xref: /openbmc/qemu/hw/pci-host/pam.c (revision 2993683b)
1 /*
2  * QEMU i440FX/PIIX3 PCI Bridge Emulation
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_pci.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 #include "sysemu/sysemu.h"
30 #include "hw/pci-host/pam.h"
31 
32 void smram_update(MemoryRegion *smram_region, uint8_t smram,
33                   uint8_t smm_enabled)
34 {
35     bool smram_enabled;
36 
37     smram_enabled = ((smm_enabled && (smram & SMRAM_G_SMRAME)) ||
38                         (smram & SMRAM_D_OPEN));
39     memory_region_set_enabled(smram_region, !smram_enabled);
40 }
41 
42 void smram_set_smm(uint8_t *host_smm_enabled, int smm, uint8_t smram,
43                    MemoryRegion *smram_region)
44 {
45     uint8_t smm_enabled = (smm != 0);
46     if (*host_smm_enabled != smm_enabled) {
47         *host_smm_enabled = smm_enabled;
48         smram_update(smram_region, smram, *host_smm_enabled);
49     }
50 }
51 
52 void init_pam(MemoryRegion *ram_memory, MemoryRegion *system_memory,
53               MemoryRegion *pci_address_space, PAMMemoryRegion *mem,
54               uint32_t start, uint32_t size)
55 {
56     int i;
57 
58     /* RAM */
59     memory_region_init_alias(&mem->alias[3], "pam-ram", ram_memory,
60                              start, size);
61     /* ROM (XXX: not quite correct) */
62     memory_region_init_alias(&mem->alias[1], "pam-rom", ram_memory,
63                              start, size);
64     memory_region_set_readonly(&mem->alias[1], true);
65 
66     /* XXX: should distinguish read/write cases */
67     memory_region_init_alias(&mem->alias[0], "pam-pci", pci_address_space,
68                              start, size);
69     memory_region_init_alias(&mem->alias[2], "pam-pci", pci_address_space,
70                              start, size);
71 
72     for (i = 0; i < 4; ++i) {
73         memory_region_set_enabled(&mem->alias[i], false);
74         memory_region_add_subregion_overlap(system_memory, start,
75                                             &mem->alias[i], 1);
76     }
77     mem->current = 0;
78 }
79 
80 void pam_update(PAMMemoryRegion *pam, int idx, uint8_t val)
81 {
82     assert(0 <= idx && idx <= 12);
83 
84     memory_region_set_enabled(&pam->alias[pam->current], false);
85     pam->current = (val >> ((!(idx & 1)) * 4)) & PAM_ATTR_MASK;
86     memory_region_set_enabled(&pam->alias[pam->current], true);
87 }
88