diff mbox

[v2,4/6] cpufreq: intel_pstate: Use ACPI perf configuration

Message ID 1441108441-3388-5-git-send-email-srinivas.pandruvada@linux.intel.com (mailing list archive)
State Not Applicable, archived
Delegated to: Rafael Wysocki
Headers show

Commit Message

srinivas pandruvada Sept. 1, 2015, 11:53 a.m. UTC
Use ACPI _PSS to limit the Intel P State turbo, max and min ratios.
This driver uses acpi processor perf lib calls to register performance.
The following logic is used to adjust Intel P state driver limits:
- If there is no turbo entry in _PSS, then disable Intel P state turbo
and limit to non turbo max
- If the non turbo max ratio is more than _PSS max non turbo value, then
set the max non turbo ratio to _PSS non turbo max
- If the min ratio is less than _PSS min then change the min ratio
matching _PSS min
- Scale the _PSS turbo frequency to max turbo frequency based on control
value.
This feature can be disabled by using kernel parameters:
intel_pstate=no_acpi

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 drivers/cpufreq/Kconfig.x86    |   1 +
 drivers/cpufreq/intel_pstate.c | 142 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 142 insertions(+), 1 deletion(-)

Comments

Rafael J. Wysocki Sept. 26, 2015, 12:47 a.m. UTC | #1
On Tuesday, September 01, 2015 04:53:59 AM Srinivas Pandruvada wrote:
> Use ACPI _PSS to limit the Intel P State turbo, max and min ratios.
> This driver uses acpi processor perf lib calls to register performance.
> The following logic is used to adjust Intel P state driver limits:
> - If there is no turbo entry in _PSS, then disable Intel P state turbo
> and limit to non turbo max
> - If the non turbo max ratio is more than _PSS max non turbo value, then
> set the max non turbo ratio to _PSS non turbo max
> - If the min ratio is less than _PSS min then change the min ratio
> matching _PSS min
> - Scale the _PSS turbo frequency to max turbo frequency based on control
> value.
> This feature can be disabled by using kernel parameters:
> intel_pstate=no_acpi
> 
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> ---
>  drivers/cpufreq/Kconfig.x86    |   1 +
>  drivers/cpufreq/intel_pstate.c | 142 ++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 142 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86
> index c59bdcb..adbd1de 100644
> --- a/drivers/cpufreq/Kconfig.x86
> +++ b/drivers/cpufreq/Kconfig.x86
> @@ -5,6 +5,7 @@
>  config X86_INTEL_PSTATE
>         bool "Intel P state control"
>         depends on X86
> +       select ACPI_PROCESSOR if ACPI
>         help
>            This driver provides a P state for Intel core processors.
>  	  The driver implements an internal governor and will become
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index e92a59f..f5aa1da 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -34,6 +34,10 @@
>  #include <asm/cpu_device_id.h>
>  #include <asm/cpufeature.h>
>  
> +#if IS_ENABLED(CONFIG_ACPI)
> +#include <acpi/processor.h>
> +#endif
> +
>  #define BYT_RATIOS		0x66a
>  #define BYT_VIDS		0x66b
>  #define BYT_TURBO_RATIOS	0x66c
> @@ -114,6 +118,9 @@ struct cpudata {
>  	u64	prev_mperf;
>  	u64	prev_tsc;
>  	struct sample sample;
> +#if IS_ENABLED(CONFIG_ACPI)
> +	struct acpi_processor_performance acpi_perf_data;
> +#endif
>  };
>  
>  static struct cpudata **all_cpu_data;
> @@ -146,6 +153,7 @@ struct cpu_defaults {
>  static struct pstate_adjust_policy pid_params;
>  static struct pstate_funcs pstate_funcs;
>  static int hwp_active;
> +static int no_acpi_perf;
>  
>  struct perf_limits {
>  	int no_turbo;
> @@ -173,6 +181,124 @@ static struct perf_limits limits = {
>  	.min_sysfs_pct = 0,
>  };
>  
> +#if IS_ENABLED(CONFIG_ACPI)
> +static int intel_pstate_init_perf_limits(struct cpufreq_policy *policy)
> +{
> +	struct cpudata *cpu;
> +	int ret;
> +	int min_perf;
> +	bool turbo_absent = false;
> +	int max_pstate_index;
> +	int i;
> +
> +	cpu = all_cpu_data[policy->cpu];
> +
> +	if (!cpu->acpi_perf_data.shared_cpu_map &&
> +	    zalloc_cpumask_var_node(&cpu->acpi_perf_data.shared_cpu_map,
> +				    GFP_KERNEL, cpu_to_node(policy->cpu))) {
> +		return -ENOMEM;
> +	}
> +
> +	ret = acpi_processor_register_performance(&cpu->acpi_perf_data,
> +						  policy->cpu);
> +	if (ret)
> +		return ret;
> +
> +	/* Check if the control value in _PSS is for PERF_CTL MSR */

I'd add

	"which should guarantee that the states returned by it map to the states
	 in our list directly."

> +	if (cpu->acpi_perf_data.control_register.space_id !=
> +						ACPI_ADR_SPACE_FIXED_HARDWARE)
> +		return -EIO;
> +
> +	pr_debug("intel_pstate: CPU%u - ACPI _PSS perf data\n", policy->cpu);
> +	for (i = 0; i < cpu->acpi_perf_data.state_count; i++)
> +		pr_debug("     %cP%d: %u MHz, %u mW, 0x%x\n",
> +			 (i == cpu->acpi_perf_data.state ? '*' : ' '), i,
> +			 (u32) cpu->acpi_perf_data.states[i].core_frequency,
> +			 (u32) cpu->acpi_perf_data.states[i].power,
> +			 (u32) cpu->acpi_perf_data.states[i].control);
> +
> +	/*
> +	 * If there is only one entry _PSS, simply ignore _PSS and continue as
> +	 * usual without taking _PSS into account
> +	 */
> +	if (cpu->acpi_perf_data.state_count < 2)
> +		return 0;
> +
> +	/* Check if there is a turbo freq in _PSS */
> +	if ((cpu->acpi_perf_data.states[0].control >> 8) <=

I'd like the formula

	cpu->acpi_perf_data.states[i].control >> 8

to go into a separate function taking cpu and i as args and having a comment
explaining where this formula comes from next to it. 

> +	    cpu->pstate.max_pstate) {
> +		pr_debug("intel_pstate: no turbo range exists in _PSS\n");
> +		limits.no_turbo = limits.turbo_disabled = 1;
> +		cpu->pstate.turbo_pstate = cpu->pstate.max_pstate;
> +		turbo_absent = true;
> +	}
> +
> +	/* Check if the max non turbo p state < Intel P state max */
> +	if (turbo_absent)
> +		max_pstate_index = 0;
> +	else
> +		max_pstate_index = 1;

What about

	max_pstate_index = turbo_absent ? 0 : 1;

> +	if ((cpu->acpi_perf_data.states[max_pstate_index].control >> 8) <
> +	    cpu->pstate.max_pstate)
> +		cpu->pstate.max_pstate =
> +			cpu->acpi_perf_data.states[max_pstate_index].control;

Something is suspicious here.  Did you forget about the >> 8?

If so, I'd probably use an auxiliary variable for that, ie

	acpi_perf_max_pstate = cpu->acpi_perf_data.states[max_pstate_index].control >> 8;
	if (acpi_perf_max_pstate < cpu->pstate.max_pstate)
		cpu->pstate.max_pstate = acpi_perf_max_pstate;

> +
> +	/* check If min perf > Intel P State min */
> +	min_perf = cpu->acpi_perf_data.states[
> +			cpu->acpi_perf_data.state_count - 1].control >> 8;
> +	if (min_perf > cpu->pstate.min_pstate &&
> +	    min_perf < cpu->pstate.max_pstate) {
> +		cpu->pstate.min_pstate = min_perf;
> +		policy->cpuinfo.min_freq = cpu->pstate.min_pstate *
> +						cpu->pstate.scaling;
> +	}
> +
> +	if (turbo_absent)
> +		policy->cpuinfo.max_freq =
> +			cpu->pstate.max_pstate * cpu->pstate.scaling;
> +	else {
> +		policy->cpuinfo.max_freq =
> +			cpu->pstate.turbo_pstate * cpu->pstate.scaling;
> +		/* scale freq to intel pstate turbo scale */
> +		cpu->acpi_perf_data.states[0].core_frequency =
> +				cpu->pstate.scaling *
> +				(cpu->acpi_perf_data.states[0].control >> 8);
> +	}
> +
> +	pr_debug("intel_pstate: Updated limits 0x%x 0x%x 0x%x\n",
> +		 cpu->pstate.min_pstate, cpu->pstate.max_pstate,
> +		 cpu->pstate.turbo_pstate);
> +	pr_debug("intel_pstate: policy max_freq=%d Khz min_freq = %d KHz\n",
> +		 policy->cpuinfo.max_freq, policy->cpuinfo.min_freq);
> +
> +	return 0;
> +}
> +
> +static int intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
> +{
> +	struct cpudata *cpu;
> +
> +	if (!no_acpi_perf)
> +		return 0;
> +
> +	cpu = all_cpu_data[policy->cpu];
> +	acpi_processor_unregister_performance(&cpu->acpi_perf_data,
> +					      policy->cpu);
> +	return 0;
> +}
> +
> +#else
> +static int intel_pstate_init_perf_limits(struct cpufreq_policy *policy)
> +{
> +	return 0;
> +}
> +
> +static int intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
> +{
> +	return 0;
> +}
> +#endif
> +
>  static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
>  			     int deadband, int integral) {
>  	pid->setpoint = setpoint;
> @@ -1182,18 +1308,30 @@ static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
>  	policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling;
>  	policy->cpuinfo.max_freq =
>  		cpu->pstate.turbo_pstate * cpu->pstate.scaling;
> +	if (!no_acpi_perf)
> +		intel_pstate_init_perf_limits(policy);
> +	/*
> +	 * If there is no acpi perf data or error, we ignore and use Intel P
> +	 * state calculated limits, So this is not fatal error.
> +	 */
>  	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
>  	cpumask_set_cpu(policy->cpu, policy->cpus);
>  
>  	return 0;
>  }
>  
> +static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
> +{
> +	return intel_pstate_exit_perf_limits(policy);
> +}
> +
>  static struct cpufreq_driver intel_pstate_driver = {
>  	.flags		= CPUFREQ_CONST_LOOPS,
>  	.verify		= intel_pstate_verify_policy,
>  	.setpolicy	= intel_pstate_set_policy,
>  	.get		= intel_pstate_get,
>  	.init		= intel_pstate_cpu_init,
> +	.exit		= intel_pstate_cpu_exit,
>  	.stop_cpu	= intel_pstate_stop_cpu,
>  	.name		= "intel_pstate",
>  };
> @@ -1237,7 +1375,6 @@ static void copy_cpu_funcs(struct pstate_funcs *funcs)
>  }
>  
>  #if IS_ENABLED(CONFIG_ACPI)
> -#include <acpi/processor.h>
>  
>  static bool intel_pstate_no_acpi_pss(void)
>  {
> @@ -1425,6 +1562,9 @@ static int __init intel_pstate_setup(char *str)
>  		force_load = 1;
>  	if (!strcmp(str, "hwp_only"))
>  		hwp_only = 1;
> +	if (!strcmp(str, "no_acpi"))
> +		no_acpi_perf = 1;
> +
>  	return 0;
>  }
>  early_param("intel_pstate", intel_pstate_setup);

The other patches in this series need ACKs from Kristen.

Thanks,
Rafael

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diff mbox

Patch

diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86
index c59bdcb..adbd1de 100644
--- a/drivers/cpufreq/Kconfig.x86
+++ b/drivers/cpufreq/Kconfig.x86
@@ -5,6 +5,7 @@ 
 config X86_INTEL_PSTATE
        bool "Intel P state control"
        depends on X86
+       select ACPI_PROCESSOR if ACPI
        help
           This driver provides a P state for Intel core processors.
 	  The driver implements an internal governor and will become
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index e92a59f..f5aa1da 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -34,6 +34,10 @@ 
 #include <asm/cpu_device_id.h>
 #include <asm/cpufeature.h>
 
+#if IS_ENABLED(CONFIG_ACPI)
+#include <acpi/processor.h>
+#endif
+
 #define BYT_RATIOS		0x66a
 #define BYT_VIDS		0x66b
 #define BYT_TURBO_RATIOS	0x66c
@@ -114,6 +118,9 @@  struct cpudata {
 	u64	prev_mperf;
 	u64	prev_tsc;
 	struct sample sample;
+#if IS_ENABLED(CONFIG_ACPI)
+	struct acpi_processor_performance acpi_perf_data;
+#endif
 };
 
 static struct cpudata **all_cpu_data;
@@ -146,6 +153,7 @@  struct cpu_defaults {
 static struct pstate_adjust_policy pid_params;
 static struct pstate_funcs pstate_funcs;
 static int hwp_active;
+static int no_acpi_perf;
 
 struct perf_limits {
 	int no_turbo;
@@ -173,6 +181,124 @@  static struct perf_limits limits = {
 	.min_sysfs_pct = 0,
 };
 
+#if IS_ENABLED(CONFIG_ACPI)
+static int intel_pstate_init_perf_limits(struct cpufreq_policy *policy)
+{
+	struct cpudata *cpu;
+	int ret;
+	int min_perf;
+	bool turbo_absent = false;
+	int max_pstate_index;
+	int i;
+
+	cpu = all_cpu_data[policy->cpu];
+
+	if (!cpu->acpi_perf_data.shared_cpu_map &&
+	    zalloc_cpumask_var_node(&cpu->acpi_perf_data.shared_cpu_map,
+				    GFP_KERNEL, cpu_to_node(policy->cpu))) {
+		return -ENOMEM;
+	}
+
+	ret = acpi_processor_register_performance(&cpu->acpi_perf_data,
+						  policy->cpu);
+	if (ret)
+		return ret;
+
+	/* Check if the control value in _PSS is for PERF_CTL MSR */
+	if (cpu->acpi_perf_data.control_register.space_id !=
+						ACPI_ADR_SPACE_FIXED_HARDWARE)
+		return -EIO;
+
+	pr_debug("intel_pstate: CPU%u - ACPI _PSS perf data\n", policy->cpu);
+	for (i = 0; i < cpu->acpi_perf_data.state_count; i++)
+		pr_debug("     %cP%d: %u MHz, %u mW, 0x%x\n",
+			 (i == cpu->acpi_perf_data.state ? '*' : ' '), i,
+			 (u32) cpu->acpi_perf_data.states[i].core_frequency,
+			 (u32) cpu->acpi_perf_data.states[i].power,
+			 (u32) cpu->acpi_perf_data.states[i].control);
+
+	/*
+	 * If there is only one entry _PSS, simply ignore _PSS and continue as
+	 * usual without taking _PSS into account
+	 */
+	if (cpu->acpi_perf_data.state_count < 2)
+		return 0;
+
+	/* Check if there is a turbo freq in _PSS */
+	if ((cpu->acpi_perf_data.states[0].control >> 8) <=
+	    cpu->pstate.max_pstate) {
+		pr_debug("intel_pstate: no turbo range exists in _PSS\n");
+		limits.no_turbo = limits.turbo_disabled = 1;
+		cpu->pstate.turbo_pstate = cpu->pstate.max_pstate;
+		turbo_absent = true;
+	}
+
+	/* Check if the max non turbo p state < Intel P state max */
+	if (turbo_absent)
+		max_pstate_index = 0;
+	else
+		max_pstate_index = 1;
+	if ((cpu->acpi_perf_data.states[max_pstate_index].control >> 8) <
+	    cpu->pstate.max_pstate)
+		cpu->pstate.max_pstate =
+			cpu->acpi_perf_data.states[max_pstate_index].control;
+
+	/* check If min perf > Intel P State min */
+	min_perf = cpu->acpi_perf_data.states[
+			cpu->acpi_perf_data.state_count - 1].control >> 8;
+	if (min_perf > cpu->pstate.min_pstate &&
+	    min_perf < cpu->pstate.max_pstate) {
+		cpu->pstate.min_pstate = min_perf;
+		policy->cpuinfo.min_freq = cpu->pstate.min_pstate *
+						cpu->pstate.scaling;
+	}
+
+	if (turbo_absent)
+		policy->cpuinfo.max_freq =
+			cpu->pstate.max_pstate * cpu->pstate.scaling;
+	else {
+		policy->cpuinfo.max_freq =
+			cpu->pstate.turbo_pstate * cpu->pstate.scaling;
+		/* scale freq to intel pstate turbo scale */
+		cpu->acpi_perf_data.states[0].core_frequency =
+				cpu->pstate.scaling *
+				(cpu->acpi_perf_data.states[0].control >> 8);
+	}
+
+	pr_debug("intel_pstate: Updated limits 0x%x 0x%x 0x%x\n",
+		 cpu->pstate.min_pstate, cpu->pstate.max_pstate,
+		 cpu->pstate.turbo_pstate);
+	pr_debug("intel_pstate: policy max_freq=%d Khz min_freq = %d KHz\n",
+		 policy->cpuinfo.max_freq, policy->cpuinfo.min_freq);
+
+	return 0;
+}
+
+static int intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
+{
+	struct cpudata *cpu;
+
+	if (!no_acpi_perf)
+		return 0;
+
+	cpu = all_cpu_data[policy->cpu];
+	acpi_processor_unregister_performance(&cpu->acpi_perf_data,
+					      policy->cpu);
+	return 0;
+}
+
+#else
+static int intel_pstate_init_perf_limits(struct cpufreq_policy *policy)
+{
+	return 0;
+}
+
+static int intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
+{
+	return 0;
+}
+#endif
+
 static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
 			     int deadband, int integral) {
 	pid->setpoint = setpoint;
@@ -1182,18 +1308,30 @@  static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
 	policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling;
 	policy->cpuinfo.max_freq =
 		cpu->pstate.turbo_pstate * cpu->pstate.scaling;
+	if (!no_acpi_perf)
+		intel_pstate_init_perf_limits(policy);
+	/*
+	 * If there is no acpi perf data or error, we ignore and use Intel P
+	 * state calculated limits, So this is not fatal error.
+	 */
 	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
 	cpumask_set_cpu(policy->cpu, policy->cpus);
 
 	return 0;
 }
 
+static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
+{
+	return intel_pstate_exit_perf_limits(policy);
+}
+
 static struct cpufreq_driver intel_pstate_driver = {
 	.flags		= CPUFREQ_CONST_LOOPS,
 	.verify		= intel_pstate_verify_policy,
 	.setpolicy	= intel_pstate_set_policy,
 	.get		= intel_pstate_get,
 	.init		= intel_pstate_cpu_init,
+	.exit		= intel_pstate_cpu_exit,
 	.stop_cpu	= intel_pstate_stop_cpu,
 	.name		= "intel_pstate",
 };
@@ -1237,7 +1375,6 @@  static void copy_cpu_funcs(struct pstate_funcs *funcs)
 }
 
 #if IS_ENABLED(CONFIG_ACPI)
-#include <acpi/processor.h>
 
 static bool intel_pstate_no_acpi_pss(void)
 {
@@ -1425,6 +1562,9 @@  static int __init intel_pstate_setup(char *str)
 		force_load = 1;
 	if (!strcmp(str, "hwp_only"))
 		hwp_only = 1;
+	if (!strcmp(str, "no_acpi"))
+		no_acpi_perf = 1;
+
 	return 0;
 }
 early_param("intel_pstate", intel_pstate_setup);