linux_dsm_epyc7002/arch/arm/mach-mvebu/coherency_ll.S
Gregory CLEMENT 009f13159b arm: mvebu: Add support for coherency fabric in mach-mvebu
The Armada 370 and Armada XP SOCs have a coherency fabric unit which
is responsible for ensuring hardware coherency between all CPUs and
between CPUs and I/O masters. This patch provides the basic support
needed for SMP.

Signed-off-by: Yehuda Yitschak <yehuday@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
2012-11-21 16:49:06 +01:00

50 lines
1.2 KiB
ArmAsm

/*
* 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
.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
/* Add CPU to SMP group - Atomic */
add r3, r0, #ARMADA_XP_CFB_CTL_REG_OFFSET
ldr r2, [r3]
orr r2, r2, r1
str r2, [r3]
/* Enable coherency on CPU - Atomic */
add r3, r0, #ARMADA_XP_CFB_CFG_REG_OFFSET
ldr r2, [r3]
orr r2, r2, r1
str r2, [r3]
dsb
mov r0, #0
mov pc, lr
ENDPROC(ll_set_cpu_coherent)