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Commit 2e8a5942 authored by Gregory CLEMENT's avatar Gregory CLEMENT Committed by Jason Cooper
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ARM: mvebu: Split low level functions to manipulate HW coherency 



Actually enabling coherency and adding a CPU on a SMP group are two
different operations which can be done separately. This patch splits
this in two functions.

Moreover as they use common pattern, this patch also creates local low
level functions (ll_get_coherency_base and ll_get_cpuid) to be used by
the exposed functions (ll_add_cpu_to_smp_group and
ll_enable_coherency)

Signed-off-by: default avatarGregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397488214-20685-6-git-send-email-gregory.clement@free-electrons.com


Signed-off-by: default avatarJason Cooper <jason@lakedaemon.net>
parent 952f4ca7

arch/arm/mach-mvebu/coherency.c

+5 −3
Original line number Diff line number Diff line
@@ -60,8 +60,9 @@ static struct of_device_id of_coherency_table[] = { 
	{ /* end of list */ },

};



/* Function defined in coherency_ll.S */

int ll_set_cpu_coherent(void);

/* Functions defined in coherency_ll.S */

int ll_enable_coherency(void);

void ll_add_cpu_to_smp_group(void);



int set_cpu_coherent(void)

{
@@ -71,7 +72,8 @@ int set_cpu_coherent(void) 
		return 1;

	}



	return ll_set_cpu_coherent();

	ll_add_cpu_to_smp_group();

	return ll_enable_coherency();

}



/*

arch/arm/mach-mvebu/coherency_ll.S

+62 −30
Original line number Diff line number Diff line
@@ -24,52 +24,84 @@ 
#include <asm/cp15.h>



	.text



ENTRY(ll_set_cpu_coherent)

/* Returns with the coherency address in r1 (r0 is untouched)*/

ENTRY(ll_get_coherency_base)

	mrc	p15, 0, r1, c1, c0, 0

	tst	r1, #CR_M @ Check MMU bit enabled

	bne	1f



	/* use physical address of the coherency register */

	adr	r0, 3f

	ldr	r3, [r0]

	ldr	r0, [r0, r3]

	adr	r1, 3f

	ldr	r3, [r1]

	ldr	r1, [r1, r3]

	b	2f

1:

	/* use virtual address of the coherency register */

	ldr	r0, =coherency_base

	ldr	r0, [r0]

	ldr	r1, =coherency_base

	ldr	r1, [r1]

2:

	/* Create bit by cpu index */

	mrc	15, 0, r1, cr0, cr0, 5

	and	r1, r1, #15

	mov	pc, lr

ENDPROC(ll_get_coherency_base)



/* Returns with the CPU ID in r3 (r0 is untouched)*/

ENTRY(ll_get_cpuid)

	mrc	15, 0, r3, cr0, cr0, 5

	and	r3, r3, #15

	mov	r2, #(1 << 24)

	lsl	r1, r2, r1

	lsl	r3, r2, r3

ARM_BE8(rev	r1, r1)

	mov	pc, lr

ENDPROC(ll_get_cpuid)



	/* Add CPU to SMP group - Atomic */

	add	r3, r0, #ARMADA_XP_CFB_CTL_REG_OFFSET

/* ll_add_cpu_to_smp_group, ll_enable_coherency and

 * ll_disable_coherency use strex/ldrex whereas MMU can be off. The

 * Armada XP SoC has an exclusive monitor that can track transactions

 * to Device and/or SO and as such also when MMU is disabled the

 * exclusive transactions will be functional

 */



ENTRY(ll_add_cpu_to_smp_group)

	/*

	 * r0 being untouched in ll_get_coherency_base and

	 * ll_get_cpuid, we can use it to save lr modifing it with the

	 * following bl

	 */

	mov r0, lr

	bl	ll_get_coherency_base

	bl	ll_get_cpuid

	mov lr, r0

	add	r0, r1, #ARMADA_XP_CFB_CFG_REG_OFFSET

1:

	ldrex	r2, [r3]

	orr	r2, r2, r1

	strex 	r0, r2, [r3]

	cmp	r0, #0

	ldrex	r2, [r0]

	orr	r2, r2, r3

	strex	r1, r2, [r0]

	cmp	r1, #0

	bne	1b

	mov	pc, lr

ENDPROC(ll_add_cpu_to_smp_group)



	/* Enable coherency on CPU - Atomic */

	add	r3, r3, #ARMADA_XP_CFB_CFG_REG_OFFSET

ENTRY(ll_enable_coherency)

	/*

	 * r0 being untouched in ll_get_coherency_base and

	 * ll_get_cpuid, we can use it to save lr modifing it with the

	 * following bl

	 */

	mov r0, lr

	bl	ll_get_coherency_base

	bl	ll_get_cpuid

	mov lr, r0

	add	r0, r1, #ARMADA_XP_CFB_CTL_REG_OFFSET

1:

	ldrex	r2, [r3]

	orr	r2, r2, r1

	strex	r0, r2, [r3]

	cmp	r0, #0

	ldrex	r2, [r0]

	orr	r2, r2, r3

	strex	r1, r2, [r0]

	cmp	r1, #0

	bne	1b



	dsb



	mov	r0, #0

	mov	pc, lr

ENDPROC(ll_set_cpu_coherent)

ENDPROC(ll_enable_coherency)





	.align 2

3:

arch/arm/mach-mvebu/headsmp.S

+4 −2
Original line number Diff line number Diff line
@@ -31,8 +31,10 @@ 
ENTRY(armada_xp_secondary_startup)

 ARM_BE8(setend	be )			@ go BE8 if entered LE



	/* Add CPU to coherency fabric */

	bl	ll_set_cpu_coherent

	bl	ll_add_cpu_to_smp_group



	bl	ll_enable_coherency



	b	secondary_startup



ENDPROC(armada_xp_secondary_startup)