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/*
* Coherency fabric: low level functions
*
* Copyright (C) 2012 Marvell
*
* Gregory CLEMENT <gregory.clement@free-electrons.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*
* This file implements the assembly function to add a CPU to the
* coherency fabric. This function is called by each of the secondary
* CPUs during their early boot in an SMP kernel, this why this
* function have to callable from assembly. It can also be called by a
* primary CPU from C code during its boot.
*/
#include <linux/linkage.h>
#define ARMADA_XP_CFB_CTL_REG_OFFSET 0x0
#define ARMADA_XP_CFB_CFG_REG_OFFSET 0x4
#include <asm/assembler.h>
.text
/*
* r0: Coherency fabric base register address
* r1: HW CPU id
*/
ENTRY(ll_set_cpu_coherent)
/* Create bit by cpu index */
mov r3, #(1 << 24)
lsl r1, r3, r1
ARM_BE8(rev r1, r1)
/* Add CPU to SMP group - Atomic */
add r3, r0, #ARMADA_XP_CFB_CTL_REG_OFFSET
1:
ldrex r2, [r3]
orr r2, r2, r1
strex r0, r2, [r3]
cmp r0, #0
bne 1b
/* Enable coherency on CPU - Atomic */
add r3, r3, #ARMADA_XP_CFB_CFG_REG_OFFSET
1:
ldrex r2, [r3]
orr r2, r2, r1
strex r0, r2, [r3]
cmp r0, #0
bne 1b
dsb
mov r0, #0
mov pc, lr
ENDPROC(ll_set_cpu_coherent)
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