Add per-GPU sysfs files under /sys/class/drm/cardX/device/ptl to control the Peak Tops Limiter (PTL) feature. Exposes ptl_enable (enable/disable PTL), ptl_format (set/query preferred formats), and ptl_supported_formats (list supported formats) Example usage ------------- Query PTL status: `cat /sys/class/drm/card1/device/ptl/ptl_enable` 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"` Set PTL preferred formats: `sudo bash -c "echo I8,F32 > /sys/class/drm/card1/device/ptl/ptl_format"` Query supported formats: `cat /sys/class/drm/card1/device/ptl/ptl_supported_formats` v3 changes: * move N/A to previous format in format show(Alex) * fix format check for format store(Alex) * drop the ptl declarations into amdgpu_ptl.h(Alex) v2 changes: * add usage commands in commit info (Alex) * move amdgpu_ptl_fmt into kgd_kfd_interface.h (Alex) Signed-off-by: Perry Yuan <perry.yuan@amd.com> Reviewed-by: Yifan Zhang <yifan1.zhang@amd.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>