Add documentation for the uma_carveout_options and uma_carveout attributes in sysfs
Signed-off-by: Yo-Jung Leo Lin (AMD) <[email protected]> --- Documentation/gpu/amdgpu/driver-misc.rst | 26 ++++++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 55 insertions(+) diff --git a/Documentation/gpu/amdgpu/driver-misc.rst b/Documentation/gpu/amdgpu/driver-misc.rst index 25b0c857816e..afefab4fa0ac 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 file 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_acpi.c + :doc: uma_carveout_options + +uma_carveout +-------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c + :doc: uma_carveout diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c index b9378f34eb79..10cc6bf28a0f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c @@ -1248,6 +1248,24 @@ int amdgpu_acpi_get_mem_info(struct amdgpu_device *adev, int xcc_id, return -ENOENT; } +/** + * 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 (0 GB) + * 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 uma_carveout_options_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -1269,6 +1287,17 @@ static ssize_t uma_carveout_options_show(struct device *dev, } static DEVICE_ATTR_RO(uma_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 uma_carveout_show(struct device *dev, struct device_attribute *attr, char *buf) -- 2.43.0
