/* SPDX-License-Identifier: GPL-2.0-only */
/*
* kexec for arm64
*
* Copyright (C) Linaro.
* Copyright (C) Huawei Futurewei Technologies.
* Copyright (C) 2021, Microsoft Corporation.
* Pasha Tatashin <pasha.tatashin@soleen.com>
*/
#include <linux/kexec.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/kexec.h>
#include <asm/page.h>
#include <asm/sysreg.h>
#include <asm/virt.h>
.macro turn_off_mmu tmp1, tmp2
mov_q \tmp1, INIT_SCTLR_EL1_MMU_OFF
pre_disable_mmu_workaround
msr sctlr_el1, \tmp1
isb
.endm
.
section ".kexec_relocate.text",
"ax"
/*
* arm64_relocate_new_kernel - Put a 2nd stage image in place and boot it.
*
* The memory that the old kernel occupies may be overwritten when copying the
* new image to its final location. To assure that the
* arm64_relocate_new_kernel routine which does that copy is not overwritten,
* all code and data needed by arm64_relocate_new_kernel must be between the
* symbols arm64_relocate_new_kernel and arm64_relocate_new_kernel_end. The
* machine_kexec() routine will copy arm64_relocate_new_kernel to the kexec
* safe memory that has been set up to be preserved during the copy operation.
*/
SYM_CODE_START(arm64_relocate_new_kernel)
/*
* The kimage structure isn't allocated specially and may be clobbered
* during relocation. We must load any values we need from it prior to
* any relocation occurring.
*/
ldr x28, [x0, #KIMAGE_START]
ldr x27, [x0, #KIMAGE_ARCH_EL2_VECTORS]
ldr x26, [x0, #KIMAGE_ARCH_DTB_MEM]
/* Setup the list loop variables. */
ldr x18, [x0, #KIMAGE_ARCH_ZERO_PAGE]
/* x18 = zero page for BBM */
ldr x17, [x0, #KIMAGE_ARCH_TTBR1]
/* x17 = linear map copy */
ldr x16, [x0, #KIMAGE_HEAD]
/* x16 = kimage_head */
ldr x22, [x0, #KIMAGE_ARCH_PHYS_OFFSET]
/* x22 phys_offset */
raw_dcache_line_size x15, x1
/* x15 = dcache line size */
break_before_make_ttbr_switch x18, x17, x1, x2
/* set linear map */
.Lloop:
and x12, x16, PAGE_MASK
/* x12 = addr */
sub x12, x12, x22
/* Convert x12 to virt */
/* Test the entry flags. */
.Ltest_source:
tbz x16, IND_SOURCE_BIT, .Ltest_indirection
/* Invalidate dest page to PoC. */
mov x19, x13
copy_page x13, x12, x1, x2, x3, x4, x5, x6, x7, x8
add x1, x19, #PAGE_SIZE
dcache_by_myline_op civac, sy, x19, x1, x15, x20
b .Lnext
.Ltest_indirection:
tbz x16, IND_INDIRECTION_BIT, .Ltest_destination
mov x14, x12
/* ptr = addr */
b .Lnext
.Ltest_destination:
tbz x16, IND_DESTINATION_BIT, .Lnext
mov x13, x12
/* dest = addr */
.Lnext:
ldr x16, [x14], #8
/* entry = *ptr++ */
tbz x16, IND_DONE_BIT, .Lloop
/* while (!(entry & DONE)) */
/* wait for writes from copy_page to finish */
dsb nsh
ic iallu
dsb nsh
isb
turn_off_mmu x12, x13
/* Start new image. */
cbz x27, .Lel1
mov x1, x28
/* kernel entry point */
mov x2, x26
/* dtb address */
mov x3, xzr
mov x4, xzr
mov x0, #HVC_SOFT_RESTART
hvc #0
/* Jumps from el2 */
.Lel1:
mov x0, x26
/* dtb address */
mov x1, xzr
mov x2, xzr
mov x3, xzr
br x28
/* Jumps from el1 */
SYM_CODE_END(arm64_relocate_new_kernel)
