leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity
f2d022aa42
linux/drivers/cpufreq/powernow-k6.c
Viresh Kumar 7f4b04614a cpufreq: create another field .flags in cpufreq_frequency_table 
Currently cpufreq frequency table has two fields: frequency and driver_data.
driver_data is only for drivers' internal use and cpufreq core shouldn't use
it at all. But with the introduction of BOOST frequencies, this assumption
was broken and we started using it as a flag instead.

There are two problems due to this:
- It is against the description of this field, as driver's data is used by
  the core now.
- if drivers fill it with -3 for any frequency, then those frequencies are
  never considered by cpufreq core as it is exactly same as value of
  CPUFREQ_BOOST_FREQ, i.e. ~2.

The best way to get this fixed is by creating another field flags which
will be used for such flags. This patch does that. Along with that various
drivers need modifications due to the change of struct cpufreq_frequency_table.

Reviewed-by: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-07 14:43:50 +02:00

306 lines
8.1 KiB
C
Raw Blame History

/*
* This file was based upon code in Powertweak Linux (http://powertweak.sf.net)
* (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä,
* Dominik Brodowski.
*
* 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/cpufreq.h>
#include <linux/ioport.h>
#include <linux/timex.h>
#include <linux/io.h>
#include <asm/cpu_device_id.h>
#include <asm/msr.h>
#define POWERNOW_IOPORT 0xfff0 /* it doesn't matter where, as long
as it is unused */
#define PFX "powernow-k6: "
static unsigned int busfreq; /* FSB, in 10 kHz */
static unsigned int max_multiplier;
static unsigned int param_busfreq = 0;
static unsigned int param_max_multiplier = 0;
module_param_named(max_multiplier, param_max_multiplier, uint, S_IRUGO);
MODULE_PARM_DESC(max_multiplier, "Maximum multiplier (allowed values: 20 30 35 40 45 50 55 60)");
module_param_named(bus_frequency, param_busfreq, uint, S_IRUGO);
MODULE_PARM_DESC(bus_frequency, "Bus frequency in kHz");
/* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */
static struct cpufreq_frequency_table clock_ratio[] = {
{0, 60, /* 110 -> 6.0x */ 0},
{0, 55, /* 011 -> 5.5x */ 0},
{0, 50, /* 001 -> 5.0x */ 0},
{0, 45, /* 000 -> 4.5x */ 0},
{0, 40, /* 010 -> 4.0x */ 0},
{0, 35, /* 111 -> 3.5x */ 0},
{0, 30, /* 101 -> 3.0x */ 0},
{0, 20, /* 100 -> 2.0x */ 0},
{0, 0, CPUFREQ_TABLE_END}
};
static const u8 index_to_register[8] = { 6, 3, 1, 0, 2, 7, 5, 4 };
static const u8 register_to_index[8] = { 3, 2, 4, 1, 7, 6, 0, 5 };
static const struct {
unsigned freq;
unsigned mult;
} usual_frequency_table[] = {
{ 400000, 40 }, // 100 * 4
{ 450000, 45 }, // 100 * 4.5
{ 475000, 50 }, // 95 * 5
{ 500000, 50 }, // 100 * 5
{ 506250, 45 }, // 112.5 * 4.5
{ 533500, 55 }, // 97 * 5.5
{ 550000, 55 }, // 100 * 5.5
{ 562500, 50 }, // 112.5 * 5
{ 570000, 60 }, // 95 * 6
{ 600000, 60 }, // 100 * 6
{ 618750, 55 }, // 112.5 * 5.5
{ 660000, 55 }, // 120 * 5.5
{ 675000, 60 }, // 112.5 * 6
{ 720000, 60 }, // 120 * 6
};
#define FREQ_RANGE 3000
/**
* powernow_k6_get_cpu_multiplier - returns the current FSB multiplier
*
* Returns the current setting of the frequency multiplier. Core clock
* speed is frequency of the Front-Side Bus multiplied with this value.
*/
static int powernow_k6_get_cpu_multiplier(void)
{
unsigned long invalue = 0;
u32 msrval;
local_irq_disable();
msrval = POWERNOW_IOPORT + 0x1;
wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
invalue = inl(POWERNOW_IOPORT + 0x8);
msrval = POWERNOW_IOPORT + 0x0;
wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
local_irq_enable();
return clock_ratio[register_to_index[(invalue >> 5)&7]].driver_data;
}
static void powernow_k6_set_cpu_multiplier(unsigned int best_i)
{
unsigned long outvalue, invalue;
unsigned long msrval;
unsigned long cr0;
/* we now need to transform best_i to the BVC format, see AMD#23446 */
/*
* The processor doesn't respond to inquiry cycles while changing the
* frequency, so we must disable cache.
*/
local_irq_disable();
cr0 = read_cr0();
write_cr0(cr0 | X86_CR0_CD);
wbinvd();
outvalue = (1<<12) | (1<<10) | (1<<9) | (index_to_register[best_i]<<5);
msrval = POWERNOW_IOPORT + 0x1;
wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
invalue = inl(POWERNOW_IOPORT + 0x8);
invalue = invalue & 0x1f;
outvalue = outvalue | invalue;
outl(outvalue, (POWERNOW_IOPORT + 0x8));
msrval = POWERNOW_IOPORT + 0x0;
wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
write_cr0(cr0);
local_irq_enable();
}
/**
* powernow_k6_target - set the PowerNow! multiplier
* @best_i: clock_ratio[best_i] is the target multiplier
*
* Tries to change the PowerNow! multiplier
*/
static int powernow_k6_target(struct cpufreq_policy *policy,
unsigned int best_i)
{
struct cpufreq_freqs freqs;
if (clock_ratio[best_i].driver_data > max_multiplier) {
printk(KERN_ERR PFX "invalid target frequency\n");
return -EINVAL;
}
freqs.old = busfreq * powernow_k6_get_cpu_multiplier();
freqs.new = busfreq * clock_ratio[best_i].driver_data;
cpufreq_freq_transition_begin(policy, &freqs);
powernow_k6_set_cpu_multiplier(best_i);
cpufreq_freq_transition_end(policy, &freqs, 0);
return 0;
}
static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
{
unsigned int i, f;
unsigned khz;
if (policy->cpu != 0)
return -ENODEV;
max_multiplier = 0;
khz = cpu_khz;
for (i = 0; i < ARRAY_SIZE(usual_frequency_table); i++) {
if (khz >= usual_frequency_table[i].freq - FREQ_RANGE &&
khz <= usual_frequency_table[i].freq + FREQ_RANGE) {
khz = usual_frequency_table[i].freq;
max_multiplier = usual_frequency_table[i].mult;
break;
}
}
if (param_max_multiplier) {
for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
if (clock_ratio[i].driver_data == param_max_multiplier) {
max_multiplier = param_max_multiplier;
goto have_max_multiplier;
}
}
printk(KERN_ERR "powernow-k6: invalid max_multiplier parameter, valid parameters 20, 30, 35, 40, 45, 50, 55, 60\n");
return -EINVAL;
}
if (!max_multiplier) {
printk(KERN_WARNING "powernow-k6: unknown frequency %u, cannot determine current multiplier\n", khz);
printk(KERN_WARNING "powernow-k6: use module parameters max_multiplier and bus_frequency\n");
return -EOPNOTSUPP;
}
have_max_multiplier:
param_max_multiplier = max_multiplier;
if (param_busfreq) {
if (param_busfreq >= 50000 && param_busfreq <= 150000) {
busfreq = param_busfreq / 10;
goto have_busfreq;
}
printk(KERN_ERR "powernow-k6: invalid bus_frequency parameter, allowed range 50000 - 150000 kHz\n");
return -EINVAL;
}
busfreq = khz / max_multiplier;
have_busfreq:
param_busfreq = busfreq * 10;
/* table init */
for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
f = clock_ratio[i].driver_data;
if (f > max_multiplier)
clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID;
else
clock_ratio[i].frequency = busfreq * f;
}
/* cpuinfo and default policy values */
policy->cpuinfo.transition_latency = 500000;
return cpufreq_table_validate_and_show(policy, clock_ratio);
}
static int powernow_k6_cpu_exit(struct cpufreq_policy *policy)
{
unsigned int i;
for (i = 0; i < 8; i++) {
if (i == max_multiplier)
powernow_k6_target(policy, i);
}
return 0;
}
static unsigned int powernow_k6_get(unsigned int cpu)
{
unsigned int ret;
ret = (busfreq * powernow_k6_get_cpu_multiplier());
return ret;
}
static struct cpufreq_driver powernow_k6_driver = {
.verify = cpufreq_generic_frequency_table_verify,
.target_index = powernow_k6_target,
.init = powernow_k6_cpu_init,
.exit = powernow_k6_cpu_exit,
.get = powernow_k6_get,
.name = "powernow-k6",
.attr = cpufreq_generic_attr,
};
static const struct x86_cpu_id powernow_k6_ids[] = {
{ X86_VENDOR_AMD, 5, 12 },
{ X86_VENDOR_AMD, 5, 13 },
{}
};
MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids);
/**
* powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver
*
* Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported
* devices, -EINVAL or -ENOMEM on problems during initiatization, and zero
* on success.
*/
static int __init powernow_k6_init(void)
{
if (!x86_match_cpu(powernow_k6_ids))
return -ENODEV;
if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n");
return -EIO;
}
if (cpufreq_register_driver(&powernow_k6_driver)) {
release_region(POWERNOW_IOPORT, 16);
return -EINVAL;
}
return 0;
}
/**
* powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support
*
* Unregisters AMD K6-2+ / K6-3+ PowerNow! support.
*/
static void __exit powernow_k6_exit(void)
{
cpufreq_unregister_driver(&powernow_k6_driver);
release_region(POWERNOW_IOPORT, 16);
}
MODULE_AUTHOR("Arjan van de Ven, Dave Jones <davej@redhat.com>, "
"Dominik Brodowski <linux@brodo.de>");
MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
MODULE_LICENSE("GPL");
module_init(powernow_k6_init);
module_exit(powernow_k6_exit);
Reference in New Issue View Git Blame Copy Permalink