xref: /openbmc/qemu/hw/misc/a9scu.c (revision 3d9569b8)
1 /*
2  * Cortex-A9MPCore Snoop Control Unit (SCU) emulation.
3  *
4  * Copyright (c) 2009 CodeSourcery.
5  * Copyright (c) 2011 Linaro Limited.
6  * Written by Paul Brook, Peter Maydell.
7  *
8  * This code is licensed under the GPL.
9  */
10 
11 #include "qemu/osdep.h"
12 #include "hw/misc/a9scu.h"
13 #include "qemu/module.h"
14 
15 static uint64_t a9_scu_read(void *opaque, hwaddr offset,
16                             unsigned size)
17 {
18     A9SCUState *s = (A9SCUState *)opaque;
19     switch (offset) {
20     case 0x00: /* Control */
21         return s->control;
22     case 0x04: /* Configuration */
23         return (((1 << s->num_cpu) - 1) << 4) | (s->num_cpu - 1);
24     case 0x08: /* CPU Power Status */
25         return s->status;
26     case 0x09: /* CPU status.  */
27         return s->status >> 8;
28     case 0x0a: /* CPU status.  */
29         return s->status >> 16;
30     case 0x0b: /* CPU status.  */
31         return s->status >> 24;
32     case 0x0c: /* Invalidate All Registers In Secure State */
33         return 0;
34     case 0x40: /* Filtering Start Address Register */
35     case 0x44: /* Filtering End Address Register */
36         /* RAZ/WI, like an implementation with only one AXI master */
37         return 0;
38     case 0x50: /* SCU Access Control Register */
39     case 0x54: /* SCU Non-secure Access Control Register */
40         /* unimplemented, fall through */
41     default:
42         return 0;
43     }
44 }
45 
46 static void a9_scu_write(void *opaque, hwaddr offset,
47                          uint64_t value, unsigned size)
48 {
49     A9SCUState *s = (A9SCUState *)opaque;
50     uint32_t mask;
51     uint32_t shift;
52     switch (size) {
53     case 1:
54         mask = 0xff;
55         break;
56     case 2:
57         mask = 0xffff;
58         break;
59     case 4:
60         mask = 0xffffffff;
61         break;
62     default:
63         fprintf(stderr, "Invalid size %u in write to a9 scu register %x\n",
64                 size, (unsigned)offset);
65         return;
66     }
67 
68     switch (offset) {
69     case 0x00: /* Control */
70         s->control = value & 1;
71         break;
72     case 0x4: /* Configuration: RO */
73         break;
74     case 0x08: case 0x09: case 0x0A: case 0x0B: /* Power Control */
75         shift = (offset - 0x8) * 8;
76         s->status &= ~(mask << shift);
77         s->status |= ((value & mask) << shift);
78         break;
79     case 0x0c: /* Invalidate All Registers In Secure State */
80         /* no-op as we do not implement caches */
81         break;
82     case 0x40: /* Filtering Start Address Register */
83     case 0x44: /* Filtering End Address Register */
84         /* RAZ/WI, like an implementation with only one AXI master */
85         break;
86     case 0x50: /* SCU Access Control Register */
87     case 0x54: /* SCU Non-secure Access Control Register */
88         /* unimplemented, fall through */
89     default:
90         break;
91     }
92 }
93 
94 static const MemoryRegionOps a9_scu_ops = {
95     .read = a9_scu_read,
96     .write = a9_scu_write,
97     .endianness = DEVICE_NATIVE_ENDIAN,
98 };
99 
100 static void a9_scu_reset(DeviceState *dev)
101 {
102     A9SCUState *s = A9_SCU(dev);
103     s->control = 0;
104 }
105 
106 static void a9_scu_init(Object *obj)
107 {
108     A9SCUState *s = A9_SCU(obj);
109     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
110 
111     memory_region_init_io(&s->iomem, obj, &a9_scu_ops, s,
112                           "a9-scu", 0x100);
113     sysbus_init_mmio(sbd, &s->iomem);
114 }
115 
116 static const VMStateDescription vmstate_a9_scu = {
117     .name = "a9-scu",
118     .version_id = 1,
119     .minimum_version_id = 1,
120     .fields = (VMStateField[]) {
121         VMSTATE_UINT32(control, A9SCUState),
122         VMSTATE_UINT32(status, A9SCUState),
123         VMSTATE_END_OF_LIST()
124     }
125 };
126 
127 static Property a9_scu_properties[] = {
128     DEFINE_PROP_UINT32("num-cpu", A9SCUState, num_cpu, 1),
129     DEFINE_PROP_END_OF_LIST(),
130 };
131 
132 static void a9_scu_class_init(ObjectClass *klass, void *data)
133 {
134     DeviceClass *dc = DEVICE_CLASS(klass);
135 
136     dc->props = a9_scu_properties;
137     dc->vmsd = &vmstate_a9_scu;
138     dc->reset = a9_scu_reset;
139 }
140 
141 static const TypeInfo a9_scu_info = {
142     .name          = TYPE_A9_SCU,
143     .parent        = TYPE_SYS_BUS_DEVICE,
144     .instance_size = sizeof(A9SCUState),
145     .instance_init = a9_scu_init,
146     .class_init    = a9_scu_class_init,
147 };
148 
149 static void a9mp_register_types(void)
150 {
151     type_register_static(&a9_scu_info);
152 }
153 
154 type_init(a9mp_register_types)
155