1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Routines for tracking a legacy ISA bridge |
4 | * |
5 | * Copyrigh 2007 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp. |
6 | * |
7 | * Some bits and pieces moved over from pci_64.c |
8 | * |
9 | * Copyrigh 2003 Anton Blanchard <anton@au.ibm.com>, IBM Corp. |
10 | */ |
11 | |
12 | #define DEBUG |
13 | |
14 | #include <linux/kernel.h> |
15 | #include <linux/pci.h> |
16 | #include <linux/string.h> |
17 | #include <linux/export.h> |
18 | #include <linux/init.h> |
19 | #include <linux/mm.h> |
20 | #include <linux/notifier.h> |
21 | #include <linux/of_address.h> |
22 | #include <linux/vmalloc.h> |
23 | |
24 | #include <asm/processor.h> |
25 | #include <asm/io.h> |
26 | #include <asm/pci-bridge.h> |
27 | #include <asm/machdep.h> |
28 | #include <asm/ppc-pci.h> |
29 | #include <asm/isa-bridge.h> |
30 | |
31 | unsigned long isa_io_base; /* NULL if no ISA bus */ |
32 | EXPORT_SYMBOL(isa_io_base); |
33 | |
34 | /* Cached ISA bridge dev. */ |
35 | static struct device_node *isa_bridge_devnode; |
36 | struct pci_dev *isa_bridge_pcidev; |
37 | EXPORT_SYMBOL_GPL(isa_bridge_pcidev); |
38 | |
39 | #define ISA_SPACE_MASK 0x1 |
40 | #define ISA_SPACE_IO 0x1 |
41 | |
42 | static void remap_isa_base(phys_addr_t pa, unsigned long size) |
43 | { |
44 | WARN_ON_ONCE(ISA_IO_BASE & ~PAGE_MASK); |
45 | WARN_ON_ONCE(pa & ~PAGE_MASK); |
46 | WARN_ON_ONCE(size & ~PAGE_MASK); |
47 | |
48 | if (slab_is_available()) { |
49 | if (vmap_page_range(addr: ISA_IO_BASE, end: ISA_IO_BASE + size, phys_addr: pa, |
50 | pgprot_noncached(PAGE_KERNEL))) |
51 | vunmap_range(addr: ISA_IO_BASE, end: ISA_IO_BASE + size); |
52 | } else { |
53 | early_ioremap_range(ISA_IO_BASE, pa, size, |
54 | pgprot_noncached(PAGE_KERNEL)); |
55 | } |
56 | } |
57 | |
58 | static int process_ISA_OF_ranges(struct device_node *isa_node, |
59 | unsigned long phb_io_base_phys) |
60 | { |
61 | unsigned int size; |
62 | struct of_range_parser parser; |
63 | struct of_range range; |
64 | |
65 | if (of_range_parser_init(parser: &parser, node: isa_node)) |
66 | goto inval_range; |
67 | |
68 | for_each_of_range(&parser, &range) { |
69 | if ((range.flags & ISA_SPACE_MASK) != ISA_SPACE_IO) |
70 | continue; |
71 | |
72 | if (range.cpu_addr == OF_BAD_ADDR) { |
73 | pr_err("ISA: Bad CPU mapping: %s\n" , __func__); |
74 | return -EINVAL; |
75 | } |
76 | |
77 | /* We need page alignment */ |
78 | if ((range.bus_addr & ~PAGE_MASK) || (range.cpu_addr & ~PAGE_MASK)) { |
79 | pr_warn("ISA: bridge %pOF has non aligned IO range\n" , isa_node); |
80 | return -EINVAL; |
81 | } |
82 | |
83 | /* Align size and make sure it's cropped to 64K */ |
84 | size = PAGE_ALIGN(range.size); |
85 | if (size > 0x10000) |
86 | size = 0x10000; |
87 | |
88 | if (!phb_io_base_phys) |
89 | phb_io_base_phys = range.cpu_addr; |
90 | |
91 | remap_isa_base(pa: phb_io_base_phys, size); |
92 | return 0; |
93 | } |
94 | |
95 | inval_range: |
96 | if (phb_io_base_phys) { |
97 | pr_err("no ISA IO ranges or unexpected isa range, mapping 64k\n" ); |
98 | remap_isa_base(pa: phb_io_base_phys, size: 0x10000); |
99 | return 0; |
100 | } |
101 | return -EINVAL; |
102 | } |
103 | |
104 | |
105 | /** |
106 | * isa_bridge_find_early - Find and map the ISA IO space early before |
107 | * main PCI discovery. This is optionally called by |
108 | * the arch code when adding PCI PHBs to get early |
109 | * access to ISA IO ports |
110 | */ |
111 | void __init isa_bridge_find_early(struct pci_controller *hose) |
112 | { |
113 | struct device_node *np, *parent = NULL, *tmp; |
114 | |
115 | /* If we already have an ISA bridge, bail off */ |
116 | if (isa_bridge_devnode != NULL) |
117 | return; |
118 | |
119 | /* For each "isa" node in the system. Note : we do a search by |
120 | * type and not by name. It might be better to do by name but that's |
121 | * what the code used to do and I don't want to break too much at |
122 | * once. We can look into changing that separately |
123 | */ |
124 | for_each_node_by_type(np, "isa" ) { |
125 | /* Look for our hose being a parent */ |
126 | for (parent = of_get_parent(node: np); parent;) { |
127 | if (parent == hose->dn) { |
128 | of_node_put(node: parent); |
129 | break; |
130 | } |
131 | tmp = parent; |
132 | parent = of_get_parent(node: parent); |
133 | of_node_put(node: tmp); |
134 | } |
135 | if (parent != NULL) |
136 | break; |
137 | } |
138 | if (np == NULL) |
139 | return; |
140 | isa_bridge_devnode = np; |
141 | |
142 | /* Now parse the "ranges" property and setup the ISA mapping */ |
143 | process_ISA_OF_ranges(isa_node: np, phb_io_base_phys: hose->io_base_phys); |
144 | |
145 | /* Set the global ISA io base to indicate we have an ISA bridge */ |
146 | isa_io_base = ISA_IO_BASE; |
147 | |
148 | pr_debug("ISA bridge (early) is %pOF\n" , np); |
149 | } |
150 | |
151 | /** |
152 | * isa_bridge_find_early - Find and map the ISA IO space early before |
153 | * main PCI discovery. This is optionally called by |
154 | * the arch code when adding PCI PHBs to get early |
155 | * access to ISA IO ports |
156 | */ |
157 | void __init isa_bridge_init_non_pci(struct device_node *np) |
158 | { |
159 | int ret; |
160 | |
161 | /* If we already have an ISA bridge, bail off */ |
162 | if (isa_bridge_devnode != NULL) |
163 | return; |
164 | |
165 | ret = process_ISA_OF_ranges(isa_node: np, phb_io_base_phys: 0); |
166 | if (ret) |
167 | return; |
168 | |
169 | /* Got it */ |
170 | isa_bridge_devnode = np; |
171 | |
172 | /* Set the global ISA io base to indicate we have an ISA bridge |
173 | * and map it |
174 | */ |
175 | isa_io_base = ISA_IO_BASE; |
176 | |
177 | pr_debug("ISA: Non-PCI bridge is %pOF\n" , np); |
178 | } |
179 | |
180 | /** |
181 | * isa_bridge_find_late - Find and map the ISA IO space upon discovery of |
182 | * a new ISA bridge |
183 | */ |
184 | static void isa_bridge_find_late(struct pci_dev *pdev, |
185 | struct device_node *devnode) |
186 | { |
187 | struct pci_controller *hose = pci_bus_to_host(pdev->bus); |
188 | |
189 | /* Store ISA device node and PCI device */ |
190 | isa_bridge_devnode = of_node_get(node: devnode); |
191 | isa_bridge_pcidev = pdev; |
192 | |
193 | /* Now parse the "ranges" property and setup the ISA mapping */ |
194 | process_ISA_OF_ranges(isa_node: devnode, phb_io_base_phys: hose->io_base_phys); |
195 | |
196 | /* Set the global ISA io base to indicate we have an ISA bridge */ |
197 | isa_io_base = ISA_IO_BASE; |
198 | |
199 | pr_debug("ISA bridge (late) is %pOF on %s\n" , |
200 | devnode, pci_name(pdev)); |
201 | } |
202 | |
203 | /** |
204 | * isa_bridge_remove - Remove/unmap an ISA bridge |
205 | */ |
206 | static void isa_bridge_remove(void) |
207 | { |
208 | pr_debug("ISA bridge removed !\n" ); |
209 | |
210 | /* Clear the global ISA io base to indicate that we have no more |
211 | * ISA bridge. Note that drivers don't quite handle that, though |
212 | * we should probably do something about it. But do we ever really |
213 | * have ISA bridges being removed on machines using legacy devices ? |
214 | */ |
215 | isa_io_base = ISA_IO_BASE; |
216 | |
217 | /* Clear references to the bridge */ |
218 | of_node_put(node: isa_bridge_devnode); |
219 | isa_bridge_devnode = NULL; |
220 | isa_bridge_pcidev = NULL; |
221 | |
222 | /* Unmap the ISA area */ |
223 | vunmap_range(addr: ISA_IO_BASE, end: ISA_IO_BASE + 0x10000); |
224 | } |
225 | |
226 | /** |
227 | * isa_bridge_notify - Get notified of PCI devices addition/removal |
228 | */ |
229 | static int isa_bridge_notify(struct notifier_block *nb, unsigned long action, |
230 | void *data) |
231 | { |
232 | struct device *dev = data; |
233 | struct pci_dev *pdev = to_pci_dev(dev); |
234 | struct device_node *devnode = pci_device_to_OF_node(pdev); |
235 | |
236 | switch(action) { |
237 | case BUS_NOTIFY_ADD_DEVICE: |
238 | /* Check if we have an early ISA device, without PCI dev */ |
239 | if (isa_bridge_devnode && isa_bridge_devnode == devnode && |
240 | !isa_bridge_pcidev) { |
241 | pr_debug("ISA bridge PCI attached: %s\n" , |
242 | pci_name(pdev)); |
243 | isa_bridge_pcidev = pdev; |
244 | } |
245 | |
246 | /* Check if we have no ISA device, and this happens to be one, |
247 | * register it as such if it has an OF device |
248 | */ |
249 | if (!isa_bridge_devnode && of_node_is_type(np: devnode, type: "isa" )) |
250 | isa_bridge_find_late(pdev, devnode); |
251 | |
252 | return 0; |
253 | case BUS_NOTIFY_DEL_DEVICE: |
254 | /* Check if this our existing ISA device */ |
255 | if (pdev == isa_bridge_pcidev || |
256 | (devnode && devnode == isa_bridge_devnode)) |
257 | isa_bridge_remove(); |
258 | return 0; |
259 | } |
260 | return 0; |
261 | } |
262 | |
263 | static struct notifier_block isa_bridge_notifier = { |
264 | .notifier_call = isa_bridge_notify |
265 | }; |
266 | |
267 | /** |
268 | * isa_bridge_init - register to be notified of ISA bridge addition/removal |
269 | * |
270 | */ |
271 | static int __init isa_bridge_init(void) |
272 | { |
273 | bus_register_notifier(bus: &pci_bus_type, nb: &isa_bridge_notifier); |
274 | return 0; |
275 | } |
276 | arch_initcall(isa_bridge_init); |
277 | |