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dcfce7c2ce
There is no point allocating the cpufreq driver dynamically and add so much complexity in the driver. Do what is done for other cpufreq drivers and statically allocate the cpufreq driver. Reported-by: Markus Elfring <Markus.Elfring@web.de> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Rafael J. Wysocki <rafael@kernel.org>
201 lines
4.5 KiB
C
201 lines
4.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* us3_cpufreq.c: UltraSPARC-III cpu frequency support
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*
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* Copyright (C) 2003 David S. Miller (davem@redhat.com)
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*
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* Many thanks to Dominik Brodowski for fixing up the cpufreq
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* infrastructure in order to make this driver easier to implement.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/smp.h>
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#include <linux/cpufreq.h>
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#include <linux/threads.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <asm/head.h>
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#include <asm/timer.h>
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struct us3_freq_percpu_info {
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struct cpufreq_frequency_table table[4];
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};
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/* Indexed by cpu number. */
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static struct us3_freq_percpu_info *us3_freq_table;
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/* UltraSPARC-III has three dividers: 1, 2, and 32. These are controlled
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* in the Safari config register.
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*/
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#define SAFARI_CFG_DIV_1 0x0000000000000000UL
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#define SAFARI_CFG_DIV_2 0x0000000040000000UL
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#define SAFARI_CFG_DIV_32 0x0000000080000000UL
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#define SAFARI_CFG_DIV_MASK 0x00000000C0000000UL
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static void read_safari_cfg(void *arg)
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{
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unsigned long ret, *val = arg;
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__asm__ __volatile__("ldxa [%%g0] %1, %0"
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: "=&r" (ret)
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: "i" (ASI_SAFARI_CONFIG));
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*val = ret;
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}
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static void update_safari_cfg(void *arg)
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{
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unsigned long reg, *new_bits = arg;
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read_safari_cfg(®);
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reg &= ~SAFARI_CFG_DIV_MASK;
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reg |= *new_bits;
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__asm__ __volatile__("stxa %0, [%%g0] %1\n\t"
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"membar #Sync"
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: /* no outputs */
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: "r" (reg), "i" (ASI_SAFARI_CONFIG)
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: "memory");
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}
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static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
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{
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unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
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unsigned long ret;
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switch (safari_cfg & SAFARI_CFG_DIV_MASK) {
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case SAFARI_CFG_DIV_1:
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ret = clock_tick / 1;
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break;
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case SAFARI_CFG_DIV_2:
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ret = clock_tick / 2;
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break;
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case SAFARI_CFG_DIV_32:
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ret = clock_tick / 32;
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break;
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default:
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BUG();
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}
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return ret;
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}
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static unsigned int us3_freq_get(unsigned int cpu)
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{
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unsigned long reg;
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if (smp_call_function_single(cpu, read_safari_cfg, ®, 1))
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return 0;
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return get_current_freq(cpu, reg);
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}
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static int us3_freq_target(struct cpufreq_policy *policy, unsigned int index)
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{
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unsigned int cpu = policy->cpu;
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unsigned long new_bits, new_freq;
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new_freq = sparc64_get_clock_tick(cpu) / 1000;
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switch (index) {
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case 0:
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new_bits = SAFARI_CFG_DIV_1;
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new_freq /= 1;
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break;
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case 1:
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new_bits = SAFARI_CFG_DIV_2;
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new_freq /= 2;
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break;
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case 2:
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new_bits = SAFARI_CFG_DIV_32;
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new_freq /= 32;
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break;
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default:
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BUG();
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}
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return smp_call_function_single(cpu, update_safari_cfg, &new_bits, 1);
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}
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static int __init us3_freq_cpu_init(struct cpufreq_policy *policy)
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{
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unsigned int cpu = policy->cpu;
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unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
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struct cpufreq_frequency_table *table =
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&us3_freq_table[cpu].table[0];
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table[0].driver_data = 0;
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table[0].frequency = clock_tick / 1;
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table[1].driver_data = 1;
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table[1].frequency = clock_tick / 2;
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table[2].driver_data = 2;
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table[2].frequency = clock_tick / 32;
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table[3].driver_data = 0;
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table[3].frequency = CPUFREQ_TABLE_END;
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policy->cpuinfo.transition_latency = 0;
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policy->cur = clock_tick;
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policy->freq_table = table;
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return 0;
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}
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static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
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{
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us3_freq_target(policy, 0);
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return 0;
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}
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static struct cpufreq_driver cpufreq_us3_driver = {
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.name = "UltraSPARC-III",
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.init = us3_freq_cpu_init,
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.verify = cpufreq_generic_frequency_table_verify,
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.target_index = us3_freq_target,
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.get = us3_freq_get,
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.exit = us3_freq_cpu_exit,
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};
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static int __init us3_freq_init(void)
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{
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unsigned long manuf, impl, ver;
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int ret;
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if (tlb_type != cheetah && tlb_type != cheetah_plus)
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return -ENODEV;
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__asm__("rdpr %%ver, %0" : "=r" (ver));
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manuf = ((ver >> 48) & 0xffff);
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impl = ((ver >> 32) & 0xffff);
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if (manuf == CHEETAH_MANUF &&
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(impl == CHEETAH_IMPL ||
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impl == CHEETAH_PLUS_IMPL ||
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impl == JAGUAR_IMPL ||
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impl == PANTHER_IMPL)) {
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us3_freq_table = kzalloc(NR_CPUS * sizeof(*us3_freq_table),
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GFP_KERNEL);
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if (!us3_freq_table)
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return -ENOMEM;
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ret = cpufreq_register_driver(&cpufreq_us3_driver);
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if (ret)
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kfree(us3_freq_table);
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return ret;
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}
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return -ENODEV;
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}
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static void __exit us3_freq_exit(void)
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{
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cpufreq_unregister_driver(&cpufreq_us3_driver);
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kfree(us3_freq_table);
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}
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MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
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MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III");
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MODULE_LICENSE("GPL");
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module_init(us3_freq_init);
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module_exit(us3_freq_exit);
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