@@ -1661,6 +1661,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
hwp_only
Only load intel_pstate on systems which support
hardware P state control (HWP) if available.
+ support_acpi_ppc
+ Enforce ACPI _PPC performance limits.
intremap= [X86-64, Intel-IOMMU]
on enable Interrupt Remapping (default)
@@ -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
@@ -39,6 +39,10 @@
#define ATOM_TURBO_RATIOS 0x66c
#define ATOM_TURBO_VIDS 0x66d
+#ifdef CONFIG_ACPI
+#include <acpi/processor.h>
+#endif
+
#define FRAC_BITS 8
#define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
#define fp_toint(X) ((X) >> FRAC_BITS)
@@ -172,6 +176,8 @@ struct _pid {
* @prev_cummulative_iowait: IO Wait time difference from last and
* current sample
* @sample: Storage for storing last Sample data
+ * @acpi_perf_data: Stores ACPI perf information read from _PSS
+ * @valid_pss_table: Set to true for valid ACPI _PSS entries found
*
* This structure stores per CPU instance data for all CPUs.
*/
@@ -190,6 +196,10 @@ struct cpudata {
u64 prev_tsc;
u64 prev_cummulative_iowait;
struct sample sample;
+#ifdef CONFIG_ACPI
+ struct acpi_processor_performance acpi_perf_data;
+ bool valid_pss_table;
+#endif
};
static struct cpudata **all_cpu_data;
@@ -258,6 +268,9 @@ static struct pstate_adjust_policy pid_params;
static struct pstate_funcs pstate_funcs;
static int hwp_active;
+#ifdef CONFIG_ACPI
+static bool acpi_ppc;
+#endif
/**
* struct perf_limits - Store user and policy limits
@@ -331,6 +344,110 @@ static struct perf_limits *limits = &performance_limits;
static struct perf_limits *limits = &powersave_limits;
#endif
+#ifdef CONFIG_ACPI
+/*
+ * The max target pstate ratio is a 8 bit value in both PLATFORM_INFO MSR and
+ * in TURBO_RATIO_LIMIT MSR, which pstate driver stores in max_pstate and
+ * max_turbo_pstate fields. The PERF_CTL MSR contains 16 bit value for P state
+ * ratio, out of it only high 8 bits are used. For example 0x1700 is setting
+ * target ratio 0x17. The _PSS control value stores in a format which can be
+ * directly written to PERF_CTL MSR. But in intel_pstate driver this shift
+ * occurs during write to PERF_CTL (E.g. for cores core_set_pstate()).
+ * This function converts the _PSS control value to intel pstate driver format
+ * for comparison and assignment.
+ */
+static int convert_to_native_pstate_format(struct cpudata *cpu, int index)
+{
+ return cpu->acpi_perf_data.states[index].control >> 8;
+}
+
+static void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy)
+{
+ struct cpudata *cpu;
+ int turbo_pss_ctl;
+ int ret;
+ int i;
+
+ if (!acpi_ppc)
+ return;
+
+ cpu = all_cpu_data[policy->cpu];
+
+ ret = acpi_processor_register_performance(&cpu->acpi_perf_data,
+ policy->cpu);
+ if (ret)
+ return;
+
+ /*
+ * Check if the control value in _PSS is for PERF_CTL MSR, 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)
+ goto err_unreg_perf;
+
+ /*
+ * 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)
+ goto err_unreg_perf;
+
+ pr_debug("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);
+ }
+
+ /*
+ * The _PSS table doesn't contain whole turbo frequency range.
+ * This just contains +1 MHZ above the max non turbo frequency,
+ * with control value corresponding to max turbo ratio. But
+ * when cpufreq set policy is called, it will call with this
+ * max frequency, which will cause a reduced performance as
+ * this driver uses real max turbo frequency as the max
+ * frequency. So correct this frequency in _PSS table to
+ * correct max turbo frequency based on the turbo ratio.
+ * Also need to convert to MHz as _PSS freq is in MHz.
+ */
+ turbo_pss_ctl = convert_to_native_pstate_format(cpu, 0);
+ if (turbo_pss_ctl > cpu->pstate.max_pstate)
+ cpu->acpi_perf_data.states[0].core_frequency =
+ policy->cpuinfo.max_freq / 1000;
+ cpu->valid_pss_table = true;
+ pr_info("_PPC limits will be enforced\n");
+
+ return;
+err_unreg_perf:
+ cpu->valid_pss_table = false;
+ acpi_processor_unregister_performance(policy->cpu);
+}
+
+static void intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
+{
+ struct cpudata *cpu;
+
+ cpu = all_cpu_data[policy->cpu];
+ if (!cpu->valid_pss_table)
+ return;
+
+ acpi_processor_unregister_performance(policy->cpu);
+}
+
+#else
+static void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy)
+{
+}
+
+static void intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
+{
+}
+#endif
+
static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
int deadband, int integral) {
pid->setpoint = int_tofp(setpoint);
@@ -1396,18 +1513,27 @@ 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;
+ intel_pstate_init_acpi_perf_limits(policy);
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)
+{
+ intel_pstate_exit_perf_limits(policy);
+
+ return 0;
+}
+
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",
};
@@ -1451,8 +1577,7 @@ static void copy_cpu_funcs(struct pstate_funcs *funcs)
}
-#if IS_ENABLED(CONFIG_ACPI)
-#include <acpi/processor.h>
+#ifdef CONFIG_ACPI
static bool intel_pstate_no_acpi_pss(void)
{
@@ -1658,6 +1783,12 @@ static int __init intel_pstate_setup(char *str)
force_load = 1;
if (!strcmp(str, "hwp_only"))
hwp_only = 1;
+
+#ifdef CONFIG_ACPI
+ if (!strcmp(str, "support_acpi_ppc"))
+ acpi_ppc = true;
+#endif
+
return 0;
}
early_param("intel_pstate", intel_pstate_setup);
Use ACPI _PPC notification to limit max P state driver will request. ACPI _PPC change notification is sent by BIOS to limit max P state in several cases: - Reduce impact of platform thermal condition - When Config TDP feature is used, a changed _PPC is sent to follow TDP change - Remote node managers in server want to control platform power via baseboard management controller (BMC) This change registers with ACPI processor performance lib so that _PPC changes are notified to cpufreq core, which in turns will result in call to .setpolicy() callback. Also the way _PSS table identifies a turbo frequency is not compatible to max turbo frequency in intel_pstate, so the very first entry in _PSS needs to be adjusted. This feature can be turned on by using kernel parameters: intel_pstate=support_acpi_ppc Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> --- Documentation/kernel-parameters.txt | 2 + drivers/cpufreq/Kconfig.x86 | 1 + drivers/cpufreq/intel_pstate.c | 135 +++++++++++++++++++++++++++++++++++- 3 files changed, 136 insertions(+), 2 deletions(-)