pv-fixup-asm.S
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2015 Russell King
*
* This assembly is required to safely remap the physical address space
* for Keystone 2
*/
#include <linux/linkage.h>
#include <linux/pgtable.h>
#include <asm/asm-offsets.h>
#include <asm/cp15.h>
#include <asm/memory.h>
.section ".idmap.text", "ax"
#define L1_ORDER 3
#define L2_ORDER 3
ENTRY(lpae_pgtables_remap_asm)
stmfd sp!, {r4-r8, lr}
mrc p15, 0, r8, c1, c0, 0 @ read control reg
bic ip, r8, #CR_M @ disable caches and MMU
mcr p15, 0, ip, c1, c0, 0
dsb
isb
/* Update level 2 entries covering the kernel */
ldr r6, =(_end - 1)
add r7, r2, #0x1000
add r6, r7, r6, lsr #SECTION_SHIFT - L2_ORDER
add r7, r7, #KERNEL_OFFSET >> (SECTION_SHIFT - L2_ORDER)
1: ldrd r4, r5, [r7]
adds r4, r4, r0
adc r5, r5, r1
strd r4, r5, [r7], #1 << L2_ORDER
cmp r7, r6
bls 1b
/* Update level 2 entries for the boot data */
add r7, r2, #0x1000
movw r3, #FDT_FIXED_BASE >> (SECTION_SHIFT - L2_ORDER)
add r7, r7, r3
ldrd r4, r5, [r7]
adds r4, r4, r0
adc r5, r5, r1
strd r4, r5, [r7], #1 << L2_ORDER
ldrd r4, r5, [r7]
adds r4, r4, r0
adc r5, r5, r1
strd r4, r5, [r7]
/* Update level 1 entries */
mov r6, #4
mov r7, r2
2: ldrd r4, r5, [r7]
adds r4, r4, r0
adc r5, r5, r1
strd r4, r5, [r7], #1 << L1_ORDER
subs r6, r6, #1
bne 2b
mrrc p15, 0, r4, r5, c2 @ read TTBR0
adds r4, r4, r0 @ update physical address
adc r5, r5, r1
mcrr p15, 0, r4, r5, c2 @ write back TTBR0
mrrc p15, 1, r4, r5, c2 @ read TTBR1
adds r4, r4, r0 @ update physical address
adc r5, r5, r1
mcrr p15, 1, r4, r5, c2 @ write back TTBR1
dsb
mov ip, #0
mcr p15, 0, ip, c7, c5, 0 @ I+BTB cache invalidate
mcr p15, 0, ip, c8, c7, 0 @ local_flush_tlb_all()
dsb
isb
mcr p15, 0, r8, c1, c0, 0 @ re-enable MMU
dsb
isb
ldmfd sp!, {r4-r8, pc}
ENDPROC(lpae_pgtables_remap_asm)