diff options
Diffstat (limited to 'arch/arm/kvm/psci.c')
-rw-r--r-- | arch/arm/kvm/psci.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c new file mode 100644 index 000000000000..7ee5bb7a3667 --- /dev/null +++ b/arch/arm/kvm/psci.c | |||
@@ -0,0 +1,108 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2012 - ARM Ltd | ||
3 | * Author: Marc Zyngier <marc.zyngier@arm.com> | ||
4 | * | ||
5 | * This program is free software; you can redistribute it and/or modify | ||
6 | * it under the terms of the GNU General Public License version 2 as | ||
7 | * published by the Free Software Foundation. | ||
8 | * | ||
9 | * This program is distributed in the hope that it will be useful, | ||
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
12 | * GNU General Public License for more details. | ||
13 | * | ||
14 | * You should have received a copy of the GNU General Public License | ||
15 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | ||
16 | */ | ||
17 | |||
18 | #include <linux/kvm_host.h> | ||
19 | #include <linux/wait.h> | ||
20 | |||
21 | #include <asm/kvm_emulate.h> | ||
22 | #include <asm/kvm_psci.h> | ||
23 | |||
24 | /* | ||
25 | * This is an implementation of the Power State Coordination Interface | ||
26 | * as described in ARM document number ARM DEN 0022A. | ||
27 | */ | ||
28 | |||
29 | static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) | ||
30 | { | ||
31 | vcpu->arch.pause = true; | ||
32 | } | ||
33 | |||
34 | static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) | ||
35 | { | ||
36 | struct kvm *kvm = source_vcpu->kvm; | ||
37 | struct kvm_vcpu *vcpu; | ||
38 | wait_queue_head_t *wq; | ||
39 | unsigned long cpu_id; | ||
40 | phys_addr_t target_pc; | ||
41 | |||
42 | cpu_id = *vcpu_reg(source_vcpu, 1); | ||
43 | if (vcpu_mode_is_32bit(source_vcpu)) | ||
44 | cpu_id &= ~((u32) 0); | ||
45 | |||
46 | if (cpu_id >= atomic_read(&kvm->online_vcpus)) | ||
47 | return KVM_PSCI_RET_INVAL; | ||
48 | |||
49 | target_pc = *vcpu_reg(source_vcpu, 2); | ||
50 | |||
51 | vcpu = kvm_get_vcpu(kvm, cpu_id); | ||
52 | |||
53 | wq = kvm_arch_vcpu_wq(vcpu); | ||
54 | if (!waitqueue_active(wq)) | ||
55 | return KVM_PSCI_RET_INVAL; | ||
56 | |||
57 | kvm_reset_vcpu(vcpu); | ||
58 | |||
59 | /* Gracefully handle Thumb2 entry point */ | ||
60 | if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) { | ||
61 | target_pc &= ~((phys_addr_t) 1); | ||
62 | vcpu_set_thumb(vcpu); | ||
63 | } | ||
64 | |||
65 | *vcpu_pc(vcpu) = target_pc; | ||
66 | vcpu->arch.pause = false; | ||
67 | smp_mb(); /* Make sure the above is visible */ | ||
68 | |||
69 | wake_up_interruptible(wq); | ||
70 | |||
71 | return KVM_PSCI_RET_SUCCESS; | ||
72 | } | ||
73 | |||
74 | /** | ||
75 | * kvm_psci_call - handle PSCI call if r0 value is in range | ||
76 | * @vcpu: Pointer to the VCPU struct | ||
77 | * | ||
78 | * Handle PSCI calls from guests through traps from HVC or SMC instructions. | ||
79 | * The calling convention is similar to SMC calls to the secure world where | ||
80 | * the function number is placed in r0 and this function returns true if the | ||
81 | * function number specified in r0 is withing the PSCI range, and false | ||
82 | * otherwise. | ||
83 | */ | ||
84 | bool kvm_psci_call(struct kvm_vcpu *vcpu) | ||
85 | { | ||
86 | unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); | ||
87 | unsigned long val; | ||
88 | |||
89 | switch (psci_fn) { | ||
90 | case KVM_PSCI_FN_CPU_OFF: | ||
91 | kvm_psci_vcpu_off(vcpu); | ||
92 | val = KVM_PSCI_RET_SUCCESS; | ||
93 | break; | ||
94 | case KVM_PSCI_FN_CPU_ON: | ||
95 | val = kvm_psci_vcpu_on(vcpu); | ||
96 | break; | ||
97 | case KVM_PSCI_FN_CPU_SUSPEND: | ||
98 | case KVM_PSCI_FN_MIGRATE: | ||
99 | val = KVM_PSCI_RET_NI; | ||
100 | break; | ||
101 | |||
102 | default: | ||
103 | return false; | ||
104 | } | ||
105 | |||
106 | *vcpu_reg(vcpu, 0) = val; | ||
107 | return true; | ||
108 | } | ||