
> interrupt configurations, for both per-processor timers, and platform
> (memory-mapped) timers.
> The GT specification defines the following per-processor timers:
> • Secure privilege level 1 (EL1) timer,
> • Non-Secure EL1 timer,
> • Non-Secure privilege level 2 (EL2) timer,
> • Virtual timer,
> and the following Platform (memory-mapped) timers.
> • GT Block
> • Server Base System Architecture (SBSA) Generic Watchdog
> ---8<----
Sure, the device it describes may only ever exist on ARM systems, but by
that logic then we should be moving lots of drivers back under arch/arm[64].
The ARM architecture says precisely *nothing* about ACPI, so we should
try to keep arch/arm64/kernel/acpi.c to a minimum and not shovel all sorts
of table conversion code in there for random peripherals.
Will
On 26 May 2015 at 11:18, Will Deacon <[email protected]> wrote:
> On Tue, May 26, 2015 at 04:02:56PM +0100, Ashwin Chaugule wrote:
>> On 26 May 2015 at 08:28, Will Deacon <[email protected]> wrote:
>> > On Mon, May 25, 2015 at 11:03:13AM +0100, [email protected] wrote:
>> >> From: Fu Wei <[email protected]>
>> >>
>> >> Parse SBSA Generic Watchdog Structure in GTDT table of ACPI,
>> >> and create a platform device with that information.
>> >> This platform device can be used by the ARM SBSA Generic
>> >> Watchdog driver.
>> >>
>> >> Tested-by: Suravee Suthikulpanit <[email protected]>
>> >> Tested-by: Timur Tabi <[email protected]>
>> >> Signed-off-by: Fu Wei <[email protected]>
>> >> ---
>> >> arch/arm64/kernel/acpi.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++
>> >> 1 file changed, 145 insertions(+)
>> >
>> > Why does this all need to be under arch/arm64? The GTDT really isn't
>> > architecture-specific, so I'd *much* rather it was parsed in the driver code
>> > itself, like we already do for the architected timer. The GIC is an
>> > exception because it's in the MADT, which we need to parse in the arch code
>> > to configure SMP properly.
>>
>> I'm not really against refactoring the code. But the GTDT looks quite
>> specific to ARM..
>>
>> ---8<----
>> 5.2.24 Generic Timer Description Table (GTDT)
>> This section describes the format of the Generic Timer Description
>> Table (GTDT), which provides
>> OSPM with information about a system’s Generic Timers configuration.
>> The Generic Timer (GT) is
>> a standard timer interface implemented on ARM processor-based systems.
>> The GT hardware
>> specification can be found at Links to ACPI-Related Documents
>> (http://uefi.org/acpi) under the
>> heading ARM Architecture. The GTDT provides OSPM with information
>> about a system's GT
>> interrupt configurations, for both per-processor timers, and platform
>> (memory-mapped) timers.
>> The GT specification defines the following per-processor timers:
>> • Secure privilege level 1 (EL1) timer,
>> • Non-Secure EL1 timer,
>> • Non-Secure privilege level 2 (EL2) timer,
>> • Virtual timer,
>> and the following Platform (memory-mapped) timers.
>> • GT Block
>> • Server Base System Architecture (SBSA) Generic Watchdog
>> ---8<----
>
> Sure, the device it describes may only ever exist on ARM systems, but by
> that logic then we should be moving lots of drivers back under arch/arm[64].
Sure. Not arguing about that. :) You said the GTDT isn't really arch
specific. That was a bit confusing.
>
> The ARM architecture says precisely *nothing* about ACPI, so we should
> try to keep arch/arm64/kernel/acpi.c to a minimum and not shovel all sorts
> of table conversion code in there for random peripherals.
>
> Will
On Tue, May 26, 2015 at 04:18:42PM +0100, Will Deacon wrote:
> On Tue, May 26, 2015 at 04:02:56PM +0100, Ashwin Chaugule wrote:
> > On 26 May 2015 at 08:28, Will Deacon <[email protected]> wrote:
> > > On Mon, May 25, 2015 at 11:03:13AM +0100, [email protected] wrote:
> > >> From: Fu Wei <[email protected]>
> > >>
> > >> Parse SBSA Generic Watchdog Structure in GTDT table of ACPI,
> > >> and create a platform device with that information.
> > >> This platform device can be used by the ARM SBSA Generic
> > >> Watchdog driver.
> > >>
> > >> Tested-by: Suravee Suthikulpanit <[email protected]>
> > >> Tested-by: Timur Tabi <[email protected]>
> > >> Signed-off-by: Fu Wei <[email protected]>
> > >> ---
> > >> arch/arm64/kernel/acpi.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++
> > >> 1 file changed, 145 insertions(+)
> > >
> > > Why does this all need to be under arch/arm64? The GTDT really isn't
> > > architecture-specific, so I'd *much* rather it was parsed in the driver code
> > > itself, like we already do for the architected timer. The GIC is an
> > > exception because it's in the MADT, which we need to parse in the arch code
> > > to configure SMP properly.
> >
> > I'm not really against refactoring the code. But the GTDT looks quite
> > specific to ARM..
> >
> > ---8<----
> > 5.2.24 Generic Timer Description Table (GTDT)
> > This section describes the format of the Generic Timer Description
> > Table (GTDT), which provides
> > OSPM with information about a system’s Generic Timers configuration.
> > The Generic Timer (GT) is
> > a standard timer interface implemented on ARM processor-based systems.
> > The GT hardware
> > specification can be found at Links to ACPI-Related Documents
> > (http://uefi.org/acpi) under the
> > heading ARM Architecture. The GTDT provides OSPM with information
> > about a system's GT
> > interrupt configurations, for both per-processor timers, and platform
> > (memory-mapped) timers.
> > The GT specification defines the following per-processor timers:
> > • Secure privilege level 1 (EL1) timer,
> > • Non-Secure EL1 timer,
> > • Non-Secure privilege level 2 (EL2) timer,
> > • Virtual timer,
> > and the following Platform (memory-mapped) timers.
> > • GT Block
> > • Server Base System Architecture (SBSA) Generic Watchdog
> > ---8<----
>
> Sure, the device it describes may only ever exist on ARM systems, but by
> that logic then we should be moving lots of drivers back under arch/arm[64].
>
It is nt the driver, but its instantiation. The question here would be
how and where to instantiate the driver, not where the driver itself
is located. The driver itself is ACPI agnostic.
What you are really saying is that you want the driver instantiation
to be moved into the driver.
Guenter
On 26 May 2015 at 23:36, Guenter Roeck <[email protected]> wrote:
> On Tue, May 26, 2015 at 04:18:42PM +0100, Will Deacon wrote:
>> On Tue, May 26, 2015 at 04:02:56PM +0100, Ashwin Chaugule wrote:
>> > On 26 May 2015 at 08:28, Will Deacon <[email protected]> wrote:
>> > > On Mon, May 25, 2015 at 11:03:13AM +0100, [email protected] wrote:
>> > >> From: Fu Wei <[email protected]>
>> > >>
>> > >> Parse SBSA Generic Watchdog Structure in GTDT table of ACPI,
>> > >> and create a platform device with that information.
>> > >> This platform device can be used by the ARM SBSA Generic
>> > >> Watchdog driver.
>> > >>
>> > >> Tested-by: Suravee Suthikulpanit <[email protected]>
>> > >> Tested-by: Timur Tabi <[email protected]>
>> > >> Signed-off-by: Fu Wei <[email protected]>
>> > >> ---
>> > >> arch/arm64/kernel/acpi.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++
>> > >> 1 file changed, 145 insertions(+)
>> > >
>> > > Why does this all need to be under arch/arm64? The GTDT really isn't
>> > > architecture-specific, so I'd *much* rather it was parsed in the driver code
>> > > itself, like we already do for the architected timer. The GIC is an
>> > > exception because it's in the MADT, which we need to parse in the arch code
>> > > to configure SMP properly.
>> >
>> > I'm not really against refactoring the code. But the GTDT looks quite
>> > specific to ARM..
>> >
>> > ---8<----
>> > 5.2.24 Generic Timer Description Table (GTDT)
>> > This section describes the format of the Generic Timer Description
>> > Table (GTDT), which provides
>> > OSPM with information about a system’s Generic Timers configuration.
>> > The Generic Timer (GT) is
>> > a standard timer interface implemented on ARM processor-based systems.
>> > The GT hardware
>> > specification can be found at Links to ACPI-Related Documents
>> > (http://uefi.org/acpi) under the
>> > heading ARM Architecture. The GTDT provides OSPM with information
>> > about a system's GT
>> > interrupt configurations, for both per-processor timers, and platform
>> > (memory-mapped) timers.
>> > The GT specification defines the following per-processor timers:
>> > • Secure privilege level 1 (EL1) timer,
>> > • Non-Secure EL1 timer,
>> > • Non-Secure privilege level 2 (EL2) timer,
>> > • Virtual timer,
>> > and the following Platform (memory-mapped) timers.
>> > • GT Block
>> > • Server Base System Architecture (SBSA) Generic Watchdog
>> > ---8<----
>>
>> Sure, the device it describes may only ever exist on ARM systems, but by
>> that logic then we should be moving lots of drivers back under arch/arm[64].
>>
> It is nt the driver, but its instantiation. The question here would be
> how and where to instantiate the driver, not where the driver itself
> is located. The driver itself is ACPI agnostic.
Hi Will,
I really don't mind to refactor the code, If we can make this patch better.
But for now, I can't see the good reason to move ACPI-relevant code
into a watchdog driver.
The reasons I put the code here are
(1)SBSA watchdog only for ARM64
(2)GTDT only for ARM, design for ARM,
(3)For ARM Architecture, only ARM64 support ACPI.
For minimizing arch/arm64/kernel/acpi.c, we can't put the code here,
and we had better keep these code outside the driver,
So do you have any suggestion for the better location of the GTDT code?
Great thanks for your help.
>
> What you are really saying is that you want the driver instantiation
> to be moved into the driver.
>
> Guenter
--
Best regards,
Fu Wei
Software Engineer
Red Hat Software (Beijing) Co.,Ltd.Shanghai Branch
Ph: +86 21 61221326(direct)
Ph: +86 186 2020 4684 (mobile)
Room 1512, Regus One Corporate Avenue,Level 15,
One Corporate Avenue,222 Hubin Road,Huangpu District,
Shanghai,China 200021
On 05/26/2015 03:28 AM, Hanjun Guo wrote:
>> early_acpi_os_unmap_memory((char *)table, tbl_size);
>> }
>
> please add
>
> #ifdef CONFIG_ARM_SBSA_WATCHDOG
> (acpi gtdt code)
> #endif
I don't agree with this. The GTDT should be parsed even if there's no
watchdog driver compiled for this kernel. There are no other #ifdefs in
this file.
>> + * Add a platform device named "sbsa-gwdt" to match the platform
>> driver.
>> + * "sbsa-gwdt": SBSA(Server Base System Architecture) Generic
>> Watchdog
>> + * The platform driver can get device info below by matching this
>> name.
>
> * The platform driver (drivers/watchdog/sbsa_gwdt.c) can get device info
> below by matching this name.
>
> Adding the file name which will help for review and maintain in my
> opinion.
Except it will cause problems if the driver is renamed or moved. I
don't think this is a good idea, either (sorry!)
--
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.
On 05/25/2015 05:03 AM, [email protected] wrote:
> +/*
> + * help functions for accessing 32bit registers of SBSA Generic Watchdog
> + */
> +static void sbsa_gwdt_cf_write(unsigned int reg, u32 val,
> + struct watchdog_device *wdd)
> +{
> + struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
> +
> + writel_relaxed(val, gwdt->control_base + reg);
> +}
> +
> +static void sbsa_gwdt_rf_write(unsigned int reg, u32 val,
> + struct watchdog_device *wdd)
> +{
> + struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
> +
> + writel_relaxed(val, gwdt->refresh_base + reg);
> +}
> +
> +static u32 sbsa_gwdt_cf_read(unsigned int reg, struct watchdog_device *wdd)
> +{
> + struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
> +
> + return readl_relaxed(gwdt->control_base + reg);
> +}
I don't understand the value of these functions. You're just adding
overhead to each read and write by dereferencing wdd every time. I
would get rid of them and just call readl_relaxed() and writel_relaxed()
directly.
> +/*
> + * help functions for accessing 64bit WCV register
> + */
> +static u64 sbsa_gwdt_get_wcv(struct watchdog_device *wdd)
> +{
> + u32 wcv_lo, wcv_hi;
> +
> + do {
> + wcv_hi = sbsa_gwdt_cf_read(SBSA_GWDT_WCV_HI, wdd);
> + wcv_lo = sbsa_gwdt_cf_read(SBSA_GWDT_WCV_LO, wdd);
> + } while (wcv_hi != sbsa_gwdt_cf_read(SBSA_GWDT_WCV_HI, wdd));
Please add a comment indicating that you're trying to read WCV atomically.
> +
> + return (((u64)wcv_hi << 32) | wcv_lo);
> +}
How about defining this macro:
#define make64(high, low) (((u64)(high) << 32) | (low))
and using it instead? That makes the code easier to read.
> +
> +static void sbsa_gwdt_set_wcv(struct watchdog_device *wdd, u64 value)
> +{
> + u32 wcv_lo, wcv_hi;
> +
> + wcv_lo = value & U32_MAX;
> + wcv_hi = (value >> 32) & U32_MAX;
Use upper_32_bits() and lower_32_bits() instead.
> +
> + sbsa_gwdt_cf_write(SBSA_GWDT_WCV_HI, wcv_hi, wdd);
> + sbsa_gwdt_cf_write(SBSA_GWDT_WCV_LO, wcv_lo, wdd);
> +}
> +
> +static void reload_timeout_to_wcv(struct watchdog_device *wdd)
This should be sbsa_gwdt_reload_timeout_to_wcv()
> +{
> + struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
> + u64 wcv;
> +
> + wcv = arch_counter_get_cntvct() +
> + (u64)(wdd->timeout - wdd->pretimeout) * gwdt->clk;
> +
> + sbsa_gwdt_set_wcv(wdd, wcv);
Shouldn't you program WCV and WOR together?
> +static int sbsa_gwdt_set_pretimeout(struct watchdog_device *wdd,
> + unsigned int pretimeout)
> +{
> + struct sbsa_gwdt *gwdt = to_sbsa_gwdt(wdd);
> + u32 wor;
> +
> + wdd->pretimeout = pretimeout;
> + sbsa_gwdt_update_limits(wdd);
> +
> + if (!pretimeout)
> + /* gives sbsa_gwdt_start a chance to setup timeout */
> + wor = gwdt->clk;
> + else
> + wor = pretimeout * gwdt->clk;
> +
> + /* refresh the WOR, that will cause an explicit watchdog refresh */
> + sbsa_gwdt_cf_write(SBSA_GWDT_WOR, wor, wdd);
Why not just ping the watchdog explicitely?
> +static irqreturn_t sbsa_gwdt_interrupt(int irq, void *dev_id)
> +{
> + struct sbsa_gwdt *gwdt = (struct sbsa_gwdt *)dev_id;
> + struct watchdog_device *wdd = &gwdt->wdd;
> + u32 status;
> +
> + status = sbsa_gwdt_cf_read(SBSA_GWDT_WCS, wdd);
> +
> + if (status & SBSA_GWDT_WCS_WS0)
This should always be true. Instead of reading WCS, I think you should
just panic().
> +static int sbsa_gwdt_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct sbsa_gwdt *gwdt;
> + struct watchdog_device *wdd;
> + struct resource *res;
> + void *rf_base, *cf_base;
> + int irq;
> + u32 clk, status;
> + int ret = 0;
> + u64 first_period_max = U64_MAX;
> +
> + /*
> + * Get the frequency of system counter from
> + * the cp15 interface of ARM Generic timer
> + */
> + clk = arch_timer_get_cntfrq();
> + if (!clk) {
You have
depends on ARM_ARCH_TIMER
in your Kconfig, so you don't need to check the return of
arch_timer_get_cntfrq(). It can never be zero.
Also, I would not use the variable name 'clk', because that's usually
used for a "struct clk" object. I would call this "freq" instead.
--
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.
On Tue, May 26, 2015 at 11:35:19AM -0500, Timur Tabi wrote:
> On 05/26/2015 03:28 AM, Hanjun Guo wrote:
>
> >> early_acpi_os_unmap_memory((char *)table, tbl_size);
> >> }
> >
> >please add
> >
> >#ifdef CONFIG_ARM_SBSA_WATCHDOG
> >(acpi gtdt code)
> >#endif
>
> I don't agree with this. The GTDT should be parsed even if there's no
> watchdog driver compiled for this kernel. There are no other #ifdefs in
> this file.
>
Me not either, but then I thought this is really a maintainer question.
If the maintainers want out-of-subsystem #ifdefs in the code, who am I
to complain.
Should be "#if IS_ENABLED(CONFIG_ARM_SBSA_WATCHDOG)", though, if we go
along that route.
Guenter
On 2015年05月27日 00:35, Timur Tabi wrote:
> On 05/26/2015 03:28 AM, Hanjun Guo wrote:
>
>>> early_acpi_os_unmap_memory((char *)table, tbl_size);
>>> }
>>
>> please add
>>
>> #ifdef CONFIG_ARM_SBSA_WATCHDOG
>> (acpi gtdt code)
>> #endif
>
> I don't agree with this. The GTDT should be parsed even if there's no
> watchdog driver compiled for this kernel. There are no other #ifdefs in
> this file.
So what's the point of parse GTDT and alloc memories for it if there
is no watchdog driver compiled for the kernel? will the module insmod
later even if the CONFIG_ARM_SBSA_WATCHDOG=n?
>
>>> + * Add a platform device named "sbsa-gwdt" to match the platform
>>> driver.
>>> + * "sbsa-gwdt": SBSA(Server Base System Architecture) Generic
>>> Watchdog
>>> + * The platform driver can get device info below by matching this
>>> name.
>>
>> * The platform driver (drivers/watchdog/sbsa_gwdt.c) can get device info
>> below by matching this name.
>>
>> Adding the file name which will help for review and maintain in my
>> opinion.
>
> Except it will cause problems if the driver is renamed or moved. I
> don't think this is a good idea, either (sorry!)
OK, that's good point. but what I proposed is some hint to which driver
will use the data prepared in this file, we can easily understand it
in this patchset, but if just review the code in this fiel, I think
people will be confused without detail comments.
Thanks
Hanjun
Hanjun Guo wrote:
>> I don't agree with this. The GTDT should be parsed even if there's no
>> watchdog driver compiled for this kernel. There are no other #ifdefs in
>> this file.
>
> So what's the point of parse GTDT and alloc memories for it if there
> is no watchdog driver compiled for the kernel?
I don't think it's normal policy to generate a platform only if one
specific driver is enabled.
> will the module insmod
> later even if the CONFIG_ARM_SBSA_WATCHDOG=n?
I think that actually can work, but it's not a good reason by itself.
> OK, that's good point. but what I proposed is some hint to which driver
> will use the data prepared in this file, we can easily understand it
> in this patchset, but if just review the code in this fiel, I think
> people will be confused without detail comments.
All anyone needs to is
git grep "sbsa-gwdt"
And you'll find the driver.
--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the
Code Aurora Forum, hosted by The Linux Foundation.
Hi Guenter , Timur
On 30 May 2015 at 06:10, Guenter Roeck <[email protected]> wrote:
> On 05/29/2015 08:46 AM, Timur Tabi wrote:
>>
>> On 05/29/2015 09:32 AM, Fu Wei wrote:
>>>
>>> It is a SPI, every CPU can get it,
>>> But maybe I miss something, but please let me know if other CPU can
>>> not get the interrupt.
>>
>>
>> There's only one watchdog device, so there's only one interrupt. I don't
>> know which CPU will get the interrupt, but the watchdog is not a per-CPU
>> device.
>>
> Plus, that one interrupt is not shared, and the driver returns
> IRQ_HANDLED even if the bit is not set. So _something_ is definitely
> wrong. Either the interrupt is shared, then it needs to be requested
> as shared and the handler should only return IRQ_HANDLED if it actually
> handles the interrupt. Or it is not shared and the handler should always
> handle it.
I have thought about this again, For now, I did not find any reason to
keep that "if (status & SBSA_GWDT_WCS_WS0)"
So you are right, I should delete it.
and for IRQF_TIMER, I will delete it.
Thanks for your correction.
>
> Guenter
>
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Fu Wei
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