xref: /openbmc/qemu/hw/pci-host/pam.c (revision da054c64)
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 "qom/object.h"
32 #include "sysemu/sysemu.h"
33 #include "hw/pci-host/pam.h"
34 
35 void init_pam(DeviceState *dev, MemoryRegion *ram_memory,
36               MemoryRegion *system_memory, MemoryRegion *pci_address_space,
37               PAMMemoryRegion *mem, uint32_t start, uint32_t size)
38 {
39     int i;
40 
41     /* RAM */
42     memory_region_init_alias(&mem->alias[3], OBJECT(dev), "pam-ram", ram_memory,
43                              start, size);
44     /* ROM (XXX: not quite correct) */
45     memory_region_init_alias(&mem->alias[1], OBJECT(dev), "pam-rom", ram_memory,
46                              start, size);
47     memory_region_set_readonly(&mem->alias[1], true);
48 
49     /* XXX: should distinguish read/write cases */
50     memory_region_init_alias(&mem->alias[0], OBJECT(dev), "pam-pci", pci_address_space,
51                              start, size);
52     memory_region_init_alias(&mem->alias[2], OBJECT(dev), "pam-pci", ram_memory,
53                              start, size);
54 
55     memory_region_transaction_begin();
56     for (i = 0; i < 4; ++i) {
57         memory_region_set_enabled(&mem->alias[i], false);
58         memory_region_add_subregion_overlap(system_memory, start,
59                                             &mem->alias[i], 1);
60     }
61     memory_region_transaction_commit();
62     mem->current = 0;
63 }
64 
65 void pam_update(PAMMemoryRegion *pam, int idx, uint8_t val)
66 {
67     assert(0 <= idx && idx <= 12);
68 
69     memory_region_set_enabled(&pam->alias[pam->current], false);
70     pam->current = (val >> ((!(idx & 1)) * 4)) & PAM_ATTR_MASK;
71     memory_region_set_enabled(&pam->alias[pam->current], true);
72 }
73