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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Support for indirect PCI bridges.
4 *
5 * Copyright (C) 1998 Gabriel Paubert.
6 */
7
8#include <linux/kernel.h>
9#include <linux/pci.h>
10#include <linux/delay.h>
11#include <linux/string.h>
12#include <linux/init.h>
13
14#include <asm/io.h>
15#include <asm/pci-bridge.h>
16#include <asm/machdep.h>
17
18int __indirect_read_config(struct pci_controller *hose,
19 unsigned char bus_number, unsigned int devfn,
20 int offset, int len, u32 *val)
21{
22 volatile void __iomem *cfg_data;
23 u8 cfg_type = 0;
24 u32 bus_no, reg;
25
26 if (hose->indirect_type & PPC_INDIRECT_TYPE_NO_PCIE_LINK) {
27 if (bus_number != hose->first_busno)
28 return PCIBIOS_DEVICE_NOT_FOUND;
29 if (devfn != 0)
30 return PCIBIOS_DEVICE_NOT_FOUND;
31 }
32
33 if (ppc_md.pci_exclude_device)
34 if (ppc_md.pci_exclude_device(hose, bus_number, devfn))
35 return PCIBIOS_DEVICE_NOT_FOUND;
36
37 if (hose->indirect_type & PPC_INDIRECT_TYPE_SET_CFG_TYPE)
38 if (bus_number != hose->first_busno)
39 cfg_type = 1;
40
41 bus_no = (bus_number == hose->first_busno) ?
42 hose->self_busno : bus_number;
43
44 if (hose->indirect_type & PPC_INDIRECT_TYPE_EXT_REG)
45 reg = ((offset & 0xf00) << 16) | (offset & 0xfc);
46 else
47 reg = offset & 0xfc;
48
49 if (hose->indirect_type & PPC_INDIRECT_TYPE_BIG_ENDIAN)
50 out_be32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
51 (devfn << 8) | reg | cfg_type));
52 else
53 out_le32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
54 (devfn << 8) | reg | cfg_type));
55
56 /*
57 * Note: the caller has already checked that offset is
58 * suitably aligned and that len is 1, 2 or 4.
59 */
60 cfg_data = hose->cfg_data + (offset & 3);
61 switch (len) {
62 case 1:
63 *val = in_8(cfg_data);
64 break;
65 case 2:
66 *val = in_le16(cfg_data);
67 break;
68 default:
69 *val = in_le32(cfg_data);
70 break;
71 }
72 return PCIBIOS_SUCCESSFUL;
73}
74
75int indirect_read_config(struct pci_bus *bus, unsigned int devfn,
76 int offset, int len, u32 *val)
77{
78 struct pci_controller *hose = pci_bus_to_host(bus);
79
80 return __indirect_read_config(hose, bus->number, devfn, offset, len,
81 val);
82}
83
84int indirect_write_config(struct pci_bus *bus, unsigned int devfn,
85 int offset, int len, u32 val)
86{
87 struct pci_controller *hose = pci_bus_to_host(bus);
88 volatile void __iomem *cfg_data;
89 u8 cfg_type = 0;
90 u32 bus_no, reg;
91
92 if (hose->indirect_type & PPC_INDIRECT_TYPE_NO_PCIE_LINK) {
93 if (bus->number != hose->first_busno)
94 return PCIBIOS_DEVICE_NOT_FOUND;
95 if (devfn != 0)
96 return PCIBIOS_DEVICE_NOT_FOUND;
97 }
98
99 if (ppc_md.pci_exclude_device)
100 if (ppc_md.pci_exclude_device(hose, bus->number, devfn))
101 return PCIBIOS_DEVICE_NOT_FOUND;
102
103 if (hose->indirect_type & PPC_INDIRECT_TYPE_SET_CFG_TYPE)
104 if (bus->number != hose->first_busno)
105 cfg_type = 1;
106
107 bus_no = (bus->number == hose->first_busno) ?
108 hose->self_busno : bus->number;
109
110 if (hose->indirect_type & PPC_INDIRECT_TYPE_EXT_REG)
111 reg = ((offset & 0xf00) << 16) | (offset & 0xfc);
112 else
113 reg = offset & 0xfc;
114
115 if (hose->indirect_type & PPC_INDIRECT_TYPE_BIG_ENDIAN)
116 out_be32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
117 (devfn << 8) | reg | cfg_type));
118 else
119 out_le32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
120 (devfn << 8) | reg | cfg_type));
121
122 /* suppress setting of PCI_PRIMARY_BUS */
123 if (hose->indirect_type & PPC_INDIRECT_TYPE_SURPRESS_PRIMARY_BUS)
124 if ((offset == PCI_PRIMARY_BUS) &&
125 (bus->number == hose->first_busno))
126 val &= 0xffffff00;
127
128 /* Workaround for PCI_28 Errata in 440EPx/GRx */
129 if ((hose->indirect_type & PPC_INDIRECT_TYPE_BROKEN_MRM) &&
130 offset == PCI_CACHE_LINE_SIZE) {
131 val = 0;
132 }
133
134 /*
135 * Note: the caller has already checked that offset is
136 * suitably aligned and that len is 1, 2 or 4.
137 */
138 cfg_data = hose->cfg_data + (offset & 3);
139 switch (len) {
140 case 1:
141 out_8(cfg_data, val);
142 break;
143 case 2:
144 out_le16(cfg_data, val);
145 break;
146 default:
147 out_le32(cfg_data, val);
148 break;
149 }
150 return PCIBIOS_SUCCESSFUL;
151}
152
153static struct pci_ops indirect_pci_ops =
154{
155 .read = indirect_read_config,
156 .write = indirect_write_config,
157};
158
159void setup_indirect_pci(struct pci_controller *hose, resource_size_t cfg_addr,
160 resource_size_t cfg_data, u32 flags)
161{
162 resource_size_t base = cfg_addr & PAGE_MASK;
163 void __iomem *mbase;
164
165 mbase = ioremap(base, PAGE_SIZE);
166 hose->cfg_addr = mbase + (cfg_addr & ~PAGE_MASK);
167 if ((cfg_data & PAGE_MASK) != base)
168 mbase = ioremap(cfg_data & PAGE_MASK, PAGE_SIZE);
169 hose->cfg_data = mbase + (cfg_data & ~PAGE_MASK);
170 hose->ops = &indirect_pci_ops;
171 hose->indirect_type = flags;
172}