acpi-cpufreq: Fix some x86/x86-64 acpi-cpufreq driver issues

This patch addresses some issues in x86/x86-64 acpi-cpufreq driver:

1.  Current memory allocation for acpi_perf_data is actually open-coded
   alloc_percpu().  The patch defines and handles acpi_perf_data as percpu
   data.  The code will be cleaner and easier to be maintained with this
   change.

2. Won't load driver in acpi_cpufreq_early_init() failure case.

3. Add __init for acpi_cpufreq_early_init().

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

3 files changed, 19 insertions, 30 deletions

diff --git a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
index 32d04b083e38..705e13a30781 100644
--- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -68,7 +68,8 @@ struct acpi_cpufreq_data {
 };
 
 static struct acpi_cpufreq_data *drv_data[NR_CPUS];
-static struct acpi_processor_performance *acpi_perf_data[NR_CPUS];
+/* acpi_perf_data is a pointer to percpu data. */
+static struct acpi_processor_performance *acpi_perf_data;
 
 static struct cpufreq_driver acpi_cpufreq_driver;
 
@@ -508,24 +509,14 @@ acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
  * do _PDC and _PSD and find out the processor dependency for the
  * actual init that will happen later...
  */
-static int acpi_cpufreq_early_init(void)
+static int __init acpi_cpufreq_early_init(void)
 {
-        struct acpi_processor_performance *data;
-        unsigned int i, j;
-
         dprintk("acpi_cpufreq_early_init\n");
 
-        for_each_possible_cpu(i) {
-                data = kzalloc(sizeof(struct acpi_processor_performance),
-                               GFP_KERNEL);
-                if (!data) {
-                        for_each_possible_cpu(j) {
-                                kfree(acpi_perf_data[j]);
-                                acpi_perf_data[j] = NULL;
-                        }
-                        return -ENOMEM;
-                }
-                acpi_perf_data[i] = data;
+        acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
+        if (!acpi_perf_data) {
+                dprintk("Memory allocation error for acpi_perf_data.\n");
+                return -ENOMEM;
         }
 
         /* Do initialization in ACPI core */
@@ -574,14 +565,11 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 
         dprintk("acpi_cpufreq_cpu_init\n");
 
-        if (!acpi_perf_data[cpu])
-                return -ENODEV;
-
         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
         if (!data)
                 return -ENOMEM;
 
-        data->acpi_data = acpi_perf_data[cpu];
+        data->acpi_data = percpu_ptr(acpi_perf_data, cpu);
         drv_data[cpu] = data;
 
         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
@@ -778,24 +766,25 @@ static struct cpufreq_driver acpi_cpufreq_driver = {
 
 static int __init acpi_cpufreq_init(void)
 {
+        int ret;
+
         dprintk("acpi_cpufreq_init\n");
 
-        acpi_cpufreq_early_init();
+        ret = acpi_cpufreq_early_init();
+        if (ret)
+                return ret;
 
         return cpufreq_register_driver(&acpi_cpufreq_driver);
 }
 
 static void __exit acpi_cpufreq_exit(void)
 {
-        unsigned int i;
         dprintk("acpi_cpufreq_exit\n");
 
         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 
-        for_each_possible_cpu(i) {
-                kfree(acpi_perf_data[i]);
-                acpi_perf_data[i] = NULL;
-        }
+        free_percpu(acpi_perf_data);
+
         return;
 }
 
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index c4efc0c17f8f..463b0247cbc5 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -539,7 +539,7 @@ end:
 }
 
 int acpi_processor_preregister_performance(
-                struct acpi_processor_performance **performance)
+                struct acpi_processor_performance *performance)
 {
         int count, count_target;
         int retval = 0;
@@ -567,12 +567,12 @@ int acpi_processor_preregister_performance(
                         continue;
                 }
 
-                if (!performance || !performance[i]) {
+                if (!performance || !percpu_ptr(performance, i)) {
                         retval = -EINVAL;
                         continue;
                 }
 
-                pr->performance = performance[i];
+                pr->performance = percpu_ptr(performance, i);
                 cpu_set(i, pr->performance->shared_cpu_map);
                 if (acpi_processor_get_psd(pr)) {
                         retval = -EINVAL;
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index f9f987f8e661..ec3ffdadb4d2 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -232,7 +232,7 @@ struct acpi_processor_errata {
 
 extern int acpi_processor_preregister_performance(struct
                                                   acpi_processor_performance
-                                                  **performance);
+                                                  *performance);
 
 extern int acpi_processor_register_performance(struct acpi_processor_performance
                                                *performance, unsigned int cpu);