blob: c1d7db71a7269c622c11f181ec5929a5fa351a7f [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0-only */
* kexec for arm64
* Copyright (C) Linaro.
* Copyright (C) Huawei Futurewei Technologies.
#include <linux/kexec.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/kexec.h>
#include <asm/page.h>
#include <asm/sysreg.h>
* 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 coping 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
* control_code_page, a special page which has been set up to be preserved
* during the copy operation.
/* Setup the list loop variables. */
mov x18, x2 /* x18 = dtb address */
mov x17, x1 /* x17 = kimage_start */
mov x16, x0 /* x16 = kimage_head */
raw_dcache_line_size x15, x0 /* x15 = dcache line size */
mov x14, xzr /* x14 = entry ptr */
mov x13, xzr /* x13 = copy dest */
/* Clear the sctlr_el2 flags. */
mrs x0, CurrentEL
cmp x0, #CurrentEL_EL2 1f
mrs x0, sctlr_el2
ldr x1, =SCTLR_ELx_FLAGS
bic x0, x0, x1
msr sctlr_el2, x0
/* Check if the new image needs relocation. */
tbnz x16, IND_DONE_BIT, .Ldone
and x12, x16, PAGE_MASK /* x12 = addr */
/* Test the entry flags. */
tbz x16, IND_SOURCE_BIT, .Ltest_indirection
/* Invalidate dest page to PoC. */
mov x0, x13
add x20, x0, #PAGE_SIZE
sub x1, x15, #1
bic x0, x0, x1
2: dc ivac, x0
add x0, x0, x15
cmp x0, x20
b.lo 2b
dsb sy
mov x20, x13
mov x21, x12
copy_page x20, x21, x0, x1, x2, x3, x4, x5, x6, x7
/* dest += PAGE_SIZE */
add x13, x13, PAGE_SIZE
b .Lnext
tbz x16, IND_INDIRECTION_BIT, .Ltest_destination
/* ptr = addr */
mov x14, x12
b .Lnext
tbz x16, IND_DESTINATION_BIT, .Lnext
/* dest = addr */
mov x13, x12
/* entry = *ptr++ */
ldr x16, [x14], #8
/* while (!(entry & DONE)) */
tbz x16, IND_DONE_BIT, .Lloop
/* wait for writes from copy_page to finish */
dsb nsh
ic iallu
dsb nsh
/* Start new image. */
mov x0, x18
mov x1, xzr
mov x2, xzr
mov x3, xzr
br x17
.align 3 /* To keep the 64-bit values below naturally aligned. */
* arm64_relocate_new_kernel_size - Number of bytes to copy to the
* control_code_page.
.globl arm64_relocate_new_kernel_size
.quad .Lcopy_end - arm64_relocate_new_kernel