cpufreq: acpi-cpufreq: Drop acpi_data from struct acpi_cpufreq_data

After commit 8cfcfd39 (acpi-cpufreq: Fix an ACPI perf unregister
issue) we store both a pointer to per-CPU data of the first policy
CPU and the number of that CPU which are redundant.

Since the CPU number has to be stored anyway for the unregistration,
the pointer to the CPU's per-CPU data may be dropped and we can
access the data in question via per_cpu_ptr().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/cpufreq/acpi-cpufreq.c

@@ -65,7 +65,6 @@ enum {
 #define MSR_K7_HWCR_CPB_DIS	(1ULL << 25)
 
 struct acpi_cpufreq_data {
-	struct acpi_processor_performance *acpi_data;
 	struct cpufreq_frequency_table *freq_table;
 	unsigned int resume;
 	unsigned int cpu_feature;
@@ -76,6 +75,11 @@ struct acpi_cpufreq_data {
 /* acpi_perf_data is a pointer to percpu data. */
 static struct acpi_processor_performance __percpu *acpi_perf_data;
 
+static inline struct acpi_processor_performance *to_perf_data(struct acpi_cpufreq_data *data)
+{
+	return per_cpu_ptr(acpi_perf_data, data->acpi_perf_cpu);
+}
+
 static struct cpufreq_driver acpi_cpufreq_driver;
 
 static unsigned int acpi_pstate_strict;
@@ -201,7 +205,7 @@ static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
 	struct acpi_processor_performance *perf;
 	int i;
 
-	perf = data->acpi_data;
+	perf = to_perf_data(data);
 
 	for (i = 0; i < perf->state_count; i++) {
 		if (value == perf->states[i].status)
@@ -220,7 +224,7 @@ static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
 	else
 		msr &= INTEL_MSR_RANGE;
 
-	perf = data->acpi_data;
+	perf = to_perf_data(data);
 
 	cpufreq_for_each_entry(pos, data->freq_table)
 		if (msr == perf->states[pos->driver_data].status)
@@ -346,7 +350,7 @@ get_cur_val(const struct cpumask *mask, struct acpi_cpufreq_data *data)
 		break;
 	case SYSTEM_IO_CAPABLE:
 		cmd.type = SYSTEM_IO_CAPABLE;
-		perf = data->acpi_data;
+		perf = to_perf_data(data);
 		cmd.addr.io.port = perf->control_register.address;
 		cmd.addr.io.bit_width = perf->control_register.bit_width;
 		break;
@@ -377,10 +381,10 @@ static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 
 	data = policy->driver_data;
 	cpufreq_cpu_put(policy);
-	if (unlikely(!data || !data->acpi_data || !data->freq_table))
+	if (unlikely(!data || !data->freq_table))
 		return 0;
 
-	cached_freq = data->freq_table[data->acpi_data->state].frequency;
+	cached_freq = data->freq_table[to_perf_data(data)->state].frequency;
 	freq = extract_freq(get_cur_val(cpumask_of(cpu), data), data);
 	if (freq != cached_freq) {
 		/*
@@ -419,12 +423,11 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 	unsigned int next_perf_state = 0; /* Index into perf table */
 	int result = 0;
 
-	if (unlikely(data == NULL ||
-	     data->acpi_data == NULL || data->freq_table == NULL)) {
+	if (unlikely(data == NULL || data->freq_table == NULL)) {
 		return -ENODEV;
 	}
 
-	perf = data->acpi_data;
+	perf = to_perf_data(data);
 	next_perf_state = data->freq_table[index].driver_data;
 	if (perf->state == next_perf_state) {
 		if (unlikely(data->resume)) {
@@ -487,8 +490,9 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 static unsigned long
 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
 {
-	struct acpi_processor_performance *perf = data->acpi_data;
+	struct acpi_processor_performance *perf;
 
+	perf = to_perf_data(data);
 	if (cpu_khz) {
 		/* search the closest match to cpu_khz */
 		unsigned int i;
@@ -677,18 +681,17 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 		goto err_free;
 	}
 
-	data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
+	perf = per_cpu_ptr(acpi_perf_data, cpu);
 	data->acpi_perf_cpu = cpu;
 	policy->driver_data = data;
 
 	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
 		acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 
-	result = acpi_processor_register_performance(data->acpi_data, cpu);
+	result = acpi_processor_register_performance(perf, cpu);
 	if (result)
 		goto err_free_mask;
 
-	perf = data->acpi_data;
 	policy->shared_type = perf->shared_type;
 
 	/*