[RFC PATCH 2/4] cpufreq: arm_big_little: remove big.LITTLE switcher support
Bartlomiej Zolnierkiewicz
b.zolnierkie at samsung.com
Mon Jun 27 04:26:08 PDT 2016
Remove no longer needed big.LITTLE switcher support from
arm_big_little CPUfreq driver.
The arm_big_little CPUfreq driver itself may also be removed
at later time (after converting platforms using it to use
cpufreq-dt CPUfreq driver instead).
Cc: Sudeep Holla <sudeep.holla at arm.com>
Cc: Sudeep KarkadaNagesha <sudeep.karkadanagesha at arm.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>
---
drivers/cpufreq/arm_big_little.c | 379 +++------------------------------------
1 file changed, 24 insertions(+), 355 deletions(-)
diff --git a/drivers/cpufreq/arm_big_little.c b/drivers/cpufreq/arm_big_little.c
index 4180422..02bf55b 100644
--- a/drivers/cpufreq/arm_big_little.c
+++ b/drivers/cpufreq/arm_big_little.c
@@ -36,116 +36,37 @@
#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 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];
-
-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 struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS];
+static atomic_t cluster_usage[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;
- }
-
- pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
- max_freq);
-
- return max_freq;
-}
-
static unsigned int clk_get_cpu_rate(unsigned int cpu)
{
- u32 cur_cluster = per_cpu(physical_cluster, cpu);
+ u32 cur_cluster = raw_cpu_to_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);
-
pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
cur_cluster, rate);
return rate;
}
-static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
-{
- if (is_bL_switching_enabled()) {
- pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
- cpu));
-
- return per_cpu(cpu_last_req_freq, cpu);
- } else {
- return clk_get_cpu_rate(cpu);
- }
-}
-
static unsigned int
bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
{
- u32 new_rate, prev_rate;
+ u32 new_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;
- }
+ new_rate = rate;
pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
__func__, cpu, old_cluster, new_cluster, new_rate);
@@ -167,43 +88,10 @@ bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
if (WARN_ON(ret)) {
pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
new_cluster);
- 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) {
- pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
- __func__, cpu, 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) {
- pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
- __func__, old_cluster, new_rate);
-
- if (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;
}
@@ -211,91 +99,14 @@ bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
unsigned int index)
{
- u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
+ u32 cpu = policy->cpu, cur_cluster;
unsigned int freqs_new;
- cur_cluster = cpu_to_cluster(cpu);
- new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
+ cur_cluster = raw_cpu_to_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;
- }
- }
-
- return bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
-}
-
-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;
- uint32_t 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;
- uint32_t max_freq = 0;
- cpufreq_for_each_entry(pos, table)
- if (pos->frequency > max_freq)
- max_freq = pos->frequency;
- return max_freq;
-}
-
-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 = kzalloc(sizeof(*table) * count, 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--) {
- for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
- j++) {
- table[k].frequency = VIRT_FREQ(i,
- freq_table[i][j].frequency);
- pr_debug("%s: index: %d, freq: %d\n", __func__, k,
- table[k].frequency);
- k++;
- }
- }
-
- table[k].driver_data = k;
- table[k].frequency = CPUFREQ_TABLE_END;
-
- pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
-
- return 0;
+ return bL_cpufreq_set_rate(cpu, cur_cluster, cur_cluster, freqs_new);
}
static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
@@ -316,27 +127,12 @@ static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
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;
+ u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
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) {
- pr_err("%s: failed to get cpu%d device\n", __func__, i);
- return;
- }
-
- _put_cluster_clk_and_freq_table(cdev, cpumask);
- }
-
- /* free virtual table */
- kfree(freq_table[cluster]);
+ return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
}
static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
@@ -387,68 +183,22 @@ out:
static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
const struct cpumask *cpumask)
{
- u32 cluster = cpu_to_cluster(cpu_dev->id);
- int i, ret;
+ u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
+ int 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) {
- pr_err("%s: failed to get cpu%d device\n", __func__, i);
- return -ENODEV;
- }
-
- ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
- if (ret)
- goto put_clusters;
- }
-
- ret = merge_cluster_tables();
+ ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
if (ret)
- goto put_clusters;
-
- /* Assuming 2 cluster, set clk_big_min and clk_little_max */
- clk_big_min = get_table_min(freq_table[0]);
- clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
-
- pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
- __func__, cluster, clk_big_min, clk_little_max);
-
- return 0;
-
-put_clusters:
- 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);
- return -ENODEV;
- }
-
- _put_cluster_clk_and_freq_table(cdev, cpumask);
- }
-
- atomic_dec(&cluster_usage[cluster]);
-
+ atomic_dec(&cluster_usage[cluster]);
return ret;
}
/* Per-CPU initialization */
static int bL_cpufreq_init(struct cpufreq_policy *policy)
{
- u32 cur_cluster = cpu_to_cluster(policy->cpu);
+ u32 cur_cluster = raw_cpu_to_cluster(policy->cpu);
struct device *cpu_dev;
int ret;
@@ -459,17 +209,7 @@ static int bL_cpufreq_init(struct cpufreq_policy *policy)
return -ENODEV;
}
- if (cur_cluster < MAX_CLUSTERS) {
- int cpu;
-
- cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
-
- 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;
- }
+ cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
if (ret)
@@ -489,9 +229,6 @@ static int bL_cpufreq_init(struct cpufreq_policy *policy)
else
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
- 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;
}
@@ -499,12 +236,10 @@ static int bL_cpufreq_init(struct cpufreq_policy *policy)
static int bL_cpufreq_exit(struct cpufreq_policy *policy)
{
struct device *cpu_dev;
- int cur_cluster = cpu_to_cluster(policy->cpu);
+ int cur_cluster = raw_cpu_to_cluster(policy->cpu);
- if (cur_cluster < MAX_CLUSTERS) {
- cpufreq_cooling_unregister(cdev[cur_cluster]);
- cdev[cur_cluster] = NULL;
- }
+ cpufreq_cooling_unregister(cdev[cur_cluster]);
+ cdev[cur_cluster] = NULL;
cpu_dev = get_cpu_device(policy->cpu);
if (!cpu_dev) {
@@ -522,13 +257,9 @@ static int bL_cpufreq_exit(struct cpufreq_policy *policy)
static void bL_cpufreq_ready(struct cpufreq_policy *policy)
{
struct device *cpu_dev = get_cpu_device(policy->cpu);
- int cur_cluster = cpu_to_cluster(policy->cpu);
+ int cur_cluster = raw_cpu_to_cluster(policy->cpu);
struct device_node *np;
- /* Do not register a cpu_cooling device if we are in IKS mode */
- if (cur_cluster >= MAX_CLUSTERS)
- return;
-
np = of_node_get(cpu_dev->of_node);
if (WARN_ON(!np))
return;
@@ -558,63 +289,16 @@ static struct cpufreq_driver bL_cpufreq_driver = {
CPUFREQ_NEED_INITIAL_FREQ_CHECK,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = bL_cpufreq_set_target,
- .get = bL_cpufreq_get_rate,
+ .get = clk_get_cpu_rate,
.init = bL_cpufreq_init,
.exit = bL_cpufreq_exit,
.ready = bL_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(&bL_cpufreq_driver);
- break;
-
- case BL_NOTIFY_POST_ENABLE:
- set_switching_enabled(true);
- cpufreq_register_driver(&bL_cpufreq_driver);
- break;
-
- case BL_NOTIFY_POST_DISABLE:
- set_switching_enabled(false);
- cpufreq_register_driver(&bL_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
-
int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
{
- int ret, i;
+ int ret;
if (arm_bL_ops) {
pr_debug("%s: Already registered: %s, exiting\n", __func__,
@@ -629,28 +313,16 @@ int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
arm_bL_ops = ops;
- set_switching_enabled(bL_switcher_get_enabled());
-
- 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",
__func__, ops->name, ret);
arm_bL_ops = NULL;
} else {
- ret = __bLs_register_notifier();
- if (ret) {
- cpufreq_unregister_driver(&bL_cpufreq_driver);
- arm_bL_ops = NULL;
- } else {
- pr_info("%s: Registered platform driver: %s\n",
- __func__, ops->name);
- }
+ pr_info("%s: Registered platform driver: %s\n",
+ __func__, ops->name);
}
- bL_switcher_put_enabled();
return ret;
}
EXPORT_SYMBOL_GPL(bL_cpufreq_register);
@@ -663,10 +335,7 @@ void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
return;
}
- bL_switcher_get_enabled();
- __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);
arm_bL_ops = NULL;
--
1.9.1
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