[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / mach-tegra / 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>

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
1cea7326 CC	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>
1cea7326 CC	14
	15	#include <asm/cacheflush.h>
	16
1cea7326 CC	17	static inline void cpu_enter_lowpower(void)
	18	{
	19	unsigned int v;
	20
	21	flush_cache_all();
	22	asm volatile(
	23	" mcr p15, 0, %1, c7, c5, 0\n"
	24	" mcr p15, 0, %1, c7, c10, 4\n"
	25	/*
	26	* Turn off coherency
	27	*/
	28	" mrc p15, 0, %0, c1, c0, 1\n"
30b99d07	29	" bic %0, %0, #0x20\n"
1cea7326 CC	30	" mcr p15, 0, %0, c1, c0, 1\n"
1cea7326 CC	31	" mrc p15, 0, %0, c1, c0, 0\n"
30b99d07	32	" bic %0, %0, %2\n"
1cea7326 CC	33	" mcr p15, 0, %0, c1, c0, 0\n"
1cea7326 CC	34	: "=&r" (v)
e3d9c625	35	: "r" (0), "Ir" (CR_C)
1cea7326 CC	36	: "cc");
	37	}
	38
	39	static inline void cpu_leave_lowpower(void)
	40	{
	41	unsigned int v;
	42
	43	asm volatile(
	44	"mrc p15, 0, %0, c1, c0, 0\n"
e3d9c625	45	" orr %0, %0, %1\n"
1cea7326 CC	46	" mcr p15, 0, %0, c1, c0, 0\n"
	47	" mrc p15, 0, %0, c1, c0, 1\n"
	48	" orr %0, %0, #0x20\n"
	49	" mcr p15, 0, %0, c1, c0, 1\n"
	50	: "=&r" (v)
e3d9c625	51	: "Ir" (CR_C)
1cea7326 CC	52	: "cc");
	53	}
	54
d4450261	55	static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
1cea7326 CC	56	{
	57	/*
	58	* there is no power-control hardware on this platform, so all
	59	* we can do is put the core into WFI; this is safe as the calling
	60	* code will have already disabled interrupts
	61	*/
	62	for (;;) {
	63	/*
	64	* here's the WFI
	65	*/
	66	asm(".word 0xe320f003\n"
	67	:
	68	:
	69	: "memory", "cc");
	70
	71	/if (pen_release == cpu) {/
	72	/*
	73	* OK, proper wakeup, we're done
	74	*/
	75	break;
	76	/}/
	77
	78	/*
d4450261	79	* Getting here, means that we have come out of WFI without
1cea7326 CC	80	* having been woken up - this shouldn't happen
1cea7326 CC	81	*
d4450261 RK	82	* Just note it happening - when we're woken, we can report
d4450261 RK	83	* its occurrence.
1cea7326	84	*/
d4450261	85	(*spurious)++;
1cea7326 CC	86	}
	87	}
	88
	89	int platform_cpu_kill(unsigned int cpu)
	90	{
3c030bea	91	return 1;
1cea7326 CC	92	}
	93
	94	/*
	95	* platform-specific code to shutdown a CPU
	96	*
	97	* Called with IRQs disabled
	98	*/
	99	void platform_cpu_die(unsigned int cpu)
	100	{
d4450261 RK	101	int spurious = 0;
d4450261 RK	102
1cea7326 CC	103	/*
	104	* we're ready for shutdown now, so do it
	105	*/
	106	cpu_enter_lowpower();
d4450261	107	platform_do_lowpower(cpu, &spurious);
1cea7326 CC	108
	109	/*
	110	* bring this CPU back into the world of cache
	111	* coherency, and then restore interrupts
	112	*/
	113	cpu_leave_lowpower();
d4450261 RK	114
	115	if (spurious)
	116	pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
1cea7326 CC	117	}
	118
	119	int platform_cpu_disable(unsigned int cpu)
	120	{
	121	/*
	122	* we don't allow CPU 0 to be shutdown (it is still too special
	123	* e.g. clock tick interrupts)
	124	*/
	125	return cpu == 0 ? -EPERM : 0;
	126	}