[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / mach-realview / hotplug.c

/*
 *  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/cacheflush.h>

extern volatile int pen_release;

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

	flush_cache_all();
	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)
{
	return 1;
}

/*
 * platform-specific code to shutdown a CPU
 *
 * Called with IRQs disabled
 */
void platform_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);
}

int platform_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;
}
Commit	Line	Data
97a63ecf RK	1	/*
	2	* linux/arch/arm/mach-realview/hotplug.c
	3	*
	4	* Copyright (C) 2002 ARM Ltd.
	5	* All Rights Reserved
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11	#include <linux/kernel.h>
	12	#include <linux/errno.h>
	13	#include <linux/smp.h>
97a63ecf	14
8aa2da87 HF	15	#include <asm/cacheflush.h>
8aa2da87 HF	16
97a63ecf RK	17	extern volatile int pen_release;
97a63ecf RK	18
97a63ecf RK	19	static inline void cpu_enter_lowpower(void)
	20	{
	21	unsigned int v;
	22
8aa2da87 HF	23	flush_cache_all();
8aa2da87 HF	24	asm volatile(
97a63ecf RK	25	" mcr p15, 0, %1, c7, c5, 0\n"
	26	" mcr p15, 0, %1, c7, c10, 4\n"
	27	/*
	28	* Turn off coherency
	29	*/
	30	" mrc p15, 0, %0, c1, c0, 1\n"
	31	" bic %0, %0, #0x20\n"
	32	" mcr p15, 0, %0, c1, c0, 1\n"
	33	" mrc p15, 0, %0, c1, c0, 0\n"
e3d9c625	34	" bic %0, %0, %2\n"
97a63ecf RK	35	" mcr p15, 0, %0, c1, c0, 0\n"
97a63ecf RK	36	: "=&r" (v)
e3d9c625	37	: "r" (0), "Ir" (CR_C)
97a63ecf RK	38	: "cc");
	39	}
	40
	41	static inline void cpu_leave_lowpower(void)
	42	{
	43	unsigned int v;
	44
	45	asm volatile( "mrc p15, 0, %0, c1, c0, 0\n"
e3d9c625	46	" orr %0, %0, %1\n"
97a63ecf RK	47	" mcr p15, 0, %0, c1, c0, 0\n"
	48	" mrc p15, 0, %0, c1, c0, 1\n"
	49	" orr %0, %0, #0x20\n"
	50	" mcr p15, 0, %0, c1, c0, 1\n"
	51	: "=&r" (v)
e3d9c625	52	: "Ir" (CR_C)
97a63ecf RK	53	: "cc");
	54	}
	55
d4450261	56	static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
97a63ecf RK	57	{
	58	/*
	59	* there is no power-control hardware on this platform, so all
	60	* we can do is put the core into WFI; this is safe as the calling
	61	* code will have already disabled interrupts
	62	*/
	63	for (;;) {
	64	/*
	65	* here's the WFI
	66	*/
	67	asm(".word 0xe320f003\n"
	68	:
	69	:
	70	: "memory", "cc");
	71
	72	if (pen_release == cpu) {
	73	/*
	74	* OK, proper wakeup, we're done
	75	*/
	76	break;
	77	}
	78
	79	/*
d4450261	80	* Getting here, means that we have come out of WFI without
97a63ecf RK	81	* having been woken up - this shouldn't happen
97a63ecf RK	82	*
d4450261 RK	83	* Just note it happening - when we're woken, we can report
d4450261 RK	84	* its occurrence.
97a63ecf	85	*/
d4450261	86	(*spurious)++;
97a63ecf RK	87	}
	88	}
	89
	90	int platform_cpu_kill(unsigned int cpu)
	91	{
3c030bea	92	return 1;
97a63ecf RK	93	}
	94
	95	/*
	96	* platform-specific code to shutdown a CPU
	97	*
	98	* Called with IRQs disabled
	99	*/
	100	void platform_cpu_die(unsigned int cpu)
	101	{
d4450261 RK	102	int spurious = 0;
d4450261 RK	103
97a63ecf RK	104	/*
	105	* we're ready for shutdown now, so do it
	106	*/
	107	cpu_enter_lowpower();
d4450261	108	platform_do_lowpower(cpu, &spurious);
97a63ecf RK	109
	110	/*
	111	* bring this CPU back into the world of cache
	112	* coherency, and then restore interrupts
	113	*/
	114	cpu_leave_lowpower();
d4450261 RK	115
	116	if (spurious)
	117	pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
97a63ecf RK	118	}
97a63ecf RK	119
8e2a43f5	120	int platform_cpu_disable(unsigned int cpu)
97a63ecf RK	121	{
	122	/*
	123	* we don't allow CPU 0 to be shutdown (it is still too special
	124	* e.g. clock tick interrupts)
	125	*/
	126	return cpu == 0 ? -EPERM : 0;
	127	}