arch/i386/kernel/cpu/cpufreq/powernow-k7.c - arm/linux-arm-legacy - Git at Google

 /*
  *  AMD K7 Powernow driver.
  *  (C) 2003 Dave Jones <davej@codemonkey.org.uk> on behalf of SuSE Labs.
  *  (C) 2003-2004 Dave Jones <davej@redhat.com>
  *
  *  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 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 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;
 	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;
 		unsigned int speed;

 		pc.val = (unsigned long) acpi_processor_perf->states[i].control;
 		dprintk ("acpi:  P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
 			 i,
 			 (u32) acpi_processor_perf->states[i].core_frequency,
 			 (u32) acpi_processor_perf->states[i].power,
 			 (u32) acpi_processor_perf->states[i].transition_latency,
 			 (u32) acpi_processor_perf->states[i].control,
 			 pc.bits.sgtc);

 		vid = pc.bits.vid;
 		fid = pc.bits.fid;

 		powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
 		powernow_table[i].index = fid; /* lower 8 bits */
 		powernow_table[i].index |= (vid << 8); /* upper 8 bits */

 		speed = powernow_table[i].frequency;

 		if ((fid_codes[fid] % 10)==5) {
 			if (have_a0 == 1)
 				powernow_table[i].frequency = CPUFREQ_ENTRY_INVALID;
 		}

 		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);

 		if (latency < pc.bits.sgtc)
 			latency = pc.bits.sgtc;

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

 	powernow_table[i].frequency = CPUFREQ_TABLE_END;
 	powernow_table[i].index = 0;

 	/* notify BIOS that we exist */
 	acpi_processor_notify_smm(THIS_MODULE);

 	return 0;

 err2:
 	acpi_processor_unregister_performance(acpi_processor_perf, 0);
 err1:
 	kfree(acpi_processor_perf);
 err0:
 	printk(KERN_WARNING PFX "ACPI perflib can not be used in this platform\n");
 	acpi_processor_perf = NULL;
 	return retval;
 }
 #else
 static int powernow_acpi_init(void)
 {
 	printk(KERN_INFO PFX "no support for ACPI processor found."
 	       "  Please recompile your kernel with ACPI processor\n");
 	return -EINVAL;
 }
 #endif

 static int powernow_decode_bios (int maxfid, int startvid)
 {
 	struct psb_s *psb;
 	struct pst_s *pst;
 	unsigned int i, j;
 	unsigned char *p;
 	unsigned int etuple;
 	unsigned int ret;

 	etuple = cpuid_eax(0x80000001);

 	for (i=0xC0000; i < 0xffff0 ; i+=16) {

 		p = phys_to_virt(i);

 		if (memcmp(p, "AMDK7PNOW!",  10) == 0){
 			dprintk ("Found PSB header at %p\n", p);
 			psb = (struct psb_s *) p;
 			dprintk ("Table version: 0x%x\n", psb->tableversion);
 			if (psb->tableversion != 0x12) {
 				printk (KERN_INFO PFX "Sorry, only v1.2 tables supported right now\n");
 				return -ENODEV;
 			}

 			dprintk ("Flags: 0x%x\n", psb->flags);
 			if ((psb->flags & 1)==0) {
 				dprintk ("Mobile voltage regulator\n");
 			} else {
 				dprintk ("Desktop voltage regulator\n");
 			}

 			latency = psb->settlingtime;
 			if (latency < 100) {
 				printk (KERN_INFO PFX "BIOS set settling time to %d microseconds."
 						"Should be at least 100. Correcting.\n", latency);
 				latency = 100;
 			}
 			dprintk ("Settling Time: %d microseconds.\n", psb->settlingtime);
 			dprintk ("Has %d PST tables. (Only dumping ones relevant to this CPU).\n", psb->numpst);

 			p += sizeof (struct psb_s);

 			pst = (struct pst_s *) p;

 			for (j=0; j<psb->numpst; j++) {
 				pst = (struct pst_s *) p;
 				number_scales = pst->numpstates;

 				if ((etuple == pst->cpuid) && check_fsb(pst->fsbspeed) &&
 				    (maxfid==pst->maxfid) && (startvid==pst->startvid))
 				{
 					dprintk ("PST:%d (@%p)\n", j, pst);
 					dprintk (" cpuid: 0x%x  fsb: %d  maxFID: 0x%x  startvid: 0x%x\n",
 						 pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);

 					ret = get_ranges ((char *) pst + sizeof (struct pst_s));
 					return ret;
 				} else {
 					unsigned int k;
 					p = (char *) pst + sizeof (struct pst_s);
 					for (k=0; k<number_scales; k++)
 						p+=2;
 				}
 			}
 			printk (KERN_INFO PFX "No PST tables match this cpuid (0x%x)\n", etuple);
 			printk (KERN_INFO PFX "This is indicative of a broken BIOS.\n");

 			return -EINVAL;
 		}
 		p++;
 	}

 	return -ENODEV;
 }


 static int powernow_target (struct cpufreq_policy *policy,
 			    unsigned int target_freq,
 			    unsigned int relation)
 {
 	unsigned int newstate;

 	if (cpufreq_frequency_table_target(policy, powernow_table, target_freq, relation, &newstate))
 		return -EINVAL;

 	change_speed(newstate);

 	return 0;
 }


 static int powernow_verify (struct cpufreq_policy *policy)
 {
 	return cpufreq_frequency_table_verify(policy, powernow_table);
 }

 /*
  * We use the fact that the bus frequency is somehow
  * a multiple of 100000/3 khz, then we compute sgtc according
  * to this multiple.
  * That way, we match more how AMD thinks all of that work.
  * We will then get the same kind of behaviour already tested under
  * the "well-known" other OS.
  */
 static int __init fixup_sgtc(void)
 {
 	unsigned int sgtc;
 	unsigned int m;

 	m = fsb / 3333;
 	if ((m % 10) >= 5)
 		m += 5;

 	m /= 10;

 	sgtc = 100 * m * latency;
 	sgtc = sgtc / 3;
 	if (sgtc > 0xfffff) {
 		printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
 		sgtc = 0xfffff;
 	}
 	return sgtc;
 }

 static unsigned int powernow_get(unsigned int cpu)
 {
 	union msr_fidvidstatus fidvidstatus;
 	unsigned int cfid;

 	if (cpu)
 		return 0;
 	rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val);
 	cfid = fidvidstatus.bits.CFID;

 	return (fsb * fid_codes[cfid] / 10);
 }


 static int __init acer_cpufreq_pst(struct dmi_system_id *d)
 {
 	printk(KERN_WARNING "%s laptop with broken PST tables in BIOS detected.\n", d->ident);
 	printk(KERN_WARNING "You need to downgrade to 3A21 (09/09/2002), or try a newer BIOS than 3A71 (01/20/2003)\n");
 	printk(KERN_WARNING "cpufreq scaling has been disabled as a result of this.\n");
 	return 0;
 }

 /*
  * Some Athlon laptops have really fucked PST tables.
  * A BIOS update is all that can save them.
  * Mention this, and disable cpufreq.
  */
 static struct dmi_system_id __initdata powernow_dmi_table[] = {
 	{
 		.callback = acer_cpufreq_pst,
 		.ident = "Acer Aspire",
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
 			DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
 		},
 	},
 	{ }
 };

 static int __init powernow_cpu_init (struct cpufreq_policy *policy)
 {
 	union msr_fidvidstatus fidvidstatus;
 	int result;

 	if (policy->cpu != 0)
 		return -ENODEV;

 	rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val);

 	recalibrate_cpu_khz();

 	fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
 	if (!fsb) {
 		printk(KERN_WARNING PFX "can not determine bus frequency\n");
 		return -EINVAL;
 	}
 	dprintk("FSB: %3dMHz\n", fsb/1000);

 	if (dmi_check_system(powernow_dmi_table) || acpi_force) {
 		printk (KERN_INFO PFX "PSB/PST known to be broken.  Trying ACPI instead\n");
 		result = powernow_acpi_init();
 	} else {
 		result = powernow_decode_bios(fidvidstatus.bits.MFID, fidvidstatus.bits.SVID);
 		if (result) {
 			printk (KERN_INFO PFX "Trying ACPI perflib\n");
 			maximum_speed = 0;
 			minimum_speed = -1;
 			latency = 0;
 			result = powernow_acpi_init();
 			if (result) {
 				printk (KERN_INFO PFX "ACPI and legacy methods failed\n");
 				printk (KERN_INFO PFX "See http://www.codemonkey.org.uk/projects/cpufreq/powernow-k7.shtml\n");
 			}
 		} else {
 			/* SGTC use the bus clock as timer */
 			latency = fixup_sgtc();
 			printk(KERN_INFO PFX "SGTC: %d\n", latency);
 		}
 	}

 	if (result)
 		return result;

 	printk (KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
 				minimum_speed/1000, maximum_speed/1000);

 	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

 	policy->cpuinfo.transition_latency = cpufreq_scale(2000000UL, fsb, latency);

 	policy->cur = powernow_get(0);

 	cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);

 	return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
 }

 static int powernow_cpu_exit (struct cpufreq_policy *policy) {
 	cpufreq_frequency_table_put_attr(policy->cpu);

 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
 	if (acpi_processor_perf) {
 		acpi_processor_unregister_performance(acpi_processor_perf, 0);
 		kfree(acpi_processor_perf);
 	}
 #endif

 	kfree(powernow_table);
 	return 0;
 }

 static struct freq_attr* powernow_table_attr[] = {
 	&cpufreq_freq_attr_scaling_available_freqs,
 	NULL,
 };

 static struct cpufreq_driver powernow_driver = {
 	.verify	= powernow_verify,
 	.target	= powernow_target,
 	.get	= powernow_get,
 	.init	= powernow_cpu_init,
 	.exit	= powernow_cpu_exit,
 	.name	= "powernow-k7",
 	.owner	= THIS_MODULE,
 	.attr	= powernow_table_attr,
 };

 static int __init powernow_init (void)
 {
 	if (check_powernow()==0)
 		return -ENODEV;
 	return cpufreq_register_driver(&powernow_driver);
 }


 static void __exit powernow_exit (void)
 {
 	cpufreq_unregister_driver(&powernow_driver);
 }

 module_param(acpi_force,  int, 0444);
 MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");

 MODULE_AUTHOR ("Dave Jones <davej@codemonkey.org.uk>");
 MODULE_DESCRIPTION ("Powernow driver for AMD K7 processors.");
 MODULE_LICENSE ("GPL");

 late_initcall(powernow_init);
 module_exit(powernow_exit);
	/*
	* AMD K7 Powernow driver.
	* (C) 2003 Dave Jones <davej@codemonkey.org.uk> on behalf of SuSE Labs.
	* (C) 2003-2004 Dave Jones <davej@redhat.com>
	*
	* 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 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 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;
	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;
	unsigned int speed;

	pc.val = (unsigned long) acpi_processor_perf->states[i].control;
	dprintk ("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
	i,
	(u32) acpi_processor_perf->states[i].core_frequency,
	(u32) acpi_processor_perf->states[i].power,
	(u32) acpi_processor_perf->states[i].transition_latency,
	(u32) acpi_processor_perf->states[i].control,
	pc.bits.sgtc);

	vid = pc.bits.vid;
	fid = pc.bits.fid;

	powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
	powernow_table[i].index = fid; /* lower 8 bits */
	powernow_table[i].index \|= (vid << 8); /* upper 8 bits */

	speed = powernow_table[i].frequency;

	if ((fid_codes[fid] % 10)==5) {
	if (have_a0 == 1)
	powernow_table[i].frequency = CPUFREQ_ENTRY_INVALID;
	}

	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);

	if (latency < pc.bits.sgtc)
	latency = pc.bits.sgtc;

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

	powernow_table[i].frequency = CPUFREQ_TABLE_END;
	powernow_table[i].index = 0;

	/* notify BIOS that we exist */
	acpi_processor_notify_smm(THIS_MODULE);

	return 0;

	err2:
	acpi_processor_unregister_performance(acpi_processor_perf, 0);
	err1:
	kfree(acpi_processor_perf);
	err0:
	printk(KERN_WARNING PFX "ACPI perflib can not be used in this platform\n");
	acpi_processor_perf = NULL;
	return retval;
	}
	#else
	static int powernow_acpi_init(void)
	{
	printk(KERN_INFO PFX "no support for ACPI processor found."
	" Please recompile your kernel with ACPI processor\n");
	return -EINVAL;
	}
	#endif

	static int powernow_decode_bios (int maxfid, int startvid)
	{
	struct psb_s *psb;
	struct pst_s *pst;
	unsigned int i, j;
	unsigned char *p;
	unsigned int etuple;
	unsigned int ret;

	etuple = cpuid_eax(0x80000001);

	for (i=0xC0000; i < 0xffff0 ; i+=16) {

	p = phys_to_virt(i);

	if (memcmp(p, "AMDK7PNOW!", 10) == 0){
	dprintk ("Found PSB header at %p\n", p);
	psb = (struct psb_s *) p;
	dprintk ("Table version: 0x%x\n", psb->tableversion);
	if (psb->tableversion != 0x12) {
	printk (KERN_INFO PFX "Sorry, only v1.2 tables supported right now\n");
	return -ENODEV;
	}

	dprintk ("Flags: 0x%x\n", psb->flags);
	if ((psb->flags & 1)==0) {
	dprintk ("Mobile voltage regulator\n");
	} else {
	dprintk ("Desktop voltage regulator\n");
	}

	latency = psb->settlingtime;
	if (latency < 100) {
	printk (KERN_INFO PFX "BIOS set settling time to %d microseconds."
	"Should be at least 100. Correcting.\n", latency);
	latency = 100;
	}
	dprintk ("Settling Time: %d microseconds.\n", psb->settlingtime);
	dprintk ("Has %d PST tables. (Only dumping ones relevant to this CPU).\n", psb->numpst);

	p += sizeof (struct psb_s);

	pst = (struct pst_s *) p;

	for (j=0; j<psb->numpst; j++) {
	pst = (struct pst_s *) p;
	number_scales = pst->numpstates;

	if ((etuple == pst->cpuid) && check_fsb(pst->fsbspeed) &&
	(maxfid==pst->maxfid) && (startvid==pst->startvid))
	{
	dprintk ("PST:%d (@%p)\n", j, pst);
	dprintk (" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n",
	pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);

	ret = get_ranges ((char *) pst + sizeof (struct pst_s));
	return ret;
	} else {
	unsigned int k;
	p = (char *) pst + sizeof (struct pst_s);
	for (k=0; k<number_scales; k++)
	p+=2;
	}
	}
	printk (KERN_INFO PFX "No PST tables match this cpuid (0x%x)\n", etuple);
	printk (KERN_INFO PFX "This is indicative of a broken BIOS.\n");

	return -EINVAL;
	}
	p++;
	}

	return -ENODEV;
	}


	static int powernow_target (struct cpufreq_policy *policy,
	unsigned int target_freq,
	unsigned int relation)
	{
	unsigned int newstate;

	if (cpufreq_frequency_table_target(policy, powernow_table, target_freq, relation, &newstate))
	return -EINVAL;

	change_speed(newstate);

	return 0;
	}


	static int powernow_verify (struct cpufreq_policy *policy)
	{
	return cpufreq_frequency_table_verify(policy, powernow_table);
	}

	/*
	* We use the fact that the bus frequency is somehow
	* a multiple of 100000/3 khz, then we compute sgtc according
	* to this multiple.
	* That way, we match more how AMD thinks all of that work.
	* We will then get the same kind of behaviour already tested under
	* the "well-known" other OS.
	*/
	static int __init fixup_sgtc(void)
	{
	unsigned int sgtc;
	unsigned int m;

	m = fsb / 3333;
	if ((m % 10) >= 5)
	m += 5;

	m /= 10;

	sgtc = 100 * m * latency;
	sgtc = sgtc / 3;
	if (sgtc > 0xfffff) {
	printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
	sgtc = 0xfffff;
	}
	return sgtc;
	}

	static unsigned int powernow_get(unsigned int cpu)
	{
	union msr_fidvidstatus fidvidstatus;
	unsigned int cfid;

	if (cpu)
	return 0;
	rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val);
	cfid = fidvidstatus.bits.CFID;

	return (fsb * fid_codes[cfid] / 10);
	}


	static int __init acer_cpufreq_pst(struct dmi_system_id *d)
	{
	printk(KERN_WARNING "%s laptop with broken PST tables in BIOS detected.\n", d->ident);
	printk(KERN_WARNING "You need to downgrade to 3A21 (09/09/2002), or try a newer BIOS than 3A71 (01/20/2003)\n");
	printk(KERN_WARNING "cpufreq scaling has been disabled as a result of this.\n");
	return 0;
	}

	/*
	* Some Athlon laptops have really fucked PST tables.
	* A BIOS update is all that can save them.
	* Mention this, and disable cpufreq.
	*/
	static struct dmi_system_id __initdata powernow_dmi_table[] = {
	{
	.callback = acer_cpufreq_pst,
	.ident = "Acer Aspire",
	.matches = {
	DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
	DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
	},
	},
	{ }
	};

	static int __init powernow_cpu_init (struct cpufreq_policy *policy)
	{
	union msr_fidvidstatus fidvidstatus;
	int result;

	if (policy->cpu != 0)
	return -ENODEV;

	rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val);

	recalibrate_cpu_khz();

	fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
	if (!fsb) {
	printk(KERN_WARNING PFX "can not determine bus frequency\n");
	return -EINVAL;
	}
	dprintk("FSB: %3dMHz\n", fsb/1000);

	if (dmi_check_system(powernow_dmi_table) \|\| acpi_force) {
	printk (KERN_INFO PFX "PSB/PST known to be broken. Trying ACPI instead\n");
	result = powernow_acpi_init();
	} else {
	result = powernow_decode_bios(fidvidstatus.bits.MFID, fidvidstatus.bits.SVID);
	if (result) {
	printk (KERN_INFO PFX "Trying ACPI perflib\n");
	maximum_speed = 0;
	minimum_speed = -1;
	latency = 0;
	result = powernow_acpi_init();
	if (result) {
	printk (KERN_INFO PFX "ACPI and legacy methods failed\n");
	printk (KERN_INFO PFX "See http://www.codemonkey.org.uk/projects/cpufreq/powernow-k7.shtml\n");
	}
	} else {
	/* SGTC use the bus clock as timer */
	latency = fixup_sgtc();
	printk(KERN_INFO PFX "SGTC: %d\n", latency);
	}
	}

	if (result)
	return result;

	printk (KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
	minimum_speed/1000, maximum_speed/1000);

	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

	policy->cpuinfo.transition_latency = cpufreq_scale(2000000UL, fsb, latency);

	policy->cur = powernow_get(0);

	cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);

	return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
	}

	static int powernow_cpu_exit (struct cpufreq_policy *policy) {
	cpufreq_frequency_table_put_attr(policy->cpu);

	#ifdef CONFIG_X86_POWERNOW_K7_ACPI
	if (acpi_processor_perf) {
	acpi_processor_unregister_performance(acpi_processor_perf, 0);
	kfree(acpi_processor_perf);
	}
	#endif

	kfree(powernow_table);
	return 0;
	}

	static struct freq_attr* powernow_table_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	NULL,
	};

	static struct cpufreq_driver powernow_driver = {
	.verify = powernow_verify,
	.target = powernow_target,
	.get = powernow_get,
	.init = powernow_cpu_init,
	.exit = powernow_cpu_exit,
	.name = "powernow-k7",
	.owner = THIS_MODULE,
	.attr = powernow_table_attr,
	};

	static int __init powernow_init (void)
	{
	if (check_powernow()==0)
	return -ENODEV;
	return cpufreq_register_driver(&powernow_driver);
	}


	static void __exit powernow_exit (void)
	{
	cpufreq_unregister_driver(&powernow_driver);
	}

	module_param(acpi_force, int, 0444);
	MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");

	MODULE_AUTHOR ("Dave Jones <davej@codemonkey.org.uk>");
	MODULE_DESCRIPTION ("Powernow driver for AMD K7 processors.");
	MODULE_LICENSE ("GPL");

	late_initcall(powernow_init);
	module_exit(powernow_exit);