From 2bc6b218717b9d08f466f88209251d54bc09b207 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Tue, 22 Sep 2026 19:14:30 +0100 Subject: arm64/boot: Disable trapping of PMZR_EL0 writes to EL2 __init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2. PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a write from EL0 reaches the trap and takes the host down without a panic message. Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9 bits. Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9") Cc: stable@vger.kernel.org Signed-off-by: Fuad Tabba Reviewed-by: Anshuman Khandual Reviewed-by: Oliver Upton Signed-off-by: Will Deacon --- Documentation/gpu/amdgpu/thermal.rst | 170 +++++++++++++++++++++++++++++++++++ 1 file changed, 170 insertions(+) create mode 100644 Documentation/gpu/amdgpu/thermal.rst (limited to 'Documentation/gpu/amdgpu/thermal.rst') diff --git a/Documentation/gpu/amdgpu/thermal.rst b/Documentation/gpu/amdgpu/thermal.rst new file mode 100644 index 000000000..1768a106a --- /dev/null +++ b/Documentation/gpu/amdgpu/thermal.rst @@ -0,0 +1,170 @@ +=========================================== + GPU Power/Thermal Controls and Monitoring +=========================================== + +HWMON Interfaces +================ + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: hwmon + +GPU sysfs Power State Interfaces +================================ + +GPU power controls are exposed via sysfs files. + +power_dpm_state +--------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: power_dpm_state + +power_dpm_force_performance_level +--------------------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: power_dpm_force_performance_level + +pp_table +-------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: pp_table + +pp_od_clk_voltage +----------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: pp_od_clk_voltage + +pp_dpm_* +-------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: pp_dpm_sclk pp_dpm_mclk pp_dpm_socclk pp_dpm_fclk pp_dpm_dcefclk pp_dpm_pcie + +pp_power_profile_mode +--------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: pp_power_profile_mode + +pm_policy +--------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: pm_policy + +\*_busy_percent +--------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: gpu_busy_percent + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: mem_busy_percent + +gpu_metrics +----------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: gpu_metrics + +fan_curve +--------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: fan_curve + +acoustic_limit_rpm_threshold +---------------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: acoustic_limit_rpm_threshold + +acoustic_target_rpm_threshold +----------------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: acoustic_target_rpm_threshold + +fan_target_temperature +---------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: fan_target_temperature + +fan_minimum_pwm +--------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: fan_minimum_pwm + +fan_zero_rpm_enable +---------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: fan_zero_rpm_enable + +fan_zero_rpm_stop_temperature +----------------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: fan_zero_rpm_stop_temperature + +GFXOFF +====== + +GFXOFF is a feature found in most recent GPUs that saves power at runtime. The +card's RLC (RunList Controller) firmware powers off the gfx engine +dynamically when there is no workload on gfx or compute pipes. GFXOFF is on by +default on supported GPUs. + +Userspace can interact with GFXOFF through a debugfs interface (all values in +`uint32_t`, unless otherwise noted): + +``amdgpu_gfxoff`` +----------------- + +Use it to enable/disable GFXOFF, and to check if it's current enabled/disabled:: + + $ xxd -l1 -p /sys/kernel/debug/dri/0/amdgpu_gfxoff + 01 + +- Write 0 to disable it, and 1 to enable it. +- Read 0 means it's disabled, 1 it's enabled. + +If it's enabled, that means that the GPU is free to enter into GFXOFF mode as +needed. Disabled means that it will never enter GFXOFF mode. + +``amdgpu_gfxoff_status`` +------------------------ + +Read it to check current GFXOFF's status of a GPU:: + + $ xxd -l1 -p /sys/kernel/debug/dri/0/amdgpu_gfxoff_status + 02 + +- 0: GPU is in GFXOFF state, the gfx engine is powered down. +- 1: Transition out of GFXOFF state +- 2: Not in GFXOFF state +- 3: Transition into GFXOFF state + +If GFXOFF is enabled, the value will be transitioning around [0, 3], always +getting into 0 when possible. When it's disabled, it's always at 2. Returns +``-EINVAL`` if it's not supported. + +``amdgpu_gfxoff_count`` +----------------------- + +Read it to get the total GFXOFF entry count at the time of query since system +power-up. The value is an `uint64_t` type, however, due to firmware limitations, +it can currently overflow as an `uint32_t`. *Only supported in vangogh* + +``amdgpu_gfxoff_residency`` +--------------------------- + +Write 1 to amdgpu_gfxoff_residency to start logging, and 0 to stop. Read it to +get average GFXOFF residency % multiplied by 100 during the last logging +interval. E.g. a value of 7854 means 78.54% of the time in the last logging +interval the GPU was in GFXOFF mode. *Only supported in vangogh* -- cgit v1.3.1