hw/pci-host/pam.c

   1 /*
   2  * QEMU Smram/pam logic implementation
   3  *
   4  * Copyright (c) 2006 Fabrice Bellard
   5  * Copyright (c) 2011 Isaku Yamahata <yamahata at valinux co jp>
   6  *                    VA Linux Systems Japan K.K.
   7  * Copyright (c) 2012 Jason Baron <jbaron@redhat.com>
   8  *
   9  * Split out from piix.c
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  24  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  25  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  26  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  27  * THE SOFTWARE.
  28  */
  29
  30 #include "qemu/osdep.h"
  31 #include "hw/pci-host/pam.h"
  32
  33 void init_pam(DeviceState *dev, MemoryRegion *ram_memory,
  34               MemoryRegion *system_memory, MemoryRegion *pci_address_space,
  35               PAMMemoryRegion *mem, uint32_t start, uint32_t size)
  36 {
  37     int i;
  38
  39     /* RAM */
  40     memory_region_init_alias(&mem->alias[3], OBJECT(dev), "pam-ram", ram_memory,
  41                              start, size);
  42     /* ROM (XXX: not quite correct) */
  43     memory_region_init_alias(&mem->alias[1], OBJECT(dev), "pam-rom", ram_memory,
  44                              start, size);
  45     memory_region_set_readonly(&mem->alias[1], true);
  46
  47     /* XXX: should distinguish read/write cases */
  48     memory_region_init_alias(&mem->alias[0], OBJECT(dev), "pam-pci", pci_address_space,
  49                              start, size);
  50     memory_region_init_alias(&mem->alias[2], OBJECT(dev), "pam-pci", ram_memory,
  51                              start, size);
  52
  53     memory_region_transaction_begin();
  54     for (i = 0; i < 4; ++i) {
  55         memory_region_set_enabled(&mem->alias[i], false);
  56         memory_region_add_subregion_overlap(system_memory, start,
  57                                             &mem->alias[i], 1);
  58     }
  59     memory_region_transaction_commit();
  60     mem->current = 0;
  61 }
  62
  63 void pam_update(PAMMemoryRegion *pam, int idx, uint8_t val)
  64 {
  65     assert(0 <= idx && idx <= 12);
  66
  67     memory_region_set_enabled(&pam->alias[pam->current], false);
  68     pam->current = (val >> ((!(idx & 1)) * 4)) & PAM_ATTR_MASK;
  69     memory_region_set_enabled(&pam->alias[pam->current], true);
  70 }