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3d5134ee BH |
1 | /* |
2 | * Routines for tracking a legacy ISA bridge | |
3 | * | |
4 | * Copyrigh 2007 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp. | |
5 | * | |
6 | * Some bits and pieces moved over from pci_64.c | |
7 | * | |
8 | * Copyrigh 2003 Anton Blanchard <anton@au.ibm.com>, IBM Corp. | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or (at your option) any later version. | |
14 | */ | |
15 | ||
16 | #define DEBUG | |
17 | ||
18 | #include <linux/kernel.h> | |
19 | #include <linux/pci.h> | |
20 | #include <linux/string.h> | |
21 | #include <linux/init.h> | |
22 | #include <linux/mm.h> | |
23 | #include <linux/notifier.h> | |
24 | ||
25 | #include <asm/processor.h> | |
26 | #include <asm/io.h> | |
27 | #include <asm/prom.h> | |
28 | #include <asm/pci-bridge.h> | |
29 | #include <asm/machdep.h> | |
30 | #include <asm/ppc-pci.h> | |
31 | #include <asm/firmware.h> | |
32 | ||
33 | unsigned long isa_io_base; /* NULL if no ISA bus */ | |
34 | EXPORT_SYMBOL(isa_io_base); | |
35 | ||
36 | /* Cached ISA bridge dev. */ | |
37 | static struct device_node *isa_bridge_devnode; | |
38 | struct pci_dev *isa_bridge_pcidev; | |
39 | EXPORT_SYMBOL_GPL(isa_bridge_pcidev); | |
40 | ||
41 | #define ISA_SPACE_MASK 0x1 | |
42 | #define ISA_SPACE_IO 0x1 | |
43 | ||
44 | static void __devinit pci_process_ISA_OF_ranges(struct device_node *isa_node, | |
45 | unsigned long phb_io_base_phys) | |
46 | { | |
47 | /* We should get some saner parsing here and remove these structs */ | |
48 | struct pci_address { | |
49 | u32 a_hi; | |
50 | u32 a_mid; | |
51 | u32 a_lo; | |
52 | }; | |
53 | ||
54 | struct isa_address { | |
55 | u32 a_hi; | |
56 | u32 a_lo; | |
57 | }; | |
58 | ||
59 | struct isa_range { | |
60 | struct isa_address isa_addr; | |
61 | struct pci_address pci_addr; | |
62 | unsigned int size; | |
63 | }; | |
64 | ||
65 | const struct isa_range *range; | |
66 | unsigned long pci_addr; | |
67 | unsigned int isa_addr; | |
68 | unsigned int size; | |
69 | int rlen = 0; | |
70 | ||
71 | range = of_get_property(isa_node, "ranges", &rlen); | |
72 | if (range == NULL || (rlen < sizeof(struct isa_range))) | |
73 | goto inval_range; | |
74 | ||
75 | /* From "ISA Binding to 1275" | |
76 | * The ranges property is laid out as an array of elements, | |
77 | * each of which comprises: | |
78 | * cells 0 - 1: an ISA address | |
79 | * cells 2 - 4: a PCI address | |
80 | * (size depending on dev->n_addr_cells) | |
81 | * cell 5: the size of the range | |
82 | */ | |
4df4441e | 83 | if ((range->isa_addr.a_hi & ISA_SPACE_MASK) != ISA_SPACE_IO) { |
3d5134ee BH |
84 | range++; |
85 | rlen -= sizeof(struct isa_range); | |
86 | if (rlen < sizeof(struct isa_range)) | |
87 | goto inval_range; | |
88 | } | |
4df4441e | 89 | if ((range->isa_addr.a_hi & ISA_SPACE_MASK) != ISA_SPACE_IO) |
3d5134ee BH |
90 | goto inval_range; |
91 | ||
92 | isa_addr = range->isa_addr.a_lo; | |
93 | pci_addr = (unsigned long) range->pci_addr.a_mid << 32 | | |
94 | range->pci_addr.a_lo; | |
95 | ||
96 | /* Assume these are both zero. Note: We could fix that and | |
97 | * do a proper parsing instead ... oh well, that will do for | |
98 | * now as nobody uses fancy mappings for ISA bridges | |
99 | */ | |
100 | if ((pci_addr != 0) || (isa_addr != 0)) { | |
101 | printk(KERN_ERR "unexpected isa to pci mapping: %s\n", | |
e48b1b45 | 102 | __func__); |
3d5134ee BH |
103 | return; |
104 | } | |
105 | ||
106 | /* Align size and make sure it's cropped to 64K */ | |
107 | size = PAGE_ALIGN(range->size); | |
108 | if (size > 0x10000) | |
109 | size = 0x10000; | |
110 | ||
3d5134ee BH |
111 | __ioremap_at(phb_io_base_phys, (void *)ISA_IO_BASE, |
112 | size, _PAGE_NO_CACHE|_PAGE_GUARDED); | |
113 | return; | |
114 | ||
115 | inval_range: | |
df3c9019 | 116 | printk(KERN_ERR "no ISA IO ranges or unexpected isa range, " |
3d5134ee BH |
117 | "mapping 64k\n"); |
118 | __ioremap_at(phb_io_base_phys, (void *)ISA_IO_BASE, | |
119 | 0x10000, _PAGE_NO_CACHE|_PAGE_GUARDED); | |
120 | } | |
121 | ||
122 | ||
123 | /** | |
124 | * isa_bridge_find_early - Find and map the ISA IO space early before | |
125 | * main PCI discovery. This is optionally called by | |
126 | * the arch code when adding PCI PHBs to get early | |
127 | * access to ISA IO ports | |
128 | */ | |
129 | void __init isa_bridge_find_early(struct pci_controller *hose) | |
130 | { | |
131 | struct device_node *np, *parent = NULL, *tmp; | |
132 | ||
133 | /* If we already have an ISA bridge, bail off */ | |
134 | if (isa_bridge_devnode != NULL) | |
135 | return; | |
136 | ||
137 | /* For each "isa" node in the system. Note : we do a search by | |
138 | * type and not by name. It might be better to do by name but that's | |
139 | * what the code used to do and I don't want to break too much at | |
140 | * once. We can look into changing that separately | |
141 | */ | |
142 | for_each_node_by_type(np, "isa") { | |
143 | /* Look for our hose being a parent */ | |
144 | for (parent = of_get_parent(np); parent;) { | |
44ef3390 | 145 | if (parent == hose->dn) { |
3d5134ee BH |
146 | of_node_put(parent); |
147 | break; | |
148 | } | |
149 | tmp = parent; | |
150 | parent = of_get_parent(parent); | |
151 | of_node_put(tmp); | |
152 | } | |
153 | if (parent != NULL) | |
154 | break; | |
155 | } | |
156 | if (np == NULL) | |
157 | return; | |
158 | isa_bridge_devnode = np; | |
159 | ||
160 | /* Now parse the "ranges" property and setup the ISA mapping */ | |
161 | pci_process_ISA_OF_ranges(np, hose->io_base_phys); | |
162 | ||
163 | /* Set the global ISA io base to indicate we have an ISA bridge */ | |
164 | isa_io_base = ISA_IO_BASE; | |
165 | ||
166 | pr_debug("ISA bridge (early) is %s\n", np->full_name); | |
167 | } | |
168 | ||
169 | /** | |
170 | * isa_bridge_find_late - Find and map the ISA IO space upon discovery of | |
171 | * a new ISA bridge | |
172 | */ | |
173 | static void __devinit isa_bridge_find_late(struct pci_dev *pdev, | |
174 | struct device_node *devnode) | |
175 | { | |
176 | struct pci_controller *hose = pci_bus_to_host(pdev->bus); | |
177 | ||
178 | /* Store ISA device node and PCI device */ | |
179 | isa_bridge_devnode = of_node_get(devnode); | |
180 | isa_bridge_pcidev = pdev; | |
181 | ||
182 | /* Now parse the "ranges" property and setup the ISA mapping */ | |
183 | pci_process_ISA_OF_ranges(devnode, hose->io_base_phys); | |
184 | ||
185 | /* Set the global ISA io base to indicate we have an ISA bridge */ | |
186 | isa_io_base = ISA_IO_BASE; | |
187 | ||
188 | pr_debug("ISA bridge (late) is %s on %s\n", | |
189 | devnode->full_name, pci_name(pdev)); | |
190 | } | |
191 | ||
192 | /** | |
193 | * isa_bridge_remove - Remove/unmap an ISA bridge | |
194 | */ | |
195 | static void isa_bridge_remove(void) | |
196 | { | |
197 | pr_debug("ISA bridge removed !\n"); | |
198 | ||
199 | /* Clear the global ISA io base to indicate that we have no more | |
200 | * ISA bridge. Note that drivers don't quite handle that, though | |
201 | * we should probably do something about it. But do we ever really | |
202 | * have ISA bridges being removed on machines using legacy devices ? | |
203 | */ | |
204 | isa_io_base = ISA_IO_BASE; | |
205 | ||
206 | /* Clear references to the bridge */ | |
207 | of_node_put(isa_bridge_devnode); | |
208 | isa_bridge_devnode = NULL; | |
209 | isa_bridge_pcidev = NULL; | |
210 | ||
211 | /* Unmap the ISA area */ | |
212 | __iounmap_at((void *)ISA_IO_BASE, 0x10000); | |
213 | } | |
214 | ||
215 | /** | |
216 | * isa_bridge_notify - Get notified of PCI devices addition/removal | |
217 | */ | |
218 | static int __devinit isa_bridge_notify(struct notifier_block *nb, | |
219 | unsigned long action, void *data) | |
220 | { | |
221 | struct device *dev = data; | |
222 | struct pci_dev *pdev = to_pci_dev(dev); | |
223 | struct device_node *devnode = pci_device_to_OF_node(pdev); | |
224 | ||
225 | switch(action) { | |
226 | case BUS_NOTIFY_ADD_DEVICE: | |
227 | /* Check if we have an early ISA device, without PCI dev */ | |
228 | if (isa_bridge_devnode && isa_bridge_devnode == devnode && | |
229 | !isa_bridge_pcidev) { | |
230 | pr_debug("ISA bridge PCI attached: %s\n", | |
231 | pci_name(pdev)); | |
232 | isa_bridge_pcidev = pdev; | |
233 | } | |
234 | ||
235 | /* Check if we have no ISA device, and this happens to be one, | |
236 | * register it as such if it has an OF device | |
237 | */ | |
238 | if (!isa_bridge_devnode && devnode && devnode->type && | |
239 | !strcmp(devnode->type, "isa")) | |
240 | isa_bridge_find_late(pdev, devnode); | |
241 | ||
242 | return 0; | |
243 | case BUS_NOTIFY_DEL_DEVICE: | |
244 | /* Check if this our existing ISA device */ | |
245 | if (pdev == isa_bridge_pcidev || | |
246 | (devnode && devnode == isa_bridge_devnode)) | |
247 | isa_bridge_remove(); | |
248 | return 0; | |
249 | } | |
250 | return 0; | |
251 | } | |
252 | ||
253 | static struct notifier_block isa_bridge_notifier = { | |
254 | .notifier_call = isa_bridge_notify | |
255 | }; | |
256 | ||
257 | /** | |
258 | * isa_bridge_init - register to be notified of ISA bridge addition/removal | |
259 | * | |
260 | */ | |
261 | static int __init isa_bridge_init(void) | |
262 | { | |
263 | if (firmware_has_feature(FW_FEATURE_ISERIES)) | |
264 | return 0; | |
265 | bus_register_notifier(&pci_bus_type, &isa_bridge_notifier); | |
266 | return 0; | |
267 | } | |
268 | arch_initcall(isa_bridge_init); |