[Patch v4 0/2] Add support for _TFP and change throttle pctg

[Patch v4 0/2] Add support for _TFP and change throttle pctg

[Sumit Gupta]

This patch set adds two improvements to get a finer control over the
impact of thermal throttling on performance.

 1) Patch 1: Adds support to read "Thermal fast Sampling Period (_TFP)"
    ACPI object and use it over "Thermal Sampling Period (_TSP)" for
    Passive cooling if both are present.

 2) Patch 2: Adds support to reduce the CPUFREQ reduction percentage
    and not always cause throttling in steps of "20%" for Tegra241 SoC.

Both patches can be applied independently.

---
v3[3] -> 4:
- Patch 2: move ARM code from generic to new file 'thermal_cpufreq.c'.
         : get 'cpufreq_thermal_pctg' value for Tegra241 from new file. 
         : move dummy/null function to 'acpi.h'.

v2[2] -> v3:
- Patch1: rebased on top of linux-next.
- Patch2: use __read_mostly for the cpufreq_thermal_* variables.
        : add static to new function acpi_thermal_cpufreq_config_nvidia.
        : add null function if CONFIG_HAVE_ARM_SMCCC_DISCOVERY undefined
        : removed redundant parenthesis.

v1[1] -> v2:
- Patch1: add ACPI spec section info in commit description and rebased.
- Patch2: add info about hardware in the commit description.
        : switched CPUFREQ THERMAL tuning macros to static variables.
        : update the tunings for Tegra241 SoC only using soc_id check.

Jeff Brasen (1):
  ACPI: thermal: Add Thermal fast Sampling Period (_TFP) support

Srikar Srimath Tirumala (1):
  ACPI: processor: reduce CPUFREQ thermal reduction pctg for Tegra241

 drivers/acpi/arm64/Makefile          |  1 +
 drivers/acpi/arm64/thermal_cpufreq.c | 20 ++++++++++++++++
 drivers/acpi/processor_thermal.c     | 35 +++++++++++++++++++++++++---
 drivers/acpi/thermal.c               | 17 +++++++++-----
 include/linux/acpi.h                 |  9 +++++++
 5 files changed, 73 insertions(+), 9 deletions(-)
 create mode 100644 drivers/acpi/arm64/thermal_cpufreq.c

[3] https://lore.kernel.org/linux-acpi/20231006153612.5851-1-sumitg@nvidia.com/ 
[2] https://lore.kernel.org/lkml/20230913164659.9345-1-sumitg@nvidia.com/
[1] https://lore.kernel.org/lkml/20230817093011.1378-1-sumitg@nvidia.com/

-- 
2.17.1

[Patch v4 1/2] ACPI: thermal: Add Thermal fast Sampling Period (_TFP) support

[Sumit Gupta]

From: Jeff Brasen <jbrasen@nvidia.com>

Add support of "Thermal fast Sampling Period (_TFP)" for Passive cooling.
As per [1], _TFP overrides the "Thermal Sampling Period (_TSP)" if both
are present in a Thermal zone.

[1] ACPI Specification 6.4 - section 11.4.17. _TFP (Thermal fast Sampling
    Period)"

Signed-off-by: Jeff Brasen <jbrasen@nvidia.com>
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
---
 drivers/acpi/thermal.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 356d577689ff..e360aeebd249 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -90,7 +90,7 @@ struct acpi_thermal_passive {
 	struct acpi_thermal_trip trip;
 	unsigned long tc1;
 	unsigned long tc2;
-	unsigned long tsp;
+	unsigned long passive_delay;
 };
 
 struct acpi_thermal_active {
@@ -404,11 +404,16 @@ static bool passive_trip_params_init(struct acpi_thermal *tz)
 
 	tz->trips.passive.tc2 = tmp;
 
-	status = acpi_evaluate_integer(tz->device->handle, "_TSP", NULL, &tmp);
-	if (ACPI_FAILURE(status))
-		return false;
+	status = acpi_evaluate_integer(tz->device->handle, "_TFP", NULL, &tmp);
+	if (ACPI_FAILURE(status)) {
+		status = acpi_evaluate_integer(tz->device->handle, "_TSP", NULL, &tmp);
+		if (ACPI_FAILURE(status))
+			return false;
 
-	tz->trips.passive.tsp = tmp;
+		tz->trips.passive.passive_delay = tmp * 100;
+	} else {
+		tz->trips.passive.passive_delay = tmp;
+	}
 
 	return true;
 }
@@ -904,7 +909,7 @@ static int acpi_thermal_add(struct acpi_device *device)
 
 	acpi_trip = &tz->trips.passive.trip;
 	if (acpi_thermal_trip_valid(acpi_trip)) {
-		passive_delay = tz->trips.passive.tsp * 100;
+		passive_delay = tz->trips.passive.passive_delay;
 
 		trip->type = THERMAL_TRIP_PASSIVE;
 		trip->temperature = acpi_thermal_temp(tz, acpi_trip->temp_dk);
-- 
2.17.1

[Patch v4 2/2] ACPI: processor: reduce CPUFREQ thermal reduction pctg for Tegra241

[Sumit Gupta]

From: Srikar Srimath Tirumala <srikars@nvidia.com>

Current implementation of processor_thermal performs software throttling
in fixed steps of "20%" which can be too coarse for some platforms.
We observed some performance gain after reducing the throttle percentage.
Change the CPUFREQ thermal reduction percentage and maximum thermal steps
to be configurable. Also, update the default values of both for Nvidia
Tegra241 (Grace) SoC. The thermal reduction percentage is reduced to "5%"
and accordingly the maximum number of thermal steps are increased as they
are derived from the reduction percentage.

Signed-off-by: Srikar Srimath Tirumala <srikars@nvidia.com>
Co-developed-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
---
 drivers/acpi/arm64/Makefile          |  1 +
 drivers/acpi/arm64/thermal_cpufreq.c | 20 ++++++++++++++++
 drivers/acpi/processor_thermal.c     | 35 +++++++++++++++++++++++++---
 include/linux/acpi.h                 |  9 +++++++
 4 files changed, 62 insertions(+), 3 deletions(-)
 create mode 100644 drivers/acpi/arm64/thermal_cpufreq.c

diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
index 143debc1ba4a..3f181d8156cc 100644
--- a/drivers/acpi/arm64/Makefile
+++ b/drivers/acpi/arm64/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_ACPI_GTDT) 	+= gtdt.o
 obj-$(CONFIG_ACPI_APMT) 	+= apmt.o
 obj-$(CONFIG_ARM_AMBA)		+= amba.o
 obj-y				+= dma.o init.o
+obj-$(CONFIG_ACPI)		+= thermal_cpufreq.o
diff --git a/drivers/acpi/arm64/thermal_cpufreq.c b/drivers/acpi/arm64/thermal_cpufreq.c
new file mode 100644
index 000000000000..de834fb013e7
--- /dev/null
+++ b/drivers/acpi/arm64/thermal_cpufreq.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/acpi.h>
+
+#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
+#define SMCCC_SOC_ID_T241      0x036b0241
+
+int acpi_thermal_cpufreq_pctg(void)
+{
+	s32 soc_id = arm_smccc_get_soc_id_version();
+
+	/*
+	 * Check JEP106 code for NVIDIA Tegra241 chip (036b:0241) and
+	 * reduce the CPUFREQ Thermal reduction percentage to 5%.
+	 */
+	if (soc_id == SMCCC_SOC_ID_T241)
+		return 5;
+
+	return 0;
+}
+#endif
diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
index b7c6287eccca..52f316e4e260 100644
--- a/drivers/acpi/processor_thermal.c
+++ b/drivers/acpi/processor_thermal.c
@@ -26,7 +26,16 @@
  */
 
 #define CPUFREQ_THERMAL_MIN_STEP 0
-#define CPUFREQ_THERMAL_MAX_STEP 3
+
+static int cpufreq_thermal_max_step __read_mostly = 3;
+
+/*
+ * Minimum throttle percentage for processor_thermal cooling device.
+ * The processor_thermal driver uses it to calculate the percentage amount by
+ * which cpu frequency must be reduced for each cooling state. This is also used
+ * to calculate the maximum number of throttling steps or cooling states.
+ */
+static int cpufreq_thermal_pctg __read_mostly = 20;
 
 static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
 
@@ -71,7 +80,7 @@ static int cpufreq_get_max_state(unsigned int cpu)
 	if (!cpu_has_cpufreq(cpu))
 		return 0;
 
-	return CPUFREQ_THERMAL_MAX_STEP;
+	return cpufreq_thermal_max_step;
 }
 
 static int cpufreq_get_cur_state(unsigned int cpu)
@@ -113,7 +122,8 @@ static int cpufreq_set_cur_state(unsigned int cpu, int state)
 		if (!policy)
 			return -EINVAL;
 
-		max_freq = (policy->cpuinfo.max_freq * (100 - reduction_pctg(i) * 20)) / 100;
+		max_freq = (policy->cpuinfo.max_freq *
+			    (100 - reduction_pctg(i) * cpufreq_thermal_pctg)) / 100;
 
 		cpufreq_cpu_put(policy);
 
@@ -126,10 +136,29 @@ static int cpufreq_set_cur_state(unsigned int cpu, int state)
 	return 0;
 }
 
+static void acpi_thermal_cpufreq_config(void)
+{
+	int cpufreq_pctg = acpi_thermal_cpufreq_pctg();
+
+	if (!cpufreq_pctg)
+		return;
+
+	cpufreq_thermal_pctg = cpufreq_pctg;
+
+	/*
+	 * Derive the MAX_STEP from minimum throttle percentage so that the reduction
+	 * percentage doesn't end up becoming negative. Also, cap the MAX_STEP so that
+	 * the CPU performance doesn't become 0.
+	 */
+	cpufreq_thermal_max_step = (100 / cpufreq_thermal_pctg) - 1;
+}
+
 void acpi_thermal_cpufreq_init(struct cpufreq_policy *policy)
 {
 	unsigned int cpu;
 
+	acpi_thermal_cpufreq_config();
+
 	for_each_cpu(cpu, policy->related_cpus) {
 		struct acpi_processor *pr = per_cpu(processors, cpu);
 		int ret;
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index ba3f601b6e3d..052c90d7479a 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1541,4 +1541,13 @@ static inline void acpi_device_notify(struct device *dev) { }
 static inline void acpi_device_notify_remove(struct device *dev) { }
 #endif
 
+#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
+int acpi_thermal_cpufreq_pctg(void);
+#else
+inline int acpi_thermal_cpufreq_pctg(void)
+{
+	return 0;
+}
+#endif
+
 #endif	/*_LINUX_ACPI_H*/
-- 
2.17.1

Re: [Patch v4 2/2] ACPI: processor: reduce CPUFREQ thermal reduction pctg for Tegra241

[kernel test robot]

Hi Sumit,

kernel test robot noticed the following build errors:

[auto build test ERROR on rafael-pm/linux-next]
[also build test ERROR on next-20231009]
[cannot apply to linus/master v6.6-rc5]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Sumit-Gupta/ACPI-thermal-Add-Thermal-fast-Sampling-Period-_TFP-support/20231010-012229
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
patch link:    https://lore.kernel.org/r/20231009171839.12267-3-sumitg%40nvidia.com
patch subject: [Patch v4 2/2] ACPI: processor: reduce CPUFREQ thermal reduction pctg for Tegra241
config: i386-tinyconfig (https://download.01.org/0day-ci/archive/20231010/202310100219.lpVzbckv-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231010/202310100219.lpVzbckv-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202310100219.lpVzbckv-lkp@intel.com/

All errors (new ones prefixed by >>):

   ld: arch/x86/kernel/setup.o: in function `acpi_thermal_cpufreq_pctg':
>> setup.c:(.text+0x3): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: arch/x86/kernel/x86_init.o: in function `acpi_thermal_cpufreq_pctg':
   x86_init.c:(.text+0x44): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: arch/x86/kernel/i8259.o: in function `acpi_thermal_cpufreq_pctg':
   i8259.c:(.text+0x2dd): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: arch/x86/kernel/irqinit.o: in function `acpi_thermal_cpufreq_pctg':
   irqinit.c:(.text+0x0): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: arch/x86/kernel/bootflag.o: in function `acpi_thermal_cpufreq_pctg':
   bootflag.c:(.text+0x0): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: arch/x86/kernel/e820.o: in function `acpi_thermal_cpufreq_pctg':
   e820.c:(.text+0x144): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: arch/x86/kernel/pci-dma.o: in function `acpi_thermal_cpufreq_pctg':
   pci-dma.c:(.text+0x0): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: arch/x86/kernel/process.o: in function `acpi_thermal_cpufreq_pctg':
   process.c:(.text+0xe5): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: kernel/sysctl.o: in function `acpi_thermal_cpufreq_pctg':
   sysctl.c:(.text+0x48): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: kernel/dma/mapping.o: in function `acpi_thermal_cpufreq_pctg':
   mapping.c:(.text+0x5ba): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: drivers/base/core.o: in function `acpi_thermal_cpufreq_pctg':
   core.c:(.text+0x13e9): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: drivers/base/platform.o: in function `acpi_thermal_cpufreq_pctg':
   platform.c:(.text+0x8b8): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: drivers/base/cpu.o: in function `acpi_thermal_cpufreq_pctg':
   cpu.c:(.text+0x128): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: drivers/base/property.o: in function `acpi_thermal_cpufreq_pctg':
   property.c:(.text+0xa87): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
   ld: drivers/base/cacheinfo.o: in function `acpi_thermal_cpufreq_pctg':
   cacheinfo.c:(.text+0x231): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [Patch v4 2/2] ACPI: processor: reduce CPUFREQ thermal reduction pctg for Tegra241

[Sumit Gupta]

> Hi Sumit,
> 
> kernel test robot noticed the following build errors:

Thank you for the report.

> 
> [auto build test ERROR on rafael-pm/linux-next]
> [also build test ERROR on next-20231009]
> [cannot apply to linus/master v6.6-rc5]

[...]

> All errors (new ones prefixed by >>):
> 
>     ld: arch/x86/kernel/setup.o: in function `acpi_thermal_cpufreq_pctg':
>>> setup.c:(.text+0x3): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
>     ld: arch/x86/kernel/x86_init.o: in function `acpi_thermal_cpufreq_pctg':

[...]

>     cpu.c:(.text+0x128): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
>     ld: drivers/base/property.o: in function `acpi_thermal_cpufreq_pctg':
>     property.c:(.text+0xa87): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here
>     ld: drivers/base/cacheinfo.o: in function `acpi_thermal_cpufreq_pctg':
>     cacheinfo.c:(.text+0x231): multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:main.c:(.text+0x32): first defined here

Below change fixes the issue for me.
  +++ b/include/linux/acpi.h
@@ -1542,7 +1542,7 @@ static inline void 
acpi_device_notify_remove(struct device *dev) { }
  #ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
  int acpi_thermal_cpufreq_pctg(void);
  #else
-inline int acpi_thermal_cpufreq_pctg(void)
+static inline int acpi_thermal_cpufreq_pctg(void)
  {
         return 0;
  }


Best Regards,
Sumit Gupta

Re: [Patch v4 2/2] ACPI: processor: reduce CPUFREQ thermal reduction pctg for Tegra241

[Sumit Gupta]

On 09/10/23 22:48, Sumit Gupta wrote:
> From: Srikar Srimath Tirumala <srikars@nvidia.com>
> 
> Current implementation of processor_thermal performs software throttling
> in fixed steps of "20%" which can be too coarse for some platforms.
> We observed some performance gain after reducing the throttle percentage.
> Change the CPUFREQ thermal reduction percentage and maximum thermal steps
> to be configurable. Also, update the default values of both for Nvidia
> Tegra241 (Grace) SoC. The thermal reduction percentage is reduced to "5%"
> and accordingly the maximum number of thermal steps are increased as they
> are derived from the reduction percentage.
> 
> Signed-off-by: Srikar Srimath Tirumala <srikars@nvidia.com>
> Co-developed-by: Sumit Gupta <sumitg@nvidia.com>
> Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
> ---
>   drivers/acpi/arm64/Makefile          |  1 +
>   drivers/acpi/arm64/thermal_cpufreq.c | 20 ++++++++++++++++
>   drivers/acpi/processor_thermal.c     | 35 +++++++++++++++++++++++++---
>   include/linux/acpi.h                 |  9 +++++++
>   4 files changed, 62 insertions(+), 3 deletions(-)
>   create mode 100644 drivers/acpi/arm64/thermal_cpufreq.c
> 
> diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
> index 143debc1ba4a..3f181d8156cc 100644
> --- a/drivers/acpi/arm64/Makefile
> +++ b/drivers/acpi/arm64/Makefile
> @@ -5,3 +5,4 @@ obj-$(CONFIG_ACPI_GTDT) 	+= gtdt.o
>   obj-$(CONFIG_ACPI_APMT) 	+= apmt.o
>   obj-$(CONFIG_ARM_AMBA)		+= amba.o
>   obj-y				+= dma.o init.o
> +obj-$(CONFIG_ACPI)		+= thermal_cpufreq.o
> diff --git a/drivers/acpi/arm64/thermal_cpufreq.c b/drivers/acpi/arm64/thermal_cpufreq.c
> new file mode 100644
> index 000000000000..de834fb013e7
> --- /dev/null
> +++ b/drivers/acpi/arm64/thermal_cpufreq.c
> @@ -0,0 +1,20 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include <linux/acpi.h>
> +
> +#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
> +#define SMCCC_SOC_ID_T241      0x036b0241
> +
> +int acpi_thermal_cpufreq_pctg(void)
> +{
> +	s32 soc_id = arm_smccc_get_soc_id_version();
> +
> +	/*
> +	 * Check JEP106 code for NVIDIA Tegra241 chip (036b:0241) and
> +	 * reduce the CPUFREQ Thermal reduction percentage to 5%.
> +	 */
> +	if (soc_id == SMCCC_SOC_ID_T241)
> +		return 5;
> +
> +	return 0;
> +}
> +#endif
> diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
> index b7c6287eccca..52f316e4e260 100644
> --- a/drivers/acpi/processor_thermal.c
> +++ b/drivers/acpi/processor_thermal.c
> @@ -26,7 +26,16 @@
>    */
>   
>   #define CPUFREQ_THERMAL_MIN_STEP 0
> -#define CPUFREQ_THERMAL_MAX_STEP 3
> +
> +static int cpufreq_thermal_max_step __read_mostly = 3;
> +
> +/*
> + * Minimum throttle percentage for processor_thermal cooling device.
> + * The processor_thermal driver uses it to calculate the percentage amount by
> + * which cpu frequency must be reduced for each cooling state. This is also used
> + * to calculate the maximum number of throttling steps or cooling states.
> + */
> +static int cpufreq_thermal_pctg __read_mostly = 20;
>   
>   static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
>   
> @@ -71,7 +80,7 @@ static int cpufreq_get_max_state(unsigned int cpu)
>   	if (!cpu_has_cpufreq(cpu))
>   		return 0;
>   
> -	return CPUFREQ_THERMAL_MAX_STEP;
> +	return cpufreq_thermal_max_step;
>   }
>   
>   static int cpufreq_get_cur_state(unsigned int cpu)
> @@ -113,7 +122,8 @@ static int cpufreq_set_cur_state(unsigned int cpu, int state)
>   		if (!policy)
>   			return -EINVAL;
>   
> -		max_freq = (policy->cpuinfo.max_freq * (100 - reduction_pctg(i) * 20)) / 100;
> +		max_freq = (policy->cpuinfo.max_freq *
> +			    (100 - reduction_pctg(i) * cpufreq_thermal_pctg)) / 100;
>   
>   		cpufreq_cpu_put(policy);
>   
> @@ -126,10 +136,29 @@ static int cpufreq_set_cur_state(unsigned int cpu, int state)
>   	return 0;
>   }
>   
> +static void acpi_thermal_cpufreq_config(void)
> +{
> +	int cpufreq_pctg = acpi_thermal_cpufreq_pctg();
> +
> +	if (!cpufreq_pctg)
> +		return;
> +
> +	cpufreq_thermal_pctg = cpufreq_pctg;
> +
> +	/*
> +	 * Derive the MAX_STEP from minimum throttle percentage so that the reduction
> +	 * percentage doesn't end up becoming negative. Also, cap the MAX_STEP so that
> +	 * the CPU performance doesn't become 0.
> +	 */
> +	cpufreq_thermal_max_step = (100 / cpufreq_thermal_pctg) - 1;
> +}
> +
>   void acpi_thermal_cpufreq_init(struct cpufreq_policy *policy)
>   {
>   	unsigned int cpu;
>   
> +	acpi_thermal_cpufreq_config();
> +
>   	for_each_cpu(cpu, policy->related_cpus) {
>   		struct acpi_processor *pr = per_cpu(processors, cpu);
>   		int ret;
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index ba3f601b6e3d..052c90d7479a 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -1541,4 +1541,13 @@ static inline void acpi_device_notify(struct device *dev) { }
>   static inline void acpi_device_notify_remove(struct device *dev) { }
>   #endif
>   
> +#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
> +int acpi_thermal_cpufreq_pctg(void);
> +#else
> +inline int acpi_thermal_cpufreq_pctg(void)
> +{
> +	return 0;
> +}
> +#endif
> +
>   #endif	/*_LINUX_ACPI_H*/

Hi Rafael,

The below change fixes the issue reported by the kernel test robot.
If there are no further comments, then I can send a v5 with this change?

+++ b/include/linux/acpi.h
@@ -1542,7 +1542,7 @@ static inline void 
acpi_device_notify_remove(struct device *dev) { }
  #ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
  int acpi_thermal_cpufreq_pctg(void);
  #else
-inline int acpi_thermal_cpufreq_pctg(void)
+static inline int acpi_thermal_cpufreq_pctg(void)
  {
         return 0;
  }

Best Regards,
Sumit Gupta

Re: [Patch v4 2/2] ACPI: processor: reduce CPUFREQ thermal reduction pctg for Tegra241

[kernel test robot]

Hi Sumit,

kernel test robot noticed the following build errors:

[auto build test ERROR on rafael-pm/linux-next]
[also build test ERROR on next-20231010]
[cannot apply to linus/master v6.6-rc5]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Sumit-Gupta/ACPI-thermal-Add-Thermal-fast-Sampling-Period-_TFP-support/20231010-012229
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
patch link:    https://lore.kernel.org/r/20231009171839.12267-3-sumitg%40nvidia.com
patch subject: [Patch v4 2/2] ACPI: processor: reduce CPUFREQ thermal reduction pctg for Tegra241
config: um-i386_defconfig (https://download.01.org/0day-ci/archive/20231010/202310101725.z21V2yNG-lkp@intel.com/config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231010/202310101725.z21V2yNG-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202310101725.z21V2yNG-lkp@intel.com/

All errors (new ones prefixed by >>):

   ld: kernel/sysctl.o: in function `acpi_thermal_cpufreq_pctg':
>> include/linux/acpi.h:1546: multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:include/linux/acpi.h:1546: first defined here
   ld: kernel/power/main.o: in function `acpi_thermal_cpufreq_pctg':
>> include/linux/acpi.h:1546: multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:include/linux/acpi.h:1546: first defined here
   ld: drivers/base/core.o: in function `acpi_thermal_cpufreq_pctg':
>> include/linux/acpi.h:1546: multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:include/linux/acpi.h:1546: first defined here
   ld: drivers/base/platform.o: in function `acpi_thermal_cpufreq_pctg':
>> include/linux/acpi.h:1546: multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:include/linux/acpi.h:1546: first defined here
   ld: drivers/base/cpu.o: in function `acpi_thermal_cpufreq_pctg':
>> include/linux/acpi.h:1546: multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:include/linux/acpi.h:1546: first defined here
   ld: drivers/base/property.o: in function `acpi_thermal_cpufreq_pctg':
>> include/linux/acpi.h:1546: multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:include/linux/acpi.h:1546: first defined here
   ld: drivers/base/cacheinfo.o: in function `acpi_thermal_cpufreq_pctg':
>> include/linux/acpi.h:1546: multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:include/linux/acpi.h:1546: first defined here
   ld: drivers/base/power/common.o: in function `acpi_thermal_cpufreq_pctg':
>> include/linux/acpi.h:1546: multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:include/linux/acpi.h:1546: first defined here
   ld: drivers/input/mouse/synaptics.o: in function `acpi_thermal_cpufreq_pctg':
>> include/linux/acpi.h:1546: multiple definition of `acpi_thermal_cpufreq_pctg'; init/main.o:include/linux/acpi.h:1546: first defined here


vim +1546 include/linux/acpi.h

  1541	
  1542	#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
  1543	int acpi_thermal_cpufreq_pctg(void);
  1544	#else
  1545	inline int acpi_thermal_cpufreq_pctg(void)
> 1546	{
  1547		return 0;
  1548	}
  1549	#endif
  1550	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki