From f4cdf7ca9a1fdcca413157df19753f388a5a224e Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 19 Aug 2026 10:09:22 -0700 Subject: Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ... --- Documentation/gpu/amdgpu/process-isolation.rst | 60 ++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 Documentation/gpu/amdgpu/process-isolation.rst (limited to 'Documentation/gpu/amdgpu/process-isolation.rst') diff --git a/Documentation/gpu/amdgpu/process-isolation.rst b/Documentation/gpu/amdgpu/process-isolation.rst new file mode 100644 index 000000000..03c4288aa --- /dev/null +++ b/Documentation/gpu/amdgpu/process-isolation.rst @@ -0,0 +1,60 @@ +.. _amdgpu-process-isolation: +.. SPDX-License-Identifier: GPL-2.0 + +========================= + AMDGPU Process Isolation +========================= + +The AMDGPU driver includes a feature that enables automatic process isolation on the graphics engine. This feature serializes access to the graphics engine and adds a cleaner shader which clears the Local Data Store (LDS) and General Purpose Registers (GPRs) between jobs. All processes using the GPU, including both graphics and compute workloads, are serialized when this feature is enabled. On GPUs that support partitionable graphics engines, this feature can be enabled on a per-partition basis. + +In addition, there is an interface to manually run the cleaner shader when the use of the GPU is complete. This may be preferable in some use cases, such as a single-user system where the login manager triggers the cleaner shader when the user logs out. + +Process Isolation +================= + +The `run_cleaner_shader` and `enforce_isolation` sysfs interfaces allow users to manually execute the cleaner shader and control the process isolation feature, respectively. + +Partition Handling +------------------ + +The `enforce_isolation` file in sysfs can be used to enable process isolation and automatic shader cleanup between processes. On GPUs that support graphics engine partitioning, this can be enabled per partition. The partition and its current setting (0 disabled, 1 enabled) can be read from sysfs. On GPUs that do not support graphics engine partitioning, only a single partition will be present. Writing 1 to the partition position enables enforce isolation, writing 0 disables it. + +Example of enabling enforce isolation on a GPU with multiple partitions: + +.. code-block:: console + + $ echo 1 0 1 0 > /sys/class/drm/card0/device/enforce_isolation + $ cat /sys/class/drm/card0/device/enforce_isolation + 1 0 1 0 + +The output indicates that enforce isolation is enabled on zeroth and second partition and disabled on first and third partition. + +For devices with a single partition or those that do not support partitions, there will be only one element: + +.. code-block:: console + + $ echo 1 > /sys/class/drm/card0/device/enforce_isolation + $ cat /sys/class/drm/card0/device/enforce_isolation + 1 + +Cleaner Shader Execution +======================== + +The driver can trigger a cleaner shader to clean up the LDS and GPR state on the graphics engine. When process isolation is enabled, this happens automatically between processes. In addition, there is a sysfs file to manually trigger cleaner shader execution. + +To manually trigger the execution of the cleaner shader, write `0` to the `run_cleaner_shader` sysfs file: + +.. code-block:: console + + $ echo 0 > /sys/class/drm/card0/device/run_cleaner_shader + +For multi-partition devices, you can specify the partition index when triggering the cleaner shader: + +.. code-block:: console + + $ echo 0 > /sys/class/drm/card0/device/run_cleaner_shader # For partition 0 + $ echo 1 > /sys/class/drm/card0/device/run_cleaner_shader # For partition 1 + $ echo 2 > /sys/class/drm/card0/device/run_cleaner_shader # For partition 2 + # ... and so on for each partition + +This command initiates the cleaner shader, which will run and complete before any new tasks are scheduled on the GPU. -- cgit v1.3.1