xref: /openbmc/qemu/hw/misc/a9scu.c (revision d6032e06)
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 "hw/misc/a9scu.h"
12 
13 static uint64_t a9_scu_read(void *opaque, hwaddr offset,
14                             unsigned size)
15 {
16     A9SCUState *s = (A9SCUState *)opaque;
17     switch (offset) {
18     case 0x00: /* Control */
19         return s->control;
20     case 0x04: /* Configuration */
21         return (((1 << s->num_cpu) - 1) << 4) | (s->num_cpu - 1);
22     case 0x08: /* CPU Power Status */
23         return s->status;
24     case 0x09: /* CPU status.  */
25         return s->status >> 8;
26     case 0x0a: /* CPU status.  */
27         return s->status >> 16;
28     case 0x0b: /* CPU status.  */
29         return s->status >> 24;
30     case 0x0c: /* Invalidate All Registers In Secure State */
31         return 0;
32     case 0x40: /* Filtering Start Address Register */
33     case 0x44: /* Filtering End Address Register */
34         /* RAZ/WI, like an implementation with only one AXI master */
35         return 0;
36     case 0x50: /* SCU Access Control Register */
37     case 0x54: /* SCU Non-secure Access Control Register */
38         /* unimplemented, fall through */
39     default:
40         return 0;
41     }
42 }
43 
44 static void a9_scu_write(void *opaque, hwaddr offset,
45                          uint64_t value, unsigned size)
46 {
47     A9SCUState *s = (A9SCUState *)opaque;
48     uint32_t mask;
49     uint32_t shift;
50     switch (size) {
51     case 1:
52         mask = 0xff;
53         break;
54     case 2:
55         mask = 0xffff;
56         break;
57     case 4:
58         mask = 0xffffffff;
59         break;
60     default:
61         fprintf(stderr, "Invalid size %u in write to a9 scu register %x\n",
62                 size, (unsigned)offset);
63         return;
64     }
65 
66     switch (offset) {
67     case 0x00: /* Control */
68         s->control = value & 1;
69         break;
70     case 0x4: /* Configuration: RO */
71         break;
72     case 0x08: case 0x09: case 0x0A: case 0x0B: /* Power Control */
73         shift = (offset - 0x8) * 8;
74         s->status &= ~(mask << shift);
75         s->status |= ((value & mask) << shift);
76         break;
77     case 0x0c: /* Invalidate All Registers In Secure State */
78         /* no-op as we do not implement caches */
79         break;
80     case 0x40: /* Filtering Start Address Register */
81     case 0x44: /* Filtering End Address Register */
82         /* RAZ/WI, like an implementation with only one AXI master */
83         break;
84     case 0x50: /* SCU Access Control Register */
85     case 0x54: /* SCU Non-secure Access Control Register */
86         /* unimplemented, fall through */
87     default:
88         break;
89     }
90 }
91 
92 static const MemoryRegionOps a9_scu_ops = {
93     .read = a9_scu_read,
94     .write = a9_scu_write,
95     .endianness = DEVICE_NATIVE_ENDIAN,
96 };
97 
98 static void a9_scu_reset(DeviceState *dev)
99 {
100     A9SCUState *s = A9_SCU(dev);
101     s->control = 0;
102 }
103 
104 static void a9_scu_init(Object *obj)
105 {
106     A9SCUState *s = A9_SCU(obj);
107     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
108 
109     memory_region_init_io(&s->iomem, obj, &a9_scu_ops, s,
110                           "a9-scu", 0x100);
111     sysbus_init_mmio(sbd, &s->iomem);
112 }
113 
114 static const VMStateDescription vmstate_a9_scu = {
115     .name = "a9-scu",
116     .version_id = 1,
117     .minimum_version_id = 1,
118     .fields = (VMStateField[]) {
119         VMSTATE_UINT32(control, A9SCUState),
120         VMSTATE_UINT32(status, A9SCUState),
121         VMSTATE_END_OF_LIST()
122     }
123 };
124 
125 static Property a9_scu_properties[] = {
126     DEFINE_PROP_UINT32("num-cpu", A9SCUState, num_cpu, 1),
127     DEFINE_PROP_END_OF_LIST(),
128 };
129 
130 static void a9_scu_class_init(ObjectClass *klass, void *data)
131 {
132     DeviceClass *dc = DEVICE_CLASS(klass);
133 
134     dc->props = a9_scu_properties;
135     dc->vmsd = &vmstate_a9_scu;
136     dc->reset = a9_scu_reset;
137 }
138 
139 static const TypeInfo a9_scu_info = {
140     .name          = TYPE_A9_SCU,
141     .parent        = TYPE_SYS_BUS_DEVICE,
142     .instance_size = sizeof(A9SCUState),
143     .instance_init = a9_scu_init,
144     .class_init    = a9_scu_class_init,
145 };
146 
147 static void a9mp_register_types(void)
148 {
149     type_register_static(&a9_scu_info);
150 }
151 
152 type_init(a9mp_register_types)
153