xref: /openbmc/qemu/hw/ppc/rs6000_mc.c (revision 59a3a1c0)
1 /*
2  * QEMU RS/6000 memory controller
3  *
4  * Copyright (c) 2017 Hervé Poussineau
5  *
6  * This program is free software: you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation, either version 2 of the License, or
9  * (at your option) version 3 or any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qemu/units.h"
22 #include "hw/isa/isa.h"
23 #include "hw/qdev-properties.h"
24 #include "migration/vmstate.h"
25 #include "exec/address-spaces.h"
26 #include "hw/boards.h"
27 #include "qapi/error.h"
28 #include "trace.h"
29 
30 #define TYPE_RS6000MC "rs6000-mc"
31 #define RS6000MC_DEVICE(obj) \
32     OBJECT_CHECK(RS6000MCState, (obj), TYPE_RS6000MC)
33 
34 typedef struct RS6000MCState {
35     ISADevice parent_obj;
36     /* see US patent 5,684,979 for details (expired 2001-11-04) */
37     uint32_t ram_size;
38     bool autoconfigure;
39     MemoryRegion simm[6];
40     unsigned int simm_size[6];
41     uint32_t end_address[8];
42     uint8_t port0820_index;
43     PortioList portio;
44 } RS6000MCState;
45 
46 /* P0RT 0803 -- SIMM ID Register (32/8 MB) (Read Only) */
47 
48 static uint32_t rs6000mc_port0803_read(void *opaque, uint32_t addr)
49 {
50     RS6000MCState *s = opaque;
51     uint32_t val = 0;
52     int socket;
53 
54     /* (1 << socket) indicates 32 MB SIMM at given socket */
55     for (socket = 0; socket < 6; socket++) {
56         if (s->simm_size[socket] == 32) {
57             val |= (1 << socket);
58         }
59     }
60 
61     trace_rs6000mc_id_read(addr, val);
62     return val;
63 }
64 
65 /* PORT 0804 -- SIMM Presence Register (Read Only) */
66 
67 static uint32_t rs6000mc_port0804_read(void *opaque, uint32_t addr)
68 {
69     RS6000MCState *s = opaque;
70     uint32_t val = 0xff;
71     int socket;
72 
73     /* (1 << socket) indicates SIMM absence at given socket */
74     for (socket = 0; socket < 6; socket++) {
75         if (s->simm_size[socket]) {
76             val &= ~(1 << socket);
77         }
78     }
79     s->port0820_index = 0;
80 
81     trace_rs6000mc_presence_read(addr, val);
82     return val;
83 }
84 
85 /* Memory Controller Size Programming Register */
86 
87 static uint32_t rs6000mc_port0820_read(void *opaque, uint32_t addr)
88 {
89     RS6000MCState *s = opaque;
90     uint32_t val = s->end_address[s->port0820_index] & 0x1f;
91     s->port0820_index = (s->port0820_index + 1) & 7;
92     trace_rs6000mc_size_read(addr, val);
93     return val;
94 }
95 
96 static void rs6000mc_port0820_write(void *opaque, uint32_t addr, uint32_t val)
97 {
98     RS6000MCState *s = opaque;
99     uint8_t socket = val >> 5;
100     uint32_t end_address = val & 0x1f;
101 
102     trace_rs6000mc_size_write(addr, val);
103     s->end_address[socket] = end_address;
104     if (socket > 0 && socket < 7) {
105         if (s->simm_size[socket - 1]) {
106             uint32_t size;
107             uint32_t start_address = 0;
108             if (socket > 1) {
109                 start_address = s->end_address[socket - 1];
110             }
111 
112             size = end_address - start_address;
113             memory_region_set_enabled(&s->simm[socket - 1], size != 0);
114             memory_region_set_address(&s->simm[socket - 1],
115                                       start_address * 8 * MiB);
116         }
117     }
118 }
119 
120 /* Read Memory Parity Error */
121 
122 enum {
123     PORT0841_NO_ERROR_DETECTED = 0x01,
124 };
125 
126 static uint32_t rs6000mc_port0841_read(void *opaque, uint32_t addr)
127 {
128     uint32_t val = PORT0841_NO_ERROR_DETECTED;
129     trace_rs6000mc_parity_read(addr, val);
130     return val;
131 }
132 
133 static const MemoryRegionPortio rs6000mc_port_list[] = {
134     { 0x803, 1, 1, .read = rs6000mc_port0803_read },
135     { 0x804, 1, 1, .read = rs6000mc_port0804_read },
136     { 0x820, 1, 1, .read = rs6000mc_port0820_read,
137                    .write = rs6000mc_port0820_write, },
138     { 0x841, 1, 1, .read = rs6000mc_port0841_read },
139     PORTIO_END_OF_LIST()
140 };
141 
142 static void rs6000mc_realize(DeviceState *dev, Error **errp)
143 {
144     RS6000MCState *s = RS6000MC_DEVICE(dev);
145     int socket = 0;
146     unsigned int ram_size = s->ram_size / MiB;
147 
148     while (socket < 6) {
149         if (ram_size >= 64) {
150             s->simm_size[socket] = 32;
151             s->simm_size[socket + 1] = 32;
152             ram_size -= 64;
153         } else if (ram_size >= 16) {
154             s->simm_size[socket] = 8;
155             s->simm_size[socket + 1] = 8;
156             ram_size -= 16;
157         } else {
158             /* Not enough memory */
159             break;
160         }
161         socket += 2;
162     }
163 
164     for (socket = 0; socket < 6; socket++) {
165         if (s->simm_size[socket]) {
166             char name[] = "simm.?";
167             name[5] = socket + '0';
168             memory_region_allocate_system_memory(&s->simm[socket], OBJECT(dev),
169                                                  name,
170                                                  s->simm_size[socket] * MiB);
171             memory_region_add_subregion_overlap(get_system_memory(), 0,
172                                                 &s->simm[socket], socket);
173         }
174     }
175     if (ram_size) {
176         /* unable to push all requested RAM in SIMMs */
177         error_setg(errp, "RAM size incompatible with this board. "
178                    "Try again with something else, like %" PRId64 " MB",
179                    s->ram_size / MiB - ram_size);
180         return;
181     }
182 
183     if (s->autoconfigure) {
184         uint32_t start_address = 0;
185         for (socket = 0; socket < 6; socket++) {
186             if (s->simm_size[socket]) {
187                 memory_region_set_enabled(&s->simm[socket], true);
188                 memory_region_set_address(&s->simm[socket], start_address);
189                 start_address += memory_region_size(&s->simm[socket]);
190             }
191         }
192     }
193 
194     isa_register_portio_list(ISA_DEVICE(dev), &s->portio, 0x0,
195                              rs6000mc_port_list, s, "rs6000mc");
196 }
197 
198 static const VMStateDescription vmstate_rs6000mc = {
199     .name = "rs6000-mc",
200     .version_id = 1,
201     .minimum_version_id = 1,
202     .fields = (VMStateField[]) {
203         VMSTATE_UINT8(port0820_index, RS6000MCState),
204         VMSTATE_END_OF_LIST()
205     },
206 };
207 
208 static Property rs6000mc_properties[] = {
209     DEFINE_PROP_UINT32("ram-size", RS6000MCState, ram_size, 0),
210     DEFINE_PROP_BOOL("auto-configure", RS6000MCState, autoconfigure, true),
211     DEFINE_PROP_END_OF_LIST()
212 };
213 
214 static void rs6000mc_class_initfn(ObjectClass *klass, void *data)
215 {
216     DeviceClass *dc = DEVICE_CLASS(klass);
217 
218     dc->realize = rs6000mc_realize;
219     dc->vmsd = &vmstate_rs6000mc;
220     dc->props = rs6000mc_properties;
221 }
222 
223 static const TypeInfo rs6000mc_info = {
224     .name          = TYPE_RS6000MC,
225     .parent        = TYPE_ISA_DEVICE,
226     .instance_size = sizeof(RS6000MCState),
227     .class_init    = rs6000mc_class_initfn,
228 };
229 
230 static void rs6000mc_types(void)
231 {
232     type_register_static(&rs6000mc_info);
233 }
234 
235 type_init(rs6000mc_types)
236