xref: /linux/arch/powerpc/sysdev/indirect_pci.c (revision 564eb714f5f09ac733c26860d5f0831f213fbdf1)
1 /*
2  * Support for indirect PCI bridges.
3  *
4  * Copyright (C) 1998 Gabriel Paubert.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/pci.h>
14 #include <linux/delay.h>
15 #include <linux/string.h>
16 #include <linux/init.h>
17 
18 #include <asm/io.h>
19 #include <asm/prom.h>
20 #include <asm/pci-bridge.h>
21 #include <asm/machdep.h>
22 
23 int indirect_read_config(struct pci_bus *bus, unsigned int devfn,
24 			 int offset, int len, u32 *val)
25 {
26 	struct pci_controller *hose = pci_bus_to_host(bus);
27 	volatile void __iomem *cfg_data;
28 	u8 cfg_type = 0;
29 	u32 bus_no, reg;
30 
31 	if (hose->indirect_type & PPC_INDIRECT_TYPE_NO_PCIE_LINK) {
32 		if (bus->number != hose->first_busno)
33 			return PCIBIOS_DEVICE_NOT_FOUND;
34 		if (devfn != 0)
35 			return PCIBIOS_DEVICE_NOT_FOUND;
36 	}
37 
38 	if (ppc_md.pci_exclude_device)
39 		if (ppc_md.pci_exclude_device(hose, bus->number, devfn))
40 			return PCIBIOS_DEVICE_NOT_FOUND;
41 
42 	if (hose->indirect_type & PPC_INDIRECT_TYPE_SET_CFG_TYPE)
43 		if (bus->number != hose->first_busno)
44 			cfg_type = 1;
45 
46 	bus_no = (bus->number == hose->first_busno) ?
47 			hose->self_busno : bus->number;
48 
49 	if (hose->indirect_type & PPC_INDIRECT_TYPE_EXT_REG)
50 		reg = ((offset & 0xf00) << 16) | (offset & 0xfc);
51 	else
52 		reg = offset & 0xfc;
53 
54 	if (hose->indirect_type & PPC_INDIRECT_TYPE_BIG_ENDIAN)
55 		out_be32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
56 			 (devfn << 8) | reg | cfg_type));
57 	else
58 		out_le32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
59 			 (devfn << 8) | reg | cfg_type));
60 
61 	/*
62 	 * Note: the caller has already checked that offset is
63 	 * suitably aligned and that len is 1, 2 or 4.
64 	 */
65 	cfg_data = hose->cfg_data + (offset & 3);
66 	switch (len) {
67 	case 1:
68 		*val = in_8(cfg_data);
69 		break;
70 	case 2:
71 		*val = in_le16(cfg_data);
72 		break;
73 	default:
74 		*val = in_le32(cfg_data);
75 		break;
76 	}
77 	return PCIBIOS_SUCCESSFUL;
78 }
79 
80 int indirect_write_config(struct pci_bus *bus, unsigned int devfn,
81 			  int offset, int len, u32 val)
82 {
83 	struct pci_controller *hose = pci_bus_to_host(bus);
84 	volatile void __iomem *cfg_data;
85 	u8 cfg_type = 0;
86 	u32 bus_no, reg;
87 
88 	if (hose->indirect_type & PPC_INDIRECT_TYPE_NO_PCIE_LINK) {
89 		if (bus->number != hose->first_busno)
90 			return PCIBIOS_DEVICE_NOT_FOUND;
91 		if (devfn != 0)
92 			return PCIBIOS_DEVICE_NOT_FOUND;
93 	}
94 
95 	if (ppc_md.pci_exclude_device)
96 		if (ppc_md.pci_exclude_device(hose, bus->number, devfn))
97 			return PCIBIOS_DEVICE_NOT_FOUND;
98 
99 	if (hose->indirect_type & PPC_INDIRECT_TYPE_SET_CFG_TYPE)
100 		if (bus->number != hose->first_busno)
101 			cfg_type = 1;
102 
103 	bus_no = (bus->number == hose->first_busno) ?
104 			hose->self_busno : bus->number;
105 
106 	if (hose->indirect_type & PPC_INDIRECT_TYPE_EXT_REG)
107 		reg = ((offset & 0xf00) << 16) | (offset & 0xfc);
108 	else
109 		reg = offset & 0xfc;
110 
111 	if (hose->indirect_type & PPC_INDIRECT_TYPE_BIG_ENDIAN)
112 		out_be32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
113 			 (devfn << 8) | reg | cfg_type));
114 	else
115 		out_le32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
116 			 (devfn << 8) | reg | cfg_type));
117 
118 	/* suppress setting of PCI_PRIMARY_BUS */
119 	if (hose->indirect_type & PPC_INDIRECT_TYPE_SURPRESS_PRIMARY_BUS)
120 		if ((offset == PCI_PRIMARY_BUS) &&
121 			(bus->number == hose->first_busno))
122 		val &= 0xffffff00;
123 
124 	/* Workaround for PCI_28 Errata in 440EPx/GRx */
125 	if ((hose->indirect_type & PPC_INDIRECT_TYPE_BROKEN_MRM) &&
126 			offset == PCI_CACHE_LINE_SIZE) {
127 		val = 0;
128 	}
129 
130 	/*
131 	 * Note: the caller has already checked that offset is
132 	 * suitably aligned and that len is 1, 2 or 4.
133 	 */
134 	cfg_data = hose->cfg_data + (offset & 3);
135 	switch (len) {
136 	case 1:
137 		out_8(cfg_data, val);
138 		break;
139 	case 2:
140 		out_le16(cfg_data, val);
141 		break;
142 	default:
143 		out_le32(cfg_data, val);
144 		break;
145 	}
146 	return PCIBIOS_SUCCESSFUL;
147 }
148 
149 static struct pci_ops indirect_pci_ops =
150 {
151 	.read = indirect_read_config,
152 	.write = indirect_write_config,
153 };
154 
155 void __init
156 setup_indirect_pci(struct pci_controller* hose,
157 		   resource_size_t cfg_addr,
158 		   resource_size_t cfg_data, u32 flags)
159 {
160 	resource_size_t base = cfg_addr & PAGE_MASK;
161 	void __iomem *mbase;
162 
163 	mbase = ioremap(base, PAGE_SIZE);
164 	hose->cfg_addr = mbase + (cfg_addr & ~PAGE_MASK);
165 	if ((cfg_data & PAGE_MASK) != base)
166 		mbase = ioremap(cfg_data & PAGE_MASK, PAGE_SIZE);
167 	hose->cfg_data = mbase + (cfg_data & ~PAGE_MASK);
168 	hose->ops = &indirect_pci_ops;
169 	hose->indirect_type = flags;
170 }
171