linux/arch/arm64/kernel/relocate_kernel.S
Mark Brown 0343a7e463 arm64: kernel: Convert to modern annotations for assembly functions
In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These replace ENTRY and
ENDPROC and also add a new annotation for static functions which previously
had no ENTRY equivalent. Update the annotations in the core kernel code to
the new macros.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20200501115430.37315-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-04 12:46:03 +01:00

128 lines
2.8 KiB
ArmAsm

/* 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.
*/
SYM_CODE_START(arm64_relocate_new_kernel)
/* 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
b.ne 1f
mrs x0, sctlr_el2
mov_q x1, SCTLR_ELx_FLAGS
bic x0, x0, x1
pre_disable_mmu_workaround
msr sctlr_el2, x0
isb
1:
/* Check if the new image needs relocation. */
tbnz x16, IND_DONE_BIT, .Ldone
.Lloop:
and x12, x16, PAGE_MASK /* x12 = addr */
/* Test the entry flags. */
.Ltest_source:
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
.Ltest_indirection:
tbz x16, IND_INDIRECTION_BIT, .Ltest_destination
/* ptr = addr */
mov x14, x12
b .Lnext
.Ltest_destination:
tbz x16, IND_DESTINATION_BIT, .Lnext
/* dest = addr */
mov x13, x12
.Lnext:
/* entry = *ptr++ */
ldr x16, [x14], #8
/* while (!(entry & DONE)) */
tbz x16, IND_DONE_BIT, .Lloop
.Ldone:
/* wait for writes from copy_page to finish */
dsb nsh
ic iallu
dsb nsh
isb
/* Start new image. */
mov x0, x18
mov x1, xzr
mov x2, xzr
mov x3, xzr
br x17
SYM_CODE_END(arm64_relocate_new_kernel)
.align 3 /* To keep the 64-bit values below naturally aligned. */
.Lcopy_end:
.org KEXEC_CONTROL_PAGE_SIZE
/*
* arm64_relocate_new_kernel_size - Number of bytes to copy to the
* control_code_page.
*/
.globl arm64_relocate_new_kernel_size
arm64_relocate_new_kernel_size:
.quad .Lcopy_end - arm64_relocate_new_kernel