1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * New-style PCI core.
4 *
5 * Copyright (c) 2004 - 2009 Paul Mundt
6 * Copyright (c) 2002 M. R. Brown
7 *
8 * Modelled after arch/mips/pci/pci.c:
9 * Copyright (C) 2003, 04 Ralf Baechle (ralf@linux-mips.org)
10 */
11 #include <linux/kernel.h>
12 #include <linux/mm.h>
13 #include <linux/pci.h>
14 #include <linux/init.h>
15 #include <linux/types.h>
16 #include <linux/io.h>
17 #include <linux/mutex.h>
18 #include <linux/spinlock.h>
19 #include <linux/export.h>
20
21 unsigned long PCIBIOS_MIN_IO = 0x0000;
22 unsigned long PCIBIOS_MIN_MEM = 0;
23
24 /*
25 * The PCI controller list.
26 */
27 static struct pci_channel *hose_head, **hose_tail = &hose_head;
28
29 static int pci_initialized;
30
31 static void pcibios_scanbus(struct pci_channel *hose)
32 {
33 static int next_busno;
34 static int need_domain_info;
35 LIST_HEAD(resources);
36 struct resource *res;
37 resource_size_t offset;
38 int i, ret;
39 struct pci_host_bridge *bridge;
40
41 bridge = pci_alloc_host_bridge(0);
42 if (!bridge)
43 return;
44
45 for (i = 0; i < hose->nr_resources; i++) {
46 res = hose->resources + i;
47 offset = 0;
48 if (res->flags & IORESOURCE_DISABLED)
49 continue;
50 if (res->flags & IORESOURCE_IO)
51 offset = hose->io_offset;
52 else if (res->flags & IORESOURCE_MEM)
53 offset = hose->mem_offset;
54 pci_add_resource_offset(&resources, res, offset);
55 }
56
57 list_splice_init(&resources, &bridge->windows);
58 bridge->dev.parent = NULL;
59 bridge->sysdata = hose;
60 bridge->busnr = next_busno;
61 bridge->ops = hose->pci_ops;
62 bridge->swizzle_irq = pci_common_swizzle;
63 bridge->map_irq = pcibios_map_platform_irq;
64
65 ret = pci_scan_root_bus_bridge(bridge);
66 if (ret) {
67 pci_free_host_bridge(bridge);
68 return;
69 }
70
71 hose->bus = bridge->bus;
72
73 need_domain_info = need_domain_info || hose->index;
74 hose->need_domain_info = need_domain_info;
75
76 next_busno = hose->bus->busn_res.end + 1;
77 /* Don't allow 8-bit bus number overflow inside the hose -
78 reserve some space for bridges. */
79 if (next_busno > 224) {
80 next_busno = 0;
81 need_domain_info = 1;
82 }
83
84 pci_bus_size_bridges(hose->bus);
85 pci_bus_assign_resources(hose->bus);
86 pci_bus_add_devices(hose->bus);
87 }
88
89 /*
90 * This interrupt-safe spinlock protects all accesses to PCI
91 * configuration space.
92 */
93 DEFINE_RAW_SPINLOCK(pci_config_lock);
94 static DEFINE_MUTEX(pci_scan_mutex);
95
96 int register_pci_controller(struct pci_channel *hose)
97 {
98 int i;
99
100 for (i = 0; i < hose->nr_resources; i++) {
101 struct resource *res = hose->resources + i;
102
103 if (res->flags & IORESOURCE_DISABLED)
104 continue;
105
106 if (res->flags & IORESOURCE_IO) {
107 if (request_resource(&ioport_resource, res) < 0)
108 goto out;
109 } else {
110 if (request_resource(&iomem_resource, res) < 0)
111 goto out;
112 }
113 }
114
115 *hose_tail = hose;
116 hose_tail = &hose->next;
117
118 /*
119 * Do not panic here but later - this might happen before console init.
120 */
121 if (!hose->io_map_base) {
122 pr_warn("registering PCI controller with io_map_base unset\n");
123 }
124
125 /*
126 * Setup the ERR/PERR and SERR timers, if available.
127 */
128 pcibios_enable_timers(hose);
129
130 /*
131 * Scan the bus if it is register after the PCI subsystem
132 * initialization.
133 */
134 if (pci_initialized) {
135 mutex_lock(&pci_scan_mutex);
136 pcibios_scanbus(hose);
137 mutex_unlock(&pci_scan_mutex);
138 }
139
140 return 0;
141
142 out:
143 for (--i; i >= 0; i--)
144 release_resource(&hose->resources[i]);
145
146 pr_warn("Skipping PCI bus scan due to resource conflict\n");
147 return -1;
148 }
149
150 static int __init pcibios_init(void)
151 {
152 struct pci_channel *hose;
153
154 /* Scan all of the recorded PCI controllers. */
155 for (hose = hose_head; hose; hose = hose->next)
156 pcibios_scanbus(hose);
157
158 pci_initialized = 1;
159
160 return 0;
161 }
162 subsys_initcall(pcibios_init);
163
164 /*
165 * We need to avoid collisions with `mirrored' VGA ports
166 * and other strange ISA hardware, so we always want the
167 * addresses to be allocated in the 0x000-0x0ff region
168 * modulo 0x400.
169 */
170 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
171 resource_size_t size, resource_size_t align)
172 {
173 struct pci_dev *dev = data;
174 struct pci_channel *hose = dev->sysdata;
175 resource_size_t start = res->start;
176
177 if (res->flags & IORESOURCE_IO) {
178 if (start < PCIBIOS_MIN_IO + hose->resources[0].start)
179 start = PCIBIOS_MIN_IO + hose->resources[0].start;
180
181 /*
182 * Put everything into 0x00-0xff region modulo 0x400.
183 */
184 if (start & 0x300)
185 start = (start + 0x3ff) & ~0x3ff;
186 }
187
188 return start;
189 }
190
191 static void __init
192 pcibios_bus_report_status_early(struct pci_channel *hose,
193 int top_bus, int current_bus,
194 unsigned int status_mask, int warn)
195 {
196 unsigned int pci_devfn;
197 u16 status;
198 int ret;
199
200 for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
201 if (PCI_FUNC(pci_devfn))
202 continue;
203 ret = early_read_config_word(hose, top_bus, current_bus,
204 pci_devfn, PCI_STATUS, &status);
205 if (ret != PCIBIOS_SUCCESSFUL)
206 continue;
207 if (status == 0xffff)
208 continue;
209
210 early_write_config_word(hose, top_bus, current_bus,
211 pci_devfn, PCI_STATUS,
212 status & status_mask);
213 if (warn)
214 pr_cont("(%02x:%02x: %04X) ", current_bus, pci_devfn,
215 status);
216 }
217 }
218
219 /*
220 * We can't use pci_find_device() here since we are
221 * called from interrupt context.
222 */
223 static void __ref
224 pcibios_bus_report_status(struct pci_bus *bus, unsigned int status_mask,
225 int warn)
226 {
227 struct pci_dev *dev;
228
229 list_for_each_entry(dev, &bus->devices, bus_list) {
230 u16 status;
231
232 /*
233 * ignore host bridge - we handle
234 * that separately
235 */
236 if (dev->bus->number == 0 && dev->devfn == 0)
237 continue;
238
239 pci_read_config_word(dev, PCI_STATUS, &status);
240 if (status == 0xffff)
241 continue;
242
243 if ((status & status_mask) == 0)
244 continue;
245
246 /* clear the status errors */
247 pci_write_config_word(dev, PCI_STATUS, status & status_mask);
248
249 if (warn)
250 pr_cont("(%s: %04X) ", pci_name(dev), status);
251 }
252
253 list_for_each_entry(dev, &bus->devices, bus_list)
254 if (dev->subordinate)
255 pcibios_bus_report_status(dev->subordinate, status_mask, warn);
256 }
257
258 void __ref pcibios_report_status(unsigned int status_mask, int warn)
259 {
260 struct pci_channel *hose;
261
262 for (hose = hose_head; hose; hose = hose->next) {
263 if (unlikely(!hose->bus))
264 pcibios_bus_report_status_early(hose, hose_head->index,
265 hose->index, status_mask, warn);
266 else
267 pcibios_bus_report_status(hose->bus, status_mask, warn);
268 }
269 }
270
271 #ifndef CONFIG_GENERIC_IOMAP
272
273 void __iomem *__pci_ioport_map(struct pci_dev *dev,
274 unsigned long port, unsigned int nr)
275 {
276 struct pci_channel *chan = dev->sysdata;
277
278 if (unlikely(!chan->io_map_base)) {
279 chan->io_map_base = sh_io_port_base;
280
281 if (pci_domains_supported)
282 panic("To avoid data corruption io_map_base MUST be "
283 "set with multiple PCI domains.");
284 }
285
286 return (void __iomem *)(chan->io_map_base + port);
287 }
288
289 void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
290 {
291 iounmap(addr);
292 }
293 EXPORT_SYMBOL(pci_iounmap);
294
295 #endif /* CONFIG_GENERIC_IOMAP */
296
297 EXPORT_SYMBOL(PCIBIOS_MIN_IO);
298 EXPORT_SYMBOL(PCIBIOS_MIN_MEM);
299
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