xref: /openbmc/qemu/hw/misc/armsse-mhu.c (revision f363d039)
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 
29 REG32(CPU0INTR_STAT, 0x0)
30 REG32(CPU0INTR_SET, 0x4)
31 REG32(CPU0INTR_CLR, 0x8)
32 REG32(CPU1INTR_STAT, 0x10)
33 REG32(CPU1INTR_SET, 0x14)
34 REG32(CPU1INTR_CLR, 0x18)
35 REG32(PID4, 0xfd0)
36 REG32(PID5, 0xfd4)
37 REG32(PID6, 0xfd8)
38 REG32(PID7, 0xfdc)
39 REG32(PID0, 0xfe0)
40 REG32(PID1, 0xfe4)
41 REG32(PID2, 0xfe8)
42 REG32(PID3, 0xfec)
43 REG32(CID0, 0xff0)
44 REG32(CID1, 0xff4)
45 REG32(CID2, 0xff8)
46 REG32(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 */
52 static 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 
58 static 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 
64 static 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 
102 static 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 
140 static 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 
148 static void armsse_mhu_reset(DeviceState *dev)
149 {
150     ARMSSEMHU *s = ARMSSE_MHU(dev);
151 
152     s->cpu0intr = 0;
153     s->cpu1intr = 0;
154 }
155 
156 static 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 
167 static 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 
179 static 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 
187 static 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 
195 static void armsse_mhu_register_types(void)
196 {
197     type_register_static(&armsse_mhu_info);
198 }
199 
200 type_init(armsse_mhu_register_types);
201