APM idle: register apm_cpu_idle via cpuidle

Update APM to register its local idle routine with cpuidle.

This allows us to stop exporting pm_idle to modules on x86.

The Kconfig sub-option, APM_CPU_IDLE, now depends on on CPU_IDLE.

Compile-tested only.

Signed-off-by: Len Brown <len.brown@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Jiri Kosina <jkosina@suse.cz>

3 files changed, 35 insertions, 26 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 225543bf45a5..1b635861401c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1912,6 +1912,7 @@ config APM_DO_ENABLE
           this feature.
 
 config APM_CPU_IDLE
+        depends on CPU_IDLE
         bool "Make CPU Idle calls when idle"
         ---help---
           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c
index d65464e43503..9f4bc6a1164d 100644
--- a/arch/x86/kernel/apm_32.c
+++ b/arch/x86/kernel/apm_32.c
@@ -232,6 +232,7 @@
 #include <linux/acpi.h>
 #include <linux/syscore_ops.h>
 #include <linux/i8253.h>
+#include <linux/cpuidle.h>
 
 #include <asm/uaccess.h>
 #include <asm/desc.h>
@@ -360,13 +361,35 @@ struct apm_user {
  * idle percentage above which bios idle calls are done
  */
 #ifdef CONFIG_APM_CPU_IDLE
-#warning deprecated CONFIG_APM_CPU_IDLE will be deleted in 2012
 #define DEFAULT_IDLE_THRESHOLD  95
 #else
 #define DEFAULT_IDLE_THRESHOLD  100
 #endif
 #define DEFAULT_IDLE_PERIOD     (100 / 3)
 
+static int apm_cpu_idle(struct cpuidle_device *dev,
+                        struct cpuidle_driver *drv, int index);
+
+static struct cpuidle_driver apm_idle_driver = {
+        .name = "apm_idle",
+        .owner = THIS_MODULE,
+        .en_core_tk_irqen = 1,
+        .states = {
+                { /* entry 0 is for polling */ },
+                { /* entry 1 is for APM idle */
+                        .name = "APM",
+                        .desc = "APM idle",
+                        .flags = CPUIDLE_FLAG_TIME_VALID,
+                        .exit_latency = 250,    /* WAG */
+                        .target_residency = 500,        /* WAG */
+                        .enter = &apm_cpu_idle
+                },
+        },
+        .state_count = 2,
+};
+
+static struct cpuidle_device apm_cpuidle_device;
+
 /*
  * Local variables
  */
@@ -377,7 +400,6 @@ static struct {
 static int clock_slowed;
 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
-static int set_pm_idle;
 static int suspends_pending;
 static int standbys_pending;
 static int ignore_sys_suspend;
@@ -884,8 +906,6 @@ static void apm_do_busy(void)
 #define IDLE_CALC_LIMIT (HZ * 100)
 #define IDLE_LEAKY_MAX  16
 
-static void (*original_pm_idle)(void) __read_mostly;
-
 /**
  * apm_cpu_idle         -       cpu idling for APM capable Linux
  *
@@ -894,7 +914,8 @@ static void (*original_pm_idle)(void) __read_mostly;
  * Furthermore it calls the system default idle routine.
  */
 
-static void apm_cpu_idle(void)
+static int apm_cpu_idle(struct cpuidle_device *dev,
+        struct cpuidle_driver *drv, int index)
 {
         static int use_apm_idle; /* = 0 */
         static unsigned int last_jiffies; /* = 0 */
@@ -904,7 +925,6 @@ static void apm_cpu_idle(void)
         unsigned int jiffies_since_last_check = jiffies - last_jiffies;
         unsigned int bucket;
 
-        WARN_ONCE(1, "deprecated apm_cpu_idle will be deleted in 2012");
 recalc:
         if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
                 use_apm_idle = 0;
@@ -950,10 +970,7 @@ recalc:
                                 break;
                         }
                 }
-                if (original_pm_idle)
-                        original_pm_idle();
-                else
-                        default_idle();
+                default_idle();
                 local_irq_disable();
                 jiffies_since_last_check = jiffies - last_jiffies;
                 if (jiffies_since_last_check > idle_period)
@@ -963,7 +980,7 @@ recalc:
         if (apm_idle_done)
                 apm_do_busy();
 
-        local_irq_enable();
+        return index;
 }
 
 /**
@@ -2381,9 +2398,9 @@ static int __init apm_init(void)
         if (HZ != 100)
                 idle_period = (idle_period * HZ) / 100;
         if (idle_threshold < 100) {
-                original_pm_idle = pm_idle;
-                pm_idle  = apm_cpu_idle;
-                set_pm_idle = 1;
+                if (!cpuidle_register_driver(&apm_idle_driver))
+                        if (cpuidle_register_device(&apm_cpuidle_device))
+                                cpuidle_unregister_driver(&apm_idle_driver);
         }
 
         return 0;
@@ -2393,15 +2410,9 @@ static void __exit apm_exit(void)
 {
         int error;
 
-        if (set_pm_idle) {
-                pm_idle = original_pm_idle;
-                /*
-                 * We are about to unload the current idle thread pm callback
-                 * (pm_idle), Wait for all processors to update cached/local
-                 * copies of pm_idle before proceeding.
-                 */
-                kick_all_cpus_sync();
-        }
+        cpuidle_unregister_device(&apm_cpuidle_device);
+        cpuidle_unregister_driver(&apm_idle_driver);
+
         if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
             && (apm_info.connection_version > 0x0100)) {
                 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 2ed787f15bf0..f571a6e08710 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -272,9 +272,6 @@ EXPORT_SYMBOL(boot_option_idle_override);
  * Powermanagement idle function, if any..
  */
 void (*pm_idle)(void);
-#ifdef CONFIG_APM_MODULE
-EXPORT_SYMBOL(pm_idle);
-#endif
 
 #ifndef CONFIG_SMP
 static inline void play_dead(void)