linux-stable/drivers/cpufreq/p4-clockmod.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Pentium 4/Xeon CPU on demand clock modulation/speed scaling
* (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
* (C) 2002 Zwane Mwaikambo <zwane@commfireservices.com>
* (C) 2002 Arjan van de Ven <arjanv@redhat.com>
* (C) 2002 Tora T. Engstad
* All Rights Reserved
*
* The author(s) of this software shall not be held liable for damages
* of any nature resulting due to the use of this software. This
* software is provided AS-IS with no warranties.
*
* Date Errata Description
* 20020525 N44, O17 12.5% or 25% DC causes lockup
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/timex.h>
#include <asm/processor.h>
#include <asm/msr.h>
#include <asm/timer.h>
#include <asm/cpu_device_id.h>
#include "speedstep-lib.h"
/*
* Duty Cycle (3bits), note DC_DISABLE is not specified in
* intel docs i just use it to mean disable
*/
enum {
DC_RESV, DC_DFLT, DC_25PT, DC_38PT, DC_50PT,
DC_64PT, DC_75PT, DC_88PT, DC_DISABLE
};
#define DC_ENTRIES 8
static int has_N44_O17_errata[NR_CPUS];
static unsigned int stock_freq;
static struct cpufreq_driver p4clockmod_driver;
static unsigned int cpufreq_p4_get(unsigned int cpu);
static int cpufreq_p4_setdc(unsigned int cpu, unsigned int newstate)
{
u32 l, h;
if ((newstate > DC_DISABLE) || (newstate == DC_RESV))
return -EINVAL;
rdmsr_on_cpu(cpu, MSR_IA32_THERM_STATUS, &l, &h);
if (l & 0x01)
pr_debug("CPU#%d currently thermal throttled\n", cpu);
if (has_N44_O17_errata[cpu] &&
(newstate == DC_25PT || newstate == DC_DFLT))
newstate = DC_38PT;
rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h);
if (newstate == DC_DISABLE) {
pr_debug("CPU#%d disabling modulation\n", cpu);
wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l & ~(1<<4), h);
} else {
pr_debug("CPU#%d setting duty cycle to %d%%\n",
cpu, ((125 * newstate) / 10));
/* bits 63 - 5 : reserved
* bit 4 : enable/disable
* bits 3-1 : duty cycle
* bit 0 : reserved
*/
l = (l & ~14);
l = l | (1<<4) | ((newstate & 0x7)<<1);
wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l, h);
}
return 0;
}
static struct cpufreq_frequency_table p4clockmod_table[] = {
{0, DC_RESV, CPUFREQ_ENTRY_INVALID},
{0, DC_DFLT, 0},
{0, DC_25PT, 0},
{0, DC_38PT, 0},
{0, DC_50PT, 0},
{0, DC_64PT, 0},
{0, DC_75PT, 0},
{0, DC_88PT, 0},
{0, DC_DISABLE, 0},
{0, DC_RESV, CPUFREQ_TABLE_END},
};
cpufreq: Implement light weight ->target_index() routine Currently, the prototype of cpufreq_drivers target routines is: int target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation); And most of the drivers call cpufreq_frequency_table_target() to get a valid index of their frequency table which is closest to the target_freq. And they don't use target_freq and relation after that. So, it makes sense to just do this work in cpufreq core before calling cpufreq_frequency_table_target() and simply pass index instead. But this can be done only with drivers which expose their frequency table with cpufreq core. For others we need to stick with the old prototype of target() until those drivers are converted to expose frequency tables. This patch implements the new light weight prototype for target_index() routine. It looks like this: int target_index(struct cpufreq_policy *policy, unsigned int index); CPUFreq core will call cpufreq_frequency_table_target() before calling this routine and pass index to it. Because CPUFreq core now requires to call routines present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time. This also marks target() interface as deprecated. So, that new drivers avoid using it. And Documentation is updated accordingly. It also converts existing .target() to newly defined light weight .target_index() routine for many driver. Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King <linux@arm.linux.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
2013-10-25 14:15:48 +00:00
static int cpufreq_p4_target(struct cpufreq_policy *policy, unsigned int index)
{
int i;
/* run on each logical CPU,
* see section 13.15.3 of IA32 Intel Architecture Software
* Developer's Manual, Volume 3
*/
for_each_cpu(i, policy->cpus)
cpufreq: Implement light weight ->target_index() routine Currently, the prototype of cpufreq_drivers target routines is: int target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation); And most of the drivers call cpufreq_frequency_table_target() to get a valid index of their frequency table which is closest to the target_freq. And they don't use target_freq and relation after that. So, it makes sense to just do this work in cpufreq core before calling cpufreq_frequency_table_target() and simply pass index instead. But this can be done only with drivers which expose their frequency table with cpufreq core. For others we need to stick with the old prototype of target() until those drivers are converted to expose frequency tables. This patch implements the new light weight prototype for target_index() routine. It looks like this: int target_index(struct cpufreq_policy *policy, unsigned int index); CPUFreq core will call cpufreq_frequency_table_target() before calling this routine and pass index to it. Because CPUFreq core now requires to call routines present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time. This also marks target() interface as deprecated. So, that new drivers avoid using it. And Documentation is updated accordingly. It also converts existing .target() to newly defined light weight .target_index() routine for many driver. Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King <linux@arm.linux.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
2013-10-25 14:15:48 +00:00
cpufreq_p4_setdc(i, p4clockmod_table[index].driver_data);
return 0;
}
static unsigned int cpufreq_p4_get_frequency(struct cpuinfo_x86 *c)
{
if (c->x86 == 0x06) {
if (cpu_has(c, X86_FEATURE_EST))
pr_warn_once("Warning: EST-capable CPU detected. The acpi-cpufreq module offers voltage scaling in addition to frequency scaling. You should use that instead of p4-clockmod, if possible.\n");
switch (c->x86_model) {
case 0x0E: /* Core */
case 0x0F: /* Core Duo */
case 0x16: /* Celeron Core */
case 0x1C: /* Atom */
p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS;
return speedstep_get_frequency(SPEEDSTEP_CPU_PCORE);
case 0x0D: /* Pentium M (Dothan) */
p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS;
fallthrough;
case 0x09: /* Pentium M (Banias) */
return speedstep_get_frequency(SPEEDSTEP_CPU_PM);
}
}
if (c->x86 != 0xF)
return 0;
/* on P-4s, the TSC runs with constant frequency independent whether
* throttling is active or not. */
p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS;
if (speedstep_detect_processor() == SPEEDSTEP_CPU_P4M) {
pr_warn("Warning: Pentium 4-M detected. The speedstep-ich or acpi cpufreq modules offer voltage scaling in addition of frequency scaling. You should use either one instead of p4-clockmod, if possible.\n");
return speedstep_get_frequency(SPEEDSTEP_CPU_P4M);
}
return speedstep_get_frequency(SPEEDSTEP_CPU_P4D);
}
static int cpufreq_p4_cpu_init(struct cpufreq_policy *policy)
{
struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
int cpuid = 0;
unsigned int i;
#ifdef CONFIG_SMP
cpumask_copy(policy->cpus, topology_sibling_cpumask(policy->cpu));
#endif
/* Errata workaround */
cpuid = (c->x86 << 8) | (c->x86_model << 4) | c->x86_stepping;
switch (cpuid) {
case 0x0f07:
case 0x0f0a:
case 0x0f11:
case 0x0f12:
has_N44_O17_errata[policy->cpu] = 1;
pr_debug("has errata -- disabling low frequencies\n");
}
if (speedstep_detect_processor() == SPEEDSTEP_CPU_P4D &&
c->x86_model < 2) {
/* switch to maximum frequency and measure result */
cpufreq_p4_setdc(policy->cpu, DC_DISABLE);
recalibrate_cpu_khz();
}
/* get max frequency */
stock_freq = cpufreq_p4_get_frequency(c);
if (!stock_freq)
return -EINVAL;
/* table init */
for (i = 1; (p4clockmod_table[i].frequency != CPUFREQ_TABLE_END); i++) {
if ((i < 2) && (has_N44_O17_errata[policy->cpu]))
p4clockmod_table[i].frequency = CPUFREQ_ENTRY_INVALID;
else
p4clockmod_table[i].frequency = (stock_freq * i)/8;
}
/* cpuinfo and default policy values */
/* the transition latency is set to be 1 higher than the maximum
* transition latency of the ondemand governor */
policy->cpuinfo.transition_latency = 10000001;
policy->freq_table = &p4clockmod_table[0];
return 0;
}
static unsigned int cpufreq_p4_get(unsigned int cpu)
{
u32 l, h;
rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h);
if (l & 0x10) {
l = l >> 1;
l &= 0x7;
} else
l = DC_DISABLE;
if (l != DC_DISABLE)
return stock_freq * l / 8;
return stock_freq;
}
static struct cpufreq_driver p4clockmod_driver = {
.verify = cpufreq_generic_frequency_table_verify,
cpufreq: Implement light weight ->target_index() routine Currently, the prototype of cpufreq_drivers target routines is: int target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation); And most of the drivers call cpufreq_frequency_table_target() to get a valid index of their frequency table which is closest to the target_freq. And they don't use target_freq and relation after that. So, it makes sense to just do this work in cpufreq core before calling cpufreq_frequency_table_target() and simply pass index instead. But this can be done only with drivers which expose their frequency table with cpufreq core. For others we need to stick with the old prototype of target() until those drivers are converted to expose frequency tables. This patch implements the new light weight prototype for target_index() routine. It looks like this: int target_index(struct cpufreq_policy *policy, unsigned int index); CPUFreq core will call cpufreq_frequency_table_target() before calling this routine and pass index to it. Because CPUFreq core now requires to call routines present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time. This also marks target() interface as deprecated. So, that new drivers avoid using it. And Documentation is updated accordingly. It also converts existing .target() to newly defined light weight .target_index() routine for many driver. Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King <linux@arm.linux.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
2013-10-25 14:15:48 +00:00
.target_index = cpufreq_p4_target,
.init = cpufreq_p4_cpu_init,
.get = cpufreq_p4_get,
.name = "p4-clockmod",
.attr = cpufreq_generic_attr,
};
static const struct x86_cpu_id cpufreq_p4_id[] = {
X86_MATCH_VENDOR_FEATURE(INTEL, X86_FEATURE_ACC, NULL),
{}
};
/*
* Intentionally no MODULE_DEVICE_TABLE here: this driver should not
* be auto loaded. Please don't add one.
*/
static int __init cpufreq_p4_init(void)
{
int ret;
/*
* THERM_CONTROL is architectural for IA32 now, so
* we can rely on the capability checks
*/
if (!x86_match_cpu(cpufreq_p4_id) || !boot_cpu_has(X86_FEATURE_ACPI))
return -ENODEV;
ret = cpufreq_register_driver(&p4clockmod_driver);
if (!ret)
pr_info("P4/Xeon(TM) CPU On-Demand Clock Modulation available\n");
return ret;
}
static void __exit cpufreq_p4_exit(void)
{
cpufreq_unregister_driver(&p4clockmod_driver);
}
MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
MODULE_DESCRIPTION("cpufreq driver for Pentium(TM) 4/Xeon(TM)");
MODULE_LICENSE("GPL");
late_initcall(cpufreq_p4_init);
module_exit(cpufreq_p4_exit);