qemu/hw/ppc/ppce500_spin.c
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   1/*
   2 * QEMU PowerPC e500v2 ePAPR spinning code
   3 *
   4 * Copyright (C) 2011 Freescale Semiconductor, Inc. All rights reserved.
   5 *
   6 * Author: Alexander Graf, <agraf@suse.de>
   7 *
   8 * This library is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU Lesser General Public
  10 * License as published by the Free Software Foundation; either
  11 * version 2 of the License, or (at your option) any later version.
  12 *
  13 * This library is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 * Lesser General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU Lesser General Public
  19 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  20 *
  21 * This code is not really a device, but models an interface that usually
  22 * firmware takes care of. It's used when QEMU plays the role of firmware.
  23 *
  24 * Specification:
  25 *
  26 * https://www.power.org/resources/downloads/Power_ePAPR_APPROVED_v1.1.pdf
  27 *
  28 */
  29
  30#include "qemu/osdep.h"
  31#include "qemu/units.h"
  32#include "hw/hw.h"
  33#include "hw/sysbus.h"
  34#include "sysemu/hw_accel.h"
  35#include "sysemu/sysemu.h"
  36#include "e500.h"
  37
  38#define MAX_CPUS 32
  39
  40typedef struct spin_info {
  41    uint64_t addr;
  42    uint64_t r3;
  43    uint32_t resv;
  44    uint32_t pir;
  45    uint64_t reserved;
  46} QEMU_PACKED SpinInfo;
  47
  48#define TYPE_E500_SPIN "e500-spin"
  49#define E500_SPIN(obj) OBJECT_CHECK(SpinState, (obj), TYPE_E500_SPIN)
  50
  51typedef struct SpinState {
  52    SysBusDevice parent_obj;
  53
  54    MemoryRegion iomem;
  55    SpinInfo spin[MAX_CPUS];
  56} SpinState;
  57
  58static void spin_reset(DeviceState *dev)
  59{
  60    SpinState *s = E500_SPIN(dev);
  61    int i;
  62
  63    for (i = 0; i < MAX_CPUS; i++) {
  64        SpinInfo *info = &s->spin[i];
  65
  66        stl_p(&info->pir, i);
  67        stq_p(&info->r3, i);
  68        stq_p(&info->addr, 1);
  69    }
  70}
  71
  72static void mmubooke_create_initial_mapping(CPUPPCState *env,
  73                                     target_ulong va,
  74                                     hwaddr pa,
  75                                     hwaddr len)
  76{
  77    ppcmas_tlb_t *tlb = booke206_get_tlbm(env, 1, 0, 1);
  78    hwaddr size;
  79
  80    size = (booke206_page_size_to_tlb(len) << MAS1_TSIZE_SHIFT);
  81    tlb->mas1 = MAS1_VALID | size;
  82    tlb->mas2 = (va & TARGET_PAGE_MASK) | MAS2_M;
  83    tlb->mas7_3 = pa & TARGET_PAGE_MASK;
  84    tlb->mas7_3 |= MAS3_UR | MAS3_UW | MAS3_UX | MAS3_SR | MAS3_SW | MAS3_SX;
  85    env->tlb_dirty = true;
  86}
  87
  88static void spin_kick(CPUState *cs, run_on_cpu_data data)
  89{
  90    PowerPCCPU *cpu = POWERPC_CPU(cs);
  91    CPUPPCState *env = &cpu->env;
  92    SpinInfo *curspin = data.host_ptr;
  93    hwaddr map_size = 64 * MiB;
  94    hwaddr map_start;
  95
  96    cpu_synchronize_state(cs);
  97    stl_p(&curspin->pir, env->spr[SPR_BOOKE_PIR]);
  98    env->nip = ldq_p(&curspin->addr) & (map_size - 1);
  99    env->gpr[3] = ldq_p(&curspin->r3);
 100    env->gpr[4] = 0;
 101    env->gpr[5] = 0;
 102    env->gpr[6] = 0;
 103    env->gpr[7] = map_size;
 104    env->gpr[8] = 0;
 105    env->gpr[9] = 0;
 106
 107    map_start = ldq_p(&curspin->addr) & ~(map_size - 1);
 108    mmubooke_create_initial_mapping(env, 0, map_start, map_size);
 109
 110    cs->halted = 0;
 111    cs->exception_index = -1;
 112    cs->stopped = false;
 113    qemu_cpu_kick(cs);
 114}
 115
 116static void spin_write(void *opaque, hwaddr addr, uint64_t value,
 117                       unsigned len)
 118{
 119    SpinState *s = opaque;
 120    int env_idx = addr / sizeof(SpinInfo);
 121    CPUState *cpu;
 122    SpinInfo *curspin = &s->spin[env_idx];
 123    uint8_t *curspin_p = (uint8_t*)curspin;
 124
 125    cpu = qemu_get_cpu(env_idx);
 126    if (cpu == NULL) {
 127        /* Unknown CPU */
 128        return;
 129    }
 130
 131    if (cpu->cpu_index == 0) {
 132        /* primary CPU doesn't spin */
 133        return;
 134    }
 135
 136    curspin_p = &curspin_p[addr % sizeof(SpinInfo)];
 137    switch (len) {
 138    case 1:
 139        stb_p(curspin_p, value);
 140        break;
 141    case 2:
 142        stw_p(curspin_p, value);
 143        break;
 144    case 4:
 145        stl_p(curspin_p, value);
 146        break;
 147    }
 148
 149    if (!(ldq_p(&curspin->addr) & 1)) {
 150        /* run CPU */
 151        run_on_cpu(cpu, spin_kick, RUN_ON_CPU_HOST_PTR(curspin));
 152    }
 153}
 154
 155static uint64_t spin_read(void *opaque, hwaddr addr, unsigned len)
 156{
 157    SpinState *s = opaque;
 158    uint8_t *spin_p = &((uint8_t*)s->spin)[addr];
 159
 160    switch (len) {
 161    case 1:
 162        return ldub_p(spin_p);
 163    case 2:
 164        return lduw_p(spin_p);
 165    case 4:
 166        return ldl_p(spin_p);
 167    default:
 168        hw_error("ppce500: unexpected %s with len = %u", __func__, len);
 169    }
 170}
 171
 172static const MemoryRegionOps spin_rw_ops = {
 173    .read = spin_read,
 174    .write = spin_write,
 175    .endianness = DEVICE_BIG_ENDIAN,
 176};
 177
 178static void ppce500_spin_initfn(Object *obj)
 179{
 180    SysBusDevice *dev = SYS_BUS_DEVICE(obj);
 181    SpinState *s = E500_SPIN(dev);
 182
 183    memory_region_init_io(&s->iomem, obj, &spin_rw_ops, s,
 184                          "e500 spin pv device", sizeof(SpinInfo) * MAX_CPUS);
 185    sysbus_init_mmio(dev, &s->iomem);
 186}
 187
 188static void ppce500_spin_class_init(ObjectClass *klass, void *data)
 189{
 190    DeviceClass *dc = DEVICE_CLASS(klass);
 191
 192    dc->reset = spin_reset;
 193}
 194
 195static const TypeInfo ppce500_spin_info = {
 196    .name          = TYPE_E500_SPIN,
 197    .parent        = TYPE_SYS_BUS_DEVICE,
 198    .instance_size = sizeof(SpinState),
 199    .instance_init = ppce500_spin_initfn,
 200    .class_init    = ppce500_spin_class_init,
 201};
 202
 203static void ppce500_spin_register_types(void)
 204{
 205    type_register_static(&ppce500_spin_info);
 206}
 207
 208type_init(ppce500_spin_register_types)
 209