powernow-k7.c

linux 内核源代码

/*
 *  AMD K7 Powernow driver.
 *  (C) 2003 Dave Jones <[e-mail]> on behalf of SuSE Labs.
 *  (C) 2003-2004 Dave Jones <[e-mail]>
 *
 *  Licensed under the terms of the GNU GPL License version 2.
 *  Based upon datasheets & sample CPUs kindly provided by AMD.
 *
 * Errata 5: Processor may fail to execute a FID/VID change in presence of interrupt.
 * - We cli/sti on stepping A0 CPUs around the FID/VID transition.
 * Errata 15: Processors with half frequency multipliers may hang upon wakeup from disconnect.
 * - We disable half multipliers if ACPI is used on A0 stepping CPUs.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/dmi.h>

#include <asm/msr.h>
#include <asm/timer.h>
#include <asm/timex.h>
#include <asm/io.h>
#include <asm/system.h>

#ifdef CONFIG_X86_POWERNOW_K7_ACPI
#include <linux/acpi.h>
#include <acpi/processor.h>
#endif

#include "powernow-k7.h"

#define PFX "powernow: "


struct psb_s {
	u8 signature[10];
	u8 tableversion;
	u8 flags;
	u16 settlingtime;
	u8 reserved1;
	u8 numpst;
};

struct pst_s {
	u32 cpuid;
	u8 fsbspeed;
	u8 maxfid;
	u8 startvid;
	u8 numpstates;
};

#ifdef CONFIG_X86_POWERNOW_K7_ACPI
union powernow_acpi_control_t {
	struct {
		unsigned long fid:5,
		vid:5,
		sgtc:20,
		res1:2;
	} bits;
	unsigned long val;
};
#endif

#ifdef CONFIG_CPU_FREQ_DEBUG
/* divide by 1000 to get VCore voltage in V. */
static const int mobile_vid_table[32] = {
    2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650,
    1600, 1550, 1500, 1450, 1400, 1350, 1300, 0,
    1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100,
    1075, 1050, 1025, 1000, 975, 950, 925, 0,
};
#endif

/* divide by 10 to get FID. */
static const int fid_codes[32] = {
    110, 115, 120, 125, 50, 55, 60, 65,
    70, 75, 80, 85, 90, 95, 100, 105,
    30, 190, 40, 200, 130, 135, 140, 210,
    150, 225, 160, 165, 170, 180, -1, -1,
};

/* This parameter is used in order to force ACPI instead of legacy method for
 * configuration purpose.
 */

static int acpi_force;

static struct cpufreq_frequency_table *powernow_table;

static unsigned int can_scale_bus;
static unsigned int can_scale_vid;
static unsigned int minimum_speed=-1;
static unsigned int maximum_speed;
static unsigned int number_scales;
static unsigned int fsb;
static unsigned int latency;
static char have_a0;

#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "powernow-k7", msg)

static int check_fsb(unsigned int fsbspeed)
{
	int delta;
	unsigned int f = fsb / 1000;

	delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed;
	return (delta < 5);
}

static int check_powernow(void)
{
	struct cpuinfo_x86 *c = &cpu_data(0);
	unsigned int maxei, eax, ebx, ecx, edx;

	if ((c->x86_vendor != X86_VENDOR_AMD) || (c->x86 !=6)) {
#ifdef MODULE
		printk (KERN_INFO PFX "This module only works with AMD K7 CPUs\n");
#endif
		return 0;
	}

	/* Get maximum capabilities */
	maxei = cpuid_eax (0x80000000);
	if (maxei < 0x80000007) {	/* Any powernow info ? */
#ifdef MODULE
		printk (KERN_INFO PFX "No powernow capabilities detected\n");
#endif
		return 0;
	}

	if ((c->x86_model == 6) && (c->x86_mask == 0)) {
		printk (KERN_INFO PFX "K7 660[A0] core detected, enabling errata workarounds\n");
		have_a0 = 1;
	}

	cpuid(0x80000007, &eax, &ebx, &ecx, &edx);

	/* Check we can actually do something before we say anything.*/
	if (!(edx & (1 << 1 | 1 << 2)))
		return 0;

	printk (KERN_INFO PFX "PowerNOW! Technology present. Can scale: ");

	if (edx & 1 << 1) {
		printk ("frequency");
		can_scale_bus=1;
	}

	if ((edx & (1 << 1 | 1 << 2)) == 0x6)
		printk (" and ");

	if (edx & 1 << 2) {
		printk ("voltage");
		can_scale_vid=1;
	}

	printk (".\n");
	return 1;
}


static int get_ranges (unsigned char *pst)
{
	unsigned int j;
	unsigned int speed;
	u8 fid, vid;

	powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) * (number_scales + 1)), GFP_KERNEL);
	if (!powernow_table)
		return -ENOMEM;

	for (j=0 ; j < number_scales; j++) {
		fid = *pst++;

		powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10;
		powernow_table[j].index = fid; /* lower 8 bits */

		speed = powernow_table[j].frequency;

		if ((fid_codes[fid] % 10)==5) {
#ifdef CONFIG_X86_POWERNOW_K7_ACPI
			if (have_a0 == 1)
				powernow_table[j].frequency = CPUFREQ_ENTRY_INVALID;
#endif
		}

		if (speed < minimum_speed)
			minimum_speed = speed;
		if (speed > maximum_speed)
			maximum_speed = speed;

		vid = *pst++;
		powernow_table[j].index |= (vid << 8); /* upper 8 bits */

		dprintk ("   FID: 0x%x (%d.%dx [%dMHz])  "
			 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
			 fid_codes[fid] % 10, speed/1000, vid,
			 mobile_vid_table[vid]/1000,
			 mobile_vid_table[vid]%1000);
	}
	powernow_table[number_scales].frequency = CPUFREQ_TABLE_END;
	powernow_table[number_scales].index = 0;

	return 0;
}


static void change_FID(int fid)
{
	union msr_fidvidctl fidvidctl;

	rdmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val);
	if (fidvidctl.bits.FID != fid) {
		fidvidctl.bits.SGTC = latency;
		fidvidctl.bits.FID = fid;
		fidvidctl.bits.VIDC = 0;
		fidvidctl.bits.FIDC = 1;
		wrmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val);
	}
}


static void change_VID(int vid)
{
	union msr_fidvidctl fidvidctl;

	rdmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val);
	if (fidvidctl.bits.VID != vid) {
		fidvidctl.bits.SGTC = latency;
		fidvidctl.bits.VID = vid;
		fidvidctl.bits.FIDC = 0;
		fidvidctl.bits.VIDC = 1;
		wrmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val);
	}
}


static void change_speed (unsigned int index)
{
	u8 fid, vid;
	struct cpufreq_freqs freqs;
	union msr_fidvidstatus fidvidstatus;
	int cfid;

	/* fid are the lower 8 bits of the index we stored into
	 * the cpufreq frequency table in powernow_decode_bios,
	 * vid are the upper 8 bits.
	 */

	fid = powernow_table[index].index & 0xFF;
	vid = (powernow_table[index].index & 0xFF00) >> 8;

	freqs.cpu = 0;

	rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val);
	cfid = fidvidstatus.bits.CFID;
	freqs.old = fsb * fid_codes[cfid] / 10;

	freqs.new = powernow_table[index].frequency;

	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	/* Now do the magic poking into the MSRs.  */

	if (have_a0 == 1)	/* A0 errata 5 */
		local_irq_disable();

	if (freqs.old > freqs.new) {
		/* Going down, so change FID first */
		change_FID(fid);
		change_VID(vid);
	} else {
		/* Going up, so change VID first */
		change_VID(vid);
		change_FID(fid);
	}


	if (have_a0 == 1)
		local_irq_enable();

	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
}


#ifdef CONFIG_X86_POWERNOW_K7_ACPI

static struct acpi_processor_performance *acpi_processor_perf;

static int powernow_acpi_init(void)
{
	int i;
	int retval = 0;
	union powernow_acpi_control_t pc;

	if (acpi_processor_perf != NULL && powernow_table != NULL) {
		retval = -EINVAL;
		goto err0;
	}

	acpi_processor_perf = kzalloc(sizeof(struct acpi_processor_performance),
				      GFP_KERNEL);
	if (!acpi_processor_perf) {
		retval = -ENOMEM;
		goto err0;
	}

	if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
		retval = -EIO;
		goto err1;
	}

	if (acpi_processor_perf->control_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) {
		retval = -ENODEV;
		goto err2;
	}

	if (acpi_processor_perf->status_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) {
		retval = -ENODEV;
		goto err2;
	}

	number_scales = acpi_processor_perf->state_count;

	if (number_scales < 2) {
		retval = -ENODEV;
		goto err2;
	}

	powernow_table = kzalloc((number_scales + 1) * (sizeof(struct cpufreq_frequency_table)), GFP_KERNEL);
	if (!powernow_table) {
		retval = -ENOMEM;
		goto err2;
	}

	pc.val = (unsigned long) acpi_processor_perf->states[0].control;
	for (i = 0; i < number_scales; i++) {
		u8 fid, vid;
		struct acpi_processor_px *state =
			&acpi_processor_perf->states[i];
		unsigned int speed, speed_mhz;

		pc.val = (unsigned long) state->control;
		dprintk ("acpi:  P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
			 i,
			 (u32) state->core_frequency,