1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * kexec for arm64
4 *
5 * Copyright (C) Linaro.
6 * Copyright (C) Huawei Futurewei Technologies.
7 * Copyright (C) 2021, Microsoft Corporation.
8 * Pasha Tatashin <pasha.tatashin@soleen.com>
9 */
10
11#include <linux/kexec.h>
12#include <linux/linkage.h>
13
14#include <asm/assembler.h>
15#include <asm/kexec.h>
16#include <asm/page.h>
17#include <asm/sysreg.h>
18#include <asm/virt.h>
19
20.macro turn_off_mmu tmp1, tmp2
21	mov_q   \tmp1, INIT_SCTLR_EL1_MMU_OFF
22	pre_disable_mmu_workaround
23	msr	sctlr_el1, \tmp1
24	isb
25.endm
26
27.section    ".kexec_relocate.text", "ax"
28/*
29 * arm64_relocate_new_kernel - Put a 2nd stage image in place and boot it.
30 *
31 * The memory that the old kernel occupies may be overwritten when copying the
32 * new image to its final location.  To assure that the
33 * arm64_relocate_new_kernel routine which does that copy is not overwritten,
34 * all code and data needed by arm64_relocate_new_kernel must be between the
35 * symbols arm64_relocate_new_kernel and arm64_relocate_new_kernel_end.  The
36 * machine_kexec() routine will copy arm64_relocate_new_kernel to the kexec
37 * safe memory that has been set up to be preserved during the copy operation.
38 */
39SYM_CODE_START(arm64_relocate_new_kernel)
40	/*
41	 * The kimage structure isn't allocated specially and may be clobbered
42	 * during relocation. We must load any values we need from it prior to
43	 * any relocation occurring.
44	 */
45	ldr	x28, [x0, #KIMAGE_START]
46	ldr	x27, [x0, #KIMAGE_ARCH_EL2_VECTORS]
47	ldr	x26, [x0, #KIMAGE_ARCH_DTB_MEM]
48
49	/* Setup the list loop variables. */
50	ldr	x18, [x0, #KIMAGE_ARCH_ZERO_PAGE] /* x18 = zero page for BBM */
51	ldr	x17, [x0, #KIMAGE_ARCH_TTBR1]	/* x17 = linear map copy */
52	ldr	x16, [x0, #KIMAGE_HEAD]		/* x16 = kimage_head */
53	ldr	x22, [x0, #KIMAGE_ARCH_PHYS_OFFSET]	/* x22 phys_offset */
54	raw_dcache_line_size x15, x1		/* x15 = dcache line size */
55	break_before_make_ttbr_switch	x18, x17, x1, x2 /* set linear map */
56.Lloop:
57	and	x12, x16, PAGE_MASK		/* x12 = addr */
58	sub	x12, x12, x22			/* Convert x12 to virt */
59	/* Test the entry flags. */
60.Ltest_source:
61	tbz	x16, IND_SOURCE_BIT, .Ltest_indirection
62
63	/* Invalidate dest page to PoC. */
64	mov	x19, x13
65	copy_page x13, x12, x1, x2, x3, x4, x5, x6, x7, x8
66	add	x1, x19, #PAGE_SIZE
67	dcache_by_myline_op civac, sy, x19, x1, x15, x20
68	b	.Lnext
69.Ltest_indirection:
70	tbz	x16, IND_INDIRECTION_BIT, .Ltest_destination
71	mov	x14, x12			/* ptr = addr */
72	b	.Lnext
73.Ltest_destination:
74	tbz	x16, IND_DESTINATION_BIT, .Lnext
75	mov	x13, x12			/* dest = addr */
76.Lnext:
77	ldr	x16, [x14], #8			/* entry = *ptr++ */
78	tbz	x16, IND_DONE_BIT, .Lloop	/* while (!(entry & DONE)) */
79	/* wait for writes from copy_page to finish */
80	dsb	nsh
81	ic	iallu
82	dsb	nsh
83	isb
84	turn_off_mmu x12, x13
85
86	/* Start new image. */
87	cbz	x27, .Lel1
88	mov	x1, x28				/* kernel entry point */
89	mov	x2, x26				/* dtb address */
90	mov	x3, xzr
91	mov	x4, xzr
92	mov     x0, #HVC_SOFT_RESTART
93	hvc	#0				/* Jumps from el2 */
94.Lel1:
95	mov	x0, x26				/* dtb address */
96	mov	x1, xzr
97	mov	x2, xzr
98	mov	x3, xzr
99	br	x28				/* Jumps from el1 */
100SYM_CODE_END(arm64_relocate_new_kernel)
101