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[ARM] smp: move core localtimer support out of platform specific files
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Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Russell King authored and Russell King committed May 17, 2009
1 parent ee348d5 commit bc28248
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Showing 6 changed files with 121 additions and 111 deletions.
1 change: 1 addition & 0 deletions arch/arm/Kconfig
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Expand Up @@ -859,6 +859,7 @@ source "kernel/time/Kconfig"
config SMP
bool "Symmetric Multi-Processing (EXPERIMENTAL)"
depends on EXPERIMENTAL && (REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP)
depends on GENERIC_CLOCKEVENTS
select USE_GENERIC_SMP_HELPERS
help
This enables support for systems with more than one CPU. If you have
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51 changes: 51 additions & 0 deletions arch/arm/include/asm/localtimer.h
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@@ -0,0 +1,51 @@
/*
* arch/arm/include/asm/localtimer.h
*
* Copyright (C) 2004-2005 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_ARM_LOCALTIMER_H
#define __ASM_ARM_LOCALTIMER_H

struct clock_event_device;

/*
* Setup a per-cpu timer, whether it be a local timer or dummy broadcast
*/
void percpu_timer_setup(void);

/*
* Called from assembly, this is the local timer IRQ handler
*/
asmlinkage void do_local_timer(struct pt_regs *);


#ifdef CONFIG_LOCAL_TIMERS
/*
* Platform provides this to acknowledge a local timer IRQ.
* Returns true if the local timer IRQ is to be processed.
*/
int local_timer_ack(void);

/*
* Stop a local timer interrupt.
*/
void local_timer_stop(void);

/*
* Setup a local timer interrupt for a CPU.
*/
void local_timer_setup(struct clock_event_device *);

#else

static inline void local_timer_stop(void)
{
}

#endif

#endif
40 changes: 0 additions & 40 deletions arch/arm/include/asm/smp.h
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Expand Up @@ -55,11 +55,6 @@ extern void smp_store_cpu_info(unsigned int cpuid);
*/
extern void smp_cross_call(const struct cpumask *mask);

/*
* Broadcast a clock event to other CPUs.
*/
extern void smp_timer_broadcast(const struct cpumask *mask);

/*
* Boot a secondary CPU, and assign it the specified idle task.
* This also gives us the initial stack to use for this CPU.
Expand Down Expand Up @@ -100,44 +95,9 @@ extern void arch_send_call_function_single_ipi(int cpu);
extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
#define arch_send_call_function_ipi_mask arch_send_call_function_ipi_mask

/*
* Local timer interrupt handling function (can be IPI'ed).
*/
extern void local_timer_interrupt(void);

#ifdef CONFIG_LOCAL_TIMERS

/*
* Stop a local timer interrupt.
*/
extern void local_timer_stop(void);

/*
* Platform provides this to acknowledge a local timer IRQ
*/
extern int local_timer_ack(void);

#else

static inline void local_timer_stop(void)
{
}

#endif

/*
* Setup a local timer interrupt for a CPU.
*/
extern void local_timer_setup(void);

/*
* show local interrupt info
*/
extern void show_local_irqs(struct seq_file *);

/*
* Called from assembly, this is the local timer IRQ handler
*/
asmlinkage void do_local_timer(struct pt_regs *);

#endif /* ifndef __ASM_ARM_SMP_H */
56 changes: 48 additions & 8 deletions arch/arm/kernel/smp.c
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Expand Up @@ -22,6 +22,8 @@
#include <linux/smp.h>
#include <linux/seq_file.h>
#include <linux/irq.h>
#include <linux/percpu.h>
#include <linux/clockchips.h>

#include <asm/atomic.h>
#include <asm/cacheflush.h>
Expand All @@ -32,6 +34,7 @@
#include <asm/processor.h>
#include <asm/tlbflush.h>
#include <asm/ptrace.h>
#include <asm/localtimer.h>

/*
* as from 2.5, kernels no longer have an init_tasks structure
Expand Down Expand Up @@ -274,9 +277,9 @@ asmlinkage void __cpuinit secondary_start_kernel(void)
local_fiq_enable();

/*
* Setup local timer for this CPU.
* Setup the percpu timer for this CPU.
*/
local_timer_setup();
percpu_timer_setup();

calibrate_delay();

Expand Down Expand Up @@ -383,10 +386,16 @@ void show_local_irqs(struct seq_file *p)
seq_putc(p, '\n');
}

/*
* Timer (local or broadcast) support
*/
static DEFINE_PER_CPU(struct clock_event_device, percpu_clockevent);

static void ipi_timer(void)
{
struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent);
irq_enter();
local_timer_interrupt();
evt->event_handler(evt);
irq_exit();
}

Expand All @@ -405,6 +414,42 @@ asmlinkage void __exception do_local_timer(struct pt_regs *regs)
}
#endif

#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
static void smp_timer_broadcast(const struct cpumask *mask)
{
send_ipi_message(mask, IPI_TIMER);
}

static void broadcast_timer_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
}

static void local_timer_setup(struct clock_event_device *evt)
{
evt->name = "dummy_timer";
evt->features = CLOCK_EVT_FEAT_ONESHOT |
CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_DUMMY;
evt->rating = 400;
evt->mult = 1;
evt->set_mode = broadcast_timer_set_mode;
evt->broadcast = smp_timer_broadcast;

clockevents_register_device(evt);
}
#endif

void __cpuinit percpu_timer_setup(void)
{
unsigned int cpu = smp_processor_id();
struct clock_event_device *evt = &per_cpu(percpu_clockevent, cpu);

evt->cpumask = cpumask_of(cpu);

local_timer_setup(evt);
}

static DEFINE_SPINLOCK(stop_lock);

/*
Expand Down Expand Up @@ -501,11 +546,6 @@ void smp_send_reschedule(int cpu)
send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
}

void smp_timer_broadcast(const struct cpumask *mask)
{
send_ipi_message(mask, IPI_TIMER);
}

void smp_send_stop(void)
{
cpumask_t mask = cpu_online_map;
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70 changes: 14 additions & 56 deletions arch/arm/mach-realview/localtimer.c
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Original file line number Diff line number Diff line change
Expand Up @@ -11,10 +11,8 @@
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/jiffies.h>
#include <linux/percpu.h>
#include <linux/clockchips.h>
#include <linux/irq.h>
#include <linux/io.h>
Expand All @@ -24,18 +22,6 @@
#include <mach/hardware.h>
#include <asm/irq.h>

static DEFINE_PER_CPU(struct clock_event_device, local_clockevent);

/*
* Used on SMP for either the local timer or IPI_TIMER
*/
void local_timer_interrupt(void)
{
struct clock_event_device *clk = &__get_cpu_var(local_clockevent);

clk->event_handler(clk);
}

#ifdef CONFIG_LOCAL_TIMERS

/* set up by the platform code */
Expand All @@ -44,7 +30,7 @@ void __iomem *twd_base;
static unsigned long mpcore_timer_rate;

static void local_timer_set_mode(enum clock_event_mode mode,
struct clock_event_device *clk)
struct clock_event_device *evt)
{
unsigned long ctrl;

Expand Down Expand Up @@ -140,32 +126,29 @@ static void __cpuinit twd_calibrate_rate(void)
/*
* Setup the local clock events for a CPU.
*/
void __cpuinit local_timer_setup(void)
void __cpuinit local_timer_setup(struct clock_event_device *evt)
{
unsigned int cpu = smp_processor_id();
struct clock_event_device *clk = &per_cpu(local_clockevent, cpu);
unsigned long flags;

twd_calibrate_rate();

clk->name = "local_timer";
clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
clk->rating = 350;
clk->set_mode = local_timer_set_mode;
clk->set_next_event = local_timer_set_next_event;
clk->irq = IRQ_LOCALTIMER;
clk->cpumask = cpumask_of(cpu);
clk->shift = 20;
clk->mult = div_sc(mpcore_timer_rate, NSEC_PER_SEC, clk->shift);
clk->max_delta_ns = clockevent_delta2ns(0xffffffff, clk);
clk->min_delta_ns = clockevent_delta2ns(0xf, clk);
evt->name = "local_timer";
evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
evt->rating = 350;
evt->set_mode = local_timer_set_mode;
evt->set_next_event = local_timer_set_next_event;
evt->irq = IRQ_LOCALTIMER;
evt->shift = 20;
evt->mult = div_sc(mpcore_timer_rate, NSEC_PER_SEC, evt->shift);
evt->max_delta_ns = clockevent_delta2ns(0xffffffff, evt);
evt->min_delta_ns = clockevent_delta2ns(0xf, evt);

/* Make sure our local interrupt controller has this enabled */
local_irq_save(flags);
get_irq_chip(IRQ_LOCALTIMER)->unmask(IRQ_LOCALTIMER);
local_irq_restore(flags);

clockevents_register_device(clk);
clockevents_register_device(evt);
}

/*
Expand All @@ -176,29 +159,4 @@ void __cpuexit local_timer_stop(void)
__raw_writel(0, twd_base + TWD_TIMER_CONTROL);
}

#else /* CONFIG_LOCAL_TIMERS */

static void dummy_timer_set_mode(enum clock_event_mode mode,
struct clock_event_device *clk)
{
}

void __cpuinit local_timer_setup(void)
{
unsigned int cpu = smp_processor_id();
struct clock_event_device *clk = &per_cpu(local_clockevent, cpu);

clk->name = "dummy_timer";
clk->features = CLOCK_EVT_FEAT_ONESHOT |
CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_DUMMY;
clk->rating = 400;
clk->mult = 1;
clk->set_mode = dummy_timer_set_mode;
clk->broadcast = smp_timer_broadcast;
clk->cpumask = cpumask_of(cpu);

clockevents_register_device(clk);
}

#endif /* !CONFIG_LOCAL_TIMERS */
#endif /* CONFIG_LOCAL_TIMERS */
14 changes: 7 additions & 7 deletions arch/arm/mach-realview/platsmp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@
#include <asm/cacheflush.h>
#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <asm/localtimer.h>

#include <mach/board-eb.h>
#include <mach/board-pb11mp.h>
Expand Down Expand Up @@ -217,13 +218,6 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
if (max_cpus > ncores)
max_cpus = ncores;

#if defined(CONFIG_LOCAL_TIMERS) || defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
/*
* Enable the local timer or broadcast device for the boot CPU.
*/
local_timer_setup();
#endif

/*
* Initialise the present map, which describes the set of CPUs
* actually populated at the present time.
Expand All @@ -239,6 +233,12 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
* WFI
*/
if (max_cpus > 1) {
/*
* Enable the local timer or broadcast device for the
* boot CPU, but only if we have more than one CPU.
*/
percpu_timer_setup();

scu_enable();
poke_milo();
}
Expand Down

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