1/*
2 * Copyright (C) 2012,2013 - ARM Ltd
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
4 *
5 * Derived from arch/arm/kvm/reset.c
6 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
7 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License, version 2, as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
20 */
21
22#include <linux/errno.h>
23#include <linux/kvm_host.h>
24#include <linux/kvm.h>
25
26#include <kvm/arm_arch_timer.h>
27
28#include <asm/cputype.h>
29#include <asm/ptrace.h>
30#include <asm/kvm_arm.h>
31#include <asm/kvm_coproc.h>
32
33/*
34 * ARMv8 Reset Values
35 */
36static const struct kvm_regs default_regs_reset = {
37	.regs.pstate = (PSR_MODE_EL1h | PSR_A_BIT | PSR_I_BIT |
38			PSR_F_BIT | PSR_D_BIT),
39};
40
41static const struct kvm_regs default_regs_reset32 = {
42	.regs.pstate = (COMPAT_PSR_MODE_SVC | COMPAT_PSR_A_BIT |
43			COMPAT_PSR_I_BIT | COMPAT_PSR_F_BIT),
44};
45
46static const struct kvm_irq_level default_vtimer_irq = {
47	.irq	= 27,
48	.level	= 1,
49};
50
51static bool cpu_has_32bit_el1(void)
52{
53	u64 pfr0;
54
55	pfr0 = read_cpuid(ID_AA64PFR0_EL1);
56	return !!(pfr0 & 0x20);
57}
58
59int kvm_arch_dev_ioctl_check_extension(long ext)
60{
61	int r;
62
63	switch (ext) {
64	case KVM_CAP_ARM_EL1_32BIT:
65		r = cpu_has_32bit_el1();
66		break;
67	default:
68		r = 0;
69	}
70
71	return r;
72}
73
74/**
75 * kvm_reset_vcpu - sets core registers and sys_regs to reset value
76 * @vcpu: The VCPU pointer
77 *
78 * This function finds the right table above and sets the registers on
79 * the virtual CPU struct to their architectually defined reset
80 * values.
81 */
82int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
83{
84	const struct kvm_irq_level *cpu_vtimer_irq;
85	const struct kvm_regs *cpu_reset;
86
87	switch (vcpu->arch.target) {
88	default:
89		if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
90			if (!cpu_has_32bit_el1())
91				return -EINVAL;
92			cpu_reset = &default_regs_reset32;
93		} else {
94			cpu_reset = &default_regs_reset;
95		}
96
97		cpu_vtimer_irq = &default_vtimer_irq;
98		break;
99	}
100
101	/* Reset core registers */
102	memcpy(vcpu_gp_regs(vcpu), cpu_reset, sizeof(*cpu_reset));
103
104	/* Reset system registers */
105	kvm_reset_sys_regs(vcpu);
106
107	/* Reset timer */
108	kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq);
109
110	return 0;
111}
112