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/*
* Based on arch/arm/include/asm/cacheflush.h
*
* Copyright (C) 1999-2002 Russell King.
* Copyright (C) 2012 ARM Ltd.
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <arch/asm.h>
#include <arch/cache_helpers.h>
/*
* Bring an ARMv8 processor we just gained control of (e.g. from IROM) into a
* known state regarding caches/SCTLR. Completely cleans and invalidates
* icache/dcache, disables MMU and dcache (if active), and enables unaligned
* accesses, icache and branch prediction (if inactive). Clobbers x4 and x5.
*/
ENTRY(arm_init_caches)
/* w4: SCTLR, return address: x8 (stay valid for the whole function) */
mov x8, x30
/* XXX: Assume that we always start running at EL3 */
mrs x4, sctlr_el3
/* FIXME: How to enable branch prediction on ARMv8? */
/* Flush and invalidate dcache */
mov x0, #DCCISW
bl flush_dcache_all
/* Deactivate MMU (0), Alignment Check (1) and DCache (2) */
and x4, x4, # ~(1 << 0) & ~(1 << 1) & ~(1 << 2)
/* Activate ICache (12) already for speed */
orr x4, x4, #(1 << 12)
msr sctlr_el3, x4
/* Invalidate icache and TLB for good measure */
ic iallu
tlbi alle3
dsb sy
isb
ret x8
ENDPROC(arm_init_caches)
/* Based on u-boot transition.S */
ENTRY(switch_el3_to_el2)
mov x0, #0x5b1 /* Non-secure EL0/EL1 | HVC | 64bit EL2 */
msr scr_el3, x0
msr cptr_el3, xzr /* Disable coprocessor traps to EL3 */
mov x0, #0x33ff
msr cptr_el2, x0 /* Disable coprocessor traps to EL2 */
/* Return to the EL2_SP2 mode from EL3 */
mov x0, sp
msr sp_el2, x0 /* Migrate SP */
mrs x0, vbar_el3
msr vbar_el2, x0 /* Migrate VBAR */
mrs x0, sctlr_el3
msr sctlr_el2, x0 /* Migrate SCTLR */
mov x0, #0x3c9
msr spsr_el3, x0 /* EL2_SP2 | D | A | I | F */
msr elr_el3, x30
eret
ENDPROC(switch_el3_to_el2)
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