1/*
2 * ARM SSE-200 Message Handling Unit (MHU)
3 *
4 * Copyright (c) 2019 Linaro Limited
5 * Written by Peter Maydell
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 or
9 * (at your option) any later version.
10 */
11
12/*
13 * This is a model of the Message Handling Unit (MHU) which is part of the
14 * Arm SSE-200 and documented in
15 * http://infocenter.arm.com/help/topic/com.arm.doc.101104_0100_00_en/corelink_sse200_subsystem_for_embedded_technical_reference_manual_101104_0100_00_en.pdf
16 */
17
18#include "qemu/osdep.h"
19#include "qemu/log.h"
20#include "qemu/module.h"
21#include "trace.h"
22#include "qapi/error.h"
23#include "hw/sysbus.h"
24#include "migration/vmstate.h"
25#include "hw/registerfields.h"
26#include "hw/irq.h"
27#include "hw/misc/armsse-mhu.h"
28
29REG32(CPU0INTR_STAT, 0x0)
30REG32(CPU0INTR_SET, 0x4)
31REG32(CPU0INTR_CLR, 0x8)
32REG32(CPU1INTR_STAT, 0x10)
33REG32(CPU1INTR_SET, 0x14)
34REG32(CPU1INTR_CLR, 0x18)
35REG32(PID4, 0xfd0)
36REG32(PID5, 0xfd4)
37REG32(PID6, 0xfd8)
38REG32(PID7, 0xfdc)
39REG32(PID0, 0xfe0)
40REG32(PID1, 0xfe4)
41REG32(PID2, 0xfe8)
42REG32(PID3, 0xfec)
43REG32(CID0, 0xff0)
44REG32(CID1, 0xff4)
45REG32(CID2, 0xff8)
46REG32(CID3, 0xffc)
47
48/* Valid bits in the interrupt registers. If any are set the IRQ is raised */
49#define INTR_MASK 0xf
50
51/* PID/CID values */
52static const int armsse_mhu_id[] = {
53 0x04, 0x00, 0x00, 0x00, /* PID4..PID7 */
54 0x56, 0xb8, 0x0b, 0x00, /* PID0..PID3 */
55 0x0d, 0xf0, 0x05, 0xb1, /* CID0..CID3 */
56};
57
58static void armsse_mhu_update(ARMSSEMHU *s)
59{
60 qemu_set_irq(s->cpu0irq, s->cpu0intr != 0);
61 qemu_set_irq(s->cpu1irq, s->cpu1intr != 0);
62}
63
64static uint64_t armsse_mhu_read(void *opaque, hwaddr offset, unsigned size)
65{
66 ARMSSEMHU *s = ARMSSE_MHU(opaque);
67 uint64_t r;
68
69 switch (offset) {
70 case A_CPU0INTR_STAT:
71 r = s->cpu0intr;
72 break;
73
74 case A_CPU1INTR_STAT:
75 r = s->cpu1intr;
76 break;
77
78 case A_PID4 ... A_CID3:
79 r = armsse_mhu_id[(offset - A_PID4) / 4];
80 break;
81
82 case A_CPU0INTR_SET:
83 case A_CPU0INTR_CLR:
84 case A_CPU1INTR_SET:
85 case A_CPU1INTR_CLR:
86 qemu_log_mask(LOG_GUEST_ERROR,
87 "SSE MHU: read of write-only register at offset 0x%x\n",
88 (int)offset);
89 r = 0;
90 break;
91
92 default:
93 qemu_log_mask(LOG_GUEST_ERROR,
94 "SSE MHU read: bad offset 0x%x\n", (int)offset);
95 r = 0;
96 break;
97 }
98 trace_armsse_mhu_read(offset, r, size);
99 return r;
100}
101
102static void armsse_mhu_write(void *opaque, hwaddr offset,
103 uint64_t value, unsigned size)
104{
105 ARMSSEMHU *s = ARMSSE_MHU(opaque);
106
107 trace_armsse_mhu_write(offset, value, size);
108
109 switch (offset) {
110 case A_CPU0INTR_SET:
111 s->cpu0intr |= (value & INTR_MASK);
112 break;
113 case A_CPU0INTR_CLR:
114 s->cpu0intr &= ~(value & INTR_MASK);
115 break;
116 case A_CPU1INTR_SET:
117 s->cpu1intr |= (value & INTR_MASK);
118 break;
119 case A_CPU1INTR_CLR:
120 s->cpu1intr &= ~(value & INTR_MASK);
121 break;
122
123 case A_CPU0INTR_STAT:
124 case A_CPU1INTR_STAT:
125 case A_PID4 ... A_CID3:
126 qemu_log_mask(LOG_GUEST_ERROR,
127 "SSE MHU: write to read-only register at offset 0x%x\n",
128 (int)offset);
129 break;
130
131 default:
132 qemu_log_mask(LOG_GUEST_ERROR,
133 "SSE MHU write: bad offset 0x%x\n", (int)offset);
134 break;
135 }
136
137 armsse_mhu_update(s);
138}
139
140static const MemoryRegionOps armsse_mhu_ops = {
141 .read = armsse_mhu_read,
142 .write = armsse_mhu_write,
143 .endianness = DEVICE_LITTLE_ENDIAN,
144 .valid.min_access_size = 4,
145 .valid.max_access_size = 4,
146};
147
148static void armsse_mhu_reset(DeviceState *dev)
149{
150 ARMSSEMHU *s = ARMSSE_MHU(dev);
151
152 s->cpu0intr = 0;
153 s->cpu1intr = 0;
154}
155
156static const VMStateDescription armsse_mhu_vmstate = {
157 .name = "armsse-mhu",
158 .version_id = 1,
159 .minimum_version_id = 1,
160 .fields = (VMStateField[]) {
161 VMSTATE_UINT32(cpu0intr, ARMSSEMHU),
162 VMSTATE_UINT32(cpu1intr, ARMSSEMHU),
163 VMSTATE_END_OF_LIST()
164 },
165};
166
167static void armsse_mhu_init(Object *obj)
168{
169 SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
170 ARMSSEMHU *s = ARMSSE_MHU(obj);
171
172 memory_region_init_io(&s->iomem, obj, &armsse_mhu_ops,
173 s, "armsse-mhu", 0x1000);
174 sysbus_init_mmio(sbd, &s->iomem);
175 sysbus_init_irq(sbd, &s->cpu0irq);
176 sysbus_init_irq(sbd, &s->cpu1irq);
177}
178
179static void armsse_mhu_class_init(ObjectClass *klass, void *data)
180{
181 DeviceClass *dc = DEVICE_CLASS(klass);
182
183 dc->reset = armsse_mhu_reset;
184 dc->vmsd = &armsse_mhu_vmstate;
185}
186
187static const TypeInfo armsse_mhu_info = {
188 .name = TYPE_ARMSSE_MHU,
189 .parent = TYPE_SYS_BUS_DEVICE,
190 .instance_size = sizeof(ARMSSEMHU),
191 .instance_init = armsse_mhu_init,
192 .class_init = armsse_mhu_class_init,
193};
194
195static void armsse_mhu_register_types(void)
196{
197 type_register_static(&armsse_mhu_info);
198}
199
200type_init(armsse_mhu_register_types);
201