xref: /linux/arch/arm64/kernel/hyp-stub.S (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1/*
2 * Hypervisor stub
3 *
4 * Copyright (C) 2012 ARM Ltd.
5 * Author:	Marc Zyngier <marc.zyngier@arm.com>
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 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/init.h>
21#include <linux/linkage.h>
22
23#include <asm/assembler.h>
24#include <asm/ptrace.h>
25#include <asm/virt.h>
26
27	.text
28	.align 11
29
30ENTRY(__hyp_stub_vectors)
31	ventry	el2_sync_invalid		// Synchronous EL2t
32	ventry	el2_irq_invalid			// IRQ EL2t
33	ventry	el2_fiq_invalid			// FIQ EL2t
34	ventry	el2_error_invalid		// Error EL2t
35
36	ventry	el2_sync_invalid		// Synchronous EL2h
37	ventry	el2_irq_invalid			// IRQ EL2h
38	ventry	el2_fiq_invalid			// FIQ EL2h
39	ventry	el2_error_invalid		// Error EL2h
40
41	ventry	el1_sync			// Synchronous 64-bit EL1
42	ventry	el1_irq_invalid			// IRQ 64-bit EL1
43	ventry	el1_fiq_invalid			// FIQ 64-bit EL1
44	ventry	el1_error_invalid		// Error 64-bit EL1
45
46	ventry	el1_sync_invalid		// Synchronous 32-bit EL1
47	ventry	el1_irq_invalid			// IRQ 32-bit EL1
48	ventry	el1_fiq_invalid			// FIQ 32-bit EL1
49	ventry	el1_error_invalid		// Error 32-bit EL1
50ENDPROC(__hyp_stub_vectors)
51
52	.align 11
53
54el1_sync:
55	mrs	x1, esr_el2
56	lsr	x1, x1, #26
57	cmp	x1, #0x16
58	b.ne	2f				// Not an HVC trap
59	cbz	x0, 1f
60	msr	vbar_el2, x0			// Set vbar_el2
61	b	2f
621:	mrs	x0, vbar_el2			// Return vbar_el2
632:	eret
64ENDPROC(el1_sync)
65
66.macro invalid_vector	label
67\label:
68	b \label
69ENDPROC(\label)
70.endm
71
72	invalid_vector	el2_sync_invalid
73	invalid_vector	el2_irq_invalid
74	invalid_vector	el2_fiq_invalid
75	invalid_vector	el2_error_invalid
76	invalid_vector	el1_sync_invalid
77	invalid_vector	el1_irq_invalid
78	invalid_vector	el1_fiq_invalid
79	invalid_vector	el1_error_invalid
80
81/*
82 * __hyp_set_vectors: Call this after boot to set the initial hypervisor
83 * vectors as part of hypervisor installation.  On an SMP system, this should
84 * be called on each CPU.
85 *
86 * x0 must be the physical address of the new vector table, and must be
87 * 2KB aligned.
88 *
89 * Before calling this, you must check that the stub hypervisor is installed
90 * everywhere, by waiting for any secondary CPUs to be brought up and then
91 * checking that is_hyp_mode_available() is true.
92 *
93 * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or
94 * something else went wrong... in such cases, trying to install a new
95 * hypervisor is unlikely to work as desired.
96 *
97 * When you call into your shiny new hypervisor, sp_el2 will contain junk,
98 * so you will need to set that to something sensible at the new hypervisor's
99 * initialisation entry point.
100 */
101
102ENTRY(__hyp_get_vectors)
103	mov	x0, xzr
104	// fall through
105ENTRY(__hyp_set_vectors)
106	hvc	#0
107	ret
108ENDPROC(__hyp_get_vectors)
109ENDPROC(__hyp_set_vectors)
110