xref: /openbmc/qemu/hw/misc/armsse-mhu.c (revision 3d9569b8)
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 "sysemu/sysemu.h"
24 #include "hw/sysbus.h"
25 #include "hw/registerfields.h"
26 #include "hw/misc/armsse-mhu.h"
27 
28 REG32(CPU0INTR_STAT, 0x0)
29 REG32(CPU0INTR_SET, 0x4)
30 REG32(CPU0INTR_CLR, 0x8)
31 REG32(CPU1INTR_STAT, 0x10)
32 REG32(CPU1INTR_SET, 0x14)
33 REG32(CPU1INTR_CLR, 0x18)
34 REG32(PID4, 0xfd0)
35 REG32(PID5, 0xfd4)
36 REG32(PID6, 0xfd8)
37 REG32(PID7, 0xfdc)
38 REG32(PID0, 0xfe0)
39 REG32(PID1, 0xfe4)
40 REG32(PID2, 0xfe8)
41 REG32(PID3, 0xfec)
42 REG32(CID0, 0xff0)
43 REG32(CID1, 0xff4)
44 REG32(CID2, 0xff8)
45 REG32(CID3, 0xffc)
46 
47 /* Valid bits in the interrupt registers. If any are set the IRQ is raised */
48 #define INTR_MASK 0xf
49 
50 /* PID/CID values */
51 static const int armsse_mhu_id[] = {
52     0x04, 0x00, 0x00, 0x00, /* PID4..PID7 */
53     0x56, 0xb8, 0x0b, 0x00, /* PID0..PID3 */
54     0x0d, 0xf0, 0x05, 0xb1, /* CID0..CID3 */
55 };
56 
57 static void armsse_mhu_update(ARMSSEMHU *s)
58 {
59     qemu_set_irq(s->cpu0irq, s->cpu0intr != 0);
60     qemu_set_irq(s->cpu1irq, s->cpu1intr != 0);
61 }
62 
63 static uint64_t armsse_mhu_read(void *opaque, hwaddr offset, unsigned size)
64 {
65     ARMSSEMHU *s = ARMSSE_MHU(opaque);
66     uint64_t r;
67 
68     switch (offset) {
69     case A_CPU0INTR_STAT:
70         r = s->cpu0intr;
71         break;
72 
73     case A_CPU1INTR_STAT:
74         r = s->cpu1intr;
75         break;
76 
77     case A_PID4 ... A_CID3:
78         r = armsse_mhu_id[(offset - A_PID4) / 4];
79         break;
80 
81     case A_CPU0INTR_SET:
82     case A_CPU0INTR_CLR:
83     case A_CPU1INTR_SET:
84     case A_CPU1INTR_CLR:
85         qemu_log_mask(LOG_GUEST_ERROR,
86                       "SSE MHU: read of write-only register at offset 0x%x\n",
87                       (int)offset);
88         r = 0;
89         break;
90 
91     default:
92         qemu_log_mask(LOG_GUEST_ERROR,
93                       "SSE MHU read: bad offset 0x%x\n", (int)offset);
94         r = 0;
95         break;
96     }
97     trace_armsse_mhu_read(offset, r, size);
98     return r;
99 }
100 
101 static void armsse_mhu_write(void *opaque, hwaddr offset,
102                              uint64_t value, unsigned size)
103 {
104     ARMSSEMHU *s = ARMSSE_MHU(opaque);
105 
106     trace_armsse_mhu_write(offset, value, size);
107 
108     switch (offset) {
109     case A_CPU0INTR_SET:
110         s->cpu0intr |= (value & INTR_MASK);
111         break;
112     case A_CPU0INTR_CLR:
113         s->cpu0intr &= ~(value & INTR_MASK);
114         break;
115     case A_CPU1INTR_SET:
116         s->cpu1intr |= (value & INTR_MASK);
117         break;
118     case A_CPU1INTR_CLR:
119         s->cpu1intr &= ~(value & INTR_MASK);
120         break;
121 
122     case A_CPU0INTR_STAT:
123     case A_CPU1INTR_STAT:
124     case A_PID4 ... A_CID3:
125         qemu_log_mask(LOG_GUEST_ERROR,
126                       "SSE MHU: write to read-only register at offset 0x%x\n",
127                       (int)offset);
128         break;
129 
130     default:
131         qemu_log_mask(LOG_GUEST_ERROR,
132                       "SSE MHU write: bad offset 0x%x\n", (int)offset);
133         break;
134     }
135 
136     armsse_mhu_update(s);
137 }
138 
139 static const MemoryRegionOps armsse_mhu_ops = {
140     .read = armsse_mhu_read,
141     .write = armsse_mhu_write,
142     .endianness = DEVICE_LITTLE_ENDIAN,
143     .valid.min_access_size = 4,
144     .valid.max_access_size = 4,
145 };
146 
147 static void armsse_mhu_reset(DeviceState *dev)
148 {
149     ARMSSEMHU *s = ARMSSE_MHU(dev);
150 
151     s->cpu0intr = 0;
152     s->cpu1intr = 0;
153 }
154 
155 static const VMStateDescription armsse_mhu_vmstate = {
156     .name = "armsse-mhu",
157     .version_id = 1,
158     .minimum_version_id = 1,
159     .fields = (VMStateField[]) {
160         VMSTATE_UINT32(cpu0intr, ARMSSEMHU),
161         VMSTATE_UINT32(cpu1intr, ARMSSEMHU),
162         VMSTATE_END_OF_LIST()
163     },
164 };
165 
166 static void armsse_mhu_init(Object *obj)
167 {
168     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
169     ARMSSEMHU *s = ARMSSE_MHU(obj);
170 
171     memory_region_init_io(&s->iomem, obj, &armsse_mhu_ops,
172                           s, "armsse-mhu", 0x1000);
173     sysbus_init_mmio(sbd, &s->iomem);
174     sysbus_init_irq(sbd, &s->cpu0irq);
175     sysbus_init_irq(sbd, &s->cpu1irq);
176 }
177 
178 static void armsse_mhu_class_init(ObjectClass *klass, void *data)
179 {
180     DeviceClass *dc = DEVICE_CLASS(klass);
181 
182     dc->reset = armsse_mhu_reset;
183     dc->vmsd = &armsse_mhu_vmstate;
184 }
185 
186 static const TypeInfo armsse_mhu_info = {
187     .name = TYPE_ARMSSE_MHU,
188     .parent = TYPE_SYS_BUS_DEVICE,
189     .instance_size = sizeof(ARMSSEMHU),
190     .instance_init = armsse_mhu_init,
191     .class_init = armsse_mhu_class_init,
192 };
193 
194 static void armsse_mhu_register_types(void)
195 {
196     type_register_static(&armsse_mhu_info);
197 }
198 
199 type_init(armsse_mhu_register_types);
200