cpufreq: arm_big_little: add in-kernel switching (IKS) support
This patch adds IKS (In Kernel Switcher) support to cpufreq driver. This creates a combined freq table for A7-A15 CPU pairs. A7 frequencies are virtualized and scaled down to half the actual frequencies to approximate a linear scale across the combined A7+A15 range. When the requested frequency change crosses the A7-A15 boundary a cluster switch is invoked. Based on earlier work from Sudeep KarkadaNagesha. Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Viresh Kumar
Rafael J. Wysocki
parent
9e941b6f42
commit
e79a23c5b9
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@ -24,27 +24,165 @@
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#include <linux/cpufreq.h>
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#include <linux/cpumask.h>
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#include <linux/export.h>
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#include <linux/mutex.h>
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#include <linux/of_platform.h>
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#include <linux/pm_opp.h>
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#include <linux/slab.h>
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#include <linux/topology.h>
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#include <linux/types.h>
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#include <asm/bL_switcher.h>
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#include "arm_big_little.h"
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/* Currently we support only two clusters */
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#define A15_CLUSTER 0
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#define A7_CLUSTER 1
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#define MAX_CLUSTERS 2
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#ifdef CONFIG_BL_SWITCHER
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#define is_bL_switching_enabled() true
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#else
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#define is_bL_switching_enabled() false
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#endif
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#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
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#define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
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static struct cpufreq_arm_bL_ops *arm_bL_ops;
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static struct clk *clk[MAX_CLUSTERS];
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static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS];
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static atomic_t cluster_usage[MAX_CLUSTERS] = {ATOMIC_INIT(0), ATOMIC_INIT(0)};
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static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
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static atomic_t cluster_usage[MAX_CLUSTERS + 1];
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static unsigned int bL_cpufreq_get(unsigned int cpu)
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static unsigned int clk_big_min; /* (Big) clock frequencies */
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static unsigned int clk_little_max; /* Maximum clock frequency (Little) */
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static DEFINE_PER_CPU(unsigned int, physical_cluster);
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static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
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static struct mutex cluster_lock[MAX_CLUSTERS];
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static inline int raw_cpu_to_cluster(int cpu)
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{
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u32 cur_cluster = cpu_to_cluster(cpu);
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return topology_physical_package_id(cpu);
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}
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return clk_get_rate(clk[cur_cluster]) / 1000;
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static inline int cpu_to_cluster(int cpu)
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{
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return is_bL_switching_enabled() ?
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MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
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}
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static unsigned int find_cluster_maxfreq(int cluster)
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{
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int j;
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u32 max_freq = 0, cpu_freq;
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for_each_online_cpu(j) {
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cpu_freq = per_cpu(cpu_last_req_freq, j);
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if ((cluster == per_cpu(physical_cluster, j)) &&
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(max_freq < cpu_freq))
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max_freq = cpu_freq;
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}
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pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
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max_freq);
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return max_freq;
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}
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static unsigned int clk_get_cpu_rate(unsigned int cpu)
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{
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u32 cur_cluster = per_cpu(physical_cluster, cpu);
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u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
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/* For switcher we use virtual A7 clock rates */
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if (is_bL_switching_enabled())
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rate = VIRT_FREQ(cur_cluster, rate);
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pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
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cur_cluster, rate);
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return rate;
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}
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static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
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{
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if (is_bL_switching_enabled()) {
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pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
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cpu));
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return per_cpu(cpu_last_req_freq, cpu);
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} else {
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return clk_get_cpu_rate(cpu);
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}
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}
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static unsigned int
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bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
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{
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u32 new_rate, prev_rate;
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int ret;
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bool bLs = is_bL_switching_enabled();
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mutex_lock(&cluster_lock[new_cluster]);
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if (bLs) {
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prev_rate = per_cpu(cpu_last_req_freq, cpu);
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per_cpu(cpu_last_req_freq, cpu) = rate;
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per_cpu(physical_cluster, cpu) = new_cluster;
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new_rate = find_cluster_maxfreq(new_cluster);
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new_rate = ACTUAL_FREQ(new_cluster, new_rate);
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} else {
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new_rate = rate;
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}
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pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
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__func__, cpu, old_cluster, new_cluster, new_rate);
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ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
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if (WARN_ON(ret)) {
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pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
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new_cluster);
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if (bLs) {
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per_cpu(cpu_last_req_freq, cpu) = prev_rate;
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per_cpu(physical_cluster, cpu) = old_cluster;
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}
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mutex_unlock(&cluster_lock[new_cluster]);
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return ret;
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}
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mutex_unlock(&cluster_lock[new_cluster]);
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/* Recalc freq for old cluster when switching clusters */
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if (old_cluster != new_cluster) {
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pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
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__func__, cpu, old_cluster, new_cluster);
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/* Switch cluster */
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bL_switch_request(cpu, new_cluster);
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mutex_lock(&cluster_lock[old_cluster]);
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/* Set freq of old cluster if there are cpus left on it */
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new_rate = find_cluster_maxfreq(old_cluster);
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new_rate = ACTUAL_FREQ(old_cluster, new_rate);
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if (new_rate) {
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pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
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__func__, old_cluster, new_rate);
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if (clk_set_rate(clk[old_cluster], new_rate * 1000))
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pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
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__func__, ret, old_cluster);
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}
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mutex_unlock(&cluster_lock[old_cluster]);
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}
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return 0;
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}
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/* Set clock frequency */
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@ -52,63 +190,164 @@ static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
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unsigned int index)
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{
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struct cpufreq_freqs freqs;
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u32 cpu = policy->cpu, cur_cluster;
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u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
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int ret = 0;
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cur_cluster = cpu_to_cluster(policy->cpu);
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cur_cluster = cpu_to_cluster(cpu);
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new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
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freqs.old = bL_cpufreq_get(policy->cpu);
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freqs.old = bL_cpufreq_get_rate(cpu);
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freqs.new = freq_table[cur_cluster][index].frequency;
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pr_debug("%s: cpu: %d, cluster: %d, oldfreq: %d, target freq: %d, new freq: %d\n",
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__func__, cpu, cur_cluster, freqs.old, freqs.new,
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freqs.new);
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if (is_bL_switching_enabled()) {
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if ((actual_cluster == A15_CLUSTER) &&
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(freqs.new < clk_big_min)) {
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new_cluster = A7_CLUSTER;
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} else if ((actual_cluster == A7_CLUSTER) &&
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(freqs.new > clk_little_max)) {
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new_cluster = A15_CLUSTER;
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}
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}
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cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
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ret = clk_set_rate(clk[cur_cluster], freqs.new * 1000);
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if (ret) {
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pr_err("clk_set_rate failed: %d\n", ret);
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ret = bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs.new);
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if (ret)
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freqs.new = freqs.old;
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}
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cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
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return ret;
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}
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static inline u32 get_table_count(struct cpufreq_frequency_table *table)
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{
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int count;
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for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
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;
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return count;
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}
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/* get the minimum frequency in the cpufreq_frequency_table */
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static inline u32 get_table_min(struct cpufreq_frequency_table *table)
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{
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int i;
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uint32_t min_freq = ~0;
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for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++)
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if (table[i].frequency < min_freq)
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min_freq = table[i].frequency;
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return min_freq;
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}
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/* get the maximum frequency in the cpufreq_frequency_table */
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static inline u32 get_table_max(struct cpufreq_frequency_table *table)
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{
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int i;
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uint32_t max_freq = 0;
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for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++)
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if (table[i].frequency > max_freq)
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max_freq = table[i].frequency;
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return max_freq;
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}
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static int merge_cluster_tables(void)
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{
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int i, j, k = 0, count = 1;
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struct cpufreq_frequency_table *table;
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for (i = 0; i < MAX_CLUSTERS; i++)
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count += get_table_count(freq_table[i]);
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table = kzalloc(sizeof(*table) * count, GFP_KERNEL);
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if (!table)
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return -ENOMEM;
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freq_table[MAX_CLUSTERS] = table;
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/* Add in reverse order to get freqs in increasing order */
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for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
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for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
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j++) {
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table[k].frequency = VIRT_FREQ(i,
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freq_table[i][j].frequency);
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pr_debug("%s: index: %d, freq: %d\n", __func__, k,
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table[k].frequency);
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k++;
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}
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}
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table[k].driver_data = k;
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table[k].frequency = CPUFREQ_TABLE_END;
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pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
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return 0;
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}
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static void _put_cluster_clk_and_freq_table(struct device *cpu_dev)
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{
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u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
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if (!freq_table[cluster])
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return;
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clk_put(clk[cluster]);
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dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
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dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
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}
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static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
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{
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u32 cluster = cpu_to_cluster(cpu_dev->id);
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int i;
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if (!atomic_dec_return(&cluster_usage[cluster])) {
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clk_put(clk[cluster]);
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dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
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dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
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if (atomic_dec_return(&cluster_usage[cluster]))
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return;
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if (cluster < MAX_CLUSTERS)
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return _put_cluster_clk_and_freq_table(cpu_dev);
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for_each_present_cpu(i) {
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struct device *cdev = get_cpu_device(i);
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if (!cdev) {
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pr_err("%s: failed to get cpu%d device\n", __func__, i);
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return;
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}
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_put_cluster_clk_and_freq_table(cdev);
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}
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/* free virtual table */
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kfree(freq_table[cluster]);
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}
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static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
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static int _get_cluster_clk_and_freq_table(struct device *cpu_dev)
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{
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u32 cluster = cpu_to_cluster(cpu_dev->id);
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u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
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char name[14] = "cpu-cluster.";
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int ret;
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if (atomic_inc_return(&cluster_usage[cluster]) != 1)
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if (freq_table[cluster])
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return 0;
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ret = arm_bL_ops->init_opp_table(cpu_dev);
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if (ret) {
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dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
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__func__, cpu_dev->id, ret);
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goto atomic_dec;
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goto out;
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}
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ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
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if (ret) {
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dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
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__func__, cpu_dev->id, ret);
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goto atomic_dec;
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goto out;
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}
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name[12] = cluster + '0';
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@ -125,13 +364,72 @@ static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
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ret = PTR_ERR(clk[cluster]);
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dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
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atomic_dec:
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atomic_dec(&cluster_usage[cluster]);
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out:
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dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
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cluster);
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return ret;
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}
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static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
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{
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u32 cluster = cpu_to_cluster(cpu_dev->id);
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int i, ret;
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if (atomic_inc_return(&cluster_usage[cluster]) != 1)
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return 0;
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if (cluster < MAX_CLUSTERS) {
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ret = _get_cluster_clk_and_freq_table(cpu_dev);
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if (ret)
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atomic_dec(&cluster_usage[cluster]);
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return ret;
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}
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/*
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* Get data for all clusters and fill virtual cluster with a merge of
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* both
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*/
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for_each_present_cpu(i) {
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struct device *cdev = get_cpu_device(i);
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if (!cdev) {
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pr_err("%s: failed to get cpu%d device\n", __func__, i);
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return -ENODEV;
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}
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ret = _get_cluster_clk_and_freq_table(cdev);
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if (ret)
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goto put_clusters;
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}
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ret = merge_cluster_tables();
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if (ret)
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goto put_clusters;
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/* Assuming 2 cluster, set clk_big_min and clk_little_max */
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clk_big_min = get_table_min(freq_table[0]);
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clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
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pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
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__func__, cluster, clk_big_min, clk_little_max);
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return 0;
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put_clusters:
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for_each_present_cpu(i) {
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struct device *cdev = get_cpu_device(i);
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if (!cdev) {
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pr_err("%s: failed to get cpu%d device\n", __func__, i);
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return -ENODEV;
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}
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_put_cluster_clk_and_freq_table(cdev);
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}
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atomic_dec(&cluster_usage[cluster]);
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return ret;
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}
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/* Per-CPU initialization */
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static int bL_cpufreq_init(struct cpufreq_policy *policy)
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{
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@ -158,13 +456,23 @@ static int bL_cpufreq_init(struct cpufreq_policy *policy)
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return ret;
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}
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if (cur_cluster < MAX_CLUSTERS) {
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cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
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per_cpu(physical_cluster, policy->cpu) = cur_cluster;
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} else {
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/* Assumption: during init, we are always running on A15 */
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per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
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}
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if (arm_bL_ops->get_transition_latency)
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policy->cpuinfo.transition_latency =
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arm_bL_ops->get_transition_latency(cpu_dev);
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else
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policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
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cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
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if (is_bL_switching_enabled())
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per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
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dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
|
||||
return 0;
|
||||
|
|
@ -194,7 +502,7 @@ static struct cpufreq_driver bL_cpufreq_driver = {
|
|||
CPUFREQ_HAVE_GOVERNOR_PER_POLICY,
|
||||
.verify = cpufreq_generic_frequency_table_verify,
|
||||
.target_index = bL_cpufreq_set_target,
|
||||
.get = bL_cpufreq_get,
|
||||
.get = bL_cpufreq_get_rate,
|
||||
.init = bL_cpufreq_init,
|
||||
.exit = bL_cpufreq_exit,
|
||||
.attr = cpufreq_generic_attr,
|
||||
|
|
@ -202,7 +510,7 @@ static struct cpufreq_driver bL_cpufreq_driver = {
|
|||
|
||||
int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
|
||||
{
|
||||
int ret;
|
||||
int ret, i;
|
||||
|
||||
if (arm_bL_ops) {
|
||||
pr_debug("%s: Already registered: %s, exiting\n", __func__,
|
||||
|
|
@ -217,6 +525,9 @@ int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
|
|||
|
||||
arm_bL_ops = ops;
|
||||
|
||||
for (i = 0; i < MAX_CLUSTERS; i++)
|
||||
mutex_init(&cluster_lock[i]);
|
||||
|
||||
ret = cpufreq_register_driver(&bL_cpufreq_driver);
|
||||
if (ret) {
|
||||
pr_info("%s: Failed registering platform driver: %s, err: %d\n",
|
||||
|
|
|
|||
|
|
@ -34,11 +34,6 @@ struct cpufreq_arm_bL_ops {
|
|||
int (*init_opp_table)(struct device *cpu_dev);
|
||||
};
|
||||
|
||||
static inline int cpu_to_cluster(int cpu)
|
||||
{
|
||||
return topology_physical_package_id(cpu);
|
||||
}
|
||||
|
||||
int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops);
|
||||
void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops);
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue