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 static int
24 indirect_read_config(struct pci_bus *bus, unsigned int devfn, int offset,
25 		     int len, u32 *val)
26 {
27 	struct pci_controller *hose = pci_bus_to_host(bus);
28 	volatile void __iomem *cfg_data;
29 	u8 cfg_type = 0;
30 	u32 bus_no, reg;
31 
32 	if (hose->indirect_type & PPC_INDIRECT_TYPE_NO_PCIE_LINK) {
33 		if (bus->number != hose->first_busno)
34 			return PCIBIOS_DEVICE_NOT_FOUND;
35 		if (devfn != 0)
36 			return PCIBIOS_DEVICE_NOT_FOUND;
37 	}
38 
39 	if (ppc_md.pci_exclude_device)
40 		if (ppc_md.pci_exclude_device(hose, bus->number, devfn))
41 			return PCIBIOS_DEVICE_NOT_FOUND;
42 
43 	if (hose->indirect_type & PPC_INDIRECT_TYPE_SET_CFG_TYPE)
44 		if (bus->number != hose->first_busno)
45 			cfg_type = 1;
46 
47 	bus_no = (bus->number == hose->first_busno) ?
48 			hose->self_busno : bus->number;
49 
50 	if (hose->indirect_type & PPC_INDIRECT_TYPE_EXT_REG)
51 		reg = ((offset & 0xf00) << 16) | (offset & 0xfc);
52 	else
53 		reg = offset & 0xfc;
54 
55 	if (hose->indirect_type & PPC_INDIRECT_TYPE_BIG_ENDIAN)
56 		out_be32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
57 			 (devfn << 8) | reg | cfg_type));
58 	else
59 		out_le32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
60 			 (devfn << 8) | reg | cfg_type));
61 
62 	/*
63 	 * Note: the caller has already checked that offset is
64 	 * suitably aligned and that len is 1, 2 or 4.
65 	 */
66 	cfg_data = hose->cfg_data + (offset & 3);
67 	switch (len) {
68 	case 1:
69 		*val = in_8(cfg_data);
70 		break;
71 	case 2:
72 		*val = in_le16(cfg_data);
73 		break;
74 	default:
75 		*val = in_le32(cfg_data);
76 		break;
77 	}
78 	return PCIBIOS_SUCCESSFUL;
79 }
80 
81 static int
82 indirect_write_config(struct pci_bus *bus, unsigned int devfn, int offset,
83 		      int len, u32 val)
84 {
85 	struct pci_controller *hose = pci_bus_to_host(bus);
86 	volatile void __iomem *cfg_data;
87 	u8 cfg_type = 0;
88 	u32 bus_no, reg;
89 
90 	if (hose->indirect_type & PPC_INDIRECT_TYPE_NO_PCIE_LINK) {
91 		if (bus->number != hose->first_busno)
92 			return PCIBIOS_DEVICE_NOT_FOUND;
93 		if (devfn != 0)
94 			return PCIBIOS_DEVICE_NOT_FOUND;
95 	}
96 
97 	if (ppc_md.pci_exclude_device)
98 		if (ppc_md.pci_exclude_device(hose, bus->number, devfn))
99 			return PCIBIOS_DEVICE_NOT_FOUND;
100 
101 	if (hose->indirect_type & PPC_INDIRECT_TYPE_SET_CFG_TYPE)
102 		if (bus->number != hose->first_busno)
103 			cfg_type = 1;
104 
105 	bus_no = (bus->number == hose->first_busno) ?
106 			hose->self_busno : bus->number;
107 
108 	if (hose->indirect_type & PPC_INDIRECT_TYPE_EXT_REG)
109 		reg = ((offset & 0xf00) << 16) | (offset & 0xfc);
110 	else
111 		reg = offset & 0xfc;
112 
113 	if (hose->indirect_type & PPC_INDIRECT_TYPE_BIG_ENDIAN)
114 		out_be32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
115 			 (devfn << 8) | reg | cfg_type));
116 	else
117 		out_le32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
118 			 (devfn << 8) | reg | cfg_type));
119 
120 	/* suppress setting of PCI_PRIMARY_BUS */
121 	if (hose->indirect_type & PPC_INDIRECT_TYPE_SURPRESS_PRIMARY_BUS)
122 		if ((offset == PCI_PRIMARY_BUS) &&
123 			(bus->number == hose->first_busno))
124 		val &= 0xffffff00;
125 
126 	/* Workaround for PCI_28 Errata in 440EPx/GRx */
127 	if ((hose->indirect_type & PPC_INDIRECT_TYPE_BROKEN_MRM) &&
128 			offset == PCI_CACHE_LINE_SIZE) {
129 		val = 0;
130 	}
131 
132 	/*
133 	 * Note: the caller has already checked that offset is
134 	 * suitably aligned and that len is 1, 2 or 4.
135 	 */
136 	cfg_data = hose->cfg_data + (offset & 3);
137 	switch (len) {
138 	case 1:
139 		out_8(cfg_data, val);
140 		break;
141 	case 2:
142 		out_le16(cfg_data, val);
143 		break;
144 	default:
145 		out_le32(cfg_data, val);
146 		break;
147 	}
148 	return PCIBIOS_SUCCESSFUL;
149 }
150 
151 static struct pci_ops indirect_pci_ops =
152 {
153 	.read = indirect_read_config,
154 	.write = indirect_write_config,
155 };
156 
157 void __init
158 setup_indirect_pci(struct pci_controller* hose,
159 		   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 }
173