hw/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 "hw.h"
  31 #include "sysemu/sysemu.h"
  32 #include "sysbus.h"
  33 #include "sysemu/kvm.h"
  34
  35 #define MAX_CPUS 32
  36
  37 typedef struct spin_info {
  38     uint64_t addr;
  39     uint64_t r3;
  40     uint32_t resv;
  41     uint32_t pir;
  42     uint64_t reserved;
  43 } QEMU_PACKED SpinInfo;
  44
  45 typedef struct spin_state {
  46     SysBusDevice busdev;
  47     MemoryRegion iomem;
  48     SpinInfo spin[MAX_CPUS];
  49 } SpinState;
  50
  51 typedef struct spin_kick {
  52     PowerPCCPU *cpu;
  53     SpinInfo *spin;
  54 } SpinKick;
  55
  56 static void spin_reset(void *opaque)
  57 {
  58     SpinState *s = opaque;
  59     int i;
  60
  61     for (i = 0; i < MAX_CPUS; i++) {
  62         SpinInfo *info = &s->spin[i];
  63
  64         info->pir = i;
  65         info->r3 = i;
  66         info->addr = 1;
  67     }
  68 }
  69
  70 /* Create -kernel TLB entries for BookE, linearly spanning 256MB.  */
  71 static inline hwaddr booke206_page_size_to_tlb(uint64_t size)
  72 {
  73     return (ffs(size >> 10) - 1) >> 1;
  74 }
  75
  76 static void mmubooke_create_initial_mapping(CPUPPCState *env,
  77                                      target_ulong va,
  78                                      hwaddr pa,
  79                                      hwaddr len)
  80 {
  81     ppcmas_tlb_t *tlb = booke206_get_tlbm(env, 1, 0, 1);
  82     hwaddr size;
  83
  84     size = (booke206_page_size_to_tlb(len) << MAS1_TSIZE_SHIFT);
  85     tlb->mas1 = MAS1_VALID | size;
  86     tlb->mas2 = (va & TARGET_PAGE_MASK) | MAS2_M;
  87     tlb->mas7_3 = pa & TARGET_PAGE_MASK;
  88     tlb->mas7_3 |= MAS3_UR | MAS3_UW | MAS3_UX | MAS3_SR | MAS3_SW | MAS3_SX;
  89     env->tlb_dirty = true;
  90 }
  91
  92 static void spin_kick(void *data)
  93 {
  94     SpinKick *kick = data;
  95     CPUState *cpu = CPU(kick->cpu);
  96     CPUPPCState *env = &kick->cpu->env;
  97     SpinInfo *curspin = kick->spin;
  98     hwaddr map_size = 64 * 1024 * 1024;
  99     hwaddr map_start;
 100
 101     cpu_synchronize_state(env);
 102     stl_p(&curspin->pir, env->spr[SPR_PIR]);
 103     env->nip = ldq_p(&curspin->addr) & (map_size - 1);
 104     env->gpr[3] = ldq_p(&curspin->r3);
 105     env->gpr[4] = 0;
 106     env->gpr[5] = 0;
 107     env->gpr[6] = 0;
 108     env->gpr[7] = map_size;
 109     env->gpr[8] = 0;
 110     env->gpr[9] = 0;
 111
 112     map_start = ldq_p(&curspin->addr) & ~(map_size - 1);
 113     mmubooke_create_initial_mapping(env, 0, map_start, map_size);
 114
 115     env->halted = 0;
 116     env->exception_index = -1;
 117     cpu->stopped = false;
 118     qemu_cpu_kick(cpu);
 119 }
 120
 121 static void spin_write(void *opaque, hwaddr addr, uint64_t value,
 122                        unsigned len)
 123 {
 124     SpinState *s = opaque;
 125     int env_idx = addr / sizeof(SpinInfo);
 126     CPUPPCState *env;
 127     CPUState *cpu = NULL;
 128     SpinInfo *curspin = &s->spin[env_idx];
 129     uint8_t *curspin_p = (uint8_t*)curspin;
 130
 131     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 132         cpu = CPU(ppc_env_get_cpu(env));
 133         if (cpu->cpu_index == env_idx) {
 134             break;
 135         }
 136     }
 137
 138     if (cpu == NULL) {
 139         /* Unknown CPU */
 140         return;
 141     }
 142
 143     if (cpu->cpu_index == 0) {
 144         /* primary CPU doesn't spin */
 145         return;
 146     }
 147
 148     curspin_p = &curspin_p[addr % sizeof(SpinInfo)];
 149     switch (len) {
 150     case 1:
 151         stb_p(curspin_p, value);
 152         break;
 153     case 2:
 154         stw_p(curspin_p, value);
 155         break;
 156     case 4:
 157         stl_p(curspin_p, value);
 158         break;
 159     }
 160
 161     if (!(ldq_p(&curspin->addr) & 1)) {
 162         /* run CPU */
 163         SpinKick kick = {
 164             .cpu = ppc_env_get_cpu(env),
 165             .spin = curspin,
 166         };
 167
 168         run_on_cpu(CPU(kick.cpu), spin_kick, &kick);
 169     }
 170 }
 171
 172 static uint64_t spin_read(void *opaque, hwaddr addr, unsigned len)
 173 {
 174     SpinState *s = opaque;
 175     uint8_t *spin_p = &((uint8_t*)s->spin)[addr];
 176
 177     switch (len) {
 178     case 1:
 179         return ldub_p(spin_p);
 180     case 2:
 181         return lduw_p(spin_p);
 182     case 4:
 183         return ldl_p(spin_p);
 184     default:
 185         hw_error("ppce500: unexpected %s with len = %u", __func__, len);
 186     }
 187 }
 188
 189 static const MemoryRegionOps spin_rw_ops = {
 190     .read = spin_read,
 191     .write = spin_write,
 192     .endianness = DEVICE_BIG_ENDIAN,
 193 };
 194
 195 static int ppce500_spin_initfn(SysBusDevice *dev)
 196 {
 197     SpinState *s;
 198
 199     s = FROM_SYSBUS(SpinState, SYS_BUS_DEVICE(dev));
 200
 201     memory_region_init_io(&s->iomem, &spin_rw_ops, s, "e500 spin pv device",
 202                           sizeof(SpinInfo) * MAX_CPUS);
 203     sysbus_init_mmio(dev, &s->iomem);
 204
 205     qemu_register_reset(spin_reset, s);
 206
 207     return 0;
 208 }
 209
 210 static void ppce500_spin_class_init(ObjectClass *klass, void *data)
 211 {
 212     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 213
 214     k->init = ppce500_spin_initfn;
 215 }
 216
 217 static const TypeInfo ppce500_spin_info = {
 218     .name          = "e500-spin",
 219     .parent        = TYPE_SYS_BUS_DEVICE,
 220     .instance_size = sizeof(SpinState),
 221     .class_init    = ppce500_spin_class_init,
 222 };
 223
 224 static void ppce500_spin_register_types(void)
 225 {
 226     type_register_static(&ppce500_spin_info);
 227 }
 228
 229 type_init(ppce500_spin_register_types)