acpi-cpufreq: replace per_cpu with driver_data of policy

Drivers can store their internal per-policy information in
policy->driver_data, lets use it.

we have benefits after this replacing.
1) memory saving.
2) policy is shared by several cpus, per_cpu seems not correct. using
*driver_data* is more reasonable.
3) fix a memory leak in acpi_cpufreq_cpu_exit. as policy->cpu might
change during cpu hotplug. So sometimes we cant't free *data*, use
*driver_data* to fix it.
4) fix a zero return value of get_cur_freq_on_cpu. Only per_cpu of
policy->cpu is set to *data*, if we try to get cpufreq on other cpus, we
get zero instead of correct values. Use *driver_data* to fix it.

Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index 0136dfc..e7fcaa6 100644 (file)
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -72,8 +72,6 @@ struct acpi_cpufreq_data {
        cpumask_var_t freqdomain_cpus;
 };
 
-static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
-
 /* acpi_perf_data is a pointer to percpu data. */
 static struct acpi_processor_performance __percpu *acpi_perf_data;
 
@@ -144,7 +142,7 @@ static int _store_boost(int val)
 
 static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
 {
-       struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
+       struct acpi_cpufreq_data *data = policy->driver_data;
 
        return cpufreq_show_cpus(data->freqdomain_cpus, buf);
 }
@@ -327,7 +325,8 @@ static void drv_write(struct drv_cmd *cmd)
        put_cpu();
 }
 
-static u32 get_cur_val(const struct cpumask *mask)
+static u32
+get_cur_val(const struct cpumask *mask, struct acpi_cpufreq_data *data)
 {
        struct acpi_processor_performance *perf;
        struct drv_cmd cmd;
@@ -335,7 +334,7 @@ static u32 get_cur_val(const struct cpumask *mask)
        if (unlikely(cpumask_empty(mask)))
                return 0;
 
-       switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) {
+       switch (data->cpu_feature) {
        case SYSTEM_INTEL_MSR_CAPABLE:
                cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
                cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
@@ -346,7 +345,7 @@ static u32 get_cur_val(const struct cpumask *mask)
                break;
        case SYSTEM_IO_CAPABLE:
                cmd.type = SYSTEM_IO_CAPABLE;
-               perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data;
+               perf = data->acpi_data;
                cmd.addr.io.port = perf->control_register.address;
                cmd.addr.io.bit_width = perf->control_register.bit_width;
                break;
@@ -364,19 +363,24 @@ static u32 get_cur_val(const struct cpumask *mask)
 
 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 {
-       struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu);
+       struct acpi_cpufreq_data *data;
+       struct cpufreq_policy *policy;
        unsigned int freq;
        unsigned int cached_freq;
 
        pr_debug("get_cur_freq_on_cpu (%d)\n", cpu);
 
-       if (unlikely(data == NULL ||
-                    data->acpi_data == NULL || data->freq_table == NULL)) {
+       policy = cpufreq_cpu_get(cpu);
+       if (unlikely(!policy))
+               return 0;
+
+       data = policy->driver_data;
+       cpufreq_cpu_put(policy);
+       if (unlikely(!data || !data->acpi_data || !data->freq_table))
                return 0;
-       }
 
        cached_freq = data->freq_table[data->acpi_data->state].frequency;
-       freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
+       freq = extract_freq(get_cur_val(cpumask_of(cpu), data), data);
        if (freq != cached_freq) {
                /*
                 * The dreaded BIOS frequency change behind our back.
@@ -397,7 +401,7 @@ static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
        unsigned int i;
 
        for (i = 0; i < 100; i++) {
-               cur_freq = extract_freq(get_cur_val(mask), data);
+               cur_freq = extract_freq(get_cur_val(mask, data), data);
                if (cur_freq == freq)
                        return 1;
                udelay(10);
@@ -408,7 +412,7 @@ static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
                               unsigned int index)
 {
-       struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
+       struct acpi_cpufreq_data *data = policy->driver_data;
        struct acpi_processor_performance *perf;
        struct drv_cmd cmd;
        unsigned int next_perf_state = 0; /* Index into perf table */
@@ -673,7 +677,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
        }
 
        data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
-       per_cpu(acfreq_data, cpu) = data;
+       policy->driver_data = data;
 
        if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
                acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
@@ -843,19 +847,19 @@ err_free_mask:
        free_cpumask_var(data->freqdomain_cpus);
 err_free:
        kfree(data);
-       per_cpu(acfreq_data, cpu) = NULL;
+       policy->driver_data = NULL;
 
        return result;
 }
 
 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 {
-       struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
+       struct acpi_cpufreq_data *data = policy->driver_data;
 
        pr_debug("acpi_cpufreq_cpu_exit\n");
 
        if (data) {
-               per_cpu(acfreq_data, policy->cpu) = NULL;
+               policy->driver_data = NULL;
                acpi_processor_unregister_performance(data->acpi_data,
                                                      policy->cpu);
                free_cpumask_var(data->freqdomain_cpus);
@@ -868,7 +872,7 @@ static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 
 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 {
-       struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
+       struct acpi_cpufreq_data *data = policy->driver_data;
 
        pr_debug("acpi_cpufreq_resume\n");