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Commit 6c0dda2c authored by Arve Hjønnevåg's avatar Arve Hjønnevåg Committed by Dmitry Shmidt
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ANDROID: ARM: fiq_glue: Add custom fiq return handler api. 



Change-Id: I5ff2764e85151ca0a88576542fda07c2d33dd065
Signed-off-by: default avatarArve Hjønnevåg <arve@android.com>
parent dad5647a

arch/arm/common/fiq_glue.S

+16 −9
Original line number Diff line number Diff line
@@ -22,13 +22,14 @@ 
		/* fiq stack: r0-r15,cpsr,spsr of interrupted mode */



ENTRY(fiq_glue)

		/* store pc, cpsr from previous mode */

		/* store pc, cpsr from previous mode, reserve space for spsr */

		mrs	r12, spsr

		sub	r11, lr, #4

		sub	lr, lr, #4

		subs	r10, #1

		bne	nested_fiq



		stmfd	sp!, {r11-r12, lr}

		str	r12, [sp, #-8]!

		str	lr, [sp, #-4]!



		/* store r8-r14 from previous mode */

		sub	sp, sp, #(7 * 4)
@@ -85,12 +86,15 @@ fiq_from_usr_mode_exit: 
		msr	cpsr_c, #(FIQ_MODE | PSR_I_BIT | PSR_F_BIT)



		ldmfd	sp!, {r0-r7}

		add	sp, sp, #(7 * 4)

		ldmfd	sp!, {r11-r12, lr}

		ldr	lr, [sp, #(4 * 7)]

		ldr	r12, [sp, #(4 * 8)]

		add	sp, sp, #(10 * 4)

exit_fiq:

		msr	spsr_cxsf, r12

		add	r10, #1

		movs	pc, r11

		cmp	r11, #0

		moveqs	pc, lr

		bx	r11 /* jump to custom fiq return function */



nested_fiq:

		orr	r12, r12, #(PSR_F_BIT)
@@ -98,14 +102,17 @@ nested_fiq: 


fiq_glue_end:



ENTRY(fiq_glue_setup) /* func, data, sp */

		mrs		r3, cpsr

ENTRY(fiq_glue_setup) /* func, data, sp, smc call number */

		stmfd		sp!, {r4}

		mrs		r4, cpsr

		msr		cpsr_c, #(FIQ_MODE | PSR_I_BIT | PSR_F_BIT)

		movs		r8, r0

		mov		r9, r1

		mov		sp, r2

		mov		r11, r3

		moveq		r10, #0

		movne		r10, #1

		msr		cpsr_c, r3

		msr		cpsr_c, r4

		ldmfd		sp!, {r4}

		bx		lr

arch/arm/common/fiq_glue_setup.c

+50 −3
Original line number Diff line number Diff line
@@ -18,20 +18,23 @@ 
#include <asm/fiq_glue.h>



extern unsigned char fiq_glue, fiq_glue_end;

extern void fiq_glue_setup(void *func, void *data, void *sp);

extern void fiq_glue_setup(void *func, void *data, void *sp,

			   fiq_return_handler_t fiq_return_handler);



static struct fiq_handler fiq_debbuger_fiq_handler = {

	.name = "fiq_glue",

};

DEFINE_PER_CPU(void *, fiq_stack);

static struct fiq_glue_handler *current_handler;

static fiq_return_handler_t fiq_return_handler;

static DEFINE_MUTEX(fiq_glue_lock);



static void fiq_glue_setup_helper(void *info)

{

	struct fiq_glue_handler *handler = info;

	fiq_glue_setup(handler->fiq, handler,

		__get_cpu_var(fiq_stack) + THREAD_START_SP);

		__get_cpu_var(fiq_stack) + THREAD_START_SP,

		fiq_return_handler);

}



int fiq_glue_register_handler(struct fiq_glue_handler *handler)
@@ -80,6 +83,49 @@ int fiq_glue_register_handler(struct fiq_glue_handler *handler) 
	return ret;

}



static void fiq_glue_update_return_handler(void (*fiq_return)(void))

{

	fiq_return_handler = fiq_return;

	if (current_handler)

		on_each_cpu(fiq_glue_setup_helper, current_handler, true);

}



int fiq_glue_set_return_handler(void (*fiq_return)(void))

{

	int ret;



	mutex_lock(&fiq_glue_lock);

	if (fiq_return_handler) {

		ret = -EBUSY;

		goto err_busy;

	}

	fiq_glue_update_return_handler(fiq_return);

	ret = 0;

err_busy:

	mutex_unlock(&fiq_glue_lock);



	return ret;

}

EXPORT_SYMBOL(fiq_glue_set_return_handler);



int fiq_glue_clear_return_handler(void (*fiq_return)(void))

{

	int ret;



	mutex_lock(&fiq_glue_lock);

	if (WARN_ON(fiq_return_handler != fiq_return)) {

		ret = -EINVAL;

		goto err_inval;

	}

	fiq_glue_update_return_handler(NULL);

	ret = 0;

err_inval:

	mutex_unlock(&fiq_glue_lock);



	return ret;

}

EXPORT_SYMBOL(fiq_glue_clear_return_handler);



/**

 * fiq_glue_resume - Restore fiqs after suspend or low power idle states

 *
@@ -93,7 +139,8 @@ void fiq_glue_resume(void) 
	if (!current_handler)

		return;

	fiq_glue_setup(current_handler->fiq, current_handler,

		__get_cpu_var(fiq_stack) + THREAD_START_SP);

		__get_cpu_var(fiq_stack) + THREAD_START_SP,

		fiq_return_handler);

	if (current_handler->resume)

		current_handler->resume(current_handler);

}

arch/arm/include/asm/fiq_glue.h

+3 −0
Original line number Diff line number Diff line
@@ -18,8 +18,11 @@ struct fiq_glue_handler { 
	void (*fiq)(struct fiq_glue_handler *h, void *regs, void *svc_sp);

	void (*resume)(struct fiq_glue_handler *h);

};

typedef void (*fiq_return_handler_t)(void);



int fiq_glue_register_handler(struct fiq_glue_handler *handler);

int fiq_glue_set_return_handler(fiq_return_handler_t fiq_return);

int fiq_glue_clear_return_handler(fiq_return_handler_t fiq_return);



#ifdef CONFIG_FIQ_GLUE

void fiq_glue_resume(void);