xref: /openbmc/qemu/hw/ppc/ppce500_spin.c (revision 48151859)
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 "qemu/osdep.h"
31 #include "hw/hw.h"
32 #include "sysemu/sysemu.h"
33 #include "hw/sysbus.h"
34 #include "sysemu/kvm.h"
35 #include "e500.h"
36 
37 #define MAX_CPUS 32
38 
39 typedef struct spin_info {
40     uint64_t addr;
41     uint64_t r3;
42     uint32_t resv;
43     uint32_t pir;
44     uint64_t reserved;
45 } QEMU_PACKED SpinInfo;
46 
47 #define TYPE_E500_SPIN "e500-spin"
48 #define E500_SPIN(obj) OBJECT_CHECK(SpinState, (obj), TYPE_E500_SPIN)
49 
50 typedef struct SpinState {
51     SysBusDevice parent_obj;
52 
53     MemoryRegion iomem;
54     SpinInfo spin[MAX_CPUS];
55 } SpinState;
56 
57 typedef struct spin_kick {
58     PowerPCCPU *cpu;
59     SpinInfo *spin;
60 } SpinKick;
61 
62 static void spin_reset(void *opaque)
63 {
64     SpinState *s = opaque;
65     int i;
66 
67     for (i = 0; i < MAX_CPUS; i++) {
68         SpinInfo *info = &s->spin[i];
69 
70         stl_p(&info->pir, i);
71         stq_p(&info->r3, i);
72         stq_p(&info->addr, 1);
73     }
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(cpu);
102     stl_p(&curspin->pir, env->spr[SPR_BOOKE_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     cpu->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 = E500_SPIN(dev);
191 
192     memory_region_init_io(&s->iomem, OBJECT(s), &spin_rw_ops, s,
193                           "e500 spin pv device", sizeof(SpinInfo) * MAX_CPUS);
194     sysbus_init_mmio(dev, &s->iomem);
195 
196     qemu_register_reset(spin_reset, s);
197 
198     return 0;
199 }
200 
201 static void ppce500_spin_class_init(ObjectClass *klass, void *data)
202 {
203     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
204 
205     k->init = ppce500_spin_initfn;
206 }
207 
208 static const TypeInfo ppce500_spin_info = {
209     .name          = TYPE_E500_SPIN,
210     .parent        = TYPE_SYS_BUS_DEVICE,
211     .instance_size = sizeof(SpinState),
212     .class_init    = ppce500_spin_class_init,
213 };
214 
215 static void ppce500_spin_register_types(void)
216 {
217     type_register_static(&ppce500_spin_info);
218 }
219 
220 type_init(ppce500_spin_register_types)
221