From a560643e21e1ac10f7398b45111aecdd7f47a4a5 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Wed, 14 May 2008 14:30:48 +1000 Subject: [POWERPC] Defer processing of interrupts when the CPU wakes from sleep mode This provides a way to defer processing of an interrupt that wakes the processor out of sleep mode. On 32-bit platforms that use an interrupt to wake the processor, we have to have interrupts enabled in hardware at the point where we go to sleep, otherwise the processor will never wake up. However, because interrupts are logically disabled at this point, we don't want to process the interrupt straight away. This is handled by setting the _TLF_SLEEPING flag. When we get an interrupt and _TLF_SLEEPING is set, we firstly clear the MSR_EE (external interrupt enable) bit in the saved MSR value, and secondly we then return to the address in the link register, like we do for _TLF_NAPPING, but without actually handling the interrupt. Note that this is handled somewhat differently on powerbooks, so this new code will only be used on non-Apple machines. Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/entry_32.S | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch') diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 3a05e9f93d4..888a364043a 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -147,6 +147,7 @@ transfer_to_handler: lwz r12,TI_LOCAL_FLAGS(r9) mtcrf 0x01,r12 bt- 31-TLF_NAPPING,4f + bt- 31-TLF_SLEEPING,7f #endif /* CONFIG_6xx */ .globl transfer_to_handler_cont transfer_to_handler_cont: @@ -164,6 +165,13 @@ transfer_to_handler_cont: 4: rlwinm r12,r12,0,~_TLF_NAPPING stw r12,TI_LOCAL_FLAGS(r9) b power_save_6xx_restore + +7: rlwinm r12,r12,0,~_TLF_SLEEPING + stw r12,TI_LOCAL_FLAGS(r9) + lwz r9,_MSR(r11) /* if sleeping, clear MSR.EE */ + rlwinm r9,r9,0,~MSR_EE + lwz r12,_LINK(r11) /* and return to address in LR */ + b fast_exception_return #endif /* -- cgit v1.2.3