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ARM: mvebu: Split low level functions to manipulate HW coherency

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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: Gregory 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: Jason Cooper <jason@lakedaemon.net>
This commit is contained in:
Gregory CLEMENT 2014-04-14 17:10:08 +02:00 committed by Jason Cooper
parent 952f4ca79b
commit 2e8a5942f8
3 changed files with 71 additions and 35 deletions
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8
arch/arm/mach-mvebu/coherency.c
View File

@ -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();
}
/*

92
arch/arm/mach-mvebu/coherency_ll.S
View File

@ -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]
/* use physical address of the coherency register */
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]
/* use virtual address of the coherency register */
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
bne 1b
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
bne 1b
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:

6
arch/arm/mach-mvebu/headsmp.S
View File

@ -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)