xref: /openbmc/qemu/hw/misc/armsse-mhu.c (revision db725815)
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 "migration/vmstate.h"
26 #include "hw/registerfields.h"
27 #include "hw/irq.h"
28 #include "hw/misc/armsse-mhu.h"
29 
30 REG32(CPU0INTR_STAT, 0x0)
31 REG32(CPU0INTR_SET, 0x4)
32 REG32(CPU0INTR_CLR, 0x8)
33 REG32(CPU1INTR_STAT, 0x10)
34 REG32(CPU1INTR_SET, 0x14)
35 REG32(CPU1INTR_CLR, 0x18)
36 REG32(PID4, 0xfd0)
37 REG32(PID5, 0xfd4)
38 REG32(PID6, 0xfd8)
39 REG32(PID7, 0xfdc)
40 REG32(PID0, 0xfe0)
41 REG32(PID1, 0xfe4)
42 REG32(PID2, 0xfe8)
43 REG32(PID3, 0xfec)
44 REG32(CID0, 0xff0)
45 REG32(CID1, 0xff4)
46 REG32(CID2, 0xff8)
47 REG32(CID3, 0xffc)
48 
49 /* Valid bits in the interrupt registers. If any are set the IRQ is raised */
50 #define INTR_MASK 0xf
51 
52 /* PID/CID values */
53 static const int armsse_mhu_id[] = {
54     0x04, 0x00, 0x00, 0x00, /* PID4..PID7 */
55     0x56, 0xb8, 0x0b, 0x00, /* PID0..PID3 */
56     0x0d, 0xf0, 0x05, 0xb1, /* CID0..CID3 */
57 };
58 
59 static void armsse_mhu_update(ARMSSEMHU *s)
60 {
61     qemu_set_irq(s->cpu0irq, s->cpu0intr != 0);
62     qemu_set_irq(s->cpu1irq, s->cpu1intr != 0);
63 }
64 
65 static uint64_t armsse_mhu_read(void *opaque, hwaddr offset, unsigned size)
66 {
67     ARMSSEMHU *s = ARMSSE_MHU(opaque);
68     uint64_t r;
69 
70     switch (offset) {
71     case A_CPU0INTR_STAT:
72         r = s->cpu0intr;
73         break;
74 
75     case A_CPU1INTR_STAT:
76         r = s->cpu1intr;
77         break;
78 
79     case A_PID4 ... A_CID3:
80         r = armsse_mhu_id[(offset - A_PID4) / 4];
81         break;
82 
83     case A_CPU0INTR_SET:
84     case A_CPU0INTR_CLR:
85     case A_CPU1INTR_SET:
86     case A_CPU1INTR_CLR:
87         qemu_log_mask(LOG_GUEST_ERROR,
88                       "SSE MHU: read of write-only register at offset 0x%x\n",
89                       (int)offset);
90         r = 0;
91         break;
92 
93     default:
94         qemu_log_mask(LOG_GUEST_ERROR,
95                       "SSE MHU read: bad offset 0x%x\n", (int)offset);
96         r = 0;
97         break;
98     }
99     trace_armsse_mhu_read(offset, r, size);
100     return r;
101 }
102 
103 static void armsse_mhu_write(void *opaque, hwaddr offset,
104                              uint64_t value, unsigned size)
105 {
106     ARMSSEMHU *s = ARMSSE_MHU(opaque);
107 
108     trace_armsse_mhu_write(offset, value, size);
109 
110     switch (offset) {
111     case A_CPU0INTR_SET:
112         s->cpu0intr |= (value & INTR_MASK);
113         break;
114     case A_CPU0INTR_CLR:
115         s->cpu0intr &= ~(value & INTR_MASK);
116         break;
117     case A_CPU1INTR_SET:
118         s->cpu1intr |= (value & INTR_MASK);
119         break;
120     case A_CPU1INTR_CLR:
121         s->cpu1intr &= ~(value & INTR_MASK);
122         break;
123 
124     case A_CPU0INTR_STAT:
125     case A_CPU1INTR_STAT:
126     case A_PID4 ... A_CID3:
127         qemu_log_mask(LOG_GUEST_ERROR,
128                       "SSE MHU: write to read-only register at offset 0x%x\n",
129                       (int)offset);
130         break;
131 
132     default:
133         qemu_log_mask(LOG_GUEST_ERROR,
134                       "SSE MHU write: bad offset 0x%x\n", (int)offset);
135         break;
136     }
137 
138     armsse_mhu_update(s);
139 }
140 
141 static const MemoryRegionOps armsse_mhu_ops = {
142     .read = armsse_mhu_read,
143     .write = armsse_mhu_write,
144     .endianness = DEVICE_LITTLE_ENDIAN,
145     .valid.min_access_size = 4,
146     .valid.max_access_size = 4,
147 };
148 
149 static void armsse_mhu_reset(DeviceState *dev)
150 {
151     ARMSSEMHU *s = ARMSSE_MHU(dev);
152 
153     s->cpu0intr = 0;
154     s->cpu1intr = 0;
155 }
156 
157 static const VMStateDescription armsse_mhu_vmstate = {
158     .name = "armsse-mhu",
159     .version_id = 1,
160     .minimum_version_id = 1,
161     .fields = (VMStateField[]) {
162         VMSTATE_UINT32(cpu0intr, ARMSSEMHU),
163         VMSTATE_UINT32(cpu1intr, ARMSSEMHU),
164         VMSTATE_END_OF_LIST()
165     },
166 };
167 
168 static void armsse_mhu_init(Object *obj)
169 {
170     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
171     ARMSSEMHU *s = ARMSSE_MHU(obj);
172 
173     memory_region_init_io(&s->iomem, obj, &armsse_mhu_ops,
174                           s, "armsse-mhu", 0x1000);
175     sysbus_init_mmio(sbd, &s->iomem);
176     sysbus_init_irq(sbd, &s->cpu0irq);
177     sysbus_init_irq(sbd, &s->cpu1irq);
178 }
179 
180 static void armsse_mhu_class_init(ObjectClass *klass, void *data)
181 {
182     DeviceClass *dc = DEVICE_CLASS(klass);
183 
184     dc->reset = armsse_mhu_reset;
185     dc->vmsd = &armsse_mhu_vmstate;
186 }
187 
188 static const TypeInfo armsse_mhu_info = {
189     .name = TYPE_ARMSSE_MHU,
190     .parent = TYPE_SYS_BUS_DEVICE,
191     .instance_size = sizeof(ARMSSEMHU),
192     .instance_init = armsse_mhu_init,
193     .class_init = armsse_mhu_class_init,
194 };
195 
196 static void armsse_mhu_register_types(void)
197 {
198     type_register_static(&armsse_mhu_info);
199 }
200 
201 type_init(armsse_mhu_register_types);
202