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| author | Hans-Christian Egtvedt <hcegtvedt@atmel.com> | 2007-02-26 13:50:43 +0100 |
|---|---|---|
| committer | Haavard Skinnemoen <hskinnemoen@atmel.com> | 2007-04-27 13:44:12 +0200 |
| commit | 19b7ce8bad718a2850ea19aeb7383f1728596c24 (patch) | |
| tree | 1fef17c37eaf90231a497b92dd49565e56986b6c /arch/avr32 | |
| parent | [AVR32] Change system timer from count-compare to Timer/Counter 0 (diff) | |
| download | linux-19b7ce8bad718a2850ea19aeb7383f1728596c24.tar.xz linux-19b7ce8bad718a2850ea19aeb7383f1728596c24.zip | |
[AVR32] Put cpu in sleep 0 when idle.
This patch puts the CPU in sleep 0 when doing nothing, idle. This will
turn of the CPU clock and thus save power. The CPU is waken again when
an interrupt occurs.
Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Diffstat (limited to 'arch/avr32')
| -rw-r--r-- | arch/avr32/kernel/entry-avr32b.S | 42 | ||||
| -rw-r--r-- | arch/avr32/kernel/process.c | 5 |
2 files changed, 40 insertions, 7 deletions
diff --git a/arch/avr32/kernel/entry-avr32b.S b/arch/avr32/kernel/entry-avr32b.S index eeb66792bc37..5f5f7e42f51b 100644 --- a/arch/avr32/kernel/entry-avr32b.S +++ b/arch/avr32/kernel/entry-avr32b.S @@ -630,9 +630,12 @@ irq_level\level: rcall do_IRQ lddsp r4, sp[REG_SR] - andh r4, (MODE_MASK >> 16), COH + bfextu r4, r4, SYSREG_M0_OFFSET, 3 + cp.w r4, MODE_SUPERVISOR >> SYSREG_M0_OFFSET + breq 2f + cp.w r4, MODE_USER >> SYSREG_M0_OFFSET #ifdef CONFIG_PREEMPT - brne 2f + brne 3f #else brne 1f #endif @@ -649,9 +652,18 @@ irq_level\level: sub sp, -4 /* ignore r12_orig */ rete +2: get_thread_info r0 + ld.w r1, r0[TI_flags] + bld r1, TIF_CPU_GOING_TO_SLEEP #ifdef CONFIG_PREEMPT -2: - get_thread_info r0 + brcc 3f +#else + brcc 1b +#endif + sub r1, pc, . - cpu_idle_skip_sleep + stdsp sp[REG_PC], r1 +#ifdef CONFIG_PREEMPT +3: get_thread_info r0 ld.w r2, r0[TI_preempt_count] cp.w r2, 0 brne 1b @@ -662,12 +674,32 @@ irq_level\level: bld r4, SYSREG_GM_OFFSET brcs 1b rcall preempt_schedule_irq - rjmp 1b #endif + rjmp 1b .endm .section .irq.text,"ax",@progbits +.global cpu_idle_sleep +cpu_idle_sleep: + mask_interrupts + get_thread_info r8 + ld.w r9, r8[TI_flags] + bld r9, TIF_NEED_RESCHED + brcs cpu_idle_enable_int_and_exit + sbr r9, TIF_CPU_GOING_TO_SLEEP + st.w r8[TI_flags], r9 + unmask_interrupts + sleep 0 +cpu_idle_skip_sleep: + mask_interrupts + ld.w r9, r8[TI_flags] + cbr r9, TIF_CPU_GOING_TO_SLEEP + st.w r8[TI_flags], r9 +cpu_idle_enable_int_and_exit: + unmask_interrupts + retal r12 + .global irq_level0 .global irq_level1 .global irq_level2 diff --git a/arch/avr32/kernel/process.c b/arch/avr32/kernel/process.c index 0b4325946a41..4f8d2d474740 100644 --- a/arch/avr32/kernel/process.c +++ b/arch/avr32/kernel/process.c @@ -19,6 +19,8 @@ void (*pm_power_off)(void) = NULL; EXPORT_SYMBOL(pm_power_off); +extern void cpu_idle_sleep(void); + /* * This file handles the architecture-dependent parts of process handling.. */ @@ -27,9 +29,8 @@ void cpu_idle(void) { /* endless idle loop with no priority at all */ while (1) { - /* TODO: Enter sleep mode */ while (!need_resched()) - cpu_relax(); + cpu_idle_sleep(); preempt_enable_no_resched(); schedule(); preempt_disable(); |