linux/arch/arm/mach-shmobile/headsmp.S

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/*
* SMP support for R-Mobile / SH-Mobile
*
* Copyright (C) 2010 Magnus Damm
* Copyright (C) 2010 Takashi Yoshii
*
* Based on vexpress, Copyright (c) 2003 ARM Limited, All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/memory.h>
__CPUINIT
/* Cache invalidation nicked from arch/arm/mach-imx/head-v7.S, thanks!
*
* The secondary kernel init calls v7_flush_dcache_all before it enables
* the L1; however, the L1 comes out of reset in an undefined state, so
* the clean + invalidate performed by v7_flush_dcache_all causes a bunch
* of cache lines with uninitialized data and uninitialized tags to get
* written out to memory, which does really unpleasant things to the main
* processor. We fix this by performing an invalidate, rather than a
* clean + invalidate, before jumping into the kernel.
*
* This funciton is cloned from arch/arm/mach-tegra/headsmp.S, and needs
* to be called for both secondary cores startup and primary core resume
* procedures. Ideally, it should be moved into arch/arm/mm/cache-v7.S.
*/
ENTRY(v7_invalidate_l1)
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
mcr p15, 2, r0, c0, c0, 0
mrc p15, 1, r0, c0, c0, 0
ldr r1, =0x7fff
and r2, r1, r0, lsr #13
ldr r1, =0x3ff
and r3, r1, r0, lsr #3 @ NumWays - 1
add r2, r2, #1 @ NumSets
and r0, r0, #0x7
add r0, r0, #4 @ SetShift
clz r1, r3 @ WayShift
add r4, r3, #1 @ NumWays
1: sub r2, r2, #1 @ NumSets--
mov r3, r4 @ Temp = NumWays
2: subs r3, r3, #1 @ Temp--
mov r5, r3, lsl r1
mov r6, r2, lsl r0
orr r5, r5, r6 @ Reg = (Temp<<WayShift)|(NumSets<<SetShift)
mcr p15, 0, r5, c7, c6, 2
bgt 2b
cmp r2, #0
bgt 1b
dsb
isb
mov pc, lr
ENDPROC(v7_invalidate_l1)
ENTRY(shmobile_invalidate_start)
bl v7_invalidate_l1
b secondary_startup
ENDPROC(shmobile_invalidate_start)
/*
* Reset vector for secondary CPUs.
* This will be mapped at address 0 by SBAR register.
* We need _long_ jump to the physical address.
*/
.align 12
ENTRY(shmobile_secondary_vector)
ldr pc, 1f
1: .long shmobile_invalidate_start - PAGE_OFFSET + PLAT_PHYS_OFFSET
ENDPROC(shmobile_secondary_vector)