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1a89dd91 MZ |
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, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
17 | */ | |
18 | ||
19 | #include <linux/kvm.h> | |
20 | #include <linux/kvm_host.h> | |
21 | #include <linux/interrupt.h> | |
22 | #include <linux/io.h> | |
23 | #include <asm/kvm_emulate.h> | |
24 | ||
25 | #define ACCESS_READ_VALUE (1 << 0) | |
26 | #define ACCESS_READ_RAZ (0 << 0) | |
27 | #define ACCESS_READ_MASK(x) ((x) & (1 << 0)) | |
28 | #define ACCESS_WRITE_IGNORED (0 << 1) | |
29 | #define ACCESS_WRITE_SETBIT (1 << 1) | |
30 | #define ACCESS_WRITE_CLEARBIT (2 << 1) | |
31 | #define ACCESS_WRITE_VALUE (3 << 1) | |
32 | #define ACCESS_WRITE_MASK(x) ((x) & (3 << 1)) | |
33 | ||
34 | static u32 mmio_data_read(struct kvm_exit_mmio *mmio, u32 mask) | |
35 | { | |
36 | return *((u32 *)mmio->data) & mask; | |
37 | } | |
38 | ||
39 | static void mmio_data_write(struct kvm_exit_mmio *mmio, u32 mask, u32 value) | |
40 | { | |
41 | *((u32 *)mmio->data) = value & mask; | |
42 | } | |
43 | ||
44 | /** | |
45 | * vgic_reg_access - access vgic register | |
46 | * @mmio: pointer to the data describing the mmio access | |
47 | * @reg: pointer to the virtual backing of vgic distributor data | |
48 | * @offset: least significant 2 bits used for word offset | |
49 | * @mode: ACCESS_ mode (see defines above) | |
50 | * | |
51 | * Helper to make vgic register access easier using one of the access | |
52 | * modes defined for vgic register access | |
53 | * (read,raz,write-ignored,setbit,clearbit,write) | |
54 | */ | |
55 | static void vgic_reg_access(struct kvm_exit_mmio *mmio, u32 *reg, | |
56 | phys_addr_t offset, int mode) | |
57 | { | |
58 | int word_offset = (offset & 3) * 8; | |
59 | u32 mask = (1UL << (mmio->len * 8)) - 1; | |
60 | u32 regval; | |
61 | ||
62 | /* | |
63 | * Any alignment fault should have been delivered to the guest | |
64 | * directly (ARM ARM B3.12.7 "Prioritization of aborts"). | |
65 | */ | |
66 | ||
67 | if (reg) { | |
68 | regval = *reg; | |
69 | } else { | |
70 | BUG_ON(mode != (ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED)); | |
71 | regval = 0; | |
72 | } | |
73 | ||
74 | if (mmio->is_write) { | |
75 | u32 data = mmio_data_read(mmio, mask) << word_offset; | |
76 | switch (ACCESS_WRITE_MASK(mode)) { | |
77 | case ACCESS_WRITE_IGNORED: | |
78 | return; | |
79 | ||
80 | case ACCESS_WRITE_SETBIT: | |
81 | regval |= data; | |
82 | break; | |
83 | ||
84 | case ACCESS_WRITE_CLEARBIT: | |
85 | regval &= ~data; | |
86 | break; | |
87 | ||
88 | case ACCESS_WRITE_VALUE: | |
89 | regval = (regval & ~(mask << word_offset)) | data; | |
90 | break; | |
91 | } | |
92 | *reg = regval; | |
93 | } else { | |
94 | switch (ACCESS_READ_MASK(mode)) { | |
95 | case ACCESS_READ_RAZ: | |
96 | regval = 0; | |
97 | /* fall through */ | |
98 | ||
99 | case ACCESS_READ_VALUE: | |
100 | mmio_data_write(mmio, mask, regval >> word_offset); | |
101 | } | |
102 | } | |
103 | } | |
104 | ||
105 | /* | |
106 | * I would have liked to use the kvm_bus_io_*() API instead, but it | |
107 | * cannot cope with banked registers (only the VM pointer is passed | |
108 | * around, and we need the vcpu). One of these days, someone please | |
109 | * fix it! | |
110 | */ | |
111 | struct mmio_range { | |
112 | phys_addr_t base; | |
113 | unsigned long len; | |
114 | bool (*handle_mmio)(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio, | |
115 | phys_addr_t offset); | |
116 | }; | |
117 | ||
118 | static const struct mmio_range vgic_ranges[] = { | |
119 | {} | |
120 | }; | |
121 | ||
122 | static const | |
123 | struct mmio_range *find_matching_range(const struct mmio_range *ranges, | |
124 | struct kvm_exit_mmio *mmio, | |
125 | phys_addr_t base) | |
126 | { | |
127 | const struct mmio_range *r = ranges; | |
128 | phys_addr_t addr = mmio->phys_addr - base; | |
129 | ||
130 | while (r->len) { | |
131 | if (addr >= r->base && | |
132 | (addr + mmio->len) <= (r->base + r->len)) | |
133 | return r; | |
134 | r++; | |
135 | } | |
136 | ||
137 | return NULL; | |
138 | } | |
139 | ||
140 | /** | |
141 | * vgic_handle_mmio - handle an in-kernel MMIO access | |
142 | * @vcpu: pointer to the vcpu performing the access | |
143 | * @run: pointer to the kvm_run structure | |
144 | * @mmio: pointer to the data describing the access | |
145 | * | |
146 | * returns true if the MMIO access has been performed in kernel space, | |
147 | * and false if it needs to be emulated in user space. | |
148 | */ | |
149 | bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run, | |
150 | struct kvm_exit_mmio *mmio) | |
151 | { | |
152 | return KVM_EXIT_MMIO; | |
153 | } |