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 "hw/hw.h"
  31 #include "sysemu/sysemu.h"
  32 #include "hw/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     cpu->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     CPUState *cpu;
 127     SpinInfo *curspin = &s->spin[env_idx];
 128     uint8_t *curspin_p = (uint8_t*)curspin;
 129
 130     cpu = qemu_get_cpu(env_idx);
 131     if (cpu == NULL) {
 132         /* Unknown CPU */
 133         return;
 134     }
 135
 136     if (cpu->cpu_index == 0) {
 137         /* primary CPU doesn't spin */
 138         return;
 139     }
 140
 141     curspin_p = &curspin_p[addr % sizeof(SpinInfo)];
 142     switch (len) {
 143     case 1:
 144         stb_p(curspin_p, value);
 145         break;
 146     case 2:
 147         stw_p(curspin_p, value);
 148         break;
 149     case 4:
 150         stl_p(curspin_p, value);
 151         break;
 152     }
 153
 154     if (!(ldq_p(&curspin->addr) & 1)) {
 155         /* run CPU */
 156         SpinKick kick = {
 157             .cpu = POWERPC_CPU(cpu),
 158             .spin = curspin,
 159         };
 160
 161         run_on_cpu(cpu, spin_kick, &kick);
 162     }
 163 }
 164
 165 static uint64_t spin_read(void *opaque, hwaddr addr, unsigned len)
 166 {
 167     SpinState *s = opaque;
 168     uint8_t *spin_p = &((uint8_t*)s->spin)[addr];
 169
 170     switch (len) {
 171     case 1:
 172         return ldub_p(spin_p);
 173     case 2:
 174         return lduw_p(spin_p);
 175     case 4:
 176         return ldl_p(spin_p);
 177     default:
 178         hw_error("ppce500: unexpected %s with len = %u", __func__, len);
 179     }
 180 }
 181
 182 static const MemoryRegionOps spin_rw_ops = {
 183     .read = spin_read,
 184     .write = spin_write,
 185     .endianness = DEVICE_BIG_ENDIAN,
 186 };
 187
 188 static int ppce500_spin_initfn(SysBusDevice *dev)
 189 {
 190     SpinState *s;
 191
 192     s = FROM_SYSBUS(SpinState, SYS_BUS_DEVICE(dev));
 193
 194     memory_region_init_io(&s->iomem, &spin_rw_ops, s, "e500 spin pv device",
 195                           sizeof(SpinInfo) * MAX_CPUS);
 196     sysbus_init_mmio(dev, &s->iomem);
 197
 198     qemu_register_reset(spin_reset, s);
 199
 200     return 0;
 201 }
 202
 203 static void ppce500_spin_class_init(ObjectClass *klass, void *data)
 204 {
 205     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 206
 207     k->init = ppce500_spin_initfn;
 208 }
 209
 210 static const TypeInfo ppce500_spin_info = {
 211     .name          = "e500-spin",
 212     .parent        = TYPE_SYS_BUS_DEVICE,
 213     .instance_size = sizeof(SpinState),
 214     .class_init    = ppce500_spin_class_init,
 215 };
 216
 217 static void ppce500_spin_register_types(void)
 218 {
 219     type_register_static(&ppce500_spin_info);
 220 }
 221
 222 type_init(ppce500_spin_register_types)