hw/misc/a9scu.c

   1 /*
   2  * Cortex-A9MPCore Snoop Control Unit (SCU) emulation.
   3  *
   4  * Copyright (c) 2009 CodeSourcery.
   5  * Copyright (c) 2011 Linaro Limited.
   6  * Written by Paul Brook, Peter Maydell.
   7  *
   8  * This code is licensed under the GPL.
   9  */
  10
  11 #include "hw/sysbus.h"
  12
  13 /* A9MP private memory region.  */
  14
  15 typedef struct A9SCUState {
  16     SysBusDevice busdev;
  17     MemoryRegion iomem;
  18     uint32_t control;
  19     uint32_t status;
  20     uint32_t num_cpu;
  21 } A9SCUState;
  22
  23 #define TYPE_A9_SCU "a9-scu"
  24 #define A9_SCU(obj) OBJECT_CHECK(A9SCUState, (obj), TYPE_A9_SCU)
  25
  26 static uint64_t a9_scu_read(void *opaque, hwaddr offset,
  27                             unsigned size)
  28 {
  29     A9SCUState *s = (A9SCUState *)opaque;
  30     switch (offset) {
  31     case 0x00: /* Control */
  32         return s->control;
  33     case 0x04: /* Configuration */
  34         return (((1 << s->num_cpu) - 1) << 4) | (s->num_cpu - 1);
  35     case 0x08: /* CPU Power Status */
  36         return s->status;
  37     case 0x09: /* CPU status.  */
  38         return s->status >> 8;
  39     case 0x0a: /* CPU status.  */
  40         return s->status >> 16;
  41     case 0x0b: /* CPU status.  */
  42         return s->status >> 24;
  43     case 0x0c: /* Invalidate All Registers In Secure State */
  44         return 0;
  45     case 0x40: /* Filtering Start Address Register */
  46     case 0x44: /* Filtering End Address Register */
  47         /* RAZ/WI, like an implementation with only one AXI master */
  48         return 0;
  49     case 0x50: /* SCU Access Control Register */
  50     case 0x54: /* SCU Non-secure Access Control Register */
  51         /* unimplemented, fall through */
  52     default:
  53         return 0;
  54     }
  55 }
  56
  57 static void a9_scu_write(void *opaque, hwaddr offset,
  58                          uint64_t value, unsigned size)
  59 {
  60     A9SCUState *s = (A9SCUState *)opaque;
  61     uint32_t mask;
  62     uint32_t shift;
  63     switch (size) {
  64     case 1:
  65         mask = 0xff;
  66         break;
  67     case 2:
  68         mask = 0xffff;
  69         break;
  70     case 4:
  71         mask = 0xffffffff;
  72         break;
  73     default:
  74         fprintf(stderr, "Invalid size %u in write to a9 scu register %x\n",
  75                 size, (unsigned)offset);
  76         return;
  77     }
  78
  79     switch (offset) {
  80     case 0x00: /* Control */
  81         s->control = value & 1;
  82         break;
  83     case 0x4: /* Configuration: RO */
  84         break;
  85     case 0x08: case 0x09: case 0x0A: case 0x0B: /* Power Control */
  86         shift = (offset - 0x8) * 8;
  87         s->status &= ~(mask << shift);
  88         s->status |= ((value & mask) << shift);
  89         break;
  90     case 0x0c: /* Invalidate All Registers In Secure State */
  91         /* no-op as we do not implement caches */
  92         break;
  93     case 0x40: /* Filtering Start Address Register */
  94     case 0x44: /* Filtering End Address Register */
  95         /* RAZ/WI, like an implementation with only one AXI master */
  96         break;
  97     case 0x50: /* SCU Access Control Register */
  98     case 0x54: /* SCU Non-secure Access Control Register */
  99         /* unimplemented, fall through */
 100     default:
 101         break;
 102     }
 103 }
 104
 105 static const MemoryRegionOps a9_scu_ops = {
 106     .read = a9_scu_read,
 107     .write = a9_scu_write,
 108     .endianness = DEVICE_NATIVE_ENDIAN,
 109 };
 110
 111 static void a9_scu_reset(DeviceState *dev)
 112 {
 113     A9SCUState *s = A9_SCU(dev);
 114     s->control = 0;
 115 }
 116
 117 static void a9_scu_realize(DeviceState *dev, Error ** errp)
 118 {
 119     A9SCUState *s = A9_SCU(dev);
 120     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 121
 122     memory_region_init_io(&s->iomem, &a9_scu_ops, s, "a9-scu", 0x100);
 123     sysbus_init_mmio(sbd, &s->iomem);
 124 }
 125
 126 static const VMStateDescription vmstate_a9_scu = {
 127     .name = "a9-scu",
 128     .version_id = 1,
 129     .minimum_version_id = 1,
 130     .fields = (VMStateField[]) {
 131         VMSTATE_UINT32(control, A9SCUState),
 132         VMSTATE_UINT32(status, A9SCUState),
 133         VMSTATE_END_OF_LIST()
 134     }
 135 };
 136
 137 static Property a9_scu_properties[] = {
 138     DEFINE_PROP_UINT32("num-cpu", A9SCUState, num_cpu, 1),
 139     DEFINE_PROP_END_OF_LIST(),
 140 };
 141
 142 static void a9_scu_class_init(ObjectClass *klass, void *data)
 143 {
 144     DeviceClass *dc = DEVICE_CLASS(klass);
 145
 146     dc->realize = a9_scu_realize;
 147     dc->props = a9_scu_properties;
 148     dc->vmsd = &vmstate_a9_scu;
 149     dc->reset = a9_scu_reset;
 150 }
 151
 152 static const TypeInfo a9_scu_info = {
 153     .name          = TYPE_A9_SCU,
 154     .parent        = TYPE_SYS_BUS_DEVICE,
 155     .instance_size = sizeof(A9SCUState),
 156     .class_init    = a9_scu_class_init,
 157 };
 158
 159 static void a9mp_register_types(void)
 160 {
 161     type_register_static(&a9_scu_info);
 162 }
 163
 164 type_init(a9mp_register_types)