Commit 7f6060e8 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds

[PATCH] fix up CPU detection in p4-clockmod

From: Dominik Brodowski <linux@dominikbrodowski.de>

Too many users use the p4-clockmod cpufreq driver instead of the more
advanced speedstep-centrino, speedstep-ich or even acpi drivers.  All of
the latter (usually) provide voltage scaling, while the p4-clockmod driver
only offers a variant of frequency scaling.  So, warn users if they try out
this driver instead.

Also, instead of using a local copy, use the speedstep_lib infrastructure
for detecting the processor speed.  Adding the Pentium-M get_frequency
function to that module only costs about 200 bytes in object size.
parent 6dd6551e
......@@ -145,11 +145,6 @@ config X86_SPEEDSTEP_SMI
If in doubt, say N.
config X86_SPEEDSTEP_LIB
tristate
depends on (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI)
default (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI)
config X86_P4_CLOCKMOD
tristate "Intel Pentium 4 clock modulation"
depends on CPU_FREQ_TABLE
......@@ -161,6 +156,11 @@ config X86_P4_CLOCKMOD
If in doubt, say N.
config X86_SPEEDSTEP_LIB
tristate
depends on (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD)
default (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD)
config X86_LONGRUN
tristate "Transmeta LongRun"
depends on CPU_FREQ
......
......@@ -33,6 +33,8 @@
#include <asm/msr.h>
#include <asm/timex.h>
#include "speedstep-lib.h"
#define PFX "cpufreq: "
/*
......@@ -174,51 +176,30 @@ static int cpufreq_p4_verify(struct cpufreq_policy *policy)
return cpufreq_frequency_table_verify(policy, &p4clockmod_table[0]);
}
/* copied from speedstep_lib, made SMP-compatible */
static unsigned int cpufreq_p4_get_frequency(struct cpuinfo_x86 *c)
{
u32 msr_lo, msr_hi, mult;
unsigned int fsb = 0;
if ((c->x86 == 0x06) && (c->x86_model == 0x09)) {
/* Pentium M */
printk(KERN_DEBUG PFX "Warning: Pentium M detected. The speedstep_centrino module\n");
printk(KERN_DEBUG PFX "offers voltage scaling in addition of frequency scaling. You\n");
printk(KERN_DEBUG PFX "should use that instead of p4-clockmod, if possible.\n");
return speedstep_get_processor_frequency(SPEEDSTEP_PROCESSOR_PM);
}
if (c->x86 != 0xF) {
printk(KERN_DEBUG PFX "Unknown P4. Please send an e-mail to <linux@brodo.de>\n");
printk(KERN_DEBUG PFX "Unknown p4-clockmod-capable CPU. Please send an e-mail to <linux@brodo.de>\n");
return 0;
}
rdmsr(0x2c, msr_lo, msr_hi);
/* printk(KERN_DEBUG PFX "P4 - MSR_EBC_FREQUENCY_ID: 0x%x 0x%x\n", msr_lo, msr_hi); */
/* decode the FSB: see IA-32 Intel (C) Architecture Software
* Developer's Manual, Volume 3: System Prgramming Guide,
* revision #12 in Table B-1: MSRs in the Pentium 4 and
* Intel Xeon Processors, on page B-4 and B-5.
*/
if (c->x86_model < 2)
fsb = 100 * 1000;
else {
u8 fsb_code = (msr_lo >> 16) & 0x7;
switch (fsb_code) {
case 0:
fsb = 100 * 1000;
break;
case 1:
fsb = 13333 * 10;
break;
case 2:
fsb = 200 * 1000;
break;
}
}
if (!fsb) {
printk(KERN_DEBUG PFX "couldn't detect FSB speed. Please send an e-mail to <linux@brodo.de>\n");
printk(KERN_DEBUG PFX "P4 - MSR_EBC_FREQUENCY_ID: 0x%x 0x%x\n", msr_lo, msr_hi);
if (speedstep_detect_processor() == SPEEDSTEP_PROCESSOR_P4M) {
printk(KERN_DEBUG PFX "Warning: Pentium 4-M detected. The speedstep-ich or acpi cpufreq \n");
printk(KERN_DEBUG PFX "modules offers voltage scaling in addition of frequency scaling. You\n");
printk(KERN_DEBUG PFX "should use either one instead of p4-clockmod, if possible.\n");
return speedstep_get_processor_frequency(SPEEDSTEP_PROCESSOR_P4M);
}
/* Multiplier. */
mult = msr_lo >> 24;
return (fsb * mult);
return speedstep_get_processor_frequency(SPEEDSTEP_PROCESSOR_P4D);
}
......@@ -315,6 +296,6 @@ MODULE_AUTHOR ("Zwane Mwaikambo <zwane@commfireservices.com>");
MODULE_DESCRIPTION ("cpufreq driver for Pentium(TM) 4/Xeon(TM)");
MODULE_LICENSE ("GPL");
module_init(cpufreq_p4_init);
late_initcall(cpufreq_p4_init);
module_exit(cpufreq_p4_exit);
......@@ -104,6 +104,26 @@ static unsigned int pentium3_get_frequency (unsigned int processor)
}
static unsigned int pentiumM_get_frequency(void)
{
u32 msr_lo, msr_tmp;
rdmsr(MSR_IA32_EBL_CR_POWERON, msr_lo, msr_tmp);
dprintk(KERN_DEBUG "speedstep-lib: PM - MSR_IA32_EBL_CR_POWERON: 0x%x 0x%x\n", msr_lo, msr_tmp);
/* see table B-2 of 24547212.pdf */
if (msr_lo & 0x00040000) {
printk(KERN_DEBUG "speedstep-lib: PM - invalid FSB: 0x%x 0x%x\n", msr_lo, msr_tmp);
return 0;
}
msr_tmp = (msr_lo >> 22) & 0x1f;
dprintk(KERN_DEBUG "speedstep-lib: bits 22-26 are 0x%x\n", msr_tmp);
return (msr_tmp * 100 * 10000);
}
static unsigned int pentium4_get_frequency(void)
{
struct cpuinfo_x86 *c = &boot_cpu_data;
......@@ -151,6 +171,9 @@ static unsigned int pentium4_get_frequency(void)
unsigned int speedstep_get_processor_frequency(unsigned int processor)
{
switch (processor) {
case SPEEDSTEP_PROCESSOR_PM:
return pentiumM_get_frequency();
case SPEEDSTEP_PROCESSOR_P4D:
case SPEEDSTEP_PROCESSOR_P4M:
return pentium4_get_frequency();
case SPEEDSTEP_PROCESSOR_PIII_T:
......
......@@ -17,6 +17,12 @@
#define SPEEDSTEP_PROCESSOR_PIII_T 0x00000003 /* Tualatin core */
#define SPEEDSTEP_PROCESSOR_P4M 0x00000004 /* P4-M */
/* the following processors are not speedstep-capable and are not auto-detected
* in speedstep_detect_processor(). However, their speed can be detected using
* the speedstep_get_processor_frequency() call. */
#define SPEEDSTEP_PROCESSOR_PM 0xFFFFFF03 /* Pentium M */
#define SPEEDSTEP_PROCESSOR_P4D 0xFFFFFF04 /* desktop P4 */
/* speedstep states -- only two of them */
#define SPEEDSTEP_HIGH 0x00000000
......
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