xref: /openbmc/qemu/hw/misc/a9scu.c (revision 9121d02c)
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/sysbus.h"
12 
13 /* A9MP private memory region.  */
14 
15 typedef struct A9SCUState {
16     SysBusDevice busdev;
17     MemoryRegion iomem;
18     uint32_t control;
19     uint32_t status;
20     uint32_t num_cpu;
21 } A9SCUState;
22 
23 #define TYPE_A9_SCU "a9-scu"
24 #define A9_SCU(obj) OBJECT_CHECK(A9SCUState, (obj), TYPE_A9_SCU)
25 
26 static uint64_t a9_scu_read(void *opaque, hwaddr offset,
27                             unsigned size)
28 {
29     A9SCUState *s = (A9SCUState *)opaque;
30     switch (offset) {
31     case 0x00: /* Control */
32         return s->control;
33     case 0x04: /* Configuration */
34         return (((1 << s->num_cpu) - 1) << 4) | (s->num_cpu - 1);
35     case 0x08: /* CPU Power Status */
36         return s->status;
37     case 0x09: /* CPU status.  */
38         return s->status >> 8;
39     case 0x0a: /* CPU status.  */
40         return s->status >> 16;
41     case 0x0b: /* CPU status.  */
42         return s->status >> 24;
43     case 0x0c: /* Invalidate All Registers In Secure State */
44         return 0;
45     case 0x40: /* Filtering Start Address Register */
46     case 0x44: /* Filtering End Address Register */
47         /* RAZ/WI, like an implementation with only one AXI master */
48         return 0;
49     case 0x50: /* SCU Access Control Register */
50     case 0x54: /* SCU Non-secure Access Control Register */
51         /* unimplemented, fall through */
52     default:
53         return 0;
54     }
55 }
56 
57 static void a9_scu_write(void *opaque, hwaddr offset,
58                          uint64_t value, unsigned size)
59 {
60     A9SCUState *s = (A9SCUState *)opaque;
61     uint32_t mask;
62     uint32_t shift;
63     switch (size) {
64     case 1:
65         mask = 0xff;
66         break;
67     case 2:
68         mask = 0xffff;
69         break;
70     case 4:
71         mask = 0xffffffff;
72         break;
73     default:
74         fprintf(stderr, "Invalid size %u in write to a9 scu register %x\n",
75                 size, (unsigned)offset);
76         return;
77     }
78 
79     switch (offset) {
80     case 0x00: /* Control */
81         s->control = value & 1;
82         break;
83     case 0x4: /* Configuration: RO */
84         break;
85     case 0x08: case 0x09: case 0x0A: case 0x0B: /* Power Control */
86         shift = (offset - 0x8) * 8;
87         s->status &= ~(mask << shift);
88         s->status |= ((value & mask) << shift);
89         break;
90     case 0x0c: /* Invalidate All Registers In Secure State */
91         /* no-op as we do not implement caches */
92         break;
93     case 0x40: /* Filtering Start Address Register */
94     case 0x44: /* Filtering End Address Register */
95         /* RAZ/WI, like an implementation with only one AXI master */
96         break;
97     case 0x50: /* SCU Access Control Register */
98     case 0x54: /* SCU Non-secure Access Control Register */
99         /* unimplemented, fall through */
100     default:
101         break;
102     }
103 }
104 
105 static const MemoryRegionOps a9_scu_ops = {
106     .read = a9_scu_read,
107     .write = a9_scu_write,
108     .endianness = DEVICE_NATIVE_ENDIAN,
109 };
110 
111 static void a9_scu_reset(DeviceState *dev)
112 {
113     A9SCUState *s = A9_SCU(dev);
114     s->control = 0;
115 }
116 
117 static void a9_scu_realize(DeviceState *dev, Error ** errp)
118 {
119     A9SCUState *s = A9_SCU(dev);
120     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
121 
122     memory_region_init_io(&s->iomem, OBJECT(dev), &a9_scu_ops, s,
123                           "a9-scu", 0x100);
124     sysbus_init_mmio(sbd, &s->iomem);
125 }
126 
127 static const VMStateDescription vmstate_a9_scu = {
128     .name = "a9-scu",
129     .version_id = 1,
130     .minimum_version_id = 1,
131     .fields = (VMStateField[]) {
132         VMSTATE_UINT32(control, A9SCUState),
133         VMSTATE_UINT32(status, A9SCUState),
134         VMSTATE_END_OF_LIST()
135     }
136 };
137 
138 static Property a9_scu_properties[] = {
139     DEFINE_PROP_UINT32("num-cpu", A9SCUState, num_cpu, 1),
140     DEFINE_PROP_END_OF_LIST(),
141 };
142 
143 static void a9_scu_class_init(ObjectClass *klass, void *data)
144 {
145     DeviceClass *dc = DEVICE_CLASS(klass);
146 
147     dc->realize = a9_scu_realize;
148     dc->props = a9_scu_properties;
149     dc->vmsd = &vmstate_a9_scu;
150     dc->reset = a9_scu_reset;
151 }
152 
153 static const TypeInfo a9_scu_info = {
154     .name          = TYPE_A9_SCU,
155     .parent        = TYPE_SYS_BUS_DEVICE,
156     .instance_size = sizeof(A9SCUState),
157     .class_init    = a9_scu_class_init,
158 };
159 
160 static void a9mp_register_types(void)
161 {
162     type_register_static(&a9_scu_info);
163 }
164 
165 type_init(a9mp_register_types)
166