kernel/arch/arm/mach-shmobile/headsmp-scu.S
2024-07-22 17:22:30 +08:00

32 lines
808 B
ArmAsm

/* SPDX-License-Identifier: GPL-2.0+
*
* Shared SCU setup for mach-shmobile
*
* Copyright (C) 2012 Bastian Hecht
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/memory.h>
/*
* Boot code for secondary CPUs.
*
* First we turn on L1 cache coherency for our CPU. Then we jump to
* secondary_startup that invalidates the cache and hands over control
* to the common ARM startup code.
*/
ENTRY(shmobile_boot_scu)
@ r0 = SCU base address
mrc p15, 0, r1, c0, c0, 5 @ read MPIDR
and r1, r1, #3 @ mask out cpu ID
lsl r1, r1, #3 @ we will shift by cpu_id * 8 bits
ldr r2, [r0, #8] @ SCU Power Status Register
mov r3, #3
lsl r3, r3, r1
bic r2, r2, r3 @ Clear bits of our CPU (Run Mode)
str r2, [r0, #8] @ write back
b secondary_startup
ENDPROC(shmobile_boot_scu)