mirror of
https://github.com/torvalds/linux.git
synced 2024-11-08 21:21:47 +00:00
ee580dc91e
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
326 lines
8.3 KiB
C
326 lines
8.3 KiB
C
/*
|
|
* (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
|
|
*
|
|
* Licensed under the terms of the GNU GPL License version 2.
|
|
*
|
|
* BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/cpufreq.h>
|
|
|
|
#include <asm/msr.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/timex.h>
|
|
|
|
#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "longrun", msg)
|
|
|
|
static struct cpufreq_driver longrun_driver;
|
|
|
|
/**
|
|
* longrun_{low,high}_freq is needed for the conversion of cpufreq kHz
|
|
* values into per cent values. In TMTA microcode, the following is valid:
|
|
* performance_pctg = (current_freq - low_freq)/(high_freq - low_freq)
|
|
*/
|
|
static unsigned int longrun_low_freq, longrun_high_freq;
|
|
|
|
|
|
/**
|
|
* longrun_get_policy - get the current LongRun policy
|
|
* @policy: struct cpufreq_policy where current policy is written into
|
|
*
|
|
* Reads the current LongRun policy by access to MSR_TMTA_LONGRUN_FLAGS
|
|
* and MSR_TMTA_LONGRUN_CTRL
|
|
*/
|
|
static void __init longrun_get_policy(struct cpufreq_policy *policy)
|
|
{
|
|
u32 msr_lo, msr_hi;
|
|
|
|
rdmsr(MSR_TMTA_LONGRUN_FLAGS, msr_lo, msr_hi);
|
|
dprintk("longrun flags are %x - %x\n", msr_lo, msr_hi);
|
|
if (msr_lo & 0x01)
|
|
policy->policy = CPUFREQ_POLICY_PERFORMANCE;
|
|
else
|
|
policy->policy = CPUFREQ_POLICY_POWERSAVE;
|
|
|
|
rdmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
|
|
dprintk("longrun ctrl is %x - %x\n", msr_lo, msr_hi);
|
|
msr_lo &= 0x0000007F;
|
|
msr_hi &= 0x0000007F;
|
|
|
|
if ( longrun_high_freq <= longrun_low_freq ) {
|
|
/* Assume degenerate Longrun table */
|
|
policy->min = policy->max = longrun_high_freq;
|
|
} else {
|
|
policy->min = longrun_low_freq + msr_lo *
|
|
((longrun_high_freq - longrun_low_freq) / 100);
|
|
policy->max = longrun_low_freq + msr_hi *
|
|
((longrun_high_freq - longrun_low_freq) / 100);
|
|
}
|
|
policy->cpu = 0;
|
|
}
|
|
|
|
|
|
/**
|
|
* longrun_set_policy - sets a new CPUFreq policy
|
|
* @policy: new policy
|
|
*
|
|
* Sets a new CPUFreq policy on LongRun-capable processors. This function
|
|
* has to be called with cpufreq_driver locked.
|
|
*/
|
|
static int longrun_set_policy(struct cpufreq_policy *policy)
|
|
{
|
|
u32 msr_lo, msr_hi;
|
|
u32 pctg_lo, pctg_hi;
|
|
|
|
if (!policy)
|
|
return -EINVAL;
|
|
|
|
if ( longrun_high_freq <= longrun_low_freq ) {
|
|
/* Assume degenerate Longrun table */
|
|
pctg_lo = pctg_hi = 100;
|
|
} else {
|
|
pctg_lo = (policy->min - longrun_low_freq) /
|
|
((longrun_high_freq - longrun_low_freq) / 100);
|
|
pctg_hi = (policy->max - longrun_low_freq) /
|
|
((longrun_high_freq - longrun_low_freq) / 100);
|
|
}
|
|
|
|
if (pctg_hi > 100)
|
|
pctg_hi = 100;
|
|
if (pctg_lo > pctg_hi)
|
|
pctg_lo = pctg_hi;
|
|
|
|
/* performance or economy mode */
|
|
rdmsr(MSR_TMTA_LONGRUN_FLAGS, msr_lo, msr_hi);
|
|
msr_lo &= 0xFFFFFFFE;
|
|
switch (policy->policy) {
|
|
case CPUFREQ_POLICY_PERFORMANCE:
|
|
msr_lo |= 0x00000001;
|
|
break;
|
|
case CPUFREQ_POLICY_POWERSAVE:
|
|
break;
|
|
}
|
|
wrmsr(MSR_TMTA_LONGRUN_FLAGS, msr_lo, msr_hi);
|
|
|
|
/* lower and upper boundary */
|
|
rdmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
|
|
msr_lo &= 0xFFFFFF80;
|
|
msr_hi &= 0xFFFFFF80;
|
|
msr_lo |= pctg_lo;
|
|
msr_hi |= pctg_hi;
|
|
wrmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/**
|
|
* longrun_verify_poliy - verifies a new CPUFreq policy
|
|
* @policy: the policy to verify
|
|
*
|
|
* Validates a new CPUFreq policy. This function has to be called with
|
|
* cpufreq_driver locked.
|
|
*/
|
|
static int longrun_verify_policy(struct cpufreq_policy *policy)
|
|
{
|
|
if (!policy)
|
|
return -EINVAL;
|
|
|
|
policy->cpu = 0;
|
|
cpufreq_verify_within_limits(policy,
|
|
policy->cpuinfo.min_freq,
|
|
policy->cpuinfo.max_freq);
|
|
|
|
if ((policy->policy != CPUFREQ_POLICY_POWERSAVE) &&
|
|
(policy->policy != CPUFREQ_POLICY_PERFORMANCE))
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int longrun_get(unsigned int cpu)
|
|
{
|
|
u32 eax, ebx, ecx, edx;
|
|
|
|
if (cpu)
|
|
return 0;
|
|
|
|
cpuid(0x80860007, &eax, &ebx, &ecx, &edx);
|
|
dprintk("cpuid eax is %u\n", eax);
|
|
|
|
return (eax * 1000);
|
|
}
|
|
|
|
/**
|
|
* longrun_determine_freqs - determines the lowest and highest possible core frequency
|
|
* @low_freq: an int to put the lowest frequency into
|
|
* @high_freq: an int to put the highest frequency into
|
|
*
|
|
* Determines the lowest and highest possible core frequencies on this CPU.
|
|
* This is necessary to calculate the performance percentage according to
|
|
* TMTA rules:
|
|
* performance_pctg = (target_freq - low_freq)/(high_freq - low_freq)
|
|
*/
|
|
static unsigned int __init longrun_determine_freqs(unsigned int *low_freq,
|
|
unsigned int *high_freq)
|
|
{
|
|
u32 msr_lo, msr_hi;
|
|
u32 save_lo, save_hi;
|
|
u32 eax, ebx, ecx, edx;
|
|
u32 try_hi;
|
|
struct cpuinfo_x86 *c = cpu_data;
|
|
|
|
if (!low_freq || !high_freq)
|
|
return -EINVAL;
|
|
|
|
if (cpu_has(c, X86_FEATURE_LRTI)) {
|
|
/* if the LongRun Table Interface is present, the
|
|
* detection is a bit easier:
|
|
* For minimum frequency, read out the maximum
|
|
* level (msr_hi), write that into "currently
|
|
* selected level", and read out the frequency.
|
|
* For maximum frequency, read out level zero.
|
|
*/
|
|
/* minimum */
|
|
rdmsr(MSR_TMTA_LRTI_READOUT, msr_lo, msr_hi);
|
|
wrmsr(MSR_TMTA_LRTI_READOUT, msr_hi, msr_hi);
|
|
rdmsr(MSR_TMTA_LRTI_VOLT_MHZ, msr_lo, msr_hi);
|
|
*low_freq = msr_lo * 1000; /* to kHz */
|
|
|
|
/* maximum */
|
|
wrmsr(MSR_TMTA_LRTI_READOUT, 0, msr_hi);
|
|
rdmsr(MSR_TMTA_LRTI_VOLT_MHZ, msr_lo, msr_hi);
|
|
*high_freq = msr_lo * 1000; /* to kHz */
|
|
|
|
dprintk("longrun table interface told %u - %u kHz\n", *low_freq, *high_freq);
|
|
|
|
if (*low_freq > *high_freq)
|
|
*low_freq = *high_freq;
|
|
return 0;
|
|
}
|
|
|
|
/* set the upper border to the value determined during TSC init */
|
|
*high_freq = (cpu_khz / 1000);
|
|
*high_freq = *high_freq * 1000;
|
|
dprintk("high frequency is %u kHz\n", *high_freq);
|
|
|
|
/* get current borders */
|
|
rdmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
|
|
save_lo = msr_lo & 0x0000007F;
|
|
save_hi = msr_hi & 0x0000007F;
|
|
|
|
/* if current perf_pctg is larger than 90%, we need to decrease the
|
|
* upper limit to make the calculation more accurate.
|
|
*/
|
|
cpuid(0x80860007, &eax, &ebx, &ecx, &edx);
|
|
/* try decreasing in 10% steps, some processors react only
|
|
* on some barrier values */
|
|
for (try_hi = 80; try_hi > 0 && ecx > 90; try_hi -=10) {
|
|
/* set to 0 to try_hi perf_pctg */
|
|
msr_lo &= 0xFFFFFF80;
|
|
msr_hi &= 0xFFFFFF80;
|
|
msr_hi |= try_hi;
|
|
wrmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
|
|
|
|
/* read out current core MHz and current perf_pctg */
|
|
cpuid(0x80860007, &eax, &ebx, &ecx, &edx);
|
|
|
|
/* restore values */
|
|
wrmsr(MSR_TMTA_LONGRUN_CTRL, save_lo, save_hi);
|
|
}
|
|
dprintk("percentage is %u %%, freq is %u MHz\n", ecx, eax);
|
|
|
|
/* performance_pctg = (current_freq - low_freq)/(high_freq - low_freq)
|
|
* eqals
|
|
* low_freq * ( 1 - perf_pctg) = (cur_freq - high_freq * perf_pctg)
|
|
*
|
|
* high_freq * perf_pctg is stored tempoarily into "ebx".
|
|
*/
|
|
ebx = (((cpu_khz / 1000) * ecx) / 100); /* to MHz */
|
|
|
|
if ((ecx > 95) || (ecx == 0) || (eax < ebx))
|
|
return -EIO;
|
|
|
|
edx = (eax - ebx) / (100 - ecx);
|
|
*low_freq = edx * 1000; /* back to kHz */
|
|
|
|
dprintk("low frequency is %u kHz\n", *low_freq);
|
|
|
|
if (*low_freq > *high_freq)
|
|
*low_freq = *high_freq;
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int __init longrun_cpu_init(struct cpufreq_policy *policy)
|
|
{
|
|
int result = 0;
|
|
|
|
/* capability check */
|
|
if (policy->cpu != 0)
|
|
return -ENODEV;
|
|
|
|
/* detect low and high frequency */
|
|
result = longrun_determine_freqs(&longrun_low_freq, &longrun_high_freq);
|
|
if (result)
|
|
return result;
|
|
|
|
/* cpuinfo and default policy values */
|
|
policy->cpuinfo.min_freq = longrun_low_freq;
|
|
policy->cpuinfo.max_freq = longrun_high_freq;
|
|
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
|
|
longrun_get_policy(policy);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static struct cpufreq_driver longrun_driver = {
|
|
.flags = CPUFREQ_CONST_LOOPS,
|
|
.verify = longrun_verify_policy,
|
|
.setpolicy = longrun_set_policy,
|
|
.get = longrun_get,
|
|
.init = longrun_cpu_init,
|
|
.name = "longrun",
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
|
|
/**
|
|
* longrun_init - initializes the Transmeta Crusoe LongRun CPUFreq driver
|
|
*
|
|
* Initializes the LongRun support.
|
|
*/
|
|
static int __init longrun_init(void)
|
|
{
|
|
struct cpuinfo_x86 *c = cpu_data;
|
|
|
|
if (c->x86_vendor != X86_VENDOR_TRANSMETA ||
|
|
!cpu_has(c, X86_FEATURE_LONGRUN))
|
|
return -ENODEV;
|
|
|
|
return cpufreq_register_driver(&longrun_driver);
|
|
}
|
|
|
|
|
|
/**
|
|
* longrun_exit - unregisters LongRun support
|
|
*/
|
|
static void __exit longrun_exit(void)
|
|
{
|
|
cpufreq_unregister_driver(&longrun_driver);
|
|
}
|
|
|
|
|
|
MODULE_AUTHOR ("Dominik Brodowski <linux@brodo.de>");
|
|
MODULE_DESCRIPTION ("LongRun driver for Transmeta Crusoe and Efficeon processors.");
|
|
MODULE_LICENSE ("GPL");
|
|
|
|
module_init(longrun_init);
|
|
module_exit(longrun_exit);
|