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.h"
  32 #include "sysbus.h"
  33 #include "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 } __attribute__ ((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     CPUPPCState *env;
  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 target_phys_addr_t 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                                      target_phys_addr_t pa,
  79                                      target_phys_addr_t len)
  80 {
  81     ppcmas_tlb_t *tlb = booke206_get_tlbm(env, 1, 0, 1);
  82     target_phys_addr_t 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     CPUPPCState *env = kick->env;
  96     SpinInfo *curspin = kick->spin;
  97     target_phys_addr_t map_size = 64 * 1024 * 1024;
  98     target_phys_addr_t map_start;
  99
 100     cpu_synchronize_state(env);
 101     stl_p(&curspin->pir, env->spr[SPR_PIR]);
 102     env->nip = ldq_p(&curspin->addr) & (map_size - 1);
 103     env->gpr[3] = ldq_p(&curspin->r3);
 104     env->gpr[4] = 0;
 105     env->gpr[5] = 0;
 106     env->gpr[6] = 0;
 107     env->gpr[7] = map_size;
 108     env->gpr[8] = 0;
 109     env->gpr[9] = 0;
 110
 111     map_start = ldq_p(&curspin->addr) & ~(map_size - 1);
 112     mmubooke_create_initial_mapping(env, 0, map_start, map_size);
 113
 114     env->halted = 0;
 115     env->exception_index = -1;
 116     env->stopped = 0;
 117     qemu_cpu_kick(env);
 118 }
 119
 120 static void spin_write(void *opaque, target_phys_addr_t addr, uint64_t value,
 121                        unsigned len)
 122 {
 123     SpinState *s = opaque;
 124     int env_idx = addr / sizeof(SpinInfo);
 125     CPUPPCState *env;
 126     SpinInfo *curspin = &s->spin[env_idx];
 127     uint8_t *curspin_p = (uint8_t*)curspin;
 128
 129     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 130         if (env->cpu_index == env_idx) {
 131             break;
 132         }
 133     }
 134
 135     if (!env) {
 136         /* Unknown CPU */
 137         return;
 138     }
 139
 140     if (!env->cpu_index) {
 141         /* primary CPU doesn't spin */
 142         return;
 143     }
 144
 145     curspin_p = &curspin_p[addr % sizeof(SpinInfo)];
 146     switch (len) {
 147     case 1:
 148         stb_p(curspin_p, value);
 149         break;
 150     case 2:
 151         stw_p(curspin_p, value);
 152         break;
 153     case 4:
 154         stl_p(curspin_p, value);
 155         break;
 156     }
 157
 158     if (!(ldq_p(&curspin->addr) & 1)) {
 159         /* run CPU */
 160         SpinKick kick = {
 161             .env = env,
 162             .spin = curspin,
 163         };
 164
 165         run_on_cpu(env, spin_kick, &kick);
 166     }
 167 }
 168
 169 static uint64_t spin_read(void *opaque, target_phys_addr_t addr, unsigned len)
 170 {
 171     SpinState *s = opaque;
 172     uint8_t *spin_p = &((uint8_t*)s->spin)[addr];
 173
 174     switch (len) {
 175     case 1:
 176         return ldub_p(spin_p);
 177     case 2:
 178         return lduw_p(spin_p);
 179     case 4:
 180         return ldl_p(spin_p);
 181     default:
 182         hw_error("ppce500: unexpected %s with len = %u", __func__, len);
 183     }
 184 }
 185
 186 static const MemoryRegionOps spin_rw_ops = {
 187     .read = spin_read,
 188     .write = spin_write,
 189     .endianness = DEVICE_BIG_ENDIAN,
 190 };
 191
 192 static int ppce500_spin_initfn(SysBusDevice *dev)
 193 {
 194     SpinState *s;
 195
 196     s = FROM_SYSBUS(SpinState, sysbus_from_qdev(dev));
 197
 198     memory_region_init_io(&s->iomem, &spin_rw_ops, s, "e500 spin pv device",
 199                           sizeof(SpinInfo) * MAX_CPUS);
 200     sysbus_init_mmio(dev, &s->iomem);
 201
 202     qemu_register_reset(spin_reset, s);
 203
 204     return 0;
 205 }
 206
 207 static void ppce500_spin_class_init(ObjectClass *klass, void *data)
 208 {
 209     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 210
 211     k->init = ppce500_spin_initfn;
 212 }
 213
 214 static TypeInfo ppce500_spin_info = {
 215     .name          = "e500-spin",
 216     .parent        = TYPE_SYS_BUS_DEVICE,
 217     .instance_size = sizeof(SpinState),
 218     .class_init    = ppce500_spin_class_init,
 219 };
 220
 221 static void ppce500_spin_register_types(void)
 222 {
 223     type_register_static(&ppce500_spin_info);
 224 }
 225
 226 type_init(ppce500_spin_register_types)