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author | Anton Blanchard <anton@samba.org> | 2011-11-23 20:07:22 +0000 |
---|---|---|
committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-11-25 14:11:26 +1100 |
commit | 7df1027542c9353bef4d027cb4ab8e99f69017b7 (patch) | |
tree | 297c93c0937a05a66235f24fbab1c58e8dd93514 /arch/powerpc/kernel | |
parent | 621692cb7efb6d0e38c62e41844a6360c6719b20 (diff) | |
download | op-kernel-dev-7df1027542c9353bef4d027cb4ab8e99f69017b7.zip op-kernel-dev-7df1027542c9353bef4d027cb4ab8e99f69017b7.tar.gz |
powerpc/time: Optimise decrementer_check_overflow
decrementer_check_overflow is called from arch_local_irq_restore so
we want to make it as light weight as possible. As such, turn
decrementer_check_overflow into an inline function.
To avoid a circular mess of includes, separate out the two components
of struct decrementer_clock and keep the struct clock_event_device
part local to time.c.
The fast path improves from:
arch_local_irq_restore
0: mflr r0
4: std r0,16(r1)
8: stdu r1,-112(r1)
c: stb r3,578(r13)
10: cmpdi cr7,r3,0
14: beq- cr7,24 <.arch_local_irq_restore+0x24>
...
24: addi r1,r1,112
28: ld r0,16(r1)
2c: mtlr r0
30: blr
to:
arch_local_irq_restore
0: std r30,-16(r1)
4: ld r30,0(r2)
8: stb r3,578(r13)
c: cmpdi cr7,r3,0
10: beq- cr7,6c <.arch_local_irq_restore+0x6c>
...
6c: ld r30,-16(r1)
70: blr
Unfortunately we still setup a local TOC (due to -mminimal-toc). Yet
another sign we should be moving to -mcmodel=medium.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel')
-rw-r--r-- | arch/powerpc/kernel/irq.c | 9 | ||||
-rw-r--r-- | arch/powerpc/kernel/time.c | 27 |
2 files changed, 16 insertions, 20 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 745c1e7..2ff4f5e 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -115,6 +115,15 @@ static inline notrace void set_soft_enabled(unsigned long enable) : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled))); } +static inline notrace void decrementer_check_overflow(void) +{ + u64 now = get_tb_or_rtc(); + u64 *next_tb = &__get_cpu_var(decrementers_next_tb); + + if (now >= *next_tb) + set_dec(1); +} + notrace void arch_local_irq_restore(unsigned long en) { /* diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index b1990b9..9754743 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -114,12 +114,8 @@ static struct clock_event_device decrementer_clockevent = { .features = CLOCK_EVT_FEAT_ONESHOT, }; -struct decrementer_clock { - struct clock_event_device event; - u64 next_tb; -}; - -static DEFINE_PER_CPU(struct decrementer_clock, decrementers); +DEFINE_PER_CPU(u64, decrementers_next_tb); +static DEFINE_PER_CPU(struct clock_event_device, decrementers); #ifdef CONFIG_PPC_ISERIES static unsigned long __initdata iSeries_recal_titan; @@ -570,8 +566,8 @@ void arch_irq_work_raise(void) void timer_interrupt(struct pt_regs * regs) { struct pt_regs *old_regs; - struct decrementer_clock *decrementer = &__get_cpu_var(decrementers); - struct clock_event_device *evt = &decrementer->event; + u64 *next_tb = &__get_cpu_var(decrementers_next_tb); + struct clock_event_device *evt = &__get_cpu_var(decrementers); /* Ensure a positive value is written to the decrementer, or else * some CPUs will continue to take decrementer exceptions. @@ -606,7 +602,7 @@ void timer_interrupt(struct pt_regs * regs) get_lppaca()->int_dword.fields.decr_int = 0; #endif - decrementer->next_tb = ~(u64)0; + *next_tb = ~(u64)0; if (evt->event_handler) evt->event_handler(evt); @@ -872,19 +868,10 @@ static void __init clocksource_init(void) clock->name, clock->mult, clock->shift); } -void decrementer_check_overflow(void) -{ - u64 now = get_tb_or_rtc(); - struct decrementer_clock *decrementer = &__get_cpu_var(decrementers); - - if (now >= decrementer->next_tb) - set_dec(1); -} - static int decrementer_set_next_event(unsigned long evt, struct clock_event_device *dev) { - __get_cpu_var(decrementers).next_tb = get_tb_or_rtc() + evt; + __get_cpu_var(decrementers_next_tb) = get_tb_or_rtc() + evt; set_dec(evt); return 0; } @@ -898,7 +885,7 @@ static void decrementer_set_mode(enum clock_event_mode mode, static void register_decrementer_clockevent(int cpu) { - struct clock_event_device *dec = &per_cpu(decrementers, cpu).event; + struct clock_event_device *dec = &per_cpu(decrementers, cpu); *dec = decrementer_clockevent; dec->cpumask = cpumask_of(cpu); |