+++ /dev/null
-/* 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;
-
- if (!cpu_online(cpu))
- return 0;
-
- cpus_allowed = current->cpus_allowed;
- set_cpus_allowed(current, cpumask_of_cpu(cpu));
-
- reg = read_safari_cfg();
- ret = get_current_freq(cpu, reg);
-
- set_cpus_allowed(current, cpus_allowed);
-
- return ret;
-}
-
-static void us3_set_cpu_divider_index(unsigned int cpu, unsigned int index)
-{
- unsigned long new_bits, new_freq, reg;
- cpumask_t cpus_allowed;
- struct cpufreq_freqs freqs;
-
- if (!cpu_online(cpu))
- return;
-
- cpus_allowed = current->cpus_allowed;
- set_cpus_allowed(current, cpumask_of_cpu(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;
- 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_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->cpu, 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].index = 0;
- table[0].frequency = clock_tick / 1;
- table[1].index = 1;
- table[1].frequency = clock_tick / 2;
- table[2].index = 2;
- table[2].frequency = clock_tick / 32;
- table[3].index = 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->cpu, 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);
git.samba.org / sfrench / cifs-2.6.git / blobdiff