[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / mach-vexpress / 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, %3\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), "Ir" (0x40)
	  : "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, %2\n"
	"	mcr	p15, 0, %0, c1, c0, 1\n"
	  : "=&r" (v)
	  : "Ir" (CR_C), "Ir" (0x40)
	  : "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
e9882777 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>
	14
	15	#include <asm/cacheflush.h>
	16
	17	extern volatile int pen_release;
	18
	19	static inline void cpu_enter_lowpower(void)
	20	{
	21	unsigned int v;
	22
	23	flush_cache_all();
	24	asm volatile(
	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, %3\n"
	32	" mcr p15, 0, %0, c1, c0, 1\n"
	33	" mrc p15, 0, %0, c1, c0, 0\n"
	34	" bic %0, %0, %2\n"
	35	" mcr p15, 0, %0, c1, c0, 0\n"
	36	: "=&r" (v)
	37	: "r" (0), "Ir" (CR_C), "Ir" (0x40)
	38	: "cc");
	39	}
	40
	41	static inline void cpu_leave_lowpower(void)
	42	{
	43	unsigned int v;
	44
	45	asm volatile(
	46	"mrc p15, 0, %0, c1, c0, 0\n"
	47	" orr %0, %0, %1\n"
	48	" mcr p15, 0, %0, c1, c0, 0\n"
	49	" mrc p15, 0, %0, c1, c0, 1\n"
	50	" orr %0, %0, %2\n"
	51	" mcr p15, 0, %0, c1, c0, 1\n"
	52	: "=&r" (v)
	53	: "Ir" (CR_C), "Ir" (0x40)
	54	: "cc");
	55	}
	56
	57	static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
	58	{
	59	/*
	60	* there is no power-control hardware on this platform, so all
	61	* we can do is put the core into WFI; this is safe as the calling
	62	* code will have already disabled interrupts
	63	*/
	64	for (;;) {
65	/*
66	* here's the WFI
67	*/
68	asm(".word 0xe320f003\n"
69	:
70	:
71	: "memory", "cc");
72
73	if (pen_release == cpu) {
74	/*
75	* OK, proper wakeup, we're done
76	*/
77	break;
78	}
79
80	/*
81	* Getting here, means that we have come out of WFI without
82	* having been woken up - this shouldn't happen
83	*
84	* Just note it happening - when we're woken, we can report
85	* its occurrence.
86	*/
87	(*spurious)++;
88	}
89	}
90
91	int platform_cpu_kill(unsigned int cpu)
92	{
93	return 1;
94	}
95
96	/*
97	* platform-specific code to shutdown a CPU
98	*
99	* Called with IRQs disabled
100	*/
101	void platform_cpu_die(unsigned int cpu)
102	{
103	int spurious = 0;
104
105	/*
106	* we're ready for shutdown now, so do it
107	*/
108	cpu_enter_lowpower();
109	platform_do_lowpower(cpu, &spurious);
110
111	/*
112	* bring this CPU back into the world of cache
113	* coherency, and then restore interrupts
114	*/
115	cpu_leave_lowpower();
116
117	if (spurious)
118	pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
119	}
120
121	int platform_cpu_disable(unsigned int cpu)
122	{
123	/*
124	* we don't allow CPU 0 to be shutdown (it is still too special
125	* e.g. clock tick interrupts)
126	*/
127	return cpu == 0 ? -EPERM : 0;
128	}