Commit a67f5a41 authored by David S. Miller's avatar David S. Miller

[SPARC64]: Add UltraSPARC-III cpu frequency driver.

parent eb1b97b1
......@@ -139,6 +139,39 @@ config NR_CPUS
depends on SMP
default "64"
config CPU_FREQ
bool "CPU Frequency scaling"
help
Clock scaling allows you to change the clock speed of CPUs on the
fly. Currently there is only a sparc64 driver for UltraSPARC-III
processors.
For details, take a look at linux/Documentation/cpufreq.
If in doubt, say N.
config CPU_FREQ_PROC_INTF
bool "/proc/cpufreq interface (DEPRECATED)"
depends on CPU_FREQ && PROC_FS
help
This enables the /proc/cpufreq interface for controlling
CPUFreq. Please note that it is recommended to use the sysfs
interface instead (which is built automatically).
For details, take a look at linux/Documentation/cpufreq.
If in doubt, say N.
config US3_FREQ
tristate "UltraSPARC-III CPU Frequency driver"
depends on CPU_FREQ
help
This adds the CPUFreq driver for UltraSPARC-III processors.
For details, take a look at linux/Documentation/cpufreq.
If in doubt, say N.
# Identify this as a Sparc64 build
config SPARC64
bool
......
......@@ -21,6 +21,7 @@ obj-$(CONFIG_SPARC32_COMPAT) += sys32.o sys_sparc32.o signal32.o ioctl32.o
obj-$(CONFIG_BINFMT_ELF32) += binfmt_elf32.o
obj-$(CONFIG_BINFMT_AOUT32) += binfmt_aout32.o
obj-$(CONFIG_MODULES) += module.o
obj-$(CONFIG_US3_FREQ) += us3_cpufreq.o
ifdef CONFIG_SUNOS_EMUL
obj-y += sys_sunos32.o sunos_ioctl32.o
......
/* us3_cpufreq.c: UltraSPARC-III cpu frequency support
*
* Copyright (C) 2003 David S. Miller (davem@redhat.com)
*
* Many thanks to Dominik Brodowski for fixing up the cpufreq
* infrastructure in order to make this driver easier to implement.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/cpufreq.h>
#include <linux/threads.h>
#include <linux/slab.h>
#include <linux/init.h>
static struct cpufreq_driver *cpufreq_us3_driver;
/* Index by [(CPU * 4) + INDEX] (first three indices are
* actual us3 divisor entries, last is for CPUFREQ_TABLE_END)
*/
static struct cpufreq_frequency_table *us3_freq_table;
/* UltraSPARC-III has three dividers: 1, 2, and 32. These are controlled
* in the Safari config register.
*/
#define SAFARI_CFG_DIV_1 0x0000000000000000UL
#define SAFARI_CFG_DIV_2 0x0000000040000000UL
#define SAFARI_CFG_DIV_32 0x0000000080000000UL
#define SAFARI_CFG_DIV_MASK 0x00000000C0000000UL
static unsigned long read_safari_cfg(void)
{
unsigned long ret;
__asm__ __volatile__("ldxa [%%g0] %1, %0"
: "=&r" (ret)
: "i" (ASI_SAFARI_CONFIG));
return ret;
}
static void write_safari_cfg(unsigned long val)
{
__asm__ __volatile__("stxa %0, [%%g0] %1\n\t"
"membar #Sync"
: /* no outputs */
: "r" (val), "i" (ASI_SAFARI_CONFIG)
: "memory");
}
#ifndef CONFIG_SMP
extern unsigned long up_clock_tick;
#endif
static __inline__ unsigned long get_clock_tick(unsigned int cpu)
{
#ifdef CONFIG_SMP
return cpu_data[cpu].clock_tick;
#else
return up_clock_tick;
#endif
}
static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
{
unsigned long clock_tick = get_clock_tick(cpu);
unsigned long ret;
switch (safari_cfg & SAFARI_CFG_DIV_MASK) {
case SAFARI_CFG_DIV_1:
ret = clock_tick / 1;
break;
case SAFARI_CFG_DIV_2:
ret = clock_tick / 2;
break;
case SAFARI_CFG_DIV_32:
ret = clock_tick / 32;
break;
default:
BUG();
};
return ret;
}
static void us3_set_cpu_divider_index(unsigned int cpu, unsigned int index)
{
unsigned long new_bits, new_freq, reg, cpus_allowed;
struct cpufreq_freqs freqs;
if (!cpu_online(cpu))
return;
cpus_allowed = current->cpus_allowed;
set_cpus_allowed(current, (1UL << cpu));
new_freq = get_clock_tick(cpu);
switch (index) {
case 0:
new_bits = SAFARI_CFG_DIV_1;
new_freq /= 1;
break;
case 1:
new_bits = SAFARI_CFG_DIV_2;
new_freq /= 2;
break;
case 2:
new_bits = SAFARI_CFG_DIV_32;
new_freq /= 32;
break;
default:
BUG();
};
reg = read_safari_cfg();
freqs.old = get_current_freq(cpu, reg);
freqs.new = new_freq;
freqs.cpu = cpu;
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
reg &= ~SAFARI_CFG_DIV_MASK;
reg |= new_bits;
write_safari_cfg(reg);
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
set_cpus_allowed(current, cpus_allowed);
}
static int us3_setpolicy(struct cpufreq_policy *policy)
{
unsigned int new_index = 0;
if (cpufreq_frequency_table_setpolicy(policy,
&us3_freq_table[(policy->cpu * 4) + 0],
&new_index))
return -EINVAL;
us3_set_cpu_divider_index(policy->cpu, new_index);
return 0;
}
static int us3_verify(struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy,
&us3_freq_table[(policy->cpu * 4) + 0]);
}
#ifndef CONFIG_SMP
extern unsigned long up_clock_tick;
#endif
static void __init us3_init_freq_table(unsigned int cpu)
{
unsigned long clock_tick = get_clock_tick(cpu);
us3_freq_table[(cpu * 4) + 0].index = 0;
us3_freq_table[(cpu * 4) + 0].frequency = clock_tick / 1;
us3_freq_table[(cpu * 4) + 1].index = 1;
us3_freq_table[(cpu * 4) + 1].frequency = clock_tick / 2;
us3_freq_table[(cpu * 4) + 2].index = 2;
us3_freq_table[(cpu * 4) + 2].frequency = clock_tick / 32;
us3_freq_table[(cpu * 4) + 3].index = 0;
us3_freq_table[(cpu * 4) + 3].frequency = CPUFREQ_TABLE_END;
}
static int __init us3freq_init(void)
{
struct cpufreq_driver *driver;
unsigned long manuf, impl, ver;
int i, ret;
__asm__("rdpr %%ver, %0" : "=r" (ver));
manuf = ((ver >> 48) & 0xffff);
impl = ((ver >> 32) & 0xffff);
/* XXX Maybe accept cheetah+ too? */
if (manuf == 0x3e && impl == 0x14) {
driver = kmalloc(sizeof(struct cpufreq_driver) +
(NR_CPUS * sizeof(struct cpufreq_policy)),
GFP_KERNEL);
if (!driver)
return -ENOMEM;
us3_freq_table = kmalloc(
(NR_CPUS * 4 * sizeof(struct cpufreq_frequency_table)),
GFP_KERNEL);
if (!us3_freq_table) {
kfree(driver);
return -ENOMEM;
}
driver->policy = (struct cpufreq_policy *) (driver + 1);
driver->verify = us3_verify;
driver->setpolicy = us3_setpolicy;
for (i = 0; i < NR_CPUS; i++) {
driver->policy[i].cpu = i;
us3_init_freq_table(i);
ret = cpufreq_frequency_table_cpuinfo(&driver->policy[i],
&us3_freq_table[(i * 4) + 0]);
if (ret) {
kfree(driver);
kfree(us3_freq_table);
us3_freq_table = NULL;
return ret;
}
driver->policy[i].policy = CPUFREQ_POLICY_PERFORMANCE;
us3_set_cpu_divider_index(i, 0);
}
cpufreq_us3_driver = driver;
ret = cpufreq_register_driver(driver);
if (ret) {
kfree(driver);
cpufreq_us3_driver = NULL;
kfree(us3_freq_table);
us3_freq_table = NULL;
return ret;
}
return 0;
}
return -ENODEV;
}
static void __exit us3freq_exit(void)
{
int i;
if (cpufreq_us3_driver) {
for (i = 0; i < NR_CPUS; i++)
us3_set_cpu_divider_index(i, 0);
cpufreq_unregister_driver(cpufreq_us3_driver);
kfree(cpufreq_us3_driver);
cpufreq_us3_driver = NULL;
kfree(us3_freq_table);
us3_freq_table = NULL;
}
}
MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III");
MODULE_LICENSE("GPL");
module_init(us3freq_init);
module_exit(us3freq_exit);
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