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Commit 4fb68e12 authored by Russell King's avatar Russell King
Browse files

ARM: vexpress/realview: consolidate immitation CPU hotplug 



The only difference between the hotplug implementation for Realview
and Versatile Express are the bit in the auxiliary control register
to disable coherency.  Combine the two implentations accounting for
that difference.

Rename the functions to try to discourage cargo-cult copying of this
code.

Tested-by: default avatarSudeep Holla <sudeep.holla@arm.com>
Acked-by: default avatarSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
parent 65102238

arch/arm/mach-realview/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -5,4 +5,3 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/arch/arm/plat-versatile/inc 


obj-y					+= realview-dt.o

obj-$(CONFIG_SMP)			+= platsmp-dt.o
 
obj-$(CONFIG_HOTPLUG_CPU)		+= hotplug.o

arch/arm/mach-realview/hotplug.c

deleted100644 → 0
+0 −111
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 <asm/cp15.h>

#include <asm/smp_plat.h>



static inline void cpu_enter_lowpower(void)

{

	unsigned int v;



	asm volatile(

	"	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, %2\n"

	"	mcr	p15, 0, %0, c1, c0, 0\n"

	  : "=&r" (v)

	  : "r" (0), "Ir" (CR_C)

	  : "cc");

}



static inline void cpu_leave_lowpower(void)

{

	unsigned int v;



	asm volatile(	"mrc	p15, 0, %0, c1, c0, 0\n"

	"	orr	%0, %0, %1\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)

	  : "Ir" (CR_C)

	  : "cc");

}



static inline void platform_do_lowpower(unsigned int cpu, int *spurious)

{

	/*

	 * 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_logical_map(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

		 *

		 * Just note it happening - when we're woken, we can report

		 * its occurrence.

		 */

		(*spurious)++;

	}

}



/*

 * platform-specific code to shutdown a CPU

 *

 * Called with IRQs disabled

 */

void realview_cpu_die(unsigned int cpu)

{

	int spurious = 0;



	/*

	 * we're ready for shutdown now, so do it

	 */

	cpu_enter_lowpower();

	platform_do_lowpower(cpu, &spurious);



	/*

	 * bring this CPU back into the world of cache

	 * coherency, and then restore interrupts

	 */

	cpu_leave_lowpower();



	if (spurious)

		pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);

}

arch/arm/mach-realview/hotplug.h

deleted100644 → 0
+0 −1
Original line number Diff line number Diff line 
void realview_cpu_die(unsigned int cpu);

arch/arm/mach-realview/platsmp-dt.c

+7 −1
Original line number Diff line number Diff line
@@ -17,7 +17,6 @@ 
#include <asm/smp_scu.h>



#include <plat/platsmp.h>

#include "hotplug.h"



#define REALVIEW_SYS_FLAGSSET_OFFSET	0x30
@@ -79,6 +78,13 @@ static void __init realview_smp_prepare_cpus(unsigned int max_cpus) 
		     __pa_symbol(versatile_secondary_startup));

}



#ifdef CONFIG_HOTPLUG_CPU

static void realview_cpu_die(unsigned int cpu)

{

	return versatile_immitation_cpu_die(cpu, 0x20);

}

#endif



static const struct smp_operations realview_dt_smp_ops __initconst = {

	.smp_prepare_cpus	= realview_smp_prepare_cpus,

	.smp_secondary_init	= versatile_secondary_init,

arch/arm/mach-vexpress/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -15,6 +15,5 @@ obj-$(CONFIG_ARCH_VEXPRESS_TC2_PM) += tc2_pm.o 
CFLAGS_tc2_pm.o				+= -march=armv7-a

CFLAGS_REMOVE_tc2_pm.o			= -pg

obj-$(CONFIG_SMP)			+= platsmp.o

obj-$(CONFIG_HOTPLUG_CPU)		+= hotplug.o



obj-$(CONFIG_ARCH_MPS2)			+= v2m-mps2.o