>From 507b896942045c0df3073960922c9d5d88b8fa2c Mon Sep 17 00:00:00 2001
From: Vishwesh M Rudramuni <vishwesh.m.rudramuni@xxxxxxxxx>
Date: Thu, 2 Feb 2012 16:07:31 +0530
Subject: [PATCH] [CPUFREQ] sfi based p-state driver
This is the sfi p-state driver for all the intel soc platforms.
This is based on the acpi p-state driver.This patch is generated
against linux 3.2.2.
Signed-off-by: Vishwesh M Rudramuni <vishwesh.m.rudramuni@xxxxxxxxx>
Acked-by: Len Brown <len.brown@xxxxxxxxx>
Reviewed-by: Hari Sesadri <harinarayanan.sesadri@xxxxxxxxx>
Reviewed-by: Rajeev D Muralidhar <rajeev.d.muralidhar@xxxxxxxxx>
---
drivers/cpufreq/Kconfig.x86 | 15 ++
drivers/cpufreq/Makefile | 1 +
drivers/cpufreq/sfi-cpufreq.c | 529 +++++++++++++++++++++++++++++++++++++++++
drivers/cpufreq/sfi-cpufreq.h | 65 +++++
4 files changed, 610 insertions(+), 0 deletions(-)
create mode 100644 drivers/cpufreq/sfi-cpufreq.c
create mode 100644 drivers/cpufreq/sfi-cpufreq.h
diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86
index 78ff7ee..7c53591 100644
--- a/drivers/cpufreq/Kconfig.x86
+++ b/drivers/cpufreq/Kconfig.x86
@@ -32,6 +32,21 @@ config X86_ACPI_CPUFREQ
If in doubt, say N.
+config X86_SFI_CPUFREQ
+ tristate "SFI Processor P-States driver"
+ select CPU_FREQ_TABLE
+ help
+ This driver adds a CPUFreq driver which utilizes the SFI
+ Processor Performance States.
+ This driver also supports Intel Enhanced Speedstep.
+
+ To compile this driver as a module, choose M here: the
+ module will be called sfi-cpufreq.
+
+ For details, take a look at <file:Documentation/cpu-freq/>.
+
+ If in doubt, say N.
+
config ELAN_CPUFREQ
tristate "AMD Elan SC400 and SC410"
select CPU_FREQ_TABLE
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index a48bc02..5ac8987 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_CPU_FREQ_TABLE) += freq_table.o
obj-$(CONFIG_X86_POWERNOW_K8) += powernow-k8.o mperf.o
obj-$(CONFIG_X86_ACPI_CPUFREQ) += acpi-cpufreq.o mperf.o
+obj-$(CONFIG_X86_ACPI_CPUFREQ) += sfi-cpufreq.o mperf.o
obj-$(CONFIG_X86_PCC_CPUFREQ) += pcc-cpufreq.o
obj-$(CONFIG_X86_POWERNOW_K6) += powernow-k6.o
obj-$(CONFIG_X86_POWERNOW_K7) += powernow-k7.o
diff --git a/drivers/cpufreq/sfi-cpufreq.c b/drivers/cpufreq/sfi-cpufreq.c
new file mode 100644
index 0000000..591d41e
--- /dev/null
+++ b/drivers/cpufreq/sfi-cpufreq.c
@@ -0,0 +1,529 @@
+/*
+ * sfi_cpufreq.c - sfi Processor P-States Driver
+ *
+ * (C) 2010-2011 Intel Corporation
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * Author: Vishwesh M Rudramuni
+ * Contact information: Vishwesh Rudramuni <vishwesh.m.rudramuni@xxxxxxxxx>
+ */
+
+/*
+ * This sfi Processor P-States Driver re-uses most part of the code available
+ * in acpi cpufreq driver.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/sched.h>
+#include <linux/cpufreq.h>
+#include <linux/compiler.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <linux/sfi.h>
+#include <linux/io.h>
+
+#include <asm/msr.h>
+#include <asm/processor.h>
+#include <asm/cpufeature.h>
+
+#include "sfi-cpufreq.h"
+#include "mperf.h"
+
+MODULE_AUTHOR("Vishwesh Rudramuni");
+MODULE_DESCRIPTION("SFI Processor P-States Driver");
+MODULE_LICENSE("GPL");
+
+DEFINE_PER_CPU(struct sfi_processor *, sfi_processors);
+
+static DEFINE_MUTEX(performance_mutex);
+static int sfi_cpufreq_num;
+static u32 sfi_cpu_num;
+
+#define SFI_FREQ_MAX 32
+#define INTEL_MSR_RANGE (0xffff)
+#define SFI_CPU_MAX 8
+
+
+struct sfi_cpufreq_data {
+ struct sfi_processor_performance *sfi_data;
+ struct cpufreq_frequency_table *freq_table;
+ unsigned int max_freq;
+ unsigned int resume;
+};
+
+static DEFINE_PER_CPU(struct sfi_cpufreq_data *, drv_data);
+struct sfi_freq_table_entry sfi_cpufreq_array[SFI_FREQ_MAX];
+static struct sfi_cpu_table_entry sfi_cpu_array[SFI_CPU_MAX];
+
+/* sfi_perf_data is a pointer to percpu data. */
+static struct sfi_processor_performance *sfi_perf_data;
+
+static struct cpufreq_driver sfi_cpufreq_driver;
+
+static int parse_freq(struct sfi_table_header *table)
+{
+ struct sfi_table_simple *sb;
+ struct sfi_freq_table_entry *pentry;
+ int totallen;
+
+ sb = (struct sfi_table_simple *)table;
+ if (!sb) {
+ printk(KERN_WARNING "SFI: Unable to map FREQ\n");
+ return -ENODEV;
+ }
+
+ if (!sfi_cpufreq_num) {
+ sfi_cpufreq_num = SFI_GET_NUM_ENTRIES(sb,
+ struct sfi_freq_table_entry);
+ pentry = (struct sfi_freq_table_entry *)sb->pentry;
+ totallen = sfi_cpufreq_num * sizeof(*pentry);
+ memcpy(sfi_cpufreq_array, pentry, totallen);
+ }
+
+ return 0;
+}
+
+static int sfi_processor_get_performance_states(struct sfi_processor *pr)
+{
+ int result = 0;
+ int i;
+
+ pr->performance->state_count = sfi_cpufreq_num;
+ pr->performance->states =
+ kmalloc(sizeof(struct sfi_processor_px) * sfi_cpufreq_num,
+ GFP_KERNEL);
+ if (!pr->performance->states)
+ result = -ENOMEM;
+
+ printk(KERN_INFO "Num p-states %d\n", sfi_cpufreq_num);
+
+ /* Populate the P-states info from the SFI table here */
+ for (i = 0; i < sfi_cpufreq_num; i++) {
+ pr->performance->states[i].core_frequency = \
+ sfi_cpufreq_array[i].freq_mhz;
+ pr->performance->states[i].transition_latency = \
+ sfi_cpufreq_array[i].latency;
+ pr->performance->states[i].control = \
+ sfi_cpufreq_array[i].ctrl_val;
+ printk(KERN_INFO "State [%d]: core_frequency[%d] transition_latency[%d] control[0x%x]\n",
+ i,
+ (u32) pr->performance->states[i].core_frequency,
+ (u32) pr->performance->states[i].transition_latency,
+ (u32) pr->performance->states[i].control);
+ }
+
+ return result;
+}
+
+static int sfi_processor_register_performance(struct sfi_processor_performance
+ *performance, unsigned int cpu)
+{
+ struct sfi_processor *pr;
+
+ mutex_lock(&performance_mutex);
+
+ pr = per_cpu(sfi_processors, cpu);
+ if (!pr) {
+ mutex_unlock(&performance_mutex);
+ return -ENODEV;
+ }
+
+ if (pr->performance) {
+ mutex_unlock(&performance_mutex);
+ return -EBUSY;
+ }
+
+ WARN_ON(!performance);
+
+ pr->performance = performance;
+
+ /* parse the freq table from sfi */
+ sfi_cpufreq_num = 0;
+ sfi_table_parse(SFI_SIG_FREQ, NULL, NULL, parse_freq);
+
+ sfi_processor_get_performance_states(pr);
+
+ mutex_unlock(&performance_mutex);
+ return 0;
+}
+
+void sfi_processor_unregister_performance(struct sfi_processor_performance
+ *performance, unsigned int cpu)
+{
+ struct sfi_processor *pr;
+
+
+ mutex_lock(&performance_mutex);
+
+ pr = per_cpu(sfi_processors, cpu);
+ if (!pr) {
+ mutex_unlock(&performance_mutex);
+ return;
+ }
+
+ if (pr->performance)
+ kfree(pr->performance->states);
+ pr->performance = NULL;
+
+ mutex_unlock(&performance_mutex);
+
+ return;
+}
+
+static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
+{
+ struct sfi_cpufreq_data *data = per_cpu(drv_data, cpu);
+ unsigned int cached_freq;
+
+ pr_debug("get_cur_freq_on_cpu (%d)\n", cpu);
+
+ if (unlikely(data == NULL ||
+ data->sfi_data == NULL || data->freq_table == NULL)) {
+ return 0;
+ }
+
+ cached_freq = data->freq_table[data->sfi_data->state].frequency;
+
+ return cached_freq;
+}
+
+static int sfi_cpufreq_target(struct cpufreq_policy *policy,
+ unsigned int target_freq, unsigned int relation)
+{
+ struct sfi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
+ struct sfi_processor_performance *perf;
+ struct cpufreq_freqs freqs;
+ unsigned int next_state = 0; /* Index into freq_table */
+ unsigned int next_perf_state = 0; /* Index into perf table */
+ int result = 0;
+ u32 lo, hi;
+
+ pr_debug("sfi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
+
+ if (unlikely(data == NULL ||
+ data->sfi_data == NULL || data->freq_table == NULL)) {
+ return -ENODEV;
+ }
+
+ perf = data->sfi_data;
+ result = cpufreq_frequency_table_target(policy,
+ data->freq_table,
+ target_freq,
+ relation, &next_state);
+ if (unlikely(result))
+ return -ENODEV;
+
+ next_perf_state = data->freq_table[next_state].index;
+ if (perf->state == next_perf_state) {
+ if (unlikely(data->resume)) {
+ pr_debug("Called after resume, resetting to P%d\n",
+ next_perf_state);
+ data->resume = 0;
+ } else {
+ pr_debug("Already at target state (P%d)\n",
+ next_perf_state);
+ return 0;
+ }
+ }
+
+ freqs.old = perf->states[perf->state].core_frequency * 1000;
+ freqs.new = data->freq_table[next_state].frequency;
+ freqs.cpu = policy->cpu;
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+ rdmsr_on_cpu(policy->cpu, MSR_IA32_PERF_CTL, &lo, &hi);
+ lo = (lo & ~INTEL_MSR_RANGE) |
+ ((u32) perf->states[next_perf_state].control & INTEL_MSR_RANGE);
+ wrmsr_on_cpu(policy->cpu, MSR_IA32_PERF_CTL, lo, hi);
+
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+ perf->state = next_perf_state;
+
+ return result;
+}
+
+static int sfi_cpufreq_verify(struct cpufreq_policy *policy)
+{
+ struct sfi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
+
+ pr_debug("sfi_cpufreq_verify\n");
+
+ return cpufreq_frequency_table_verify(policy, data->freq_table);
+}
+
+/*
+ * sfi_cpufreq_early_init - initialize SFI P-States library
+ *
+ * Initialize the SFI P-States library (drivers/sfi/processor_perflib.c)
+ * in order to cope with the correct frequency and voltage pairings.
+ */
+static int __init sfi_cpufreq_early_init(void)
+{
+ sfi_perf_data = alloc_percpu(struct sfi_processor_performance);
+ if (!sfi_perf_data) {
+ pr_debug("Memory allocation error for sfi_perf_data.\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+
+static int sfi_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+ unsigned int i;
+ unsigned int valid_states = 0;
+ unsigned int cpu = policy->cpu;
+ struct sfi_cpufreq_data *data;
+ unsigned int result = 0;
+ struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
+ struct sfi_processor_performance *perf;
+
+ pr_debug("sfi_cpufreq_cpu_init CPU:%d\n", policy->cpu);
+
+ data = kzalloc(sizeof(struct sfi_cpufreq_data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->sfi_data = per_cpu_ptr(sfi_perf_data, cpu);
+ per_cpu(drv_data, cpu) = data;
+
+ sfi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
+
+
+ result = sfi_processor_register_performance(data->sfi_data, cpu);
+ if (result)
+ goto err_free;
+
+ perf = data->sfi_data;
+ policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
+
+ cpumask_set_cpu(policy->cpu, policy->cpus);
+ cpumask_set_cpu(policy->cpu, policy->related_cpus);
+
+ /* capability check */
+ if (perf->state_count <= 1) {
+ pr_debug("No P-States\n");
+ result = -ENODEV;
+ goto err_unreg;
+ }
+
+ data->freq_table = kzalloc(sizeof(struct cpufreq_frequency_table) *
+ (perf->state_count+1), GFP_KERNEL);
+ if (!data->freq_table) {
+ result = -ENOMEM;
+ goto err_unreg;
+ }
+
+ /* detect transition latency */
+ policy->cpuinfo.transition_latency = 0;
+ for (i = 0; i < perf->state_count; i++) {
+ if ((perf->states[i].transition_latency * 1000) >
+ policy->cpuinfo.transition_latency)
+ policy->cpuinfo.transition_latency =
+ perf->states[i].transition_latency * 1000;
+ }
+
+ data->max_freq = perf->states[0].core_frequency * 1000;
+ /* table init */
+ for (i = 0; i < perf->state_count; i++) {
+ if (i > 0 && perf->states[i].core_frequency >=
+ data->freq_table[valid_states-1].frequency / 1000)
+ continue;
+
+ data->freq_table[valid_states].index = i;
+ data->freq_table[valid_states].frequency =
+ perf->states[i].core_frequency * 1000;
+ valid_states++;
+ }
+ data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
+ perf->state = 0;
+
+ result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
+ if (result)
+ goto err_freqfree;
+
+ sfi_cpufreq_driver.get = get_cur_freq_on_cpu;
+ policy->cur = get_cur_freq_on_cpu(cpu);
+
+
+ /* Check for APERF/MPERF support in hardware */
+ if (cpu_has(c, X86_FEATURE_APERFMPERF))
+ sfi_cpufreq_driver.getavg = cpufreq_get_measured_perf;
+
+ pr_debug("CPU%u - SFI performance management activated.\n", cpu);
+ for (i = 0; i < perf->state_count; i++)
+ pr_debug(" %cP%d: %d MHz, %d uS\n",
+ (i == perf->state ? '*' : ' '), i,
+ (u32) perf->states[i].core_frequency,
+ (u32) perf->states[i].transition_latency);
+
+ cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
+
+ /*
+ * the first call to ->target() should result in us actually
+ * writing something to the appropriate registers.
+ */
+ data->resume = 1;
+
+ return result;
+
+err_freqfree:
+ kfree(data->freq_table);
+err_unreg:
+ sfi_processor_unregister_performance(perf, cpu);
+err_free:
+ kfree(data);
+ per_cpu(drv_data, cpu) = NULL;
+
+ return result;
+}
+
+static int sfi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+ struct sfi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
+
+ pr_debug("sfi_cpufreq_cpu_exit\n");
+
+ if (data) {
+ cpufreq_frequency_table_put_attr(policy->cpu);
+ per_cpu(drv_data, policy->cpu) = NULL;
+ sfi_processor_unregister_performance(data->sfi_data,
+ policy->cpu);
+ kfree(data);
+ }
+
+ return 0;
+}
+
+static int sfi_cpufreq_resume(struct cpufreq_policy *policy)
+{
+ struct sfi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
+
+ pr_debug("sfi_cpufreq_resume\n");
+
+ data->resume = 1;
+
+ return 0;
+}
+
+static struct freq_attr *sfi_cpufreq_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ NULL,
+};
+
+static struct cpufreq_driver sfi_cpufreq_driver = {
+ .verify = sfi_cpufreq_verify,
+ .target = sfi_cpufreq_target,
+ .init = sfi_cpufreq_cpu_init,
+ .exit = sfi_cpufreq_cpu_exit,
+ .resume = sfi_cpufreq_resume,
+ .name = "sfi-cpufreq",
+ .owner = THIS_MODULE,
+ .attr = sfi_cpufreq_attr,
+};
+
+static int __init parse_cpus(struct sfi_table_header *table)
+{
+ struct sfi_table_simple *sb;
+ struct sfi_cpu_table_entry *pentry;
+ int i;
+
+ sb = (struct sfi_table_simple *)table;
+
+ sfi_cpu_num = SFI_GET_NUM_ENTRIES(sb, struct sfi_cpu_table_entry);
+
+ pentry = (struct sfi_cpu_table_entry *) sb->pentry;
+ for (i = 0; i < sfi_cpu_num; i++) {
+ sfi_cpu_array[i].apic_id = pentry->apic_id;
+ printk(KERN_INFO "APIC ID: %d\n", pentry->apic_id);
+ pentry++;
+ }
+
+ return 0;
+
+}
+
+
+static int __init init_sfi_processor_list(void)
+{
+ struct sfi_processor *pr;
+ int i;
+ int result;
+
+ /* parse the cpus from the sfi table */
+ result = sfi_table_parse(SFI_SIG_CPUS, NULL, NULL, parse_cpus);
+
+ if (result < 0)
+ return result;
+
+ pr = kzalloc(sfi_cpu_num * sizeof(struct sfi_processor), GFP_KERNEL);
+ if (!pr)
+ return -ENOMEM;
+
+ for (i = 0; i < sfi_cpu_num; i++) {
+ pr->id = sfi_cpu_array[i].apic_id;
+ per_cpu(sfi_processors, pr->id) = pr;
+ pr++;
+ }
+
+ return 0;
+}
+
+static int __init sfi_cpufreq_init(void)
+{
+ int ret;
+
+ pr_debug("sfi_cpufreq_init\n");
+
+ ret = init_sfi_processor_list();
+ if (ret)
+ return ret;
+
+ ret = sfi_cpufreq_early_init();
+ if (ret)
+ return ret;
+
+ return cpufreq_register_driver(&sfi_cpufreq_driver);
+}
+
+static void __exit sfi_cpufreq_exit(void)
+{
+
+ struct sfi_processor *pr;
+
+ pr_debug("sfi_cpufreq_exit\n");
+
+ pr = per_cpu(sfi_processors, 0);
+ kfree(pr);
+
+ cpufreq_unregister_driver(&sfi_cpufreq_driver);
+
+ free_percpu(sfi_perf_data);
+
+ return;
+}
+late_initcall(sfi_cpufreq_init);
+module_exit(sfi_cpufreq_exit);
+
+MODULE_ALIAS("sfi");
diff --git a/drivers/cpufreq/sfi-cpufreq.h b/drivers/cpufreq/sfi-cpufreq.h
new file mode 100644
index 0000000..7e01c1e
--- /dev/null
+++ b/drivers/cpufreq/sfi-cpufreq.h
@@ -0,0 +1,65 @@
+/*
+ * sfi_processor.h
+ * Copyright (c) 2010, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef __SFI_PROCESSOR_H__
+#define __SFI_PROCESSOR_H__
+
+#include <linux/sfi.h>
+#include <linux/cpuidle.h>
+
+struct sfi_processor_power {
+ struct cpuidle_device dev;
+ u32 default_state;
+ int count;
+ struct cpuidle_state *states;
+ struct sfi_cstate_table_entry *sfi_cstates;
+};
+
+struct sfi_processor_flags {
+ u8 valid;
+ u8 power;
+};
+
+struct sfi_processor {
+ u32 id;
+ struct sfi_processor_flags flags;
+ struct sfi_processor_power power;
+ struct sfi_processor_performance *performance;
+};
+
+/* Performance management */
+struct sfi_processor_px {
+ u32 core_frequency; /* megahertz */
+ u32 transition_latency; /* microseconds */
+ u32 control; /* control value */
+};
+
+struct sfi_processor_performance {
+ unsigned int state;
+ unsigned int state_count;
+ struct sfi_processor_px *states;
+};
+
+/* for communication between multiple parts of the processor kernel module */
+DECLARE_PER_CPU(struct sfi_processor *, sfi_processors);
+
+int sfi_processor_power_init(struct sfi_processor *pr);
+int sfi_processor_power_exit(struct sfi_processor *pr);
+
+#endif /*__SFI_PROCESSOR_H__*/
--
1.7.0.4
Attachment:
0001-CPUFREQ-sfi-based-p-state-driver.patch
Description: 0001-CPUFREQ-sfi-based-p-state-driver.patch
