Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit be6eb9b7 authored by Russell King's avatar Russell King Committed by Russell King
Browse files

Merge with ARM SMP tree

parents c906107b 97a63ecf
Loading
Loading
Loading
Loading
+1 −1
Original line number Diff line number Diff line
@@ -358,7 +358,7 @@ config HOTPLUG_CPU

config LOCAL_TIMERS
	bool "Use local timer interrupts"
	depends on SMP && n
	depends on SMP && REALVIEW_MPCORE
	default y
	help
	  Enable support for local timers on SMP platforms, rather then the
+2 −0
Original line number Diff line number Diff line
@@ -5,3 +5,5 @@
obj-y					:= core.o clock.o
obj-$(CONFIG_MACH_REALVIEW_EB)		+= realview_eb.o
obj-$(CONFIG_SMP)			+= platsmp.o headsmp.o
obj-$(CONFIG_HOTPLUG_CPU)		+= hotplug.o
obj-$(CONFIG_LOCAL_TIMERS)		+= localtimer.o
+1 −1
Original line number Diff line number Diff line
@@ -550,7 +550,7 @@ static irqreturn_t realview_timer_interrupt(int irq, void *dev_id, struct pt_reg

	timer_tick(regs);

#ifdef CONFIG_SMP
#if defined(CONFIG_SMP) && !defined(CONFIG_LOCAL_TIMERS)
	smp_send_timer();
	update_process_times(user_mode(regs));
#endif
+138 −0
Original line number Diff line number Diff line
/*
 *  linux/arch/arm/mach-realview/hotplug.c
 *
 *  Copyright (C) 2002 ARM Ltd.
 *  All Rights Reserved
 *
 * 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.
 */
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/smp.h>
#include <linux/completion.h>

extern volatile int pen_release;

static DECLARE_COMPLETION(cpu_killed);

static inline void cpu_enter_lowpower(void)
{
	unsigned int v;

	asm volatile(	"mcr	p15, 0, %1, c7, c14, 0\n"
	"	mcr	p15, 0, %1, c7, c5, 0\n"
	"	mcr	p15, 0, %1, c7, c10, 4\n"
	/*
	 * Turn off coherency
	 */
	"	mrc	p15, 0, %0, c1, c0, 1\n"
	"	bic	%0, %0, #0x20\n"
	"	mcr	p15, 0, %0, c1, c0, 1\n"
	"	mrc	p15, 0, %0, c1, c0, 0\n"
	"	bic	%0, %0, #0x04\n"
	"	mcr	p15, 0, %0, c1, c0, 0\n"
	  : "=&r" (v)
	  : "r" (0)
	  : "cc");
}

static inline void cpu_leave_lowpower(void)
{
	unsigned int v;

	asm volatile(	"mrc	p15, 0, %0, c1, c0, 0\n"
	"	orr	%0, %0, #0x04\n"
	"	mcr	p15, 0, %0, c1, c0, 0\n"
	"	mrc	p15, 0, %0, c1, c0, 1\n"
	"	orr	%0, %0, #0x20\n"
	"	mcr	p15, 0, %0, c1, c0, 1\n"
	  : "=&r" (v)
	  :
	  : "cc");
}

static inline void platform_do_lowpower(unsigned int cpu)
{
	/*
	 * there is no power-control hardware on this platform, so all
	 * we can do is put the core into WFI; this is safe as the calling
	 * code will have already disabled interrupts
	 */
	for (;;) {
		/*
		 * here's the WFI
		 */
		asm(".word	0xe320f003\n"
		    :
		    :
		    : "memory", "cc");

		if (pen_release == cpu) {
			/*
			 * OK, proper wakeup, we're done
			 */
			break;
		}

		/*
		 * getting here, means that we have come out of WFI without
		 * having been woken up - this shouldn't happen
		 *
		 * The trouble is, letting people know about this is not really
		 * possible, since we are currently running incoherently, and
		 * therefore cannot safely call printk() or anything else
		 */
#ifdef DEBUG
		printk("CPU%u: spurious wakeup call\n", cpu);
#endif
	}
}

int platform_cpu_kill(unsigned int cpu)
{
	return wait_for_completion_timeout(&cpu_killed, 5000);
}

/*
 * platform-specific code to shutdown a CPU
 *
 * Called with IRQs disabled
 */
void platform_cpu_die(unsigned int cpu)
{
#ifdef DEBUG
	unsigned int this_cpu = hard_smp_processor_id();

	if (cpu != this_cpu) {
		printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n",
			   this_cpu, cpu);
		BUG();
	}
#endif

	printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
	complete(&cpu_killed);

	/*
	 * we're ready for shutdown now, so do it
	 */
	cpu_enter_lowpower();
	platform_do_lowpower(cpu);

	/*
	 * bring this CPU back into the world of cache
	 * coherency, and then restore interrupts
	 */
	cpu_leave_lowpower();
}

int mach_cpu_disable(unsigned int cpu)
{
	/*
	 * we don't allow CPU 0 to be shutdown (it is still too special
	 * e.g. clock tick interrupts)
	 */
	return cpu == 0 ? -EPERM : 0;
}
+130 −0
Original line number Diff line number Diff line
/*
 *  linux/arch/arm/mach-realview/localtimer.c
 *
 *  Copyright (C) 2002 ARM Ltd.
 *  All Rights Reserved
 *
 * 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.
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/smp.h>

#include <asm/mach/time.h>
#include <asm/hardware/arm_twd.h>
#include <asm/hardware/gic.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/irq.h>

#include "core.h"

#define TWD_BASE(cpu)	(__io_address(REALVIEW_TWD_BASE) + \
			 ((cpu) * REALVIEW_TWD_SIZE))

static unsigned long mpcore_timer_rate;

/*
 * local_timer_ack: checks for a local timer interrupt.
 *
 * If a local timer interrupt has occured, acknowledge and return 1.
 * Otherwise, return 0.
 */
int local_timer_ack(void)
{
	void __iomem *base = TWD_BASE(smp_processor_id());

	if (__raw_readl(base + TWD_TIMER_INTSTAT)) {
		__raw_writel(1, base + TWD_TIMER_INTSTAT);
		return 1;
	}

	return 0;
}

void __cpuinit local_timer_setup(unsigned int cpu)
{
	void __iomem *base = TWD_BASE(cpu);
	unsigned int load, offset;
	u64 waitjiffies;
	unsigned int count;

	/*
	 * If this is the first time round, we need to work out how fast
	 * the timer ticks
	 */
	if (mpcore_timer_rate == 0) {
		printk("Calibrating local timer... ");

		/* Wait for a tick to start */
		waitjiffies = get_jiffies_64() + 1;

		while (get_jiffies_64() < waitjiffies)
			udelay(10);

		/* OK, now the tick has started, let's get the timer going */
		waitjiffies += 5;

				 /* enable, no interrupt or reload */
		__raw_writel(0x1, base + TWD_TIMER_CONTROL);

				 /* maximum value */
		__raw_writel(0xFFFFFFFFU, base + TWD_TIMER_COUNTER);

		while (get_jiffies_64() < waitjiffies)
			udelay(10);

		count = __raw_readl(base + TWD_TIMER_COUNTER);

		mpcore_timer_rate = (0xFFFFFFFFU - count) * (HZ / 5);

		printk("%lu.%02luMHz.\n", mpcore_timer_rate / 1000000,
			(mpcore_timer_rate / 100000) % 100);
	}

	load = mpcore_timer_rate / HZ;

	__raw_writel(load, base + TWD_TIMER_LOAD);
	__raw_writel(0x7,  base + TWD_TIMER_CONTROL);

	/*
	 * Now maneuver our local tick into the right part of the jiffy.
	 * Start by working out where within the tick our local timer
	 * interrupt should go.
	 */
	offset = ((mpcore_timer_rate / HZ) / (NR_CPUS + 1)) * (cpu + 1);

	/*
	 * gettimeoffset() will return a number of us since the last tick.
	 * Convert this number of us to a local timer tick count.
	 * Be careful of integer overflow whilst keeping maximum precision.
	 *
	 * with HZ=100 and 1MHz (fpga) ~ 1GHz processor:
	 * load = 1 ~ 10,000
	 * mpcore_timer_rate/10000 = 100 ~ 100,000
	 *
	 * so the multiply value will be less than 10^9 always.
	 */
	load = (system_timer->offset() * (mpcore_timer_rate / 10000)) / 100;

	/* Add on our offset to get the load value */
	load = (load + offset) % (mpcore_timer_rate / HZ);

	__raw_writel(load, base + TWD_TIMER_COUNTER);

	/* Make sure our local interrupt controller has this enabled */
	__raw_writel(1 << IRQ_LOCALTIMER,
		     __io_address(REALVIEW_GIC_DIST_BASE) + GIC_DIST_ENABLE_SET);
}

/*
 * take a local timer down
 */
void __cpuexit local_timer_stop(unsigned int cpu)
{
	__raw_writel(0, TWD_BASE(cpu) + TWD_TIMER_CONTROL);
}
Loading