Merge branch 'release-2.6.27' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-acpi-merge-2.6

* 'release-2.6.27' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-acpi-merge-2.6: (87 commits)
  Fix FADT parsing
  Add the ability to reset the machine using the RESET_REG in ACPI's FADT table.
  ACPI: use dev_printk when possible
  PNPACPI: add support for HP vendor-specific CCSR descriptors
  PNP: avoid legacy IDE IRQs
  PNP: convert resource options to single linked list
  ISAPNP: handle independent options following dependent ones
  PNP: remove extra 0x100 bit from option priority
  PNP: support optional IRQ resources
  PNP: rename pnp_register_*_resource() local variables
  PNPACPI: ignore _PRS interrupt numbers larger than PNP_IRQ_NR
  PNP: centralize resource option allocations
  PNP: remove redundant pnp_can_configure() check
  PNP: make resource assignment functions return 0 (success) or -EBUSY (failure)
  PNP: in debug resource dump, make empty list obvious
  PNP: improve resource assignment debug
  PNP: increase I/O port & memory option address sizes
  PNP: introduce pnp_irq_mask_t typedef
  PNP: make resource option structures private to PNP subsystem
  PNP: define PNP-specific IORESOURCE_IO_* flags alongside IRQ, DMA, MEM
  ...

1 files changed, 27 insertions, 1 deletions

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 7dceea94723..4d629c62f4f 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -7,6 +7,12 @@
 #include <linux/module.h>
 #include <linux/pm.h>
 #include <linux/clockchips.h>
+#include <asm/system.h>
+
+unsigned long idle_halt;
+EXPORT_SYMBOL(idle_halt);
+unsigned long idle_nomwait;
+EXPORT_SYMBOL(idle_nomwait);
 
 struct kmem_cache *task_xstate_cachep;
 
@@ -325,7 +331,27 @@ static int __init idle_setup(char *str)
 		pm_idle = poll_idle;
 	} else if (!strcmp(str, "mwait"))
 		force_mwait = 1;
-	else
+	else if (!strcmp(str, "halt")) {
+		/*
+		 * When the boot option of idle=halt is added, halt is
+		 * forced to be used for CPU idle. In such case CPU C2/C3
+		 * won't be used again.
+		 * To continue to load the CPU idle driver, don't touch
+		 * the boot_option_idle_override.
+		 */
+		pm_idle = default_idle;
+		idle_halt = 1;
+		return 0;
+	} else if (!strcmp(str, "nomwait")) {
+		/*
+		 * If the boot option of "idle=nomwait" is added,
+		 * it means that mwait will be disabled for CPU C2/C3
+		 * states. In such case it won't touch the variable
+		 * of boot_option_idle_override.
+		 */
+		idle_nomwait = 1;
+		return 0;
+	} else
 		return -1;
 
 	boot_option_idle_override = 1;