linux/drivers/cpufreq/longhaul.c
Rafał Bilski b5811bc469 cpufreq / Longhaul: Disable driver by default
This is only solution I can think of. User decides if he wants this
driver on his machine. I don't have enough knowledge and time to find
the reason why same code works on some machines and doesn't on others
which use the same, or very similar, chipset and processor.

Signed-off-by: Rafał Bilski <rafalbilski@interia.pl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-01-03 13:11:18 +01:00

1039 lines
26 KiB
C

/*
* (C) 2001-2004 Dave Jones. <davej@redhat.com>
* (C) 2002 Padraig Brady. <padraig@antefacto.com>
*
* Licensed under the terms of the GNU GPL License version 2.
* Based upon datasheets & sample CPUs kindly provided by VIA.
*
* VIA have currently 3 different versions of Longhaul.
* Version 1 (Longhaul) uses the BCR2 MSR at 0x1147.
* It is present only in Samuel 1 (C5A), Samuel 2 (C5B) stepping 0.
* Version 2 of longhaul is backward compatible with v1, but adds
* LONGHAUL MSR for purpose of both frequency and voltage scaling.
* Present in Samuel 2 (steppings 1-7 only) (C5B), and Ezra (C5C).
* Version 3 of longhaul got renamed to Powersaver and redesigned
* to use only the POWERSAVER MSR at 0x110a.
* It is present in Ezra-T (C5M), Nehemiah (C5X) and above.
* It's pretty much the same feature wise to longhaul v2, though
* there is provision for scaling FSB too, but this doesn't work
* too well in practice so we don't even try to use this.
*
* BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/timex.h>
#include <linux/io.h>
#include <linux/acpi.h>
#include <asm/msr.h>
#include <asm/cpu_device_id.h>
#include <acpi/processor.h>
#include "longhaul.h"
#define PFX "longhaul: "
#define TYPE_LONGHAUL_V1 1
#define TYPE_LONGHAUL_V2 2
#define TYPE_POWERSAVER 3
#define CPU_SAMUEL 1
#define CPU_SAMUEL2 2
#define CPU_EZRA 3
#define CPU_EZRA_T 4
#define CPU_NEHEMIAH 5
#define CPU_NEHEMIAH_C 6
/* Flags */
#define USE_ACPI_C3 (1 << 1)
#define USE_NORTHBRIDGE (1 << 2)
static int cpu_model;
static unsigned int numscales = 16;
static unsigned int fsb;
static const struct mV_pos *vrm_mV_table;
static const unsigned char *mV_vrm_table;
static unsigned int highest_speed, lowest_speed; /* kHz */
static unsigned int minmult, maxmult;
static int can_scale_voltage;
static struct acpi_processor *pr;
static struct acpi_processor_cx *cx;
static u32 acpi_regs_addr;
static u8 longhaul_flags;
static unsigned int longhaul_index;
/* Module parameters */
static int scale_voltage;
static int disable_acpi_c3;
static int revid_errata;
static int enable;
/* Clock ratios multiplied by 10 */
static int mults[32];
static int eblcr[32];
static int longhaul_version;
static struct cpufreq_frequency_table *longhaul_table;
static char speedbuffer[8];
static char *print_speed(int speed)
{
if (speed < 1000) {
snprintf(speedbuffer, sizeof(speedbuffer), "%dMHz", speed);
return speedbuffer;
}
if (speed%1000 == 0)
snprintf(speedbuffer, sizeof(speedbuffer),
"%dGHz", speed/1000);
else
snprintf(speedbuffer, sizeof(speedbuffer),
"%d.%dGHz", speed/1000, (speed%1000)/100);
return speedbuffer;
}
static unsigned int calc_speed(int mult)
{
int khz;
khz = (mult/10)*fsb;
if (mult%10)
khz += fsb/2;
khz *= 1000;
return khz;
}
static int longhaul_get_cpu_mult(void)
{
unsigned long invalue = 0, lo, hi;
rdmsr(MSR_IA32_EBL_CR_POWERON, lo, hi);
invalue = (lo & (1<<22|1<<23|1<<24|1<<25))>>22;
if (longhaul_version == TYPE_LONGHAUL_V2 ||
longhaul_version == TYPE_POWERSAVER) {
if (lo & (1<<27))
invalue += 16;
}
return eblcr[invalue];
}
/* For processor with BCR2 MSR */
static void do_longhaul1(unsigned int mults_index)
{
union msr_bcr2 bcr2;
rdmsrl(MSR_VIA_BCR2, bcr2.val);
/* Enable software clock multiplier */
bcr2.bits.ESOFTBF = 1;
bcr2.bits.CLOCKMUL = mults_index & 0xff;
/* Sync to timer tick */
safe_halt();
/* Change frequency on next halt or sleep */
wrmsrl(MSR_VIA_BCR2, bcr2.val);
/* Invoke transition */
ACPI_FLUSH_CPU_CACHE();
halt();
/* Disable software clock multiplier */
local_irq_disable();
rdmsrl(MSR_VIA_BCR2, bcr2.val);
bcr2.bits.ESOFTBF = 0;
wrmsrl(MSR_VIA_BCR2, bcr2.val);
}
/* For processor with Longhaul MSR */
static void do_powersaver(int cx_address, unsigned int mults_index,
unsigned int dir)
{
union msr_longhaul longhaul;
u32 t;
rdmsrl(MSR_VIA_LONGHAUL, longhaul.val);
/* Setup new frequency */
if (!revid_errata)
longhaul.bits.RevisionKey = longhaul.bits.RevisionID;
else
longhaul.bits.RevisionKey = 0;
longhaul.bits.SoftBusRatio = mults_index & 0xf;
longhaul.bits.SoftBusRatio4 = (mults_index & 0x10) >> 4;
/* Setup new voltage */
if (can_scale_voltage)
longhaul.bits.SoftVID = (mults_index >> 8) & 0x1f;
/* Sync to timer tick */
safe_halt();
/* Raise voltage if necessary */
if (can_scale_voltage && dir) {
longhaul.bits.EnableSoftVID = 1;
wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
/* Change voltage */
if (!cx_address) {
ACPI_FLUSH_CPU_CACHE();
halt();
} else {
ACPI_FLUSH_CPU_CACHE();
/* Invoke C3 */
inb(cx_address);
/* Dummy op - must do something useless after P_LVL3
* read */
t = inl(acpi_gbl_FADT.xpm_timer_block.address);
}
longhaul.bits.EnableSoftVID = 0;
wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
}
/* Change frequency on next halt or sleep */
longhaul.bits.EnableSoftBusRatio = 1;
wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
if (!cx_address) {
ACPI_FLUSH_CPU_CACHE();
halt();
} else {
ACPI_FLUSH_CPU_CACHE();
/* Invoke C3 */
inb(cx_address);
/* Dummy op - must do something useless after P_LVL3 read */
t = inl(acpi_gbl_FADT.xpm_timer_block.address);
}
/* Disable bus ratio bit */
longhaul.bits.EnableSoftBusRatio = 0;
wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
/* Reduce voltage if necessary */
if (can_scale_voltage && !dir) {
longhaul.bits.EnableSoftVID = 1;
wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
/* Change voltage */
if (!cx_address) {
ACPI_FLUSH_CPU_CACHE();
halt();
} else {
ACPI_FLUSH_CPU_CACHE();
/* Invoke C3 */
inb(cx_address);
/* Dummy op - must do something useless after P_LVL3
* read */
t = inl(acpi_gbl_FADT.xpm_timer_block.address);
}
longhaul.bits.EnableSoftVID = 0;
wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
}
}
/**
* longhaul_set_cpu_frequency()
* @mults_index : bitpattern of the new multiplier.
*
* Sets a new clock ratio.
*/
static void longhaul_setstate(unsigned int table_index)
{
unsigned int mults_index;
int speed, mult;
struct cpufreq_freqs freqs;
unsigned long flags;
unsigned int pic1_mask, pic2_mask;
u16 bm_status = 0;
u32 bm_timeout = 1000;
unsigned int dir = 0;
mults_index = longhaul_table[table_index].index;
/* Safety precautions */
mult = mults[mults_index & 0x1f];
if (mult == -1)
return;
speed = calc_speed(mult);
if ((speed > highest_speed) || (speed < lowest_speed))
return;
/* Voltage transition before frequency transition? */
if (can_scale_voltage && longhaul_index < table_index)
dir = 1;
freqs.old = calc_speed(longhaul_get_cpu_mult());
freqs.new = speed;
freqs.cpu = 0; /* longhaul.c is UP only driver */
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
pr_debug("Setting to FSB:%dMHz Mult:%d.%dx (%s)\n",
fsb, mult/10, mult%10, print_speed(speed/1000));
retry_loop:
preempt_disable();
local_irq_save(flags);
pic2_mask = inb(0xA1);
pic1_mask = inb(0x21); /* works on C3. save mask. */
outb(0xFF, 0xA1); /* Overkill */
outb(0xFE, 0x21); /* TMR0 only */
/* Wait while PCI bus is busy. */
if (acpi_regs_addr && (longhaul_flags & USE_NORTHBRIDGE
|| ((pr != NULL) && pr->flags.bm_control))) {
bm_status = inw(acpi_regs_addr);
bm_status &= 1 << 4;
while (bm_status && bm_timeout) {
outw(1 << 4, acpi_regs_addr);
bm_timeout--;
bm_status = inw(acpi_regs_addr);
bm_status &= 1 << 4;
}
}
if (longhaul_flags & USE_NORTHBRIDGE) {
/* Disable AGP and PCI arbiters */
outb(3, 0x22);
} else if ((pr != NULL) && pr->flags.bm_control) {
/* Disable bus master arbitration */
acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
}
switch (longhaul_version) {
/*
* Longhaul v1. (Samuel[C5A] and Samuel2 stepping 0[C5B])
* Software controlled multipliers only.
*/
case TYPE_LONGHAUL_V1:
do_longhaul1(mults_index);
break;
/*
* Longhaul v2 appears in Samuel2 Steppings 1->7 [C5B] and Ezra [C5C]
*
* Longhaul v3 (aka Powersaver). (Ezra-T [C5M] & Nehemiah [C5N])
* Nehemiah can do FSB scaling too, but this has never been proven
* to work in practice.
*/
case TYPE_LONGHAUL_V2:
case TYPE_POWERSAVER:
if (longhaul_flags & USE_ACPI_C3) {
/* Don't allow wakeup */
acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
do_powersaver(cx->address, mults_index, dir);
} else {
do_powersaver(0, mults_index, dir);
}
break;
}
if (longhaul_flags & USE_NORTHBRIDGE) {
/* Enable arbiters */
outb(0, 0x22);
} else if ((pr != NULL) && pr->flags.bm_control) {
/* Enable bus master arbitration */
acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
}
outb(pic2_mask, 0xA1); /* restore mask */
outb(pic1_mask, 0x21);
local_irq_restore(flags);
preempt_enable();
freqs.new = calc_speed(longhaul_get_cpu_mult());
/* Check if requested frequency is set. */
if (unlikely(freqs.new != speed)) {
printk(KERN_INFO PFX "Failed to set requested frequency!\n");
/* Revision ID = 1 but processor is expecting revision key
* equal to 0. Jumpers at the bottom of processor will change
* multiplier and FSB, but will not change bits in Longhaul
* MSR nor enable voltage scaling. */
if (!revid_errata) {
printk(KERN_INFO PFX "Enabling \"Ignore Revision ID\" "
"option.\n");
revid_errata = 1;
msleep(200);
goto retry_loop;
}
/* Why ACPI C3 sometimes doesn't work is a mystery for me.
* But it does happen. Processor is entering ACPI C3 state,
* but it doesn't change frequency. I tried poking various
* bits in northbridge registers, but without success. */
if (longhaul_flags & USE_ACPI_C3) {
printk(KERN_INFO PFX "Disabling ACPI C3 support.\n");
longhaul_flags &= ~USE_ACPI_C3;
if (revid_errata) {
printk(KERN_INFO PFX "Disabling \"Ignore "
"Revision ID\" option.\n");
revid_errata = 0;
}
msleep(200);
goto retry_loop;
}
/* This shouldn't happen. Longhaul ver. 2 was reported not
* working on processors without voltage scaling, but with
* RevID = 1. RevID errata will make things right. Just
* to be 100% sure. */
if (longhaul_version == TYPE_LONGHAUL_V2) {
printk(KERN_INFO PFX "Switching to Longhaul ver. 1\n");
longhaul_version = TYPE_LONGHAUL_V1;
msleep(200);
goto retry_loop;
}
}
/* Report true CPU frequency */
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
if (!bm_timeout)
printk(KERN_INFO PFX "Warning: Timeout while waiting for "
"idle PCI bus.\n");
}
/*
* Centaur decided to make life a little more tricky.
* Only longhaul v1 is allowed to read EBLCR BSEL[0:1].
* Samuel2 and above have to try and guess what the FSB is.
* We do this by assuming we booted at maximum multiplier, and interpolate
* between that value multiplied by possible FSBs and cpu_mhz which
* was calculated at boot time. Really ugly, but no other way to do this.
*/
#define ROUNDING 0xf
static int guess_fsb(int mult)
{
int speed = cpu_khz / 1000;
int i;
int speeds[] = { 666, 1000, 1333, 2000 };
int f_max, f_min;
for (i = 0; i < 4; i++) {
f_max = ((speeds[i] * mult) + 50) / 100;
f_max += (ROUNDING / 2);
f_min = f_max - ROUNDING;
if ((speed <= f_max) && (speed >= f_min))
return speeds[i] / 10;
}
return 0;
}
static int __cpuinit longhaul_get_ranges(void)
{
unsigned int i, j, k = 0;
unsigned int ratio;
int mult;
/* Get current frequency */
mult = longhaul_get_cpu_mult();
if (mult == -1) {
printk(KERN_INFO PFX "Invalid (reserved) multiplier!\n");
return -EINVAL;
}
fsb = guess_fsb(mult);
if (fsb == 0) {
printk(KERN_INFO PFX "Invalid (reserved) FSB!\n");
return -EINVAL;
}
/* Get max multiplier - as we always did.
* Longhaul MSR is useful only when voltage scaling is enabled.
* C3 is booting at max anyway. */
maxmult = mult;
/* Get min multiplier */
switch (cpu_model) {
case CPU_NEHEMIAH:
minmult = 50;
break;
case CPU_NEHEMIAH_C:
minmult = 40;
break;
default:
minmult = 30;
break;
}
pr_debug("MinMult:%d.%dx MaxMult:%d.%dx\n",
minmult/10, minmult%10, maxmult/10, maxmult%10);
highest_speed = calc_speed(maxmult);
lowest_speed = calc_speed(minmult);
pr_debug("FSB:%dMHz Lowest speed: %s Highest speed:%s\n", fsb,
print_speed(lowest_speed/1000),
print_speed(highest_speed/1000));
if (lowest_speed == highest_speed) {
printk(KERN_INFO PFX "highestspeed == lowest, aborting.\n");
return -EINVAL;
}
if (lowest_speed > highest_speed) {
printk(KERN_INFO PFX "nonsense! lowest (%d > %d) !\n",
lowest_speed, highest_speed);
return -EINVAL;
}
longhaul_table = kmalloc((numscales + 1) * sizeof(*longhaul_table),
GFP_KERNEL);
if (!longhaul_table)
return -ENOMEM;
for (j = 0; j < numscales; j++) {
ratio = mults[j];
if (ratio == -1)
continue;
if (ratio > maxmult || ratio < minmult)
continue;
longhaul_table[k].frequency = calc_speed(ratio);
longhaul_table[k].index = j;
k++;
}
if (k <= 1) {
kfree(longhaul_table);
return -ENODEV;
}
/* Sort */
for (j = 0; j < k - 1; j++) {
unsigned int min_f, min_i;
min_f = longhaul_table[j].frequency;
min_i = j;
for (i = j + 1; i < k; i++) {
if (longhaul_table[i].frequency < min_f) {
min_f = longhaul_table[i].frequency;
min_i = i;
}
}
if (min_i != j) {
swap(longhaul_table[j].frequency,
longhaul_table[min_i].frequency);
swap(longhaul_table[j].index,
longhaul_table[min_i].index);
}
}
longhaul_table[k].frequency = CPUFREQ_TABLE_END;
/* Find index we are running on */
for (j = 0; j < k; j++) {
if (mults[longhaul_table[j].index & 0x1f] == mult) {
longhaul_index = j;
break;
}
}
return 0;
}
static void __cpuinit longhaul_setup_voltagescaling(void)
{
union msr_longhaul longhaul;
struct mV_pos minvid, maxvid, vid;
unsigned int j, speed, pos, kHz_step, numvscales;
int min_vid_speed;
rdmsrl(MSR_VIA_LONGHAUL, longhaul.val);
if (!(longhaul.bits.RevisionID & 1)) {
printk(KERN_INFO PFX "Voltage scaling not supported by CPU.\n");
return;
}
if (!longhaul.bits.VRMRev) {
printk(KERN_INFO PFX "VRM 8.5\n");
vrm_mV_table = &vrm85_mV[0];
mV_vrm_table = &mV_vrm85[0];
} else {
printk(KERN_INFO PFX "Mobile VRM\n");
if (cpu_model < CPU_NEHEMIAH)
return;
vrm_mV_table = &mobilevrm_mV[0];
mV_vrm_table = &mV_mobilevrm[0];
}
minvid = vrm_mV_table[longhaul.bits.MinimumVID];
maxvid = vrm_mV_table[longhaul.bits.MaximumVID];
if (minvid.mV == 0 || maxvid.mV == 0 || minvid.mV > maxvid.mV) {
printk(KERN_INFO PFX "Bogus values Min:%d.%03d Max:%d.%03d. "
"Voltage scaling disabled.\n",
minvid.mV/1000, minvid.mV%1000,
maxvid.mV/1000, maxvid.mV%1000);
return;
}
if (minvid.mV == maxvid.mV) {
printk(KERN_INFO PFX "Claims to support voltage scaling but "
"min & max are both %d.%03d. "
"Voltage scaling disabled\n",
maxvid.mV/1000, maxvid.mV%1000);
return;
}
/* How many voltage steps*/
numvscales = maxvid.pos - minvid.pos + 1;
printk(KERN_INFO PFX
"Max VID=%d.%03d "
"Min VID=%d.%03d, "
"%d possible voltage scales\n",
maxvid.mV/1000, maxvid.mV%1000,
minvid.mV/1000, minvid.mV%1000,
numvscales);
/* Calculate max frequency at min voltage */
j = longhaul.bits.MinMHzBR;
if (longhaul.bits.MinMHzBR4)
j += 16;
min_vid_speed = eblcr[j];
if (min_vid_speed == -1)
return;
switch (longhaul.bits.MinMHzFSB) {
case 0:
min_vid_speed *= 13333;
break;
case 1:
min_vid_speed *= 10000;
break;
case 3:
min_vid_speed *= 6666;
break;
default:
return;
break;
}
if (min_vid_speed >= highest_speed)
return;
/* Calculate kHz for one voltage step */
kHz_step = (highest_speed - min_vid_speed) / numvscales;
j = 0;
while (longhaul_table[j].frequency != CPUFREQ_TABLE_END) {
speed = longhaul_table[j].frequency;
if (speed > min_vid_speed)
pos = (speed - min_vid_speed) / kHz_step + minvid.pos;
else
pos = minvid.pos;
longhaul_table[j].index |= mV_vrm_table[pos] << 8;
vid = vrm_mV_table[mV_vrm_table[pos]];
printk(KERN_INFO PFX "f: %d kHz, index: %d, vid: %d mV\n",
speed, j, vid.mV);
j++;
}
can_scale_voltage = 1;
printk(KERN_INFO PFX "Voltage scaling enabled.\n");
}
static int longhaul_verify(struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy, longhaul_table);
}
static int longhaul_target(struct cpufreq_policy *policy,
unsigned int target_freq, unsigned int relation)
{
unsigned int table_index = 0;
unsigned int i;
unsigned int dir = 0;
u8 vid, current_vid;
if (cpufreq_frequency_table_target(policy, longhaul_table, target_freq,
relation, &table_index))
return -EINVAL;
/* Don't set same frequency again */
if (longhaul_index == table_index)
return 0;
if (!can_scale_voltage)
longhaul_setstate(table_index);
else {
/* On test system voltage transitions exceeding single
* step up or down were turning motherboard off. Both
* "ondemand" and "userspace" are unsafe. C7 is doing
* this in hardware, C3 is old and we need to do this
* in software. */
i = longhaul_index;
current_vid = (longhaul_table[longhaul_index].index >> 8);
current_vid &= 0x1f;
if (table_index > longhaul_index)
dir = 1;
while (i != table_index) {
vid = (longhaul_table[i].index >> 8) & 0x1f;
if (vid != current_vid) {
longhaul_setstate(i);
current_vid = vid;
msleep(200);
}
if (dir)
i++;
else
i--;
}
longhaul_setstate(table_index);
}
longhaul_index = table_index;
return 0;
}
static unsigned int longhaul_get(unsigned int cpu)
{
if (cpu)
return 0;
return calc_speed(longhaul_get_cpu_mult());
}
static acpi_status longhaul_walk_callback(acpi_handle obj_handle,
u32 nesting_level,
void *context, void **return_value)
{
struct acpi_device *d;
if (acpi_bus_get_device(obj_handle, &d))
return 0;
*return_value = acpi_driver_data(d);
return 1;
}
/* VIA don't support PM2 reg, but have something similar */
static int enable_arbiter_disable(void)
{
struct pci_dev *dev;
int status = 1;
int reg;
u8 pci_cmd;
/* Find PLE133 host bridge */
reg = 0x78;
dev = pci_get_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8601_0,
NULL);
/* Find PM133/VT8605 host bridge */
if (dev == NULL)
dev = pci_get_device(PCI_VENDOR_ID_VIA,
PCI_DEVICE_ID_VIA_8605_0, NULL);
/* Find CLE266 host bridge */
if (dev == NULL) {
reg = 0x76;
dev = pci_get_device(PCI_VENDOR_ID_VIA,
PCI_DEVICE_ID_VIA_862X_0, NULL);
/* Find CN400 V-Link host bridge */
if (dev == NULL)
dev = pci_get_device(PCI_VENDOR_ID_VIA, 0x7259, NULL);
}
if (dev != NULL) {
/* Enable access to port 0x22 */
pci_read_config_byte(dev, reg, &pci_cmd);
if (!(pci_cmd & 1<<7)) {
pci_cmd |= 1<<7;
pci_write_config_byte(dev, reg, pci_cmd);
pci_read_config_byte(dev, reg, &pci_cmd);
if (!(pci_cmd & 1<<7)) {
printk(KERN_ERR PFX
"Can't enable access to port 0x22.\n");
status = 0;
}
}
pci_dev_put(dev);
return status;
}
return 0;
}
static int longhaul_setup_southbridge(void)
{
struct pci_dev *dev;
u8 pci_cmd;
/* Find VT8235 southbridge */
dev = pci_get_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235, NULL);
if (dev == NULL)
/* Find VT8237 southbridge */
dev = pci_get_device(PCI_VENDOR_ID_VIA,
PCI_DEVICE_ID_VIA_8237, NULL);
if (dev != NULL) {
/* Set transition time to max */
pci_read_config_byte(dev, 0xec, &pci_cmd);
pci_cmd &= ~(1 << 2);
pci_write_config_byte(dev, 0xec, pci_cmd);
pci_read_config_byte(dev, 0xe4, &pci_cmd);
pci_cmd &= ~(1 << 7);
pci_write_config_byte(dev, 0xe4, pci_cmd);
pci_read_config_byte(dev, 0xe5, &pci_cmd);
pci_cmd |= 1 << 7;
pci_write_config_byte(dev, 0xe5, pci_cmd);
/* Get address of ACPI registers block*/
pci_read_config_byte(dev, 0x81, &pci_cmd);
if (pci_cmd & 1 << 7) {
pci_read_config_dword(dev, 0x88, &acpi_regs_addr);
acpi_regs_addr &= 0xff00;
printk(KERN_INFO PFX "ACPI I/O at 0x%x\n",
acpi_regs_addr);
}
pci_dev_put(dev);
return 1;
}
return 0;
}
static int __cpuinit longhaul_cpu_init(struct cpufreq_policy *policy)
{
struct cpuinfo_x86 *c = &cpu_data(0);
char *cpuname = NULL;
int ret;
u32 lo, hi;
/* Check what we have on this motherboard */
switch (c->x86_model) {
case 6:
cpu_model = CPU_SAMUEL;
cpuname = "C3 'Samuel' [C5A]";
longhaul_version = TYPE_LONGHAUL_V1;
memcpy(mults, samuel1_mults, sizeof(samuel1_mults));
memcpy(eblcr, samuel1_eblcr, sizeof(samuel1_eblcr));
break;
case 7:
switch (c->x86_mask) {
case 0:
longhaul_version = TYPE_LONGHAUL_V1;
cpu_model = CPU_SAMUEL2;
cpuname = "C3 'Samuel 2' [C5B]";
/* Note, this is not a typo, early Samuel2's had
* Samuel1 ratios. */
memcpy(mults, samuel1_mults, sizeof(samuel1_mults));
memcpy(eblcr, samuel2_eblcr, sizeof(samuel2_eblcr));
break;
case 1 ... 15:
longhaul_version = TYPE_LONGHAUL_V2;
if (c->x86_mask < 8) {
cpu_model = CPU_SAMUEL2;
cpuname = "C3 'Samuel 2' [C5B]";
} else {
cpu_model = CPU_EZRA;
cpuname = "C3 'Ezra' [C5C]";
}
memcpy(mults, ezra_mults, sizeof(ezra_mults));
memcpy(eblcr, ezra_eblcr, sizeof(ezra_eblcr));
break;
}
break;
case 8:
cpu_model = CPU_EZRA_T;
cpuname = "C3 'Ezra-T' [C5M]";
longhaul_version = TYPE_POWERSAVER;
numscales = 32;
memcpy(mults, ezrat_mults, sizeof(ezrat_mults));
memcpy(eblcr, ezrat_eblcr, sizeof(ezrat_eblcr));
break;
case 9:
longhaul_version = TYPE_POWERSAVER;
numscales = 32;
memcpy(mults, nehemiah_mults, sizeof(nehemiah_mults));
memcpy(eblcr, nehemiah_eblcr, sizeof(nehemiah_eblcr));
switch (c->x86_mask) {
case 0 ... 1:
cpu_model = CPU_NEHEMIAH;
cpuname = "C3 'Nehemiah A' [C5XLOE]";
break;
case 2 ... 4:
cpu_model = CPU_NEHEMIAH;
cpuname = "C3 'Nehemiah B' [C5XLOH]";
break;
case 5 ... 15:
cpu_model = CPU_NEHEMIAH_C;
cpuname = "C3 'Nehemiah C' [C5P]";
break;
}
break;
default:
cpuname = "Unknown";
break;
}
/* Check Longhaul ver. 2 */
if (longhaul_version == TYPE_LONGHAUL_V2) {
rdmsr(MSR_VIA_LONGHAUL, lo, hi);
if (lo == 0 && hi == 0)
/* Looks like MSR isn't present */
longhaul_version = TYPE_LONGHAUL_V1;
}
printk(KERN_INFO PFX "VIA %s CPU detected. ", cpuname);
switch (longhaul_version) {
case TYPE_LONGHAUL_V1:
case TYPE_LONGHAUL_V2:
printk(KERN_CONT "Longhaul v%d supported.\n", longhaul_version);
break;
case TYPE_POWERSAVER:
printk(KERN_CONT "Powersaver supported.\n");
break;
};
/* Doesn't hurt */
longhaul_setup_southbridge();
/* Find ACPI data for processor */
acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX, &longhaul_walk_callback, NULL,
NULL, (void *)&pr);
/* Check ACPI support for C3 state */
if (pr != NULL && longhaul_version == TYPE_POWERSAVER) {
cx = &pr->power.states[ACPI_STATE_C3];
if (cx->address > 0 && cx->latency <= 1000)
longhaul_flags |= USE_ACPI_C3;
}
/* Disable if it isn't working */
if (disable_acpi_c3)
longhaul_flags &= ~USE_ACPI_C3;
/* Check if northbridge is friendly */
if (enable_arbiter_disable())
longhaul_flags |= USE_NORTHBRIDGE;
/* Check ACPI support for bus master arbiter disable */
if (!(longhaul_flags & USE_ACPI_C3
|| longhaul_flags & USE_NORTHBRIDGE)
&& ((pr == NULL) || !(pr->flags.bm_control))) {
printk(KERN_ERR PFX
"No ACPI support. Unsupported northbridge.\n");
return -ENODEV;
}
if (longhaul_flags & USE_NORTHBRIDGE)
printk(KERN_INFO PFX "Using northbridge support.\n");
if (longhaul_flags & USE_ACPI_C3)
printk(KERN_INFO PFX "Using ACPI support.\n");
ret = longhaul_get_ranges();
if (ret != 0)
return ret;
if ((longhaul_version != TYPE_LONGHAUL_V1) && (scale_voltage != 0))
longhaul_setup_voltagescaling();
policy->cpuinfo.transition_latency = 200000; /* nsec */
policy->cur = calc_speed(longhaul_get_cpu_mult());
ret = cpufreq_frequency_table_cpuinfo(policy, longhaul_table);
if (ret)
return ret;
cpufreq_frequency_table_get_attr(longhaul_table, policy->cpu);
return 0;
}
static int longhaul_cpu_exit(struct cpufreq_policy *policy)
{
cpufreq_frequency_table_put_attr(policy->cpu);
return 0;
}
static struct freq_attr *longhaul_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
};
static struct cpufreq_driver longhaul_driver = {
.verify = longhaul_verify,
.target = longhaul_target,
.get = longhaul_get,
.init = longhaul_cpu_init,
.exit = longhaul_cpu_exit,
.name = "longhaul",
.owner = THIS_MODULE,
.attr = longhaul_attr,
};
static const struct x86_cpu_id longhaul_id[] = {
{ X86_VENDOR_CENTAUR, 6 },
{}
};
MODULE_DEVICE_TABLE(x86cpu, longhaul_id);
static int __init longhaul_init(void)
{
struct cpuinfo_x86 *c = &cpu_data(0);
if (!x86_match_cpu(longhaul_id))
return -ENODEV;
if (!enable) {
printk(KERN_ERR PFX "Option \"enable\" not set. Aborting.\n");
return -ENODEV;
}
#ifdef CONFIG_SMP
if (num_online_cpus() > 1) {
printk(KERN_ERR PFX "More than 1 CPU detected, "
"longhaul disabled.\n");
return -ENODEV;
}
#endif
#ifdef CONFIG_X86_IO_APIC
if (cpu_has_apic) {
printk(KERN_ERR PFX "APIC detected. Longhaul is currently "
"broken in this configuration.\n");
return -ENODEV;
}
#endif
switch (c->x86_model) {
case 6 ... 9:
return cpufreq_register_driver(&longhaul_driver);
case 10:
printk(KERN_ERR PFX "Use acpi-cpufreq driver for VIA C7\n");
default:
;
}
return -ENODEV;
}
static void __exit longhaul_exit(void)
{
int i;
for (i = 0; i < numscales; i++) {
if (mults[i] == maxmult) {
longhaul_setstate(i);
break;
}
}
cpufreq_unregister_driver(&longhaul_driver);
kfree(longhaul_table);
}
/* Even if BIOS is exporting ACPI C3 state, and it is used
* with success when CPU is idle, this state doesn't
* trigger frequency transition in some cases. */
module_param(disable_acpi_c3, int, 0644);
MODULE_PARM_DESC(disable_acpi_c3, "Don't use ACPI C3 support");
/* Change CPU voltage with frequency. Very useful to save
* power, but most VIA C3 processors aren't supporting it. */
module_param(scale_voltage, int, 0644);
MODULE_PARM_DESC(scale_voltage, "Scale voltage of processor");
/* Force revision key to 0 for processors which doesn't
* support voltage scaling, but are introducing itself as
* such. */
module_param(revid_errata, int, 0644);
MODULE_PARM_DESC(revid_errata, "Ignore CPU Revision ID");
/* By default driver is disabled to prevent incompatible
* system freeze. */
module_param(enable, int, 0644);
MODULE_PARM_DESC(enable, "Enable driver");
MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
MODULE_DESCRIPTION("Longhaul driver for VIA Cyrix processors.");
MODULE_LICENSE("GPL");
late_initcall(longhaul_init);
module_exit(longhaul_exit);