WebSVN - shark - Rev 769 - /shark/trunk/drivers/cpu/cpufreq/powernow-k7.c

/*
* AMD K7 Powernow driver.
* (C) 2003 Dave Jones <davej@codemonkey.org.uk> on behalf of SuSE Labs.
* (C) 2003 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.
*
* BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
*
* 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 <linuxcomp.h>

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

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

#include "powernow-k7.h"

//#define DEBUG

#ifdef DEBUG
#define dprintk(msg...) printk(msg)
#else
#define dprintk(msg...) do { } while(0)
#endif

#define PFX "powernow: "

extern struct cpuinfo_x86 new_cpu_data;

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;
};

/* divide by 1000 to get VID. */
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, 1024, 1000, 975, 950, 925, 0,
};

/* 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,
};

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;

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

if (c->x86_vendor != X86_VENDOR_AMD) {
dprintk (KERN_INFO PFX "AMD processor not detected.\n");
return 0;
}

if (c->x86 !=6) {
dprintk (KERN_INFO PFX "This module only works with AMD K7 CPUs\n");
return 0;
}

printk (KERN_INFO PFX "AMD K7 CPU detected.\n");

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

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

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

if (!(edx & (1 << 1 | 1 << 2))) {
printk ("nothing.\n");
return 0;
}

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

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

powernow_table = kmalloc((sizeof(struct cpufreq_frequency_table) * (number_scales + 1)), GFP_KERNEL);
if (!powernow_table)
return -ENOMEM;
memset(powernow_table, 0, (sizeof(struct cpufreq_frequency_table) * (number_scales + 1)));

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

powernow_table[j].frequency = fsb * fid_codes[fid] * 100;
powernow_table[j].index = fid; /* lower 8 bits */

speed = fsb * (fid_codes[fid]/10);
if ((fid_codes[fid] % 10)==5) {
speed += fsb/2;
#if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
if (have_a0 == 1)
powernow_table[j].frequency = CPUFREQ_ENTRY_INVALID;
#endif
}

dprintk (KERN_INFO PFX " FID: 0x%x (%d.%dx [%dMHz])\t", fid,
fid_codes[fid] / 10, fid_codes[fid] % 10, speed);

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 ("VID: 0x%x (%d.%03dV)\n", vid, mobile_vid_table[vid]/1000,
mobile_vid_table[vid]%1000);
}
dprintk ("\n");

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] * 100;
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);
}

static int powernow_decode_bios (int maxfid, int startvid)
{
struct psb_s *psb;
struct pst_s *pst;
struct cpuinfo_x86 *c = &new_cpu_data; /* Nino */
unsigned int i, j;
unsigned char *p;
unsigned int etuple;
unsigned int ret;

etuple = cpuid_eax(0x80000001);
etuple &= 0xf00;
etuple |= (c->x86_model<<4)|(c->x86_mask);

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

p = phys_to_virt(i);

if (memcmp(p, "AMDK7PNOW!", 10) == 0){
dprintk (KERN_INFO PFX "Found PSB header at %p\n", p);
psb = (struct psb_s *) p;
dprintk (KERN_INFO PFX "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 (KERN_INFO PFX "Flags: 0x%x (", psb->flags);
if ((psb->flags & 1)==0) {
dprintk ("Mobile");
} else {
dprintk ("Desktop");
}
dprintk (" 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 (KERN_INFO PFX "Settling Time: %d microseconds.\n", psb->settlingtime);
dprintk (KERN_INFO PFX "Has %d PST tables. (Only dumping ones relevant to this CPU).\n", psb->numpst);
latency *= 100; /* SGTC needs to be in units of 10ns */

p += sizeof (struct psb_s);

pst = (struct pst_s *) p;

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

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

fsb = pst->fsbspeed;
ret = get_ranges ((char *) pst + sizeof (struct pst_s));
return ret;

} else {
p = (char *) pst + sizeof (struct pst_s);
for (j=0 ; j < number_scales; j++)
p+=2;
}
}
printk (KERN_INFO PFX "No PST tables match this cpuid (0x%x)\n", etuple);
printk ("This is indicative of a broken BIOS. Email davej@redhat.com\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);
}

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);

result = powernow_decode_bios(fidvidstatus.bits.MFID, fidvidstatus.bits.SVID);
if (result)
return result;

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

policy->governor = 0; //!!!CPUFREQ_DEFAULT_GOVERNOR;
policy->cpuinfo.transition_latency = latency;
policy->cur = maximum_speed;

return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
}

static struct cpufreq_driver powernow_driver = {
.verify = powernow_verify,
.target = powernow_target,
.init = powernow_cpu_init,
.name = "powernow-k7",
.owner = THIS_MODULE,
};

/*static*/ int __init powernow_init (void)
{
/*!!!if (dmi_broken & BROKEN_CPUFREQ) {
printk (KERN_INFO PFX "Disabled at boot time by DMI,\n");
return -ENODEV;
}*/
if (check_powernow()==0)
return -ENODEV;
return cpufreq_register_driver(&powernow_driver);
}

/*static*/ void __exit powernow_exit (void)
{
cpufreq_unregister_driver(&powernow_driver);
if (powernow_table)
kfree(powernow_table);
}

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

module_init(powernow_init);
module_exit(powernow_exit);

Subversion Repositories shark

(root)/shark/trunk/drivers/cpu/cpufreq/powernow-k7.c - Rev 769