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| author | Yo-Jung Leo Lin (AMD) <Leo.Lin@amd.com> | 2025-12-12 10:59:17 +0300 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2026-01-06 00:59:58 +0300 |
| commit | 5946dbe1c802efef3b12a4eecab1471f725f4ca9 (patch) | |
| tree | 7b8e7d4ac03d34885ff46a0b4e1ff895ab2a1738 | |
| parent | 19ba61ac06d2a4f1e58f92879b54a998ab23b4b1 (diff) | |
| download | linux-5946dbe1c802efef3b12a4eecab1471f725f4ca9.tar.xz | |
Documentation/amdgpu: Add UMA carveout details
Add documentation for the uma/carveout_options and uma/carveout
attributes in sysfs
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Yo-Jung Leo Lin (AMD) <Leo.Lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| -rw-r--r-- | Documentation/gpu/amdgpu/driver-misc.rst | 26 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 29 |
2 files changed, 55 insertions, 0 deletions
diff --git a/Documentation/gpu/amdgpu/driver-misc.rst b/Documentation/gpu/amdgpu/driver-misc.rst index 25b0c857816e..e1a964c3add2 100644 --- a/Documentation/gpu/amdgpu/driver-misc.rst +++ b/Documentation/gpu/amdgpu/driver-misc.rst @@ -128,3 +128,29 @@ smartshift_bias .. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c :doc: smartshift_bias + +UMA Carveout +============ + +Some versions of Atom ROM expose available options for the VRAM carveout sizes, +and allow changes to the carveout size via the ATCS function code 0xA on supported +BIOS implementations. + +For those platforms, users can use the following files under uma/ to set the +carveout size, in a way similar to what Windows users can do in the "Tuning" +tab in AMD Adrenalin. + +Note that for BIOS implementations that don't support this, these files will not +be created at all. + +uma/carveout_options +-------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_device.c + :doc: uma/carveout_options + +uma/carveout +-------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_device.c + :doc: uma/carveout diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index 96842b041372..6378926f1aeb 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -382,6 +382,24 @@ static const struct attribute_group amdgpu_board_attrs_group = { .is_visible = amdgpu_board_attrs_is_visible }; +/** + * DOC: uma/carveout_options + * + * This is a read-only file that lists all available UMA allocation + * options and their corresponding indices. Example output:: + * + * $ cat uma/carveout_options + * 0: Minimum (512 MB) + * 1: (1 GB) + * 2: (2 GB) + * 3: (4 GB) + * 4: (6 GB) + * 5: (8 GB) + * 6: (12 GB) + * 7: Medium (16 GB) + * 8: (24 GB) + * 9: High (32 GB) + */ static ssize_t carveout_options_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -414,6 +432,17 @@ static ssize_t carveout_options_show(struct device *dev, } static DEVICE_ATTR_RO(carveout_options); +/** + * DOC: uma/carveout + * + * This file is both readable and writable. When read, it shows the + * index of the current setting. Writing a valid index to this file + * allows users to change the UMA carveout size to the selected option + * on the next boot. + * + * The available options and their corresponding indices can be read + * from the uma/carveout_options file. + */ static ssize_t carveout_show(struct device *dev, struct device_attribute *attr, char *buf) |