diff options
Diffstat (limited to 'drivers/cpufreq/vexpress-spc-cpufreq.c')
-rw-r--r-- | drivers/cpufreq/vexpress-spc-cpufreq.c | 584 |
1 files changed, 559 insertions, 25 deletions
diff --git a/drivers/cpufreq/vexpress-spc-cpufreq.c b/drivers/cpufreq/vexpress-spc-cpufreq.c index 53237289e606..83c85d3d67e3 100644 --- a/drivers/cpufreq/vexpress-spc-cpufreq.c +++ b/drivers/cpufreq/vexpress-spc-cpufreq.c @@ -1,61 +1,592 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Versatile Express SPC CPUFreq Interface driver * - * It provides necessary ops to arm_big_little cpufreq driver. + * Copyright (C) 2013 - 2019 ARM Ltd. + * Sudeep Holla <sudeep.holla@arm.com> * - * Copyright (C) 2013 ARM Ltd. - * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed "as is" WITHOUT ANY WARRANTY of any - * kind, whether express or implied; without even the implied warranty - * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. + * Copyright (C) 2013 Linaro. + * Viresh Kumar <viresh.kumar@linaro.org> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/clk.h> #include <linux/cpu.h> #include <linux/cpufreq.h> +#include <linux/cpumask.h> +#include <linux/cpu_cooling.h> +#include <linux/device.h> #include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/pm_opp.h> +#include <linux/slab.h> +#include <linux/topology.h> #include <linux/types.h> -#include "arm_big_little.h" +/* Currently we support only two clusters */ +#define A15_CLUSTER 0 +#define A7_CLUSTER 1 +#define MAX_CLUSTERS 2 + +#ifdef CONFIG_BL_SWITCHER +#include <asm/bL_switcher.h> +static bool bL_switching_enabled; +#define is_bL_switching_enabled() bL_switching_enabled +#define set_switching_enabled(x) (bL_switching_enabled = (x)) +#else +#define is_bL_switching_enabled() false +#define set_switching_enabled(x) do { } while (0) +#define bL_switch_request(...) do { } while (0) +#define bL_switcher_put_enabled() do { } while (0) +#define bL_switcher_get_enabled() do { } while (0) +#endif + +#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq) +#define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq) + +static struct thermal_cooling_device *cdev[MAX_CLUSTERS]; +static struct clk *clk[MAX_CLUSTERS]; +static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1]; +static atomic_t cluster_usage[MAX_CLUSTERS + 1]; + +static unsigned int clk_big_min; /* (Big) clock frequencies */ +static unsigned int clk_little_max; /* Maximum clock frequency (Little) */ + +static DEFINE_PER_CPU(unsigned int, physical_cluster); +static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq); + +static struct mutex cluster_lock[MAX_CLUSTERS]; + +static inline int raw_cpu_to_cluster(int cpu) +{ + return topology_physical_package_id(cpu); +} + +static inline int cpu_to_cluster(int cpu) +{ + return is_bL_switching_enabled() ? + MAX_CLUSTERS : raw_cpu_to_cluster(cpu); +} + +static unsigned int find_cluster_maxfreq(int cluster) +{ + int j; + u32 max_freq = 0, cpu_freq; + + for_each_online_cpu(j) { + cpu_freq = per_cpu(cpu_last_req_freq, j); + + if (cluster == per_cpu(physical_cluster, j) && + max_freq < cpu_freq) + max_freq = cpu_freq; + } + + return max_freq; +} + +static unsigned int clk_get_cpu_rate(unsigned int cpu) +{ + u32 cur_cluster = per_cpu(physical_cluster, cpu); + u32 rate = clk_get_rate(clk[cur_cluster]) / 1000; + + /* For switcher we use virtual A7 clock rates */ + if (is_bL_switching_enabled()) + rate = VIRT_FREQ(cur_cluster, rate); + + return rate; +} + +static unsigned int ve_spc_cpufreq_get_rate(unsigned int cpu) +{ + if (is_bL_switching_enabled()) + return per_cpu(cpu_last_req_freq, cpu); + else + return clk_get_cpu_rate(cpu); +} + +static unsigned int +ve_spc_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate) +{ + u32 new_rate, prev_rate; + int ret; + bool bLs = is_bL_switching_enabled(); + + mutex_lock(&cluster_lock[new_cluster]); + + if (bLs) { + prev_rate = per_cpu(cpu_last_req_freq, cpu); + per_cpu(cpu_last_req_freq, cpu) = rate; + per_cpu(physical_cluster, cpu) = new_cluster; + + new_rate = find_cluster_maxfreq(new_cluster); + new_rate = ACTUAL_FREQ(new_cluster, new_rate); + } else { + new_rate = rate; + } + + ret = clk_set_rate(clk[new_cluster], new_rate * 1000); + if (!ret) { + /* + * FIXME: clk_set_rate hasn't returned an error here however it + * may be that clk_change_rate failed due to hardware or + * firmware issues and wasn't able to report that due to the + * current design of the clk core layer. To work around this + * problem we will read back the clock rate and check it is + * correct. This needs to be removed once clk core is fixed. + */ + if (clk_get_rate(clk[new_cluster]) != new_rate * 1000) + ret = -EIO; + } + + if (WARN_ON(ret)) { + if (bLs) { + per_cpu(cpu_last_req_freq, cpu) = prev_rate; + per_cpu(physical_cluster, cpu) = old_cluster; + } + + mutex_unlock(&cluster_lock[new_cluster]); + + return ret; + } + + mutex_unlock(&cluster_lock[new_cluster]); + + /* Recalc freq for old cluster when switching clusters */ + if (old_cluster != new_cluster) { + /* Switch cluster */ + bL_switch_request(cpu, new_cluster); + + mutex_lock(&cluster_lock[old_cluster]); + + /* Set freq of old cluster if there are cpus left on it */ + new_rate = find_cluster_maxfreq(old_cluster); + new_rate = ACTUAL_FREQ(old_cluster, new_rate); + + if (new_rate && + clk_set_rate(clk[old_cluster], new_rate * 1000)) { + pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n", + __func__, ret, old_cluster); + } + mutex_unlock(&cluster_lock[old_cluster]); + } + + return 0; +} + +/* Set clock frequency */ +static int ve_spc_cpufreq_set_target(struct cpufreq_policy *policy, + unsigned int index) +{ + u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster; + unsigned int freqs_new; + int ret; + + cur_cluster = cpu_to_cluster(cpu); + new_cluster = actual_cluster = per_cpu(physical_cluster, cpu); + + freqs_new = freq_table[cur_cluster][index].frequency; + + if (is_bL_switching_enabled()) { + if (actual_cluster == A15_CLUSTER && freqs_new < clk_big_min) + new_cluster = A7_CLUSTER; + else if (actual_cluster == A7_CLUSTER && + freqs_new > clk_little_max) + new_cluster = A15_CLUSTER; + } + + ret = ve_spc_cpufreq_set_rate(cpu, actual_cluster, new_cluster, + freqs_new); + + if (!ret) { + arch_set_freq_scale(policy->related_cpus, freqs_new, + policy->cpuinfo.max_freq); + } + + return ret; +} + +static inline u32 get_table_count(struct cpufreq_frequency_table *table) +{ + int count; + + for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++) + ; + + return count; +} + +/* get the minimum frequency in the cpufreq_frequency_table */ +static inline u32 get_table_min(struct cpufreq_frequency_table *table) +{ + struct cpufreq_frequency_table *pos; + u32 min_freq = ~0; + + cpufreq_for_each_entry(pos, table) + if (pos->frequency < min_freq) + min_freq = pos->frequency; + return min_freq; +} + +/* get the maximum frequency in the cpufreq_frequency_table */ +static inline u32 get_table_max(struct cpufreq_frequency_table *table) +{ + struct cpufreq_frequency_table *pos; + u32 max_freq = 0; + + cpufreq_for_each_entry(pos, table) + if (pos->frequency > max_freq) + max_freq = pos->frequency; + return max_freq; +} + +static bool search_frequency(struct cpufreq_frequency_table *table, int size, + unsigned int freq) +{ + int count; + + for (count = 0; count < size; count++) { + if (table[count].frequency == freq) + return true; + } + + return false; +} + +static int merge_cluster_tables(void) +{ + int i, j, k = 0, count = 1; + struct cpufreq_frequency_table *table; + + for (i = 0; i < MAX_CLUSTERS; i++) + count += get_table_count(freq_table[i]); + + table = kcalloc(count, sizeof(*table), GFP_KERNEL); + if (!table) + return -ENOMEM; + + freq_table[MAX_CLUSTERS] = table; + + /* Add in reverse order to get freqs in increasing order */ + for (i = MAX_CLUSTERS - 1; i >= 0; i--, count = k) { + for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END; + j++) { + if (i == A15_CLUSTER && + search_frequency(table, count, freq_table[i][j].frequency)) + continue; /* skip duplicates */ + table[k++].frequency = + VIRT_FREQ(i, freq_table[i][j].frequency); + } + } + + table[k].driver_data = k; + table[k].frequency = CPUFREQ_TABLE_END; + + return 0; +} -static int ve_spc_init_opp_table(const struct cpumask *cpumask) +static void _put_cluster_clk_and_freq_table(struct device *cpu_dev, + const struct cpumask *cpumask) { - struct device *cpu_dev = get_cpu_device(cpumask_first(cpumask)); + u32 cluster = raw_cpu_to_cluster(cpu_dev->id); + + if (!freq_table[cluster]) + return; + + clk_put(clk[cluster]); + dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]); +} + +static void put_cluster_clk_and_freq_table(struct device *cpu_dev, + const struct cpumask *cpumask) +{ + u32 cluster = cpu_to_cluster(cpu_dev->id); + int i; + + if (atomic_dec_return(&cluster_usage[cluster])) + return; + + if (cluster < MAX_CLUSTERS) + return _put_cluster_clk_and_freq_table(cpu_dev, cpumask); + + for_each_present_cpu(i) { + struct device *cdev = get_cpu_device(i); + + if (!cdev) + return; + + _put_cluster_clk_and_freq_table(cdev, cpumask); + } + + /* free virtual table */ + kfree(freq_table[cluster]); +} + +static int _get_cluster_clk_and_freq_table(struct device *cpu_dev, + const struct cpumask *cpumask) +{ + u32 cluster = raw_cpu_to_cluster(cpu_dev->id); + int ret; + + if (freq_table[cluster]) + return 0; + /* * platform specific SPC code must initialise the opp table * so just check if the OPP count is non-zero */ - return dev_pm_opp_get_opp_count(cpu_dev) <= 0; + ret = dev_pm_opp_get_opp_count(cpu_dev) <= 0; + if (ret) + goto out; + + ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]); + if (ret) + goto out; + + clk[cluster] = clk_get(cpu_dev, NULL); + if (!IS_ERR(clk[cluster])) + return 0; + + dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n", + __func__, cpu_dev->id, cluster); + ret = PTR_ERR(clk[cluster]); + dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]); + +out: + dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__, + cluster); + return ret; } -static int ve_spc_get_transition_latency(struct device *cpu_dev) +static int get_cluster_clk_and_freq_table(struct device *cpu_dev, + const struct cpumask *cpumask) { - return 1000000; /* 1 ms */ + u32 cluster = cpu_to_cluster(cpu_dev->id); + int i, ret; + + if (atomic_inc_return(&cluster_usage[cluster]) != 1) + return 0; + + if (cluster < MAX_CLUSTERS) { + ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask); + if (ret) + atomic_dec(&cluster_usage[cluster]); + return ret; + } + + /* + * Get data for all clusters and fill virtual cluster with a merge of + * both + */ + for_each_present_cpu(i) { + struct device *cdev = get_cpu_device(i); + + if (!cdev) + return -ENODEV; + + ret = _get_cluster_clk_and_freq_table(cdev, cpumask); + if (ret) + goto put_clusters; + } + + ret = merge_cluster_tables(); + if (ret) + goto put_clusters; + + /* Assuming 2 cluster, set clk_big_min and clk_little_max */ + clk_big_min = get_table_min(freq_table[A15_CLUSTER]); + clk_little_max = VIRT_FREQ(A7_CLUSTER, + get_table_max(freq_table[A7_CLUSTER])); + + return 0; + +put_clusters: + for_each_present_cpu(i) { + struct device *cdev = get_cpu_device(i); + + if (!cdev) + return -ENODEV; + + _put_cluster_clk_and_freq_table(cdev, cpumask); + } + + atomic_dec(&cluster_usage[cluster]); + + return ret; } -static const struct cpufreq_arm_bL_ops ve_spc_cpufreq_ops = { - .name = "vexpress-spc", - .get_transition_latency = ve_spc_get_transition_latency, - .init_opp_table = ve_spc_init_opp_table, +/* Per-CPU initialization */ +static int ve_spc_cpufreq_init(struct cpufreq_policy *policy) +{ + u32 cur_cluster = cpu_to_cluster(policy->cpu); + struct device *cpu_dev; + int ret; + + cpu_dev = get_cpu_device(policy->cpu); + if (!cpu_dev) { + pr_err("%s: failed to get cpu%d device\n", __func__, + policy->cpu); + return -ENODEV; + } + + if (cur_cluster < MAX_CLUSTERS) { + int cpu; + + dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus); + + for_each_cpu(cpu, policy->cpus) + per_cpu(physical_cluster, cpu) = cur_cluster; + } else { + /* Assumption: during init, we are always running on A15 */ + per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER; + } + + ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus); + if (ret) + return ret; + + policy->freq_table = freq_table[cur_cluster]; + policy->cpuinfo.transition_latency = 1000000; /* 1 ms */ + + dev_pm_opp_of_register_em(policy->cpus); + + if (is_bL_switching_enabled()) + per_cpu(cpu_last_req_freq, policy->cpu) = + clk_get_cpu_rate(policy->cpu); + + dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu); + return 0; +} + +static int ve_spc_cpufreq_exit(struct cpufreq_policy *policy) +{ + struct device *cpu_dev; + int cur_cluster = cpu_to_cluster(policy->cpu); + + if (cur_cluster < MAX_CLUSTERS) { + cpufreq_cooling_unregister(cdev[cur_cluster]); + cdev[cur_cluster] = NULL; + } + + cpu_dev = get_cpu_device(policy->cpu); + if (!cpu_dev) { + pr_err("%s: failed to get cpu%d device\n", __func__, + policy->cpu); + return -ENODEV; + } + + put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus); + return 0; +} + +static void ve_spc_cpufreq_ready(struct cpufreq_policy *policy) +{ + int cur_cluster = cpu_to_cluster(policy->cpu); + + /* Do not register a cpu_cooling device if we are in IKS mode */ + if (cur_cluster >= MAX_CLUSTERS) + return; + + cdev[cur_cluster] = of_cpufreq_cooling_register(policy); +} + +static struct cpufreq_driver ve_spc_cpufreq_driver = { + .name = "vexpress-spc", + .flags = CPUFREQ_STICKY | + CPUFREQ_HAVE_GOVERNOR_PER_POLICY | + CPUFREQ_NEED_INITIAL_FREQ_CHECK, + .verify = cpufreq_generic_frequency_table_verify, + .target_index = ve_spc_cpufreq_set_target, + .get = ve_spc_cpufreq_get_rate, + .init = ve_spc_cpufreq_init, + .exit = ve_spc_cpufreq_exit, + .ready = ve_spc_cpufreq_ready, + .attr = cpufreq_generic_attr, }; +#ifdef CONFIG_BL_SWITCHER +static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb, + unsigned long action, void *_arg) +{ + pr_debug("%s: action: %ld\n", __func__, action); + + switch (action) { + case BL_NOTIFY_PRE_ENABLE: + case BL_NOTIFY_PRE_DISABLE: + cpufreq_unregister_driver(&ve_spc_cpufreq_driver); + break; + + case BL_NOTIFY_POST_ENABLE: + set_switching_enabled(true); + cpufreq_register_driver(&ve_spc_cpufreq_driver); + break; + + case BL_NOTIFY_POST_DISABLE: + set_switching_enabled(false); + cpufreq_register_driver(&ve_spc_cpufreq_driver); + break; + + default: + return NOTIFY_DONE; + } + + return NOTIFY_OK; +} + +static struct notifier_block bL_switcher_notifier = { + .notifier_call = bL_cpufreq_switcher_notifier, +}; + +static int __bLs_register_notifier(void) +{ + return bL_switcher_register_notifier(&bL_switcher_notifier); +} + +static int __bLs_unregister_notifier(void) +{ + return bL_switcher_unregister_notifier(&bL_switcher_notifier); +} +#else +static int __bLs_register_notifier(void) { return 0; } +static int __bLs_unregister_notifier(void) { return 0; } +#endif + static int ve_spc_cpufreq_probe(struct platform_device *pdev) { - return bL_cpufreq_register(&ve_spc_cpufreq_ops); + int ret, i; + + set_switching_enabled(bL_switcher_get_enabled()); + + for (i = 0; i < MAX_CLUSTERS; i++) + mutex_init(&cluster_lock[i]); + + ret = cpufreq_register_driver(&ve_spc_cpufreq_driver); + if (ret) { + pr_info("%s: Failed registering platform driver: %s, err: %d\n", + __func__, ve_spc_cpufreq_driver.name, ret); + } else { + ret = __bLs_register_notifier(); + if (ret) + cpufreq_unregister_driver(&ve_spc_cpufreq_driver); + else + pr_info("%s: Registered platform driver: %s\n", + __func__, ve_spc_cpufreq_driver.name); + } + + bL_switcher_put_enabled(); + return ret; } static int ve_spc_cpufreq_remove(struct platform_device *pdev) { - bL_cpufreq_unregister(&ve_spc_cpufreq_ops); + bL_switcher_get_enabled(); + __bLs_unregister_notifier(); + cpufreq_unregister_driver(&ve_spc_cpufreq_driver); + bL_switcher_put_enabled(); + pr_info("%s: Un-registered platform driver: %s\n", __func__, + ve_spc_cpufreq_driver.name); return 0; } @@ -68,4 +599,7 @@ static struct platform_driver ve_spc_cpufreq_platdrv = { }; module_platform_driver(ve_spc_cpufreq_platdrv); -MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); +MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); +MODULE_DESCRIPTION("Vexpress SPC ARM big LITTLE cpufreq driver"); +MODULE_LICENSE("GPL v2"); |