hw/ppc/ppce500_spin.c

   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/module.h"
  32 #include "qemu/units.h"
  33 #include "hw/hw.h"
  34 #include "hw/sysbus.h"
  35 #include "sysemu/hw_accel.h"
  36 #include "e500.h"
  37 #include "qom/object.h"
  38
  39 #define MAX_CPUS 32
  40
  41 typedef struct spin_info {
  42     uint64_t addr;
  43     uint64_t r3;
  44     uint32_t resv;
  45     uint32_t pir;
  46     uint64_t reserved;
  47 } QEMU_PACKED SpinInfo;
  48
  49 #define TYPE_E500_SPIN "e500-spin"
  50 OBJECT_DECLARE_SIMPLE_TYPE(SpinState, E500_SPIN)
  51
  52 struct SpinState {
  53     SysBusDevice parent_obj;
  54
  55     MemoryRegion iomem;
  56     SpinInfo spin[MAX_CPUS];
  57 };
  58
  59 static void spin_reset(DeviceState *dev)
  60 {
  61     SpinState *s = E500_SPIN(dev);
  62     int i;
  63
  64     for (i = 0; i < MAX_CPUS; i++) {
  65         SpinInfo *info = &s->spin[i];
  66
  67         stl_p(&info->pir, i);
  68         stq_p(&info->r3, i);
  69         stq_p(&info->addr, 1);
  70     }
  71 }
  72
  73 static void mmubooke_create_initial_mapping(CPUPPCState *env,
  74                                      target_ulong va,
  75                                      hwaddr pa,
  76                                      hwaddr len)
  77 {
  78     ppcmas_tlb_t *tlb = booke206_get_tlbm(env, 1, 0, 1);
  79     hwaddr size;
  80
  81     size = (booke206_page_size_to_tlb(len) << MAS1_TSIZE_SHIFT);
  82     tlb->mas1 = MAS1_VALID | size;
  83     tlb->mas2 = (va & TARGET_PAGE_MASK) | MAS2_M;
  84     tlb->mas7_3 = pa & TARGET_PAGE_MASK;
  85     tlb->mas7_3 |= MAS3_UR | MAS3_UW | MAS3_UX | MAS3_SR | MAS3_SW | MAS3_SX;
  86     env->tlb_dirty = true;
  87 }
  88
  89 static void spin_kick(CPUState *cs, run_on_cpu_data data)
  90 {
  91     PowerPCCPU *cpu = POWERPC_CPU(cs);
  92     CPUPPCState *env = &cpu->env;
  93     SpinInfo *curspin = data.host_ptr;
  94     hwaddr map_size = 64 * MiB;
  95     hwaddr map_start;
  96
  97     cpu_synchronize_state(cs);
  98     stl_p(&curspin->pir, env->spr[SPR_BOOKE_PIR]);
  99     env->nip = ldq_p(&curspin->addr) & (map_size - 1);
 100     env->gpr[3] = ldq_p(&curspin->r3);
 101     env->gpr[4] = 0;
 102     env->gpr[5] = 0;
 103     env->gpr[6] = 0;
 104     env->gpr[7] = map_size;
 105     env->gpr[8] = 0;
 106     env->gpr[9] = 0;
 107
 108     map_start = ldq_p(&curspin->addr) & ~(map_size - 1);
 109     mmubooke_create_initial_mapping(env, 0, map_start, map_size);
 110
 111     cs->halted = 0;
 112     cs->exception_index = -1;
 113     cs->stopped = false;
 114     qemu_cpu_kick(cs);
 115 }
 116
 117 static void spin_write(void *opaque, hwaddr addr, uint64_t value,
 118                        unsigned len)
 119 {
 120     SpinState *s = opaque;
 121     int env_idx = addr / sizeof(SpinInfo);
 122     CPUState *cpu;
 123     SpinInfo *curspin = &s->spin[env_idx];
 124     uint8_t *curspin_p = (uint8_t*)curspin;
 125
 126     cpu = qemu_get_cpu(env_idx);
 127     if (cpu == NULL) {
 128         /* Unknown CPU */
 129         return;
 130     }
 131
 132     if (cpu->cpu_index == 0) {
 133         /* primary CPU doesn't spin */
 134         return;
 135     }
 136
 137     curspin_p = &curspin_p[addr % sizeof(SpinInfo)];
 138     switch (len) {
 139     case 1:
 140         stb_p(curspin_p, value);
 141         break;
 142     case 2:
 143         stw_p(curspin_p, value);
 144         break;
 145     case 4:
 146         stl_p(curspin_p, value);
 147         break;
 148     }
 149
 150     if (!(ldq_p(&curspin->addr) & 1)) {
 151         /* run CPU */
 152         run_on_cpu(cpu, spin_kick, RUN_ON_CPU_HOST_PTR(curspin));
 153     }
 154 }
 155
 156 static uint64_t spin_read(void *opaque, hwaddr addr, unsigned len)
 157 {
 158     SpinState *s = opaque;
 159     uint8_t *spin_p = &((uint8_t*)s->spin)[addr];
 160
 161     switch (len) {
 162     case 1:
 163         return ldub_p(spin_p);
 164     case 2:
 165         return lduw_p(spin_p);
 166     case 4:
 167         return ldl_p(spin_p);
 168     default:
 169         hw_error("ppce500: unexpected %s with len = %u", __func__, len);
 170     }
 171 }
 172
 173 static const MemoryRegionOps spin_rw_ops = {
 174     .read = spin_read,
 175     .write = spin_write,
 176     .endianness = DEVICE_BIG_ENDIAN,
 177 };
 178
 179 static void ppce500_spin_initfn(Object *obj)
 180 {
 181     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
 182     SpinState *s = E500_SPIN(dev);
 183
 184     memory_region_init_io(&s->iomem, obj, &spin_rw_ops, s,
 185                           "e500 spin pv device", sizeof(SpinInfo) * MAX_CPUS);
 186     sysbus_init_mmio(dev, &s->iomem);
 187 }
 188
 189 static void ppce500_spin_class_init(ObjectClass *klass, void *data)
 190 {
 191     DeviceClass *dc = DEVICE_CLASS(klass);
 192
 193     dc->reset = spin_reset;
 194 }
 195
 196 static const TypeInfo ppce500_spin_info = {
 197     .name          = TYPE_E500_SPIN,
 198     .parent        = TYPE_SYS_BUS_DEVICE,
 199     .instance_size = sizeof(SpinState),
 200     .instance_init = ppce500_spin_initfn,
 201     .class_init    = ppce500_spin_class_init,
 202 };
 203
 204 static void ppce500_spin_register_types(void)
 205 {
 206     type_register_static(&ppce500_spin_info);
 207 }
 208
 209 type_init(ppce500_spin_register_types)