xref: /openbmc/qemu/hw/misc/armsse-mhu.c (revision 750541c4)
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 "trace.h"
21 #include "qapi/error.h"
22 #include "sysemu/sysemu.h"
23 #include "hw/sysbus.h"
24 #include "hw/registerfields.h"
25 #include "hw/misc/armsse-mhu.h"
26 
27 REG32(CPU0INTR_STAT, 0x0)
28 REG32(CPU0INTR_SET, 0x4)
29 REG32(CPU0INTR_CLR, 0x8)
30 REG32(CPU1INTR_STAT, 0x10)
31 REG32(CPU1INTR_SET, 0x14)
32 REG32(CPU1INTR_CLR, 0x18)
33 REG32(PID4, 0xfd0)
34 REG32(PID5, 0xfd4)
35 REG32(PID6, 0xfd8)
36 REG32(PID7, 0xfdc)
37 REG32(PID0, 0xfe0)
38 REG32(PID1, 0xfe4)
39 REG32(PID2, 0xfe8)
40 REG32(PID3, 0xfec)
41 REG32(CID0, 0xff0)
42 REG32(CID1, 0xff4)
43 REG32(CID2, 0xff8)
44 REG32(CID3, 0xffc)
45 
46 /* Valid bits in the interrupt registers. If any are set the IRQ is raised */
47 #define INTR_MASK 0xf
48 
49 /* PID/CID values */
50 static const int armsse_mhu_id[] = {
51     0x04, 0x00, 0x00, 0x00, /* PID4..PID7 */
52     0x56, 0xb8, 0x0b, 0x00, /* PID0..PID3 */
53     0x0d, 0xf0, 0x05, 0xb1, /* CID0..CID3 */
54 };
55 
56 static void armsse_mhu_update(ARMSSEMHU *s)
57 {
58     qemu_set_irq(s->cpu0irq, s->cpu0intr != 0);
59     qemu_set_irq(s->cpu1irq, s->cpu1intr != 0);
60 }
61 
62 static uint64_t armsse_mhu_read(void *opaque, hwaddr offset, unsigned size)
63 {
64     ARMSSEMHU *s = ARMSSE_MHU(opaque);
65     uint64_t r;
66 
67     switch (offset) {
68     case A_CPU0INTR_STAT:
69         r = s->cpu0intr;
70         break;
71 
72     case A_CPU1INTR_STAT:
73         r = s->cpu1intr;
74         break;
75 
76     case A_PID4 ... A_CID3:
77         r = armsse_mhu_id[(offset - A_PID4) / 4];
78         break;
79 
80     case A_CPU0INTR_SET:
81     case A_CPU0INTR_CLR:
82     case A_CPU1INTR_SET:
83     case A_CPU1INTR_CLR:
84         qemu_log_mask(LOG_GUEST_ERROR,
85                       "SSE MHU: read of write-only register at offset 0x%x\n",
86                       (int)offset);
87         r = 0;
88         break;
89 
90     default:
91         qemu_log_mask(LOG_GUEST_ERROR,
92                       "SSE MHU read: bad offset 0x%x\n", (int)offset);
93         r = 0;
94         break;
95     }
96     trace_armsse_mhu_read(offset, r, size);
97     return r;
98 }
99 
100 static void armsse_mhu_write(void *opaque, hwaddr offset,
101                              uint64_t value, unsigned size)
102 {
103     ARMSSEMHU *s = ARMSSE_MHU(opaque);
104 
105     trace_armsse_mhu_write(offset, value, size);
106 
107     switch (offset) {
108     case A_CPU0INTR_SET:
109         s->cpu0intr |= (value & INTR_MASK);
110         break;
111     case A_CPU0INTR_CLR:
112         s->cpu0intr &= ~(value & INTR_MASK);
113         break;
114     case A_CPU1INTR_SET:
115         s->cpu1intr |= (value & INTR_MASK);
116         break;
117     case A_CPU1INTR_CLR:
118         s->cpu1intr &= ~(value & INTR_MASK);
119         break;
120 
121     case A_CPU0INTR_STAT:
122     case A_CPU1INTR_STAT:
123     case A_PID4 ... A_CID3:
124         qemu_log_mask(LOG_GUEST_ERROR,
125                       "SSE MHU: write to read-only register at offset 0x%x\n",
126                       (int)offset);
127         break;
128 
129     default:
130         qemu_log_mask(LOG_GUEST_ERROR,
131                       "SSE MHU write: bad offset 0x%x\n", (int)offset);
132         break;
133     }
134 
135     armsse_mhu_update(s);
136 }
137 
138 static const MemoryRegionOps armsse_mhu_ops = {
139     .read = armsse_mhu_read,
140     .write = armsse_mhu_write,
141     .endianness = DEVICE_LITTLE_ENDIAN,
142     .valid.min_access_size = 4,
143     .valid.max_access_size = 4,
144 };
145 
146 static void armsse_mhu_reset(DeviceState *dev)
147 {
148     ARMSSEMHU *s = ARMSSE_MHU(dev);
149 
150     s->cpu0intr = 0;
151     s->cpu1intr = 0;
152 }
153 
154 static const VMStateDescription armsse_mhu_vmstate = {
155     .name = "armsse-mhu",
156     .version_id = 1,
157     .minimum_version_id = 1,
158     .fields = (VMStateField[]) {
159         VMSTATE_UINT32(cpu0intr, ARMSSEMHU),
160         VMSTATE_UINT32(cpu1intr, ARMSSEMHU),
161         VMSTATE_END_OF_LIST()
162     },
163 };
164 
165 static void armsse_mhu_init(Object *obj)
166 {
167     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
168     ARMSSEMHU *s = ARMSSE_MHU(obj);
169 
170     memory_region_init_io(&s->iomem, obj, &armsse_mhu_ops,
171                           s, "armsse-mhu", 0x1000);
172     sysbus_init_mmio(sbd, &s->iomem);
173     sysbus_init_irq(sbd, &s->cpu0irq);
174     sysbus_init_irq(sbd, &s->cpu1irq);
175 }
176 
177 static void armsse_mhu_class_init(ObjectClass *klass, void *data)
178 {
179     DeviceClass *dc = DEVICE_CLASS(klass);
180 
181     dc->reset = armsse_mhu_reset;
182     dc->vmsd = &armsse_mhu_vmstate;
183 }
184 
185 static const TypeInfo armsse_mhu_info = {
186     .name = TYPE_ARMSSE_MHU,
187     .parent = TYPE_SYS_BUS_DEVICE,
188     .instance_size = sizeof(ARMSSEMHU),
189     .instance_init = armsse_mhu_init,
190     .class_init = armsse_mhu_class_init,
191 };
192 
193 static void armsse_mhu_register_types(void)
194 {
195     type_register_static(&armsse_mhu_info);
196 }
197 
198 type_init(armsse_mhu_register_types);
199