sbsa_gwdt: Calculate timeout with 64-bit math

Commit abd3ac7902fb ("watchdog: sbsa: Support architecture version 1")
introduced new timer math for watchdog revision 1 with the 48 bit offset
register.

The gwdt->clk and timeout are u32, but the argument being calculated is
u64. Without a cast, the compiler performs u32 operations, truncating
intermediate steps, resulting in incorrect values.

A watchdog revision 1 implementation with a gwdt->clk of 1GHz and a
timeout of 600s writes 3647256576 to the one shot watchdog instead of
300000000000, resulting in the watchdog firing in 3.6s instead of 600s.

Force u64 math by casting the first argument (gwdt->clk) as a u64. Make
the order of operations explicit with parenthesis.

Fixes: abd3ac7902fb ("watchdog: sbsa: Support architecture version 1")
Reported-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com>
Signed-off-by: Darren Hart <darren@os.amperecomputing.com>
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-watchdog@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: <stable@vger.kernel.org> # 5.14.x
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/7d1713c5ffab19b0f3de796d82df19e8b1f340de.1695286124.git.darren@os.amperecomputing.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it was merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230726233302.3812749-1-robh@kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: sbsa: Test WDOG_HW_RUNNING bit in suspend and resume

If the sbsa_gwdt is enabled by BIOS, the kernel set WDOG_HW_RUNNING bit
and keep it alive before anyone else would open it. When system suspend,
the sbsa_gwdt would not be disabled because WDOG_ACTIVE is not set. Then
the sbsa_gwdt would reach timeout since no one touch it during system
suspend.

To solve this, just test WDOG_HW_RUNNING bit in suspend and disable the
sbsa_gwdt if the bit is set, then reopen it accordingly in resume
process.

Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230301113702.76437-1-wangwensheng4@huawei.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: sbsa_wdog: Make sure the timeout programming is within the limits

Make sure to honour the max_hw_heartbeat_ms while programming the timeout
value to WOR. Clamp the timeout passed to sbsa_gwdt_set_timeout() to
make sure the programmed value is within the permissible range.

Fixes: abd3ac7902fb ("watchdog: sbsa: Support architecture version 1")

Signed-off-by: George Cherian <george.cherian@marvell.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230209021117.1512097-1-george.cherian@marvell.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: sbsa: drop unneeded MODULE_ALIAS

The MODULE_DEVICE_TABLE already creates proper alias for platform
driver. Having another MODULE_ALIAS causes the alias to be duplicated.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210917092024.19323-1-krzysztof.kozlowski@canonical.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: sbsa: only use 32-bit accessors

SBSA says of the generic watchdog:

All registers are 32 bits in size and should be accessed using 32-bit
reads and writes. If an access size other than 32 bits is used then
the results are IMPLEMENTATION DEFINED.

and for qemu, the implementation will only allow 32-bit accesses
resulting in a synchronous external abort when configuring the watchdog.
Use lo_hi_* accessors rather than a readq/writeq.

Fixes: abd3ac7902fb ("watchdog: sbsa: Support architecture version 1")
Signed-off-by: Jamie Iles <quic_jiles@quicinc.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Link: https://lore.kernel.org/r/20210903112101.493552-1-quic_jiles@quicinc.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: sbsa: Support architecture version 1

For Armv8.6, The frequency of CNTFRQ_EL0 is standardized to a
frequency of 1GHz, so Arm Base System Architecture 1.0[1] has
introduced watchdog revision 1 that increases the length the
watchdog offset register to 48 bit, while other operation of
the watchdog remains the same.

The driver can determine which version of the watchdog is
implemented through the watchdog interface identification
register (W_IID). If the version is 0x1, the watchdog
offset register will be 48 bit, otherwise it will be 32 bit.

[1] https://developer.arm.com/documentation/den0094/latest

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Al Stone <al.stone@linaro.org>
Cc: Jianchao Hu <hujianchao@hisilicon.com>
Cc: Huiqiang Wang <wanghuiqiang@huawei.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1621253408-23401-1-git-send-email-zhangshaokun@hisilicon.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 294

Based on 2 normalized pattern(s):

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

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation this program is distributed in the hope
that it [would] 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

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 9 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.804956444@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

watchdog: sbsa_gwdt: Convert to use device managed functions and other improvements

Use device managed functions to simplify error handling, reduce
source code size, improve readability, and reduce the likelyhood of bugs.
Other improvements as listed below.

The conversion was done automatically with coccinelle using the
following semantic patches. The semantic patches and the scripts
used to generate this commit log are available at
https://github.com/groeck/coccinelle-patches

- Drop assignments to otherwise unused variables
- Drop empty remove function
- Use local variable 'struct device *dev' consistently
- Use devm_watchdog_register_driver() to register watchdog device
- Replace shutdown function with call to watchdog_stop_on_reboot()

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: Convert to use devm_platform_ioremap_resource

Use devm_platform_ioremap_resource to reduce source code size,
improve readability, and reduce the likelyhood of bugs.

The conversion was done automatically with coccinelle using the
following semantic patch.

@r@
identifier res, pdev;
expression a;
expression index;
expression e;
@@

<+...
- res = platform_get_resource(pdev, IORESOURCE_MEM, index);
- a = devm_ioremap_resource(e, res);
+ a = devm_platform_ioremap_resource(pdev, index);
...+>

@depends on r@
identifier r.res;
@@
- struct resource *res;
... when != res

@@
identifier res, pdev;
expression index;
expression a;
@@
- struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, index);
- a = devm_ioremap_resource(&pdev->dev, res);
+ a = devm_platform_ioremap_resource(pdev, index);

Cc: Joel Stanley <joel@jms.id.au>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Baruch Siach <baruch@tkos.co.il>
Cc: Keguang Zhang <keguang.zhang@gmail.com>
Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Avi Fishman <avifishman70@gmail.com>
Cc: Nancy Yuen <yuenn@google.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Sylvain Lemieux <slemieux.tyco@gmail.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Barry Song <baohua@kernel.org>
Cc: Orson Zhai <orsonzhai@gmail.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Marc Gonzalez <marc.w.gonzalez@free.fr>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Acked-by: Michal Simek <michal.simek@xilinx.com> (cadence/xilinx wdts)
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog/sbsa: Use arch_timer_read_counter instead of arch_counter_get_cntvct

Only arch_timer_read_counter will guarantee that workarounds are
applied. So let's use this one instead of arch_counter_get_cntvct.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

watchdog: sbsa: use 32-bit read for WCV

According to SBSA spec v3.1 section 5.3:
All registers are 32 bits in size and should be accessed using
32-bit reads and writes. If an access size other than 32 bits
is used then the results are IMPLEMENTATION DEFINED.
[...]
The Generic Watchdog is little-endian

The current code uses readq to read the watchdog compare register
which does a 64-bit access. This fails on ThunderX2 which does not
implement 64-bit access to this register.

Fix this by using lo_hi_readq() that does two 32-bit reads.

Signed-off-by: Jayachandran C <jnair@caviumnetworks.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: constify watchdog_ops structures

Declare watchdog_ops structures as const as they are only stored in the
ops field of a watchdog_device structure. This field is of type const, so
watchdog_ops structures having this property can be made const too.
Done using Coccinelle:

@r disable optional_qualifier@
identifier x;
position p;
@@
static struct watchdog_ops x@p={...};

@ok@
struct watchdog_device w;
identifier r.x;
position p;
@@
w.ops=&x@p;

@bad@
position p != {r.p,ok.p};
identifier r.x;
@@
x@p

@depends on !bad disable optional_qualifier@
identifier r.x;
@@
+const
struct watchdog_ops x;

File size details before and after patching.
First line of every .o file shows the file size before patching
and second line shows the size after patching.

text data bss dec hex filename

1340 544 0 1884 75c drivers/watchdog/bcm_kona_wdt.o
1436 440 0 1876 754 drivers/watchdog/bcm_kona_wdt.o

1176 544 4 1724 6bc drivers/watchdog/digicolor_wdt.o
1272 440 4 1716 6b4 drivers/watchdog/digicolor_wdt.o

925 580 89 1594 63a drivers/watchdog/ep93xx_wdt.o
1021 476 89 1586 632 drivers/watchdog/ep93xx_wdt.o

4932 288 17 5237 1475 drivers/watchdog/s3c2410_wdt.o
5028 192 17 5237 1475 drivers/watchdog/s3c2410_wdt.o

1977 292 1 2270 8de drivers/watchdog/sama5d4_wdt.o
2073 196 1 2270 8de drivers/watchdog/sama5d4_wdt.o

1375 484 1 1860 744 drivers/watchdog/sirfsoc_wdt.o
1471 380 1 1852 73c drivers/watchdog/sirfsoc_wdt.o

Size remains the same for the files drivers/watchdog/diag288_wdt.o
drivers/watchdog/asm9260_wdt.o and drivers/watchdog/atlas7_wdt.o

The following .o files did not compile:
drivers/watchdog/sun4v_wdt.o, drivers/watchdog/sbsa_gwdt.o,
drivers/watchdog/rt2880_wdt.o, drivers/watchdog/booke_wdt.o
drivers/watchdog/mt7621_wdt.o

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

watchdog: constify watchdog_info structures

Declare watchdog_info structures as const as they are only stored in the
info field of watchdog_device structures. This field is of type const
struct watchdog_info *, so watchdog_info structures having this property
can be declared const too.
Done using Coccinelle:

@r1 disable optional_qualifier@
identifier i;
position p;
@@
static struct watchdog_info i@p={...};

@ok@
identifier r1.i;
position p;
struct watchdog_device obj;
@@
obj.info=&i@p;

@bad@
position p!={r1.p,ok.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct watchdog_info i;

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

watchdog: sbsa: Drop status function

The watchdog status function is supposed to return WDIOF_ flags,
not internal status flags. The available WDIOF_ flags are now
returned by the watchdog core, so the status function in this driver
is unnecessary.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: sbsa: Set WDOG_HW_RUNNING, when watchdog is already running.

This patch uses the new flag WDOG_HW_RUNNING in driver.
According to the definition of this flag, it should be set,
if watchdog is running after booting, before it's opened.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Fu Wei <fu.wei@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: sbsa: Use max_hw_heartbeat_ms instead of max_timeout

Using max_hw_heartbeat_ms instead of max_timeout gives the flexibility to
achieve higher user "timeout". Therefore, use this new infrastructure.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Fu Wei <fu.wei@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Watchdog: introduce ARM SBSA watchdog driver

According to Server Base System Architecture (SBSA) specification,
the SBSA Generic Watchdog has two stage timeouts: the first signal (WS0)
is for alerting the system by interrupt, the second one (WS1) is a real
hardware reset.
More details about the hardware specification of this device:
ARM DEN0029B - Server Base System Architecture (SBSA)

This driver can operate ARM SBSA Generic Watchdog as a single stage watchdog
or a two stages watchdog, it's set up by the module parameter "action".
In the single stage mode, when the timeout is reached, your system
will be reset by WS1. The first signal (WS0) is ignored.
In the two stages mode, when the timeout is reached, the first signal (WS0)
will trigger panic. If the system is getting into trouble and cannot be reset
by panic or restart properly by the kdump kernel(if supported), then the
second stage (as long as the first stage) will be reached, system will be
reset by WS1. This function can help administrator to backup the system
context info by panic console output or kdump.

This driver bases on linux kernel watchdog framework, so it can get
timeout from module parameter and FDT at the driver init stage.

Signed-off-by: Fu Wei <fu.wei@linaro.org>
Reviewed-by: Graeme Gregory <graeme.gregory@linaro.org>
Tested-by: Pratyush Anand <panand@redhat.com>
Acked-by: Timur Tabi <timur@codeaurora.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>