xref: /openbmc/qemu/hw/pci/pcie_host.c (revision b957a1b0)
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 "hw/hw.h"
23 #include "hw/pci/pci.h"
24 #include "hw/pci/pcie_host.h"
25 #include "exec/address-spaces.h"
26 
27 /*
28  * PCI express mmcfig address
29  * bit 20 - 28: bus number
30  * bit 15 - 19: device number
31  * bit 12 - 14: function number
32  * bit  0 - 11: offset in configuration space of a given device
33  */
34 #define PCIE_MMCFG_SIZE_MAX             (1ULL << 28)
35 #define PCIE_MMCFG_SIZE_MIN             (1ULL << 20)
36 #define PCIE_MMCFG_BUS_BIT              20
37 #define PCIE_MMCFG_BUS_MASK             0x1ff
38 #define PCIE_MMCFG_DEVFN_BIT            12
39 #define PCIE_MMCFG_DEVFN_MASK           0xff
40 #define PCIE_MMCFG_CONFOFFSET_MASK      0xfff
41 #define PCIE_MMCFG_BUS(addr)            (((addr) >> PCIE_MMCFG_BUS_BIT) & \
42                                          PCIE_MMCFG_BUS_MASK)
43 #define PCIE_MMCFG_DEVFN(addr)          (((addr) >> PCIE_MMCFG_DEVFN_BIT) & \
44                                          PCIE_MMCFG_DEVFN_MASK)
45 #define PCIE_MMCFG_CONFOFFSET(addr)     ((addr) & PCIE_MMCFG_CONFOFFSET_MASK)
46 
47 
48 /* a helper function to get a PCIDevice for a given mmconfig address */
49 static inline PCIDevice *pcie_dev_find_by_mmcfg_addr(PCIBus *s,
50                                                      uint32_t mmcfg_addr)
51 {
52     return pci_find_device(s, PCIE_MMCFG_BUS(mmcfg_addr),
53                            PCIE_MMCFG_DEVFN(mmcfg_addr));
54 }
55 
56 static void pcie_mmcfg_data_write(void *opaque, hwaddr mmcfg_addr,
57                                   uint64_t val, unsigned len)
58 {
59     PCIExpressHost *e = opaque;
60     PCIBus *s = e->pci.bus;
61     PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr);
62     uint32_t addr;
63     uint32_t limit;
64 
65     if (!pci_dev) {
66         return;
67     }
68     addr = PCIE_MMCFG_CONFOFFSET(mmcfg_addr);
69     limit = pci_config_size(pci_dev);
70     if (limit <= addr) {
71         /* conventional pci device can be behind pcie-to-pci bridge.
72            256 <= addr < 4K has no effects. */
73         return;
74     }
75     pci_host_config_write_common(pci_dev, addr, limit, val, len);
76 }
77 
78 static uint64_t pcie_mmcfg_data_read(void *opaque,
79                                      hwaddr mmcfg_addr,
80                                      unsigned len)
81 {
82     PCIExpressHost *e = opaque;
83     PCIBus *s = e->pci.bus;
84     PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr);
85     uint32_t addr;
86     uint32_t limit;
87 
88     if (!pci_dev) {
89         return ~0x0;
90     }
91     addr = PCIE_MMCFG_CONFOFFSET(mmcfg_addr);
92     limit = pci_config_size(pci_dev);
93     if (limit <= addr) {
94         /* conventional pci device can be behind pcie-to-pci bridge.
95            256 <= addr < 4K has no effects. */
96         return ~0x0;
97     }
98     return pci_host_config_read_common(pci_dev, addr, limit, len);
99 }
100 
101 static const MemoryRegionOps pcie_mmcfg_ops = {
102     .read = pcie_mmcfg_data_read,
103     .write = pcie_mmcfg_data_write,
104     .endianness = DEVICE_NATIVE_ENDIAN,
105 };
106 
107 /* pcie_host::base_addr == PCIE_BASE_ADDR_UNMAPPED when it isn't mapped. */
108 #define PCIE_BASE_ADDR_UNMAPPED  ((hwaddr)-1ULL)
109 
110 int pcie_host_init(PCIExpressHost *e)
111 {
112     e->base_addr = PCIE_BASE_ADDR_UNMAPPED;
113 
114     return 0;
115 }
116 
117 void pcie_host_mmcfg_unmap(PCIExpressHost *e)
118 {
119     if (e->base_addr != PCIE_BASE_ADDR_UNMAPPED) {
120         memory_region_del_subregion(get_system_memory(), &e->mmio);
121         memory_region_destroy(&e->mmio);
122         e->base_addr = PCIE_BASE_ADDR_UNMAPPED;
123     }
124 }
125 
126 void pcie_host_mmcfg_map(PCIExpressHost *e, hwaddr addr,
127                          uint32_t size)
128 {
129     assert(!(size & (size - 1)));       /* power of 2 */
130     assert(size >= PCIE_MMCFG_SIZE_MIN);
131     assert(size <= PCIE_MMCFG_SIZE_MAX);
132     e->size = size;
133     memory_region_init_io(&e->mmio, OBJECT(e), &pcie_mmcfg_ops, e,
134                           "pcie-mmcfg", e->size);
135     e->base_addr = addr;
136     memory_region_add_subregion(get_system_memory(), e->base_addr, &e->mmio);
137 }
138 
139 void pcie_host_mmcfg_update(PCIExpressHost *e,
140                             int enable,
141                             hwaddr addr,
142                             uint32_t size)
143 {
144     pcie_host_mmcfg_unmap(e);
145     if (enable) {
146         pcie_host_mmcfg_map(e, addr, size);
147     }
148 }
149 
150 static const TypeInfo pcie_host_type_info = {
151     .name = TYPE_PCIE_HOST_BRIDGE,
152     .parent = TYPE_PCI_HOST_BRIDGE,
153     .abstract = true,
154     .instance_size = sizeof(PCIExpressHost),
155 };
156 
157 static void pcie_host_register_types(void)
158 {
159     type_register_static(&pcie_host_type_info);
160 }
161 
162 type_init(pcie_host_register_types)
163