aboutsummaryrefslogtreecommitdiff
path: root/hw/ppce500_spin.c
blob: 5bdce52e24e79fae58c3e66fd662141b8f84dccd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
/*
 * QEMU PowerPC e500v2 ePAPR spinning code
 *
 * Copyright (C) 2011 Freescale Semiconductor, Inc. All rights reserved.
 *
 * Author: Alexander Graf, <agraf@suse.de>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 *
 * This code is not really a device, but models an interface that usually
 * firmware takes care of. It's used when QEMU plays the role of firmware.
 *
 * Specification:
 *
 * https://www.power.org/resources/downloads/Power_ePAPR_APPROVED_v1.1.pdf
 *
 */

#include "hw.h"
#include "sysemu/sysemu.h"
#include "sysbus.h"
#include "sysemu/kvm.h"

#define MAX_CPUS 32

typedef struct spin_info {
    uint64_t addr;
    uint64_t r3;
    uint32_t resv;
    uint32_t pir;
    uint64_t reserved;
} QEMU_PACKED SpinInfo;

typedef struct spin_state {
    SysBusDevice busdev;
    MemoryRegion iomem;
    SpinInfo spin[MAX_CPUS];
} SpinState;

typedef struct spin_kick {
    PowerPCCPU *cpu;
    SpinInfo *spin;
} SpinKick;

static void spin_reset(void *opaque)
{
    SpinState *s = opaque;
    int i;

    for (i = 0; i < MAX_CPUS; i++) {
        SpinInfo *info = &s->spin[i];

        info->pir = i;
        info->r3 = i;
        info->addr = 1;
    }
}

/* Create -kernel TLB entries for BookE, linearly spanning 256MB.  */
static inline hwaddr booke206_page_size_to_tlb(uint64_t size)
{
    return (ffs(size >> 10) - 1) >> 1;
}

static void mmubooke_create_initial_mapping(CPUPPCState *env,
                                     target_ulong va,
                                     hwaddr pa,
                                     hwaddr len)
{
    ppcmas_tlb_t *tlb = booke206_get_tlbm(env, 1, 0, 1);
    hwaddr size;

    size = (booke206_page_size_to_tlb(len) << MAS1_TSIZE_SHIFT);
    tlb->mas1 = MAS1_VALID | size;
    tlb->mas2 = (va & TARGET_PAGE_MASK) | MAS2_M;
    tlb->mas7_3 = pa & TARGET_PAGE_MASK;
    tlb->mas7_3 |= MAS3_UR | MAS3_UW | MAS3_UX | MAS3_SR | MAS3_SW | MAS3_SX;
    env->tlb_dirty = true;
}

static void spin_kick(void *data)
{
    SpinKick *kick = data;
    CPUState *cpu = CPU(kick->cpu);
    CPUPPCState *env = &kick->cpu->env;
    SpinInfo *curspin = kick->spin;
    hwaddr map_size = 64 * 1024 * 1024;
    hwaddr map_start;

    cpu_synchronize_state(env);
    stl_p(&curspin->pir, env->spr[SPR_PIR]);
    env->nip = ldq_p(&curspin->addr) & (map_size - 1);
    env->gpr[3] = ldq_p(&curspin->r3);
    env->gpr[4] = 0;
    env->gpr[5] = 0;
    env->gpr[6] = 0;
    env->gpr[7] = map_size;
    env->gpr[8] = 0;
    env->gpr[9] = 0;

    map_start = ldq_p(&curspin->addr) & ~(map_size - 1);
    mmubooke_create_initial_mapping(env, 0, map_start, map_size);

    env->halted = 0;
    env->exception_index = -1;
    cpu->stopped = false;
    qemu_cpu_kick(cpu);
}

static void spin_write(void *opaque, hwaddr addr, uint64_t value,
                       unsigned len)
{
    SpinState *s = opaque;
    int env_idx = addr / sizeof(SpinInfo);
    CPUState *cpu;
    SpinInfo *curspin = &s->spin[env_idx];
    uint8_t *curspin_p = (uint8_t*)curspin;

    cpu = qemu_get_cpu(env_idx);
    if (cpu == NULL) {
        /* Unknown CPU */
        return;
    }

    if (cpu->cpu_index == 0) {
        /* primary CPU doesn't spin */
        return;
    }

    curspin_p = &curspin_p[addr % sizeof(SpinInfo)];
    switch (len) {
    case 1:
        stb_p(curspin_p, value);
        break;
    case 2:
        stw_p(curspin_p, value);
        break;
    case 4:
        stl_p(curspin_p, value);
        break;
    }

    if (!(ldq_p(&curspin->addr) & 1)) {
        /* run CPU */
        SpinKick kick = {
            .cpu = POWERPC_CPU(cpu),
            .spin = curspin,
        };

        run_on_cpu(cpu, spin_kick, &kick);
    }
}

static uint64_t spin_read(void *opaque, hwaddr addr, unsigned len)
{
    SpinState *s = opaque;
    uint8_t *spin_p = &((uint8_t*)s->spin)[addr];

    switch (len) {
    case 1:
        return ldub_p(spin_p);
    case 2:
        return lduw_p(spin_p);
    case 4:
        return ldl_p(spin_p);
    default:
        hw_error("ppce500: unexpected %s with len = %u", __func__, len);
    }
}

static const MemoryRegionOps spin_rw_ops = {
    .read = spin_read,
    .write = spin_write,
    .endianness = DEVICE_BIG_ENDIAN,
};

static int ppce500_spin_initfn(SysBusDevice *dev)
{
    SpinState *s;

    s = FROM_SYSBUS(SpinState, SYS_BUS_DEVICE(dev));

    memory_region_init_io(&s->iomem, &spin_rw_ops, s, "e500 spin pv device",
                          sizeof(SpinInfo) * MAX_CPUS);
    sysbus_init_mmio(dev, &s->iomem);

    qemu_register_reset(spin_reset, s);

    return 0;
}

static void ppce500_spin_class_init(ObjectClass *klass, void *data)
{
    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);

    k->init = ppce500_spin_initfn;
}

static const TypeInfo ppce500_spin_info = {
    .name          = "e500-spin",
    .parent        = TYPE_SYS_BUS_DEVICE,
    .instance_size = sizeof(SpinState),
    .class_init    = ppce500_spin_class_init,
};

static void ppce500_spin_register_types(void)
{
    type_register_static(&ppce500_spin_info);
}

type_init(ppce500_spin_register_types)