From ffe9ee4709cf513fb80e9b7e04d214dd8b76a10d Mon Sep 17 00:00:00 2001 From: Chris Dearman Date: Thu, 24 May 2007 22:24:20 +0100 Subject: [PATCH] [MIPS] Separate performance counter interrupts Support for performance counter overflow interrupt that is on a separate interrupt from the timer. Signed-off-by: Chris Dearman Signed-off-by: Ralf Baechle --- arch/mips/kernel/smp-mt.c | 12 ++-- arch/mips/kernel/time.c | 44 +++++++++---- arch/mips/mips-boards/generic/time.c | 118 +++++++++++++++++++++++++++-------- arch/mips/oprofile/op_model_mipsxx.c | 7 ++- 4 files changed, 135 insertions(+), 46 deletions(-) diff --git a/arch/mips/kernel/smp-mt.c b/arch/mips/kernel/smp-mt.c index 64b62bd..b8fa7dd 100644 --- a/arch/mips/kernel/smp-mt.c +++ b/arch/mips/kernel/smp-mt.c @@ -129,13 +129,13 @@ static irqreturn_t ipi_call_interrupt(int irq, void *dev_id) static struct irqaction irq_resched = { .handler = ipi_resched_interrupt, - .flags = IRQF_DISABLED, + .flags = IRQF_DISABLED|IRQF_PERCPU, .name = "IPI_resched" }; static struct irqaction irq_call = { .handler = ipi_call_interrupt, - .flags = IRQF_DISABLED, + .flags = IRQF_DISABLED|IRQF_PERCPU, .name = "IPI_call" }; @@ -275,10 +275,7 @@ void __init plat_prepare_cpus(unsigned int max_cpus) setup_irq(cpu_ipi_resched_irq, &irq_resched); setup_irq(cpu_ipi_call_irq, &irq_call); - /* need to mark IPI's as IRQ_PER_CPU */ - irq_desc[cpu_ipi_resched_irq].status |= IRQ_PER_CPU; set_irq_handler(cpu_ipi_resched_irq, handle_percpu_irq); - irq_desc[cpu_ipi_call_irq].status |= IRQ_PER_CPU; set_irq_handler(cpu_ipi_call_irq, handle_percpu_irq); } @@ -326,8 +323,11 @@ void prom_boot_secondary(int cpu, struct task_struct *idle) void prom_init_secondary(void) { + /* Enable per-cpu interrupts */ + + /* This is Malta specific: IPI,performance and timer inetrrupts */ write_c0_status((read_c0_status() & ~ST0_IM ) | - (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP7)); + (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP6 | STATUSF_IP7)); } void prom_smp_finish(void) diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c index 751b4a1..7def1ff 100644 --- a/arch/mips/kernel/time.c +++ b/arch/mips/kernel/time.c @@ -199,6 +199,30 @@ int (*perf_irq)(void) = null_perf_irq; EXPORT_SYMBOL(null_perf_irq); EXPORT_SYMBOL(perf_irq); +/* + * Performance counter IRQ or -1 if shared with timer + */ +int mipsxx_perfcount_irq; +EXPORT_SYMBOL(mipsxx_perfcount_irq); + +/* + * Possibly handle a performance counter interrupt. + * Return true if the timer interrupt should not be checked + */ +static inline int handle_perf_irq (int r2) +{ + /* + * The performance counter overflow interrupt may be shared with the + * timer interrupt (mipsxx_perfcount_irq < 0). If it is and a + * performance counter has overflowed (perf_irq() == IRQ_HANDLED) + * and we can't reliably determine if a counter interrupt has also + * happened (!r2) then don't check for a timer interrupt. + */ + return (mipsxx_perfcount_irq < 0) && + perf_irq() == IRQ_HANDLED && + !r2; +} + asmlinkage void ll_timer_interrupt(int irq) { int r2 = cpu_has_mips_r2; @@ -206,19 +230,13 @@ asmlinkage void ll_timer_interrupt(int irq) irq_enter(); kstat_this_cpu.irqs[irq]++; - /* - * Suckage alert: - * Before R2 of the architecture there was no way to see if a - * performance counter interrupt was pending, so we have to run the - * performance counter interrupt handler anyway. - */ - if (!r2 || (read_c0_cause() & (1 << 26))) - if (perf_irq()) - goto out; + if (handle_perf_irq(r2)) + goto out; - /* we keep interrupt disabled all the time */ - if (!r2 || (read_c0_cause() & (1 << 30))) - timer_interrupt(irq, NULL); + if (r2 && ((read_c0_cause() & (1 << 30)) == 0)) + goto out; + + timer_interrupt(irq, NULL); out: irq_exit(); @@ -258,7 +276,7 @@ unsigned int mips_hpt_frequency; static struct irqaction timer_irqaction = { .handler = timer_interrupt, - .flags = IRQF_DISABLED, + .flags = IRQF_DISABLED | IRQF_PERCPU, .name = "timer", }; diff --git a/arch/mips/mips-boards/generic/time.c b/arch/mips/mips-boards/generic/time.c index b41db9e..33432ea 100644 --- a/arch/mips/mips-boards/generic/time.c +++ b/arch/mips/mips-boards/generic/time.c @@ -53,9 +53,8 @@ unsigned long cpu_khz; -#define CPUCTR_IMASKBIT (0x100 << MIPSCPU_INT_CPUCTR) - static int mips_cpu_timer_irq; +extern int mipsxx_perfcount_irq; extern void smtc_timer_broadcast(int); static void mips_timer_dispatch(void) @@ -63,6 +62,11 @@ static void mips_timer_dispatch(void) do_IRQ(mips_cpu_timer_irq); } +static void mips_perf_dispatch(void) +{ + do_IRQ(mipsxx_perfcount_irq); +} + /* * Redeclare until I get around mopping the timer code insanity on MIPS. */ @@ -70,6 +74,24 @@ extern int null_perf_irq(void); extern int (*perf_irq)(void); +/* + * Possibly handle a performance counter interrupt. + * Return true if the timer interrupt should not be checked + */ +static inline int handle_perf_irq (int r2) +{ + /* + * The performance counter overflow interrupt may be shared with the + * timer interrupt (mipsxx_perfcount_irq < 0). If it is and a + * performance counter has overflowed (perf_irq() == IRQ_HANDLED) + * and we can't reliably determine if a counter interrupt has also + * happened (!r2) then don't check for a timer interrupt. + */ + return (mipsxx_perfcount_irq < 0) && + perf_irq() == IRQ_HANDLED && + !r2; +} + irqreturn_t mips_timer_interrupt(int irq, void *dev_id) { int cpu = smp_processor_id(); @@ -92,8 +114,7 @@ irqreturn_t mips_timer_interrupt(int irq, void *dev_id) * We could be here due to timer interrupt, * perf counter overflow, or both. */ - if (read_c0_cause() & (1 << 26)) - perf_irq(); + (void) handle_perf_irq(1); if (read_c0_cause() & (1 << 30)) { /* @@ -115,19 +136,19 @@ irqreturn_t mips_timer_interrupt(int irq, void *dev_id) #else /* CONFIG_MIPS_MT_SMTC */ int r2 = cpu_has_mips_r2; + if (handle_perf_irq(r2)) + goto out; + + if (r2 && ((read_c0_cause() & (1 << 30)) == 0)) + goto out; + if (cpu == 0) { /* * CPU 0 handles the global timer interrupt job and process * accounting resets count/compare registers to trigger next * timer int. */ - if (!r2 || (read_c0_cause() & (1 << 26))) - if (perf_irq()) - goto out; - - /* we keep interrupt disabled all the time */ - if (!r2 || (read_c0_cause() & (1 << 30))) - timer_interrupt(irq, NULL); + timer_interrupt(irq, NULL); } else { /* Everyone else needs to reset the timer int here as ll_local_timer_interrupt doesn't */ @@ -225,35 +246,82 @@ void __init mips_time_init(void) mips_scroll_message(); } -void __init plat_timer_setup(struct irqaction *irq) +irqreturn_t mips_perf_interrupt(int irq, void *dev_id) { + return perf_irq(); +} + +static struct irqaction perf_irqaction = { + .handler = mips_perf_interrupt, + .flags = IRQF_DISABLED | IRQF_PERCPU, + .name = "performance", +}; + +void __init plat_perf_setup(struct irqaction *irq) +{ + int hwint = 0; + mipsxx_perfcount_irq = -1; + #ifdef MSC01E_INT_BASE if (cpu_has_veic) { - set_vi_handler (MSC01E_INT_CPUCTR, mips_timer_dispatch); - mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR; + set_vi_handler (MSC01E_INT_PERFCTR, mips_perf_dispatch); + mipsxx_perfcount_irq = MSC01E_INT_BASE + MSC01E_INT_PERFCTR; } else #endif - { - if (cpu_has_vint) - set_vi_handler (MIPSCPU_INT_CPUCTR, mips_timer_dispatch); - mips_cpu_timer_irq = MIPSCPU_INT_BASE + MIPSCPU_INT_CPUCTR; + if (cpu_has_mips_r2) { + /* + * Read IntCtl.IPPCI to determine the performance + * counter interrupt + */ + hwint = (read_c0_intctl () >> 26) & 7; + if (hwint != MIPSCPU_INT_CPUCTR) { + if (cpu_has_vint) + set_vi_handler (hwint, mips_perf_dispatch); + mipsxx_perfcount_irq = MIPSCPU_INT_BASE + hwint; + } + } + if (mipsxx_perfcount_irq >= 0) { +#ifdef CONFIG_MIPS_MT_SMTC + setup_irq_smtc(mipsxx_perfcount_irq, irq, 0x100 << hwint); +#else + setup_irq(mipsxx_perfcount_irq, irq); +#endif /* CONFIG_MIPS_MT_SMTC */ +#ifdef CONFIG_SMP + set_irq_handler(mipsxx_perfcount_irq, handle_percpu_irq); +#endif } +} +void __init plat_timer_setup(struct irqaction *irq) +{ + int hwint = 0; + if (cpu_has_veic) { + set_vi_handler (MSC01E_INT_CPUCTR, mips_timer_dispatch); + mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR; + } + else { + if (cpu_has_mips_r2) + /* + * Read IntCtl.IPTI to determine the timer interrupt + */ + hwint = (read_c0_intctl () >> 29) & 7; + else + hwint = MIPSCPU_INT_CPUCTR; + if (cpu_has_vint) + set_vi_handler (hwint, mips_timer_dispatch); + mips_cpu_timer_irq = MIPSCPU_INT_BASE + hwint; + } /* we are using the cpu counter for timer interrupts */ irq->handler = mips_timer_interrupt; /* we use our own handler */ #ifdef CONFIG_MIPS_MT_SMTC - setup_irq_smtc(mips_cpu_timer_irq, irq, CPUCTR_IMASKBIT); + setup_irq_smtc(mips_cpu_timer_irq, irq, 0x100 << hwint); #else setup_irq(mips_cpu_timer_irq, irq); #endif /* CONFIG_MIPS_MT_SMTC */ - #ifdef CONFIG_SMP - /* irq_desc(riptor) is a global resource, when the interrupt overlaps - on seperate cpu's the first one tries to handle the second interrupt. - The effect is that the int remains disabled on the second cpu. - Mark the interrupt with IRQ_PER_CPU to avoid any confusion */ - irq_desc[mips_cpu_timer_irq].status |= IRQ_PER_CPU; set_irq_handler(mips_cpu_timer_irq, handle_percpu_irq); #endif + + plat_perf_setup(&perf_irqaction); } diff --git a/arch/mips/oprofile/op_model_mipsxx.c b/arch/mips/oprofile/op_model_mipsxx.c index 4f94fa2..1ea5c9c 100644 --- a/arch/mips/oprofile/op_model_mipsxx.c +++ b/arch/mips/oprofile/op_model_mipsxx.c @@ -177,7 +177,10 @@ static int mipsxx_perfcount_handler(void) unsigned int counters = op_model_mipsxx_ops.num_counters; unsigned int control; unsigned int counter; - int handled = 0; + int handled = IRQ_NONE; + + if (cpu_has_mips_r2 && !(read_c0_cause() & (1 << 26))) + return handled; switch (counters) { #define HANDLE_COUNTER(n) \ @@ -188,7 +191,7 @@ static int mipsxx_perfcount_handler(void) (counter & M_COUNTER_OVERFLOW)) { \ oprofile_add_sample(get_irq_regs(), n); \ w_c0_perfcntr ## n(reg.counter[n]); \ - handled = 1; \ + handled = IRQ_HANDLED; \ } HANDLE_COUNTER(3) HANDLE_COUNTER(2) -- 2.7.4