From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- 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