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 #define TYPE_E500_SPIN "e500-spin"
  46 #define E500_SPIN(obj) OBJECT_CHECK(SpinState, (obj), TYPE_E500_SPIN)
  47
  48 typedef struct SpinState {
  49     SysBusDevice parent_obj;
  50
  51     MemoryRegion iomem;
  52     SpinInfo spin[MAX_CPUS];
  53 } SpinState;
  54
  55 typedef struct spin_kick {
  56     PowerPCCPU *cpu;
  57     SpinInfo *spin;
  58 } SpinKick;
  59
  60 static void spin_reset(void *opaque)
  61 {
  62     SpinState *s = opaque;
  63     int i;
  64
  65     for (i = 0; i < MAX_CPUS; i++) {
  66         SpinInfo *info = &s->spin[i];
  67
  68         info->pir = i;
  69         info->r3 = i;
  70         info->addr = 1;
  71     }
  72 }
  73
  74 /* Create -kernel TLB entries for BookE, linearly spanning 256MB.  */
  75 static inline hwaddr booke206_page_size_to_tlb(uint64_t size)
  76 {
  77     return (ffs(size >> 10) - 1) >> 1;
  78 }
  79
  80 static void mmubooke_create_initial_mapping(CPUPPCState *env,
  81                                      target_ulong va,
  82                                      hwaddr pa,
  83                                      hwaddr len)
  84 {
  85     ppcmas_tlb_t *tlb = booke206_get_tlbm(env, 1, 0, 1);
  86     hwaddr size;
  87
  88     size = (booke206_page_size_to_tlb(len) << MAS1_TSIZE_SHIFT);
  89     tlb->mas1 = MAS1_VALID | size;
  90     tlb->mas2 = (va & TARGET_PAGE_MASK) | MAS2_M;
  91     tlb->mas7_3 = pa & TARGET_PAGE_MASK;
  92     tlb->mas7_3 |= MAS3_UR | MAS3_UW | MAS3_UX | MAS3_SR | MAS3_SW | MAS3_SX;
  93     env->tlb_dirty = true;
  94 }
  95
  96 static void spin_kick(void *data)
  97 {
  98     SpinKick *kick = data;
  99     CPUState *cpu = CPU(kick->cpu);
 100     CPUPPCState *env = &kick->cpu->env;
 101     SpinInfo *curspin = kick->spin;
 102     hwaddr map_size = 64 * 1024 * 1024;
 103     hwaddr map_start;
 104
 105     cpu_synchronize_state(cpu);
 106     stl_p(&curspin->pir, env->spr[SPR_PIR]);
 107     env->nip = ldq_p(&curspin->addr) & (map_size - 1);
 108     env->gpr[3] = ldq_p(&curspin->r3);
 109     env->gpr[4] = 0;
 110     env->gpr[5] = 0;
 111     env->gpr[6] = 0;
 112     env->gpr[7] = map_size;
 113     env->gpr[8] = 0;
 114     env->gpr[9] = 0;
 115
 116     map_start = ldq_p(&curspin->addr) & ~(map_size - 1);
 117     mmubooke_create_initial_mapping(env, 0, map_start, map_size);
 118
 119     cpu->halted = 0;
 120     env->exception_index = -1;
 121     cpu->stopped = false;
 122     qemu_cpu_kick(cpu);
 123 }
 124
 125 static void spin_write(void *opaque, hwaddr addr, uint64_t value,
 126                        unsigned len)
 127 {
 128     SpinState *s = opaque;
 129     int env_idx = addr / sizeof(SpinInfo);
 130     CPUState *cpu;
 131     SpinInfo *curspin = &s->spin[env_idx];
 132     uint8_t *curspin_p = (uint8_t*)curspin;
 133
 134     cpu = qemu_get_cpu(env_idx);
 135     if (cpu == NULL) {
 136         /* Unknown CPU */
 137         return;
 138     }
 139
 140     if (cpu->cpu_index == 0) {
 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             .cpu = POWERPC_CPU(cpu),
 162             .spin = curspin,
 163         };
 164
 165         run_on_cpu(cpu, spin_kick, &kick);
 166     }
 167 }
 168
 169 static uint64_t spin_read(void *opaque, hwaddr 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 = E500_SPIN(dev);
 195
 196     memory_region_init_io(&s->iomem, OBJECT(s), &spin_rw_ops, s,
 197                           "e500 spin pv device", sizeof(SpinInfo) * MAX_CPUS);
 198     sysbus_init_mmio(dev, &s->iomem);
 199
 200     qemu_register_reset(spin_reset, s);
 201
 202     return 0;
 203 }
 204
 205 static void ppce500_spin_class_init(ObjectClass *klass, void *data)
 206 {
 207     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 208
 209     k->init = ppce500_spin_initfn;
 210 }
 211
 212 static const TypeInfo ppce500_spin_info = {
 213     .name          = TYPE_E500_SPIN,
 214     .parent        = TYPE_SYS_BUS_DEVICE,
 215     .instance_size = sizeof(SpinState),
 216     .class_init    = ppce500_spin_class_init,
 217 };
 218
 219 static void ppce500_spin_register_types(void)
 220 {
 221     type_register_static(&ppce500_spin_info);
 222 }
 223
 224 type_init(ppce500_spin_register_types)