ACPI, intel_idle: Cleanup idle= internal variables
Having four variables for the same thing:
idle_halt, idle_nomwait, force_mwait and boot_option_idle_overrides
is rather confusing and unnecessary complex.
if idle= boot param is passed, only set up one variable:
boot_option_idle_overrides
Introduces following functional changes/fixes:
- intel_idle driver does not register if any idle=xy
boot param is passed.
- processor_idle.c will also not register a cpuidle driver
and get active if idle=halt is passed.
Before a cpuidle driver with one (C1, halt) state got registered
Now the default_idle function will be used which finally uses
the same idle call to enter sleep state (safe_halt()), but
without registering a whole cpuidle driver.
That means idle= param will always avoid cpuidle drivers to register
with one exception (same behavior as before):
idle=nomwait
may still register acpi_idle cpuidle driver, but C1 will not use
mwait, but hlt. This can be a workaround for IO based deeper sleep
states where C1 mwait causes problems.
Signed-off-by: Thomas Renninger <trenn@suse.de>
cc: x86@kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 57d1868..b647215 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -22,11 +22,6 @@
#include <asm/i387.h>
#include <asm/debugreg.h>
-unsigned long idle_halt;
-EXPORT_SYMBOL(idle_halt);
-unsigned long idle_nomwait;
-EXPORT_SYMBOL(idle_nomwait);
-
struct kmem_cache *task_xstate_cachep;
EXPORT_SYMBOL_GPL(task_xstate_cachep);
@@ -328,7 +323,7 @@
/*
* Idle related variables and functions
*/
-unsigned long boot_option_idle_override = 0;
+unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
EXPORT_SYMBOL(boot_option_idle_override);
/*
@@ -499,7 +494,6 @@
*
* idle=mwait overrides this decision and forces the usage of mwait.
*/
-static int __cpuinitdata force_mwait;
#define MWAIT_INFO 0x05
#define MWAIT_ECX_EXTENDED_INFO 0x01
@@ -509,7 +503,7 @@
{
u32 eax, ebx, ecx, edx;
- if (force_mwait)
+ if (boot_option_idle_override == IDLE_FORCE_MWAIT)
return 1;
if (c->cpuid_level < MWAIT_INFO)
@@ -629,9 +623,10 @@
if (!strcmp(str, "poll")) {
printk("using polling idle threads.\n");
pm_idle = poll_idle;
- } else if (!strcmp(str, "mwait"))
- force_mwait = 1;
- else if (!strcmp(str, "halt")) {
+ boot_option_idle_override = IDLE_POLL;
+ } else if (!strcmp(str, "mwait")) {
+ boot_option_idle_override = IDLE_FORCE_MWAIT;
+ } 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
@@ -640,8 +635,7 @@
* the boot_option_idle_override.
*/
pm_idle = default_idle;
- idle_halt = 1;
- return 0;
+ boot_option_idle_override = IDLE_HALT;
} else if (!strcmp(str, "nomwait")) {
/*
* If the boot option of "idle=nomwait" is added,
@@ -649,12 +643,10 @@
* states. In such case it won't touch the variable
* of boot_option_idle_override.
*/
- idle_nomwait = 1;
- return 0;
+ boot_option_idle_override = IDLE_NOMWAIT;
} else
return -1;
- boot_option_idle_override = 1;
return 0;
}
early_param("idle", idle_setup);