qemu

rs6000_mc.c (7071B)

---

 /*
  * QEMU RS/6000 memory controller
  *
  * Copyright (c) 2017 Hervé Poussineau
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 2 of the License, or
  * (at your option) version 3 or any later version.
  *
  * This program 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 General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include "qemu/osdep.h"
 #include "qemu/units.h"
 #include "hw/isa/isa.h"
 #include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
 #include "exec/address-spaces.h"
 #include "qapi/error.h"
 #include "trace.h"
 #include "qom/object.h"
 
 #define TYPE_RS6000MC "rs6000-mc"
 OBJECT_DECLARE_SIMPLE_TYPE(RS6000MCState, RS6000MC)
 
 struct RS6000MCState {
     ISADevice parent_obj;
     /* see US patent 5,684,979 for details (expired 2001-11-04) */
     uint32_t ram_size;
     bool autoconfigure;
     MemoryRegion simm[6];
     unsigned int simm_size[6];
     uint32_t end_address[8];
     uint8_t port0820_index;
     PortioList portio;
 };
 
 /* P0RT 0803 -- SIMM ID Register (32/8 MB) (Read Only) */
 
 static uint32_t rs6000mc_port0803_read(void *opaque, uint32_t addr)
 {
     RS6000MCState *s = opaque;
     uint32_t val = 0;
     int socket;
 
     /* (1 << socket) indicates 32 MB SIMM at given socket */
     for (socket = 0; socket < 6; socket++) {
         if (s->simm_size[socket] == 32) {
             val |= (1 << socket);
         }
     }
 
     trace_rs6000mc_id_read(addr, val);
     return val;
 }
 
 /* PORT 0804 -- SIMM Presence Register (Read Only) */
 
 static uint32_t rs6000mc_port0804_read(void *opaque, uint32_t addr)
 {
     RS6000MCState *s = opaque;
     uint32_t val = 0xff;
     int socket;
 
     /* (1 << socket) indicates SIMM absence at given socket */
     for (socket = 0; socket < 6; socket++) {
         if (s->simm_size[socket]) {
             val &= ~(1 << socket);
         }
     }
     s->port0820_index = 0;
 
     trace_rs6000mc_presence_read(addr, val);
     return val;
 }
 
 /* Memory Controller Size Programming Register */
 
 static uint32_t rs6000mc_port0820_read(void *opaque, uint32_t addr)
 {
     RS6000MCState *s = opaque;
     uint32_t val = s->end_address[s->port0820_index] & 0x1f;
     s->port0820_index = (s->port0820_index + 1) & 7;
     trace_rs6000mc_size_read(addr, val);
     return val;
 }
 
 static void rs6000mc_port0820_write(void *opaque, uint32_t addr, uint32_t val)
 {
     RS6000MCState *s = opaque;
     uint8_t socket = val >> 5;
     uint32_t end_address = val & 0x1f;
 
     trace_rs6000mc_size_write(addr, val);
     s->end_address[socket] = end_address;
     if (socket > 0 && socket < 7) {
         if (s->simm_size[socket - 1]) {
             uint32_t size;
             uint32_t start_address = 0;
             if (socket > 1) {
                 start_address = s->end_address[socket - 1];
             }
 
             size = end_address - start_address;
             memory_region_set_enabled(&s->simm[socket - 1], size != 0);
             memory_region_set_address(&s->simm[socket - 1],
                                       start_address * 8 * MiB);
         }
     }
 }
 
 /* Read Memory Parity Error */
 
 enum {
     PORT0841_NO_ERROR_DETECTED = 0x01,
 };
 
 static uint32_t rs6000mc_port0841_read(void *opaque, uint32_t addr)
 {
     uint32_t val = PORT0841_NO_ERROR_DETECTED;
     trace_rs6000mc_parity_read(addr, val);
     return val;
 }
 
 static const MemoryRegionPortio rs6000mc_port_list[] = {
     { 0x803, 1, 1, .read = rs6000mc_port0803_read },
     { 0x804, 1, 1, .read = rs6000mc_port0804_read },
     { 0x820, 1, 1, .read = rs6000mc_port0820_read,
                    .write = rs6000mc_port0820_write, },
     { 0x841, 1, 1, .read = rs6000mc_port0841_read },
     PORTIO_END_OF_LIST()
 };
 
 static void rs6000mc_realize(DeviceState *dev, Error **errp)
 {
     RS6000MCState *s = RS6000MC(dev);
     int socket = 0;
     unsigned int ram_size = s->ram_size / MiB;
     Error *local_err = NULL;
 
     while (socket < 6) {
         if (ram_size >= 64) {
             s->simm_size[socket] = 32;
             s->simm_size[socket + 1] = 32;
             ram_size -= 64;
         } else if (ram_size >= 16) {
             s->simm_size[socket] = 8;
             s->simm_size[socket + 1] = 8;
             ram_size -= 16;
         } else {
             /* Not enough memory */
             break;
         }
         socket += 2;
     }
 
     for (socket = 0; socket < 6; socket++) {
         if (s->simm_size[socket]) {
             char name[] = "simm.?";
             name[5] = socket + '0';
             memory_region_init_ram(&s->simm[socket], OBJECT(dev), name,
                                    s->simm_size[socket] * MiB, &local_err);
             if (local_err) {
                 error_propagate(errp, local_err);
                 return;
             }
             memory_region_add_subregion_overlap(get_system_memory(), 0,
                                                 &s->simm[socket], socket);
         }
     }
     if (ram_size) {
         /* unable to push all requested RAM in SIMMs */
         error_setg(errp, "RAM size incompatible with this board. "
                    "Try again with something else, like %" PRId64 " MB",
                    s->ram_size / MiB - ram_size);
         return;
     }
 
     if (s->autoconfigure) {
         uint32_t start_address = 0;
         for (socket = 0; socket < 6; socket++) {
             if (s->simm_size[socket]) {
                 memory_region_set_enabled(&s->simm[socket], true);
                 memory_region_set_address(&s->simm[socket], start_address);
                 start_address += memory_region_size(&s->simm[socket]);
             }
         }
     }
 
     isa_register_portio_list(ISA_DEVICE(dev), &s->portio, 0x0,
                              rs6000mc_port_list, s, "rs6000mc");
 }
 
 static const VMStateDescription vmstate_rs6000mc = {
     .name = "rs6000-mc",
     .version_id = 1,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(port0820_index, RS6000MCState),
         VMSTATE_END_OF_LIST()
     },
 };
 
 static Property rs6000mc_properties[] = {
     DEFINE_PROP_UINT32("ram-size", RS6000MCState, ram_size, 0),
     DEFINE_PROP_BOOL("auto-configure", RS6000MCState, autoconfigure, true),
     DEFINE_PROP_END_OF_LIST()
 };
 
 static void rs6000mc_class_initfn(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     dc->realize = rs6000mc_realize;
     dc->vmsd = &vmstate_rs6000mc;
     device_class_set_props(dc, rs6000mc_properties);
 }
 
 static const TypeInfo rs6000mc_info = {
     .name          = TYPE_RS6000MC,
     .parent        = TYPE_ISA_DEVICE,
     .instance_size = sizeof(RS6000MCState),
     .class_init    = rs6000mc_class_initfn,
 };
 
 static void rs6000mc_types(void)
 {
     type_register_static(&rs6000mc_info);
 }
 
 type_init(rs6000mc_types)