Re: [PATCH 1/1] sparc32,leon: GENERIC_CLOCKEVENTS support for SPARC-LEON

[Kirill Tkhai <tkhai@yandex.ru>]

Thanks a lot, Konrad!

On Thu, 2012-03-15 at 11:33 +0100, Konrad Eisele wrote:
> Add GENERIC_CLOCKEVENTS support for SPARC-LEON.
> 
> The late_time_init initialization has been moved to
> enable overriding it for SPARC-LEON.
> 
> Signed-off-by: Konrad Eisele <konrad@gaisler.com>
> ---
>  arch/sparc/include/asm/leon.h   |    3 +-
>  arch/sparc/kernel/leon_kernel.c |  189 ++++++++++++++++++++++++++++++++++++++-
>  arch/sparc/kernel/leon_smp.c    |   34 +------
>  arch/sparc/kernel/time_32.c     |    4 +-
>  4 files changed, 193 insertions(+), 37 deletions(-)
> 
> diff --git a/arch/sparc/include/asm/leon.h b/arch/sparc/include/asm/leon.h
> index a4e457f..9b9b24f 100644
> --- a/arch/sparc/include/asm/leon.h
> +++ b/arch/sparc/include/asm/leon.h
> @@ -323,7 +323,7 @@ extern void leon_update_virq_handling(unsigned int virq,
>  			      const char *name, int do_ack);
>  extern void leon_clear_clock_irq(void);
>  extern void leon_load_profile_irq(int cpu, unsigned int limit);
> -extern void leon_init_timers(irq_handler_t counter_fn);
> +extern void leon_init_timers(void);
>  extern void leon_clear_clock_irq(void);
>  extern void leon_load_profile_irq(int cpu, unsigned int limit);
>  extern void leon_trans_init(struct device_node *dp);
> @@ -351,6 +351,7 @@ extern void init_IRQ(void);
>  extern void cpu_panic(void);
>  extern int __leon_processor_id(void);
>  void leon_enable_irq_cpu(unsigned int irq_nr, unsigned int cpu);
> +extern void leon_register_percpu_ce(int cpu);
>  extern irqreturn_t leon_percpu_timer_interrupt(int irq, void *unused);
>  
>  extern unsigned int real_irq_entry[];
> diff --git a/arch/sparc/kernel/leon_kernel.c b/arch/sparc/kernel/leon_kernel.c
> index a19c8a0..62afe3f 100644
> --- a/arch/sparc/kernel/leon_kernel.c
> +++ b/arch/sparc/kernel/leon_kernel.c
> @@ -10,6 +10,8 @@
>  #include <linux/of_platform.h>
>  #include <linux/interrupt.h>
>  #include <linux/of_device.h>
> +#include <linux/clocksource.h>
> +#include <linux/clockchips.h>
>  
>  #include <asm/oplib.h>
>  #include <asm/timer.h>
> @@ -27,12 +29,18 @@
>  struct leon3_irqctrl_regs_map *leon3_irqctrl_regs; /* interrupt controller base address */
>  struct leon3_gptimer_regs_map *leon3_gptimer_regs; /* timer controller base address */
>  
> +static __cacheline_aligned_in_smp DEFINE_SEQLOCK(leon_timer_cs_lock);
> +static __volatile__ u64 leon_timer_cs_internal_counter = 0;
>  int leondebug_irq_disable;
>  int leon_debug_irqout;
>  static int dummy_master_l10_counter;
>  unsigned long amba_system_id;
>  static DEFINE_SPINLOCK(leon_irq_lock);
>  
> +static char leon_timer_cs_enabled = 0;
> +#ifndef CONFIG_SMP
> +static char leon_timer_ce_enabled = 0;
> +#endif
>  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 */
> @@ -250,7 +258,177 @@ void leon_update_virq_handling(unsigned int virq,
>  	irq_set_chip_data(virq, (void *)mask);
>  }
>  
> -void __init leon_init_timers(irq_handler_t counter_fn)
> +static u32 leon_cycles_offset(void)
> +{
> +	u32 rld, val, off;
> +	rld = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld);
> +	val = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val);
> +	off = rld - val;
> +	return rld - val;
> +}
> +
> +static cycle_t leon_timer_cs_read(struct clocksource *cs)
> +{
> +	unsigned int seq, offset;
> +	u64 cycles;
> +
> +	do {
> +		seq = read_seqbegin(&leon_timer_cs_lock);
> +		cycles = leon_timer_cs_internal_counter;
> +		offset = leon_cycles_offset();
> +	} while (read_seqretry(&leon_timer_cs_lock, seq));
> +
> +	cycles *= timer_cs_period;
> +	cycles += offset;
> +	return cycles;
> +}
> +
> +static struct clocksource leon_timer_cs = {
> +	.name	= "grtimer-cs",
> +	.rating	= 200,
> +	.read	= leon_timer_cs_read,
> +	.mask	= CLOCKSOURCE_MASK(32),
> +	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
> +};
> +
> +#ifndef CONFIG_SMP
> +
> +static void leon_timer_ce_set_mode(enum clock_event_mode mode,
> +			      struct clock_event_device *evt)
> +{
> +	switch (mode) {
> +		case CLOCK_EVT_MODE_PERIODIC:
> +		case CLOCK_EVT_MODE_RESUME:
> +			leon_timer_ce_enabled = 1;
> +			break;
> +		case CLOCK_EVT_MODE_SHUTDOWN:
> +			leon_timer_ce_enabled = 0;
> +			break;
> +		default:
> +			break;
> +	}
> +	smp_mb();
> +}
> +
> +static struct clock_event_device leon_timer_ce = {
> +	.name	  = "grtimer-ce",
> +	.rating	  = 100,
> +	.features = CLOCK_EVT_FEAT_PERIODIC,
> +	.set_mode = leon_timer_ce_set_mode,
> +	.shift    = 32
> +};
> +
> +#endif /* !CONFIG_SMP */
> +
> +static void __init leon_late_time_init(void)
> +{
> +	leon_timer_cs_enabled = 1;
> +
> +	clocksource_register_hz(&leon_timer_cs, 1000000);
> +
> +#ifdef CONFIG_SMP
> +	leon_register_percpu_ce(smp_processor_id());
> +#else
> +	BUG_ON(smp_processor_id() != boot_cpu_id);
> +	leon_timer_ce.cpumask = cpu_possible_mask;
> +	leon_timer_ce.mult    = div_sc(1000000, NSEC_PER_SEC,
> +				       leon_timer_ce.shift);
> +	clockevents_register_device(&leon_timer_ce);
> +#endif /* CONFIG_SMP */
> +}
> +
> +/* clocksource irq, non-smp clockevent */
> +irqreturn_t notrace leon_timer_interrupt(int dummy, void *dev_id)
> +{
> +	if (leon_timer_cs_enabled) {
> +		write_seqlock(&leon_timer_cs_lock);
> +		leon_timer_cs_internal_counter++;
> +		write_sequnlock(&leon_timer_cs_lock);
> +	}
> +#ifndef CONFIG_SMP
> +	if (leon_timer_ce_enabled) {
> +		if (leon_timer_ce.event_handler)
> +			leon_timer_ce.event_handler(&leon_timer_ce);
> +	}
> +	
> +#endif
> +	return IRQ_HANDLED;
> +}
> +
> +#ifdef CONFIG_SMP
> +
> +/* smp clockevent irq */
> +irqreturn_t leon_percpu_timer_ce_interrupt(int irq, void *unused)
> +{
> +	struct clock_event_device *ce;
> +	int cpu = smp_processor_id();
> +
> +	leon_clear_profile_irq(cpu);
> +
> +	ce = &per_cpu(sparc32_clockevent, cpu);
> +
> +	irq_enter();
> +	if (ce->event_handler)
> +		ce->event_handler(ce);
> +	irq_exit();
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static void leon_percpu_ce_setup(enum clock_event_mode mode,
> +			struct clock_event_device *evt)
> +{
> +	int cpu = __first_cpu(evt->cpumask);
> +
> +	switch (mode) {
> +		case CLOCK_EVT_MODE_PERIODIC:
> +			leon_load_profile_irq(cpu, (1000000 / HZ));
> +			break;
> +		case CLOCK_EVT_MODE_ONESHOT:
> +		case CLOCK_EVT_MODE_SHUTDOWN:
> +		case CLOCK_EVT_MODE_UNUSED:
> +			leon_load_profile_irq(cpu, 0);
> +			break;
> +		default:
> +			break;
> +	}
> +}
> +
> +static int leon_percpu_ce_set_next_event(unsigned long delta,
> +				    struct clock_event_device *evt)
> +{
> +	int cpu = __first_cpu(evt->cpumask);
> +	unsigned int next = (unsigned int)delta;
> +	leon_load_profile_irq(cpu, next);
> +	return 0;
> +}
> +
> +void leon_register_percpu_ce(int cpu)
> +{
> +	struct clock_event_device *ce = &per_cpu(sparc32_clockevent, cpu);
> +	unsigned int features = CLOCK_EVT_FEAT_PERIODIC;
> +
> +	if (sparc_irq_config.features & FEAT_L14_OS)
> +		features |= CLOCK_EVT_FEAT_ONESHOT;
> +
> +	ce->name		= "grtimer-ce";
> +	ce->rating		= 200;
> +	ce->features		= features;
> +	ce->set_mode		= leon_percpu_ce_setup;
> +	ce->set_next_event	= leon_percpu_ce_set_next_event;
> +	ce->cpumask		= cpumask_of(cpu);
> +	ce->shift		= 32;
> +	ce->mult		= div_sc(1000000, NSEC_PER_SEC,
> +					 ce->shift);
> +	ce->max_delta_ns	= clockevent_delta2ns(1000000, ce);
> +	ce->min_delta_ns	= clockevent_delta2ns(100, ce);
> +
> +	clockevents_register_device(ce);
> +}
> +
> +#endif /* CONFIG_SMP */
> +
> +void __init leon_init_timers(void)
>  {
>  	int irq, eirq;
>  	struct device_node *rootnp, *np, *nnp;
> @@ -260,6 +438,10 @@ void __init leon_init_timers(irq_handler_t counter_fn)
>  	int ampopts;
>  	int err;
>  
> +	late_time_init = leon_late_time_init;
> +	get_cycles_offset = leon_cycles_offset;
> +	timer_cs_period = 1000000 / HZ;
> +
>  	leondebug_irq_disable = 0;
>  	leon_debug_irqout = 0;
>  	master_l10_counter = (unsigned int *)&dummy_master_l10_counter;
> @@ -369,7 +551,7 @@ void __init leon_init_timers(irq_handler_t counter_fn)
>  		leon_eirq_setup(eirq);
>  
>  	irq = _leon_build_device_irq(NULL, leon3_gptimer_irq+leon3_gptimer_idx);
> -	err = request_irq(irq, counter_fn, IRQF_TIMER, "timer", NULL);
> +	err = request_irq(irq, leon_timer_interrupt, IRQF_TIMER, "timer", NULL);
>  	if (err) {
>  		printk(KERN_ERR "unable to attach timer IRQ%d\n", irq);
>  		prom_halt();
> @@ -401,7 +583,7 @@ void __init leon_init_timers(irq_handler_t counter_fn)
>  	/* Install per-cpu IRQ handler for broadcasted ticker */
>  	irq = leon_build_device_irq(leon3_ticker_irq, handle_percpu_irq,
>  				    "per-cpu", 0);
> -	err = request_irq(irq, leon_percpu_timer_interrupt,
> +	err = request_irq(irq, leon_percpu_timer_ce_interrupt,
>  			  IRQF_PERCPU | IRQF_TIMER, "ticker",
>  			  NULL);
>  	if (err) {
> @@ -428,7 +610,6 @@ void leon_clear_clock_irq(void)
>  
>  void leon_load_profile_irq(int cpu, unsigned int limit)
>  {
> -	BUG();
>  }
>  
>  void __init leon_trans_init(struct device_node *dp)
> diff --git a/arch/sparc/kernel/leon_smp.c b/arch/sparc/kernel/leon_smp.c
> index 1210fde..0bda9b1 100644
> --- a/arch/sparc/kernel/leon_smp.c
> +++ b/arch/sparc/kernel/leon_smp.c
> @@ -23,6 +23,8 @@
>  #include <linux/pm.h>
>  #include <linux/delay.h>
>  #include <linux/gfp.h>
> +#include <linux/cpu.h>
> +#include <linux/clockchips.h>
>  
>  #include <asm/cacheflush.h>
>  #include <asm/tlbflush.h>
> @@ -42,6 +44,7 @@
>  #include <asm/asi.h>
>  #include <asm/leon.h>
>  #include <asm/leon_amba.h>
> +#include <asm/timer.h>
>  
>  #include "kernel.h"
>  
> @@ -68,8 +71,6 @@ static inline unsigned long do_swap(volatile unsigned long *ptr,
>  	return val;
>  }
>  
> -static void smp_setup_percpu_timer(void);
> -
>  void __cpuinit leon_callin(void)
>  {
>  	int cpuid = hard_smpleon_processor_id();
> @@ -79,7 +80,7 @@ void __cpuinit leon_callin(void)
>  	leon_configure_cache_smp();
>  
>  	/* Get our local ticker going. */
> -	smp_setup_percpu_timer();
> +	leon_register_percpu_ce(cpuid);
>  
>  	calibrate_delay();
>  	smp_store_cpu_info(cpuid);
> @@ -196,7 +197,6 @@ void __init leon_boot_cpus(void)
>  	leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
>  
>  	leon_configure_cache_smp();
> -	smp_setup_percpu_timer();
>  	local_flush_cache_all();
>  
>  }
> @@ -489,32 +489,6 @@ void leon_cross_call_irq(void)
>  	ccall_info.processors_out[i] = 1;
>  }
>  
> -irqreturn_t leon_percpu_timer_interrupt(int irq, void *unused)
> -{
> -	int cpu = smp_processor_id();
> -
> -	leon_clear_profile_irq(cpu);
> -
> -	profile_tick(CPU_PROFILING);
> -
> -	if (!--prof_counter(cpu)) {
> -		int user = user_mode(get_irq_regs());
> -
> -		update_process_times(user);
> -
> -		prof_counter(cpu) = prof_multiplier(cpu);
> -	}
> -
> -	return IRQ_HANDLED;
> -}
> -
> -static void __init smp_setup_percpu_timer(void)
> -{
> -	int cpu = smp_processor_id();
> -
> -	prof_counter(cpu) = prof_multiplier(cpu) = 1;
> -}
> -
>  void __init leon_blackbox_id(unsigned *addr)
>  {
>  	int rd = *addr & 0x3e000000;
> diff --git a/arch/sparc/kernel/time_32.c b/arch/sparc/kernel/time_32.c
> index fc66bff..7427a49 100644
> --- a/arch/sparc/kernel/time_32.c
> +++ b/arch/sparc/kernel/time_32.c
> @@ -367,12 +367,12 @@ void __init time_init(void)
>  
>  	sparc_irq_config.features = 0;
>  
> +	late_time_init = sparc32_late_time_init;
> +
>  	if (pcic_present())
>  		pci_time_init();
>  	else
>  		sbus_time_init();
> -
> -	late_time_init = sparc32_late_time_init;
>  }
>  
>