diff options
Diffstat (limited to 'arch/mips/kernel/cevt-r4k.c')
| -rw-r--r-- | arch/mips/kernel/cevt-r4k.c | 80 |
1 files changed, 37 insertions, 43 deletions
diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c index 2f4d7a99bcc..bc127e22fda 100644 --- a/arch/mips/kernel/cevt-r4k.c +++ b/arch/mips/kernel/cevt-r4k.c @@ -12,19 +12,12 @@ #include <linux/smp.h> #include <linux/irq.h> -#include <asm/smtc_ipi.h> #include <asm/time.h> #include <asm/cevt-r4k.h> - -/* - * The SMTC Kernel for the 34K, 1004K, et. al. replaces several - * of these routines with SMTC-specific variants. - */ - -#ifndef CONFIG_MIPS_MT_SMTC +#include <asm/gic.h> static int mips_next_event(unsigned long delta, - struct clock_event_device *evt) + struct clock_event_device *evt) { unsigned int cnt; int res; @@ -32,12 +25,10 @@ static int mips_next_event(unsigned long delta, cnt = read_c0_count(); cnt += delta; write_c0_compare(cnt); - res = ((int)(read_c0_count() - cnt) > 0) ? -ETIME : 0; + res = ((int)(read_c0_count() - cnt) >= 0) ? -ETIME : 0; return res; } -#endif /* CONFIG_MIPS_MT_SMTC */ - void mips_set_clock_mode(enum clock_event_mode mode, struct clock_event_device *evt) { @@ -47,8 +38,6 @@ void mips_set_clock_mode(enum clock_event_mode mode, DEFINE_PER_CPU(struct clock_event_device, mips_clockevent_device); int cp0_timer_irq_installed; -#ifndef CONFIG_MIPS_MT_SMTC - irqreturn_t c0_compare_interrupt(int irq, void *dev_id) { const int r2 = cpu_has_mips_r2; @@ -65,7 +54,7 @@ irqreturn_t c0_compare_interrupt(int irq, void *dev_id) goto out; /* - * The same applies to performance counter interrupts. But with the + * The same applies to performance counter interrupts. But with the * above we now know that the reason we got here must be a timer * interrupt. Being the paranoiacs we are we check anyway. */ @@ -80,11 +69,9 @@ out: return IRQ_HANDLED; } -#endif /* Not CONFIG_MIPS_MT_SMTC */ - struct irqaction c0_compare_irqaction = { .handler = c0_compare_interrupt, - .flags = IRQF_DISABLED | IRQF_PERCPU | IRQF_TIMER, + .flags = IRQF_PERCPU | IRQF_TIMER, .name = "timer", }; @@ -98,36 +85,39 @@ void mips_event_handler(struct clock_event_device *dev) */ static int c0_compare_int_pending(void) { +#ifdef CONFIG_IRQ_GIC + if (cpu_has_veic) + return gic_get_timer_pending(); +#endif return (read_c0_cause() >> cp0_compare_irq_shift) & (1ul << CAUSEB_IP); } /* * Compare interrupt can be routed and latched outside the core, - * so a single execution hazard barrier may not be enough to give - * it time to clear as seen in the Cause register. 4 time the - * pipeline depth seems reasonably conservative, and empirically - * works better in configurations with high CPU/bus clock ratios. + * so wait up to worst case number of cycle counter ticks for timer interrupt + * changes to propagate to the cause register. */ - -#define compare_change_hazard() \ - do { \ - irq_disable_hazard(); \ - irq_disable_hazard(); \ - irq_disable_hazard(); \ - irq_disable_hazard(); \ - } while (0) +#define COMPARE_INT_SEEN_TICKS 50 int c0_compare_int_usable(void) { unsigned int delta; unsigned int cnt; +#ifdef CONFIG_KVM_GUEST + return 1; +#endif + /* - * IP7 already pending? Try to clear it by acking the timer. + * IP7 already pending? Try to clear it by acking the timer. */ if (c0_compare_int_pending()) { - write_c0_compare(read_c0_count()); - compare_change_hazard(); + cnt = read_c0_count(); + write_c0_compare(cnt); + back_to_back_c0_hazard(); + while (read_c0_count() < (cnt + COMPARE_INT_SEEN_TICKS)) + if (!c0_compare_int_pending()) + break; if (c0_compare_int_pending()) return 0; } @@ -136,7 +126,7 @@ int c0_compare_int_usable(void) cnt = read_c0_count(); cnt += delta; write_c0_compare(cnt); - compare_change_hazard(); + back_to_back_c0_hazard(); if ((int)(read_c0_count() - cnt) < 0) break; /* increase delta if the timer was already expired */ @@ -145,12 +135,17 @@ int c0_compare_int_usable(void) while ((int)(read_c0_count() - cnt) <= 0) ; /* Wait for expiry */ - compare_change_hazard(); + while (read_c0_count() < (cnt + COMPARE_INT_SEEN_TICKS)) + if (c0_compare_int_pending()) + break; if (!c0_compare_int_pending()) return 0; - - write_c0_compare(read_c0_count()); - compare_change_hazard(); + cnt = read_c0_count(); + write_c0_compare(cnt); + back_to_back_c0_hazard(); + while (read_c0_count() < (cnt + COMPARE_INT_SEEN_TICKS)) + if (!c0_compare_int_pending()) + break; if (c0_compare_int_pending()) return 0; @@ -160,9 +155,7 @@ int c0_compare_int_usable(void) return 1; } -#ifndef CONFIG_MIPS_MT_SMTC - -int __cpuinit r4k_clockevent_init(void) +int r4k_clockevent_init(void) { unsigned int cpu = smp_processor_id(); struct clock_event_device *cd; @@ -186,7 +179,9 @@ int __cpuinit r4k_clockevent_init(void) cd = &per_cpu(mips_clockevent_device, cpu); cd->name = "MIPS"; - cd->features = CLOCK_EVT_FEAT_ONESHOT; + cd->features = CLOCK_EVT_FEAT_ONESHOT | + CLOCK_EVT_FEAT_C3STOP | + CLOCK_EVT_FEAT_PERCPU; clockevent_set_clock(cd, mips_hpt_frequency); @@ -213,4 +208,3 @@ int __cpuinit r4k_clockevent_init(void) return 0; } -#endif /* Not CONFIG_MIPS_MT_SMTC */ |