i386: move kernel/cpu/cpufreq

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 634 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c b/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
new file mode 100644
index 00000000000..6c5dc2c85ae
--- /dev/null
+++ b/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
@@ -0,0 +1,634 @@
+/*
+ * cpufreq driver for Enhanced SpeedStep, as found in Intel's Pentium
+ * M (part of the Centrino chipset).
+ *
+ * Since the original Pentium M, most new Intel CPUs support Enhanced
+ * SpeedStep.
+ *
+ * Despite the "SpeedStep" in the name, this is almost entirely unlike
+ * traditional SpeedStep.
+ *
+ * Modelled on speedstep.c
+ *
+ * Copyright (C) 2003 Jeremy Fitzhardinge <jeremy@goop.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/sched.h>	/* current */
+#include <linux/delay.h>
+#include <linux/compiler.h>
+
+#include <asm/msr.h>
+#include <asm/processor.h>
+#include <asm/cpufeature.h>
+
+#define PFX		"speedstep-centrino: "
+#define MAINTAINER	"cpufreq@lists.linux.org.uk"
+
+#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "speedstep-centrino", msg)
+
+#define INTEL_MSR_RANGE	(0xffff)
+
+struct cpu_id
+{
+	__u8	x86;            /* CPU family */
+	__u8	x86_model;	/* model */
+	__u8	x86_mask;	/* stepping */
+};
+
+enum {
+	CPU_BANIAS,
+	CPU_DOTHAN_A1,
+	CPU_DOTHAN_A2,
+	CPU_DOTHAN_B0,
+	CPU_MP4HT_D0,
+	CPU_MP4HT_E0,
+};
+
+static const struct cpu_id cpu_ids[] = {
+	[CPU_BANIAS]	= { 6,  9, 5 },
+	[CPU_DOTHAN_A1]	= { 6, 13, 1 },
+	[CPU_DOTHAN_A2]	= { 6, 13, 2 },
+	[CPU_DOTHAN_B0]	= { 6, 13, 6 },
+	[CPU_MP4HT_D0]	= {15,  3, 4 },
+	[CPU_MP4HT_E0]	= {15,  4, 1 },
+};
+#define N_IDS	ARRAY_SIZE(cpu_ids)
+
+struct cpu_model
+{
+	const struct cpu_id *cpu_id;
+	const char	*model_name;
+	unsigned	max_freq; /* max clock in kHz */
+
+	struct cpufreq_frequency_table *op_points; /* clock/voltage pairs */
+};
+static int centrino_verify_cpu_id(const struct cpuinfo_x86 *c, const struct cpu_id *x);
+
+/* Operating points for current CPU */
+static struct cpu_model *centrino_model[NR_CPUS];
+static const struct cpu_id *centrino_cpu[NR_CPUS];
+
+static struct cpufreq_driver centrino_driver;
+
+#ifdef CONFIG_X86_SPEEDSTEP_CENTRINO_TABLE
+
+/* Computes the correct form for IA32_PERF_CTL MSR for a particular
+   frequency/voltage operating point; frequency in MHz, volts in mV.
+   This is stored as "index" in the structure. */
+#define OP(mhz, mv)							\
+	{								\
+		.frequency = (mhz) * 1000,				\
+		.index = (((mhz)/100) << 8) | ((mv - 700) / 16)		\
+	}
+
+/*
+ * These voltage tables were derived from the Intel Pentium M
+ * datasheet, document 25261202.pdf, Table 5.  I have verified they
+ * are consistent with my IBM ThinkPad X31, which has a 1.3GHz Pentium
+ * M.
+ */
+
+/* Ultra Low Voltage Intel Pentium M processor 900MHz (Banias) */
+static struct cpufreq_frequency_table banias_900[] =
+{
+	OP(600,  844),
+	OP(800,  988),
+	OP(900, 1004),
+	{ .frequency = CPUFREQ_TABLE_END }
+};
+
+/* Ultra Low Voltage Intel Pentium M processor 1000MHz (Banias) */
+static struct cpufreq_frequency_table banias_1000[] =
+{
+	OP(600,   844),
+	OP(800,   972),
+	OP(900,   988),
+	OP(1000, 1004),
+	{ .frequency = CPUFREQ_TABLE_END }
+};
+
+/* Low Voltage Intel Pentium M processor 1.10GHz (Banias) */
+static struct cpufreq_frequency_table banias_1100[] =
+{
+	OP( 600,  956),
+	OP( 800, 1020),
+	OP( 900, 1100),
+	OP(1000, 1164),
+	OP(1100, 1180),
+	{ .frequency = CPUFREQ_TABLE_END }
+};
+
+
+/* Low Voltage Intel Pentium M processor 1.20GHz (Banias) */
+static struct cpufreq_frequency_table banias_1200[] =
+{
+	OP( 600,  956),
+	OP( 800, 1004),
+	OP( 900, 1020),
+	OP(1000, 1100),
+	OP(1100, 1164),
+	OP(1200, 1180),
+	{ .frequency = CPUFREQ_TABLE_END }
+};
+
+/* Intel Pentium M processor 1.30GHz (Banias) */
+static struct cpufreq_frequency_table banias_1300[] =
+{
+	OP( 600,  956),
+	OP( 800, 1260),
+	OP(1000, 1292),
+	OP(1200, 1356),
+	OP(1300, 1388),
+	{ .frequency = CPUFREQ_TABLE_END }
+};
+
+/* Intel Pentium M processor 1.40GHz (Banias) */
+static struct cpufreq_frequency_table banias_1400[] =
+{
+	OP( 600,  956),
+	OP( 800, 1180),
+	OP(1000, 1308),
+	OP(1200, 1436),
+	OP(1400, 1484),
+	{ .frequency = CPUFREQ_TABLE_END }
+};
+
+/* Intel Pentium M processor 1.50GHz (Banias) */
+static struct cpufreq_frequency_table banias_1500[] =
+{
+	OP( 600,  956),
+	OP( 800, 1116),
+	OP(1000, 1228),
+	OP(1200, 1356),
+	OP(1400, 1452),
+	OP(1500, 1484),
+	{ .frequency = CPUFREQ_TABLE_END }
+};
+
+/* Intel Pentium M processor 1.60GHz (Banias) */
+static struct cpufreq_frequency_table banias_1600[] =
+{
+	OP( 600,  956),
+	OP( 800, 1036),
+	OP(1000, 1164),
+	OP(1200, 1276),
+	OP(1400, 1420),
+	OP(1600, 1484),
+	{ .frequency = CPUFREQ_TABLE_END }
+};
+
+/* Intel Pentium M processor 1.70GHz (Banias) */
+static struct cpufreq_frequency_table banias_1700[] =
+{
+	OP( 600,  956),
+	OP( 800, 1004),
+	OP(1000, 1116),
+	OP(1200, 1228),
+	OP(1400, 1308),
+	OP(1700, 1484),
+	{ .frequency = CPUFREQ_TABLE_END }
+};
+#undef OP
+
+#define _BANIAS(cpuid, max, name)	\
+{	.cpu_id		= cpuid,	\
+	.model_name	= "Intel(R) Pentium(R) M processor " name "MHz", \
+	.max_freq	= (max)*1000,	\
+	.op_points	= banias_##max,	\
+}
+#define BANIAS(max)	_BANIAS(&cpu_ids[CPU_BANIAS], max, #max)
+
+/* CPU models, their operating frequency range, and freq/voltage
+   operating points */
+static struct cpu_model models[] =
+{
+	_BANIAS(&cpu_ids[CPU_BANIAS], 900, " 900"),
+	BANIAS(1000),
+	BANIAS(1100),
+	BANIAS(1200),
+	BANIAS(1300),
+	BANIAS(1400),
+	BANIAS(1500),
+	BANIAS(1600),
+	BANIAS(1700),
+
+	/* NULL model_name is a wildcard */
+	{ &cpu_ids[CPU_DOTHAN_A1], NULL, 0, NULL },
+	{ &cpu_ids[CPU_DOTHAN_A2], NULL, 0, NULL },
+	{ &cpu_ids[CPU_DOTHAN_B0], NULL, 0, NULL },
+	{ &cpu_ids[CPU_MP4HT_D0], NULL, 0, NULL },
+	{ &cpu_ids[CPU_MP4HT_E0], NULL, 0, NULL },
+
+	{ NULL, }
+};
+#undef _BANIAS
+#undef BANIAS
+
+static int centrino_cpu_init_table(struct cpufreq_policy *policy)
+{
+	struct cpuinfo_x86 *cpu = &cpu_data[policy->cpu];
+	struct cpu_model *model;
+
+	for(model = models; model->cpu_id != NULL; model++)
+		if (centrino_verify_cpu_id(cpu, model->cpu_id) &&
+		    (model->model_name == NULL ||
+		     strcmp(cpu->x86_model_id, model->model_name) == 0))
+			break;
+
+	if (model->cpu_id == NULL) {
+		/* No match at all */
+		dprintk("no support for CPU model \"%s\": "
+		       "send /proc/cpuinfo to " MAINTAINER "\n",
+		       cpu->x86_model_id);
+		return -ENOENT;
+	}
+
+	if (model->op_points == NULL) {
+		/* Matched a non-match */
+		dprintk("no table support for CPU model \"%s\"\n",
+		       cpu->x86_model_id);
+		dprintk("try using the acpi-cpufreq driver\n");
+		return -ENOENT;
+	}
+
+	centrino_model[policy->cpu] = model;
+
+	dprintk("found \"%s\": max frequency: %dkHz\n",
+	       model->model_name, model->max_freq);
+
+	return 0;
+}
+
+#else
+static inline int centrino_cpu_init_table(struct cpufreq_policy *policy) { return -ENODEV; }
+#endif /* CONFIG_X86_SPEEDSTEP_CENTRINO_TABLE */
+
+static int centrino_verify_cpu_id(const struct cpuinfo_x86 *c, const struct cpu_id *x)
+{
+	if ((c->x86 == x->x86) &&
+	    (c->x86_model == x->x86_model) &&
+	    (c->x86_mask == x->x86_mask))
+		return 1;
+	return 0;
+}
+
+/* To be called only after centrino_model is initialized */
+static unsigned extract_clock(unsigned msr, unsigned int cpu, int failsafe)
+{
+	int i;
+
+	/*
+	 * Extract clock in kHz from PERF_CTL value
+	 * for centrino, as some DSDTs are buggy.
+	 * Ideally, this can be done using the acpi_data structure.
+	 */
+	if ((centrino_cpu[cpu] == &cpu_ids[CPU_BANIAS]) ||
+	    (centrino_cpu[cpu] == &cpu_ids[CPU_DOTHAN_A1]) ||
+	    (centrino_cpu[cpu] == &cpu_ids[CPU_DOTHAN_B0])) {
+		msr = (msr >> 8) & 0xff;
+		return msr * 100000;
+	}
+
+	if ((!centrino_model[cpu]) || (!centrino_model[cpu]->op_points))
+		return 0;
+
+	msr &= 0xffff;
+	for (i=0;centrino_model[cpu]->op_points[i].frequency != CPUFREQ_TABLE_END; i++) {
+		if (msr == centrino_model[cpu]->op_points[i].index)
+			return centrino_model[cpu]->op_points[i].frequency;
+	}
+	if (failsafe)
+		return centrino_model[cpu]->op_points[i-1].frequency;
+	else
+		return 0;
+}
+
+/* Return the current CPU frequency in kHz */
+static unsigned int get_cur_freq(unsigned int cpu)
+{
+	unsigned l, h;
+	unsigned clock_freq;
+	cpumask_t saved_mask;
+
+	saved_mask = current->cpus_allowed;
+	set_cpus_allowed(current, cpumask_of_cpu(cpu));
+	if (smp_processor_id() != cpu)
+		return 0;
+
+	rdmsr(MSR_IA32_PERF_STATUS, l, h);
+	clock_freq = extract_clock(l, cpu, 0);
+
+	if (unlikely(clock_freq == 0)) {
+		/*
+		 * On some CPUs, we can see transient MSR values (which are
+		 * not present in _PSS), while CPU is doing some automatic
+		 * P-state transition (like TM2). Get the last freq set 
+		 * in PERF_CTL.
+		 */
+		rdmsr(MSR_IA32_PERF_CTL, l, h);
+		clock_freq = extract_clock(l, cpu, 1);
+	}
+
+	set_cpus_allowed(current, saved_mask);
+	return clock_freq;
+}
+
+
+static int centrino_cpu_init(struct cpufreq_policy *policy)
+{
+	struct cpuinfo_x86 *cpu = &cpu_data[policy->cpu];
+	unsigned freq;
+	unsigned l, h;
+	int ret;
+	int i;
+
+	/* Only Intel makes Enhanced Speedstep-capable CPUs */
+	if (cpu->x86_vendor != X86_VENDOR_INTEL || !cpu_has(cpu, X86_FEATURE_EST))
+		return -ENODEV;
+
+	if (cpu_has(cpu, X86_FEATURE_CONSTANT_TSC))
+		centrino_driver.flags |= CPUFREQ_CONST_LOOPS;
+
+	if (policy->cpu != 0)
+		return -ENODEV;
+
+	for (i = 0; i < N_IDS; i++)
+		if (centrino_verify_cpu_id(cpu, &cpu_ids[i]))
+			break;
+
+	if (i != N_IDS)
+		centrino_cpu[policy->cpu] = &cpu_ids[i];
+
+	if (!centrino_cpu[policy->cpu]) {
+		dprintk("found unsupported CPU with "
+		"Enhanced SpeedStep: send /proc/cpuinfo to "
+		MAINTAINER "\n");
+		return -ENODEV;
+	}
+
+	if (centrino_cpu_init_table(policy)) {
+		return -ENODEV;
+	}
+
+	/* Check to see if Enhanced SpeedStep is enabled, and try to
+	   enable it if not. */
+	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
+
+	if (!(l & (1<<16))) {
+		l |= (1<<16);
+		dprintk("trying to enable Enhanced SpeedStep (%x)\n", l);
+		wrmsr(MSR_IA32_MISC_ENABLE, l, h);
+
+		/* check to see if it stuck */
+		rdmsr(MSR_IA32_MISC_ENABLE, l, h);
+		if (!(l & (1<<16))) {
+			printk(KERN_INFO PFX "couldn't enable Enhanced SpeedStep\n");
+			return -ENODEV;
+		}
+	}
+
+	freq = get_cur_freq(policy->cpu);
+
+	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
+	policy->cpuinfo.transition_latency = 10000; /* 10uS transition latency */
+	policy->cur = freq;
+
+	dprintk("centrino_cpu_init: cur=%dkHz\n", policy->cur);
+
+	ret = cpufreq_frequency_table_cpuinfo(policy, centrino_model[policy->cpu]->op_points);
+	if (ret)
+		return (ret);
+
+	cpufreq_frequency_table_get_attr(centrino_model[policy->cpu]->op_points, policy->cpu);
+
+	return 0;
+}
+
+static int centrino_cpu_exit(struct cpufreq_policy *policy)
+{
+	unsigned int cpu = policy->cpu;
+
+	if (!centrino_model[cpu])
+		return -ENODEV;
+
+	cpufreq_frequency_table_put_attr(cpu);
+
+	centrino_model[cpu] = NULL;
+
+	return 0;
+}
+
+/**
+ * centrino_verify - verifies a new CPUFreq policy
+ * @policy: new policy
+ *
+ * Limit must be within this model's frequency range at least one
+ * border included.
+ */
+static int centrino_verify (struct cpufreq_policy *policy)
+{
+	return cpufreq_frequency_table_verify(policy, centrino_model[policy->cpu]->op_points);
+}
+
+/**
+ * centrino_setpolicy - set a new CPUFreq policy
+ * @policy: new policy
+ * @target_freq: the target frequency
+ * @relation: how that frequency relates to achieved frequency (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
+ *
+ * Sets a new CPUFreq policy.
+ */
+static int centrino_target (struct cpufreq_policy *policy,
+			    unsigned int target_freq,
+			    unsigned int relation)
+{
+	unsigned int    newstate = 0;
+	unsigned int	msr, oldmsr = 0, h = 0, cpu = policy->cpu;
+	struct cpufreq_freqs	freqs;
+	cpumask_t		online_policy_cpus;
+	cpumask_t		saved_mask;
+	cpumask_t		set_mask;
+	cpumask_t		covered_cpus;
+	int			retval = 0;
+	unsigned int		j, k, first_cpu, tmp;
+
+	if (unlikely(centrino_model[cpu] == NULL))
+		return -ENODEV;
+
+	if (unlikely(cpufreq_frequency_table_target(policy,
+			centrino_model[cpu]->op_points,
+			target_freq,
+			relation,
+			&newstate))) {
+		return -EINVAL;
+	}
+
+#ifdef CONFIG_HOTPLUG_CPU
+	/* cpufreq holds the hotplug lock, so we are safe from here on */
+	cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
+#else
+	online_policy_cpus = policy->cpus;
+#endif
+
+	saved_mask = current->cpus_allowed;
+	first_cpu = 1;
+	cpus_clear(covered_cpus);
+	for_each_cpu_mask(j, online_policy_cpus) {
+		/*
+		 * Support for SMP systems.
+		 * Make sure we are running on CPU that wants to change freq
+		 */
+		cpus_clear(set_mask);
+		if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
+			cpus_or(set_mask, set_mask, online_policy_cpus);
+		else
+			cpu_set(j, set_mask);
+
+		set_cpus_allowed(current, set_mask);
+		preempt_disable();
+		if (unlikely(!cpu_isset(smp_processor_id(), set_mask))) {
+			dprintk("couldn't limit to CPUs in this domain\n");
+			retval = -EAGAIN;
+			if (first_cpu) {
+				/* We haven't started the transition yet. */
+				goto migrate_end;
+			}
+			preempt_enable();
+			break;
+		}
+
+		msr = centrino_model[cpu]->op_points[newstate].index;
+
+		if (first_cpu) {
+			rdmsr(MSR_IA32_PERF_CTL, oldmsr, h);
+			if (msr == (oldmsr & 0xffff)) {
+				dprintk("no change needed - msr was and needs "
+					"to be %x\n", oldmsr);
+				retval = 0;
+				goto migrate_end;
+			}
+
+			freqs.old = extract_clock(oldmsr, cpu, 0);
+			freqs.new = extract_clock(msr, cpu, 0);
+
+			dprintk("target=%dkHz old=%d new=%d msr=%04x\n",
+				target_freq, freqs.old, freqs.new, msr);
+
+			for_each_cpu_mask(k, online_policy_cpus) {
+				freqs.cpu = k;
+				cpufreq_notify_transition(&freqs,
+					CPUFREQ_PRECHANGE);
+			}
+
+			first_cpu = 0;
+			/* all but 16 LSB are reserved, treat them with care */
+			oldmsr &= ~0xffff;
+			msr &= 0xffff;
+			oldmsr |= msr;
+		}
+
+		wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);
+		if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
+			preempt_enable();
+			break;
+		}
+
+		cpu_set(j, covered_cpus);
+		preempt_enable();
+	}
+
+	for_each_cpu_mask(k, online_policy_cpus) {
+		freqs.cpu = k;
+		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+	}
+
+	if (unlikely(retval)) {
+		/*
+		 * We have failed halfway through the frequency change.
+		 * We have sent callbacks to policy->cpus and
+		 * MSRs have already been written on coverd_cpus.
+		 * Best effort undo..
+		 */
+
+		if (!cpus_empty(covered_cpus)) {
+			for_each_cpu_mask(j, covered_cpus) {
+				set_cpus_allowed(current, cpumask_of_cpu(j));
+				wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);
+			}
+		}
+
+		tmp = freqs.new;
+		freqs.new = freqs.old;
+		freqs.old = tmp;
+		for_each_cpu_mask(j, online_policy_cpus) {
+			freqs.cpu = j;
+			cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+			cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+		}
+	}
+	set_cpus_allowed(current, saved_mask);
+	return 0;
+
+migrate_end:
+	preempt_enable();
+	set_cpus_allowed(current, saved_mask);
+	return 0;
+}
+
+static struct freq_attr* centrino_attr[] = {
+	&cpufreq_freq_attr_scaling_available_freqs,
+	NULL,
+};
+
+static struct cpufreq_driver centrino_driver = {
+	.name		= "centrino", /* should be speedstep-centrino,
+					 but there's a 16 char limit */
+	.init		= centrino_cpu_init,
+	.exit		= centrino_cpu_exit,
+	.verify		= centrino_verify,
+	.target		= centrino_target,
+	.get		= get_cur_freq,
+	.attr           = centrino_attr,
+	.owner		= THIS_MODULE,
+};
+
+
+/**
+ * centrino_init - initializes the Enhanced SpeedStep CPUFreq driver
+ *
+ * Initializes the Enhanced SpeedStep support. Returns -ENODEV on
+ * unsupported devices, -ENOENT if there's no voltage table for this
+ * particular CPU model, -EINVAL on problems during initiatization,
+ * and zero on success.
+ *
+ * This is quite picky.  Not only does the CPU have to advertise the
+ * "est" flag in the cpuid capability flags, we look for a specific
+ * CPU model and stepping, and we need to have the exact model name in
+ * our voltage tables.  That is, be paranoid about not releasing
+ * someone's valuable magic smoke.
+ */
+static int __init centrino_init(void)
+{
+	struct cpuinfo_x86 *cpu = cpu_data;
+
+	if (!cpu_has(cpu, X86_FEATURE_EST))
+		return -ENODEV;
+
+	return cpufreq_register_driver(&centrino_driver);
+}
+
+static void __exit centrino_exit(void)
+{
+	cpufreq_unregister_driver(&centrino_driver);
+}
+
+MODULE_AUTHOR ("Jeremy Fitzhardinge <jeremy@goop.org>");
+MODULE_DESCRIPTION ("Enhanced SpeedStep driver for Intel Pentium M processors.");
+MODULE_LICENSE ("GPL");
+
+late_initcall(centrino_init);
+module_exit(centrino_exit);