hw/misc/armsse-mhu.c

   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);