From 1ffbc51a0d00e52983c70aa7c8dbc7b621d6287d Mon Sep 17 00:00:00 2001 From: Andreas Larsson Date: Mon, 10 Jun 2013 08:53:28 +0200 Subject: [PATCH] sparc32, leon: Remove separate "ticker" timer for SMP This reduces the need from two timers to one timer. Moreover, without this patch, when the "ticker" timer triggers timer_cs_read via tick_periodic it reads the value of the usual timer it can get an wrapped timer value without timer_cs_internal_counter having been updated leading to the clock going backwards. This effectively hangs one cpu that gets stuck in update_wall_time with an offset slightly smaller than 0xffffffffffffffff. Signed-off-by: Andreas Larsson Signed-off-by: David S. Miller --- arch/sparc/include/asm/leon.h | 2 +- arch/sparc/include/asm/leon_amba.h | 1 + arch/sparc/kernel/leon_kernel.c | 54 ++++++++++-------------------- 3 files changed, 19 insertions(+), 38 deletions(-) diff --git a/arch/sparc/include/asm/leon.h b/arch/sparc/include/asm/leon.h index 15a716934e4d..b836e9297f2a 100644 --- a/arch/sparc/include/asm/leon.h +++ b/arch/sparc/include/asm/leon.h @@ -135,7 +135,7 @@ static inline int sparc_leon3_cpuid(void) #ifdef CONFIG_SMP # define LEON3_IRQ_IPI_DEFAULT 13 -# define LEON3_IRQ_TICKER (leon3_ticker_irq) +# define LEON3_IRQ_TICKER (leon3_gptimer_irq) # define LEON3_IRQ_CROSS_CALL 15 #endif diff --git a/arch/sparc/include/asm/leon_amba.h b/arch/sparc/include/asm/leon_amba.h index f3034eddf468..24ec48c3ff90 100644 --- a/arch/sparc/include/asm/leon_amba.h +++ b/arch/sparc/include/asm/leon_amba.h @@ -47,6 +47,7 @@ struct amba_prom_registers { #define LEON3_GPTIMER_LD 4 #define LEON3_GPTIMER_IRQEN 8 #define LEON3_GPTIMER_SEPIRQ 8 +#define LEON3_GPTIMER_TIMERS 0x7 #define LEON23_REG_TIMER_CONTROL_EN 0x00000001 /* 1 = enable counting */ /* 0 = hold scalar and counter */ diff --git a/arch/sparc/kernel/leon_kernel.c b/arch/sparc/kernel/leon_kernel.c index 7c0231dabe44..b7c68976cbc7 100644 --- a/arch/sparc/kernel/leon_kernel.c +++ b/arch/sparc/kernel/leon_kernel.c @@ -38,7 +38,6 @@ static DEFINE_SPINLOCK(leon_irq_lock); unsigned long leon3_gptimer_irq; /* interrupt controller irq number */ unsigned long leon3_gptimer_idx; /* Timer Index (0..6) within Timer Core */ -int leon3_ticker_irq; /* Timer ticker IRQ */ unsigned int sparc_leon_eirq; #define LEON_IMASK(cpu) (&leon3_irqctrl_regs->mask[cpu]) #define LEON_IACK (&leon3_irqctrl_regs->iclear) @@ -278,6 +277,9 @@ irqreturn_t leon_percpu_timer_ce_interrupt(int irq, void *unused) leon_clear_profile_irq(cpu); + if (cpu == boot_cpu_id) + timer_interrupt(irq, NULL); + ce = &per_cpu(sparc32_clockevent, cpu); irq_enter(); @@ -299,6 +301,7 @@ void __init leon_init_timers(void) int icsel; int ampopts; int err; + u32 config; sparc_config.get_cycles_offset = leon_cycles_offset; sparc_config.cs_period = 1000000 / HZ; @@ -377,23 +380,6 @@ void __init leon_init_timers(void) LEON3_BYPASS_STORE_PA( &leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl, 0); -#ifdef CONFIG_SMP - leon3_ticker_irq = leon3_gptimer_irq + 1 + leon3_gptimer_idx; - - if (!(LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->config) & - (1<e[leon3_gptimer_idx+1].val, - 0); - LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx+1].rld, - (((1000000/HZ) - 1))); - LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx+1].ctrl, - 0); -#endif - /* * The IRQ controller may (if implemented) consist of multiple * IRQ controllers, each mapped on a 4Kb boundary. @@ -416,13 +402,6 @@ void __init leon_init_timers(void) if (eirq != 0) leon_eirq_setup(eirq); - irq = _leon_build_device_irq(NULL, leon3_gptimer_irq+leon3_gptimer_idx); - err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL); - if (err) { - printk(KERN_ERR "unable to attach timer IRQ%d\n", irq); - prom_halt(); - } - #ifdef CONFIG_SMP { unsigned long flags; @@ -439,30 +418,31 @@ void __init leon_init_timers(void) } #endif - LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl, - LEON3_GPTIMER_EN | - LEON3_GPTIMER_RL | - LEON3_GPTIMER_LD | - LEON3_GPTIMER_IRQEN); + config = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->config); + if (config & (1 << LEON3_GPTIMER_SEPIRQ)) + leon3_gptimer_irq += leon3_gptimer_idx; + else if ((config & LEON3_GPTIMER_TIMERS) > 1) + pr_warn("GPTIMER uses shared irqs, using other timers of the same core will fail.\n"); #ifdef CONFIG_SMP /* Install per-cpu IRQ handler for broadcasted ticker */ - irq = leon_build_device_irq(leon3_ticker_irq, handle_percpu_irq, + irq = leon_build_device_irq(leon3_gptimer_irq, handle_percpu_irq, "per-cpu", 0); err = request_irq(irq, leon_percpu_timer_ce_interrupt, - IRQF_PERCPU | IRQF_TIMER, "ticker", - NULL); + IRQF_PERCPU | IRQF_TIMER, "timer", NULL); +#else + irq = _leon_build_device_irq(NULL, leon3_gptimer_irq); + err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL); +#endif if (err) { - printk(KERN_ERR "unable to attach ticker IRQ%d\n", irq); + pr_err("Unable to attach timer IRQ%d\n", irq); prom_halt(); } - - LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx+1].ctrl, + LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl, LEON3_GPTIMER_EN | LEON3_GPTIMER_RL | LEON3_GPTIMER_LD | LEON3_GPTIMER_IRQEN); -#endif return; bad: printk(KERN_ERR "No Timer/irqctrl found\n"); -- GitLab