Revert "cpufreq: intel_pstate: Use ACPI perf configuration"
Revert commit 37afb0003242 (cpufreq: intel_pstate: Use ACPI perf
configuration) that is reported to cause a regression to happen
on a system where invalid data are returned by the ACPI _PSS object.
Since that commit makes assumptions regarding the _PSS output
correctness that may turn out to be overly optimistic in general,
there is a concern that it may introduce regression on more
systems, so it's better to revert it now and we'll revisit the
underlying issue in the next cycle with a more robust solution.
Conflicts:
drivers/cpufreq/intel_pstate.c
Fixes: 37afb0003242 (cpufreq: intel_pstate: Use ACPI perf configuration)
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index d444000..ef05944 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -34,10 +34,6 @@
#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
@@ -117,9 +113,6 @@
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;
@@ -150,7 +143,6 @@
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;
@@ -197,153 +189,6 @@
static struct perf_limits *limits = &powersave_limits;
#endif
-#if IS_ENABLED(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 int intel_pstate_init_perf_limits(struct cpufreq_policy *policy)
-{
- struct cpudata *cpu;
- int ret;
- bool turbo_absent = false;
- int max_pstate_index;
- int min_pss_ctl, max_pss_ctl, turbo_pss_ctl;
- int i;
-
- cpu = all_cpu_data[policy->cpu];
-
- pr_debug("intel_pstate: default limits 0x%x 0x%x 0x%x\n",
- cpu->pstate.min_pstate, cpu->pstate.max_pstate,
- cpu->pstate.turbo_pstate);
-
- 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, 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;
-
- turbo_pss_ctl = convert_to_native_pstate_format(cpu, 0);
- min_pss_ctl = convert_to_native_pstate_format(cpu,
- cpu->acpi_perf_data.state_count - 1);
- /* Check if there is a turbo freq in _PSS */
- if (turbo_pss_ctl <= cpu->pstate.max_pstate &&
- turbo_pss_ctl > cpu->pstate.min_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 */
- max_pstate_index = turbo_absent ? 0 : 1;
- max_pss_ctl = convert_to_native_pstate_format(cpu, max_pstate_index);
- if (max_pss_ctl < cpu->pstate.max_pstate &&
- max_pss_ctl > cpu->pstate.min_pstate)
- cpu->pstate.max_pstate = max_pss_ctl;
-
- /* check If min perf > Intel P State min */
- if (min_pss_ctl > cpu->pstate.min_pstate &&
- min_pss_ctl < cpu->pstate.max_pstate) {
- cpu->pstate.min_pstate = min_pss_ctl;
- policy->cpuinfo.min_freq = min_pss_ctl * 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;
- /*
- * 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
- * frequeny. 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.
- */
- cpu->acpi_perf_data.states[0].core_frequency =
- turbo_pss_ctl * 100;
- }
-
- pr_debug("intel_pstate: Updated limits using _PSS 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(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;
@@ -1303,30 +1148,18 @@
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",
};
@@ -1368,6 +1201,7 @@
}
#if IS_ENABLED(CONFIG_ACPI)
+#include <acpi/processor.h>
static bool intel_pstate_no_acpi_pss(void)
{
@@ -1563,9 +1397,6 @@
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);