* [PATCH] MAINTAINERS: KVM: Include maintainer profile
From: Krzysztof Kozlowski @ 2026-05-18 10:41 UTC (permalink / raw)
To: Sean Christopherson, Paolo Bonzini, Jonathan Corbet, Shuah Khan,
kvm, workflows, linux-doc, linux-kernel
Cc: Krzysztof Kozlowski
No dedicated KVM maintainers are returned by get_maintainers.pl for the
subsystem maintainer profile, thus patches changing that file miss
the actual owners of the file.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
---
MAINTAINERS | 1 +
1 file changed, 1 insertion(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index a6553271e19a..7a65b220d93f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14205,6 +14205,7 @@ L: kvm@vger.kernel.org
S: Supported
P: Documentation/process/maintainer-kvm-x86.rst
T: git git://git.kernel.org/pub/scm/virt/kvm/kvm.git
+F: Documentation/process/maintainer-kvm-x86.rst
F: arch/x86/include/asm/kvm*
F: arch/x86/include/asm/svm.h
F: arch/x86/include/asm/vmx*.h
--
2.51.0
^ permalink raw reply related
* [PATCH] MAINTAINERS: nvdimm: Include maintainer profile
From: Krzysztof Kozlowski @ 2026-05-18 10:43 UTC (permalink / raw)
To: Dan Williams, Vishal Verma, Dave Jiang, Ira Weiny,
Jonathan Corbet, Shuah Khan, nvdimm, linux-doc, linux-kernel
Cc: Krzysztof Kozlowski
No dedicated NVDIMM maintainers are returned by get_maintainers.pl for
the subsystem maintainer profile, thus patches changing that file miss
the actual owners of the file.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
---
MAINTAINERS | 1 +
1 file changed, 1 insertion(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 7a65b220d93f..294909f6d488 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14751,6 +14751,7 @@ S: Supported
Q: https://patchwork.kernel.org/project/linux-nvdimm/list/
P: Documentation/nvdimm/maintainer-entry-profile.rst
T: git git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm.git
+F: Documentation/nvdimm/maintainer-entry-profile.rst
F: drivers/acpi/nfit/*
F: drivers/nvdimm/*
F: include/linux/libnvdimm.h
--
2.51.0
^ permalink raw reply related
* Re: [PATCH v5 01/13] iio: core: validate file offset in iio_debugfs_write_reg()
From: Rodrigo Alencar @ 2026-05-18 10:43 UTC (permalink / raw)
To: rodrigo.alencar, linux-iio, devicetree, linux-kernel, linux-doc,
linux-hardening
Cc: Lars-Peter Clausen, Michael Hennerich, Jonathan Cameron,
David Lechner, Andy Shevchenko, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Philipp Zabel, Jonathan Corbet, Shuah Khan,
Kees Cook, Gustavo A. R. Silva, sashiko-bot
In-Reply-To: <20260517-ad9910-iio-driver-v5-1-31599c88314a@analog.com>
On 26/05/17 07:04PM, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
> - [High] The `*ppos != 0` check introduces a functional regression for sequential writes, masking the true bug which is the inappropriate use of `simple_write_to_buffer()`.
> - [High] Unpatched uninitialized stack memory reads in other IIO drivers caused by the identical anti-pattern.
> --
>
> commit 7c5ddbc34738b9e84e226b9906348d61e3569bf4
> Author: Rodrigo Alencar <rodrigo.alencar@analog.com>
>
> iio: core: validate file offset in iio_debugfs_write_reg()
>
> This patch adds a check to ensure that the file offset is zero in
> iio_debugfs_write_reg() before calling simple_write_to_buffer(). This is
> intended to prevent leaving the start of the buffer uninitialized if a write
> occurs at a non-zero offset.
>
> > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> > index bd6f4f9f45330..e587aca79b8e7 100644
> > --- a/drivers/iio/industrialio-core.c
> > +++ b/drivers/iio/industrialio-core.c
> > @@ -419,7 +419,7 @@ static ssize_t iio_debugfs_write_reg(struct file *file,
> > char buf[80];
> > int ret;
> >
> > - if (count >= sizeof(buf))
> > + if (count >= sizeof(buf) || *ppos != 0)
>
> Does this cause a functional regression for sequential writes?
>
> If a user writes multiple commands to the same open file descriptor, for
> example using (echo "cmd1"; echo "cmd2") > direct_reg_access, the first
> write advances the file position. This means *ppos will be non-zero on the
> second write, causing it to fail with -EINVAL.
>
> Before simple_write_to_buffer() was introduced, the code used
> copy_from_user() and ignored *ppos, correctly treating every write() call
> as a distinct command starting at the beginning of the buffer.
>
> Since simple_write_to_buffer() is designed for stateful linear memory buffers
> rather than stateless command endpoints using local stack arrays, would it be
> better to revert the use of simple_write_to_buffer() entirely and use
> copy_from_user() or strndup_user() to parse each write independently?
>
> Additionally, does this leave a similar pattern unpatched in other IIO
> drivers?
>
> While this patch addresses the issue in iio_debugfs_write_reg(), the same
> pattern of using simple_write_to_buffer() into a local stack array still
> exists in other locations:
>
> 1. iio_backend_debugfs_write_reg() in drivers/iio/industrialio-backend.c
> 2. ad3552r_hs_write_data_source() in drivers/iio/dac/ad3552r-hs.c
>
> Both functions use simple_write_to_buffer() into uninitialized local stack
> arrays without checking *ppos.
>
> Furthermore, ad9467_chan_test_mode_write() in drivers/iio/adc/ad9467.c
> uses the same pattern. While the buffer is zero-initialized there,
> sequential writes will still be functionally broken.
>
> > return -EINVAL;
This was me trying to fix an issue and maybe creating another.
Probably I would just drop this, and leave this to be handled later.
At least it was good to indicate that such issue exist.
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/20260517-ad9910-iio-driver-v5-0-31599c88314a@analog.com?part=1
--
Kind regards,
Rodrigo Alencar
^ permalink raw reply
* Re: [PATCH v5 4/4] driver core: platform: set mod_name in driver registration
From: Greg Kroah-Hartman @ 2026-05-18 10:49 UTC (permalink / raw)
To: Shashank Balaji
Cc: Suzuki K Poulose, James Clark, Alexander Shishkin,
Rafael J. Wysocki, Danilo Krummrich, Miguel Ojeda, Boqun Feng,
Gary Guo, Björn Roy Baron, Benno Lossin, Andreas Hindborg,
Alice Ryhl, Trevor Gross, Jonathan Corbet, Shuah Khan,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Mike Leach, Leo Yan, Thierry Reding,
Jonathan Hunter, Rahul Bukte, linux-kernel, coresight,
linux-arm-kernel, driver-core, rust-for-linux, linux-doc,
Daniel Palmer, Tim Bird, linux-modules, linux-tegra, Sumit Gupta
In-Reply-To: <agrqvIiNWrYtGvTk@JPC00244420>
On Mon, May 18, 2026 at 07:32:28PM +0900, Shashank Balaji wrote:
> On Mon, May 18, 2026 at 12:27:13PM +0200, Greg Kroah-Hartman wrote:
> > On Mon, May 18, 2026 at 07:20:00PM +0900, Shashank Balaji wrote:
> > > Pass KBUILD_MODNAME through the driver registration macro so that
> > > the driver core can create the module symlink in sysfs for built-in
> > > drivers, and fixup all callers.
> > >
> > > The Rust platform adapter is updated to pass the module name through to the new
> > > parameter.
> > >
> > > Tested on qemu with:
> > > - x86 defconfig + CONFIG_RUST
> > > - arm64 defconfig + CONFIG_RUST + CONFIG_CORESIGHT stuff
> > >
> > > Examples after this patch:
> > >
> > > /sys/bus/platform/drivers/...
> > > coresight-itnoc/module -> coresight_tnoc
> > > coresight-static-tpdm/module -> coresight_tpdm
> > > coresight-catu-platform/module -> coresight_catu
> > > serial8250/module -> 8250
> > > acpi-ged/module -> acpi
> > > vmclock/module -> ptp_vmclock
> > >
> > > Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
> > > Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
> > > Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
> > > ---
> > > This patch depends on patches 1, 2, 3
> > > ---
> > > Documentation/driver-api/driver-model/platform.rst | 3 ++-
> > > drivers/base/platform.c | 21 ++++++++++++++-------
> > > drivers/hwtracing/coresight/coresight-core.c | 5 +++--
> > > include/linux/coresight.h | 5 +++--
> > > include/linux/platform_device.h | 17 +++++++++--------
> > > rust/kernel/platform.rs | 4 +++-
> > > 6 files changed, 34 insertions(+), 21 deletions(-)
> > >
> > > diff --git a/Documentation/driver-api/driver-model/platform.rst b/Documentation/driver-api/driver-model/platform.rst
> > > index cf5ff48d3115..9673470bded2 100644
> > > --- a/Documentation/driver-api/driver-model/platform.rst
> > > +++ b/Documentation/driver-api/driver-model/platform.rst
> > > @@ -70,7 +70,8 @@ Kernel modules can be composed of several platform drivers. The platform core
> > > provides helpers to register and unregister an array of drivers::
> > >
> > > int __platform_register_drivers(struct platform_driver * const *drivers,
> > > - unsigned int count, struct module *owner);
> > > + unsigned int count, struct module *owner,
> > > + const char *mod_name);
> >
> > Why can't you just use the owner->name value instead? They are always
> > the same here, right?
>
> owner is NULL for built-in modules.
Ah, sorry, forgot about that.
^ permalink raw reply
* Re: [PATCH v6 1/2] usb: xhci-pci: add AMD Promontory 21 PCI glue
From: Guenter Roeck @ 2026-05-18 10:55 UTC (permalink / raw)
To: Michal Pecio, Jihong Min
Cc: Greg Kroah-Hartman, Mathias Nyman, Jonathan Corbet, Shuah Khan,
Mario Limonciello, Basavaraj Natikar, linux-usb, linux-hwmon,
linux-doc, linux-pci, linux-kernel, Mario Limonciello (AMD),
Yaroslav Isakov
In-Reply-To: <20260517232147.34931718.michal.pecio@gmail.com>
On 5/17/26 14:21, Michal Pecio wrote:
> On Sun, 17 May 2026 22:04:06 +0900, Jihong Min wrote:
>> AMD Promontory 21 (PROM21) xHCI controllers use generic xHCI
>> operation, but the PCI function also exposes optional
>> controller-specific sensor functionality. Add a small PROM21 PCI glue
>> driver for AMD 1022:43fc and 1022:43fd controllers.
>>
>> The driver delegates USB host operation to the common xhci-pci core,
>> collects the parent-provided MMIO resource data, and creates a "hwmon"
>> auxiliary device for optional child drivers. Failure to create the
>> auxiliary device is logged but does not fail the xHCI probe, since the
>> auxiliary device is only needed for sensor support.
>>
>> Make the PROM21 PCI glue a hidden Kconfig tristate that follows
>> USB_XHCI_PCI. This keeps the glue built in with a built-in xhci-pci core
>> and builds it as a module with a modular xhci-pci core. A built-in
>> xhci-pci core must not hand PROM21 controllers to a PROM21 glue driver
>> that is only available as a module, otherwise USB behind those controllers
>> can be unavailable during initramfs and PROM21 temperature sensor support
>> may not appear until the controller is rebound after the module loads.
>>
>> Assisted-by: Codex:gpt-5.5
>> Signed-off-by: Jihong Min <hurryman2212@gmail.com>
>> Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
>> Tested-by: Yaroslav Isakov <yaroslav.isakov@gmail.com>
>> ---
>> drivers/usb/host/Kconfig | 7 +
>> drivers/usb/host/Makefile | 1 +
>> drivers/usb/host/xhci-pci-prom21.c | 136 ++++++++++++++++++
>> drivers/usb/host/xhci-pci.c | 11 ++
>> drivers/usb/host/xhci-pci.h | 3 +
>> include/linux/platform_data/usb-xhci-prom21.h | 22 +++
>> 6 files changed, 180 insertions(+)
>> create mode 100644 drivers/usb/host/xhci-pci-prom21.c
>> create mode 100644 include/linux/platform_data/usb-xhci-prom21.h
>>
>> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
>> index 0a277a07cf70..89bf262235e1 100644
>> --- a/drivers/usb/host/Kconfig
>> +++ b/drivers/usb/host/Kconfig
>> @@ -42,6 +42,13 @@ config USB_XHCI_PCI
>> depends on USB_PCI
>> default y
>>
>> +config USB_XHCI_PCI_PROM21
>> + tristate
>> + depends on X86
>> + depends on USB_XHCI_PCI
>> + default USB_XHCI_PCI
>> + select AUXILIARY_BUS
>> +
>
> Instead of the X86 heuristic, would it be possible to build glue
> code if and only if SENSORS_PROM21_XHCI is enabled?
>
> This seems to work:
>
> config SENSORS_PROM21_XHCI
> tristate "AMD Promontory 21 xHCI temperature sensor"
> - depends on USB_XHCI_PCI_PROM21
> + depends on USB_XHCI_PCI
>
> config USB_XHCI_PCI_PROM21
> tristate
> - depends on X86
> depends on USB_XHCI_PCI
> - default USB_XHCI_PCI
> + default USB_XHCI_PCI if SENSORS_PROM21_XHCI != 'n'
> select AUXILIARY_BUS
>
> I don't know if it's the best way, perhaps it would be preferable for
> the hwmon driver to select the glue, but then I'm not sure how to force
> glue to become 'y' when xhci-pci is 'y'.
>
Unless I am missing something, that would disable the entire controller
if the hwmon device is not enabled. That seems a bit draconian to me.
Guenter
^ permalink raw reply
* Re: [PATCH] nios2: remove the architecture
From: Peter Zijlstra @ 2026-05-18 10:57 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Ethan Nelson-Moore, linux-doc, devicetree, workflows, Linux-Arch,
dmaengine, linux-i2c, linux-iio, Netdev, linux-pci, linux-pwm,
linux-hardening, linux-kbuild, linux-csky@vger.kernel.org,
Jonathan Corbet, Shuah Khan, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Daniel Lezcano, Thomas Gleixner, Alex Shi,
Yanteng Si, Dongliang Mu, Hu Haowen, Dinh Nguyen, Kees Cook,
Oleg Nesterov, Will Deacon, Aneesh Kumar K.V (Arm), Andrew Morton,
Nicholas Piggin, Vinod Koul, Frank Li, Dave Penkler, Andi Shyti,
Jonathan Cameron, David Lechner, Nuno Sá, Andy Shevchenko,
Andrew Lunn, David S . Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, Lorenzo Pieralisi, Krzysztof Wilczyński,
Simon Schuster, Andreas Oetken
In-Reply-To: <d40b1e80-37fc-4c88-9d7f-dae6458efe6c@app.fastmail.com>
On Mon, May 18, 2026 at 11:29:48AM +0200, Arnd Bergmann wrote:
> On Mon, May 18, 2026, at 06:28, Ethan Nelson-Moore wrote:
> > The Nios II architecture is a soft-core architecture developed by
> > Altera (since acquired by Intel) and intended to run on their FPGAs.
> >
> > Licenses for the architecture have not been available for purchase
> > since 2024 [1], and support for it has been removed from GCC 15 [2],
> > Buildroot [3], and QEMU [4].
> >
> > Given all of these factors, it is time to remove Nios II support from
> > the kernel. The maintainer stated in 2024 that they were planning to do
> > so soon [5], but this did not come to pass.
> >
> > Remove Nios II support from the kernel and move the former maintainer
> > to CREDITS. Thank you, Dinh Nguyen, for maintaining Nios II support!
>
> Hi Ethan,
>
> We last discussed this a year ago when Simon Schuster mentioned[1]
> that Siemens Energy is still using NIOS-2 in production and would
> prefer to have this still included in Linux for at least another
> few years until the obligation for kernel updates ends.
Isn't that what we have LTS branches for?
^ permalink raw reply
* Re: [PATCH v6 2/2] hwmon: add AMD Promontory 21 xHCI temperature sensor support
From: Guenter Roeck @ 2026-05-18 10:58 UTC (permalink / raw)
To: Jihong Min, Greg Kroah-Hartman, Mathias Nyman
Cc: Jonathan Corbet, Shuah Khan, Mario Limonciello, Basavaraj Natikar,
linux-usb, linux-hwmon, linux-doc, linux-pci, linux-kernel,
Mario Limonciello (AMD), Yaroslav Isakov
In-Reply-To: <20260517130407.795157-3-hurryman2212@gmail.com>
On 5/17/26 06:04, Jihong Min wrote:
> Add an auxiliary-bus hwmon driver for the temperature sensor exposed by
> AMD Promontory 21 (PROM21) xHCI PCI functions. The driver binds to the
> "hwmon" auxiliary device published by the PROM21 xHCI PCI glue and
> exposes the sensor as temp1_input under the prom21_xhci hwmon device.
>
> The sensor is accessed through a PROM21 vendor index/data register pair
> in the xHCI PCI MMIO BAR. The driver consumes parent-provided MMIO data
> from the PROM21 PCI glue instead of inspecting the parent PCI driver's
> drvdata. The read path restores the previous vendor index value after
> sampling and does not runtime-resume the parent PCI device; reads from a
> suspended parent return -ENODATA.
>
> Document the supported device, register access, runtime PM behavior, and
> sysfs lookup method. The documentation also records the observation
> method used to identify the register pair and derive the conversion
> formula.
>
> Assisted-by: Codex:gpt-5.5
> Signed-off-by: Jihong Min <hurryman2212@gmail.com>
> Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
> Tested-by: Yaroslav Isakov <yaroslav.isakov@gmail.com>
For my reference:
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
I'll need an Acked-by: from a maintainer on the first patch to apply
both patches, or this patch can be applied through some other tree.
I am fine with both.
Thanks,
Guenter
^ permalink raw reply
* Re: [PATCH v5 06/13] iio: frequency: ad9910: initial driver implementation
From: Rodrigo Alencar @ 2026-05-18 11:45 UTC (permalink / raw)
To: rodrigo.alencar, linux-iio, devicetree, linux-kernel, linux-doc,
linux-hardening
Cc: Lars-Peter Clausen, Michael Hennerich, Jonathan Cameron,
David Lechner, Andy Shevchenko, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Philipp Zabel, Jonathan Corbet, Shuah Khan,
Kees Cook, Gustavo A. R. Silva
In-Reply-To: <20260517-ad9910-iio-driver-v5-6-31599c88314a@analog.com>
On 26/05/17 07:20PM, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 6 potential issue(s) to consider:
> - [High] Incorrect usage of `device_property_read_u32_array` causes single-value property `output-range-microamp` to be ignored.
> - [High] VCO_SEL field is incorrectly set to an out-of-bounds value (7) when the PLL is bypassed.
> - [High] Stack out-of-bounds read in `ad9910_profile_set()` triggered by unvalidated GPIO descriptor count.
> - [High] Missing resource teardown: device reset line is never asserted on driver removal.
> - [Medium] PLL multiplier clamping logic violates the hardware's minimum VCO operating frequency.
> - [Medium] Missing hardware initialization delay after reset deassertion can cause SPI communications to fail.
> --
>
> commit fb6e130c7d866653f35ab965acf927500a84756c
> Author: Rodrigo Alencar <rodrigo.alencar@analog.com>
>
> iio: frequency: ad9910: initial driver implementation
>
> Add the core AD9910 DDS driver infrastructure with single tone mode
> support. This includes SPI register access, profile management via GPIO
> pins, PLL/DAC configuration from firmware properties, and single tone
> frequency/phase/amplitude control through IIO attributes.
>
> > diff --git a/drivers/iio/frequency/ad9910.c b/drivers/iio/frequency/ad9910.c
> > new file mode 100644
> > index 0000000000000..c7b1e474c92df
> > --- /dev/null
> > +++ b/drivers/iio/frequency/ad9910.c
> [ ... ]
> > +static int ad9910_set_sysclk_freq(struct ad9910_state *st, u32 freq_hz,
> > + bool update)
> > +{
> [ ... ]
> > + tmp32 = clamp(tmp32, DIV_ROUND_UP(AD9910_PLL_OUT_MIN_FREQ_HZ, refclk_freq_hz),
> > + AD9910_PLL_OUT_MAX_FREQ_HZ / refclk_freq_hz);
> > + tmp32 = clamp(tmp32, AD9910_PLL_MIN_N, AD9910_PLL_MAX_N);
> > + sysclk_freq_hz = refclk_freq_hz * tmp32;
>
> Is it possible for this second clamp to drop the multiplier below the
> minimum frequency constraint? If the input reference clock is 3.2 MHz,
> the first clamp would raise the multiplier to 132 to reach 420 MHz, but
> the second clamp limits it to 127. This results in a VCO frequency of
> 406.4 MHz, violating the hardware minimum. Should the driver return
> -ERANGE instead if the bounds cannot be satisfied?
I suppose that would not be problematic as the PLL does accept that input
frequency. Even though the VCO might not be designed for frequencies as low as
406.4 MHz, we are doing the best effort here to get a proper configuration.
> [ ... ]
> > + } else {
> > + tmp32 = DIV_ROUND_CLOSEST(refclk_freq_hz, freq_hz);
> > + tmp32 = clamp(tmp32, 1U, 2U);
> > + sysclk_freq_hz = refclk_freq_hz / tmp32;
> > + tmp32 = AD9910_CFR3_VCO_SEL_MSK |
> > + FIELD_PREP(AD9910_CFR3_REFCLK_DIV_BYPASS_MSK, tmp32 % 2);
> > + ret = ad9910_reg32_update(st, AD9910_REG_CFR3,
> > + AD9910_CFR3_VCO_SEL_MSK |
> > + AD9910_CFR3_REFCLK_DIV_BYPASS_MSK,
> > + tmp32, update);
>
> Does setting tmp32 with AD9910_CFR3_VCO_SEL_MSK cause the update function
> to write an out-of-bounds value here? Because tmp32 contains the entire
> mask, the underlying field will be set to 7, but the valid range for the
> vco sel field is 0 to 5.
No, 6 and 7 means PLL bypassed (Table 8 in the datasheet). Also, 7 is the
default value of that bitfield.
> [ ... ]
> > +static int ad9910_profile_set(struct ad9910_state *st, u8 profile)
> > +{
> > + DECLARE_BITMAP(values, BITS_PER_TYPE(profile));
> > +
> > + st->profile = profile;
> > + values[0] = profile;
> > + gpiod_multi_set_value_cansleep(st->gpio_profile, values);
> > +
> > + return 0;
> > +}
>
> Could this cause an out-of-bounds read on the stack? The values bitmap is
> sized using BITS_PER_TYPE(profile), which allocates space for 1 unsigned
> long. If the device tree provides more profile gpios than fit in an unsigned
> long, gpiod_multi_set_value_cansleep() might read past the end of the bitmap
> when iterating over the descriptors.
well, profile-gpios are at most 3 pins. I'll see to constraint that in the
probe function.
> [ ... ]
> > +static int ad9910_parse_fw(struct ad9910_state *st)
> > +{
> [ ... ]
> > + tmp[1] = AD9910_DAC_IOUT_DEFAULT_uA;
> > + device_property_read_u32_array(dev, "output-range-microamp", tmp,
> > + ARRAY_SIZE(tmp));
>
> Will this properly read a single-value property? Because ARRAY_SIZE(tmp)
> is passed as the expected element count, device_property_read_u32_array()
> might return -EOVERFLOW and leave the tmp array unmodified if only one
> value is present in the device tree, causing the property to be silently
> ignored.
Ignoring those misconfigurations might be ok too. One can refer to the
bindings to have a proper reference.
>
> [ ... ]
> > +static int ad9910_setup(struct device *dev, struct ad9910_state *st,
> > + struct reset_control *dev_rst)
> > +{
> > + int ret;
> > +
> > + ret = reset_control_deassert(dev_rst);
> > + if (ret)
> > + return ret;
> > +
>
> Is a teardown action missing for the device reset here? Without adding a
> managed action to assert the reset line, the hardware might remain active
> after the driver is unloaded or if a subsequent setup step fails.
I'd say it can't remain active with the power down pin being handled already.
> Might this also require a hardware delay before the first spi write? The
> datasheet specifies waiting for the internal state machine to become ready
> after a low-to-high transition on the reset line. On fast hosts, the
> immediate spi access might be ignored.
Could not find that info in the datasheet. What is says is that the reset
clears memory elements, e.g. registers are set to default values.
> > + ret = ad9910_reg32_write(st, AD9910_REG_CFR1,
> > + (st->spi->mode & SPI_3WIRE ? 0 :
> > + AD9910_CFR1_SDIO_INPUT_ONLY_MSK), false);
> > + if (ret)
> > + return ret;
>
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/20260517-ad9910-iio-driver-v5-0-31599c88314a@analog.com?part=6
--
Kind regards,
Rodrigo Alencar
^ permalink raw reply
* Re: [PATCH mm-unstable v17 02/14] mm/khugepaged: generalize alloc_charge_folio()
From: Usama Arif @ 2026-05-18 11:55 UTC (permalink / raw)
To: Nico Pache
Cc: Usama Arif, linux-doc, linux-kernel, linux-mm, linux-trace-kernel,
akpm, anshuman.khandual, apopple, baohua, baolin.wang, byungchul,
catalin.marinas, cl, corbet, dave.hansen, david, dev.jain, gourry,
hannes, hughd, jack, jackmanb, jannh, jglisse, joshua.hahnjy, kas,
lance.yang, liam, ljs, mathieu.desnoyers, matthew.brost, mhiramat,
mhocko, peterx, pfalcato, rakie.kim, raquini, rdunlap,
richard.weiyang, rientjes, rostedt, rppt, ryan.roberts, shivankg,
sunnanyong, surenb, thomas.hellstrom, tiwai, usamaarif642, vbabka,
vishal.moola, wangkefeng.wang, will, willy, yang, ying.huang, ziy,
zokeefe
In-Reply-To: <20260511185817.686831-3-npache@redhat.com>
On Mon, 11 May 2026 12:58:02 -0600 Nico Pache <npache@redhat.com> wrote:
> From: Dev Jain <dev.jain@arm.com>
>
> Pass order to alloc_charge_folio() and update mTHP statistics.
>
> Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
> Reviewed-by: Lance Yang <lance.yang@linux.dev>
> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
> Reviewed-by: Zi Yan <ziy@nvidia.com>
> Acked-by: Usama Arif <usama.arif@linux.dev>
> Acked-by: David Hildenbrand (Arm) <david@kernel.org>
> Signed-off-by: Dev Jain <dev.jain@arm.com>
> Co-developed-by: Nico Pache <npache@redhat.com>
> Signed-off-by: Nico Pache <npache@redhat.com>
> ---
> Documentation/admin-guide/mm/transhuge.rst | 8 ++++++++
> include/linux/huge_mm.h | 2 ++
> mm/huge_memory.c | 4 ++++
> mm/khugepaged.c | 17 +++++++++++------
> 4 files changed, 25 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
> index 5fbc3d89bb07..c51932e6275d 100644
> --- a/Documentation/admin-guide/mm/transhuge.rst
> +++ b/Documentation/admin-guide/mm/transhuge.rst
> @@ -639,6 +639,14 @@ anon_fault_fallback_charge
> instead falls back to using huge pages with lower orders or
> small pages even though the allocation was successful.
>
> +collapse_alloc
> + is incremented every time a huge page is successfully allocated for a
> + khugepaged collapse.
> +
> +collapse_alloc_failed
> + is incremented every time a huge page allocation fails during a
> + khugepaged collapse.
> +
> zswpout
> is incremented every time a huge page is swapped out to zswap in one
> piece without splitting.
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 2949e5acff35..ba7ae6808544 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -128,6 +128,8 @@ enum mthp_stat_item {
> MTHP_STAT_ANON_FAULT_ALLOC,
> MTHP_STAT_ANON_FAULT_FALLBACK,
> MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE,
> + MTHP_STAT_COLLAPSE_ALLOC,
> + MTHP_STAT_COLLAPSE_ALLOC_FAILED,
> MTHP_STAT_ZSWPOUT,
> MTHP_STAT_SWPIN,
> MTHP_STAT_SWPIN_FALLBACK,
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index e9d499da0ac7..05f482a72a89 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -699,6 +699,8 @@ static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
> DEFINE_MTHP_STAT_ATTR(anon_fault_alloc, MTHP_STAT_ANON_FAULT_ALLOC);
> DEFINE_MTHP_STAT_ATTR(anon_fault_fallback, MTHP_STAT_ANON_FAULT_FALLBACK);
> DEFINE_MTHP_STAT_ATTR(anon_fault_fallback_charge, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE);
> +DEFINE_MTHP_STAT_ATTR(collapse_alloc, MTHP_STAT_COLLAPSE_ALLOC);
> +DEFINE_MTHP_STAT_ATTR(collapse_alloc_failed, MTHP_STAT_COLLAPSE_ALLOC_FAILED);
> DEFINE_MTHP_STAT_ATTR(zswpout, MTHP_STAT_ZSWPOUT);
> DEFINE_MTHP_STAT_ATTR(swpin, MTHP_STAT_SWPIN);
> DEFINE_MTHP_STAT_ATTR(swpin_fallback, MTHP_STAT_SWPIN_FALLBACK);
> @@ -764,6 +766,8 @@ static struct attribute *any_stats_attrs[] = {
> #endif
> &split_attr.attr,
> &split_failed_attr.attr,
> + &collapse_alloc_attr.attr,
> + &collapse_alloc_failed_attr.attr,
> NULL,
> };
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 979885694351..f0e29d5c7b1f 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -1068,21 +1068,26 @@ static enum scan_result __collapse_huge_page_swapin(struct mm_struct *mm,
> }
>
> static enum scan_result alloc_charge_folio(struct folio **foliop, struct mm_struct *mm,
> - struct collapse_control *cc)
> + struct collapse_control *cc, unsigned int order)
> {
> gfp_t gfp = (cc->is_khugepaged ? alloc_hugepage_khugepaged_gfpmask() :
> GFP_TRANSHUGE);
> int node = collapse_find_target_node(cc);
> struct folio *folio;
>
> - folio = __folio_alloc(gfp, HPAGE_PMD_ORDER, node, &cc->alloc_nmask);
> + folio = __folio_alloc(gfp, order, node, &cc->alloc_nmask);
> if (!folio) {
> *foliop = NULL;
> - count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
> + if (is_pmd_order(order))
> + count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
> + count_mthp_stat(order, MTHP_STAT_COLLAPSE_ALLOC_FAILED);
> return SCAN_ALLOC_HUGE_PAGE_FAIL;
> }
>
> - count_vm_event(THP_COLLAPSE_ALLOC);
> + if (is_pmd_order(order))
> + count_vm_event(THP_COLLAPSE_ALLOC);
> + count_mthp_stat(order, MTHP_STAT_COLLAPSE_ALLOC);
> +
The vmstat THP_COLLAPSE_ALLOC counter is pmd order only.
But after this we have
count_memcg_folio_events(folio, THP_COLLAPSE_ALLOC, 1);
which is not being guarded with is_pmd_order().
I think we want this to be pmd order only as well so that
the meaning of the vmstat and cgroup counter remains the same?
> if (unlikely(mem_cgroup_charge(folio, mm, gfp))) {
> folio_put(folio);
> *foliop = NULL;
> @@ -1118,7 +1123,7 @@ static enum scan_result collapse_huge_page(struct mm_struct *mm, unsigned long a
> */
> mmap_read_unlock(mm);
>
> - result = alloc_charge_folio(&folio, mm, cc);
> + result = alloc_charge_folio(&folio, mm, cc, HPAGE_PMD_ORDER);
> if (result != SCAN_SUCCEED)
> goto out_nolock;
>
> @@ -1899,7 +1904,7 @@ static enum scan_result collapse_file(struct mm_struct *mm, unsigned long addr,
> VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem);
> VM_BUG_ON(start & (HPAGE_PMD_NR - 1));
>
> - result = alloc_charge_folio(&new_folio, mm, cc);
> + result = alloc_charge_folio(&new_folio, mm, cc, HPAGE_PMD_ORDER);
> if (result != SCAN_SUCCEED)
> goto out;
>
> --
> 2.54.0
>
>
^ permalink raw reply
* [PATCH v4 00/10] ACPI: APEI: share GHES CPER helpers and add DT FFH provider
From: Ahmed Tiba @ 2026-05-18 11:57 UTC (permalink / raw)
To: rafael, bp, saket.dumbre, will, xueshuai, mchehab, krzk+dt, dave,
conor+dt, vishal.l.verma, jic23, corbet, guohanjun, dave.jiang,
catalin.marinas, lenb, tony.luck, skhan, djbw, alison.schofield,
ira.weiny, robh
Cc: Ahmed Tiba, devicetree, linux-acpi, linux-doc, Dmitry.Lamerov,
linux-cxl, Michael.Zhao2, acpica-devel, linux-kernel,
linux-arm-kernel, linux-edac
This is v4 of the GHES refactor series. Compared to v3, it mainly
updates the shared header comment and the DT binding/description
for the firmware-owned CPER buffer.
Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
Changes in v4:
- Reworded the ghes_cper.h header comment and kept the original copyrights.
- Fixed the ghes_cper.h W=1 warnings by limiting the ACPI
fixmap-based declarations to the ACPI build path.
- Updated the DT binding to describe the CPER buffer
as firmware-owned shared memory.
- Described the optional ack area as a second memory-region entry.
- Updated the DT example accordingly.
- Link to v3: https://lore.kernel.org/r/20260318-topics-ahmtib01-ras_ffh_arm_internal_review-v3-0-48e6a1c249ef@arm.com
Changes in v3:
- Fixed the new ghes_cper.h header comment and kept the original
copyrights.
- Added <linux/bitfield.h> to fix the kernel test robot build failure.
- Renamed the binding/compatible and DT-side naming to ras-cper.
- Switched the DT provider to generic firmware property accessors.
- Replaced atomic source IDs with IDA.
- Updated IRQ/error/resource handling as suggested in review
(platform_get_irq(), dev_err_probe(), devm platform ioremap
helpers).
- Removed the ARM64 dependency and fixed Kconfig/build coverage.
- Clarified comments and kept the early move patches mechanical.
- Link to v2: https://lore.kernel.org/r/20260220-topics-ahmtib01-ras_ffh_arm_internal_review-v2-0-347fa2d7351b@arm.com
Changes in v2:
- Dropped the proposed "estatus core" and kept GHES naming/flow intact
(per Borislav Petkov).
- Re-sliced the series into smaller mechanical steps (per Mauro Carvalho Chehab).
- Minor DT binding fixes based on Krzysztof Kozlowski's feedback.
- Removed fixmap slot usage from the DT FFH driver (per Will Deacon).
Series structure:
- Patches 1-8 are mechanical moves only and do not change behavior.
- Patch 9 wires the shared helpers back into GHES.
- The DT firmware-first CPER buffer provider is added in the final patches.
- "ACPI: APEI: introduce GHES helper" is internal build glue only
and does not introduce a new user-visible configuration option.
- Link to v1: https://lore.kernel.org/r/20251217112845.1814119-1-ahmed.tiba@arm.com
---
Ahmed Tiba (10):
ACPI: APEI: GHES: share macros via a private header
ACPI: APEI: GHES: move CPER read helpers
ACPI: APEI: GHES: move GHESv2 ack and alloc helpers
ACPI: APEI: GHES: move estatus cache helpers
ACPI: APEI: GHES: move vendor record helpers
ACPI: APEI: GHES: move CXL CPER helpers
ACPI: APEI: introduce GHES helper
ACPI: APEI: share GHES CPER helpers
dt-bindings: firmware: add arm,ras-cper
RAS: add firmware-first CPER provider
Documentation/admin-guide/RAS/main.rst | 18 +
.../devicetree/bindings/firmware/arm,ras-cper.yaml | 71 ++
MAINTAINERS | 6 +
drivers/Makefile | 1 +
drivers/acpi/Kconfig | 4 +
drivers/acpi/apei/Kconfig | 1 +
drivers/acpi/apei/apei-internal.h | 10 +-
drivers/acpi/apei/ghes.c | 1025 +------------------
drivers/acpi/apei/ghes_cper.c | 1027 ++++++++++++++++++++
drivers/ras/Kconfig | 11 +
drivers/ras/Makefile | 1 +
drivers/ras/cper-esource.c | 257 +++++
include/acpi/ghes.h | 10 +-
include/acpi/ghes_cper.h | 151 +++
include/cxl/event.h | 2 +-
15 files changed, 1559 insertions(+), 1036 deletions(-)
---
base-commit: e1914add2799225a87502051415fc5c32aeb02ae
change-id: 20260220-topics-ahmtib01-ras_ffh_arm_internal_review-bfddc7fc7cab
Best regards,
--
Ahmed Tiba <ahmed.tiba@arm.com>
^ permalink raw reply
* [PATCH v4 01/10] ACPI: APEI: GHES: share macros via a private header
From: Ahmed Tiba @ 2026-05-18 11:57 UTC (permalink / raw)
To: rafael, bp, saket.dumbre, will, xueshuai, mchehab, krzk+dt, dave,
conor+dt, vishal.l.verma, jic23, corbet, guohanjun, dave.jiang,
catalin.marinas, lenb, tony.luck, skhan, djbw, alison.schofield,
ira.weiny, robh
Cc: Ahmed Tiba, devicetree, linux-acpi, linux-doc, Dmitry.Lamerov,
linux-cxl, Michael.Zhao2, acpica-devel, linux-kernel,
linux-arm-kernel, linux-edac
In-Reply-To: <20260518-topics-ahmtib01-ras_ffh_arm_internal_review-v4-0-42698675ba61@arm.com>
Carve the CPER helper macros out of ghes.c and place them in a private
header so they can be shared with upcoming helper files. This is a
mechanical include change with no functional differences.
Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
drivers/acpi/apei/ghes.c | 94 +++++++++----------------------------------
include/acpi/ghes_cper.h | 102 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 120 insertions(+), 76 deletions(-)
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 3236a3ce79d6..4f67f46410c4 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -49,6 +49,7 @@
#include <acpi/actbl1.h>
#include <acpi/ghes.h>
+#include <acpi/ghes_cper.h>
#include <acpi/apei.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
@@ -57,40 +58,6 @@
#include "apei-internal.h"
-#define GHES_PFX "GHES: "
-
-#define GHES_ESTATUS_MAX_SIZE 65536
-#define GHES_ESOURCE_PREALLOC_MAX_SIZE 65536
-
-#define GHES_ESTATUS_POOL_MIN_ALLOC_ORDER 3
-
-/* This is just an estimation for memory pool allocation */
-#define GHES_ESTATUS_CACHE_AVG_SIZE 512
-
-#define GHES_ESTATUS_CACHES_SIZE 4
-
-#define GHES_ESTATUS_IN_CACHE_MAX_NSEC 10000000000ULL
-/* Prevent too many caches are allocated because of RCU */
-#define GHES_ESTATUS_CACHE_ALLOCED_MAX (GHES_ESTATUS_CACHES_SIZE * 3 / 2)
-
-#define GHES_ESTATUS_CACHE_LEN(estatus_len) \
- (sizeof(struct ghes_estatus_cache) + (estatus_len))
-#define GHES_ESTATUS_FROM_CACHE(estatus_cache) \
- ((struct acpi_hest_generic_status *) \
- ((struct ghes_estatus_cache *)(estatus_cache) + 1))
-
-#define GHES_ESTATUS_NODE_LEN(estatus_len) \
- (sizeof(struct ghes_estatus_node) + (estatus_len))
-#define GHES_ESTATUS_FROM_NODE(estatus_node) \
- ((struct acpi_hest_generic_status *) \
- ((struct ghes_estatus_node *)(estatus_node) + 1))
-
-#define GHES_VENDOR_ENTRY_LEN(gdata_len) \
- (sizeof(struct ghes_vendor_record_entry) + (gdata_len))
-#define GHES_GDATA_FROM_VENDOR_ENTRY(vendor_entry) \
- ((struct acpi_hest_generic_data *) \
- ((struct ghes_vendor_record_entry *)(vendor_entry) + 1))
-
/*
* NMI-like notifications vary by architecture, before the compiler can prune
* unused static functions it needs a value for these enums.
@@ -102,25 +69,6 @@
static ATOMIC_NOTIFIER_HEAD(ghes_report_chain);
-static inline bool is_hest_type_generic_v2(struct ghes *ghes)
-{
- return ghes->generic->header.type == ACPI_HEST_TYPE_GENERIC_ERROR_V2;
-}
-
-/*
- * A platform may describe one error source for the handling of synchronous
- * errors (e.g. MCE or SEA), or for handling asynchronous errors (e.g. SCI
- * or External Interrupt). On x86, the HEST notifications are always
- * asynchronous, so only SEA on ARM is delivered as a synchronous
- * notification.
- */
-static inline bool is_hest_sync_notify(struct ghes *ghes)
-{
- u8 notify_type = ghes->generic->notify.type;
-
- return notify_type == ACPI_HEST_NOTIFY_SEA;
-}
-
/*
* This driver isn't really modular, however for the time being,
* continuing to use module_param is the easiest way to remain
@@ -165,12 +113,6 @@ static DEFINE_MUTEX(ghes_devs_mutex);
*/
static DEFINE_SPINLOCK(ghes_notify_lock_irq);
-struct ghes_vendor_record_entry {
- struct work_struct work;
- int error_severity;
- char vendor_record[];
-};
-
static struct gen_pool *ghes_estatus_pool;
static struct ghes_estatus_cache __rcu *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
@@ -266,7 +208,7 @@ static void ghes_ack_error(struct acpi_hest_generic_v2 *gv2)
apei_write(val, &gv2->read_ack_register);
}
-static struct ghes *ghes_new(struct acpi_hest_generic *generic)
+struct ghes *ghes_new(struct acpi_hest_generic *generic)
{
struct ghes *ghes;
unsigned int error_block_length;
@@ -313,7 +255,7 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic)
return ERR_PTR(rc);
}
-static void ghes_fini(struct ghes *ghes)
+void ghes_fini(struct ghes *ghes)
{
kfree(ghes->estatus);
apei_unmap_generic_address(&ghes->generic->error_status_address);
@@ -363,8 +305,8 @@ static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
}
/* Check the top-level record header has an appropriate size. */
-static int __ghes_check_estatus(struct ghes *ghes,
- struct acpi_hest_generic_status *estatus)
+int __ghes_check_estatus(struct ghes *ghes,
+ struct acpi_hest_generic_status *estatus)
{
u32 len = cper_estatus_len(estatus);
u32 max_len = min(ghes->generic->error_block_length,
@@ -389,9 +331,9 @@ static int __ghes_check_estatus(struct ghes *ghes,
}
/* Read the CPER block, returning its address, and header in estatus. */
-static int __ghes_peek_estatus(struct ghes *ghes,
- struct acpi_hest_generic_status *estatus,
- u64 *buf_paddr, enum fixed_addresses fixmap_idx)
+int __ghes_peek_estatus(struct ghes *ghes,
+ struct acpi_hest_generic_status *estatus,
+ u64 *buf_paddr, enum fixed_addresses fixmap_idx)
{
struct acpi_hest_generic *g = ghes->generic;
int rc;
@@ -400,7 +342,7 @@ static int __ghes_peek_estatus(struct ghes *ghes,
if (rc) {
*buf_paddr = 0;
pr_warn_ratelimited(FW_WARN GHES_PFX
-"Failed to read error status block address for hardware error source: %d.\n",
+ "Failed to read error status block address for hardware error source: %d.\n",
g->header.source_id);
return -EIO;
}
@@ -417,9 +359,9 @@ static int __ghes_peek_estatus(struct ghes *ghes,
return 0;
}
-static int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
- u64 buf_paddr, enum fixed_addresses fixmap_idx,
- size_t buf_len)
+int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
+ u64 buf_paddr, enum fixed_addresses fixmap_idx,
+ size_t buf_len)
{
ghes_copy_tofrom_phys(estatus, buf_paddr, buf_len, 1, fixmap_idx);
if (cper_estatus_check(estatus)) {
@@ -431,9 +373,9 @@ static int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
return 0;
}
-static int ghes_read_estatus(struct ghes *ghes,
- struct acpi_hest_generic_status *estatus,
- u64 *buf_paddr, enum fixed_addresses fixmap_idx)
+int ghes_read_estatus(struct ghes *ghes,
+ struct acpi_hest_generic_status *estatus,
+ u64 *buf_paddr, enum fixed_addresses fixmap_idx)
{
int rc;
@@ -449,9 +391,9 @@ static int ghes_read_estatus(struct ghes *ghes,
cper_estatus_len(estatus));
}
-static void ghes_clear_estatus(struct ghes *ghes,
- struct acpi_hest_generic_status *estatus,
- u64 buf_paddr, enum fixed_addresses fixmap_idx)
+void ghes_clear_estatus(struct ghes *ghes,
+ struct acpi_hest_generic_status *estatus,
+ u64 buf_paddr, enum fixed_addresses fixmap_idx)
{
estatus->block_status = 0;
diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
new file mode 100644
index 000000000000..6b7632cfaf66
--- /dev/null
+++ b/include/acpi/ghes_cper.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * GHES declarations used by both the ACPI APEI GHES driver
+ * and the firmware-first CPER provider.
+ *
+ * These declarations lets GHES and other firmware-first error sources use
+ * the same helper so the non-ACPI path follows the same
+ * behavior as GHES instead of carrying a separate copy.
+ *
+ * Derived from the ACPI APEI GHES driver.
+ *
+ * Copyright 2010,2011 Intel Corp.
+ * Author: Huang Ying <ying.huang@intel.com>
+ */
+
+#ifndef ACPI_APEI_GHES_CPER_H
+#define ACPI_APEI_GHES_CPER_H
+
+#include <linux/workqueue.h>
+
+#include <acpi/ghes.h>
+
+#define GHES_PFX "GHES: "
+
+#define GHES_ESTATUS_MAX_SIZE 65536
+#define GHES_ESOURCE_PREALLOC_MAX_SIZE 65536
+
+#define GHES_ESTATUS_POOL_MIN_ALLOC_ORDER 3
+
+/* This is just an estimation for memory pool allocation */
+#define GHES_ESTATUS_CACHE_AVG_SIZE 512
+
+#define GHES_ESTATUS_CACHES_SIZE 4
+
+#define GHES_ESTATUS_IN_CACHE_MAX_NSEC 10000000000ULL
+/* Prevent too many caches are allocated because of RCU */
+#define GHES_ESTATUS_CACHE_ALLOCED_MAX (GHES_ESTATUS_CACHES_SIZE * 3 / 2)
+
+#define GHES_ESTATUS_CACHE_LEN(estatus_len) \
+ (sizeof(struct ghes_estatus_cache) + (estatus_len))
+#define GHES_ESTATUS_FROM_CACHE(estatus_cache) \
+ ((struct acpi_hest_generic_status *) \
+ ((struct ghes_estatus_cache *)(estatus_cache) + 1))
+
+#define GHES_ESTATUS_NODE_LEN(estatus_len) \
+ (sizeof(struct ghes_estatus_node) + (estatus_len))
+#define GHES_ESTATUS_FROM_NODE(estatus_node) \
+ ((struct acpi_hest_generic_status *) \
+ ((struct ghes_estatus_node *)(estatus_node) + 1))
+
+#define GHES_VENDOR_ENTRY_LEN(gdata_len) \
+ (sizeof(struct ghes_vendor_record_entry) + (gdata_len))
+#define GHES_GDATA_FROM_VENDOR_ENTRY(vendor_entry) \
+ ((struct acpi_hest_generic_data *) \
+ ((struct ghes_vendor_record_entry *)(vendor_entry) + 1))
+
+static inline bool is_hest_type_generic_v2(struct ghes *ghes)
+{
+ return ghes->generic->header.type == ACPI_HEST_TYPE_GENERIC_ERROR_V2;
+}
+
+/*
+ * A platform may describe one error source for the handling of synchronous
+ * errors (e.g. MCE or SEA), or for handling asynchronous errors (e.g. SCI
+ * or External Interrupt). On x86, the HEST notifications are always
+ * asynchronous, so only SEA on ARM is delivered as a synchronous
+ * notification.
+ */
+static inline bool is_hest_sync_notify(struct ghes *ghes)
+{
+ u8 notify_type = ghes->generic->notify.type;
+
+ return notify_type == ACPI_HEST_NOTIFY_SEA;
+}
+
+struct ghes_vendor_record_entry {
+ struct work_struct work;
+ int error_severity;
+ char vendor_record[];
+};
+
+#ifdef CONFIG_ACPI_APEI
+struct ghes *ghes_new(struct acpi_hest_generic *generic);
+void ghes_fini(struct ghes *ghes);
+
+int ghes_read_estatus(struct ghes *ghes,
+ struct acpi_hest_generic_status *estatus,
+ u64 *buf_paddr, enum fixed_addresses fixmap_idx);
+void ghes_clear_estatus(struct ghes *ghes,
+ struct acpi_hest_generic_status *estatus,
+ u64 buf_paddr, enum fixed_addresses fixmap_idx);
+int __ghes_peek_estatus(struct ghes *ghes,
+ struct acpi_hest_generic_status *estatus,
+ u64 *buf_paddr, enum fixed_addresses fixmap_idx);
+int __ghes_check_estatus(struct ghes *ghes,
+ struct acpi_hest_generic_status *estatus);
+int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
+ u64 buf_paddr, enum fixed_addresses fixmap_idx,
+ size_t buf_len);
+#endif
+
+#endif /* ACPI_APEI_GHES_CPER_H */
--
2.43.0
^ permalink raw reply related
* [PATCH v4 02/10] ACPI: APEI: GHES: move CPER read helpers
From: Ahmed Tiba @ 2026-05-18 11:57 UTC (permalink / raw)
To: rafael, bp, saket.dumbre, will, xueshuai, mchehab, krzk+dt, dave,
conor+dt, vishal.l.verma, jic23, corbet, guohanjun, dave.jiang,
catalin.marinas, lenb, tony.luck, skhan, djbw, alison.schofield,
ira.weiny, robh
Cc: Ahmed Tiba, devicetree, linux-acpi, linux-doc, Dmitry.Lamerov,
linux-cxl, Michael.Zhao2, acpica-devel, linux-kernel,
linux-arm-kernel, linux-edac
In-Reply-To: <20260518-topics-ahmtib01-ras_ffh_arm_internal_review-v4-0-42698675ba61@arm.com>
Relocate the CPER buffer mapping, peek, and clear helpers from ghes.c into
ghes_cper.c so they can be shared with other firmware-first providers.
This commit only shuffles code; behavior stays the same.
Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
drivers/acpi/apei/Makefile | 2 +-
drivers/acpi/apei/ghes.c | 166 -----------------------------------
drivers/acpi/apei/ghes_cper.c | 195 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 196 insertions(+), 167 deletions(-)
diff --git a/drivers/acpi/apei/Makefile b/drivers/acpi/apei/Makefile
index 66588d6be56f..f57f3b009d8e 100644
--- a/drivers/acpi/apei/Makefile
+++ b/drivers/acpi/apei/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_ACPI_APEI) += apei.o
-obj-$(CONFIG_ACPI_APEI_GHES) += ghes.o
+obj-$(CONFIG_ACPI_APEI_GHES) += ghes.o ghes_cper.o
# clang versions prior to 18 may blow out the stack with KASAN
ifeq ($(CONFIG_COMPILE_TEST)_$(CONFIG_CC_IS_CLANG)_$(call clang-min-version, 180000),y_y_)
KASAN_SANITIZE_ghes.o := n
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 4f67f46410c4..3f35580e8efd 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -118,26 +118,6 @@ static struct gen_pool *ghes_estatus_pool;
static struct ghes_estatus_cache __rcu *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
static atomic_t ghes_estatus_cache_alloced;
-static void __iomem *ghes_map(u64 pfn, enum fixed_addresses fixmap_idx)
-{
- phys_addr_t paddr;
- pgprot_t prot;
-
- paddr = PFN_PHYS(pfn);
- prot = arch_apei_get_mem_attribute(paddr);
- __set_fixmap(fixmap_idx, paddr, prot);
-
- return (void __iomem *) __fix_to_virt(fixmap_idx);
-}
-
-static void ghes_unmap(void __iomem *vaddr, enum fixed_addresses fixmap_idx)
-{
- int _idx = virt_to_fix((unsigned long)vaddr);
-
- WARN_ON_ONCE(fixmap_idx != _idx);
- clear_fixmap(fixmap_idx);
-}
-
int ghes_estatus_pool_init(unsigned int num_ghes)
{
unsigned long addr, len;
@@ -193,21 +173,6 @@ static void unmap_gen_v2(struct ghes *ghes)
apei_unmap_generic_address(&ghes->generic_v2->read_ack_register);
}
-static void ghes_ack_error(struct acpi_hest_generic_v2 *gv2)
-{
- int rc;
- u64 val = 0;
-
- rc = apei_read(&val, &gv2->read_ack_register);
- if (rc)
- return;
-
- val &= gv2->read_ack_preserve << gv2->read_ack_register.bit_offset;
- val |= gv2->read_ack_write << gv2->read_ack_register.bit_offset;
-
- apei_write(val, &gv2->read_ack_register);
-}
-
struct ghes *ghes_new(struct acpi_hest_generic *generic)
{
struct ghes *ghes;
@@ -280,137 +245,6 @@ static inline int ghes_severity(int severity)
}
}
-static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
- int from_phys,
- enum fixed_addresses fixmap_idx)
-{
- void __iomem *vaddr;
- u64 offset;
- u32 trunk;
-
- while (len > 0) {
- offset = paddr - (paddr & PAGE_MASK);
- vaddr = ghes_map(PHYS_PFN(paddr), fixmap_idx);
- trunk = PAGE_SIZE - offset;
- trunk = min(trunk, len);
- if (from_phys)
- memcpy_fromio(buffer, vaddr + offset, trunk);
- else
- memcpy_toio(vaddr + offset, buffer, trunk);
- len -= trunk;
- paddr += trunk;
- buffer += trunk;
- ghes_unmap(vaddr, fixmap_idx);
- }
-}
-
-/* Check the top-level record header has an appropriate size. */
-int __ghes_check_estatus(struct ghes *ghes,
- struct acpi_hest_generic_status *estatus)
-{
- u32 len = cper_estatus_len(estatus);
- u32 max_len = min(ghes->generic->error_block_length,
- ghes->estatus_length);
-
- if (len < sizeof(*estatus)) {
- pr_warn_ratelimited(FW_WARN GHES_PFX "Truncated error status block!\n");
- return -EIO;
- }
-
- if (!len || len > max_len) {
- pr_warn_ratelimited(FW_WARN GHES_PFX "Invalid error status block length!\n");
- return -EIO;
- }
-
- if (cper_estatus_check_header(estatus)) {
- pr_warn_ratelimited(FW_WARN GHES_PFX "Invalid CPER header!\n");
- return -EIO;
- }
-
- return 0;
-}
-
-/* Read the CPER block, returning its address, and header in estatus. */
-int __ghes_peek_estatus(struct ghes *ghes,
- struct acpi_hest_generic_status *estatus,
- u64 *buf_paddr, enum fixed_addresses fixmap_idx)
-{
- struct acpi_hest_generic *g = ghes->generic;
- int rc;
-
- rc = apei_read(buf_paddr, &g->error_status_address);
- if (rc) {
- *buf_paddr = 0;
- pr_warn_ratelimited(FW_WARN GHES_PFX
- "Failed to read error status block address for hardware error source: %d.\n",
- g->header.source_id);
- return -EIO;
- }
- if (!*buf_paddr)
- return -ENOENT;
-
- ghes_copy_tofrom_phys(estatus, *buf_paddr, sizeof(*estatus), 1,
- fixmap_idx);
- if (!estatus->block_status) {
- *buf_paddr = 0;
- return -ENOENT;
- }
-
- return 0;
-}
-
-int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
- u64 buf_paddr, enum fixed_addresses fixmap_idx,
- size_t buf_len)
-{
- ghes_copy_tofrom_phys(estatus, buf_paddr, buf_len, 1, fixmap_idx);
- if (cper_estatus_check(estatus)) {
- pr_warn_ratelimited(FW_WARN GHES_PFX
- "Failed to read error status block!\n");
- return -EIO;
- }
-
- return 0;
-}
-
-int ghes_read_estatus(struct ghes *ghes,
- struct acpi_hest_generic_status *estatus,
- u64 *buf_paddr, enum fixed_addresses fixmap_idx)
-{
- int rc;
-
- rc = __ghes_peek_estatus(ghes, estatus, buf_paddr, fixmap_idx);
- if (rc)
- return rc;
-
- rc = __ghes_check_estatus(ghes, estatus);
- if (rc)
- return rc;
-
- return __ghes_read_estatus(estatus, *buf_paddr, fixmap_idx,
- cper_estatus_len(estatus));
-}
-
-void ghes_clear_estatus(struct ghes *ghes,
- struct acpi_hest_generic_status *estatus,
- u64 buf_paddr, enum fixed_addresses fixmap_idx)
-{
- estatus->block_status = 0;
-
- if (!buf_paddr)
- return;
-
- ghes_copy_tofrom_phys(estatus, buf_paddr,
- sizeof(estatus->block_status), 0,
- fixmap_idx);
-
- /*
- * GHESv2 type HEST entries introduce support for error acknowledgment,
- * so only acknowledge the error if this support is present.
- */
- if (is_hest_type_generic_v2(ghes))
- ghes_ack_error(ghes->generic_v2);
-}
/**
* struct ghes_task_work - for synchronous RAS event
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
new file mode 100644
index 000000000000..7bb72fe57838
--- /dev/null
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Shared GHES helpers for firmware-first CPER error handling.
+ *
+ * This file holds the GHES helper code that is shared by the in-tree GHES
+ * driver and by other firmware-first error sources that reuse the same CPER
+ * handling flow.
+ *
+ * Derived from the ACPI APEI GHES driver.
+ *
+ * Copyright 2010,2011 Intel Corp.
+ * Author: Huang Ying <ying.huang@intel.com>
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/ratelimit.h>
+#include <linux/slab.h>
+
+#include <acpi/apei.h>
+#include <acpi/ghes_cper.h>
+
+#include <asm/fixmap.h>
+#include <asm/tlbflush.h>
+
+#include "apei-internal.h"
+
+static void __iomem *ghes_map(u64 pfn, enum fixed_addresses fixmap_idx)
+{
+ phys_addr_t paddr;
+ pgprot_t prot;
+
+ paddr = PFN_PHYS(pfn);
+ prot = arch_apei_get_mem_attribute(paddr);
+ __set_fixmap(fixmap_idx, paddr, prot);
+
+ return (void __iomem *) __fix_to_virt(fixmap_idx);
+}
+
+static void ghes_unmap(void __iomem *vaddr, enum fixed_addresses fixmap_idx)
+{
+ int _idx = virt_to_fix((unsigned long)vaddr);
+
+ WARN_ON_ONCE(fixmap_idx != _idx);
+ clear_fixmap(fixmap_idx);
+}
+
+static void ghes_ack_error(struct acpi_hest_generic_v2 *gv2)
+{
+ int rc;
+ u64 val = 0;
+
+ rc = apei_read(&val, &gv2->read_ack_register);
+ if (rc)
+ return;
+
+ val &= gv2->read_ack_preserve << gv2->read_ack_register.bit_offset;
+ val |= gv2->read_ack_write << gv2->read_ack_register.bit_offset;
+
+ apei_write(val, &gv2->read_ack_register);
+}
+
+static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
+ int from_phys,
+ enum fixed_addresses fixmap_idx)
+{
+ void __iomem *vaddr;
+ u64 offset;
+ u32 trunk;
+
+ while (len > 0) {
+ offset = paddr - (paddr & PAGE_MASK);
+ vaddr = ghes_map(PHYS_PFN(paddr), fixmap_idx);
+ trunk = PAGE_SIZE - offset;
+ trunk = min(trunk, len);
+ if (from_phys)
+ memcpy_fromio(buffer, vaddr + offset, trunk);
+ else
+ memcpy_toio(vaddr + offset, buffer, trunk);
+ len -= trunk;
+ paddr += trunk;
+ buffer += trunk;
+ ghes_unmap(vaddr, fixmap_idx);
+ }
+}
+
+/* Check the top-level record header has an appropriate size. */
+int __ghes_check_estatus(struct ghes *ghes,
+ struct acpi_hest_generic_status *estatus)
+{
+ u32 len = cper_estatus_len(estatus);
+ u32 max_len = min(ghes->generic->error_block_length,
+ ghes->estatus_length);
+
+ if (len < sizeof(*estatus)) {
+ pr_warn_ratelimited(FW_WARN GHES_PFX "Truncated error status block!\n");
+ return -EIO;
+ }
+
+ if (!len || len > max_len) {
+ pr_warn_ratelimited(FW_WARN GHES_PFX "Invalid error status block length!\n");
+ return -EIO;
+ }
+
+ if (cper_estatus_check_header(estatus)) {
+ pr_warn_ratelimited(FW_WARN GHES_PFX "Invalid CPER header!\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/* Read the CPER block, returning its address, and header in estatus. */
+int __ghes_peek_estatus(struct ghes *ghes,
+ struct acpi_hest_generic_status *estatus,
+ u64 *buf_paddr, enum fixed_addresses fixmap_idx)
+{
+ struct acpi_hest_generic *g = ghes->generic;
+ int rc;
+
+ rc = apei_read(buf_paddr, &g->error_status_address);
+ if (rc) {
+ *buf_paddr = 0;
+ pr_warn_ratelimited(FW_WARN GHES_PFX
+ "Failed to read error status block address for hardware error source: %d.\n",
+ g->header.source_id);
+ return -EIO;
+ }
+ if (!*buf_paddr)
+ return -ENOENT;
+
+ ghes_copy_tofrom_phys(estatus, *buf_paddr, sizeof(*estatus), 1,
+ fixmap_idx);
+ if (!estatus->block_status) {
+ *buf_paddr = 0;
+ return -ENOENT;
+ }
+
+ return 0;
+}
+
+int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
+ u64 buf_paddr, enum fixed_addresses fixmap_idx,
+ size_t buf_len)
+{
+ ghes_copy_tofrom_phys(estatus, buf_paddr, buf_len, 1, fixmap_idx);
+ if (cper_estatus_check(estatus)) {
+ pr_warn_ratelimited(FW_WARN GHES_PFX
+ "Failed to read error status block!\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+int ghes_read_estatus(struct ghes *ghes,
+ struct acpi_hest_generic_status *estatus,
+ u64 *buf_paddr, enum fixed_addresses fixmap_idx)
+{
+ int rc;
+
+ rc = __ghes_peek_estatus(ghes, estatus, buf_paddr, fixmap_idx);
+ if (rc)
+ return rc;
+
+ rc = __ghes_check_estatus(ghes, estatus);
+ if (rc)
+ return rc;
+
+ return __ghes_read_estatus(estatus, *buf_paddr, fixmap_idx,
+ cper_estatus_len(estatus));
+}
+
+void ghes_clear_estatus(struct ghes *ghes,
+ struct acpi_hest_generic_status *estatus,
+ u64 buf_paddr, enum fixed_addresses fixmap_idx)
+{
+ estatus->block_status = 0;
+
+ if (!buf_paddr)
+ return;
+
+ ghes_copy_tofrom_phys(estatus, buf_paddr,
+ sizeof(estatus->block_status), 0,
+ fixmap_idx);
+
+ /*
+ * GHESv2 type HEST entries introduce support for error acknowledgment,
+ * so only acknowledge the error if this support is present.
+ */
+ if (is_hest_type_generic_v2(ghes))
+ ghes_ack_error(ghes->generic_v2);
+}
--
2.43.0
^ permalink raw reply related
* [PATCH v4 03/10] ACPI: APEI: GHES: move GHESv2 ack and alloc helpers
From: Ahmed Tiba @ 2026-05-18 11:57 UTC (permalink / raw)
To: rafael, bp, saket.dumbre, will, xueshuai, mchehab, krzk+dt, dave,
conor+dt, vishal.l.verma, jic23, corbet, guohanjun, dave.jiang,
catalin.marinas, lenb, tony.luck, skhan, djbw, alison.schofield,
ira.weiny, robh
Cc: Ahmed Tiba, devicetree, linux-acpi, linux-doc, Dmitry.Lamerov,
linux-cxl, Michael.Zhao2, acpica-devel, linux-kernel,
linux-arm-kernel, linux-edac
In-Reply-To: <20260518-topics-ahmtib01-ras_ffh_arm_internal_review-v4-0-42698675ba61@arm.com>
Move the GHESv2 acknowledgment and error-source allocation helpers from
ghes.c into ghes_cper.c. This is a mechanical refactor that keeps the
logic unchanged while making the helpers reusable.
Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
drivers/acpi/apei/ghes.c | 65 -------------------------------------------
drivers/acpi/apei/ghes_cper.c | 65 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 65 insertions(+), 65 deletions(-)
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 3f35580e8efd..91638ae7e05e 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -163,71 +163,6 @@ void ghes_estatus_pool_region_free(unsigned long addr, u32 size)
}
EXPORT_SYMBOL_GPL(ghes_estatus_pool_region_free);
-static int map_gen_v2(struct ghes *ghes)
-{
- return apei_map_generic_address(&ghes->generic_v2->read_ack_register);
-}
-
-static void unmap_gen_v2(struct ghes *ghes)
-{
- apei_unmap_generic_address(&ghes->generic_v2->read_ack_register);
-}
-
-struct ghes *ghes_new(struct acpi_hest_generic *generic)
-{
- struct ghes *ghes;
- unsigned int error_block_length;
- int rc;
-
- ghes = kzalloc_obj(*ghes);
- if (!ghes)
- return ERR_PTR(-ENOMEM);
-
- ghes->generic = generic;
- if (is_hest_type_generic_v2(ghes)) {
- rc = map_gen_v2(ghes);
- if (rc)
- goto err_free;
- }
-
- rc = apei_map_generic_address(&generic->error_status_address);
- if (rc)
- goto err_unmap_read_ack_addr;
- error_block_length = generic->error_block_length;
- if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
- pr_warn(FW_WARN GHES_PFX
- "Error status block length is too long: %u for "
- "generic hardware error source: %d.\n",
- error_block_length, generic->header.source_id);
- error_block_length = GHES_ESTATUS_MAX_SIZE;
- }
- ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
- ghes->estatus_length = error_block_length;
- if (!ghes->estatus) {
- rc = -ENOMEM;
- goto err_unmap_status_addr;
- }
-
- return ghes;
-
-err_unmap_status_addr:
- apei_unmap_generic_address(&generic->error_status_address);
-err_unmap_read_ack_addr:
- if (is_hest_type_generic_v2(ghes))
- unmap_gen_v2(ghes);
-err_free:
- kfree(ghes);
- return ERR_PTR(rc);
-}
-
-void ghes_fini(struct ghes *ghes)
-{
- kfree(ghes->estatus);
- apei_unmap_generic_address(&ghes->generic->error_status_address);
- if (is_hest_type_generic_v2(ghes))
- unmap_gen_v2(ghes);
-}
-
static inline int ghes_severity(int severity)
{
switch (severity) {
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
index 7bb72fe57838..8080e0f76dac 100644
--- a/drivers/acpi/apei/ghes_cper.c
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -62,6 +62,71 @@ static void ghes_ack_error(struct acpi_hest_generic_v2 *gv2)
apei_write(val, &gv2->read_ack_register);
}
+static int map_gen_v2(struct ghes *ghes)
+{
+ return apei_map_generic_address(&ghes->generic_v2->read_ack_register);
+}
+
+static void unmap_gen_v2(struct ghes *ghes)
+{
+ apei_unmap_generic_address(&ghes->generic_v2->read_ack_register);
+}
+
+struct ghes *ghes_new(struct acpi_hest_generic *generic)
+{
+ struct ghes *ghes;
+ unsigned int error_block_length;
+ int rc;
+
+ ghes = kzalloc_obj(*ghes);
+ if (!ghes)
+ return ERR_PTR(-ENOMEM);
+
+ ghes->generic = generic;
+ if (is_hest_type_generic_v2(ghes)) {
+ rc = map_gen_v2(ghes);
+ if (rc)
+ goto err_free;
+ }
+
+ rc = apei_map_generic_address(&generic->error_status_address);
+ if (rc)
+ goto err_unmap_read_ack_addr;
+ error_block_length = generic->error_block_length;
+ if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
+ pr_warn(FW_WARN GHES_PFX
+ "Error status block length is too long: %u for "
+ "generic hardware error source: %d.\n",
+ error_block_length, generic->header.source_id);
+ error_block_length = GHES_ESTATUS_MAX_SIZE;
+ }
+ ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
+ ghes->estatus_length = error_block_length;
+ if (!ghes->estatus) {
+ rc = -ENOMEM;
+ goto err_unmap_status_addr;
+ }
+
+ return ghes;
+
+err_unmap_status_addr:
+ apei_unmap_generic_address(&generic->error_status_address);
+err_unmap_read_ack_addr:
+ if (is_hest_type_generic_v2(ghes))
+ unmap_gen_v2(ghes);
+err_free:
+ kfree(ghes);
+ return ERR_PTR(rc);
+}
+
+void ghes_fini(struct ghes *ghes)
+{
+ kfree(ghes->estatus);
+ apei_unmap_generic_address(&ghes->generic->error_status_address);
+ if (is_hest_type_generic_v2(ghes))
+ unmap_gen_v2(ghes);
+}
+
static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
int from_phys,
enum fixed_addresses fixmap_idx)
--
2.43.0
^ permalink raw reply related
* [PATCH v4 04/10] ACPI: APEI: GHES: move estatus cache helpers
From: Ahmed Tiba @ 2026-05-18 11:57 UTC (permalink / raw)
To: rafael, bp, saket.dumbre, will, xueshuai, mchehab, krzk+dt, dave,
conor+dt, vishal.l.verma, jic23, corbet, guohanjun, dave.jiang,
catalin.marinas, lenb, tony.luck, skhan, djbw, alison.schofield,
ira.weiny, robh
Cc: Ahmed Tiba, devicetree, linux-acpi, linux-doc, Dmitry.Lamerov,
linux-cxl, Michael.Zhao2, acpica-devel, linux-kernel,
linux-arm-kernel, linux-edac
In-Reply-To: <20260518-topics-ahmtib01-ras_ffh_arm_internal_review-v4-0-42698675ba61@arm.com>
Relocate the estatus cache allocation and lookup helpers from ghes.c into
ghes_cper.c. This code move keeps the logic intact while making the cache
implementation available to forthcoming users.
Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
drivers/acpi/apei/ghes.c | 138 +----------------------------------------
drivers/acpi/apei/ghes_cper.c | 140 ++++++++++++++++++++++++++++++++++++++++++
include/acpi/ghes_cper.h | 6 ++
3 files changed, 147 insertions(+), 137 deletions(-)
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 91638ae7e05e..adab7404310e 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -113,10 +113,7 @@ static DEFINE_MUTEX(ghes_devs_mutex);
*/
static DEFINE_SPINLOCK(ghes_notify_lock_irq);
-static struct gen_pool *ghes_estatus_pool;
-
-static struct ghes_estatus_cache __rcu *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
-static atomic_t ghes_estatus_cache_alloced;
+struct gen_pool *ghes_estatus_pool;
int ghes_estatus_pool_init(unsigned int num_ghes)
{
@@ -733,139 +730,6 @@ static int ghes_print_estatus(const char *pfx,
return 0;
}
-/*
- * GHES error status reporting throttle, to report more kinds of
- * errors, instead of just most frequently occurred errors.
- */
-static int ghes_estatus_cached(struct acpi_hest_generic_status *estatus)
-{
- u32 len;
- int i, cached = 0;
- unsigned long long now;
- struct ghes_estatus_cache *cache;
- struct acpi_hest_generic_status *cache_estatus;
-
- len = cper_estatus_len(estatus);
- rcu_read_lock();
- for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
- cache = rcu_dereference(ghes_estatus_caches[i]);
- if (cache == NULL)
- continue;
- if (len != cache->estatus_len)
- continue;
- cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
- if (memcmp(estatus, cache_estatus, len))
- continue;
- atomic_inc(&cache->count);
- now = sched_clock();
- if (now - cache->time_in < GHES_ESTATUS_IN_CACHE_MAX_NSEC)
- cached = 1;
- break;
- }
- rcu_read_unlock();
- return cached;
-}
-
-static struct ghes_estatus_cache *ghes_estatus_cache_alloc(
- struct acpi_hest_generic *generic,
- struct acpi_hest_generic_status *estatus)
-{
- int alloced;
- u32 len, cache_len;
- struct ghes_estatus_cache *cache;
- struct acpi_hest_generic_status *cache_estatus;
-
- alloced = atomic_add_return(1, &ghes_estatus_cache_alloced);
- if (alloced > GHES_ESTATUS_CACHE_ALLOCED_MAX) {
- atomic_dec(&ghes_estatus_cache_alloced);
- return NULL;
- }
- len = cper_estatus_len(estatus);
- cache_len = GHES_ESTATUS_CACHE_LEN(len);
- cache = (void *)gen_pool_alloc(ghes_estatus_pool, cache_len);
- if (!cache) {
- atomic_dec(&ghes_estatus_cache_alloced);
- return NULL;
- }
- cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
- memcpy(cache_estatus, estatus, len);
- cache->estatus_len = len;
- atomic_set(&cache->count, 0);
- cache->generic = generic;
- cache->time_in = sched_clock();
- return cache;
-}
-
-static void ghes_estatus_cache_rcu_free(struct rcu_head *head)
-{
- struct ghes_estatus_cache *cache;
- u32 len;
-
- cache = container_of(head, struct ghes_estatus_cache, rcu);
- len = cper_estatus_len(GHES_ESTATUS_FROM_CACHE(cache));
- len = GHES_ESTATUS_CACHE_LEN(len);
- gen_pool_free(ghes_estatus_pool, (unsigned long)cache, len);
- atomic_dec(&ghes_estatus_cache_alloced);
-}
-
-static void
-ghes_estatus_cache_add(struct acpi_hest_generic *generic,
- struct acpi_hest_generic_status *estatus)
-{
- unsigned long long now, duration, period, max_period = 0;
- struct ghes_estatus_cache *cache, *new_cache;
- struct ghes_estatus_cache __rcu *victim;
- int i, slot = -1, count;
-
- new_cache = ghes_estatus_cache_alloc(generic, estatus);
- if (!new_cache)
- return;
-
- rcu_read_lock();
- now = sched_clock();
- for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
- cache = rcu_dereference(ghes_estatus_caches[i]);
- if (cache == NULL) {
- slot = i;
- break;
- }
- duration = now - cache->time_in;
- if (duration >= GHES_ESTATUS_IN_CACHE_MAX_NSEC) {
- slot = i;
- break;
- }
- count = atomic_read(&cache->count);
- period = duration;
- do_div(period, (count + 1));
- if (period > max_period) {
- max_period = period;
- slot = i;
- }
- }
- rcu_read_unlock();
-
- if (slot != -1) {
- /*
- * Use release semantics to ensure that ghes_estatus_cached()
- * running on another CPU will see the updated cache fields if
- * it can see the new value of the pointer.
- */
- victim = xchg_release(&ghes_estatus_caches[slot],
- RCU_INITIALIZER(new_cache));
-
- /*
- * At this point, victim may point to a cached item different
- * from the one based on which we selected the slot. Instead of
- * going to the loop again to pick another slot, let's just
- * drop the other item anyway: this may cause a false cache
- * miss later on, but that won't cause any problems.
- */
- if (victim)
- call_rcu(&unrcu_pointer(victim)->rcu,
- ghes_estatus_cache_rcu_free);
- }
-}
-
static void __ghes_panic(struct ghes *ghes,
struct acpi_hest_generic_status *estatus,
u64 buf_paddr, enum fixed_addresses fixmap_idx)
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
index 8080e0f76dac..0a117f478afb 100644
--- a/drivers/acpi/apei/ghes_cper.c
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -13,10 +13,14 @@
*/
#include <linux/err.h>
+#include <linux/genalloc.h>
#include <linux/io.h>
#include <linux/kernel.h>
+#include <linux/math64.h>
#include <linux/mm.h>
#include <linux/ratelimit.h>
+#include <linux/rcupdate.h>
+#include <linux/sched/clock.h>
#include <linux/slab.h>
#include <acpi/apei.h>
@@ -27,6 +31,9 @@
#include "apei-internal.h"
+static struct ghes_estatus_cache __rcu *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
+static atomic_t ghes_estatus_cache_alloced;
+
static void __iomem *ghes_map(u64 pfn, enum fixed_addresses fixmap_idx)
{
phys_addr_t paddr;
@@ -258,3 +265,136 @@ void ghes_clear_estatus(struct ghes *ghes,
if (is_hest_type_generic_v2(ghes))
ghes_ack_error(ghes->generic_v2);
}
+
+/*
+ * GHES error status reporting throttle, to report more kinds of
+ * errors, instead of just most frequently occurred errors.
+ */
+int ghes_estatus_cached(struct acpi_hest_generic_status *estatus)
+{
+ u32 len;
+ int i, cached = 0;
+ unsigned long long now;
+ struct ghes_estatus_cache *cache;
+ struct acpi_hest_generic_status *cache_estatus;
+
+ len = cper_estatus_len(estatus);
+ rcu_read_lock();
+ for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
+ cache = rcu_dereference(ghes_estatus_caches[i]);
+ if (cache == NULL)
+ continue;
+ if (len != cache->estatus_len)
+ continue;
+ cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
+ if (memcmp(estatus, cache_estatus, len))
+ continue;
+ atomic_inc(&cache->count);
+ now = sched_clock();
+ if (now - cache->time_in < GHES_ESTATUS_IN_CACHE_MAX_NSEC)
+ cached = 1;
+ break;
+ }
+ rcu_read_unlock();
+ return cached;
+}
+
+static struct ghes_estatus_cache *ghes_estatus_cache_alloc(
+ struct acpi_hest_generic *generic,
+ struct acpi_hest_generic_status *estatus)
+{
+ int alloced;
+ u32 len, cache_len;
+ struct ghes_estatus_cache *cache;
+ struct acpi_hest_generic_status *cache_estatus;
+
+ alloced = atomic_add_return(1, &ghes_estatus_cache_alloced);
+ if (alloced > GHES_ESTATUS_CACHE_ALLOCED_MAX) {
+ atomic_dec(&ghes_estatus_cache_alloced);
+ return NULL;
+ }
+ len = cper_estatus_len(estatus);
+ cache_len = GHES_ESTATUS_CACHE_LEN(len);
+ cache = (void *)gen_pool_alloc(ghes_estatus_pool, cache_len);
+ if (cache == NULL) {
+ atomic_dec(&ghes_estatus_cache_alloced);
+ return NULL;
+ }
+ cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
+ memcpy(cache_estatus, estatus, len);
+ cache->estatus_len = len;
+ atomic_set(&cache->count, 0);
+ cache->generic = generic;
+ cache->time_in = sched_clock();
+ return cache;
+}
+
+static void ghes_estatus_cache_rcu_free(struct rcu_head *head)
+{
+ struct ghes_estatus_cache *cache;
+ u32 len;
+
+ cache = container_of(head, struct ghes_estatus_cache, rcu);
+ len = cper_estatus_len(GHES_ESTATUS_FROM_CACHE(cache));
+ len = GHES_ESTATUS_CACHE_LEN(len);
+ gen_pool_free(ghes_estatus_pool, (unsigned long)cache, len);
+ atomic_dec(&ghes_estatus_cache_alloced);
+}
+
+void
+ghes_estatus_cache_add(struct acpi_hest_generic *generic,
+ struct acpi_hest_generic_status *estatus)
+{
+ unsigned long long now, duration, period, max_period = 0;
+ struct ghes_estatus_cache *cache, *new_cache;
+ struct ghes_estatus_cache __rcu *victim;
+ int i, slot = -1, count;
+
+ new_cache = ghes_estatus_cache_alloc(generic, estatus);
+ if (!new_cache)
+ return;
+
+ rcu_read_lock();
+ now = sched_clock();
+ for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
+ cache = rcu_dereference(ghes_estatus_caches[i]);
+ if (cache == NULL) {
+ slot = i;
+ break;
+ }
+ duration = now - cache->time_in;
+ if (duration >= GHES_ESTATUS_IN_CACHE_MAX_NSEC) {
+ slot = i;
+ break;
+ }
+ count = atomic_read(&cache->count);
+ period = duration;
+ do_div(period, (count + 1));
+ if (period > max_period) {
+ max_period = period;
+ slot = i;
+ }
+ }
+ rcu_read_unlock();
+
+ if (slot != -1) {
+ /*
+ * Use release semantics to ensure that ghes_estatus_cached()
+ * running on another CPU will see the updated cache fields if
+ * it can see the new value of the pointer.
+ */
+ victim = xchg_release(&ghes_estatus_caches[slot],
+ RCU_INITIALIZER(new_cache));
+
+ /*
+ * At this point, victim may point to a cached item different
+ * from the one based on which we selected the slot. Instead of
+ * going to the loop again to pick another slot, let's just
+ * drop the other item anyway: this may cause a false cache
+ * miss later on, but that won't cause any problems.
+ */
+ if (victim)
+ call_rcu(&unrcu_pointer(victim)->rcu,
+ ghes_estatus_cache_rcu_free);
+ }
+}
diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
index 6b7632cfaf66..1b5dbeca9bb6 100644
--- a/include/acpi/ghes_cper.h
+++ b/include/acpi/ghes_cper.h
@@ -16,6 +16,7 @@
#ifndef ACPI_APEI_GHES_CPER_H
#define ACPI_APEI_GHES_CPER_H
+#include <linux/atomic.h>
#include <linux/workqueue.h>
#include <acpi/ghes.h>
@@ -54,6 +55,8 @@
((struct acpi_hest_generic_data *) \
((struct ghes_vendor_record_entry *)(vendor_entry) + 1))
+extern struct gen_pool *ghes_estatus_pool;
+
static inline bool is_hest_type_generic_v2(struct ghes *ghes)
{
return ghes->generic->header.type == ACPI_HEST_TYPE_GENERIC_ERROR_V2;
@@ -98,5 +101,8 @@ int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
u64 buf_paddr, enum fixed_addresses fixmap_idx,
size_t buf_len);
#endif
+int ghes_estatus_cached(struct acpi_hest_generic_status *estatus);
+void ghes_estatus_cache_add(struct acpi_hest_generic *generic,
+ struct acpi_hest_generic_status *estatus);
#endif /* ACPI_APEI_GHES_CPER_H */
--
2.43.0
^ permalink raw reply related
* [PATCH v4 05/10] ACPI: APEI: GHES: move vendor record helpers
From: Ahmed Tiba @ 2026-05-18 11:57 UTC (permalink / raw)
To: rafael, bp, saket.dumbre, will, xueshuai, mchehab, krzk+dt, dave,
conor+dt, vishal.l.verma, jic23, corbet, guohanjun, dave.jiang,
catalin.marinas, lenb, tony.luck, skhan, djbw, alison.schofield,
ira.weiny, robh
Cc: Ahmed Tiba, devicetree, linux-acpi, linux-doc, Dmitry.Lamerov,
linux-cxl, Michael.Zhao2, acpica-devel, linux-kernel,
linux-arm-kernel, linux-edac
In-Reply-To: <20260518-topics-ahmtib01-ras_ffh_arm_internal_review-v4-0-42698675ba61@arm.com>
Shift the vendor record workqueue helpers into ghes_cper.c so both GHES
and future DT-based providers can use the same implementation. The change
is mechanical and keeps the notifier behavior identical.
Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
drivers/acpi/apei/ghes.c | 86 +++++++++----------------------------------
drivers/acpi/apei/ghes_cper.c | 55 +++++++++++++++++++++++++++
include/acpi/ghes_cper.h | 2 +
3 files changed, 75 insertions(+), 68 deletions(-)
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index adab7404310e..81ac51632f21 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -383,74 +383,6 @@ static void ghes_handle_aer(struct acpi_hest_generic_data *gdata)
#endif
}
-static BLOCKING_NOTIFIER_HEAD(vendor_record_notify_list);
-
-int ghes_register_vendor_record_notifier(struct notifier_block *nb)
-{
- return blocking_notifier_chain_register(&vendor_record_notify_list, nb);
-}
-EXPORT_SYMBOL_GPL(ghes_register_vendor_record_notifier);
-
-void ghes_unregister_vendor_record_notifier(struct notifier_block *nb)
-{
- blocking_notifier_chain_unregister(&vendor_record_notify_list, nb);
-}
-EXPORT_SYMBOL_GPL(ghes_unregister_vendor_record_notifier);
-
-static void ghes_vendor_record_notifier_destroy(void *nb)
-{
- ghes_unregister_vendor_record_notifier(nb);
-}
-
-int devm_ghes_register_vendor_record_notifier(struct device *dev,
- struct notifier_block *nb)
-{
- int ret;
-
- ret = ghes_register_vendor_record_notifier(nb);
- if (ret)
- return ret;
-
- return devm_add_action_or_reset(dev, ghes_vendor_record_notifier_destroy, nb);
-}
-EXPORT_SYMBOL_GPL(devm_ghes_register_vendor_record_notifier);
-
-static void ghes_vendor_record_work_func(struct work_struct *work)
-{
- struct ghes_vendor_record_entry *entry;
- struct acpi_hest_generic_data *gdata;
- u32 len;
-
- entry = container_of(work, struct ghes_vendor_record_entry, work);
- gdata = GHES_GDATA_FROM_VENDOR_ENTRY(entry);
-
- blocking_notifier_call_chain(&vendor_record_notify_list,
- entry->error_severity, gdata);
-
- len = GHES_VENDOR_ENTRY_LEN(acpi_hest_get_record_size(gdata));
- gen_pool_free(ghes_estatus_pool, (unsigned long)entry, len);
-}
-
-static void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
- int sev)
-{
- struct acpi_hest_generic_data *copied_gdata;
- struct ghes_vendor_record_entry *entry;
- u32 len;
-
- len = GHES_VENDOR_ENTRY_LEN(acpi_hest_get_record_size(gdata));
- entry = (void *)gen_pool_alloc(ghes_estatus_pool, len);
- if (!entry)
- return;
-
- copied_gdata = GHES_GDATA_FROM_VENDOR_ENTRY(entry);
- memcpy(copied_gdata, gdata, acpi_hest_get_record_size(gdata));
- entry->error_severity = sev;
-
- INIT_WORK(&entry->work, ghes_vendor_record_work_func);
- schedule_work(&entry->work);
-}
-
/* Room for 8 entries */
#define CXL_CPER_PROT_ERR_FIFO_DEPTH 8
static DEFINE_KFIFO(cxl_cper_prot_err_fifo, struct cxl_cper_prot_err_work_data,
@@ -514,6 +446,24 @@ int cxl_cper_prot_err_kfifo_get(struct cxl_cper_prot_err_work_data *wd)
}
EXPORT_SYMBOL_NS_GPL(cxl_cper_prot_err_kfifo_get, "CXL");
+static void ghes_vendor_record_notifier_destroy(void *nb)
+{
+ ghes_unregister_vendor_record_notifier(nb);
+}
+
+int devm_ghes_register_vendor_record_notifier(struct device *dev,
+ struct notifier_block *nb)
+{
+ int ret;
+
+ ret = ghes_register_vendor_record_notifier(nb);
+ if (ret)
+ return ret;
+
+ return devm_add_action_or_reset(dev, ghes_vendor_record_notifier_destroy, nb);
+}
+EXPORT_SYMBOL_GPL(devm_ghes_register_vendor_record_notifier);
+
/* Room for 8 entries for each of the 4 event log queues */
#define CXL_CPER_FIFO_DEPTH 32
DEFINE_KFIFO(cxl_cper_fifo, struct cxl_cper_work_data, CXL_CPER_FIFO_DEPTH);
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
index 0a117f478afb..131980d36064 100644
--- a/drivers/acpi/apei/ghes_cper.c
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -14,12 +14,17 @@
#include <linux/err.h>
#include <linux/genalloc.h>
+#include <linux/irq_work.h>
#include <linux/io.h>
#include <linux/kernel.h>
+#include <linux/list.h>
#include <linux/math64.h>
#include <linux/mm.h>
+#include <linux/notifier.h>
+#include <linux/llist.h>
#include <linux/ratelimit.h>
#include <linux/rcupdate.h>
+#include <linux/rculist.h>
#include <linux/sched/clock.h>
#include <linux/slab.h>
@@ -266,6 +271,56 @@ void ghes_clear_estatus(struct ghes *ghes,
ghes_ack_error(ghes->generic_v2);
}
+static BLOCKING_NOTIFIER_HEAD(vendor_record_notify_list);
+
+int ghes_register_vendor_record_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&vendor_record_notify_list, nb);
+}
+EXPORT_SYMBOL_GPL(ghes_register_vendor_record_notifier);
+
+void ghes_unregister_vendor_record_notifier(struct notifier_block *nb)
+{
+ blocking_notifier_chain_unregister(&vendor_record_notify_list, nb);
+}
+EXPORT_SYMBOL_GPL(ghes_unregister_vendor_record_notifier);
+
+static void ghes_vendor_record_work_func(struct work_struct *work)
+{
+ struct ghes_vendor_record_entry *entry;
+ struct acpi_hest_generic_data *gdata;
+ u32 len;
+
+ entry = container_of(work, struct ghes_vendor_record_entry, work);
+ gdata = GHES_GDATA_FROM_VENDOR_ENTRY(entry);
+
+ blocking_notifier_call_chain(&vendor_record_notify_list,
+ entry->error_severity, gdata);
+
+ len = GHES_VENDOR_ENTRY_LEN(acpi_hest_get_record_size(gdata));
+ gen_pool_free(ghes_estatus_pool, (unsigned long)entry, len);
+}
+
+void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
+ int sev)
+{
+ struct acpi_hest_generic_data *copied_gdata;
+ struct ghes_vendor_record_entry *entry;
+ u32 len;
+
+ len = GHES_VENDOR_ENTRY_LEN(acpi_hest_get_record_size(gdata));
+ entry = (void *)gen_pool_alloc(ghes_estatus_pool, len);
+ if (!entry)
+ return;
+
+ copied_gdata = GHES_GDATA_FROM_VENDOR_ENTRY(entry);
+ memcpy(copied_gdata, gdata, acpi_hest_get_record_size(gdata));
+ entry->error_severity = sev;
+
+ INIT_WORK(&entry->work, ghes_vendor_record_work_func);
+ schedule_work(&entry->work);
+}
+
/*
* GHES error status reporting throttle, to report more kinds of
* errors, instead of just most frequently occurred errors.
diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
index 1b5dbeca9bb6..51725f25c516 100644
--- a/include/acpi/ghes_cper.h
+++ b/include/acpi/ghes_cper.h
@@ -104,5 +104,7 @@ int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
int ghes_estatus_cached(struct acpi_hest_generic_status *estatus);
void ghes_estatus_cache_add(struct acpi_hest_generic *generic,
struct acpi_hest_generic_status *estatus);
+void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
+ int sev);
#endif /* ACPI_APEI_GHES_CPER_H */
--
2.43.0
^ permalink raw reply related
* [PATCH v4 06/10] ACPI: APEI: GHES: move CXL CPER helpers
From: Ahmed Tiba @ 2026-05-18 11:57 UTC (permalink / raw)
To: rafael, bp, saket.dumbre, will, xueshuai, mchehab, krzk+dt, dave,
conor+dt, vishal.l.verma, jic23, corbet, guohanjun, dave.jiang,
catalin.marinas, lenb, tony.luck, skhan, djbw, alison.schofield,
ira.weiny, robh
Cc: Ahmed Tiba, devicetree, linux-acpi, linux-doc, Dmitry.Lamerov,
linux-cxl, Michael.Zhao2, acpica-devel, linux-kernel,
linux-arm-kernel, linux-edac
In-Reply-To: <20260518-topics-ahmtib01-ras_ffh_arm_internal_review-v4-0-42698675ba61@arm.com>
Move the CXL CPER handling paths out of ghes.c and into ghes_cper.c so the
helpers can be reused. The code is moved as-is, with the public
prototypes updated so GHES keeps calling into the new translation unit.
Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
drivers/acpi/apei/ghes.c | 132 -----------------------------------------
drivers/acpi/apei/ghes_cper.c | 134 ++++++++++++++++++++++++++++++++++++++++++
include/acpi/ghes_cper.h | 11 ++++
3 files changed, 145 insertions(+), 132 deletions(-)
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 81ac51632f21..85be2ebf4d3e 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -383,69 +383,6 @@ static void ghes_handle_aer(struct acpi_hest_generic_data *gdata)
#endif
}
-/* Room for 8 entries */
-#define CXL_CPER_PROT_ERR_FIFO_DEPTH 8
-static DEFINE_KFIFO(cxl_cper_prot_err_fifo, struct cxl_cper_prot_err_work_data,
- CXL_CPER_PROT_ERR_FIFO_DEPTH);
-
-/* Synchronize schedule_work() with cxl_cper_prot_err_work changes */
-static DEFINE_SPINLOCK(cxl_cper_prot_err_work_lock);
-struct work_struct *cxl_cper_prot_err_work;
-
-static void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err,
- int severity)
-{
-#ifdef CONFIG_ACPI_APEI_PCIEAER
- struct cxl_cper_prot_err_work_data wd;
-
- if (cxl_cper_sec_prot_err_valid(prot_err))
- return;
-
- guard(spinlock_irqsave)(&cxl_cper_prot_err_work_lock);
-
- if (!cxl_cper_prot_err_work)
- return;
-
- if (cxl_cper_setup_prot_err_work_data(&wd, prot_err, severity))
- return;
-
- if (!kfifo_put(&cxl_cper_prot_err_fifo, wd)) {
- pr_err_ratelimited("CXL CPER kfifo overflow\n");
- return;
- }
-
- schedule_work(cxl_cper_prot_err_work);
-#endif
-}
-
-int cxl_cper_register_prot_err_work(struct work_struct *work)
-{
- if (cxl_cper_prot_err_work)
- return -EINVAL;
-
- guard(spinlock)(&cxl_cper_prot_err_work_lock);
- cxl_cper_prot_err_work = work;
- return 0;
-}
-EXPORT_SYMBOL_NS_GPL(cxl_cper_register_prot_err_work, "CXL");
-
-int cxl_cper_unregister_prot_err_work(struct work_struct *work)
-{
- if (cxl_cper_prot_err_work != work)
- return -EINVAL;
-
- guard(spinlock)(&cxl_cper_prot_err_work_lock);
- cxl_cper_prot_err_work = NULL;
- return 0;
-}
-EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_prot_err_work, "CXL");
-
-int cxl_cper_prot_err_kfifo_get(struct cxl_cper_prot_err_work_data *wd)
-{
- return kfifo_get(&cxl_cper_prot_err_fifo, wd);
-}
-EXPORT_SYMBOL_NS_GPL(cxl_cper_prot_err_kfifo_get, "CXL");
-
static void ghes_vendor_record_notifier_destroy(void *nb)
{
ghes_unregister_vendor_record_notifier(nb);
@@ -464,75 +401,6 @@ int devm_ghes_register_vendor_record_notifier(struct device *dev,
}
EXPORT_SYMBOL_GPL(devm_ghes_register_vendor_record_notifier);
-/* Room for 8 entries for each of the 4 event log queues */
-#define CXL_CPER_FIFO_DEPTH 32
-DEFINE_KFIFO(cxl_cper_fifo, struct cxl_cper_work_data, CXL_CPER_FIFO_DEPTH);
-
-/* Synchronize schedule_work() with cxl_cper_work changes */
-static DEFINE_SPINLOCK(cxl_cper_work_lock);
-struct work_struct *cxl_cper_work;
-
-static void cxl_cper_post_event(enum cxl_event_type event_type,
- struct cxl_cper_event_rec *rec)
-{
- struct cxl_cper_work_data wd;
-
- if (rec->hdr.length <= sizeof(rec->hdr) ||
- rec->hdr.length > sizeof(*rec)) {
- pr_err(FW_WARN "CXL CPER Invalid section length (%u)\n",
- rec->hdr.length);
- return;
- }
-
- if (!(rec->hdr.validation_bits & CPER_CXL_COMP_EVENT_LOG_VALID)) {
- pr_err(FW_WARN "CXL CPER invalid event\n");
- return;
- }
-
- guard(spinlock_irqsave)(&cxl_cper_work_lock);
-
- if (!cxl_cper_work)
- return;
-
- wd.event_type = event_type;
- memcpy(&wd.rec, rec, sizeof(wd.rec));
-
- if (!kfifo_put(&cxl_cper_fifo, wd)) {
- pr_err_ratelimited("CXL CPER kfifo overflow\n");
- return;
- }
-
- schedule_work(cxl_cper_work);
-}
-
-int cxl_cper_register_work(struct work_struct *work)
-{
- if (cxl_cper_work)
- return -EINVAL;
-
- guard(spinlock)(&cxl_cper_work_lock);
- cxl_cper_work = work;
- return 0;
-}
-EXPORT_SYMBOL_NS_GPL(cxl_cper_register_work, "CXL");
-
-int cxl_cper_unregister_work(struct work_struct *work)
-{
- if (cxl_cper_work != work)
- return -EINVAL;
-
- guard(spinlock)(&cxl_cper_work_lock);
- cxl_cper_work = NULL;
- return 0;
-}
-EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_work, "CXL");
-
-int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd)
-{
- return kfifo_get(&cxl_cper_fifo, wd);
-}
-EXPORT_SYMBOL_NS_GPL(cxl_cper_kfifo_get, "CXL");
-
static void ghes_log_hwerr(int sev, guid_t *sec_type)
{
if (sev != CPER_SEV_RECOVERABLE)
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
index 131980d36064..d7a666a163c3 100644
--- a/drivers/acpi/apei/ghes_cper.c
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -12,10 +12,12 @@
* Author: Huang Ying <ying.huang@intel.com>
*/
+#include <linux/aer.h>
#include <linux/err.h>
#include <linux/genalloc.h>
#include <linux/irq_work.h>
#include <linux/io.h>
+#include <linux/kfifo.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/math64.h>
@@ -321,6 +323,138 @@ void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
schedule_work(&entry->work);
}
+/* Room for 8 entries */
+#define CXL_CPER_PROT_ERR_FIFO_DEPTH 8
+static DEFINE_KFIFO(cxl_cper_prot_err_fifo, struct cxl_cper_prot_err_work_data,
+ CXL_CPER_PROT_ERR_FIFO_DEPTH);
+
+/* Synchronize schedule_work() with cxl_cper_prot_err_work changes */
+static DEFINE_SPINLOCK(cxl_cper_prot_err_work_lock);
+struct work_struct *cxl_cper_prot_err_work;
+
+void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err,
+ int severity)
+{
+#ifdef CONFIG_ACPI_APEI_PCIEAER
+ struct cxl_cper_prot_err_work_data wd;
+
+ if (cxl_cper_sec_prot_err_valid(prot_err))
+ return;
+
+ guard(spinlock_irqsave)(&cxl_cper_prot_err_work_lock);
+
+ if (!cxl_cper_prot_err_work)
+ return;
+
+ if (cxl_cper_setup_prot_err_work_data(&wd, prot_err, severity))
+ return;
+
+ if (!kfifo_put(&cxl_cper_prot_err_fifo, wd)) {
+ pr_err_ratelimited("CXL CPER kfifo overflow\n");
+ return;
+ }
+
+ schedule_work(cxl_cper_prot_err_work);
+#endif
+}
+
+int cxl_cper_register_prot_err_work(struct work_struct *work)
+{
+ if (cxl_cper_prot_err_work)
+ return -EINVAL;
+
+ guard(spinlock)(&cxl_cper_prot_err_work_lock);
+ cxl_cper_prot_err_work = work;
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_cper_register_prot_err_work, "CXL");
+
+int cxl_cper_unregister_prot_err_work(struct work_struct *work)
+{
+ if (cxl_cper_prot_err_work != work)
+ return -EINVAL;
+
+ guard(spinlock)(&cxl_cper_prot_err_work_lock);
+ cxl_cper_prot_err_work = NULL;
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_prot_err_work, "CXL");
+
+int cxl_cper_prot_err_kfifo_get(struct cxl_cper_prot_err_work_data *wd)
+{
+ return kfifo_get(&cxl_cper_prot_err_fifo, wd);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_cper_prot_err_kfifo_get, "CXL");
+
+/* Room for 8 entries for each of the 4 event log queues */
+#define CXL_CPER_FIFO_DEPTH 32
+static DEFINE_KFIFO(cxl_cper_fifo, struct cxl_cper_work_data, CXL_CPER_FIFO_DEPTH);
+
+/* Synchronize schedule_work() with cxl_cper_work changes */
+static DEFINE_SPINLOCK(cxl_cper_work_lock);
+struct work_struct *cxl_cper_work;
+
+void cxl_cper_post_event(enum cxl_event_type event_type,
+ struct cxl_cper_event_rec *rec)
+{
+ struct cxl_cper_work_data wd;
+
+ if (rec->hdr.length <= sizeof(rec->hdr) ||
+ rec->hdr.length > sizeof(*rec)) {
+ pr_err(FW_WARN "CXL CPER Invalid section length (%u)\n",
+ rec->hdr.length);
+ return;
+ }
+
+ if (!(rec->hdr.validation_bits & CPER_CXL_COMP_EVENT_LOG_VALID)) {
+ pr_err(FW_WARN "CXL CPER invalid event\n");
+ return;
+ }
+
+ guard(spinlock_irqsave)(&cxl_cper_work_lock);
+
+ if (!cxl_cper_work)
+ return;
+
+ wd.event_type = event_type;
+ memcpy(&wd.rec, rec, sizeof(wd.rec));
+
+ if (!kfifo_put(&cxl_cper_fifo, wd)) {
+ pr_err_ratelimited("CXL CPER kfifo overflow\n");
+ return;
+ }
+
+ schedule_work(cxl_cper_work);
+}
+
+int cxl_cper_register_work(struct work_struct *work)
+{
+ if (cxl_cper_work)
+ return -EINVAL;
+
+ guard(spinlock)(&cxl_cper_work_lock);
+ cxl_cper_work = work;
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_cper_register_work, "CXL");
+
+int cxl_cper_unregister_work(struct work_struct *work)
+{
+ if (cxl_cper_work != work)
+ return -EINVAL;
+
+ guard(spinlock)(&cxl_cper_work_lock);
+ cxl_cper_work = NULL;
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_work, "CXL");
+
+int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd)
+{
+ return kfifo_get(&cxl_cper_fifo, wd);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_cper_kfifo_get, "CXL");
+
/*
* GHES error status reporting throttle, to report more kinds of
* errors, instead of just most frequently occurred errors.
diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
index 51725f25c516..dd49e9179b63 100644
--- a/include/acpi/ghes_cper.h
+++ b/include/acpi/ghes_cper.h
@@ -20,6 +20,7 @@
#include <linux/workqueue.h>
#include <acpi/ghes.h>
+#include <cxl/event.h>
#define GHES_PFX "GHES: "
@@ -106,5 +107,15 @@ void ghes_estatus_cache_add(struct acpi_hest_generic *generic,
struct acpi_hest_generic_status *estatus);
void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
int sev);
+void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err,
+ int severity);
+int cxl_cper_register_prot_err_work(struct work_struct *work);
+int cxl_cper_unregister_prot_err_work(struct work_struct *work);
+int cxl_cper_prot_err_kfifo_get(struct cxl_cper_prot_err_work_data *wd);
+void cxl_cper_post_event(enum cxl_event_type event_type,
+ struct cxl_cper_event_rec *rec);
+int cxl_cper_register_work(struct work_struct *work);
+int cxl_cper_unregister_work(struct work_struct *work);
+int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd);
#endif /* ACPI_APEI_GHES_CPER_H */
--
2.43.0
^ permalink raw reply related
* Re: [PATCH 00/12] misc/syncobj: add /dev/syncobj device
From: Christian König @ 2026-05-18 11:58 UTC (permalink / raw)
To: Julian Orth, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann,
David Airlie, Simona Vetter, Sumit Semwal, Jonathan Corbet,
Shuah Khan, Arnd Bergmann, Greg Kroah-Hartman
Cc: dri-devel, linux-kernel, linux-media, linaro-mm-sig, linux-doc,
wayland-devel
In-Reply-To: <20260516-jorth-syncobj-v1-0-88ede9d98a81@gmail.com>
On 5/16/26 13:06, Julian Orth wrote:
> This series adds a new device /dev/syncobj that can be used to create
> and manipulate DRM syncobjs. Previously, these operations required the
> use of a DRM device and the device needed to support the DRIVER_SYNCOBJ
> and DRIVER_SYNCOBJ_TIMELINE features.
>
> There are several issues with the existing API:
>
> - Syncobjs are the only explicit sync mechanism available on wayland.
> Most compositors do not use GPU waits. Instead, they use the
> DRM_IOCTL_SYNCOBJ_EVENTFD ioctl to perform a CPU wait. Being tied to
> DRM devices means that compositors cannot consistently offer this
> feature even though no device-specific logic is involved.
Well the drm_syncobj is a container for device specific dma fences.
What could be possible instead is to pass an eventfd into Wayland, but that is something userspace needs to decide.
> - llvmpipe currently cannot offer syncobj interop because it does not
> have access to a DRM device. This means that applications using
> llvmpipe cannot present images before they have finished rendering,
> despite llvmpipe using threaded rendering.
Yeah, but that is completely intentional. You *CAN'T* use a dma_fence as completion event for llvmpipe rendering. See the kernel documentation on that.
What could be possible is to use the drm_syncobjs functionality to wait before signal, but that has different semantics.
Regards,
Christian.
> - Clients that do not use the Vulkan WSI need to manually probe /dev/dri
> for devices that support the syncobj ioctls in order to use the
> wayland syncobj protocol.
> - Similarly, clients that want to use screen capture have no equivalent
> to the WSI and are therefore forced into that path.
> - Having to keep a DRM device open has potentially negative interactions
> with GPU hotplug.
> - Having to translate between syncobj FDs and handles is troublesome in
> the compositor usecase since syncobjs come and go frequently and need
> to be cleaned up when clients disconnect.
>
> /dev/syncobj solves these issues by providing all syncobj ioctls under a
> consistent path that is not tied to any DRM device. It also operates
> directly on file descriptors instead of syncobj handles.
>
> The series starts with a number of small refactorings in drm_syncobj.c
> to make its functionality available outside of the file and without the
> need for drm_file/handle pairs.
>
> The last commit adds the /dev/syncobj module. I've added it as a misc
> device but maybe this should instead live somewhere under gpu/drm.
>
> An application using the new interface can be found at [1].
>
> [1]: https://github.com/mahkoh/jay/pull/947
>
> ---
> Julian Orth (12):
> drm/syncobj: add drm_syncobj_from_fd
> drm/syncobj: add drm_syncobj_fence_lookup
> drm/syncobj: make drm_syncobj_array_wait_timeout public
> drm/syncobj: add drm_syncobj_register_eventfd
> drm/syncobj: have transfer functions accept drm_syncobj directly
> drm/syncobj: add drm_syncobj_transfer
> drm/syncobj: add drm_syncobj_timeline_signal
> drm/syncobj: add drm_syncobj_query
> drm/syncobj: fix resource leak in drm_syncobj_import_sync_file_fence
> drm/syncobj: add drm_syncobj_import_sync_file
> drm/syncobj: add drm_syncobj_export_sync_file
> misc/syncobj: add new device
>
> Documentation/userspace-api/ioctl/ioctl-number.rst | 1 +
> drivers/gpu/drm/drm_syncobj.c | 374 ++++++++++++++-----
> drivers/misc/Kconfig | 10 +
> drivers/misc/Makefile | 1 +
> drivers/misc/syncobj.c | 404 +++++++++++++++++++++
> include/drm/drm_syncobj.h | 21 ++
> include/uapi/linux/syncobj.h | 75 ++++
> 7 files changed, 795 insertions(+), 91 deletions(-)
> ---
> base-commit: 6916d5703ddf9a38f1f6c2cc793381a24ee914c6
> change-id: 20260516-jorth-syncobj-d4d374c8c61b
>
> Best regards,
> --
> Julian Orth <ju.orth@gmail.com>
>
^ permalink raw reply
* [PATCH v4 07/10] ACPI: APEI: introduce GHES helper
From: Ahmed Tiba @ 2026-05-18 11:57 UTC (permalink / raw)
To: rafael, bp, saket.dumbre, will, xueshuai, mchehab, krzk+dt, dave,
conor+dt, vishal.l.verma, jic23, corbet, guohanjun, dave.jiang,
catalin.marinas, lenb, tony.luck, skhan, djbw, alison.schofield,
ira.weiny, robh
Cc: Ahmed Tiba, devicetree, linux-acpi, linux-doc, Dmitry.Lamerov,
linux-cxl, Michael.Zhao2, acpica-devel, linux-kernel,
linux-arm-kernel, linux-edac
In-Reply-To: <20260518-topics-ahmtib01-ras_ffh_arm_internal_review-v4-0-42698675ba61@arm.com>
Add a dedicated GHES_CPER_HELPERS Kconfig entry so the shared helper code
can be built even when ACPI_APEI_GHES is disabled. Update the build glue
and headers to depend on the new symbol.
Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
drivers/Makefile | 1 +
drivers/acpi/Kconfig | 4 ++++
drivers/acpi/apei/Kconfig | 1 +
drivers/acpi/apei/Makefile | 2 +-
include/acpi/ghes.h | 10 ++++++----
include/cxl/event.h | 2 +-
6 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/drivers/Makefile b/drivers/Makefile
index 0841ea851847..27a664cb45ea 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -31,6 +31,7 @@ obj-y += idle/
obj-y += char/ipmi/
obj-$(CONFIG_ACPI) += acpi/
+obj-$(CONFIG_GHES_CPER_HELPERS) += acpi/apei/ghes_cper.o
# PnP must come after ACPI since it will eventually need to check if acpi
# was used and do nothing if so
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index f165d14cf61a..13ef0e99f840 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -6,6 +6,10 @@
config ARCH_SUPPORTS_ACPI
bool
+config GHES_CPER_HELPERS
+ bool
+ select UEFI_CPER
+
menuconfig ACPI
bool "ACPI (Advanced Configuration and Power Interface) Support"
depends on ARCH_SUPPORTS_ACPI
diff --git a/drivers/acpi/apei/Kconfig b/drivers/acpi/apei/Kconfig
index 428458c623f0..ddb62638eb02 100644
--- a/drivers/acpi/apei/Kconfig
+++ b/drivers/acpi/apei/Kconfig
@@ -21,6 +21,7 @@ config ACPI_APEI_GHES
bool "APEI Generic Hardware Error Source"
depends on ACPI_APEI
select ACPI_HED
+ select GHES_CPER_HELPERS
select IRQ_WORK
select GENERIC_ALLOCATOR
select ARM_SDE_INTERFACE if ARM64
diff --git a/drivers/acpi/apei/Makefile b/drivers/acpi/apei/Makefile
index f57f3b009d8e..66588d6be56f 100644
--- a/drivers/acpi/apei/Makefile
+++ b/drivers/acpi/apei/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_ACPI_APEI) += apei.o
-obj-$(CONFIG_ACPI_APEI_GHES) += ghes.o ghes_cper.o
+obj-$(CONFIG_ACPI_APEI_GHES) += ghes.o
# clang versions prior to 18 may blow out the stack with KASAN
ifeq ($(CONFIG_COMPILE_TEST)_$(CONFIG_CC_IS_CLANG)_$(call clang-min-version, 180000),y_y_)
KASAN_SANITIZE_ghes.o := n
diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h
index 8d7e5caef3f1..2ffab36b6154 100644
--- a/include/acpi/ghes.h
+++ b/include/acpi/ghes.h
@@ -83,15 +83,17 @@ int devm_ghes_register_vendor_record_notifier(struct device *dev,
struct notifier_block *nb);
struct list_head *ghes_get_devices(void);
-
-void ghes_estatus_pool_region_free(unsigned long addr, u32 size);
#else
static inline struct list_head *ghes_get_devices(void) { return NULL; }
-
-static inline void ghes_estatus_pool_region_free(unsigned long addr, u32 size) { return; }
#endif
+#ifdef CONFIG_GHES_CPER_HELPERS
int ghes_estatus_pool_init(unsigned int num_ghes);
+void ghes_estatus_pool_region_free(unsigned long addr, u32 size);
+#else
+static inline int ghes_estatus_pool_init(unsigned int num_ghes) { return -ENODEV; }
+static inline void ghes_estatus_pool_region_free(unsigned long addr, u32 size) { }
+#endif
static inline int acpi_hest_get_version(struct acpi_hest_generic_data *gdata)
{
diff --git a/include/cxl/event.h b/include/cxl/event.h
index ff97fea718d2..2ebd65b0d9d6 100644
--- a/include/cxl/event.h
+++ b/include/cxl/event.h
@@ -285,7 +285,7 @@ struct cxl_cper_prot_err_work_data {
int severity;
};
-#ifdef CONFIG_ACPI_APEI_GHES
+#ifdef CONFIG_GHES_CPER_HELPERS
int cxl_cper_register_work(struct work_struct *work);
int cxl_cper_unregister_work(struct work_struct *work);
int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd);
--
2.43.0
^ permalink raw reply related
* [PATCH v4 08/10] ACPI: APEI: share GHES CPER helpers
From: Ahmed Tiba @ 2026-05-18 11:57 UTC (permalink / raw)
To: rafael, bp, saket.dumbre, will, xueshuai, mchehab, krzk+dt, dave,
conor+dt, vishal.l.verma, jic23, corbet, guohanjun, dave.jiang,
catalin.marinas, lenb, tony.luck, skhan, djbw, alison.schofield,
ira.weiny, robh
Cc: Ahmed Tiba, devicetree, linux-acpi, linux-doc, Dmitry.Lamerov,
linux-cxl, Michael.Zhao2, acpica-devel, linux-kernel,
linux-arm-kernel, linux-edac
In-Reply-To: <20260518-topics-ahmtib01-ras_ffh_arm_internal_review-v4-0-42698675ba61@arm.com>
Wire GHES up to the helper routines in ghes_cper.c and remove the local
copies from ghes.c. This keeps the control flow identical while letting
the helpers be shared with other firmware-first providers.
Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
drivers/acpi/apei/ghes.c | 416 +--------------------------------------
drivers/acpi/apei/ghes_cper.c | 438 +++++++++++++++++++++++++++++++++++++++++-
include/acpi/ghes_cper.h | 20 ++
3 files changed, 459 insertions(+), 415 deletions(-)
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 85be2ebf4d3e..f85b97c4db4c 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -67,8 +67,6 @@
#define FIX_APEI_GHES_SDEI_CRITICAL __end_of_fixed_addresses
#endif
-static ATOMIC_NOTIFIER_HEAD(ghes_report_chain);
-
/*
* This driver isn't really modular, however for the time being,
* continuing to use module_param is the easiest way to remain
@@ -113,276 +111,6 @@ static DEFINE_MUTEX(ghes_devs_mutex);
*/
static DEFINE_SPINLOCK(ghes_notify_lock_irq);
-struct gen_pool *ghes_estatus_pool;
-
-int ghes_estatus_pool_init(unsigned int num_ghes)
-{
- unsigned long addr, len;
- int rc;
-
- ghes_estatus_pool = gen_pool_create(GHES_ESTATUS_POOL_MIN_ALLOC_ORDER, -1);
- if (!ghes_estatus_pool)
- return -ENOMEM;
-
- len = GHES_ESTATUS_CACHE_AVG_SIZE * GHES_ESTATUS_CACHE_ALLOCED_MAX;
- len += (num_ghes * GHES_ESOURCE_PREALLOC_MAX_SIZE);
-
- addr = (unsigned long)vmalloc(PAGE_ALIGN(len));
- if (!addr)
- goto err_pool_alloc;
-
- rc = gen_pool_add(ghes_estatus_pool, addr, PAGE_ALIGN(len), -1);
- if (rc)
- goto err_pool_add;
-
- return 0;
-
-err_pool_add:
- vfree((void *)addr);
-
-err_pool_alloc:
- gen_pool_destroy(ghes_estatus_pool);
-
- return -ENOMEM;
-}
-
-/**
- * ghes_estatus_pool_region_free - free previously allocated memory
- * from the ghes_estatus_pool.
- * @addr: address of memory to free.
- * @size: size of memory to free.
- *
- * Returns none.
- */
-void ghes_estatus_pool_region_free(unsigned long addr, u32 size)
-{
- gen_pool_free(ghes_estatus_pool, addr, size);
-}
-EXPORT_SYMBOL_GPL(ghes_estatus_pool_region_free);
-
-static inline int ghes_severity(int severity)
-{
- switch (severity) {
- case CPER_SEV_INFORMATIONAL:
- return GHES_SEV_NO;
- case CPER_SEV_CORRECTED:
- return GHES_SEV_CORRECTED;
- case CPER_SEV_RECOVERABLE:
- return GHES_SEV_RECOVERABLE;
- case CPER_SEV_FATAL:
- return GHES_SEV_PANIC;
- default:
- /* Unknown, go panic */
- return GHES_SEV_PANIC;
- }
-}
-
-
-/**
- * struct ghes_task_work - for synchronous RAS event
- *
- * @twork: callback_head for task work
- * @pfn: page frame number of corrupted page
- * @flags: work control flags
- *
- * Structure to pass task work to be handled before
- * returning to user-space via task_work_add().
- */
-struct ghes_task_work {
- struct callback_head twork;
- u64 pfn;
- int flags;
-};
-
-static void memory_failure_cb(struct callback_head *twork)
-{
- struct ghes_task_work *twcb = container_of(twork, struct ghes_task_work, twork);
- int ret;
-
- ret = memory_failure(twcb->pfn, twcb->flags);
- gen_pool_free(ghes_estatus_pool, (unsigned long)twcb, sizeof(*twcb));
-
- if (!ret || ret == -EHWPOISON || ret == -EOPNOTSUPP)
- return;
-
- pr_err("%#llx: Sending SIGBUS to %s:%d due to hardware memory corruption\n",
- twcb->pfn, current->comm, task_pid_nr(current));
- force_sig(SIGBUS);
-}
-
-static bool ghes_do_memory_failure(u64 physical_addr, int flags)
-{
- struct ghes_task_work *twcb;
- unsigned long pfn;
-
- if (!IS_ENABLED(CONFIG_ACPI_APEI_MEMORY_FAILURE))
- return false;
-
- pfn = PHYS_PFN(physical_addr);
-
- if (flags == MF_ACTION_REQUIRED && current->mm) {
- twcb = (void *)gen_pool_alloc(ghes_estatus_pool, sizeof(*twcb));
- if (!twcb)
- return false;
-
- twcb->pfn = pfn;
- twcb->flags = flags;
- init_task_work(&twcb->twork, memory_failure_cb);
- task_work_add(current, &twcb->twork, TWA_RESUME);
- return true;
- }
-
- memory_failure_queue(pfn, flags);
- return true;
-}
-
-static bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata,
- int sev, bool sync)
-{
- int flags = -1;
- int sec_sev = ghes_severity(gdata->error_severity);
- struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
-
- if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
- return false;
-
- /* iff following two events can be handled properly by now */
- if (sec_sev == GHES_SEV_CORRECTED &&
- (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED))
- flags = MF_SOFT_OFFLINE;
- if (sev == GHES_SEV_RECOVERABLE && sec_sev == GHES_SEV_RECOVERABLE)
- flags = sync ? MF_ACTION_REQUIRED : 0;
-
- if (flags != -1)
- return ghes_do_memory_failure(mem_err->physical_addr, flags);
-
- return false;
-}
-
-static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata,
- int sev, bool sync)
-{
- struct cper_sec_proc_arm *err = acpi_hest_get_payload(gdata);
- int flags = sync ? MF_ACTION_REQUIRED : 0;
- int length = gdata->error_data_length;
- char error_type[120];
- bool queued = false;
- int sec_sev, i;
- char *p;
-
- sec_sev = ghes_severity(gdata->error_severity);
- if (length >= sizeof(*err)) {
- log_arm_hw_error(err, sec_sev);
- } else {
- pr_warn(FW_BUG "arm error length: %d\n", length);
- pr_warn(FW_BUG "length is too small\n");
- pr_warn(FW_BUG "firmware-generated error record is incorrect\n");
- return false;
- }
-
- if (sev != GHES_SEV_RECOVERABLE || sec_sev != GHES_SEV_RECOVERABLE)
- return false;
-
- p = (char *)(err + 1);
- length -= sizeof(err);
-
- for (i = 0; i < err->err_info_num; i++) {
- struct cper_arm_err_info *err_info;
- bool is_cache, has_pa;
-
- /* Ensure we have enough data for the error info header */
- if (length < sizeof(*err_info))
- break;
-
- err_info = (struct cper_arm_err_info *)p;
-
- /* Validate the claimed length before using it */
- length -= err_info->length;
- if (length < 0)
- break;
-
- is_cache = err_info->type & CPER_ARM_CACHE_ERROR;
- has_pa = (err_info->validation_bits & CPER_ARM_INFO_VALID_PHYSICAL_ADDR);
-
- /*
- * The field (err_info->error_info & BIT(26)) is fixed to set to
- * 1 in some old firmware of HiSilicon Kunpeng920. We assume that
- * firmware won't mix corrected errors in an uncorrected section,
- * and don't filter out 'corrected' error here.
- */
- if (is_cache && has_pa) {
- queued = ghes_do_memory_failure(err_info->physical_fault_addr, flags);
- p += err_info->length;
- continue;
- }
-
- cper_bits_to_str(error_type, sizeof(error_type),
- FIELD_GET(CPER_ARM_ERR_TYPE_MASK, err_info->type),
- cper_proc_error_type_strs,
- ARRAY_SIZE(cper_proc_error_type_strs));
-
- pr_warn_ratelimited(FW_WARN GHES_PFX
- "Unhandled processor error type 0x%02x: %s%s\n",
- err_info->type, error_type,
- (err_info->type & ~CPER_ARM_ERR_TYPE_MASK) ? " with reserved bit(s)" : "");
- p += err_info->length;
- }
-
- return queued;
-}
-
-/*
- * PCIe AER errors need to be sent to the AER driver for reporting and
- * recovery. The GHES severities map to the following AER severities and
- * require the following handling:
- *
- * GHES_SEV_CORRECTABLE -> AER_CORRECTABLE
- * These need to be reported by the AER driver but no recovery is
- * necessary.
- * GHES_SEV_RECOVERABLE -> AER_NONFATAL
- * GHES_SEV_RECOVERABLE && CPER_SEC_RESET -> AER_FATAL
- * These both need to be reported and recovered from by the AER driver.
- * GHES_SEV_PANIC does not make it to this handling since the kernel must
- * panic.
- */
-static void ghes_handle_aer(struct acpi_hest_generic_data *gdata)
-{
-#ifdef CONFIG_ACPI_APEI_PCIEAER
- struct cper_sec_pcie *pcie_err = acpi_hest_get_payload(gdata);
-
- if (pcie_err->validation_bits & CPER_PCIE_VALID_DEVICE_ID &&
- pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO) {
- unsigned int devfn;
- int aer_severity;
- u8 *aer_info;
-
- devfn = PCI_DEVFN(pcie_err->device_id.device,
- pcie_err->device_id.function);
- aer_severity = cper_severity_to_aer(gdata->error_severity);
-
- /*
- * If firmware reset the component to contain
- * the error, we must reinitialize it before
- * use, so treat it as a fatal AER error.
- */
- if (gdata->flags & CPER_SEC_RESET)
- aer_severity = AER_FATAL;
-
- aer_info = (void *)gen_pool_alloc(ghes_estatus_pool,
- sizeof(struct aer_capability_regs));
- if (!aer_info)
- return;
- memcpy(aer_info, pcie_err->aer_info, sizeof(struct aer_capability_regs));
-
- aer_recover_queue(pcie_err->device_id.segment,
- pcie_err->device_id.bus,
- devfn, aer_severity,
- (struct aer_capability_regs *)
- aer_info);
- }
-#endif
-}
-
static void ghes_vendor_record_notifier_destroy(void *nb)
{
ghes_unregister_vendor_record_notifier(nb);
@@ -401,151 +129,11 @@ int devm_ghes_register_vendor_record_notifier(struct device *dev,
}
EXPORT_SYMBOL_GPL(devm_ghes_register_vendor_record_notifier);
-static void ghes_log_hwerr(int sev, guid_t *sec_type)
-{
- if (sev != CPER_SEV_RECOVERABLE)
- return;
-
- if (guid_equal(sec_type, &CPER_SEC_PROC_ARM) ||
- guid_equal(sec_type, &CPER_SEC_PROC_GENERIC) ||
- guid_equal(sec_type, &CPER_SEC_PROC_IA)) {
- hwerr_log_error_type(HWERR_RECOV_CPU);
- return;
- }
-
- if (guid_equal(sec_type, &CPER_SEC_CXL_PROT_ERR) ||
- guid_equal(sec_type, &CPER_SEC_CXL_GEN_MEDIA_GUID) ||
- guid_equal(sec_type, &CPER_SEC_CXL_DRAM_GUID) ||
- guid_equal(sec_type, &CPER_SEC_CXL_MEM_MODULE_GUID)) {
- hwerr_log_error_type(HWERR_RECOV_CXL);
- return;
- }
-
- if (guid_equal(sec_type, &CPER_SEC_PCIE) ||
- guid_equal(sec_type, &CPER_SEC_PCI_X_BUS)) {
- hwerr_log_error_type(HWERR_RECOV_PCI);
- return;
- }
-
- if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
- hwerr_log_error_type(HWERR_RECOV_MEMORY);
- return;
- }
-
- hwerr_log_error_type(HWERR_RECOV_OTHERS);
-}
-
static void ghes_do_proc(struct ghes *ghes,
const struct acpi_hest_generic_status *estatus)
{
- int sev, sec_sev;
- struct acpi_hest_generic_data *gdata;
- guid_t *sec_type;
- const guid_t *fru_id = &guid_null;
- char *fru_text = "";
- bool queued = false;
- bool sync = is_hest_sync_notify(ghes);
-
- sev = ghes_severity(estatus->error_severity);
- apei_estatus_for_each_section(estatus, gdata) {
- sec_type = (guid_t *)gdata->section_type;
- sec_sev = ghes_severity(gdata->error_severity);
- if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
- fru_id = (guid_t *)gdata->fru_id;
-
- if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
- fru_text = gdata->fru_text;
-
- ghes_log_hwerr(sev, sec_type);
- if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
- struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
-
- atomic_notifier_call_chain(&ghes_report_chain, sev, mem_err);
-
- arch_apei_report_mem_error(sev, mem_err);
- queued = ghes_handle_memory_failure(gdata, sev, sync);
- } else if (guid_equal(sec_type, &CPER_SEC_PCIE)) {
- ghes_handle_aer(gdata);
- } else if (guid_equal(sec_type, &CPER_SEC_PROC_ARM)) {
- queued = ghes_handle_arm_hw_error(gdata, sev, sync);
- } else if (guid_equal(sec_type, &CPER_SEC_CXL_PROT_ERR)) {
- struct cxl_cper_sec_prot_err *prot_err = acpi_hest_get_payload(gdata);
-
- cxl_cper_post_prot_err(prot_err, gdata->error_severity);
- } else if (guid_equal(sec_type, &CPER_SEC_CXL_GEN_MEDIA_GUID)) {
- struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
-
- cxl_cper_post_event(CXL_CPER_EVENT_GEN_MEDIA, rec);
- } else if (guid_equal(sec_type, &CPER_SEC_CXL_DRAM_GUID)) {
- struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
-
- cxl_cper_post_event(CXL_CPER_EVENT_DRAM, rec);
- } else if (guid_equal(sec_type, &CPER_SEC_CXL_MEM_MODULE_GUID)) {
- struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
-
- cxl_cper_post_event(CXL_CPER_EVENT_MEM_MODULE, rec);
- } else {
- void *err = acpi_hest_get_payload(gdata);
-
- ghes_defer_non_standard_event(gdata, sev);
- log_non_standard_event(sec_type, fru_id, fru_text,
- sec_sev, err,
- gdata->error_data_length);
- }
- }
-
- /*
- * If no memory failure work is queued for abnormal synchronous
- * errors, do a force kill.
- */
- if (sync && !queued) {
- dev_err(ghes->dev,
- HW_ERR GHES_PFX "%s:%d: synchronous unrecoverable error (SIGBUS)\n",
- current->comm, task_pid_nr(current));
- force_sig(SIGBUS);
- }
-}
-
-static void __ghes_print_estatus(const char *pfx,
- const struct acpi_hest_generic *generic,
- const struct acpi_hest_generic_status *estatus)
-{
- static atomic_t seqno;
- unsigned int curr_seqno;
- char pfx_seq[64];
-
- if (pfx == NULL) {
- if (ghes_severity(estatus->error_severity) <=
- GHES_SEV_CORRECTED)
- pfx = KERN_WARNING;
- else
- pfx = KERN_ERR;
- }
- curr_seqno = atomic_inc_return(&seqno);
- snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}" HW_ERR, pfx, curr_seqno);
- printk("%s""Hardware error from APEI Generic Hardware Error Source: %d\n",
- pfx_seq, generic->header.source_id);
- cper_estatus_print(pfx_seq, estatus);
-}
-
-static int ghes_print_estatus(const char *pfx,
- const struct acpi_hest_generic *generic,
- const struct acpi_hest_generic_status *estatus)
-{
- /* Not more than 2 messages every 5 seconds */
- static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
- static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
- struct ratelimit_state *ratelimit;
-
- if (ghes_severity(estatus->error_severity) <= GHES_SEV_CORRECTED)
- ratelimit = &ratelimit_corrected;
- else
- ratelimit = &ratelimit_uncorrected;
- if (__ratelimit(ratelimit)) {
- __ghes_print_estatus(pfx, generic, estatus);
- return 1;
- }
- return 0;
+ ghes_cper_handle_status(ghes->dev, ghes->generic,
+ estatus, is_hest_sync_notify(ghes));
}
static void __ghes_panic(struct ghes *ghes,
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
index d7a666a163c3..0ff9d06eb78f 100644
--- a/drivers/acpi/apei/ghes_cper.c
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -13,22 +13,32 @@
*/
#include <linux/aer.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
#include <linux/err.h>
#include <linux/genalloc.h>
-#include <linux/irq_work.h>
#include <linux/io.h>
+#include <linux/irq_work.h>
#include <linux/kfifo.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/math64.h>
#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/uuid.h>
+#include <linux/sched/signal.h>
+#include <linux/task_work.h>
#include <linux/notifier.h>
#include <linux/llist.h>
+#include <linux/ras.h>
+#include <ras/ras_event.h>
#include <linux/ratelimit.h>
#include <linux/rcupdate.h>
#include <linux/rculist.h>
#include <linux/sched/clock.h>
#include <linux/slab.h>
+#include <linux/vmcore_info.h>
+#include <linux/vmalloc.h>
#include <acpi/apei.h>
#include <acpi/ghes_cper.h>
@@ -38,9 +48,363 @@
#include "apei-internal.h"
+ATOMIC_NOTIFIER_HEAD(ghes_report_chain);
+
+#ifndef CONFIG_ACPI_APEI
+void __weak arch_apei_report_mem_error(int sev, struct cper_sec_mem_err *mem_err) { }
+#endif
+
static struct ghes_estatus_cache __rcu *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
static atomic_t ghes_estatus_cache_alloced;
+struct gen_pool *ghes_estatus_pool;
+
+int ghes_estatus_pool_init(unsigned int num_ghes)
+{
+ unsigned long addr, len;
+ int rc;
+
+ ghes_estatus_pool = gen_pool_create(GHES_ESTATUS_POOL_MIN_ALLOC_ORDER, -1);
+ if (!ghes_estatus_pool)
+ return -ENOMEM;
+
+ len = GHES_ESTATUS_CACHE_AVG_SIZE * GHES_ESTATUS_CACHE_ALLOCED_MAX;
+ len += (num_ghes * GHES_ESOURCE_PREALLOC_MAX_SIZE);
+
+ addr = (unsigned long)vmalloc(PAGE_ALIGN(len));
+ if (!addr)
+ goto err_pool_alloc;
+
+ rc = gen_pool_add(ghes_estatus_pool, addr, PAGE_ALIGN(len), -1);
+ if (rc)
+ goto err_pool_add;
+
+ return 0;
+
+err_pool_add:
+ vfree((void *)addr);
+
+err_pool_alloc:
+ gen_pool_destroy(ghes_estatus_pool);
+
+ return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(ghes_estatus_pool_init);
+
+/**
+ * ghes_estatus_pool_region_free - free previously allocated memory
+ * from the ghes_estatus_pool.
+ * @addr: address of memory to free.
+ * @size: size of memory to free.
+ *
+ * Returns none.
+ */
+void ghes_estatus_pool_region_free(unsigned long addr, u32 size)
+{
+ gen_pool_free(ghes_estatus_pool, addr, size);
+}
+EXPORT_SYMBOL_GPL(ghes_estatus_pool_region_free);
+
+int ghes_severity(int severity)
+{
+ switch (severity) {
+ case CPER_SEV_INFORMATIONAL:
+ return GHES_SEV_NO;
+ case CPER_SEV_CORRECTED:
+ return GHES_SEV_CORRECTED;
+ case CPER_SEV_RECOVERABLE:
+ return GHES_SEV_RECOVERABLE;
+ case CPER_SEV_FATAL:
+ return GHES_SEV_PANIC;
+ default:
+ /* Unknown, go panic */
+ return GHES_SEV_PANIC;
+ }
+}
+
+/**
+ * struct ghes_task_work - for synchronous RAS event
+ *
+ * @twork: callback_head for task work
+ * @pfn: page frame number of corrupted page
+ * @flags: work control flags
+ *
+ * Structure to pass task work to be handled before
+ * returning to user-space via task_work_add().
+ */
+struct ghes_task_work {
+ struct callback_head twork;
+ u64 pfn;
+ int flags;
+};
+
+static void memory_failure_cb(struct callback_head *twork)
+{
+ struct ghes_task_work *twcb = container_of(twork, struct ghes_task_work, twork);
+ int ret;
+
+ ret = memory_failure(twcb->pfn, twcb->flags);
+ gen_pool_free(ghes_estatus_pool, (unsigned long)twcb, sizeof(*twcb));
+
+ if (!ret || ret == -EHWPOISON || ret == -EOPNOTSUPP)
+ return;
+
+ pr_err("%#llx: Sending SIGBUS to %s:%d due to hardware memory corruption\n",
+ twcb->pfn, current->comm, task_pid_nr(current));
+ force_sig(SIGBUS);
+}
+
+static bool ghes_do_memory_failure(u64 physical_addr, int flags)
+{
+ struct ghes_task_work *twcb;
+ unsigned long pfn;
+
+ if (!IS_ENABLED(CONFIG_ACPI_APEI_MEMORY_FAILURE))
+ return false;
+
+ pfn = PHYS_PFN(physical_addr);
+
+ if (flags == MF_ACTION_REQUIRED && current->mm) {
+ twcb = (void *)gen_pool_alloc(ghes_estatus_pool, sizeof(*twcb));
+ if (!twcb)
+ return false;
+
+ twcb->pfn = pfn;
+ twcb->flags = flags;
+ init_task_work(&twcb->twork, memory_failure_cb);
+ task_work_add(current, &twcb->twork, TWA_RESUME);
+ return true;
+ }
+
+ memory_failure_queue(pfn, flags);
+ return true;
+}
+
+bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata,
+ int sev, bool sync)
+{
+ int flags = -1;
+ int sec_sev = ghes_severity(gdata->error_severity);
+ struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
+
+ if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
+ return false;
+
+ /* iff following two events can be handled properly by now */
+ if (sec_sev == GHES_SEV_CORRECTED &&
+ (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED))
+ flags = MF_SOFT_OFFLINE;
+ if (sev == GHES_SEV_RECOVERABLE && sec_sev == GHES_SEV_RECOVERABLE)
+ flags = sync ? MF_ACTION_REQUIRED : 0;
+
+ if (flags != -1)
+ return ghes_do_memory_failure(mem_err->physical_addr, flags);
+
+ return false;
+}
+
+bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata,
+ int sev, bool sync)
+{
+ struct cper_sec_proc_arm *err = acpi_hest_get_payload(gdata);
+ int flags = sync ? MF_ACTION_REQUIRED : 0;
+ int length = gdata->error_data_length;
+ char error_type[120];
+ bool queued = false;
+ int sec_sev, i;
+ char *p;
+
+ sec_sev = ghes_severity(gdata->error_severity);
+ if (length >= sizeof(*err)) {
+ log_arm_hw_error(err, sec_sev);
+ } else {
+ pr_warn(FW_BUG "arm error length: %d\n", length);
+ pr_warn(FW_BUG "length is too small\n");
+ pr_warn(FW_BUG "firmware-generated error record is incorrect\n");
+ return false;
+ }
+
+ if (sev != GHES_SEV_RECOVERABLE || sec_sev != GHES_SEV_RECOVERABLE)
+ return false;
+
+ p = (char *)(err + 1);
+ length -= sizeof(err);
+
+ for (i = 0; i < err->err_info_num; i++) {
+ struct cper_arm_err_info *err_info;
+ bool is_cache, has_pa;
+
+ /* Ensure we have enough data for the error info header */
+ if (length < sizeof(*err_info))
+ break;
+
+ err_info = (struct cper_arm_err_info *)p;
+
+ /* Validate the claimed length before using it */
+ length -= err_info->length;
+ if (length < 0)
+ break;
+
+ is_cache = err_info->type & CPER_ARM_CACHE_ERROR;
+ has_pa = (err_info->validation_bits & CPER_ARM_INFO_VALID_PHYSICAL_ADDR);
+
+ /*
+ * The field (err_info->error_info & BIT(26)) is fixed to set to
+ * 1 in some old firmware of HiSilicon Kunpeng920. We assume that
+ * firmware won't mix corrected errors in an uncorrected section,
+ * and don't filter out 'corrected' error here.
+ */
+ if (is_cache && has_pa) {
+ queued = ghes_do_memory_failure(err_info->physical_fault_addr, flags);
+ p += err_info->length;
+ continue;
+ }
+
+ cper_bits_to_str(error_type, sizeof(error_type),
+ FIELD_GET(CPER_ARM_ERR_TYPE_MASK, err_info->type),
+ cper_proc_error_type_strs,
+ ARRAY_SIZE(cper_proc_error_type_strs));
+
+ pr_warn_ratelimited(FW_WARN GHES_PFX
+ "Unhandled processor error type 0x%02x: %s%s\n",
+ err_info->type, error_type,
+ err_info->type & ~CPER_ARM_ERR_TYPE_MASK ?
+ " with reserved bit(s)" : "");
+ p += err_info->length;
+ }
+
+ return queued;
+}
+
+/*
+ * PCIe AER errors need to be sent to the AER driver for reporting and
+ * recovery. The GHES severities map to the following AER severities and
+ * require the following handling:
+ *
+ * GHES_SEV_CORRECTABLE -> AER_CORRECTABLE
+ * These need to be reported by the AER driver but no recovery is
+ * necessary.
+ * GHES_SEV_RECOVERABLE -> AER_NONFATAL
+ * GHES_SEV_RECOVERABLE && CPER_SEC_RESET -> AER_FATAL
+ * These both need to be reported and recovered from by the AER driver.
+ * GHES_SEV_PANIC does not make it to this handling since the kernel must
+ * panic.
+ */
+void ghes_handle_aer(struct acpi_hest_generic_data *gdata)
+{
+#ifdef CONFIG_ACPI_APEI_PCIEAER
+ struct cper_sec_pcie *pcie_err = acpi_hest_get_payload(gdata);
+
+ if (pcie_err->validation_bits & CPER_PCIE_VALID_DEVICE_ID &&
+ pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO) {
+ unsigned int devfn;
+ int aer_severity;
+ u8 *aer_info;
+
+ devfn = PCI_DEVFN(pcie_err->device_id.device,
+ pcie_err->device_id.function);
+ aer_severity = cper_severity_to_aer(gdata->error_severity);
+
+ /*
+ * If firmware reset the component to contain
+ * the error, we must reinitialize it before
+ * use, so treat it as a fatal AER error.
+ */
+ if (gdata->flags & CPER_SEC_RESET)
+ aer_severity = AER_FATAL;
+
+ aer_info = (void *)gen_pool_alloc(ghes_estatus_pool,
+ sizeof(struct aer_capability_regs));
+ if (!aer_info)
+ return;
+ memcpy(aer_info, pcie_err->aer_info, sizeof(struct aer_capability_regs));
+
+ aer_recover_queue(pcie_err->device_id.segment,
+ pcie_err->device_id.bus,
+ devfn, aer_severity,
+ (struct aer_capability_regs *)
+ aer_info);
+ }
+#endif
+}
+
+void ghes_log_hwerr(int sev, guid_t *sec_type)
+{
+ if (sev != CPER_SEV_RECOVERABLE)
+ return;
+
+ if (guid_equal(sec_type, &CPER_SEC_PROC_ARM) ||
+ guid_equal(sec_type, &CPER_SEC_PROC_GENERIC) ||
+ guid_equal(sec_type, &CPER_SEC_PROC_IA)) {
+ hwerr_log_error_type(HWERR_RECOV_CPU);
+ return;
+ }
+
+ if (guid_equal(sec_type, &CPER_SEC_CXL_PROT_ERR) ||
+ guid_equal(sec_type, &CPER_SEC_CXL_GEN_MEDIA_GUID) ||
+ guid_equal(sec_type, &CPER_SEC_CXL_DRAM_GUID) ||
+ guid_equal(sec_type, &CPER_SEC_CXL_MEM_MODULE_GUID)) {
+ hwerr_log_error_type(HWERR_RECOV_CXL);
+ return;
+ }
+
+ if (guid_equal(sec_type, &CPER_SEC_PCIE) ||
+ guid_equal(sec_type, &CPER_SEC_PCI_X_BUS)) {
+ hwerr_log_error_type(HWERR_RECOV_PCI);
+ return;
+ }
+
+ if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
+ hwerr_log_error_type(HWERR_RECOV_MEMORY);
+ return;
+ }
+
+ hwerr_log_error_type(HWERR_RECOV_OTHERS);
+}
+
+void __ghes_print_estatus(const char *pfx,
+ const struct acpi_hest_generic *generic,
+ const struct acpi_hest_generic_status *estatus)
+{
+ static atomic_t seqno;
+ unsigned int curr_seqno;
+ char pfx_seq[64];
+
+ if (!pfx) {
+ if (ghes_severity(estatus->error_severity) <=
+ GHES_SEV_CORRECTED)
+ pfx = KERN_WARNING;
+ else
+ pfx = KERN_ERR;
+ }
+ curr_seqno = atomic_inc_return(&seqno);
+ snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}" HW_ERR, pfx, curr_seqno);
+ printk("%sHardware error from APEI Generic Hardware Error Source: %d\n",
+ pfx_seq, generic->header.source_id);
+ cper_estatus_print(pfx_seq, estatus);
+}
+
+int ghes_print_estatus(const char *pfx,
+ const struct acpi_hest_generic *generic,
+ const struct acpi_hest_generic_status *estatus)
+{
+ /* Not more than 2 messages every 5 seconds */
+ static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5 * HZ, 2);
+ static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5 * HZ, 2);
+ struct ratelimit_state *ratelimit;
+
+ if (ghes_severity(estatus->error_severity) <= GHES_SEV_CORRECTED)
+ ratelimit = &ratelimit_corrected;
+ else
+ ratelimit = &ratelimit_uncorrected;
+ if (__ratelimit(ratelimit)) {
+ __ghes_print_estatus(pfx, generic, estatus);
+ return 1;
+ }
+ return 0;
+}
+
+#ifdef CONFIG_ACPI_APEI
static void __iomem *ghes_map(u64 pfn, enum fixed_addresses fixmap_idx)
{
phys_addr_t paddr;
@@ -272,6 +636,7 @@ void ghes_clear_estatus(struct ghes *ghes,
if (is_hest_type_generic_v2(ghes))
ghes_ack_error(ghes->generic_v2);
}
+#endif /* CONFIG_ACPI_APEI */
static BLOCKING_NOTIFIER_HEAD(vendor_record_notify_list);
@@ -323,6 +688,77 @@ void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
schedule_work(&entry->work);
}
+void ghes_cper_handle_status(struct device *dev,
+ const struct acpi_hest_generic *generic,
+ const struct acpi_hest_generic_status *estatus,
+ bool sync)
+{
+ int sev, sec_sev;
+ struct acpi_hest_generic_data *gdata;
+ guid_t *sec_type;
+ const guid_t *fru_id = &guid_null;
+ char *fru_text = "";
+ bool queued = false;
+
+ sev = ghes_severity(estatus->error_severity);
+ apei_estatus_for_each_section(estatus, gdata) {
+ sec_type = (guid_t *)gdata->section_type;
+ sec_sev = ghes_severity(gdata->error_severity);
+ if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
+ fru_id = (guid_t *)gdata->fru_id;
+
+ if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
+ fru_text = gdata->fru_text;
+
+ ghes_log_hwerr(sev, sec_type);
+ if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
+ struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
+
+ atomic_notifier_call_chain(&ghes_report_chain, sev, mem_err);
+
+ arch_apei_report_mem_error(sev, mem_err);
+ queued = ghes_handle_memory_failure(gdata, sev, sync);
+ } else if (guid_equal(sec_type, &CPER_SEC_PCIE)) {
+ ghes_handle_aer(gdata);
+ } else if (guid_equal(sec_type, &CPER_SEC_PROC_ARM)) {
+ queued = ghes_handle_arm_hw_error(gdata, sev, sync);
+ } else if (guid_equal(sec_type, &CPER_SEC_CXL_PROT_ERR)) {
+ struct cxl_cper_sec_prot_err *prot_err = acpi_hest_get_payload(gdata);
+
+ cxl_cper_post_prot_err(prot_err, gdata->error_severity);
+ } else if (guid_equal(sec_type, &CPER_SEC_CXL_GEN_MEDIA_GUID)) {
+ struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
+
+ cxl_cper_post_event(CXL_CPER_EVENT_GEN_MEDIA, rec);
+ } else if (guid_equal(sec_type, &CPER_SEC_CXL_DRAM_GUID)) {
+ struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
+
+ cxl_cper_post_event(CXL_CPER_EVENT_DRAM, rec);
+ } else if (guid_equal(sec_type, &CPER_SEC_CXL_MEM_MODULE_GUID)) {
+ struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
+
+ cxl_cper_post_event(CXL_CPER_EVENT_MEM_MODULE, rec);
+ } else {
+ void *err = acpi_hest_get_payload(gdata);
+
+ ghes_defer_non_standard_event(gdata, sev);
+ log_non_standard_event(sec_type, fru_id, fru_text,
+ sec_sev, err,
+ gdata->error_data_length);
+ }
+ }
+
+ /*
+ * If no memory failure work is queued for abnormal synchronous
+ * errors, do a force kill.
+ */
+ if (sync && !queued) {
+ dev_err(dev,
+ HW_ERR GHES_PFX "%s:%d: synchronous unrecoverable error (SIGBUS)\n",
+ current->comm, task_pid_nr(current));
+ force_sig(SIGBUS);
+ }
+}
/* Room for 8 entries */
#define CXL_CPER_PROT_ERR_FIFO_DEPTH 8
static DEFINE_KFIFO(cxl_cper_prot_err_fifo, struct cxl_cper_prot_err_work_data,
diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
index dd49e9179b63..511b95b50911 100644
--- a/include/acpi/ghes_cper.h
+++ b/include/acpi/ghes_cper.h
@@ -17,6 +17,8 @@
#define ACPI_APEI_GHES_CPER_H
#include <linux/atomic.h>
+#include <linux/device.h>
+#include <linux/notifier.h>
#include <linux/workqueue.h>
#include <acpi/ghes.h>
@@ -57,6 +59,7 @@
((struct ghes_vendor_record_entry *)(vendor_entry) + 1))
extern struct gen_pool *ghes_estatus_pool;
+extern struct atomic_notifier_head ghes_report_chain;
static inline bool is_hest_type_generic_v2(struct ghes *ghes)
{
@@ -107,6 +110,23 @@ void ghes_estatus_cache_add(struct acpi_hest_generic *generic,
struct acpi_hest_generic_status *estatus);
void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
int sev);
+int ghes_severity(int severity);
+bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata,
+ int sev, bool sync);
+bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata,
+ int sev, bool sync);
+void ghes_handle_aer(struct acpi_hest_generic_data *gdata);
+void ghes_log_hwerr(int sev, guid_t *sec_type);
+void __ghes_print_estatus(const char *pfx,
+ const struct acpi_hest_generic *generic,
+ const struct acpi_hest_generic_status *estatus);
+int ghes_print_estatus(const char *pfx,
+ const struct acpi_hest_generic *generic,
+ const struct acpi_hest_generic_status *estatus);
+void ghes_cper_handle_status(struct device *dev,
+ const struct acpi_hest_generic *generic,
+ const struct acpi_hest_generic_status *estatus,
+ bool sync);
void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err,
int severity);
int cxl_cper_register_prot_err_work(struct work_struct *work);
--
2.43.0
^ permalink raw reply related
* [PATCH v4 09/10] dt-bindings: firmware: add arm,ras-cper
From: Ahmed Tiba @ 2026-05-18 11:57 UTC (permalink / raw)
To: rafael, bp, saket.dumbre, will, xueshuai, mchehab, krzk+dt, dave,
conor+dt, vishal.l.verma, jic23, corbet, guohanjun, dave.jiang,
catalin.marinas, lenb, tony.luck, skhan, djbw, alison.schofield,
ira.weiny, robh
Cc: Ahmed Tiba, devicetree, linux-acpi, linux-doc, Dmitry.Lamerov,
linux-cxl, Michael.Zhao2, acpica-devel, linux-kernel,
linux-arm-kernel, linux-edac
In-Reply-To: <20260518-topics-ahmtib01-ras_ffh_arm_internal_review-v4-0-42698675ba61@arm.com>
Describe the DeviceTree node that exposes the Arm firmware-first
CPER provider and hook the file into MAINTAINERS so the
binding has an owner.
Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
.../devicetree/bindings/firmware/arm,ras-cper.yaml | 71 ++++++++++++++++++++++
MAINTAINERS | 5 ++
2 files changed, 76 insertions(+)
diff --git a/Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml b/Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml
new file mode 100644
index 000000000000..81dc37390af5
--- /dev/null
+++ b/Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/firmware/arm,ras-cper.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Arm RAS CPER provider
+
+maintainers:
+ - Ahmed Tiba <ahmed.tiba@arm.com>
+
+description:
+ Arm Reliability, Availability and Serviceability (RAS) firmware can expose
+ a firmware-first CPER error source directly via DeviceTree. Firmware
+ provides the CPER Generic Error Status block and notifies the OS through
+ an interrupt.
+
+properties:
+ compatible:
+ const: arm,ras-cper
+
+ memory-region:
+ oneOf:
+ - items:
+ - description:
+ CPER Generic Error Status block exposed by firmware
+ - items:
+ - description:
+ CPER Generic Error Status block exposed by firmware.
+ - description:
+ Optional firmware-owned ack buffer used on platforms
+ where firmware needs an explicit "ack" handshake before overwriting
+ the CPER buffer. Firmware watches bit 0 and expects the OS to set it
+ once the current status block has been consumed.
+
+ interrupts:
+ maxItems: 1
+ description:
+ Interrupt used to signal that a new status record is ready.
+
+required:
+ - compatible
+ - memory-region
+ - interrupts
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+ reserved-memory {
+ #address-cells = <2>;
+ #size-cells = <2>;
+ ras_cper_buffer: memory@fe800000 {
+ reg = <0x0 0xfe800000 0x0 0x1000>;
+ no-map;
+ };
+
+ ras_cper_ack: memory@fe801000 {
+ reg = <0x0 0xfe801000 0x0 0x1000>;
+ no-map;
+ };
+ };
+
+ error-handler {
+ compatible = "arm,ras-cper";
+ memory-region = <&ras_cper_buffer>, <&ras_cper_ack>;
+ interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
+ };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 7492fefa447c..3bbc19589f1a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22251,6 +22251,11 @@ M: Alexandre Bounine <alex.bou9@gmail.com>
S: Maintained
F: drivers/rapidio/
+RAS ERROR STATUS
+M: Ahmed Tiba <ahmed.tiba@arm.com>
+S: Maintained
+F: Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml
+
RAS INFRASTRUCTURE
M: Tony Luck <tony.luck@intel.com>
M: Borislav Petkov <bp@alien8.de>
--
2.43.0
^ permalink raw reply related
* [PATCH v4 10/10] RAS: add firmware-first CPER provider
From: Ahmed Tiba @ 2026-05-18 11:57 UTC (permalink / raw)
To: rafael, bp, saket.dumbre, will, xueshuai, mchehab, krzk+dt, dave,
conor+dt, vishal.l.verma, jic23, corbet, guohanjun, dave.jiang,
catalin.marinas, lenb, tony.luck, skhan, djbw, alison.schofield,
ira.weiny, robh
Cc: Ahmed Tiba, devicetree, linux-acpi, linux-doc, Dmitry.Lamerov,
linux-cxl, Michael.Zhao2, acpica-devel, linux-kernel,
linux-arm-kernel, linux-edac
In-Reply-To: <20260518-topics-ahmtib01-ras_ffh_arm_internal_review-v4-0-42698675ba61@arm.com>
Add a firmware-first CPER provider that reuses the shared
GHES helpers, wire it into the RAS Kconfig/Makefile and
document it in the admin guide.
Update MAINTAINERS now that the driver exists.
Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
Documentation/admin-guide/RAS/main.rst | 18 +++
MAINTAINERS | 1 +
drivers/acpi/apei/apei-internal.h | 10 +-
drivers/acpi/apei/ghes_cper.c | 2 +
drivers/ras/Kconfig | 11 ++
drivers/ras/Makefile | 1 +
drivers/ras/cper-esource.c | 257 +++++++++++++++++++++++++++++++++
include/acpi/ghes_cper.h | 10 ++
8 files changed, 301 insertions(+), 9 deletions(-)
diff --git a/Documentation/admin-guide/RAS/main.rst b/Documentation/admin-guide/RAS/main.rst
index 5a45db32c49b..84219d25a072 100644
--- a/Documentation/admin-guide/RAS/main.rst
+++ b/Documentation/admin-guide/RAS/main.rst
@@ -205,6 +205,24 @@ Architecture (MCA)\ [#f3]_.
.. [#f3] For more details about the Machine Check Architecture (MCA),
please read Documentation/arch/x86/x86_64/machinecheck.rst at the Kernel tree.
+Firmware-first CPER providers
+-----------------------------
+
+Some systems expose Common Platform Error Record (CPER) data
+through platform firmware instead of ACPI HEST tables.
+Enable ``CONFIG_RAS_CPER_ESOURCE`` to build the ``drivers/ras/cper-esource.c``
+driver. The current in-tree firmware description uses the
+``Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml`` binding.
+The driver reuses the GHES CPER helper object in
+``drivers/acpi/apei/ghes_cper.c`` so the logging, notifier chains, and
+memory failure handling match the ACPI GHES behaviour even when
+ACPI is disabled.
+
+Once a platform describes a firmware-first provider, both ACPI GHES and the
+firmware-described driver reuse the same code paths. This keeps the
+behaviour consistent regardless of whether the error source is described
+by ACPI tables or another firmware description.
+
EDAC - Error Detection And Correction
*************************************
diff --git a/MAINTAINERS b/MAINTAINERS
index 3bbc19589f1a..8a5151a49820 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22255,6 +22255,7 @@ RAS ERROR STATUS
M: Ahmed Tiba <ahmed.tiba@arm.com>
S: Maintained
F: Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml
+F: drivers/ras/cper-esource.c
RAS INFRASTRUCTURE
M: Tony Luck <tony.luck@intel.com>
diff --git a/drivers/acpi/apei/apei-internal.h b/drivers/acpi/apei/apei-internal.h
index 77c10a7a7a9f..c16ac541f15b 100644
--- a/drivers/acpi/apei/apei-internal.h
+++ b/drivers/acpi/apei/apei-internal.h
@@ -8,6 +8,7 @@
#define APEI_INTERNAL_H
#include <linux/acpi.h>
+#include <acpi/ghes_cper.h>
struct apei_exec_context;
@@ -120,15 +121,6 @@ int apei_exec_collect_resources(struct apei_exec_context *ctx,
struct dentry;
struct dentry *apei_get_debugfs_dir(void);
-static inline u32 cper_estatus_len(struct acpi_hest_generic_status *estatus)
-{
- if (estatus->raw_data_length)
- return estatus->raw_data_offset + \
- estatus->raw_data_length;
- else
- return sizeof(*estatus) + estatus->data_length;
-}
-
int apei_osc_setup(void);
int einj_get_available_error_type(u32 *type, int einj_action);
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
index 0ff9d06eb78f..a7691aa5011c 100644
--- a/drivers/acpi/apei/ghes_cper.c
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -46,7 +46,9 @@
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
+#ifdef CONFIG_ACPI_APEI
#include "apei-internal.h"
+#endif
ATOMIC_NOTIFIER_HEAD(ghes_report_chain);
diff --git a/drivers/ras/Kconfig b/drivers/ras/Kconfig
index fc4f4bb94a4c..3c1c63b2fefc 100644
--- a/drivers/ras/Kconfig
+++ b/drivers/ras/Kconfig
@@ -34,6 +34,17 @@ if RAS
source "arch/x86/ras/Kconfig"
source "drivers/ras/amd/atl/Kconfig"
+config RAS_CPER_ESOURCE
+ bool "Firmware-first CPER error source block provider"
+ select GHES_CPER_HELPERS
+ help
+ Enable support for firmware-first Common Platform Error Record
+ (CPER) error source block providers. The current in-tree user is
+ described by the arm,ras-cper DeviceTree binding. The driver
+ reuses the existing GHES CPER helpers so the error processing
+ matches the ACPI code paths, but it can be built even when ACPI is
+ disabled.
+
config RAS_FMPM
tristate "FRU Memory Poison Manager"
default m
diff --git a/drivers/ras/Makefile b/drivers/ras/Makefile
index 11f95d59d397..0de069557f31 100644
--- a/drivers/ras/Makefile
+++ b/drivers/ras/Makefile
@@ -2,6 +2,7 @@
obj-$(CONFIG_RAS) += ras.o
obj-$(CONFIG_DEBUG_FS) += debugfs.o
obj-$(CONFIG_RAS_CEC) += cec.o
+obj-$(CONFIG_RAS_CPER_ESOURCE) += cper-esource.o
obj-$(CONFIG_RAS_FMPM) += amd/fmpm.o
obj-y += amd/atl/
diff --git a/drivers/ras/cper-esource.c b/drivers/ras/cper-esource.c
new file mode 100644
index 000000000000..83f7a910e50a
--- /dev/null
+++ b/drivers/ras/cper-esource.c
@@ -0,0 +1,257 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Firmware-first CPER error source provider.
+ *
+ * This driver shares the GHES CPER helpers so we keep the reporting and
+ * notifier behaviour identical to ACPI GHES.
+ *
+ * Copyright (C) 2026 ARM Ltd.
+ * Author: Ahmed Tiba <ahmed.tiba@arm.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/cleanup.h>
+#include <linux/idr.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/panic.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <acpi/ghes.h>
+#include <acpi/ghes_cper.h>
+
+static DEFINE_IDA(cper_esource_source_ids);
+
+struct cper_esource_ack {
+ void __iomem *addr;
+ u64 preserve;
+ u64 set;
+ u8 width;
+ bool present;
+};
+
+struct cper_esource {
+ struct device *dev;
+ void __iomem *status;
+ size_t status_len;
+
+ struct cper_esource_ack ack;
+
+ struct acpi_hest_generic *generic;
+ struct acpi_hest_generic_status *estatus;
+
+ bool sync;
+ int irq;
+
+ /* Serializes access while firmware and the OS share the status buffer. */
+ spinlock_t lock;
+};
+
+static void cper_esource_release_source_id(void *data)
+{
+ struct acpi_hest_generic *generic = data;
+
+ ida_free(&cper_esource_source_ids, generic->header.source_id);
+}
+
+static int cper_esource_init_pool(void)
+{
+ if (ghes_estatus_pool)
+ return 0;
+
+ return ghes_estatus_pool_init(1);
+}
+
+static int cper_esource_copy_status(struct cper_esource *ctx)
+{
+ memcpy_fromio(ctx->estatus, ctx->status, ctx->status_len);
+ return 0;
+}
+
+static void cper_esource_ack(struct cper_esource *ctx)
+{
+ u64 val;
+
+ if (!ctx->ack.present)
+ return;
+
+ if (ctx->ack.width == 64) {
+ val = readq(ctx->ack.addr);
+ val &= ctx->ack.preserve;
+ val |= ctx->ack.set;
+ writeq(val, ctx->ack.addr);
+ } else {
+ val = readl(ctx->ack.addr);
+ val &= (u32)ctx->ack.preserve;
+ val |= (u32)ctx->ack.set;
+ writel(val, ctx->ack.addr);
+ }
+}
+
+static void cper_esource_fatal(struct cper_esource *ctx)
+{
+ __ghes_print_estatus(KERN_EMERG, ctx->generic, ctx->estatus);
+ add_taint(TAINT_MACHINE_CHECK, LOCKDEP_STILL_OK);
+ panic("GHES: fatal firmware-first CPER record from %s\n",
+ dev_name(ctx->dev));
+}
+
+static void cper_esource_process(struct cper_esource *ctx)
+{
+ int sev;
+
+ guard(spinlock_irqsave)(&ctx->lock);
+
+ if (cper_esource_copy_status(ctx))
+ return;
+
+ sev = ghes_severity(ctx->estatus->error_severity);
+ if (sev >= GHES_SEV_PANIC)
+ cper_esource_fatal(ctx);
+
+ if (!ghes_estatus_cached(ctx->estatus) &&
+ ghes_print_estatus(NULL, ctx->generic, ctx->estatus))
+ ghes_estatus_cache_add(ctx->generic, ctx->estatus);
+
+ ghes_cper_handle_status(ctx->dev, ctx->generic, ctx->estatus, ctx->sync);
+ cper_esource_ack(ctx);
+}
+
+static irqreturn_t cper_esource_irq(int irq, void *data)
+{
+ struct cper_esource *ctx = data;
+
+ cper_esource_process(ctx);
+
+ return IRQ_HANDLED;
+}
+
+static int cper_esource_init_ack(struct platform_device *pdev,
+ struct cper_esource *ctx)
+{
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ size_t size;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ if (!res)
+ return 0;
+
+ ctx->ack.addr = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
+ if (IS_ERR(ctx->ack.addr))
+ return PTR_ERR(ctx->ack.addr);
+
+ size = resource_size(res);
+ switch (size) {
+ case 4:
+ ctx->ack.width = 32;
+ ctx->ack.preserve = ~0U;
+ break;
+ case 8:
+ ctx->ack.width = 64;
+ ctx->ack.preserve = ~0ULL;
+ break;
+ default:
+ return dev_err_probe(dev, -EINVAL,
+ "unsupported ack resource size %zu\n", size);
+ }
+
+ ctx->ack.set = BIT_ULL(0);
+ ctx->ack.present = true;
+ return 0;
+}
+
+static int cper_esource_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct cper_esource *ctx;
+ struct resource *res;
+ int source_id;
+ int rc;
+
+ ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ spin_lock_init(&ctx->lock);
+ ctx->dev = dev;
+ ctx->sync = device_property_read_bool(dev, "arm,sea-notify");
+
+ ctx->status = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(ctx->status))
+ return dev_err_probe(dev, PTR_ERR(ctx->status),
+ "failed to map status region\n");
+
+ ctx->status_len = resource_size(res);
+ if (!ctx->status_len)
+ return dev_err_probe(dev, -EINVAL, "status region has zero length\n");
+
+ rc = cper_esource_init_ack(pdev, ctx);
+ if (rc)
+ return rc;
+
+ rc = cper_esource_init_pool();
+ if (rc)
+ return rc;
+
+ ctx->estatus = devm_kzalloc(dev, ctx->status_len, GFP_KERNEL);
+ if (!ctx->estatus)
+ return -ENOMEM;
+
+ ctx->generic = devm_kzalloc(dev, sizeof(*ctx->generic), GFP_KERNEL);
+ if (!ctx->generic)
+ return -ENOMEM;
+
+ source_id = ida_alloc_min(&cper_esource_source_ids, 1, GFP_KERNEL);
+ if (source_id < 0)
+ return source_id;
+
+ ctx->generic->header.type = ACPI_HEST_TYPE_GENERIC_ERROR;
+ ctx->generic->header.source_id = source_id;
+
+ rc = devm_add_action_or_reset(dev, cper_esource_release_source_id,
+ ctx->generic);
+ if (rc)
+ return rc;
+
+ ctx->generic->notify.type = ctx->sync ?
+ ACPI_HEST_NOTIFY_SEA : ACPI_HEST_NOTIFY_EXTERNAL;
+ ctx->generic->error_block_length = ctx->status_len;
+
+ ctx->irq = platform_get_irq(pdev, 0);
+ if (ctx->irq < 0)
+ return ctx->irq;
+
+ rc = devm_request_threaded_irq(dev, ctx->irq, NULL, cper_esource_irq,
+ IRQF_ONESHOT,
+ dev_name(dev), ctx);
+ if (rc)
+ return dev_err_probe(dev, rc, "failed to request interrupt\n");
+
+ return 0;
+}
+
+static const struct of_device_id cper_esource_of_match[] = {
+ { .compatible = "arm,ras-cper" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, cper_esource_of_match);
+
+static struct platform_driver cper_esource_driver = {
+ .driver = {
+ .name = "cper-esource",
+ .of_match_table = cper_esource_of_match,
+ },
+ .probe = cper_esource_probe,
+};
+
+module_platform_driver(cper_esource_driver);
+
+MODULE_AUTHOR("Ahmed Tiba <ahmed.tiba@arm.com>");
+MODULE_DESCRIPTION("Firmware-first CPER provider");
+MODULE_LICENSE("GPL");
diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
index 511b95b50911..a78d4a773129 100644
--- a/include/acpi/ghes_cper.h
+++ b/include/acpi/ghes_cper.h
@@ -80,6 +80,14 @@ static inline bool is_hest_sync_notify(struct ghes *ghes)
return notify_type == ACPI_HEST_NOTIFY_SEA;
}
+static inline u32 cper_estatus_len(struct acpi_hest_generic_status *estatus)
+{
+ if (estatus->raw_data_length)
+ return estatus->raw_data_offset + estatus->raw_data_length;
+ else
+ return sizeof(*estatus) + estatus->data_length;
+}
+
struct ghes_vendor_record_entry {
struct work_struct work;
int error_severity;
@@ -108,6 +116,8 @@ int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
int ghes_estatus_cached(struct acpi_hest_generic_status *estatus);
void ghes_estatus_cache_add(struct acpi_hest_generic *generic,
struct acpi_hest_generic_status *estatus);
+int ghes_register_vendor_record_notifier(struct notifier_block *nb);
+void ghes_unregister_vendor_record_notifier(struct notifier_block *nb);
void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
int sev);
int ghes_severity(int severity);
--
2.43.0
^ permalink raw reply related
* Re: [PATCH 00/12] misc/syncobj: add /dev/syncobj device
From: Julian Orth @ 2026-05-18 12:02 UTC (permalink / raw)
To: Christian König
Cc: Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Sumit Semwal, Jonathan Corbet, Shuah Khan,
Arnd Bergmann, Greg Kroah-Hartman, dri-devel, linux-kernel,
linux-media, linaro-mm-sig, linux-doc, wayland-devel
In-Reply-To: <c6c91de9-a34b-4b50-a3c1-d42bf7631f8e@amd.com>
On Mon, May 18, 2026 at 1:58 PM Christian König
<christian.koenig@amd.com> wrote:
>
> On 5/16/26 13:06, Julian Orth wrote:
> > This series adds a new device /dev/syncobj that can be used to create
> > and manipulate DRM syncobjs. Previously, these operations required the
> > use of a DRM device and the device needed to support the DRIVER_SYNCOBJ
> > and DRIVER_SYNCOBJ_TIMELINE features.
> >
> > There are several issues with the existing API:
> >
> > - Syncobjs are the only explicit sync mechanism available on wayland.
> > Most compositors do not use GPU waits. Instead, they use the
> > DRM_IOCTL_SYNCOBJ_EVENTFD ioctl to perform a CPU wait. Being tied to
> > DRM devices means that compositors cannot consistently offer this
> > feature even though no device-specific logic is involved.
>
> Well the drm_syncobj is a container for device specific dma fences.
Not necessarily. The DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL ioctl attaches
some kind of dummy fence that is already signaled. I don't believe
this is device specific. That is also the path that llvmpipe would
use.
>
> What could be possible instead is to pass an eventfd into Wayland, but that is something userspace needs to decide.
>
> > - llvmpipe currently cannot offer syncobj interop because it does not
> > have access to a DRM device. This means that applications using
> > llvmpipe cannot present images before they have finished rendering,
> > despite llvmpipe using threaded rendering.
>
> Yeah, but that is completely intentional. You *CAN'T* use a dma_fence as completion event for llvmpipe rendering. See the kernel documentation on that.
>
> What could be possible is to use the drm_syncobjs functionality to wait before signal, but that has different semantics.
>
> Regards,
> Christian.
>
> > - Clients that do not use the Vulkan WSI need to manually probe /dev/dri
> > for devices that support the syncobj ioctls in order to use the
> > wayland syncobj protocol.
> > - Similarly, clients that want to use screen capture have no equivalent
> > to the WSI and are therefore forced into that path.
> > - Having to keep a DRM device open has potentially negative interactions
> > with GPU hotplug.
> > - Having to translate between syncobj FDs and handles is troublesome in
> > the compositor usecase since syncobjs come and go frequently and need
> > to be cleaned up when clients disconnect.
> >
> > /dev/syncobj solves these issues by providing all syncobj ioctls under a
> > consistent path that is not tied to any DRM device. It also operates
> > directly on file descriptors instead of syncobj handles.
> >
> > The series starts with a number of small refactorings in drm_syncobj.c
> > to make its functionality available outside of the file and without the
> > need for drm_file/handle pairs.
> >
> > The last commit adds the /dev/syncobj module. I've added it as a misc
> > device but maybe this should instead live somewhere under gpu/drm.
> >
> > An application using the new interface can be found at [1].
> >
> > [1]: https://github.com/mahkoh/jay/pull/947
> >
> > ---
> > Julian Orth (12):
> > drm/syncobj: add drm_syncobj_from_fd
> > drm/syncobj: add drm_syncobj_fence_lookup
> > drm/syncobj: make drm_syncobj_array_wait_timeout public
> > drm/syncobj: add drm_syncobj_register_eventfd
> > drm/syncobj: have transfer functions accept drm_syncobj directly
> > drm/syncobj: add drm_syncobj_transfer
> > drm/syncobj: add drm_syncobj_timeline_signal
> > drm/syncobj: add drm_syncobj_query
> > drm/syncobj: fix resource leak in drm_syncobj_import_sync_file_fence
> > drm/syncobj: add drm_syncobj_import_sync_file
> > drm/syncobj: add drm_syncobj_export_sync_file
> > misc/syncobj: add new device
> >
> > Documentation/userspace-api/ioctl/ioctl-number.rst | 1 +
> > drivers/gpu/drm/drm_syncobj.c | 374 ++++++++++++++-----
> > drivers/misc/Kconfig | 10 +
> > drivers/misc/Makefile | 1 +
> > drivers/misc/syncobj.c | 404 +++++++++++++++++++++
> > include/drm/drm_syncobj.h | 21 ++
> > include/uapi/linux/syncobj.h | 75 ++++
> > 7 files changed, 795 insertions(+), 91 deletions(-)
> > ---
> > base-commit: 6916d5703ddf9a38f1f6c2cc793381a24ee914c6
> > change-id: 20260516-jorth-syncobj-d4d374c8c61b
> >
> > Best regards,
> > --
> > Julian Orth <ju.orth@gmail.com>
> >
>
^ permalink raw reply
* Re: [PATCH 12/12] misc/syncobj: add new device
From: Christian König @ 2026-05-18 12:06 UTC (permalink / raw)
To: Julian Orth, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann,
David Airlie, Simona Vetter, Sumit Semwal, Jonathan Corbet,
Shuah Khan, Arnd Bergmann, Greg Kroah-Hartman
Cc: dri-devel, linux-kernel, linux-media, linaro-mm-sig, linux-doc,
wayland-devel
In-Reply-To: <20260516-jorth-syncobj-v1-12-88ede9d98a81@gmail.com>
On 5/16/26 13:06, Julian Orth wrote:
> This device makes the DRM_IOCTL_SYNCOBJ_* ioctls available via a
> dedicated device. This allows applications to use syncobjs without
> having to open device nodes in /dev/dri, on systems that don't have any
> such nodes, or on systems whose devices don't support the
> DRIVER_SYNCOBJ_TIMELINE feature.
>
> Wayland uses syncobjs as its buffer synchronization mechanism. Most
> compositors use the DRM_IOCTL_SYNCOBJ_EVENTFD ioctl to perform a pure
> CPU wait for syncobj point. DRM devices are not involved in this process
> except insofar that a DRM device needs to be used to access the ioctl.
>
> Similarly, a software-rendered client might perform rendering on a
> dedicated thread and use the wayland syncobj protocol to submit frames
> before they finish rendering. Again, this does not involve DRM devices
> except insofar ... as above.
That use case is invalid.
Usually drm_syncobj can only be filled with dma_fence objects and it is impossible to create one of those for software rendering.
What could be used is the drm_syncobj wait before signal functionality, but that usually requires special handling on the Wayland/Compositor side which as far as I can see doesn't make sense here either.
So the justification to use this for software rendering is very weak. Either I'm missing something or that is not going to fly at all.
Regards,
Christian.
>
> As an added benefit, this device removes the need to translate between
> file descriptors and handles.
>
> Signed-off-by: Julian Orth <ju.orth@gmail.com>
> ---
> Documentation/userspace-api/ioctl/ioctl-number.rst | 1 +
> drivers/misc/Kconfig | 10 +
> drivers/misc/Makefile | 1 +
> drivers/misc/syncobj.c | 404 +++++++++++++++++++++
> include/uapi/linux/syncobj.h | 75 ++++
> 5 files changed, 491 insertions(+)
>
> diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
> index 331223761fff..5e140ae5735e 100644
> --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> @@ -395,6 +395,7 @@ Code Seq# Include File Comments
> <mailto:michael.klein@puffin.lb.shuttle.de>
> 0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver
> 0xCD 01 linux/reiserfs_fs.h Dead since 6.13
> +0xCD 00-0F uapi/linux/syncobj.h
> 0xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices
> 0xCF 02 fs/smb/client/cifs_ioctl.h
> 0xDD 00-3F ZFCP device driver see drivers/s390/scsi/
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index 00683bf06258..c1e7749bd356 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -644,6 +644,16 @@ config MCHP_LAN966X_PCI
> - lan966x-miim (MDIO_MSCC_MIIM)
> - lan966x-switch (LAN966X_SWITCH)
>
> +config SYNCOBJ_DEV
> + tristate "DRM syncobj device (/dev/syncobj)"
> + depends on DRM
> + help
> + Creates a /dev/syncobj device node that provides DRM synchronization
> + objects (syncobjs) without requiring a DRM device.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called syncobj.
> +
> source "drivers/misc/c2port/Kconfig"
> source "drivers/misc/eeprom/Kconfig"
> source "drivers/misc/cb710/Kconfig"
> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> index b32a2597d246..9e5deb1d0d76 100644
> --- a/drivers/misc/Makefile
> +++ b/drivers/misc/Makefile
> @@ -75,3 +75,4 @@ obj-$(CONFIG_MCHP_LAN966X_PCI) += lan966x-pci.o
> obj-y += keba/
> obj-y += amd-sbi/
> obj-$(CONFIG_MISC_RP1) += rp1/
> +obj-$(CONFIG_SYNCOBJ_DEV) += syncobj.o
> diff --git a/drivers/misc/syncobj.c b/drivers/misc/syncobj.c
> new file mode 100644
> index 000000000000..11ef46ddfeef
> --- /dev/null
> +++ b/drivers/misc/syncobj.c
> @@ -0,0 +1,404 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * syncobj.c - Standalone device for syncobj manipulation.
> + *
> + * Copyright (C) 2026 Julian Orth <ju.orth@gmail.com>
> + */
> +
> +#include <linux/fdtable.h>
> +#include <linux/miscdevice.h>
> +#include <linux/module.h>
> +#include <linux/uaccess.h>
> +#include <drm/drm_syncobj.h>
> +#include <drm/drm_utils.h>
> +#include <uapi/drm/drm.h>
> +#include <uapi/linux/syncobj.h>
> +
> +static int syncobj_array_find(void __user *user_fds, u32 count,
> + struct drm_syncobj ***syncobjs_out)
> +{
> + u32 i;
> + s32 *fds;
> + struct drm_syncobj **syncobjs;
> + int ret;
> +
> + fds = kmalloc_array(count, sizeof(*fds), GFP_KERNEL);
> + if (!fds)
> + return -ENOMEM;
> +
> + if (copy_from_user(fds, user_fds, sizeof(s32) * count)) {
> + ret = -EFAULT;
> + goto err_free_fds;
> + }
> +
> + syncobjs = kmalloc_array(count, sizeof(*syncobjs), GFP_KERNEL);
> + if (!syncobjs) {
> + ret = -ENOMEM;
> + goto err_free_fds;
> + }
> +
> + for (i = 0; i < count; i++) {
> + syncobjs[i] = drm_syncobj_from_fd(fds[i]);
> + if (!syncobjs[i]) {
> + ret = -EBADF;
> + goto err_put_syncobjs;
> + }
> + }
> +
> + kfree(fds);
> + *syncobjs_out = syncobjs;
> + return 0;
> +
> +err_put_syncobjs:
> + while (i-- > 0)
> + drm_syncobj_put(syncobjs[i]);
> + kfree(syncobjs);
> +err_free_fds:
> + kfree(fds);
> + return ret;
> +}
> +
> +static void syncobj_array_free(struct drm_syncobj **syncobjs, u32 count)
> +{
> + u32 i;
> +
> + for (i = 0; i < count; i++)
> + drm_syncobj_put(syncobjs[i]);
> + kfree(syncobjs);
> +}
> +
> +static int syncobj_ioctl_create(void __user *argp)
> +{
> + struct syncobj_create_args args;
> + struct drm_syncobj *syncobj;
> + int fd, ret;
> +
> + if (copy_from_user(&args, argp, sizeof(args)))
> + return -EFAULT;
> +
> + if (args.flags & ~SYNCOBJ_CREATE_SIGNALED)
> + return -EINVAL;
> +
> + static_assert(SYNCOBJ_CREATE_SIGNALED == DRM_SYNCOBJ_CREATE_SIGNALED);
> +
> + ret = drm_syncobj_create(&syncobj, args.flags, NULL);
> + if (ret)
> + return ret;
> +
> + ret = drm_syncobj_get_fd(syncobj, &fd);
> + drm_syncobj_put(syncobj);
> + if (ret)
> + return ret;
> +
> + args.fd = fd;
> + if (copy_to_user(argp, &args, sizeof(args))) {
> + close_fd(fd);
> + return -EFAULT;
> + }
> +
> + return 0;
> +}
> +
> +static int syncobj_ioctl_wait(void __user *argp)
> +{
> + struct syncobj_wait_args args;
> + struct drm_syncobj **syncobjs;
> + signed long timeout;
> + u32 first = ~0;
> + ktime_t t, *tp = NULL;
> + int ret;
> +
> + if (copy_from_user(&args, argp, sizeof(args)))
> + return -EFAULT;
> +
> + if (args.flags & ~(SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
> + SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
> + SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE |
> + SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE))
> + return -EINVAL;
> +
> + static_assert(SYNCOBJ_WAIT_FLAGS_WAIT_ALL == DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL);
> + static_assert(SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT == DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT);
> + static_assert(SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE == DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE);
> + static_assert(SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE == DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE);
> +
> + if (args.pad)
> + return -EINVAL;
> +
> + if (args.count == 0)
> + return 0;
> +
> + ret = syncobj_array_find(u64_to_user_ptr(args.fds),
> + args.count, &syncobjs);
> + if (ret < 0)
> + return ret;
> +
> + if (args.flags & SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE) {
> + t = ns_to_ktime(args.deadline_nsec);
> + tp = &t;
> + }
> +
> + timeout = drm_timeout_abs_to_jiffies(args.timeout_nsec);
> + timeout = drm_syncobj_array_wait_timeout(syncobjs,
> + u64_to_user_ptr(args.points),
> + args.count,
> + args.flags,
> + timeout, &first, tp);
> +
> + syncobj_array_free(syncobjs, args.count);
> +
> + if (timeout < 0)
> + return timeout;
> +
> + args.first_signaled = first;
> + if (copy_to_user(argp, &args, sizeof(args)))
> + return -EFAULT;
> +
> + return 0;
> +}
> +
> +static int syncobj_ioctl_reset(void __user *argp)
> +{
> + struct syncobj_array_args args;
> + struct drm_syncobj **syncobjs;
> + u32 i;
> + int ret;
> +
> + if (copy_from_user(&args, argp, sizeof(args)))
> + return -EFAULT;
> +
> + if (args.flags)
> + return -EINVAL;
> +
> + if (args.points)
> + return -EINVAL;
> +
> + if (args.count == 0)
> + return -EINVAL;
> +
> + ret = syncobj_array_find(u64_to_user_ptr(args.fds),
> + args.count, &syncobjs);
> + if (ret < 0)
> + return ret;
> +
> + for (i = 0; i < args.count; i++)
> + drm_syncobj_replace_fence(syncobjs[i], NULL);
> +
> + syncobj_array_free(syncobjs, args.count);
> + return 0;
> +}
> +
> +static int syncobj_ioctl_signal(void __user *argp)
> +{
> + struct syncobj_array_args args;
> + struct drm_syncobj **syncobjs;
> + int ret;
> +
> + if (copy_from_user(&args, argp, sizeof(args)))
> + return -EFAULT;
> +
> + if (args.flags)
> + return -EINVAL;
> +
> + if (args.count == 0)
> + return -EINVAL;
> +
> + ret = syncobj_array_find(u64_to_user_ptr(args.fds),
> + args.count, &syncobjs);
> + if (ret < 0)
> + return ret;
> +
> + ret = drm_syncobj_timeline_signal(syncobjs, args.points, args.count);
> +
> + syncobj_array_free(syncobjs, args.count);
> + return ret;
> +}
> +
> +static int syncobj_ioctl_query(void __user *argp)
> +{
> + struct syncobj_array_args args;
> + struct drm_syncobj **syncobjs;
> + int ret;
> +
> + if (copy_from_user(&args, argp, sizeof(args)))
> + return -EFAULT;
> +
> + if (args.flags & ~SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED)
> + return -EINVAL;
> +
> + static_assert(SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED == DRM_SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED);
> +
> + if (args.count == 0)
> + return -EINVAL;
> +
> + ret = syncobj_array_find(u64_to_user_ptr(args.fds),
> + args.count, &syncobjs);
> + if (ret < 0)
> + return ret;
> +
> + ret = drm_syncobj_query(syncobjs, args.points, args.count, args.flags);
> +
> + syncobj_array_free(syncobjs, args.count);
> + return ret;
> +}
> +
> +static int syncobj_ioctl_transfer(void __user *argp)
> +{
> + struct syncobj_transfer_args args;
> + struct drm_syncobj *src, *dst;
> + int ret;
> +
> + if (copy_from_user(&args, argp, sizeof(args)))
> + return -EFAULT;
> +
> + if (args.pad)
> + return -EINVAL;
> +
> + if (args.flags & ~SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT)
> + return -EINVAL;
> +
> + static_assert(SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT == DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT);
> +
> + src = drm_syncobj_from_fd(args.src_fd);
> + if (!src)
> + return -EBADF;
> +
> + dst = drm_syncobj_from_fd(args.dst_fd);
> + if (!dst) {
> + drm_syncobj_put(src);
> + return -EBADF;
> + }
> +
> + ret = drm_syncobj_transfer(src, args.src_point,
> + dst, args.dst_point, args.flags);
> +
> + drm_syncobj_put(dst);
> + drm_syncobj_put(src);
> +
> + return ret;
> +}
> +
> +static int syncobj_ioctl_eventfd(void __user *argp)
> +{
> + struct syncobj_eventfd_args args;
> + struct drm_syncobj *syncobj;
> + int ret;
> +
> + if (copy_from_user(&args, argp, sizeof(args)))
> + return -EFAULT;
> +
> + if (args.flags & ~SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)
> + return -EINVAL;
> +
> + static_assert(SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE == DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE);
> +
> + if (args.pad)
> + return -EINVAL;
> +
> + syncobj = drm_syncobj_from_fd(args.syncobj_fd);
> + if (!syncobj)
> + return -EBADF;
> +
> + ret = drm_syncobj_register_eventfd(syncobj, args.eventfd,
> + args.point, args.flags);
> +
> + drm_syncobj_put(syncobj);
> +
> + return ret;
> +}
> +
> +static int syncobj_ioctl_export_sync_file(void __user *argp)
> +{
> + struct syncobj_sync_file_args args;
> + struct drm_syncobj *syncobj;
> + int ret;
> +
> + if (copy_from_user(&args, argp, sizeof(args)))
> + return -EFAULT;
> +
> + syncobj = drm_syncobj_from_fd(args.syncobj_fd);
> + if (!syncobj)
> + return -EBADF;
> +
> + ret = drm_syncobj_export_sync_file(syncobj, args.point,
> + &args.sync_file_fd);
> + drm_syncobj_put(syncobj);
> + if (ret)
> + return ret;
> +
> + if (copy_to_user(argp, &args, sizeof(args))) {
> + close_fd(args.sync_file_fd);
> + return -EFAULT;
> + }
> +
> + return 0;
> +}
> +
> +static int syncobj_ioctl_import_sync_file(void __user *argp)
> +{
> + struct syncobj_sync_file_args args;
> + struct drm_syncobj *syncobj;
> + int ret;
> +
> + if (copy_from_user(&args, argp, sizeof(args)))
> + return -EFAULT;
> +
> + syncobj = drm_syncobj_from_fd(args.syncobj_fd);
> + if (!syncobj)
> + return -EBADF;
> +
> + ret = drm_syncobj_import_sync_file(syncobj, args.sync_file_fd,
> + args.point);
> +
> + drm_syncobj_put(syncobj);
> +
> + return ret;
> +}
> +
> +static long syncobj_dev_ioctl(struct file *file, unsigned int cmd,
> + unsigned long arg)
> +{
> + void __user *argp = (void __user *)arg;
> +
> + switch (cmd) {
> + case SYNCOBJ_IOC_CREATE:
> + return syncobj_ioctl_create(argp);
> + case SYNCOBJ_IOC_WAIT:
> + return syncobj_ioctl_wait(argp);
> + case SYNCOBJ_IOC_RESET:
> + return syncobj_ioctl_reset(argp);
> + case SYNCOBJ_IOC_SIGNAL:
> + return syncobj_ioctl_signal(argp);
> + case SYNCOBJ_IOC_QUERY:
> + return syncobj_ioctl_query(argp);
> + case SYNCOBJ_IOC_TRANSFER:
> + return syncobj_ioctl_transfer(argp);
> + case SYNCOBJ_IOC_EVENTFD:
> + return syncobj_ioctl_eventfd(argp);
> + case SYNCOBJ_IOC_EXPORT_SYNC_FILE:
> + return syncobj_ioctl_export_sync_file(argp);
> + case SYNCOBJ_IOC_IMPORT_SYNC_FILE:
> + return syncobj_ioctl_import_sync_file(argp);
> + default:
> + return -ENOIOCTLCMD;
> + }
> +}
> +
> +static const struct file_operations syncobj_dev_fops = {
> + .owner = THIS_MODULE,
> + .unlocked_ioctl = syncobj_dev_ioctl,
> + .compat_ioctl = compat_ptr_ioctl,
> +};
> +
> +static struct miscdevice syncobj_misc = {
> + .minor = MISC_DYNAMIC_MINOR,
> + .name = "syncobj",
> + .fops = &syncobj_dev_fops,
> + .mode = 0666,
> +};
> +
> +module_misc_device(syncobj_misc);
> +
> +MODULE_AUTHOR("Julian Orth");
> +MODULE_DESCRIPTION("DRM syncobj device");
> +MODULE_LICENSE("GPL");
> diff --git a/include/uapi/linux/syncobj.h b/include/uapi/linux/syncobj.h
> new file mode 100644
> index 000000000000..c4068fbd5773
> --- /dev/null
> +++ b/include/uapi/linux/syncobj.h
> @@ -0,0 +1,75 @@
> +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
> +#ifndef _UAPI_LINUX_SYNCOBJ_H_
> +#define _UAPI_LINUX_SYNCOBJ_H_
> +
> +#include <linux/ioctl.h>
> +#include <linux/types.h>
> +
> +#define SYNCOBJ_CREATE_SIGNALED (1 << 0)
> +
> +#define SYNCOBJ_WAIT_FLAGS_WAIT_ALL (1 << 0)
> +#define SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT (1 << 1)
> +#define SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE (1 << 2)
> +#define SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE (1 << 3)
> +
> +#define SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED (1 << 0)
> +
> +struct syncobj_create_args {
> + __s32 fd;
> + __u32 flags;
> +};
> +
> +struct syncobj_wait_args {
> + __u64 fds;
> + __u64 points;
> + __s64 timeout_nsec;
> + __u32 count;
> + __u32 flags;
> + __u32 first_signaled;
> + __u32 pad;
> + __u64 deadline_nsec;
> +};
> +
> +struct syncobj_array_args {
> + __u64 fds;
> + __u64 points;
> + __u32 count;
> + __u32 flags;
> +};
> +
> +struct syncobj_transfer_args {
> + __s32 src_fd;
> + __s32 dst_fd;
> + __u64 src_point;
> + __u64 dst_point;
> + __u32 flags;
> + __u32 pad;
> +};
> +
> +struct syncobj_eventfd_args {
> + __s32 syncobj_fd;
> + __s32 eventfd;
> + __u64 point;
> + __u32 flags;
> + __u32 pad;
> +};
> +
> +struct syncobj_sync_file_args {
> + __s32 syncobj_fd;
> + __s32 sync_file_fd;
> + __u64 point;
> +};
> +
> +#define SYNCOBJ_IOC_BASE 0xCD
> +
> +#define SYNCOBJ_IOC_CREATE _IOWR(SYNCOBJ_IOC_BASE, 0, struct syncobj_create_args)
> +#define SYNCOBJ_IOC_WAIT _IOWR(SYNCOBJ_IOC_BASE, 1, struct syncobj_wait_args)
> +#define SYNCOBJ_IOC_RESET _IOW(SYNCOBJ_IOC_BASE, 2, struct syncobj_array_args)
> +#define SYNCOBJ_IOC_SIGNAL _IOW(SYNCOBJ_IOC_BASE, 3, struct syncobj_array_args)
> +#define SYNCOBJ_IOC_QUERY _IOW(SYNCOBJ_IOC_BASE, 4, struct syncobj_array_args)
> +#define SYNCOBJ_IOC_TRANSFER _IOW(SYNCOBJ_IOC_BASE, 5, struct syncobj_transfer_args)
> +#define SYNCOBJ_IOC_EVENTFD _IOW(SYNCOBJ_IOC_BASE, 6, struct syncobj_eventfd_args)
> +#define SYNCOBJ_IOC_EXPORT_SYNC_FILE _IOWR(SYNCOBJ_IOC_BASE, 7, struct syncobj_sync_file_args)
> +#define SYNCOBJ_IOC_IMPORT_SYNC_FILE _IOW(SYNCOBJ_IOC_BASE, 8, struct syncobj_sync_file_args)
> +
> +#endif /* _UAPI_LINUX_SYNCOBJ_H_ */
>
^ permalink raw reply
* Re: [Linaro-mm-sig] Re: [PATCH RFC 2/5] dma-heap: charge dma-buf memory via explicit memcg
From: Albert Esteve @ 2026-05-18 12:06 UTC (permalink / raw)
To: Christian König
Cc: Barry Song, T.J. Mercier, Tejun Heo, Johannes Weiner,
Michal Koutný, Jonathan Corbet, Shuah Khan, Sumit Semwal,
Michal Hocko, Roman Gushchin, Shakeel Butt, Muchun Song,
Andrew Morton, Benjamin Gaignard, Brian Starkey, John Stultz,
Christian Brauner, Paul Moore, James Morris, Serge E. Hallyn,
Stephen Smalley, Ondrej Mosnacek, Shuah Khan, cgroups, linux-doc,
linux-kernel, linux-media, dri-, linaro-mm-sig, linux-mm,
linux-security-module, selinux, linux-kselftest, mripard,
echanude
In-Reply-To: <cb84c2ee-9de1-4565-b2e0-60984721228f@amd.com>
On Mon, May 18, 2026 at 9:34 AM Christian König
<christian.koenig@amd.com> wrote:
>
> On 5/16/26 11:19, Barry Song wrote:
> > On Thu, May 14, 2026 at 12:35 AM T.J. Mercier <tjmercier@google.com> wrote:
> > [...]
> >>>> I have a question about this part. Albert I guess you are interested
> >>>> only in accounting dmabuf-heap allocations, or do you expect to add
> >>>> __GFP_ACCOUNT or mem_cgroup_charge_dmabuf calls to other
> >>>> non-dmabuf-heap exporters?
> >>>
> >>> We're scoping this to dma-buf heaps for now. CMA heaps and the dmem
> >>> controller are on the radar for follow-up/parallel work (there will be
> >>> dragons and will surely need discussion). For DRM and V4L2 the
> >>> long-term intent is migration to heaps, which would make direct
> >>> accounting on those paths unnecessary.
> >>
> >> Ah I see. GEM buffers exported to dmabufs are what I had in mind. I
> >> guess this would only leave the odd non-DRM driver with the need to
> >> add their own accounting calls, which I don't expect would be a big
> >> problem.
> >>
> >
> > sounds like we still have a long way to go to correctly account for
> > various v4l2, drm, GEM, CMA, etc. In patch 1, the charging is done in
> > dma_buf_export(), so I guess it covers all dma-buf types except
> > dma_heap, but the problem is that it has no remote charging support at
> > all?
>
> No, just the other way around
>
> DMA-buf heaps can be handled here because we know that it is pure system memory and nothing special so memcg always applies.
>
> dma_buf_export() on the other hand handles tons of different use cases, ranging from buffer accounted to dmem, over special resources which aren't even memory all the way to buffers which can migrate from dmem to memcg and back during their lifetime.
>
> >>> udmabufs are already
> >>> memcg-charged, so adding a separate MEMCG_DMABUF would double count.
> >>> Are there any other exporters you had in mind that would benefit from
> >>> this approach?
>
> Well apart from DMA-buf memfd_create() is one of the things which as broken our neck in the past a couple of times.
>
> But thinking more about it what if instead of making this DMA-buf heaps specific what if we have a general cgroups function which allows to change accounting of a buffer referenced by a file descriptor to a different process?
>
> That would cover not only the DMA-buf heaps use case, but also all other DMA-buf with dmem and whatever we come up in the future as well.
I removed a draft adding an ioctl for charge transfer from the series
before sending because I wanted to focus on the charge_pid_fd approach
and keep things simple, deferring the recharge path to a follow-up
depending on feedback.
The main difference between my removed draft and what you're
describing, iiuc, is scope and layer: my draft was an explicit ioctl
on the dma-buf fd that the consumer calls to claim the charge (see
below), while you seem to be suggesting a more general kernel-internal
function that could work across buffer types and cgroup controllers,
so not necessarily userspace-initiated? A kernel-internal function
will need a way to identify the target process, which sounds similar
to the binder-backed approach from TJ [1]. For everything else, the
receiver still needs to declare itself, which the ioctl accomplishes.
```
# When an app imports a daemon-allocated buffer, it can transfer the
charge to itself:
int buf_fd = receive_dmabuf_from_daemon();
ioctl(buf_fd, DMA_BUF_IOCTL_XFER_CHARGE); /* charge now attributed to
apps's cgroup */
```
[1] https://lore.kernel.org/cgroups/20230109213809.418135-1-tjmercier@google.com/
>
> The only drawback I can see is that DMA-buf heap allocations would be temporarily accounted to the memory allocation daemon, but I don't think that this would be a problem.
The main reasons we moved away from TJ's transfer-based approach
toward `charge_pid_fd` are: avoid the transient charge window on the
daemon's cgroup; and to decouple from Binder, allowing any allocator
to use it.
Technically, both approaches could coexist, though. Of the three
scenarios TJ described:
- Scenario 2 is directly addressed by charge_pid_fd approach without
any transient charge on the daemon at the cost of one extra field in
the heap ioctl uAPI struct.
- Scenario 3 can be handled by the charge transfer function without
changes to SurfaceFlinger. The app or dequeueBuffer claims the charge
for itself or the app, respectively (depending on whether we include a
pid_fd field in the transfer ioctl). It also covers non-heap
exporters. The con in both variants is the transient charge window on
the daemon.
Both approaches shift the responsibility for correct charging
attribution to userspace: first, 'charge_pid_fd` on the allocator's
side, and the transfer charge on the consumer's side.
Deciding on one, the other or both depends on how much we value
avoiding transient attribution, and how much we need a non-heap
generic solution. With the XFER_CHARGE we can cover both. Thus, the
`charge_pid_fd` approach in this RFC can be seen as a
performance/strictness optimisation, eliminating transient charges to
the daemon at the cost of a permanent uAPI addition to the heap ioctl
struct, but not strictly required for correctness. On the other hand,
if we agree on the end goal of migrating other exporters to use
dma-buf heaps, and scenario 3 is addressed by adding the app's pid_fd
to SurfaceFlinger, then `charge_pid_fd` alone is a coherent/sufficient
approach despite the uAPI change.
>
> Regards,
> Christian.
>
> >
> > Thanks
> > Barry
>
^ permalink raw reply
* Re: [PATCH 12/12] misc/syncobj: add new device
From: Julian Orth @ 2026-05-18 12:10 UTC (permalink / raw)
To: Christian König
Cc: Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Sumit Semwal, Jonathan Corbet, Shuah Khan,
Arnd Bergmann, Greg Kroah-Hartman, dri-devel, linux-kernel,
linux-media, linaro-mm-sig, linux-doc, wayland-devel
In-Reply-To: <8602a990-e557-45e3-8b3a-f9e6aaa00e0d@amd.com>
On Mon, May 18, 2026 at 2:06 PM Christian König
<christian.koenig@amd.com> wrote:
>
> On 5/16/26 13:06, Julian Orth wrote:
> > This device makes the DRM_IOCTL_SYNCOBJ_* ioctls available via a
> > dedicated device. This allows applications to use syncobjs without
> > having to open device nodes in /dev/dri, on systems that don't have any
> > such nodes, or on systems whose devices don't support the
> > DRIVER_SYNCOBJ_TIMELINE feature.
> >
> > Wayland uses syncobjs as its buffer synchronization mechanism. Most
> > compositors use the DRM_IOCTL_SYNCOBJ_EVENTFD ioctl to perform a pure
> > CPU wait for syncobj point. DRM devices are not involved in this process
> > except insofar that a DRM device needs to be used to access the ioctl.
> >
> > Similarly, a software-rendered client might perform rendering on a
> > dedicated thread and use the wayland syncobj protocol to submit frames
> > before they finish rendering. Again, this does not involve DRM devices
> > except insofar ... as above.
>
> That use case is invalid.
>
> Usually drm_syncobj can only be filled with dma_fence objects and it is impossible to create one of those for software rendering.
That is simply not true. As I wrote above,
DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL can be used with software rendering.
>
> What could be used is the drm_syncobj wait before signal functionality, but that usually requires special handling on the Wayland/Compositor side which as far as I can see doesn't make sense here either.
Commit (to wayland) before submit (rendering work) is fully supported
by the wayland syncobj protocol. No work needs to be done on the
wayland side. In fact, everything that this series enables can already
be done today by opening random /dev/dri nodes until you find one that
supports the syncobj timeline ioctls. This series just makes it
easier.
>
> So the justification to use this for software rendering is very weak. Either I'm missing something or that is not going to fly at all.
>
> Regards,
> Christian.
>
> >
> > As an added benefit, this device removes the need to translate between
> > file descriptors and handles.
> >
> > Signed-off-by: Julian Orth <ju.orth@gmail.com>
> > ---
> > Documentation/userspace-api/ioctl/ioctl-number.rst | 1 +
> > drivers/misc/Kconfig | 10 +
> > drivers/misc/Makefile | 1 +
> > drivers/misc/syncobj.c | 404 +++++++++++++++++++++
> > include/uapi/linux/syncobj.h | 75 ++++
> > 5 files changed, 491 insertions(+)
> >
> > diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
> > index 331223761fff..5e140ae5735e 100644
> > --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> > +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> > @@ -395,6 +395,7 @@ Code Seq# Include File Comments
> > <mailto:michael.klein@puffin.lb.shuttle.de>
> > 0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver
> > 0xCD 01 linux/reiserfs_fs.h Dead since 6.13
> > +0xCD 00-0F uapi/linux/syncobj.h
> > 0xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices
> > 0xCF 02 fs/smb/client/cifs_ioctl.h
> > 0xDD 00-3F ZFCP device driver see drivers/s390/scsi/
> > diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> > index 00683bf06258..c1e7749bd356 100644
> > --- a/drivers/misc/Kconfig
> > +++ b/drivers/misc/Kconfig
> > @@ -644,6 +644,16 @@ config MCHP_LAN966X_PCI
> > - lan966x-miim (MDIO_MSCC_MIIM)
> > - lan966x-switch (LAN966X_SWITCH)
> >
> > +config SYNCOBJ_DEV
> > + tristate "DRM syncobj device (/dev/syncobj)"
> > + depends on DRM
> > + help
> > + Creates a /dev/syncobj device node that provides DRM synchronization
> > + objects (syncobjs) without requiring a DRM device.
> > +
> > + To compile this driver as a module, choose M here: the module
> > + will be called syncobj.
> > +
> > source "drivers/misc/c2port/Kconfig"
> > source "drivers/misc/eeprom/Kconfig"
> > source "drivers/misc/cb710/Kconfig"
> > diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> > index b32a2597d246..9e5deb1d0d76 100644
> > --- a/drivers/misc/Makefile
> > +++ b/drivers/misc/Makefile
> > @@ -75,3 +75,4 @@ obj-$(CONFIG_MCHP_LAN966X_PCI) += lan966x-pci.o
> > obj-y += keba/
> > obj-y += amd-sbi/
> > obj-$(CONFIG_MISC_RP1) += rp1/
> > +obj-$(CONFIG_SYNCOBJ_DEV) += syncobj.o
> > diff --git a/drivers/misc/syncobj.c b/drivers/misc/syncobj.c
> > new file mode 100644
> > index 000000000000..11ef46ddfeef
> > --- /dev/null
> > +++ b/drivers/misc/syncobj.c
> > @@ -0,0 +1,404 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * syncobj.c - Standalone device for syncobj manipulation.
> > + *
> > + * Copyright (C) 2026 Julian Orth <ju.orth@gmail.com>
> > + */
> > +
> > +#include <linux/fdtable.h>
> > +#include <linux/miscdevice.h>
> > +#include <linux/module.h>
> > +#include <linux/uaccess.h>
> > +#include <drm/drm_syncobj.h>
> > +#include <drm/drm_utils.h>
> > +#include <uapi/drm/drm.h>
> > +#include <uapi/linux/syncobj.h>
> > +
> > +static int syncobj_array_find(void __user *user_fds, u32 count,
> > + struct drm_syncobj ***syncobjs_out)
> > +{
> > + u32 i;
> > + s32 *fds;
> > + struct drm_syncobj **syncobjs;
> > + int ret;
> > +
> > + fds = kmalloc_array(count, sizeof(*fds), GFP_KERNEL);
> > + if (!fds)
> > + return -ENOMEM;
> > +
> > + if (copy_from_user(fds, user_fds, sizeof(s32) * count)) {
> > + ret = -EFAULT;
> > + goto err_free_fds;
> > + }
> > +
> > + syncobjs = kmalloc_array(count, sizeof(*syncobjs), GFP_KERNEL);
> > + if (!syncobjs) {
> > + ret = -ENOMEM;
> > + goto err_free_fds;
> > + }
> > +
> > + for (i = 0; i < count; i++) {
> > + syncobjs[i] = drm_syncobj_from_fd(fds[i]);
> > + if (!syncobjs[i]) {
> > + ret = -EBADF;
> > + goto err_put_syncobjs;
> > + }
> > + }
> > +
> > + kfree(fds);
> > + *syncobjs_out = syncobjs;
> > + return 0;
> > +
> > +err_put_syncobjs:
> > + while (i-- > 0)
> > + drm_syncobj_put(syncobjs[i]);
> > + kfree(syncobjs);
> > +err_free_fds:
> > + kfree(fds);
> > + return ret;
> > +}
> > +
> > +static void syncobj_array_free(struct drm_syncobj **syncobjs, u32 count)
> > +{
> > + u32 i;
> > +
> > + for (i = 0; i < count; i++)
> > + drm_syncobj_put(syncobjs[i]);
> > + kfree(syncobjs);
> > +}
> > +
> > +static int syncobj_ioctl_create(void __user *argp)
> > +{
> > + struct syncobj_create_args args;
> > + struct drm_syncobj *syncobj;
> > + int fd, ret;
> > +
> > + if (copy_from_user(&args, argp, sizeof(args)))
> > + return -EFAULT;
> > +
> > + if (args.flags & ~SYNCOBJ_CREATE_SIGNALED)
> > + return -EINVAL;
> > +
> > + static_assert(SYNCOBJ_CREATE_SIGNALED == DRM_SYNCOBJ_CREATE_SIGNALED);
> > +
> > + ret = drm_syncobj_create(&syncobj, args.flags, NULL);
> > + if (ret)
> > + return ret;
> > +
> > + ret = drm_syncobj_get_fd(syncobj, &fd);
> > + drm_syncobj_put(syncobj);
> > + if (ret)
> > + return ret;
> > +
> > + args.fd = fd;
> > + if (copy_to_user(argp, &args, sizeof(args))) {
> > + close_fd(fd);
> > + return -EFAULT;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int syncobj_ioctl_wait(void __user *argp)
> > +{
> > + struct syncobj_wait_args args;
> > + struct drm_syncobj **syncobjs;
> > + signed long timeout;
> > + u32 first = ~0;
> > + ktime_t t, *tp = NULL;
> > + int ret;
> > +
> > + if (copy_from_user(&args, argp, sizeof(args)))
> > + return -EFAULT;
> > +
> > + if (args.flags & ~(SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
> > + SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
> > + SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE |
> > + SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE))
> > + return -EINVAL;
> > +
> > + static_assert(SYNCOBJ_WAIT_FLAGS_WAIT_ALL == DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL);
> > + static_assert(SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT == DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT);
> > + static_assert(SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE == DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE);
> > + static_assert(SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE == DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE);
> > +
> > + if (args.pad)
> > + return -EINVAL;
> > +
> > + if (args.count == 0)
> > + return 0;
> > +
> > + ret = syncobj_array_find(u64_to_user_ptr(args.fds),
> > + args.count, &syncobjs);
> > + if (ret < 0)
> > + return ret;
> > +
> > + if (args.flags & SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE) {
> > + t = ns_to_ktime(args.deadline_nsec);
> > + tp = &t;
> > + }
> > +
> > + timeout = drm_timeout_abs_to_jiffies(args.timeout_nsec);
> > + timeout = drm_syncobj_array_wait_timeout(syncobjs,
> > + u64_to_user_ptr(args.points),
> > + args.count,
> > + args.flags,
> > + timeout, &first, tp);
> > +
> > + syncobj_array_free(syncobjs, args.count);
> > +
> > + if (timeout < 0)
> > + return timeout;
> > +
> > + args.first_signaled = first;
> > + if (copy_to_user(argp, &args, sizeof(args)))
> > + return -EFAULT;
> > +
> > + return 0;
> > +}
> > +
> > +static int syncobj_ioctl_reset(void __user *argp)
> > +{
> > + struct syncobj_array_args args;
> > + struct drm_syncobj **syncobjs;
> > + u32 i;
> > + int ret;
> > +
> > + if (copy_from_user(&args, argp, sizeof(args)))
> > + return -EFAULT;
> > +
> > + if (args.flags)
> > + return -EINVAL;
> > +
> > + if (args.points)
> > + return -EINVAL;
> > +
> > + if (args.count == 0)
> > + return -EINVAL;
> > +
> > + ret = syncobj_array_find(u64_to_user_ptr(args.fds),
> > + args.count, &syncobjs);
> > + if (ret < 0)
> > + return ret;
> > +
> > + for (i = 0; i < args.count; i++)
> > + drm_syncobj_replace_fence(syncobjs[i], NULL);
> > +
> > + syncobj_array_free(syncobjs, args.count);
> > + return 0;
> > +}
> > +
> > +static int syncobj_ioctl_signal(void __user *argp)
> > +{
> > + struct syncobj_array_args args;
> > + struct drm_syncobj **syncobjs;
> > + int ret;
> > +
> > + if (copy_from_user(&args, argp, sizeof(args)))
> > + return -EFAULT;
> > +
> > + if (args.flags)
> > + return -EINVAL;
> > +
> > + if (args.count == 0)
> > + return -EINVAL;
> > +
> > + ret = syncobj_array_find(u64_to_user_ptr(args.fds),
> > + args.count, &syncobjs);
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = drm_syncobj_timeline_signal(syncobjs, args.points, args.count);
> > +
> > + syncobj_array_free(syncobjs, args.count);
> > + return ret;
> > +}
> > +
> > +static int syncobj_ioctl_query(void __user *argp)
> > +{
> > + struct syncobj_array_args args;
> > + struct drm_syncobj **syncobjs;
> > + int ret;
> > +
> > + if (copy_from_user(&args, argp, sizeof(args)))
> > + return -EFAULT;
> > +
> > + if (args.flags & ~SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED)
> > + return -EINVAL;
> > +
> > + static_assert(SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED == DRM_SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED);
> > +
> > + if (args.count == 0)
> > + return -EINVAL;
> > +
> > + ret = syncobj_array_find(u64_to_user_ptr(args.fds),
> > + args.count, &syncobjs);
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = drm_syncobj_query(syncobjs, args.points, args.count, args.flags);
> > +
> > + syncobj_array_free(syncobjs, args.count);
> > + return ret;
> > +}
> > +
> > +static int syncobj_ioctl_transfer(void __user *argp)
> > +{
> > + struct syncobj_transfer_args args;
> > + struct drm_syncobj *src, *dst;
> > + int ret;
> > +
> > + if (copy_from_user(&args, argp, sizeof(args)))
> > + return -EFAULT;
> > +
> > + if (args.pad)
> > + return -EINVAL;
> > +
> > + if (args.flags & ~SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT)
> > + return -EINVAL;
> > +
> > + static_assert(SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT == DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT);
> > +
> > + src = drm_syncobj_from_fd(args.src_fd);
> > + if (!src)
> > + return -EBADF;
> > +
> > + dst = drm_syncobj_from_fd(args.dst_fd);
> > + if (!dst) {
> > + drm_syncobj_put(src);
> > + return -EBADF;
> > + }
> > +
> > + ret = drm_syncobj_transfer(src, args.src_point,
> > + dst, args.dst_point, args.flags);
> > +
> > + drm_syncobj_put(dst);
> > + drm_syncobj_put(src);
> > +
> > + return ret;
> > +}
> > +
> > +static int syncobj_ioctl_eventfd(void __user *argp)
> > +{
> > + struct syncobj_eventfd_args args;
> > + struct drm_syncobj *syncobj;
> > + int ret;
> > +
> > + if (copy_from_user(&args, argp, sizeof(args)))
> > + return -EFAULT;
> > +
> > + if (args.flags & ~SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)
> > + return -EINVAL;
> > +
> > + static_assert(SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE == DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE);
> > +
> > + if (args.pad)
> > + return -EINVAL;
> > +
> > + syncobj = drm_syncobj_from_fd(args.syncobj_fd);
> > + if (!syncobj)
> > + return -EBADF;
> > +
> > + ret = drm_syncobj_register_eventfd(syncobj, args.eventfd,
> > + args.point, args.flags);
> > +
> > + drm_syncobj_put(syncobj);
> > +
> > + return ret;
> > +}
> > +
> > +static int syncobj_ioctl_export_sync_file(void __user *argp)
> > +{
> > + struct syncobj_sync_file_args args;
> > + struct drm_syncobj *syncobj;
> > + int ret;
> > +
> > + if (copy_from_user(&args, argp, sizeof(args)))
> > + return -EFAULT;
> > +
> > + syncobj = drm_syncobj_from_fd(args.syncobj_fd);
> > + if (!syncobj)
> > + return -EBADF;
> > +
> > + ret = drm_syncobj_export_sync_file(syncobj, args.point,
> > + &args.sync_file_fd);
> > + drm_syncobj_put(syncobj);
> > + if (ret)
> > + return ret;
> > +
> > + if (copy_to_user(argp, &args, sizeof(args))) {
> > + close_fd(args.sync_file_fd);
> > + return -EFAULT;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int syncobj_ioctl_import_sync_file(void __user *argp)
> > +{
> > + struct syncobj_sync_file_args args;
> > + struct drm_syncobj *syncobj;
> > + int ret;
> > +
> > + if (copy_from_user(&args, argp, sizeof(args)))
> > + return -EFAULT;
> > +
> > + syncobj = drm_syncobj_from_fd(args.syncobj_fd);
> > + if (!syncobj)
> > + return -EBADF;
> > +
> > + ret = drm_syncobj_import_sync_file(syncobj, args.sync_file_fd,
> > + args.point);
> > +
> > + drm_syncobj_put(syncobj);
> > +
> > + return ret;
> > +}
> > +
> > +static long syncobj_dev_ioctl(struct file *file, unsigned int cmd,
> > + unsigned long arg)
> > +{
> > + void __user *argp = (void __user *)arg;
> > +
> > + switch (cmd) {
> > + case SYNCOBJ_IOC_CREATE:
> > + return syncobj_ioctl_create(argp);
> > + case SYNCOBJ_IOC_WAIT:
> > + return syncobj_ioctl_wait(argp);
> > + case SYNCOBJ_IOC_RESET:
> > + return syncobj_ioctl_reset(argp);
> > + case SYNCOBJ_IOC_SIGNAL:
> > + return syncobj_ioctl_signal(argp);
> > + case SYNCOBJ_IOC_QUERY:
> > + return syncobj_ioctl_query(argp);
> > + case SYNCOBJ_IOC_TRANSFER:
> > + return syncobj_ioctl_transfer(argp);
> > + case SYNCOBJ_IOC_EVENTFD:
> > + return syncobj_ioctl_eventfd(argp);
> > + case SYNCOBJ_IOC_EXPORT_SYNC_FILE:
> > + return syncobj_ioctl_export_sync_file(argp);
> > + case SYNCOBJ_IOC_IMPORT_SYNC_FILE:
> > + return syncobj_ioctl_import_sync_file(argp);
> > + default:
> > + return -ENOIOCTLCMD;
> > + }
> > +}
> > +
> > +static const struct file_operations syncobj_dev_fops = {
> > + .owner = THIS_MODULE,
> > + .unlocked_ioctl = syncobj_dev_ioctl,
> > + .compat_ioctl = compat_ptr_ioctl,
> > +};
> > +
> > +static struct miscdevice syncobj_misc = {
> > + .minor = MISC_DYNAMIC_MINOR,
> > + .name = "syncobj",
> > + .fops = &syncobj_dev_fops,
> > + .mode = 0666,
> > +};
> > +
> > +module_misc_device(syncobj_misc);
> > +
> > +MODULE_AUTHOR("Julian Orth");
> > +MODULE_DESCRIPTION("DRM syncobj device");
> > +MODULE_LICENSE("GPL");
> > diff --git a/include/uapi/linux/syncobj.h b/include/uapi/linux/syncobj.h
> > new file mode 100644
> > index 000000000000..c4068fbd5773
> > --- /dev/null
> > +++ b/include/uapi/linux/syncobj.h
> > @@ -0,0 +1,75 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
> > +#ifndef _UAPI_LINUX_SYNCOBJ_H_
> > +#define _UAPI_LINUX_SYNCOBJ_H_
> > +
> > +#include <linux/ioctl.h>
> > +#include <linux/types.h>
> > +
> > +#define SYNCOBJ_CREATE_SIGNALED (1 << 0)
> > +
> > +#define SYNCOBJ_WAIT_FLAGS_WAIT_ALL (1 << 0)
> > +#define SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT (1 << 1)
> > +#define SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE (1 << 2)
> > +#define SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE (1 << 3)
> > +
> > +#define SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED (1 << 0)
> > +
> > +struct syncobj_create_args {
> > + __s32 fd;
> > + __u32 flags;
> > +};
> > +
> > +struct syncobj_wait_args {
> > + __u64 fds;
> > + __u64 points;
> > + __s64 timeout_nsec;
> > + __u32 count;
> > + __u32 flags;
> > + __u32 first_signaled;
> > + __u32 pad;
> > + __u64 deadline_nsec;
> > +};
> > +
> > +struct syncobj_array_args {
> > + __u64 fds;
> > + __u64 points;
> > + __u32 count;
> > + __u32 flags;
> > +};
> > +
> > +struct syncobj_transfer_args {
> > + __s32 src_fd;
> > + __s32 dst_fd;
> > + __u64 src_point;
> > + __u64 dst_point;
> > + __u32 flags;
> > + __u32 pad;
> > +};
> > +
> > +struct syncobj_eventfd_args {
> > + __s32 syncobj_fd;
> > + __s32 eventfd;
> > + __u64 point;
> > + __u32 flags;
> > + __u32 pad;
> > +};
> > +
> > +struct syncobj_sync_file_args {
> > + __s32 syncobj_fd;
> > + __s32 sync_file_fd;
> > + __u64 point;
> > +};
> > +
> > +#define SYNCOBJ_IOC_BASE 0xCD
> > +
> > +#define SYNCOBJ_IOC_CREATE _IOWR(SYNCOBJ_IOC_BASE, 0, struct syncobj_create_args)
> > +#define SYNCOBJ_IOC_WAIT _IOWR(SYNCOBJ_IOC_BASE, 1, struct syncobj_wait_args)
> > +#define SYNCOBJ_IOC_RESET _IOW(SYNCOBJ_IOC_BASE, 2, struct syncobj_array_args)
> > +#define SYNCOBJ_IOC_SIGNAL _IOW(SYNCOBJ_IOC_BASE, 3, struct syncobj_array_args)
> > +#define SYNCOBJ_IOC_QUERY _IOW(SYNCOBJ_IOC_BASE, 4, struct syncobj_array_args)
> > +#define SYNCOBJ_IOC_TRANSFER _IOW(SYNCOBJ_IOC_BASE, 5, struct syncobj_transfer_args)
> > +#define SYNCOBJ_IOC_EVENTFD _IOW(SYNCOBJ_IOC_BASE, 6, struct syncobj_eventfd_args)
> > +#define SYNCOBJ_IOC_EXPORT_SYNC_FILE _IOWR(SYNCOBJ_IOC_BASE, 7, struct syncobj_sync_file_args)
> > +#define SYNCOBJ_IOC_IMPORT_SYNC_FILE _IOW(SYNCOBJ_IOC_BASE, 8, struct syncobj_sync_file_args)
> > +
> > +#endif /* _UAPI_LINUX_SYNCOBJ_H_ */
> >
>
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