[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / kernel / fiq.c

/*
 *  linux/arch/arm/kernel/fiq.c
 *
 *  Copyright (C) 1998 Russell King
 *  Copyright (C) 1998, 1999 Phil Blundell
 *
 *  FIQ support written by Philip Blundell <philb@gnu.org>, 1998.
 *
 *  FIQ support re-written by Russell King to be more generic
 *
 * We now properly support a method by which the FIQ handlers can
 * be stacked onto the vector.  We still do not support sharing
 * the FIQ vector itself.
 *
 * Operation is as follows:
 *  1. Owner A claims FIQ:
 *     - default_fiq relinquishes control.
 *  2. Owner A:
 *     - inserts code.
 *     - sets any registers,
 *     - enables FIQ.
 *  3. Owner B claims FIQ:
 *     - if owner A has a relinquish function.
 *       - disable FIQs.
 *       - saves any registers.
 *       - returns zero.
 *  4. Owner B:
 *     - inserts code.
 *     - sets any registers,
 *     - enables FIQ.
 *  5. Owner B releases FIQ:
 *     - Owner A is asked to reacquire FIQ:
 *	 - inserts code.
 *	 - restores saved registers.
 *	 - enables FIQ.
 *  6. Goto 3
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/seq_file.h>

#include <asm/cacheflush.h>
#include <asm/cp15.h>
#include <asm/fiq.h>
#include <asm/irq.h>
#include <asm/traps.h>

static unsigned long no_fiq_insn;

/* Default reacquire function
 * - we always relinquish FIQ control
 * - we always reacquire FIQ control
 */
static int fiq_def_op(void *ref, int relinquish)
{
	if (!relinquish)
		set_fiq_handler(&no_fiq_insn, sizeof(no_fiq_insn));

	return 0;
}

static struct fiq_handler default_owner = {
	.name	= "default",
	.fiq_op = fiq_def_op,
};

static struct fiq_handler *current_fiq = &default_owner;

int show_fiq_list(struct seq_file *p, int prec)
{
	if (current_fiq != &default_owner)
		seq_printf(p, "%*s:              %s\n", prec, "FIQ",
			current_fiq->name);

	return 0;
}

void set_fiq_handler(void *start, unsigned int length)
{
#if defined(CONFIG_CPU_USE_DOMAINS)
	memcpy((void *)0xffff001c, start, length);
#else
	memcpy(vectors_page + 0x1c, start, length);
#endif
	flush_icache_range(0xffff001c, 0xffff001c + length);
	if (!vectors_high())
		flush_icache_range(0x1c, 0x1c + length);
}

int claim_fiq(struct fiq_handler *f)
{
	int ret = 0;

	if (current_fiq) {
		ret = -EBUSY;

		if (current_fiq->fiq_op != NULL)
			ret = current_fiq->fiq_op(current_fiq->dev_id, 1);
	}

	if (!ret) {
		f->next = current_fiq;
		current_fiq = f;
	}

	return ret;
}

void release_fiq(struct fiq_handler *f)
{
	if (current_fiq != f) {
		printk(KERN_ERR "%s FIQ trying to release %s FIQ\n",
		       f->name, current_fiq->name);
		dump_stack();
		return;
	}

	do
		current_fiq = current_fiq->next;
	while (current_fiq->fiq_op(current_fiq->dev_id, 0));
}

static int fiq_start;

void enable_fiq(int fiq)
{
	enable_irq(fiq + fiq_start);
}

void disable_fiq(int fiq)
{
	disable_irq(fiq + fiq_start);
}

EXPORT_SYMBOL(set_fiq_handler);
EXPORT_SYMBOL(__set_fiq_regs);	/* defined in fiqasm.S */
EXPORT_SYMBOL(__get_fiq_regs);	/* defined in fiqasm.S */
EXPORT_SYMBOL(claim_fiq);
EXPORT_SYMBOL(release_fiq);
EXPORT_SYMBOL(enable_fiq);
EXPORT_SYMBOL(disable_fiq);

void __init init_FIQ(int start)
{
	no_fiq_insn = *(unsigned long *)0xffff001c;
	fiq_start = start;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/arm/kernel/fiq.c
	3	*
	4	* Copyright (C) 1998 Russell King
	5	* Copyright (C) 1998, 1999 Phil Blundell
	6	*
	7	* FIQ support written by Philip Blundell <philb@gnu.org>, 1998.
	8	*
	9	* FIQ support re-written by Russell King to be more generic
	10	*
	11	* We now properly support a method by which the FIQ handlers can
	12	* be stacked onto the vector. We still do not support sharing
	13	* the FIQ vector itself.
	14	*
	15	* Operation is as follows:
	16	* 1. Owner A claims FIQ:
	17	* - default_fiq relinquishes control.
	18	* 2. Owner A:
	19	* - inserts code.
	20	* - sets any registers,
	21	* - enables FIQ.
	22	* 3. Owner B claims FIQ:
	23	* - if owner A has a relinquish function.
	24	* - disable FIQs.
	25	* - saves any registers.
	26	* - returns zero.
	27	* 4. Owner B:
	28	* - inserts code.
	29	* - sets any registers,
	30	* - enables FIQ.
	31	* 5. Owner B releases FIQ:
	32	* - Owner A is asked to reacquire FIQ:
	33	* - inserts code.
	34	* - restores saved registers.
	35	* - enables FIQ.
	36	* 6. Goto 3
	37	*/
	38	#include <linux/module.h>
	39	#include <linux/kernel.h>
	40	#include <linux/init.h>
4a2581a0	41	#include <linux/interrupt.h>
1da177e4 LT	42	#include <linux/seq_file.h>
	43
	44	#include <asm/cacheflush.h>
15d07dc9	45	#include <asm/cp15.h>
1da177e4 LT	46	#include <asm/fiq.h>
1da177e4 LT	47	#include <asm/irq.h>
247055aa	48	#include <asm/traps.h>
1da177e4 LT	49
	50	static unsigned long no_fiq_insn;
	51
	52	/* Default reacquire function
	53	* - we always relinquish FIQ control
	54	* - we always reacquire FIQ control
	55	*/
	56	static int fiq_def_op(void *ref, int relinquish)
	57	{
	58	if (!relinquish)
	59	set_fiq_handler(&no_fiq_insn, sizeof(no_fiq_insn));
	60
	61	return 0;
	62	}
	63
	64	static struct fiq_handler default_owner = {
	65	.name = "default",
	66	.fiq_op = fiq_def_op,
	67	};
	68
	69	static struct fiq_handler *current_fiq = &default_owner;
	70
f13cd417	71	int show_fiq_list(struct seq_file *p, int prec)
1da177e4 LT	72	{
1da177e4 LT	73	if (current_fiq != &default_owner)
f13cd417 RK	74	seq_printf(p, "%*s: %s\n", prec, "FIQ",
f13cd417 RK	75	current_fiq->name);
1da177e4 LT	76
	77	return 0;
	78	}
	79
	80	void set_fiq_handler(void *start, unsigned int length)
	81	{
247055aa	82	#if defined(CONFIG_CPU_USE_DOMAINS)
1da177e4	83	memcpy((void *)0xffff001c, start, length);
247055aa CM	84	#else
	85	memcpy(vectors_page + 0x1c, start, length);
	86	#endif
1da177e4 LT	87	flush_icache_range(0xffff001c, 0xffff001c + length);
	88	if (!vectors_high())
	89	flush_icache_range(0x1c, 0x1c + length);
	90	}
	91
1da177e4 LT	92	int claim_fiq(struct fiq_handler *f)
	93	{
	94	int ret = 0;
	95
	96	if (current_fiq) {
	97	ret = -EBUSY;
	98
	99	if (current_fiq->fiq_op != NULL)
	100	ret = current_fiq->fiq_op(current_fiq->dev_id, 1);
	101	}
	102
	103	if (!ret) {
	104	f->next = current_fiq;
	105	current_fiq = f;
	106	}
	107
	108	return ret;
	109	}
	110
	111	void release_fiq(struct fiq_handler *f)
	112	{
	113	if (current_fiq != f) {
	114	printk(KERN_ERR "%s FIQ trying to release %s FIQ\n",
	115	f->name, current_fiq->name);
	116	dump_stack();
	117	return;
	118	}
	119
	120	do
	121	current_fiq = current_fiq->next;
	122	while (current_fiq->fiq_op(current_fiq->dev_id, 0));
	123	}
	124
bc89663a SG	125	static int fiq_start;
bc89663a SG	126
1da177e4 LT	127	void enable_fiq(int fiq)
1da177e4 LT	128	{
bc89663a	129	enable_irq(fiq + fiq_start);
1da177e4 LT	130	}
	131
	132	void disable_fiq(int fiq)
	133	{
bc89663a	134	disable_irq(fiq + fiq_start);
1da177e4 LT	135	}
	136
	137	EXPORT_SYMBOL(set_fiq_handler);
dc2eb928 DM	138	EXPORT_SYMBOL(__set_fiq_regs); /* defined in fiqasm.S */
dc2eb928 DM	139	EXPORT_SYMBOL(__get_fiq_regs); /* defined in fiqasm.S */
1da177e4 LT	140	EXPORT_SYMBOL(claim_fiq);
	141	EXPORT_SYMBOL(release_fiq);
	142	EXPORT_SYMBOL(enable_fiq);
	143	EXPORT_SYMBOL(disable_fiq);
	144
bc89663a	145	void __init init_FIQ(int start)
1da177e4 LT	146	{
1da177e4 LT	147	no_fiq_insn = (unsigned long )0xffff001c;
bc89663a	148	fiq_start = start;
1da177e4	149	}