cpufreq: cpufreq_interactive: avoid NULL point access
[firefly-linux-kernel-4.4.55.git] / drivers / cpufreq / arm_big_little.c
index eaee6e222207a53660b8f9a935dde44cd8ae16d9..c5d256caa664a63731e0cb7db6f5b00e31c750d8 100644 (file)
 #include <linux/cpufreq.h>
 #include <linux/cpumask.h>
 #include <linux/export.h>
+#include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of_platform.h>
-#include <linux/opp.h>
+#include <linux/pm_opp.h>
 #include <linux/slab.h>
 #include <linux/topology.h>
 #include <linux/types.h>
-#include <asm/bL_switcher.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
-bool bL_switching_enabled;
+#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)
+#define ACTUAL_FREQ(cluster, freq)  ((cluster == A7_CLUSTER) ? freq << 1 : freq)
+#define VIRT_FREQ(cluster, freq)    ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
 
 static struct cpufreq_arm_bL_ops *arm_bL_ops;
 static struct clk *clk[MAX_CLUSTERS];
 static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
-static atomic_t cluster_usage[MAX_CLUSTERS + 1] = {ATOMIC_INIT(0),
-       ATOMIC_INIT(0)};
+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) */
@@ -55,6 +68,17 @@ 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;
@@ -79,7 +103,7 @@ 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 A15 clock rates */
+       /* For switcher we use virtual A7 clock rates */
        if (is_bL_switching_enabled())
                rate = VIRT_FREQ(cur_cluster, rate);
 
@@ -125,6 +149,19 @@ bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
                        __func__, cpu, old_cluster, new_cluster, new_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)) {
                pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
                                new_cluster);
@@ -168,61 +205,29 @@ bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
        return 0;
 }
 
-/* Validate policy frequency range */
-static int bL_cpufreq_verify_policy(struct cpufreq_policy *policy)
-{
-       u32 cur_cluster = cpu_to_cluster(policy->cpu);
-
-       return cpufreq_frequency_table_verify(policy, freq_table[cur_cluster]);
-}
-
 /* Set clock frequency */
 static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
-               unsigned int target_freq, unsigned int relation)
+               unsigned int index)
 {
-       struct cpufreq_freqs freqs;
-       u32 cpu = policy->cpu, freq_tab_idx, cur_cluster, new_cluster,
-           actual_cluster;
-       int ret = 0;
+       u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
+       unsigned int freqs_new;
 
        cur_cluster = cpu_to_cluster(cpu);
        new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
 
-       freqs.old = bL_cpufreq_get_rate(cpu);
-
-       /* Determine valid target frequency using freq_table */
-       cpufreq_frequency_table_target(policy, freq_table[cur_cluster],
-                       target_freq, relation, &freq_tab_idx);
-       freqs.new = freq_table[cur_cluster][freq_tab_idx].frequency;
-
-       pr_debug("%s: cpu: %d, cluster: %d, oldfreq: %d, target freq: %d, new freq: %d\n",
-                       __func__, cpu, cur_cluster, freqs.old, target_freq,
-                       freqs.new);
-
-       if (freqs.old == freqs.new)
-               return 0;
+       freqs_new = freq_table[cur_cluster][index].frequency;
 
        if (is_bL_switching_enabled()) {
                if ((actual_cluster == A15_CLUSTER) &&
-                               (freqs.new < clk_big_min)) {
+                               (freqs_new < clk_big_min)) {
                        new_cluster = A7_CLUSTER;
                } else if ((actual_cluster == A7_CLUSTER) &&
-                               (freqs.new > clk_little_max)) {
+                               (freqs_new > clk_little_max)) {
                        new_cluster = A15_CLUSTER;
                }
        }
 
-       cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
-
-       ret = bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs.new);
-       if (ret)
-               return ret;
-
-       policy->cur = freqs.new;
-
-       cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
-
-       return ret;
+       return bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
 }
 
 static inline u32 get_table_count(struct cpufreq_frequency_table *table)
@@ -238,22 +243,22 @@ static inline u32 get_table_count(struct cpufreq_frequency_table *table)
 /* get the minimum frequency in the cpufreq_frequency_table */
 static inline u32 get_table_min(struct cpufreq_frequency_table *table)
 {
-       int i;
+       struct cpufreq_frequency_table *pos;
        uint32_t min_freq = ~0;
-       for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++)
-               if (table[i].frequency < min_freq)
-                       min_freq = table[i].frequency;
+       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)
 {
-       int i;
+       struct cpufreq_frequency_table *pos;
        uint32_t max_freq = 0;
-       for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++)
-               if (table[i].frequency > max_freq)
-                       max_freq = table[i].frequency;
+       cpufreq_for_each_entry(pos, table)
+               if (pos->frequency > max_freq)
+                       max_freq = pos->frequency;
        return max_freq;
 }
 
@@ -283,7 +288,7 @@ static int merge_cluster_tables(void)
                }
        }
 
-       table[k].index = k;
+       table[k].driver_data = k;
        table[k].frequency = CPUFREQ_TABLE_END;
 
        pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
@@ -293,13 +298,16 @@ static int merge_cluster_tables(void)
 
 static void _put_cluster_clk_and_freq_table(struct device *cpu_dev)
 {
-       u32 cluster = cpu_to_cluster(cpu_dev->id);
+       u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
 
-       if (!atomic_dec_return(&cluster_usage[cluster])) {
-               clk_put(clk[cluster]);
-               opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
-               dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
-       }
+       if (!freq_table[cluster])
+               return;
+
+       clk_put(clk[cluster]);
+       dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
+       if (arm_bL_ops->free_opp_table)
+               arm_bL_ops->free_opp_table(cpu_dev);
+       dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
 }
 
 static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
@@ -307,13 +315,13 @@ static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
        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);
 
-       if (atomic_dec_return(&cluster_usage[MAX_CLUSTERS]))
-               return;
-
-       for (i = 0; i < MAX_CLUSTERS; i++) {
+       for_each_present_cpu(i) {
                struct device *cdev = get_cpu_device(i);
                if (!cdev) {
                        pr_err("%s: failed to get cpu%d device\n", __func__, i);
@@ -324,34 +332,32 @@ static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
        }
 
        /* free virtual table */
-       kfree(freq_table[MAX_CLUSTERS]);
+       kfree(freq_table[cluster]);
 }
 
 static int _get_cluster_clk_and_freq_table(struct device *cpu_dev)
 {
-       u32 cluster = cpu_to_cluster(cpu_dev->id);
-       char name[14] = "cpu-cluster.X";
+       u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
        int ret;
 
-       if (atomic_inc_return(&cluster_usage[cluster]) != 1)
+       if (freq_table[cluster])
                return 0;
 
        ret = arm_bL_ops->init_opp_table(cpu_dev);
        if (ret) {
                dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
                                __func__, cpu_dev->id, ret);
-               goto atomic_dec;
+               goto out;
        }
 
-       ret = opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
+       ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
        if (ret) {
                dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
                                __func__, cpu_dev->id, ret);
-               goto atomic_dec;
+               goto free_opp_table;
        }
 
-       name[12] = cluster + '0';
-       clk[cluster] = clk_get_sys(name, NULL);
+       clk[cluster] = clk_get(cpu_dev, NULL);
        if (!IS_ERR(clk[cluster])) {
                dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
                                __func__, clk[cluster], freq_table[cluster],
@@ -362,10 +368,12 @@ static int _get_cluster_clk_and_freq_table(struct device *cpu_dev)
        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]);
-       opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
+       dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
 
-atomic_dec:
-       atomic_dec(&cluster_usage[cluster]);
+free_opp_table:
+       if (arm_bL_ops->free_opp_table)
+               arm_bL_ops->free_opp_table(cpu_dev);
+out:
        dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
                        cluster);
        return ret;
@@ -376,17 +384,21 @@ static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
        u32 cluster = cpu_to_cluster(cpu_dev->id);
        int i, ret;
 
-       if (cluster < MAX_CLUSTERS)
-               return _get_cluster_clk_and_freq_table(cpu_dev);
-
-       if (atomic_inc_return(&cluster_usage[MAX_CLUSTERS]) != 1)
+       if (atomic_inc_return(&cluster_usage[cluster]) != 1)
                return 0;
 
+       if (cluster < MAX_CLUSTERS) {
+               ret = _get_cluster_clk_and_freq_table(cpu_dev);
+               if (ret)
+                       atomic_dec(&cluster_usage[cluster]);
+               return ret;
+       }
+
        /*
         * Get data for all clusters and fill virtual cluster with a merge of
         * both
         */
-       for (i = 0; i < MAX_CLUSTERS; i++) {
+       for_each_present_cpu(i) {
                struct device *cdev = get_cpu_device(i);
                if (!cdev) {
                        pr_err("%s: failed to get cpu%d device\n", __func__, i);
@@ -412,7 +424,7 @@ static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
        return 0;
 
 put_clusters:
-       while (i--) {
+       for_each_present_cpu(i) {
                struct device *cdev = get_cpu_device(i);
                if (!cdev) {
                        pr_err("%s: failed to get cpu%d device\n", __func__, i);
@@ -422,7 +434,7 @@ put_clusters:
                _put_cluster_clk_and_freq_table(cdev);
        }
 
-       atomic_dec(&cluster_usage[MAX_CLUSTERS]);
+       atomic_dec(&cluster_usage[cluster]);
 
        return ret;
 }
@@ -445,7 +457,7 @@ static int bL_cpufreq_init(struct cpufreq_policy *policy)
        if (ret)
                return ret;
 
-       ret = cpufreq_frequency_table_cpuinfo(policy, freq_table[cur_cluster]);
+       ret = cpufreq_table_validate_and_show(policy, freq_table[cur_cluster]);
        if (ret) {
                dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n",
                                policy->cpu, cur_cluster);
@@ -453,8 +465,6 @@ static int bL_cpufreq_init(struct cpufreq_policy *policy)
                return ret;
        }
 
-       cpufreq_frequency_table_get_attr(freq_table[cur_cluster], policy->cpu);
-
        if (cur_cluster < MAX_CLUSTERS) {
                int cpu;
 
@@ -473,32 +483,44 @@ static int bL_cpufreq_init(struct cpufreq_policy *policy)
        else
                policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
 
-       policy->cur = clk_get_cpu_rate(policy->cpu);
-
        if (is_bL_switching_enabled())
-               per_cpu(cpu_last_req_freq, policy->cpu) = policy->cur;
+               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;
 }
 
-/* Export freq_table to sysfs */
-static struct freq_attr *bL_cpufreq_attr[] = {
-       &cpufreq_freq_attr_scaling_available_freqs,
-       NULL,
-};
+static int bL_cpufreq_exit(struct cpufreq_policy *policy)
+{
+       struct device *cpu_dev;
+
+       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);
+       dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
+
+       return 0;
+}
 
 static struct cpufreq_driver bL_cpufreq_driver = {
        .name                   = "arm-big-little",
-       .flags                  = CPUFREQ_STICKY,
-       .verify                 = bL_cpufreq_verify_policy,
-       .target                 = bL_cpufreq_set_target,
+       .flags                  = CPUFREQ_STICKY |
+                                       CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
+                                       CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+       .verify                 = cpufreq_generic_frequency_table_verify,
+       .target_index           = bL_cpufreq_set_target,
        .get                    = bL_cpufreq_get_rate,
        .init                   = bL_cpufreq_init,
-       .have_governor_per_policy = true,
-       .attr                   = bL_cpufreq_attr,
+       .exit                   = bL_cpufreq_exit,
+       .attr                   = cpufreq_generic_attr,
 };
 
+#ifdef CONFIG_BL_SWITCHER
 static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
                                        unsigned long action, void *_arg)
 {
@@ -531,6 +553,20 @@ 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
+
 int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
 {
        int ret, i;
@@ -548,8 +584,7 @@ int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
 
        arm_bL_ops = ops;
 
-       ret = bL_switcher_get_enabled();
-       set_switching_enabled(ret);
+       set_switching_enabled(bL_switcher_get_enabled());
 
        for (i = 0; i < MAX_CLUSTERS; i++)
                mutex_init(&cluster_lock[i]);
@@ -560,7 +595,7 @@ int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
                                __func__, ops->name, ret);
                arm_bL_ops = NULL;
        } else {
-               ret = bL_switcher_register_notifier(&bL_switcher_notifier);
+               ret = __bLs_register_notifier();
                if (ret) {
                        cpufreq_unregister_driver(&bL_cpufreq_driver);
                        arm_bL_ops = NULL;
@@ -584,30 +619,15 @@ void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
        }
 
        bL_switcher_get_enabled();
-       bL_switcher_unregister_notifier(&bL_switcher_notifier);
+       __bLs_unregister_notifier();
        cpufreq_unregister_driver(&bL_cpufreq_driver);
        bL_switcher_put_enabled();
        pr_info("%s: Un-registered platform driver: %s\n", __func__,
                        arm_bL_ops->name);
-
-       /* For saving table get/put on every cpu in/out */
-       if (is_bL_switching_enabled()) {
-               put_cluster_clk_and_freq_table(get_cpu_device(0));
-       } else {
-               int i;
-
-               for (i = 0; i < MAX_CLUSTERS; i++) {
-                       struct device *cdev = get_cpu_device(i);
-                       if (!cdev) {
-                               pr_err("%s: failed to get cpu%d device\n",
-                                               __func__, i);
-                               return;
-                       }
-
-                       put_cluster_clk_and_freq_table(cdev);
-               }
-       }
-
        arm_bL_ops = NULL;
 }
 EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
+
+MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
+MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
+MODULE_LICENSE("GPL v2");