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Commit 59b0f682 authored by Joseph Lo's avatar Joseph Lo Committed by Stephen Warren
Browse files

ARM: tegra30: add CPU hotplug support 



Hotplug function put CPUs in offline or online state at runtime.
When the CPU been put in the offline state, it was been clock and
power gated. Except primary CPU other CPUs can be hotplugged.

Based on the work by:
Scott Williams <scwilliams@nvidia.com>
Colin Cross <ccross@android.com>
Gary King <gking@nvidia.com>

Signed-off-by: default avatarJoseph Lo <josephl@nvidia.com>
Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
parent c2be5bfc

arch/arm/mach-tegra/Makefile

+1 −0
Original line number Original line Diff line number Diff line
@@ -17,6 +17,7 @@ obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra20_clocks_data.o 
obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= tegra2_emc.o

obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= tegra2_emc.o

obj-$(CONFIG_ARCH_TEGRA_3x_SOC)		+= tegra30_clocks.o

obj-$(CONFIG_ARCH_TEGRA_3x_SOC)		+= tegra30_clocks.o

obj-$(CONFIG_ARCH_TEGRA_3x_SOC)		+= tegra30_clocks_data.o

obj-$(CONFIG_ARCH_TEGRA_3x_SOC)		+= tegra30_clocks_data.o

obj-$(CONFIG_ARCH_TEGRA_3x_SOC)		+= sleep-t30.o

obj-$(CONFIG_SMP)			+= platsmp.o headsmp.o

obj-$(CONFIG_SMP)			+= platsmp.o headsmp.o

obj-$(CONFIG_SMP)                       += reset.o

obj-$(CONFIG_SMP)                       += reset.o

obj-$(CONFIG_HOTPLUG_CPU)               += hotplug.o

obj-$(CONFIG_HOTPLUG_CPU)               += hotplug.o

arch/arm/mach-tegra/common.c

+2 −0
Original line number Original line Diff line number Diff line
@@ -34,6 +34,7 @@ 
#include "fuse.h"

#include "fuse.h"

#include "pmc.h"

#include "pmc.h"

#include "apbio.h"

#include "apbio.h"

#include "sleep.h"





/*

/*

 * Storage for debug-macro.S's state.

 * Storage for debug-macro.S's state.
@@ -147,6 +148,7 @@ void __init tegra30_init_early(void) 
	tegra_init_cache(0x441, 0x551);

	tegra_init_cache(0x441, 0x551);

	tegra_pmc_init();

	tegra_pmc_init();

	tegra_powergate_init();

	tegra_powergate_init();

	tegra30_hotplug_init();

}

}

#endif

#endif

arch/arm/mach-tegra/hotplug.c

+24 −86
Original line number Original line Diff line number Diff line 
/*

/*

 *  linux/arch/arm/mach-realview/hotplug.c

 *

 *

 *  Copyright (C) 2002 ARM Ltd.

 *  Copyright (C) 2002 ARM Ltd.

 *  All Rights Reserved

 *  All Rights Reserved

 *  Copyright (c) 2010, 2012 NVIDIA Corporation. All rights reserved.

 *

 *

 * This program is free software; you can redistribute it and/or modify

 * 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

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 * published by the Free Software Foundation.

 */

 */

#include <linux/kernel.h>

#include <linux/kernel.h>

#include <linux/errno.h>

#include <linux/smp.h>

#include <linux/smp.h>





#include <asm/cacheflush.h>

#include <asm/cacheflush.h>

#include <asm/cp15.h>

#include <asm/smp_plat.h>





static inline void cpu_enter_lowpower(void)

#include "sleep.h"

{

#include "tegra_cpu_car.h"

	unsigned int v;





	flush_cache_all();

static void (*tegra_hotplug_shutdown)(void);

	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) {*/

			/*

			 * 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)++;

	}

}





int platform_cpu_kill(unsigned int cpu)

int platform_cpu_kill(unsigned int cpu)

{

{
@@ -99,22 +31,20 @@ int platform_cpu_kill(unsigned int cpu) 
 */

 */

void platform_cpu_die(unsigned int cpu)

void platform_cpu_die(unsigned int cpu)

{

{

	int spurious = 0;

	cpu = cpu_logical_map(cpu);





	/*

	/* Flush the L1 data cache. */

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

	flush_cache_all();

	 */

	cpu_enter_lowpower();

	platform_do_lowpower(cpu, &spurious);





	/*

	/* Shut down the current CPU. */

	 * bring this CPU back into the world of cache

	tegra_hotplug_shutdown();

	 * coherency, and then restore interrupts

	 */

	cpu_leave_lowpower();





	if (spurious)

	/* Clock gate the CPU */

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

	tegra_wait_cpu_in_reset(cpu);

	tegra_disable_cpu_clock(cpu);



	/* Should never return here. */

	BUG();

}

}





int platform_cpu_disable(unsigned int cpu)

int platform_cpu_disable(unsigned int cpu)
@@ -125,3 +55,11 @@ int platform_cpu_disable(unsigned int cpu) 
	 */

	 */

	return cpu == 0 ? -EPERM : 0;

	return cpu == 0 ? -EPERM : 0;

}

}



#ifdef CONFIG_ARCH_TEGRA_3x_SOC

extern void tegra30_hotplug_shutdown(void);

void __init tegra30_hotplug_init(void)

{

	tegra_hotplug_shutdown = tegra30_hotplug_shutdown;

}

#endif

arch/arm/mach-tegra/sleep-t30.S

0 → 100644
+107 −0
Original line number Original line Diff line number Diff line 
/*

 * Copyright (c) 2012, NVIDIA Corporation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

 * more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */



#include <linux/linkage.h>



#include <asm/assembler.h>



#include <mach/iomap.h>



#include "sleep.h"

#include "flowctrl.h"



#define TEGRA30_POWER_HOTPLUG_SHUTDOWN	(1 << 27) /* Hotplug shutdown */



#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PM_SLEEP)

/*

 * tegra30_hotplug_shutdown(void)

 *

 * Powergates the current CPU.

 * Should never return.

 */

ENTRY(tegra30_hotplug_shutdown)

	/* Turn off SMP coherency */

	exit_smp r4, r5



	/* Powergate this CPU */

	mov	r0, #TEGRA30_POWER_HOTPLUG_SHUTDOWN

	bl	tegra30_cpu_shutdown

	mov	pc, lr			@ should never get here

ENDPROC(tegra30_hotplug_shutdown)



/*

 * tegra30_cpu_shutdown(unsigned long flags)

 *

 * Puts the current CPU in wait-for-event mode on the flow controller

 * and powergates it -- flags (in R0) indicate the request type.

 * Must never be called for CPU 0.

 *

 * corrupts r0-r4, r12

 */

ENTRY(tegra30_cpu_shutdown)

	cpu_id	r3

	cmp	r3, #0

	moveq	pc, lr		@ Must never be called for CPU 0



	ldr	r12, =TEGRA_FLOW_CTRL_VIRT

	cpu_to_csr_reg r1, r3

	add	r1, r1, r12	@ virtual CSR address for this CPU

	cpu_to_halt_reg r2, r3

	add	r2, r2, r12	@ virtual HALT_EVENTS address for this CPU



	/*

	 * Clear this CPU's "event" and "interrupt" flags and power gate

	 * it when halting but not before it is in the "WFE" state.

	 */

	movw	r12, \

		FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG | \

		FLOW_CTRL_CSR_ENABLE

	mov	r4, #(1 << 4)

	orr	r12, r12, r4, lsl r3

	str	r12, [r1]



	/* Halt this CPU. */

	mov	r3, #0x400

delay_1:

	subs	r3, r3, #1			@ delay as a part of wfe war.

	bge	delay_1;

	cpsid	a				@ disable imprecise aborts.

	ldr	r3, [r1]			@ read CSR

	str	r3, [r1]			@ clear CSR

	tst	r0, #TEGRA30_POWER_HOTPLUG_SHUTDOWN

	movne	r3, #FLOW_CTRL_WAITEVENT		@ For hotplug

	str	r3, [r2]

	ldr	r0, [r2]

	b	wfe_war



__cpu_reset_again:

	dsb

	.align 5

	wfe					@ CPU should be power gated here

wfe_war:

	b	__cpu_reset_again



	/*

	 * 38 nop's, which fills reset of wfe cache line and

	 * 4 more cachelines with nop

	 */

	.rept 38

	nop

	.endr

	b	.				@ should never get here



ENDPROC(tegra30_cpu_shutdown)

#endif

arch/arm/mach-tegra/sleep.h

+25 −0
Original line number Original line Diff line number Diff line
@@ -19,6 +19,8 @@ 




#include <mach/iomap.h>

#include <mach/iomap.h>





#define TEGRA_ARM_PERIF_VIRT (TEGRA_ARM_PERIF_BASE - IO_CPU_PHYS \

					+ IO_CPU_VIRT)

#define TEGRA_FLOW_CTRL_VIRT (TEGRA_FLOW_CTRL_BASE - IO_PPSB_PHYS \

#define TEGRA_FLOW_CTRL_VIRT (TEGRA_FLOW_CTRL_BASE - IO_PPSB_PHYS \

					+ IO_PPSB_VIRT)

					+ IO_PPSB_VIRT)
@@ -52,5 +54,28 @@ 
	movw	\reg, #:lower16:\val

	movw	\reg, #:lower16:\val

	movt	\reg, #:upper16:\val

	movt	\reg, #:upper16:\val

.endm

.endm



/* Macro to exit SMP coherency. */

.macro exit_smp, tmp1, tmp2

	mrc	p15, 0, \tmp1, c1, c0, 1	@ ACTLR

	bic	\tmp1, \tmp1, #(1<<6) | (1<<0)	@ clear ACTLR.SMP | ACTLR.FW

	mcr	p15, 0, \tmp1, c1, c0, 1	@ ACTLR

	isb

	cpu_id	\tmp1

	mov	\tmp1, \tmp1, lsl #2

	mov	\tmp2, #0xf

	mov	\tmp2, \tmp2, lsl \tmp1

	mov32	\tmp1, TEGRA_ARM_PERIF_VIRT + 0xC

	str	\tmp2, [\tmp1]			@ invalidate SCU tags for CPU

	dsb

.endm

#else



#ifdef CONFIG_HOTPLUG_CPU

void tegra30_hotplug_init(void);

#else

static inline void tegra30_hotplug_init(void) {}

#endif



#endif

#endif

#endif
 
#endif