[ACPI] C1 fixes when processor driver is loaded

honor "halt=" cmdline parameter
use monitor/mwait when available
http://bugzilla.kernel.org/show_bug.cgi?id=2280Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

arch/i386/kernel/process.c

@@ -57,6 +57,9 @@ asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 
 int hlt_counter;
 
+unsigned long boot_option_idle_override = 0;
+EXPORT_SYMBOL(boot_option_idle_override);
+
 /*
  * Return saved PC of a blocked thread.
  */
@@ -211,6 +214,7 @@ static int __init idle_setup (char *str)
 		pm_idle = default_idle;
 	}
 
+	boot_option_idle_override = 1;
 	return 1;
 }
 

arch/ia64/kernel/process.c

@@ -47,6 +47,8 @@
 
 void (*ia64_mark_idle)(int);
 
+unsigned long boot_option_idle_override = 0;
+EXPORT_SYMBOL(boot_option_idle_override);
 
 void
 ia64_do_show_stack (struct unw_frame_info *info, void *arg)

arch/x86_64/kernel/process.c

@@ -54,6 +54,9 @@ unsigned long kernel_thread_flags = CLONE_VM | CLONE_UNTRACED;
 
 atomic_t hlt_counter = ATOMIC_INIT(0);
 
+unsigned long boot_option_idle_override = 0;
+EXPORT_SYMBOL(boot_option_idle_override);
+
 /*
  * Powermanagement idle function, if any..
  */
@@ -192,6 +195,7 @@ static int __init idle_setup (char *str)
 		pm_idle = poll_idle;
 	}
 
+	boot_option_idle_override = 1;
 	return 1;
 }
 

drivers/acpi/processor.c

@@ -411,8 +411,15 @@ acpi_processor_idle (void)
 	switch (pr->power.state) {
 
 	case ACPI_STATE_C1:
-		/* Invoke C1. */
-		safe_halt();
+		/*
+		 * Invoke C1.
+		 * Use the appropriate idle routine, the one that would
+		 * be used without acpi C-states.
+		 */
+		if (pm_idle_save)
+			pm_idle_save();
+		else
+			safe_halt();
 		/*
                  * TBD: Can't get time duration while in C1, as resumes
 		 *      go to an ISR rather than here.  Need to instrument
@@ -2388,22 +2395,28 @@ acpi_processor_add (
 
 	/*
 	 * Install the idle handler if processor power management is supported.
-	 * Note that the default idle handler (default_idle) will be used on 
+	 * Note that we use previously set idle handler will be used on 
 	 * platforms that only support C1.
 	 */
-	if ((pr->id == 0) && (pr->flags.power)) {
-		pm_idle_save = pm_idle;
-		pm_idle = acpi_processor_idle;
+	if ((pr->flags.power) && (!boot_option_idle_override)) {
+		printk(KERN_INFO PREFIX "%s [%s] (supports",
+			acpi_device_name(device), acpi_device_bid(device));
+		for (i = 1; i < ACPI_C_STATE_COUNT; i++)
+			if (pr->power.states[i].valid)
+				printk(" C%d", i);
+		printk(")\n");
+		if (pr->id == 0) {
+			pm_idle_save = pm_idle;
+			pm_idle = acpi_processor_idle;
+		}
 	}
 	
-	printk(KERN_INFO PREFIX "%s [%s] (supports",
-		acpi_device_name(device), acpi_device_bid(device));
-	for (i=1; i<ACPI_C_STATE_COUNT; i++)
-		if (pr->power.states[i].valid)
-			printk(" C%d", i);
-	if (pr->flags.throttling)
-		printk(", %d throttling states", pr->throttling.state_count);
-	printk(")\n");
+	if (pr->flags.throttling) {
+		printk(KERN_INFO PREFIX "%s [%s] (supports",
+			acpi_device_name(device), acpi_device_bid(device));
+		printk(" %d throttling states", pr->throttling.state_count);
+		printk(")\n");
+	}
 
 end:
 	if (result) {

include/asm-i386/processor.h

@@ -650,4 +650,6 @@ extern void select_idle_routine(const struct cpuinfo_x86 *c);
 #define ARCH_HAS_SCHED_WAKE_IDLE
 #endif
 
+extern unsigned long boot_option_idle_override;
+
 #endif /* __ASM_I386_PROCESSOR_H */

include/asm-ia64/processor.h

@@ -688,6 +688,8 @@ prefetchw (const void *x)
 
 #define spin_lock_prefetch(x)	prefetchw(x)
 
+extern unsigned long boot_option_idle_override;
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* _ASM_IA64_PROCESSOR_H */

include/asm-x86_64/processor.h

@@ -461,4 +461,6 @@ static inline void __mwait(unsigned long eax, unsigned long ecx)
 #define ARCH_HAS_SCHED_WAKE_IDLE
 #endif
 
+extern unsigned long boot_option_idle_override;
+
 #endif /* __ASM_X86_64_PROCESSOR_H */