=======================================Peak Tops Limiter (PTL) sysfs Interface======================================= Overview--------The Peak Tops Limiter (PTL) sysfs interface enables users to control andconfigure the PTL feature for each GPU individually.  All PTL-relatedsysfs files are located under `/sys/class/drm/cardX/device/ptl/`, where`X` is the GPU index.  Through these files, users can enable or disablePTL, set preferred data formats, and query supported formats for each GPU. PTL sysfs files----------------The following files are available under `/sys/class/drm/cardX/device/ptl/`: - `ptl_enable`- `ptl_format`- `ptl_supported_formats` PTL Enable/Disable------------------File: `ptl_enable`Type: Read/Write (rw) Read: Returns the current PTL status as a string: `enabled` if PTLis active, or `disabled` if inactive. Write: - Write `1` or `enabled` to enable PTL- Write `0` or `disabled` to disable PTL Examples::     # Query PTL status    cat /sys/class/drm/card1/device/ptl/ptl_enable    # Output: enabled     # Enable PTL    sudo bash -c "echo 1 > /sys/class/drm/card1/device/ptl/ptl_enable"     # Disable PTL    sudo bash -c "echo 0 > /sys/class/drm/card1/device/ptl/ptl_enable" PTL Format (Preferred Data Formats)-----------------------------------File: `ptl_format`Type: Read/Write (rw) Read: Returns the two preferred formats, e.g. `I8,F32`. Write: Accepts two formats separated by a comma, e.g. `I8,F32`. - Both formats must be supported and different.- If an invalid format is provided (not supported, or both formats are the  same), the driver will return "write error: Invalid argument". Examples::     # Query PTL formats    cat /sys/class/drm/card1/device/ptl/ptl_format    # Output: I8,F32     # Set PTL formats    sudo bash -c "echo I8,F32 > /sys/class/drm/card1/device/ptl/ptl_format" Supported Formats-----------------File: `ptl_supported_formats`Type: Read-only (r) Read: Returns a comma-separated list of supported formats, e.g.`I8,F16,BF16,F32,F64`. Example::     # Check supported formats    cat /sys/class/drm/card1/device/ptl/ptl_supported_formats    # Output: I8,F16,BF16,F32,F64 Behavioral Notes----------------- PTL formats can only be set when PTL is enabled.- If PTL is disabled, `ptl_format` returns `N/A`.- Only two formats can be set at a time, and they must be from the supported set and different..- All commands support per-GPU targeting.- Root permission is required to enable/disable PTL or change formats.- If the hardware does not support PTL, the PTL sysfs directory will not  be created. Implementation--------------The PTL sysfs nodes are implemented in `drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c`.