[linux-2.6-block.git] / arch / arm64 / kernel / relocate_kernel.S

/*
 * kexec for arm64
 *
 * Copyright (C) Linaro.
 * Copyright (C) Huawei Futurewei Technologies.
 *
 * 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.
 */

#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.
 */
ENTRY(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
	ldr	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

ENDPROC(arm64_relocate_new_kernel)

.ltorg

.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
Commit	Line	Data
d28f6df1 GL	1	/*
	2	* kexec for arm64
	3	*
	4	* Copyright (C) Linaro.
	5	* Copyright (C) Huawei Futurewei Technologies.
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
	12	#include <linux/kexec.h>
	13	#include <linux/linkage.h>
	14
	15	#include <asm/assembler.h>
	16	#include <asm/kexec.h>
	17	#include <asm/page.h>
	18	#include <asm/sysreg.h>
	19
	20	/*
	21	* arm64_relocate_new_kernel - Put a 2nd stage image in place and boot it.
	22	*
	23	* The memory that the old kernel occupies may be overwritten when coping the
	24	* new image to its final location. To assure that the
	25	* arm64_relocate_new_kernel routine which does that copy is not overwritten,
	26	* all code and data needed by arm64_relocate_new_kernel must be between the
	27	* symbols arm64_relocate_new_kernel and arm64_relocate_new_kernel_end. The
	28	* machine_kexec() routine will copy arm64_relocate_new_kernel to the kexec
	29	* control_code_page, a special page which has been set up to be preserved
	30	* during the copy operation.
	31	*/
	32	ENTRY(arm64_relocate_new_kernel)
	33
	34	/* Setup the list loop variables. */
4c9e7e64	35	mov x18, x2 /* x18 = dtb address */
d28f6df1 GL	36	mov x17, x1 /* x17 = kimage_start */
d28f6df1 GL	37	mov x16, x0 /* x16 = kimage_head */
072f0a63	38	raw_dcache_line_size x15, x0 /* x15 = dcache line size */
d28f6df1 GL	39	mov x14, xzr /* x14 = entry ptr */
	40	mov x13, xzr /* x13 = copy dest */
	41
	42	/* Clear the sctlr_el2 flags. */
	43	mrs x0, CurrentEL
	44	cmp x0, #CurrentEL_EL2
	45	b.ne 1f
	46	mrs x0, sctlr_el2
	47	ldr x1, =SCTLR_ELx_FLAGS
	48	bic x0, x0, x1
932b50c7	49	pre_disable_mmu_workaround
d28f6df1 GL	50	msr sctlr_el2, x0
	51	isb
	52	1:
	53
	54	/* Check if the new image needs relocation. */
	55	tbnz x16, IND_DONE_BIT, .Ldone
	56
	57	.Lloop:
	58	and x12, x16, PAGE_MASK /* x12 = addr */
	59
	60	/* Test the entry flags. */
	61	.Ltest_source:
	62	tbz x16, IND_SOURCE_BIT, .Ltest_indirection
	63
	64	/* Invalidate dest page to PoC. */
	65	mov x0, x13
	66	add x20, x0, #PAGE_SIZE
	67	sub x1, x15, #1
	68	bic x0, x0, x1
	69	2: dc ivac, x0
	70	add x0, x0, x15
	71	cmp x0, x20
	72	b.lo 2b
	73	dsb sy
	74
	75	mov x20, x13
	76	mov x21, x12
	77	copy_page x20, x21, x0, x1, x2, x3, x4, x5, x6, x7
	78
	79	/* dest += PAGE_SIZE */
	80	add x13, x13, PAGE_SIZE
	81	b .Lnext
	82
	83	.Ltest_indirection:
	84	tbz x16, IND_INDIRECTION_BIT, .Ltest_destination
	85
	86	/* ptr = addr */
	87	mov x14, x12
	88	b .Lnext
	89
	90	.Ltest_destination:
	91	tbz x16, IND_DESTINATION_BIT, .Lnext
	92
	93	/* dest = addr */
	94	mov x13, x12
	95
	96	.Lnext:
	97	/* entry = ptr++ /
	98	ldr x16, [x14], #8
	99
	100	/* while (!(entry & DONE)) */
	101	tbz x16, IND_DONE_BIT, .Lloop
	102
	103	.Ldone:
	104	/* wait for writes from copy_page to finish */
	105	dsb nsh
	106	ic iallu
	107	dsb nsh
	108	isb
	109
	110	/* Start new image. */
4c9e7e64	111	mov x0, x18
d28f6df1 GL	112	mov x1, xzr
	113	mov x2, xzr
	114	mov x3, xzr
	115	br x17
	116
	117	ENDPROC(arm64_relocate_new_kernel)
	118
	119	.ltorg
	120
	121	.align 3 /* To keep the 64-bit values below naturally aligned. */
	122
	123	.Lcopy_end:
	124	.org KEXEC_CONTROL_PAGE_SIZE
	125
	126	/*
	127	* arm64_relocate_new_kernel_size - Number of bytes to copy to the
	128	* control_code_page.
	129	*/
	130	.globl arm64_relocate_new_kernel_size
	131	arm64_relocate_new_kernel_size:
	132	.quad .Lcopy_end - arm64_relocate_new_kernel