hw/ppc/rs6000_mc.c

   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     Error *local_err = NULL;
 148
 149     while (socket < 6) {
 150         if (ram_size >= 64) {
 151             s->simm_size[socket] = 32;
 152             s->simm_size[socket + 1] = 32;
 153             ram_size -= 64;
 154         } else if (ram_size >= 16) {
 155             s->simm_size[socket] = 8;
 156             s->simm_size[socket + 1] = 8;
 157             ram_size -= 16;
 158         } else {
 159             /* Not enough memory */
 160             break;
 161         }
 162         socket += 2;
 163     }
 164
 165     for (socket = 0; socket < 6; socket++) {
 166         if (s->simm_size[socket]) {
 167             char name[] = "simm.?";
 168             name[5] = socket + '0';
 169             memory_region_init_ram(&s->simm[socket], OBJECT(dev), name,
 170                                    s->simm_size[socket] * MiB, &local_err);
 171             if (local_err) {
 172                 error_propagate(errp, local_err);
 173                 return;
 174             }
 175             memory_region_add_subregion_overlap(get_system_memory(), 0,
 176                                                 &s->simm[socket], socket);
 177         }
 178     }
 179     if (ram_size) {
 180         /* unable to push all requested RAM in SIMMs */
 181         error_setg(errp, "RAM size incompatible with this board. "
 182                    "Try again with something else, like %" PRId64 " MB",
 183                    s->ram_size / MiB - ram_size);
 184         return;
 185     }
 186
 187     if (s->autoconfigure) {
 188         uint32_t start_address = 0;
 189         for (socket = 0; socket < 6; socket++) {
 190             if (s->simm_size[socket]) {
 191                 memory_region_set_enabled(&s->simm[socket], true);
 192                 memory_region_set_address(&s->simm[socket], start_address);
 193                 start_address += memory_region_size(&s->simm[socket]);
 194             }
 195         }
 196     }
 197
 198     isa_register_portio_list(ISA_DEVICE(dev), &s->portio, 0x0,
 199                              rs6000mc_port_list, s, "rs6000mc");
 200 }
 201
 202 static const VMStateDescription vmstate_rs6000mc = {
 203     .name = "rs6000-mc",
 204     .version_id = 1,
 205     .minimum_version_id = 1,
 206     .fields = (VMStateField[]) {
 207         VMSTATE_UINT8(port0820_index, RS6000MCState),
 208         VMSTATE_END_OF_LIST()
 209     },
 210 };
 211
 212 static Property rs6000mc_properties[] = {
 213     DEFINE_PROP_UINT32("ram-size", RS6000MCState, ram_size, 0),
 214     DEFINE_PROP_BOOL("auto-configure", RS6000MCState, autoconfigure, true),
 215     DEFINE_PROP_END_OF_LIST()
 216 };
 217
 218 static void rs6000mc_class_initfn(ObjectClass *klass, void *data)
 219 {
 220     DeviceClass *dc = DEVICE_CLASS(klass);
 221
 222     dc->realize = rs6000mc_realize;
 223     dc->vmsd = &vmstate_rs6000mc;
 224     device_class_set_props(dc, rs6000mc_properties);
 225 }
 226
 227 static const TypeInfo rs6000mc_info = {
 228     .name          = TYPE_RS6000MC,
 229     .parent        = TYPE_ISA_DEVICE,
 230     .instance_size = sizeof(RS6000MCState),
 231     .class_init    = rs6000mc_class_initfn,
 232 };
 233
 234 static void rs6000mc_types(void)
 235 {
 236     type_register_static(&rs6000mc_info);
 237 }
 238
 239 type_init(rs6000mc_types)