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[ACPI] Add support for FADT P_LVL2_UP flag 

which tells us if C2 is valid for UP-only, or SMP.

As there is no separate bit for C3,  use P_LVL2_UP
bit to cover both C2 and C3.

http://bugzilla.kernel.org/show_bug.cgi?id=5165

Signed-off-by: Venkatesh Pallipadi<venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
(cherry picked from 28b86b368af3944eb383078fc5797caf2dc8ce44 commit)
hifive-unleashed-5.1
Venkatesh Pallipadi 2005-09-15 12:20:00 -04:00 committed by Len Brown
parent 6d93c64803
commit 4c0335526c
1 changed files with 19 additions and 0 deletions
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19
drivers/acpi/processor_idle.c
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@ -280,6 +280,16 @@ static void acpi_processor_idle(void)
cx->usage++;
#ifdef CONFIG_HOTPLUG_CPU
/*
* Check for P_LVL2_UP flag before entering C2 and above on
* an SMP system. We do it here instead of doing it at _CST/P_LVL
* detection phase, to work cleanly with logical CPU hotplug.
*/
if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
!pr->flags.has_cst && acpi_fadt.plvl2_up)
cx->type = ACPI_STATE_C1;
#endif
/*
* Sleep:
* ------
@ -534,6 +544,15 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
pr->power.states[ACPI_STATE_C0].valid = 1;
pr->power.states[ACPI_STATE_C1].valid = 1;
#ifndef CONFIG_HOTPLUG_CPU
/*
* Check for P_LVL2_UP flag before entering C2 and above on
* an SMP system.
*/
if ((num_online_cpus() > 1) && acpi_fadt.plvl2_up)
return_VALUE(-ENODEV);
#endif
/* determine C2 and C3 address from pblk */
pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;