diff options
Diffstat (limited to 'arch/powerpc/kernel/idle_e500.S')
| -rw-r--r-- | arch/powerpc/kernel/idle_e500.S | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S new file mode 100644 index 000000000..72c85b6f3 --- /dev/null +++ b/arch/powerpc/kernel/idle_e500.S @@ -0,0 +1,93 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * 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. + */ + +#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> +#include <asm/feature-fixups.h> + + .text + +_GLOBAL(e500_idle) + lwz r4,TI_LOCAL_FLAGS(r2) /* set napping bit */ + ori r4,r4,_TLF_NAPPING /* so when we take an exception */ + stw r4,TI_LOCAL_FLAGS(r2) /* it will return to our caller */ + +#ifdef CONFIG_PPC_E500MC + wrteei 1 +1: wait + + /* + * Guard against spurious wakeups (e.g. from a hypervisor) -- + * any real interrupt will cause us to return to LR due to + * _TLF_NAPPING. + */ + b 1b +#else + /* 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 +#endif /* !E500MC */ + +/* + * 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 + lwz r11,TASK_CPU(r2) /* get cpu number * 4 */ + slwi r11,r11,2 +#else + li r11,0 +#endif + + b transfer_to_handler_cont +_ASM_NOKPROBE_SYMBOL(power_save_ppc32_restore) |