The intel_pstate driver is ported following its kernel code logic
(commit: 93f0822d).
In the kernel, a user can adjust the limits via sysfs
(limits.min_sysfs_pct/max_sysfs_pct). In Xen, the
policy->min_perf_pct/max_perf_pct acts as the transit station.
A user interacts with it via xenpm.
Signed-off-by: Wei Wang <wei.w.w...@intel.com>
---
xen/arch/x86/acpi/cpufreq/Makefile | 1 +
xen/arch/x86/acpi/cpufreq/intel_pstate.c | 852 +++++++++++++++++++++++++++++++
xen/include/acpi/cpufreq/cpufreq.h | 6 +
xen/include/asm-x86/acpi.h | 2 +
xen/include/asm-x86/cpufeature.h | 1 +
xen/include/asm-x86/msr-index.h | 3 +
6 files changed, 865 insertions(+)
create mode 100644 xen/arch/x86/acpi/cpufreq/intel_pstate.c
diff --git a/xen/arch/x86/acpi/cpufreq/Makefile
b/xen/arch/x86/acpi/cpufreq/Makefile
index f75da9b..99fa9f4 100644
--- a/xen/arch/x86/acpi/cpufreq/Makefile
+++ b/xen/arch/x86/acpi/cpufreq/Makefile
@@ -1,2 +1,3 @@
obj-y += cpufreq.o
+obj-y += intel_pstate.o
obj-y += powernow.o
diff --git a/xen/arch/x86/acpi/cpufreq/intel_pstate.c
b/xen/arch/x86/acpi/cpufreq/intel_pstate.c
new file mode 100644
index 0000000..052a0d0
--- /dev/null
+++ b/xen/arch/x86/acpi/cpufreq/intel_pstate.c
@@ -0,0 +1,852 @@
+#include <xen/kernel.h>
+#include <xen/types.h>
+#include <xen/init.h>
+#include <xen/bitmap.h>
+#include <xen/cpumask.h>
+#include <xen/timer.h>
+#include <asm/msr.h>
+#include <asm/msr-index.h>
+#include <asm/processor.h>
+#include <asm/div64.h>
+#include <acpi/cpufreq/cpufreq.h>
+
+#define BYT_RATIOS 0x66a
+#define BYT_VIDS 0x66b
+#define BYT_TURBO_RATIOS 0x66c
+#define BYT_TURBO_VIDS 0x66d
+
+#define FRAC_BITS 8
+#define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
+#define fp_toint(X) ((X) >> FRAC_BITS)
+
+static inline int32_t mul_fp(int32_t x, int32_t y)
+{
+ return ((int64_t)x * (int64_t)y) >> FRAC_BITS;
+}
+
+static inline int32_t div_fp(int32_t x, int32_t y)
+{
+ return div_s64((int64_t)x << FRAC_BITS, y);
+}
+
+static inline int ceiling_fp(int32_t x)
+{
+ int mask, ret;
+
+ ret = fp_toint(x);
+ mask = (1 << FRAC_BITS) - 1;
+ if (x & mask)
+ ret += 1;
+ return ret;
+}
+
+struct sample {
+ int32_t core_pct_busy;
+ u64 aperf;
+ u64 mperf;
+ int freq;
+ s_time_t time;
+};
+
+struct pstate_data {
+ int current_pstate;
+ int min_pstate;
+ int max_pstate;
+ int scaling;
+ int turbo_pstate;
+};
+
+struct vid_data {
+ int min;
+ int max;
+ int turbo;
+ int32_t ratio;
+};
+
+struct _pid {
+ int setpoint;
+ int32_t integral;
+ int32_t p_gain;
+ int32_t i_gain;
+ int32_t d_gain;
+ int deadband;
+ int32_t last_err;
+};
+
+struct cpudata {
+ int cpu;
+
+ struct timer timer;
+
+ struct pstate_data pstate;
+ struct vid_data vid;
+ struct _pid pid;
+
+ s_time_t last_sample_time;
+ u64 prev_aperf;
+ u64 prev_mperf;
+ struct sample sample;
+};
+
+static struct cpudata **all_cpu_data;
+
+struct pstate_adjust_policy {
+ int sample_rate_ms;
+ int deadband;
+ int setpoint;
+ int p_gain_pct;
+ int d_gain_pct;
+ int i_gain_pct;
+};
+
+struct pstate_funcs {
+ int (*get_max)(void);
+ int (*get_min)(void);
+ int (*get_turbo)(void);
+ int (*get_scaling)(void);
+ void (*set)(struct cpudata*, int pstate);
+ void (*get_vid)(struct cpudata *);
+};
+
+struct cpu_defaults {
+ struct pstate_adjust_policy pid_policy;
+ struct pstate_funcs funcs;
+};
+
+static struct pstate_adjust_policy pid_params;
+static struct pstate_funcs pstate_funcs;
+
+struct perf_limits {
+ int no_turbo;
+ int turbo_disabled;
+ int max_perf_pct;
+ int min_perf_pct;
+ int32_t max_perf;
+ int32_t min_perf;
+ int max_policy_pct;
+ int min_policy_pct;
+};
+
+static struct perf_limits limits = {
+ .no_turbo = 0,
+ .turbo_disabled = 0,
+ .max_perf_pct = 100,
+ .max_perf = int_tofp(1),
+ .min_perf_pct = 0,
+ .min_perf = 0,
+ .max_policy_pct = 100,
+ .min_policy_pct = 0,
+};
+
+static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
+ int deadband, int integral)
+{
+ pid->setpoint = setpoint;
+ pid->deadband = deadband;
+ pid->integral = int_tofp(integral);
+ pid->last_err = int_tofp(setpoint) - int_tofp(busy);
+}
+
+static inline void pid_p_gain_set(struct _pid *pid, int percent)
+{
+ pid->p_gain = div_fp(int_tofp(percent), int_tofp(100));
+}
+
+static inline void pid_i_gain_set(struct _pid *pid, int percent)
+{
+ pid->i_gain = div_fp(int_tofp(percent), int_tofp(100));
+}
+
+static inline void pid_d_gain_set(struct _pid *pid, int percent)
+{
+ pid->d_gain = div_fp(int_tofp(percent), int_tofp(100));
+}
+
+static signed int pid_calc(struct _pid *pid, int32_t busy)
+{
+ signed int result;
+ int32_t pterm, dterm, fp_error;
+ int32_t integral_limit;
+
+ fp_error = int_tofp(pid->setpoint) - busy;
+
+ if (abs(fp_error) <= int_tofp(pid->deadband))
+ return 0;
+
+ pterm = mul_fp(pid->p_gain, fp_error);
+
+ pid->integral += fp_error;
+
+ /*
+ * We limit the integral here so that it will never
+ * get higher than 30. This prevents it from becoming
+ * too large an input over long periods of time and allows
+ * it to get factored out sooner.
+ * The value of 30 was chosen through experimentation.
+ */
+ integral_limit = int_tofp(30);
+ if (pid->integral > integral_limit)
+ pid->integral = integral_limit;
+ if (pid->integral < -integral_limit)
+ pid->integral = -integral_limit;
+
+ dterm = mul_fp(pid->d_gain, fp_error - pid->last_err);
+ pid->last_err = fp_error;
+
+ result = pterm + mul_fp(pid->integral, pid->i_gain) + dterm;
+ result = result + (1 << (FRAC_BITS-1));
+ return (signed int)fp_toint(result);
+}
+
+static inline void intel_pstate_busy_pid_reset(struct cpudata *cpu)
+{
+ pid_p_gain_set(&cpu->pid, pid_params.p_gain_pct);
+ pid_d_gain_set(&cpu->pid, pid_params.d_gain_pct);
+ pid_i_gain_set(&cpu->pid, pid_params.i_gain_pct);
+
+ pid_reset(&cpu->pid, pid_params.setpoint, 100, pid_params.deadband, 0);
+}
+
+static inline void intel_pstate_reset_all_pid(void)
+{
+ unsigned int cpu;
+
+ for_each_online_cpu(cpu) {
+ if (all_cpu_data[cpu])
+ intel_pstate_busy_pid_reset(all_cpu_data[cpu]);
+ }
+}
+
+static inline void update_turbo_state(void)
+{
+ u64 misc_en;
+ struct cpudata *cpu;
+
+ cpu = all_cpu_data[0];
+ rdmsrl(MSR_IA32_MISC_ENABLE, misc_en);
+ limits.turbo_disabled =
+ (misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE ||
+ cpu->pstate.max_pstate == cpu->pstate.turbo_pstate);
+}
+
+static int byt_get_min_pstate(void)
+{
+ u64 value;
+
+ rdmsrl(BYT_RATIOS, value);
+ return (value >> 8) & 0x7F;
+}
+
+static int byt_get_max_pstate(void)
+{
+ u64 value;
+
+ rdmsrl(BYT_RATIOS, value);
+ return (value >> 16) & 0x7F;
+}
+
+static int byt_get_turbo_pstate(void)
+{
+ u64 value;
+
+ rdmsrl(BYT_TURBO_RATIOS, value);
+ return value & 0x7F;
+}
+
+static void byt_set_pstate(struct cpudata *cpudata, int pstate)
+{
+ u64 val;
+ int32_t vid_fp;
+ u32 vid;
+
+ val = pstate << 8;
+ if (limits.no_turbo && !limits.turbo_disabled)
+ val |= (u64)1 << 32;
+
+ vid_fp = cpudata->vid.min + mul_fp(
+ int_tofp(pstate - cpudata->pstate.min_pstate),
+ cpudata->vid.ratio);
+
+ vid_fp = clamp_t(int32_t, vid_fp, cpudata->vid.min, cpudata->vid.max);
+ vid = ceiling_fp(vid_fp);
+
+ if (pstate > cpudata->pstate.max_pstate)
+ vid = cpudata->vid.turbo;
+
+ val |= vid;
+
+ wrmsrl(MSR_IA32_PERF_CTL, val);
+}
+
+#define BYT_BCLK_FREQS 5
+static int byt_freq_table[BYT_BCLK_FREQS] = { 833, 1000, 1333, 1167, 800};
+
+static int byt_get_scaling(void)
+{
+ u64 value;
+ int i;
+
+ rdmsrl(MSR_FSB_FREQ, value);
+ i = value & 0x3;
+
+ BUG_ON(i > BYT_BCLK_FREQS);
+
+ return byt_freq_table[i] * 100;
+}
+
+static void byt_get_vid(struct cpudata *cpudata)
+{
+ u64 value;
+
+ rdmsrl(BYT_VIDS, value);
+ cpudata->vid.min = int_tofp((value >> 8) & 0x7f);
+ cpudata->vid.max = int_tofp((value >> 16) & 0x7f);
+ cpudata->vid.ratio = div_fp(
+ cpudata->vid.max - cpudata->vid.min,
+ int_tofp(cpudata->pstate.max_pstate -
+ cpudata->pstate.min_pstate));
+
+ rdmsrl(BYT_TURBO_VIDS, value);
+ cpudata->vid.turbo = value & 0x7f;
+}
+
+static int core_get_min_pstate(void)
+{
+ u64 value;
+
+ rdmsrl(MSR_INTEL_PLATFORM_INFO, value);
+ return (value >> 40) & 0xFF;
+}
+
+static int core_get_max_pstate(void)
+{
+ u64 value;
+
+ rdmsrl(MSR_INTEL_PLATFORM_INFO, value);
+ return (value >> 8) & 0xFF;
+}
+
+static int core_get_turbo_pstate(void)
+{
+ u64 value;
+ int nont, ret;
+
+ rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
+ nont = core_get_max_pstate();
+ ret = (value) & 255;
+ if (ret <= nont)
+ ret = nont;
+ return ret;
+}
+
+static inline int core_get_scaling(void)
+{
+ return 100000;
+}
+
+static void core_set_pstate(struct cpudata *cpudata, int pstate)
+{
+ u64 val;
+
+ val = pstate << 8;
+ if (limits.no_turbo && !limits.turbo_disabled)
+ val |= (u64)1 << 32;
+
+ wrmsrl(MSR_IA32_PERF_CTL, val);
+}
+
+static struct cpu_defaults core_params = {
+ .pid_policy = {
+ .sample_rate_ms = 10,
+ .deadband = 0,
+ .setpoint = 97,
+ .p_gain_pct = 20,
+ .d_gain_pct = 0,
+ .i_gain_pct = 0,
+ },
+ .funcs = {
+ .get_max = core_get_max_pstate,
+ .get_min = core_get_min_pstate,
+ .get_turbo = core_get_turbo_pstate,
+ .get_scaling = core_get_scaling,
+ .set = core_set_pstate,
+ },
+};
+
+static struct cpu_defaults byt_params = {
+ .pid_policy = {
+ .sample_rate_ms = 10,
+ .deadband = 0,
+ .setpoint = 97,
+ .p_gain_pct = 14,
+ .d_gain_pct = 0,
+ .i_gain_pct = 4,
+ },
+ .funcs = {
+ .get_max = byt_get_max_pstate,
+ .get_min = byt_get_min_pstate,
+ .get_turbo = byt_get_turbo_pstate,
+ .set = byt_set_pstate,
+ .get_scaling = byt_get_scaling,
+ .get_vid = byt_get_vid,
+ },
+};
+
+static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
+{
+ int max_perf = cpu->pstate.turbo_pstate;
+ int max_perf_adj;
+ int min_perf;
+
+ if (limits.no_turbo || limits.turbo_disabled)
+ max_perf = cpu->pstate.max_pstate;
+
+ /* performance can be limited by user through xenpm */
+ max_perf_adj = fp_toint(mul_fp(int_tofp(max_perf), limits.max_perf));
+ *max = clamp_t(int, max_perf_adj,
+ cpu->pstate.min_pstate, cpu->pstate.turbo_pstate);
+
+ min_perf = fp_toint(mul_fp(int_tofp(max_perf), limits.min_perf));
+ *min = clamp_t(int, min_perf, cpu->pstate.min_pstate, max_perf);
+}
+
+static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
+{
+ int max_perf, min_perf;
+ struct cpufreq_policy *policy;
+
+ policy = per_cpu(cpufreq_cpu_policy, cpu->cpu);
+
+ update_turbo_state();
+
+ if (limits.turbo_disabled)
+ policy->turbo = CPUFREQ_TURBO_UNSUPPORTED;
+ else if (limits.no_turbo)
+ policy->turbo = CPUFREQ_TURBO_DISABLED;
+ else
+ policy->turbo = CPUFREQ_TURBO_ENABLED;
+
+ intel_pstate_get_min_max(cpu, &min_perf, &max_perf);
+
+ pstate = clamp_t(int, pstate, min_perf, max_perf);
+
+ if (pstate == cpu->pstate.current_pstate)
+ return;
+
+ cpu->pstate.current_pstate = pstate;
+ policy->cur = pstate * 100000;
+
+ pstate_funcs.set(cpu, pstate);
+}
+
+static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
+{
+ cpu->pstate.min_pstate = pstate_funcs.get_min();
+ cpu->pstate.max_pstate = pstate_funcs.get_max();
+ cpu->pstate.turbo_pstate = pstate_funcs.get_turbo();
+ cpu->pstate.scaling = pstate_funcs.get_scaling();
+
+ if (pstate_funcs.get_vid)
+ pstate_funcs.get_vid(cpu);
+ intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
+}
+
+static inline void intel_pstate_calc_busy(struct cpudata *cpu)
+{
+ struct sample *sample = &cpu->sample;
+ int64_t core_pct;
+
+ core_pct = int_tofp(sample->aperf) * int_tofp(100);
+ core_pct = div64_u64(core_pct, int_tofp(sample->mperf));
+
+ sample->freq = fp_toint(
+ mul_fp(int_tofp(
+ cpu->pstate.max_pstate * cpu->pstate.scaling / 100),
+ core_pct));
+
+ sample->core_pct_busy = (int32_t)core_pct;
+}
+
+static inline void intel_pstate_sample(struct cpudata *cpu)
+{
+ u64 aperf, mperf;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ rdmsrl(MSR_IA32_APERF, aperf);
+ rdmsrl(MSR_IA32_MPERF, mperf);
+ local_irq_restore(flags);
+
+ cpu->last_sample_time = cpu->sample.time;
+ cpu->sample.time = get_s_time();
+ cpu->sample.aperf = aperf;
+ cpu->sample.mperf = mperf;
+ cpu->sample.aperf -= cpu->prev_aperf;
+ cpu->sample.mperf -= cpu->prev_mperf;
+
+ intel_pstate_calc_busy(cpu);
+
+ cpu->prev_aperf = aperf;
+ cpu->prev_mperf = mperf;
+}
+
+static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
+{
+ set_timer(&cpu->timer, NOW() + MILLISECS(pid_params.sample_rate_ms));
+}
+
+static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu)
+{
+ int32_t core_busy, max_pstate, current_pstate, sample_ratio;
+ u32 duration_us;
+ u32 sample_time_us;
+
+ /*
+ * core_busy is the ratio of actual performance to max
+ * max_pstate is the max non turbo pstate available
+ * current_pstate was the pstate that was requested during
+ * the last sample period.
+ *
+ * We normalize core_busy, which was our actual percent
+ * performance to what we requested during the last sample
+ * period. The result will be a percentage of busy at a
+ * specified pstate.
+ */
+ core_busy = cpu->sample.core_pct_busy;
+ max_pstate = int_tofp(cpu->pstate.max_pstate);
+ current_pstate = int_tofp(cpu->pstate.current_pstate);
+ core_busy = mul_fp(core_busy, div_fp(max_pstate, current_pstate));
+
+ /*
+ * Since we have a deferred timer, it will not fire unless
+ * we are in C0. So, determine if the actual elapsed time
+ * is significantly greater (3x) than our sample interval. If it
+ * is, then we were idle for a long enough period of time
+ * to adjust our busyness.
+ */
+ sample_time_us = pid_params.sample_rate_ms * 1000ULL;
+ duration_us = (u32)((s_time_t)(cpu->sample.time - cpu->last_sample_time)
+ / 1000);
+ if (duration_us > sample_time_us * 3) {
+ sample_ratio = div_fp(int_tofp(sample_time_us),
+ int_tofp(duration_us));
+ core_busy = mul_fp(core_busy, sample_ratio);
+ }
+
+ return core_busy;
+}
+
+static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
+{
+ int32_t busy_scaled;
+ struct _pid *pid;
+ signed int ctl;
+
+ pid = &cpu->pid;
+ busy_scaled = intel_pstate_get_scaled_busy(cpu);
+
+ ctl = pid_calc(pid, busy_scaled);
+
+ /* Negative values of ctl increase the pstate and vice versa */
+ intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl);
+}
+
+static void intel_pstate_timer_func(void *__data)
+{
+ struct cpudata *cpu = (struct cpudata *) __data;
+
+ intel_pstate_sample(cpu);
+
+ intel_pstate_adjust_busy_pstate(cpu);
+
+ intel_pstate_set_sample_time(cpu);
+}
+
+#define ICPU(model, policy) \
+ { X86_VENDOR_INTEL, 6, model, X86_FEATURE_APERFMPERF,\
+ (unsigned long)&policy }
+
+static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
+ ICPU(0x2a, core_params),
+ ICPU(0x2d, core_params),
+ ICPU(0x37, byt_params),
+ ICPU(0x3a, core_params),
+ ICPU(0x3c, core_params),
+ ICPU(0x3d, core_params),
+ ICPU(0x3e, core_params),
+ ICPU(0x3f, core_params),
+ ICPU(0x45, core_params),
+ ICPU(0x46, core_params),
+ ICPU(0x47, core_params),
+ ICPU(0x4c, byt_params),
+ ICPU(0x4e, core_params),
+ ICPU(0x4f, core_params),
+ ICPU(0x56, core_params),
+ {}
+};
+
+static int intel_pstate_init_cpu(unsigned int cpunum)
+{
+ struct cpudata *cpu;
+ s_time_t expires;
+
+ if (!all_cpu_data[cpunum])
+ all_cpu_data[cpunum] = xzalloc(struct cpudata);
+ if (!all_cpu_data[cpunum])
+ return -ENOMEM;
+
+ cpu = all_cpu_data[cpunum];
+
+ cpu->cpu = cpunum;
+ intel_pstate_get_cpu_pstates(cpu);
+
+ init_timer(&cpu->timer, intel_pstate_timer_func, cpu, cpunum);
+ expires = NOW() + MILLISECS(10);
+
+ intel_pstate_busy_pid_reset(cpu);
+ intel_pstate_sample(cpu);
+
+ set_timer(&cpu->timer, expires);
+
+ return 0;
+}
+
+static int intel_pstate_set_policy(struct cpufreq_policy *policy)
+{
+ if (!policy->cpuinfo.max_freq)
+ return -ENODEV;
+
+ if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
+ limits.no_turbo = 0;
+ limits.max_perf_pct = 100;
+ limits.max_perf = int_tofp(1);
+ limits.min_perf_pct = 100;
+ limits.min_perf = int_tofp(1);
+ policy->max_perf_pct = 100;
+ policy->min_perf_pct = 100;
+ return 0;
+ } else if (policy->policy == CPUFREQ_POLICY_POWERSAVE) {
+ limits.min_perf_pct = limits.min_policy_pct;
+ limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
+ limits.max_perf_pct = limits.min_perf_pct;
+ limits.max_perf = limits.min_perf;
+ policy->min_perf_pct = limits.min_policy_pct;
+ policy->max_perf_pct = policy->min_perf_pct;
+ return 0;
+ } else if (policy->policy == CPUFREQ_POLICY_USERSPACE) {
+ limits.max_perf_pct = max(limits.min_policy_pct, policy->max_perf_pct);
+ limits.max_perf_pct = min(limits.max_policy_pct, limits.max_perf_pct);
+ limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
+ limits.min_perf_pct = limits.max_perf_pct;
+ limits.min_perf = limits.max_perf;
+ policy->max_perf_pct = limits.max_perf_pct;
+ policy->min_perf_pct = limits.max_perf_pct;
+ return 0;
+ } else {
+ limits.min_perf_pct = max(limits.min_policy_pct, policy->min_perf_pct);
+ limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
+ limits.max_perf_pct = min(limits.max_policy_pct, policy->max_perf_pct);
+ limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
+ policy->min_perf_pct = limits.min_perf_pct;
+ policy->max_perf_pct = limits.max_perf_pct;
+ return 0;
+ }
+}
+
+static int intel_pstate_verify_policy(struct cpufreq_policy *policy)
+{
+ cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
+ policy->cpuinfo.max_freq);
+
+ if ( policy->policy != CPUFREQ_POLICY_POWERSAVE &&
+ policy->policy != CPUFREQ_POLICY_PERFORMANCE &&
+ policy->policy != CPUFREQ_POLICY_USERSPACE &&
+ policy->policy != CPUFREQ_POLICY_ONDEMAND )
+ return -EINVAL;
+
+ return 0;
+}
+
+static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
+{
+ int cpu_num = policy->cpu;
+ struct cpudata *cpu = all_cpu_data[cpu_num];
+
+ kill_timer(&all_cpu_data[cpu_num]->timer);
+
+ intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
+
+ return 0;
+}
+
+static int intel_pstate_turbo_update(int cpuid, struct cpufreq_policy *policy)
+{
+ struct cpudata *cpu = all_cpu_data[0];
+
+ update_turbo_state();
+ if (limits.turbo_disabled) {
+ printk("Turbo disabled by BIOS or not supported on processor\n");
+ return -EINVAL;
+ }
+ limits.no_turbo = policy->turbo == CPUFREQ_TURBO_ENABLED ? 0 : 1;
+
+ if (limits.no_turbo)
+ policy->cpuinfo.max_freq =
+ cpu->pstate.max_pstate * cpu->pstate.scaling;
+ else
+ policy->cpuinfo.max_freq =
+ cpu->pstate.turbo_pstate * cpu->pstate.scaling;
+
+ policy->max = clamp_t(unsigned int, policy->max,
+ policy->cpuinfo.min_freq, policy->cpuinfo.max_freq);
+
+ return 0;
+}
+
+static int get_turbo_pct(void)
+{
+ struct cpudata *cpu;
+ int total, no_turbo, turbo_pct;
+ uint32_t turbo_fp;
+
+ cpu = all_cpu_data[0];
+
+ total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
+ no_turbo = cpu->pstate.max_pstate - cpu->pstate.min_pstate + 1;
+ turbo_fp = div_fp(int_tofp(no_turbo), int_tofp(total));
+ turbo_pct = 100 - fp_toint(mul_fp(turbo_fp, int_tofp(100)));
+ return turbo_pct;
+}
+
+static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
+{
+ struct cpudata *cpu;
+ int rc;
+
+ rc = intel_pstate_init_cpu(policy->cpu);
+ if (rc)
+ return rc;
+
+ cpu = all_cpu_data[policy->cpu];
+ if (limits.min_perf_pct == 100 && limits.max_perf_pct == 100)
+ policy->policy = CPUFREQ_POLICY_PERFORMANCE;
+ else
+ policy->policy = CPUFREQ_POLICY_ONDEMAND;
+
+ policy->min = cpu->pstate.min_pstate * cpu->pstate.scaling;
+ policy->max = cpu->pstate.turbo_pstate * cpu->pstate.scaling;
+ policy->min_perf_pct = 0;
+ policy->max_perf_pct = 100;
+ policy->turbo_pct = get_turbo_pct();
+
+ /* cpuinfo and default policy values */
+ policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling;
+ policy->cpuinfo.max_freq =
+ cpu->pstate.turbo_pstate * cpu->pstate.scaling;
+ policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+ cpumask_set_cpu(policy->cpu, policy->cpus);
+
+ /* the first cpu do the init work for limits.min/max_policy_pct */
+ if (cpu->cpu == 0) {
+ limits.min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
+ limits.min_policy_pct = clamp_t(int, limits.min_policy_pct, 0, 100);
+ limits.max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq;
+ limits.max_policy_pct = clamp_t(int, limits.max_policy_pct, 0, 100);
+ }
+
+ return 0;
+}
+
+static struct cpufreq_driver intel_pstate_driver = {
+ .verify = intel_pstate_verify_policy,
+ .setpolicy = intel_pstate_set_policy,
+ .init = intel_pstate_cpu_init,
+ .exit = intel_pstate_cpu_exit,
+ .update = intel_pstate_turbo_update,
+ .name = "intel_pstate",
+};
+
+static int intel_pstate_msrs_not_valid(void)
+{
+ /* Check that all the msr's we are using are valid. */
+ u64 aperf, mperf, tmp;
+
+ rdmsrl(MSR_IA32_APERF, aperf);
+ rdmsrl(MSR_IA32_MPERF, mperf);
+
+ if (!pstate_funcs.get_max() ||
+ !pstate_funcs.get_min() ||
+ !pstate_funcs.get_turbo())
+ return -ENODEV;
+
+ rdmsrl(MSR_IA32_APERF, tmp);
+ if (!(tmp - aperf))
+ return -ENODEV;
+
+ rdmsrl(MSR_IA32_MPERF, tmp);
+ if (!(tmp - mperf))
+ return -ENODEV;
+
+ return 0;
+}
+
+static void copy_pid_params(struct pstate_adjust_policy *policy)
+{
+ pid_params.sample_rate_ms = policy->sample_rate_ms;
+ pid_params.p_gain_pct = policy->p_gain_pct;
+ pid_params.i_gain_pct = policy->i_gain_pct;
+ pid_params.d_gain_pct = policy->d_gain_pct;
+ pid_params.deadband = policy->deadband;
+ pid_params.setpoint = policy->setpoint;
+}
+
+static void copy_cpu_funcs(struct pstate_funcs *funcs)
+{
+ pstate_funcs.get_max = funcs->get_max;
+ pstate_funcs.get_min = funcs->get_min;
+ pstate_funcs.get_turbo = funcs->get_turbo;
+ pstate_funcs.get_scaling = funcs->get_scaling;
+ pstate_funcs.set = funcs->set;
+ pstate_funcs.get_vid = funcs->get_vid;
+}
+
+int __init intel_pstate_init(void)
+{
+ int cpu, rc = 0;
+ const struct x86_cpu_id *id;
+ struct cpu_defaults *cpu_info;
+
+ if (cpuid_ecx(6) & 0x1)
+ set_bit(X86_FEATURE_APERFMPERF, &boot_cpu_data.x86_capability);
+
+ id = x86_match_cpu(intel_pstate_cpu_ids);
+ if (!id)
+ return -ENODEV;
+
+ cpu_info = (struct cpu_defaults *)id->driver_data;
+
+ copy_pid_params(&cpu_info->pid_policy);
+ copy_cpu_funcs(&cpu_info->funcs);
+
+ if (intel_pstate_msrs_not_valid())
+ return -ENODEV;
+
+ all_cpu_data = xzalloc_array(struct cpudata *, num_online_cpus());
+ if (!all_cpu_data)
+ return -ENOMEM;
+
+ rc = cpufreq_register_driver(&intel_pstate_driver);
+ if (rc)
+ goto out;
+
+ return rc;
+out:
+ for_each_online_cpu(cpu) {
+ if (all_cpu_data[cpu]) {
+ kill_timer(&all_cpu_data[cpu]->timer);
+ xfree(all_cpu_data[cpu]);
+ }
+ }
+ xfree(all_cpu_data);
+ return -ENODEV;
+}
diff --git a/xen/include/acpi/cpufreq/cpufreq.h
b/xen/include/acpi/cpufreq/cpufreq.h
index 85a055f..abda363 100644
--- a/xen/include/acpi/cpufreq/cpufreq.h
+++ b/xen/include/acpi/cpufreq/cpufreq.h
@@ -34,6 +34,12 @@ struct acpi_cpufreq_data {
extern struct acpi_cpufreq_data *cpufreq_drv_data[NR_CPUS];
+/*
+ * Maximum transition latency is in nanoseconds - if it's unknown,
+ * CPUFREQ_ETERNAL shall be used.
+ */
+#define CPUFREQ_ETERNAL (-1)
+
struct cpufreq_cpuinfo {
unsigned int max_freq;
unsigned int second_max_freq; /* P1 if Turbo Mode is on */
diff --git a/xen/include/asm-x86/acpi.h b/xen/include/asm-x86/acpi.h
index 5e85b38..505d7e7 100644
--- a/xen/include/asm-x86/acpi.h
+++ b/xen/include/asm-x86/acpi.h
@@ -32,6 +32,8 @@
#define COMPILER_DEPENDENT_INT64 long long
#define COMPILER_DEPENDENT_UINT64 unsigned long long
+extern int intel_pstate_init(void);
+
/*
* Calling conventions:
*
diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h
index 7963a3a..efc9711 100644
--- a/xen/include/asm-x86/cpufeature.h
+++ b/xen/include/asm-x86/cpufeature.h
@@ -69,6 +69,7 @@
#define X86_FEATURE_XTOPOLOGY (3*32+13) /* cpu topology enum extensions */
#define X86_FEATURE_CPUID_FAULTING (3*32+14) /* cpuid faulting */
#define X86_FEATURE_CLFLUSH_MONITOR (3*32+15) /* clflush reqd with monitor */
+#define X86_FEATURE_APERFMPERF (3*32+28) /* APERFMPERF */
/* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
#define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */
diff --git a/xen/include/asm-x86/msr-index.h b/xen/include/asm-x86/msr-index.h
index 83f2f70..57945d9 100644
--- a/xen/include/asm-x86/msr-index.h
+++ b/xen/include/asm-x86/msr-index.h
@@ -52,6 +52,8 @@
#define MSR_IA32_MCG_STATUS 0x0000017a
#define MSR_IA32_MCG_CTL 0x0000017b
+#define MSR_NHM_TURBO_RATIO_LIMIT 0x000001ad
+
#define MSR_IA32_PEBS_ENABLE 0x000003f1
#define MSR_IA32_DS_AREA 0x00000600
#define MSR_IA32_PERF_CAPABILITIES 0x00000345
@@ -319,6 +321,7 @@
#define MSR_IA32_MISC_ENABLE_MONITOR_ENABLE (1<<18)
#define MSR_IA32_MISC_ENABLE_LIMIT_CPUID (1<<22)
#define MSR_IA32_MISC_ENABLE_XTPR_DISABLE (1<<23)
+#define MSR_IA32_MISC_ENABLE_TURBO_DISABLE (1ULL<<38)
#define MSR_IA32_TSC_DEADLINE 0x000006E0
#define MSR_IA32_ENERGY_PERF_BIAS 0x000001b0
--
1.9.1
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