diff options
| author | Kumar Gala <galak@kernel.crashing.org> | 2008-06-18 16:26:52 -0500 |
|---|---|---|
| committer | Kumar Gala <galak@kernel.crashing.org> | 2008-06-26 01:48:56 -0500 |
| commit | fc4033b2f8b1482022bff3d05505a1b1631bb6de (patch) | |
| tree | c84b275968011911d8c96acebe89aa2dd92323bf /arch/powerpc/kernel/idle_e500.S | |
| parent | 3dfa8773674e16f95f70a0e631e80c69390d04d7 (diff) | |
powerpc/85xx: add DOZE/NAP support for e500 core
The e500 core enter DOZE/NAP power-saving modes when the core go to
cpu_idle routine.
The power management default running mode is DOZE, If the user
echo 1 > /proc/sys/kernel/powersave-nap
the system will change to NAP running mode.
Signed-off-by: Dave Liu <daveliu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/idle_e500.S')
| -rw-r--r-- | arch/powerpc/kernel/idle_e500.S | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S new file mode 100644 index 000000000000..267adec2491b --- /dev/null +++ b/arch/powerpc/kernel/idle_e500.S @@ -0,0 +1,84 @@ +/* + * Copyright (C) 2008 Freescale Semiconductor, Inc. All rights reserved. + * Dave Liu <daveliu@freescale.com> + * copy from idle_6xx.S and modify for e500 based processor, + * implement the power_save function in idle. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/threads.h> +#include <asm/reg.h> +#include <asm/page.h> +#include <asm/cputable.h> +#include <asm/thread_info.h> +#include <asm/ppc_asm.h> +#include <asm/asm-offsets.h> + + .text + +_GLOBAL(e500_idle) + rlwinm r3,r1,0,0,31-THREAD_SHIFT /* current thread_info */ + lwz r4,TI_LOCAL_FLAGS(r3) /* set napping bit */ + ori r4,r4,_TLF_NAPPING /* so when we take an exception */ + stw r4,TI_LOCAL_FLAGS(r3) /* it will return to our caller */ + + /* Check if we can nap or doze, put HID0 mask in r3 */ + lis r3,0 +BEGIN_FTR_SECTION + lis r3,HID0_DOZE@h +END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE) + +BEGIN_FTR_SECTION + /* Now check if user enabled NAP mode */ + lis r4,powersave_nap@ha + lwz r4,powersave_nap@l(r4) + cmpwi 0,r4,0 + beq 1f + stwu r1,-16(r1) + mflr r0 + stw r0,20(r1) + bl flush_dcache_L1 + lwz r0,20(r1) + addi r1,r1,16 + mtlr r0 + lis r3,HID0_NAP@h +END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP) +1: + /* Go to NAP or DOZE now */ + mfspr r4,SPRN_HID0 + rlwinm r4,r4,0,~(HID0_DOZE|HID0_NAP|HID0_SLEEP) + or r4,r4,r3 + isync + mtspr SPRN_HID0,r4 + isync + + mfmsr r7 + oris r7,r7,MSR_WE@h + ori r7,r7,MSR_EE + msync + mtmsr r7 + isync +2: b 2b + +/* + * Return from NAP/DOZE mode, restore some CPU specific registers, + * r2 containing physical address of current. + * r11 points to the exception frame (physical address). + * We have to preserve r10. + */ +_GLOBAL(power_save_ppc32_restore) + lwz r9,_LINK(r11) /* interrupted in e500_idle */ + stw r9,_NIP(r11) /* make it do a blr */ + +#ifdef CONFIG_SMP + mfspr r12,SPRN_SPRG3 + lwz r11,TI_CPU(r12) /* get cpu number * 4 */ + slwi r11,r11,2 +#else + li r11,0 +#endif + b transfer_to_handler_cont |