summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kvm/hyp-init.S
blob: 6b29d3d9e1f285c0f1e61c3509cfbaf99402ea86 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
/*
 * Copyright (C) 2012,2013 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/linkage.h>

#include <asm/assembler.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_mmu.h>
#include <asm/pgtable-hwdef.h>
#include <asm/sysreg.h>

	.text
	.pushsection	.hyp.idmap.text, "ax"

	.align	11

ENTRY(__kvm_hyp_init)
	ventry	__invalid		// Synchronous EL2t
	ventry	__invalid		// IRQ EL2t
	ventry	__invalid		// FIQ EL2t
	ventry	__invalid		// Error EL2t

	ventry	__invalid		// Synchronous EL2h
	ventry	__invalid		// IRQ EL2h
	ventry	__invalid		// FIQ EL2h
	ventry	__invalid		// Error EL2h

	ventry	__do_hyp_init		// Synchronous 64-bit EL1
	ventry	__invalid		// IRQ 64-bit EL1
	ventry	__invalid		// FIQ 64-bit EL1
	ventry	__invalid		// Error 64-bit EL1

	ventry	__invalid		// Synchronous 32-bit EL1
	ventry	__invalid		// IRQ 32-bit EL1
	ventry	__invalid		// FIQ 32-bit EL1
	ventry	__invalid		// Error 32-bit EL1

__invalid:
	b	.

	/*
	 * x0: HYP pgd
	 * x1: HYP stack
	 * x2: HYP vectors
	 */
__do_hyp_init:

	msr	ttbr0_el2, x0

	mrs	x4, tcr_el1
	ldr	x5, =TCR_EL2_MASK
	and	x4, x4, x5
	mov	x5, #TCR_EL2_RES1
	orr	x4, x4, x5

#ifndef CONFIG_ARM64_VA_BITS_48
	/*
	 * If we are running with VA_BITS < 48, we may be running with an extra
	 * level of translation in the ID map. This is only the case if system
	 * RAM is out of range for the currently configured page size and number
	 * of translation levels, in which case we will also need the extra
	 * level for the HYP ID map, or we won't be able to enable the EL2 MMU.
	 *
	 * However, at EL2, there is only one TTBR register, and we can't switch
	 * between translation tables *and* update TCR_EL2.T0SZ at the same
	 * time. Bottom line: we need the extra level in *both* our translation
	 * tables.
	 *
	 * So use the same T0SZ value we use for the ID map.
	 */
	ldr_l	x5, idmap_t0sz
	bfi	x4, x5, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH
#endif
	/*
	 * Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS bits in
	 * TCR_EL2.
	 */
	mrs	x5, ID_AA64MMFR0_EL1
	bfi	x4, x5, #16, #3

	msr	tcr_el2, x4

	mrs	x4, mair_el1
	msr	mair_el2, x4
	isb

	/* Invalidate the stale TLBs from Bootloader */
	tlbi	alle2
	dsb	sy

	mrs	x4, sctlr_el2
	and	x4, x4, #SCTLR_ELx_EE	// preserve endianness of EL2
	ldr	x5, =SCTLR_ELx_FLAGS
	orr	x4, x4, x5
	msr	sctlr_el2, x4
	isb

	/* Set the stack and new vectors */
	kern_hyp_va	x1
	mov	sp, x1
	kern_hyp_va	x2
	msr	vbar_el2, x2

	/* Hello, World! */
	eret
ENDPROC(__kvm_hyp_init)

	/*
	 * Reset kvm back to the hyp stub.
	 */
ENTRY(__kvm_hyp_reset)
	/* We're now in idmap, disable MMU */
	mrs	x0, sctlr_el2
	ldr	x1, =SCTLR_ELx_FLAGS
	bic	x0, x0, x1		// Clear SCTL_M and etc
	msr	sctlr_el2, x0
	isb

	/* Install stub vectors */
	adr_l	x0, __hyp_stub_vectors
	msr	vbar_el2, x0

	eret
ENDPROC(__kvm_hyp_reset)

	.ltorg

	.popsection