xref: /openbmc/qemu/hw/pci/pcie_host.c (revision 38dc1294)
1 /*
2  * pcie_host.c
3  * utility functions for pci express host bridge.
4  *
5  * Copyright (c) 2009 Isaku Yamahata <yamahata at valinux co jp>
6  *                    VA Linux Systems Japan K.K.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12 
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17 
18  * You should have received a copy of the GNU General Public License along
19  * with this program; if not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 #include "qemu/osdep.h"
23 #include "hw/hw.h"
24 #include "hw/pci/pci.h"
25 #include "hw/pci/pcie_host.h"
26 #include "exec/address-spaces.h"
27 
28 /* a helper function to get a PCIDevice for a given mmconfig address */
29 static inline PCIDevice *pcie_dev_find_by_mmcfg_addr(PCIBus *s,
30                                                      uint32_t mmcfg_addr)
31 {
32     return pci_find_device(s, PCIE_MMCFG_BUS(mmcfg_addr),
33                            PCIE_MMCFG_DEVFN(mmcfg_addr));
34 }
35 
36 static void pcie_mmcfg_data_write(void *opaque, hwaddr mmcfg_addr,
37                                   uint64_t val, unsigned len)
38 {
39     PCIExpressHost *e = opaque;
40     PCIBus *s = e->pci.bus;
41     PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr);
42     uint32_t addr;
43     uint32_t limit;
44 
45     if (!pci_dev) {
46         return;
47     }
48     addr = PCIE_MMCFG_CONFOFFSET(mmcfg_addr);
49     limit = pci_config_size(pci_dev);
50     pci_host_config_write_common(pci_dev, addr, limit, val, len);
51 }
52 
53 static uint64_t pcie_mmcfg_data_read(void *opaque,
54                                      hwaddr mmcfg_addr,
55                                      unsigned len)
56 {
57     PCIExpressHost *e = opaque;
58     PCIBus *s = e->pci.bus;
59     PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr);
60     uint32_t addr;
61     uint32_t limit;
62 
63     if (!pci_dev) {
64         return ~0x0;
65     }
66     addr = PCIE_MMCFG_CONFOFFSET(mmcfg_addr);
67     limit = pci_config_size(pci_dev);
68     return pci_host_config_read_common(pci_dev, addr, limit, len);
69 }
70 
71 static const MemoryRegionOps pcie_mmcfg_ops = {
72     .read = pcie_mmcfg_data_read,
73     .write = pcie_mmcfg_data_write,
74     .endianness = DEVICE_LITTLE_ENDIAN,
75 };
76 
77 static void pcie_host_init(Object *obj)
78 {
79     PCIExpressHost *e = PCIE_HOST_BRIDGE(obj);
80 
81     e->base_addr = PCIE_BASE_ADDR_UNMAPPED;
82     memory_region_init_io(&e->mmio, OBJECT(e), &pcie_mmcfg_ops, e, "pcie-mmcfg-mmio",
83                           PCIE_MMCFG_SIZE_MAX);
84 }
85 
86 void pcie_host_mmcfg_unmap(PCIExpressHost *e)
87 {
88     if (e->base_addr != PCIE_BASE_ADDR_UNMAPPED) {
89         memory_region_del_subregion(get_system_memory(), &e->mmio);
90         e->base_addr = PCIE_BASE_ADDR_UNMAPPED;
91     }
92 }
93 
94 void pcie_host_mmcfg_init(PCIExpressHost *e, uint32_t size)
95 {
96     assert(!(size & (size - 1)));       /* power of 2 */
97     assert(size >= PCIE_MMCFG_SIZE_MIN);
98     assert(size <= PCIE_MMCFG_SIZE_MAX);
99     e->size = size;
100     memory_region_set_size(&e->mmio, e->size);
101 }
102 
103 void pcie_host_mmcfg_map(PCIExpressHost *e, hwaddr addr,
104                          uint32_t size)
105 {
106     pcie_host_mmcfg_init(e, size);
107     e->base_addr = addr;
108     memory_region_add_subregion(get_system_memory(), e->base_addr, &e->mmio);
109 }
110 
111 void pcie_host_mmcfg_update(PCIExpressHost *e,
112                             int enable,
113                             hwaddr addr,
114                             uint32_t size)
115 {
116     memory_region_transaction_begin();
117     pcie_host_mmcfg_unmap(e);
118     if (enable) {
119         pcie_host_mmcfg_map(e, addr, size);
120     }
121     memory_region_transaction_commit();
122 }
123 
124 static const TypeInfo pcie_host_type_info = {
125     .name = TYPE_PCIE_HOST_BRIDGE,
126     .parent = TYPE_PCI_HOST_BRIDGE,
127     .abstract = true,
128     .instance_size = sizeof(PCIExpressHost),
129     .instance_init = pcie_host_init,
130 };
131 
132 static void pcie_host_register_types(void)
133 {
134     type_register_static(&pcie_host_type_info);
135 }
136 
137 type_init(pcie_host_register_types)
138