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![Markus Elfring](/assets/img/avatar_default.png)
The kfree() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
175 lines
4.2 KiB
C
175 lines
4.2 KiB
C
/*
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* CPPC (Collaborative Processor Performance Control) driver for
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* interfacing with the CPUfreq layer and governors. See
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* cppc_acpi.c for CPPC specific methods.
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*
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* (C) Copyright 2014, 2015 Linaro Ltd.
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* Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; version 2
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* of the License.
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*/
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#define pr_fmt(fmt) "CPPC Cpufreq:" fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/cpu.h>
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#include <linux/cpufreq.h>
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#include <linux/vmalloc.h>
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#include <acpi/cppc_acpi.h>
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/*
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* These structs contain information parsed from per CPU
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* ACPI _CPC structures.
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* e.g. For each CPU the highest, lowest supported
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* performance capabilities, desired performance level
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* requested etc.
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*/
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static struct cpudata **all_cpu_data;
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static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
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unsigned int target_freq,
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unsigned int relation)
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{
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struct cpudata *cpu;
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struct cpufreq_freqs freqs;
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int ret = 0;
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cpu = all_cpu_data[policy->cpu];
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cpu->perf_ctrls.desired_perf = target_freq;
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freqs.old = policy->cur;
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freqs.new = target_freq;
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cpufreq_freq_transition_begin(policy, &freqs);
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ret = cppc_set_perf(cpu->cpu, &cpu->perf_ctrls);
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cpufreq_freq_transition_end(policy, &freqs, ret != 0);
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if (ret)
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pr_debug("Failed to set target on CPU:%d. ret:%d\n",
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cpu->cpu, ret);
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return ret;
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}
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static int cppc_verify_policy(struct cpufreq_policy *policy)
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{
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cpufreq_verify_within_cpu_limits(policy);
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return 0;
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}
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static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy)
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{
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int cpu_num = policy->cpu;
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struct cpudata *cpu = all_cpu_data[cpu_num];
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int ret;
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cpu->perf_ctrls.desired_perf = cpu->perf_caps.lowest_perf;
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ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
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if (ret)
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pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
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cpu->perf_caps.lowest_perf, cpu_num, ret);
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}
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static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
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{
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struct cpudata *cpu;
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unsigned int cpu_num = policy->cpu;
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int ret = 0;
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cpu = all_cpu_data[policy->cpu];
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cpu->cpu = cpu_num;
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ret = cppc_get_perf_caps(policy->cpu, &cpu->perf_caps);
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if (ret) {
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pr_debug("Err reading CPU%d perf capabilities. ret:%d\n",
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cpu_num, ret);
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return ret;
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}
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policy->min = cpu->perf_caps.lowest_perf;
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policy->max = cpu->perf_caps.highest_perf;
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policy->cpuinfo.min_freq = policy->min;
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policy->cpuinfo.max_freq = policy->max;
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if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
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cpumask_copy(policy->cpus, cpu->shared_cpu_map);
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else {
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/* Support only SW_ANY for now. */
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pr_debug("Unsupported CPU co-ord type\n");
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return -EFAULT;
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}
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cpumask_set_cpu(policy->cpu, policy->cpus);
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cpu->cur_policy = policy;
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/* Set policy->cur to max now. The governors will adjust later. */
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policy->cur = cpu->perf_ctrls.desired_perf = cpu->perf_caps.highest_perf;
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ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
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if (ret)
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pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
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cpu->perf_caps.highest_perf, cpu_num, ret);
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return ret;
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}
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static struct cpufreq_driver cppc_cpufreq_driver = {
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.flags = CPUFREQ_CONST_LOOPS,
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.verify = cppc_verify_policy,
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.target = cppc_cpufreq_set_target,
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.init = cppc_cpufreq_cpu_init,
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.stop_cpu = cppc_cpufreq_stop_cpu,
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.name = "cppc_cpufreq",
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};
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static int __init cppc_cpufreq_init(void)
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{
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int i, ret = 0;
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struct cpudata *cpu;
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if (acpi_disabled)
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return -ENODEV;
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all_cpu_data = kzalloc(sizeof(void *) * num_possible_cpus(), GFP_KERNEL);
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if (!all_cpu_data)
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return -ENOMEM;
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for_each_possible_cpu(i) {
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all_cpu_data[i] = kzalloc(sizeof(struct cpudata), GFP_KERNEL);
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if (!all_cpu_data[i])
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goto out;
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cpu = all_cpu_data[i];
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if (!zalloc_cpumask_var(&cpu->shared_cpu_map, GFP_KERNEL))
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goto out;
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}
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ret = acpi_get_psd_map(all_cpu_data);
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if (ret) {
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pr_debug("Error parsing PSD data. Aborting cpufreq registration.\n");
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goto out;
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}
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ret = cpufreq_register_driver(&cppc_cpufreq_driver);
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if (ret)
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goto out;
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return ret;
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out:
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for_each_possible_cpu(i)
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kfree(all_cpu_data[i]);
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kfree(all_cpu_data);
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return -ENODEV;
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}
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late_initcall(cppc_cpufreq_init);
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