kernel-ark/drivers/cpufreq/sparc-us3-cpufreq.c
Viresh Kumar 5070158804 cpufreq: rename index as driver_data in cpufreq_frequency_table
The "index" field of struct cpufreq_frequency_table was never an
index and isn't used at all by the cpufreq core.  It only is useful
for cpufreq drivers for their internal purposes.

Many people nowadays blindly set it in ascending order with the
assumption that the core will use it, which is a mistake.

Rename it to "driver_data" as that's what its purpose is. All of its
users are updated accordingly.

[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-04 14:25:59 +02:00

270 lines
6.0 KiB
C

/* 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>
#include <asm/head.h>
#include <asm/timer.h>
static struct cpufreq_driver *cpufreq_us3_driver;
struct us3_freq_percpu_info {
struct cpufreq_frequency_table table[4];
};
/* Indexed by cpu number. */
static struct us3_freq_percpu_info *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");
}
static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
{
unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
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 unsigned int us3_freq_get(unsigned int cpu)
{
cpumask_t cpus_allowed;
unsigned long reg;
unsigned int ret;
cpumask_copy(&cpus_allowed, tsk_cpus_allowed(current));
set_cpus_allowed_ptr(current, cpumask_of(cpu));
reg = read_safari_cfg();
ret = get_current_freq(cpu, reg);
set_cpus_allowed_ptr(current, &cpus_allowed);
return ret;
}
static void us3_set_cpu_divider_index(struct cpufreq_policy *policy,
unsigned int index)
{
unsigned int cpu = policy->cpu;
unsigned long new_bits, new_freq, reg;
cpumask_t cpus_allowed;
struct cpufreq_freqs freqs;
cpumask_copy(&cpus_allowed, tsk_cpus_allowed(current));
set_cpus_allowed_ptr(current, cpumask_of(cpu));
new_freq = sparc64_get_clock_tick(cpu) / 1000;
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;
cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
reg &= ~SAFARI_CFG_DIV_MASK;
reg |= new_bits;
write_safari_cfg(reg);
cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
set_cpus_allowed_ptr(current, &cpus_allowed);
}
static int us3_freq_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
unsigned int new_index = 0;
if (cpufreq_frequency_table_target(policy,
&us3_freq_table[policy->cpu].table[0],
target_freq,
relation,
&new_index))
return -EINVAL;
us3_set_cpu_divider_index(policy, new_index);
return 0;
}
static int us3_freq_verify(struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy,
&us3_freq_table[policy->cpu].table[0]);
}
static int __init us3_freq_cpu_init(struct cpufreq_policy *policy)
{
unsigned int cpu = policy->cpu;
unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
struct cpufreq_frequency_table *table =
&us3_freq_table[cpu].table[0];
table[0].driver_data = 0;
table[0].frequency = clock_tick / 1;
table[1].driver_data = 1;
table[1].frequency = clock_tick / 2;
table[2].driver_data = 2;
table[2].frequency = clock_tick / 32;
table[3].driver_data = 0;
table[3].frequency = CPUFREQ_TABLE_END;
policy->cpuinfo.transition_latency = 0;
policy->cur = clock_tick;
return cpufreq_frequency_table_cpuinfo(policy, table);
}
static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
{
if (cpufreq_us3_driver)
us3_set_cpu_divider_index(policy, 0);
return 0;
}
static int __init us3_freq_init(void)
{
unsigned long manuf, impl, ver;
int ret;
if (tlb_type != cheetah && tlb_type != cheetah_plus)
return -ENODEV;
__asm__("rdpr %%ver, %0" : "=r" (ver));
manuf = ((ver >> 48) & 0xffff);
impl = ((ver >> 32) & 0xffff);
if (manuf == CHEETAH_MANUF &&
(impl == CHEETAH_IMPL ||
impl == CHEETAH_PLUS_IMPL ||
impl == JAGUAR_IMPL ||
impl == PANTHER_IMPL)) {
struct cpufreq_driver *driver;
ret = -ENOMEM;
driver = kzalloc(sizeof(struct cpufreq_driver), GFP_KERNEL);
if (!driver)
goto err_out;
us3_freq_table = kzalloc(
(NR_CPUS * sizeof(struct us3_freq_percpu_info)),
GFP_KERNEL);
if (!us3_freq_table)
goto err_out;
driver->init = us3_freq_cpu_init;
driver->verify = us3_freq_verify;
driver->target = us3_freq_target;
driver->get = us3_freq_get;
driver->exit = us3_freq_cpu_exit;
driver->owner = THIS_MODULE,
strcpy(driver->name, "UltraSPARC-III");
cpufreq_us3_driver = driver;
ret = cpufreq_register_driver(driver);
if (ret)
goto err_out;
return 0;
err_out:
if (driver) {
kfree(driver);
cpufreq_us3_driver = NULL;
}
kfree(us3_freq_table);
us3_freq_table = NULL;
return ret;
}
return -ENODEV;
}
static void __exit us3_freq_exit(void)
{
if (cpufreq_us3_driver) {
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(us3_freq_init);
module_exit(us3_freq_exit);