xref: /openbmc/linux/arch/sh/drivers/pci/pci.c (revision 0edff03d)
1 /*
2  * New-style PCI core.
3  *
4  * Copyright (c) 2004 - 2009  Paul Mundt
5  * Copyright (c) 2002  M. R. Brown
6  *
7  * Modelled after arch/mips/pci/pci.c:
8  *  Copyright (C) 2003, 04 Ralf Baechle (ralf@linux-mips.org)
9  *
10  * This file is subject to the terms and conditions of the GNU General Public
11  * License.  See the file "COPYING" in the main directory of this archive
12  * for more details.
13  */
14 #include <linux/kernel.h>
15 #include <linux/mm.h>
16 #include <linux/pci.h>
17 #include <linux/init.h>
18 #include <linux/types.h>
19 #include <linux/dma-debug.h>
20 #include <linux/io.h>
21 #include <linux/mutex.h>
22 #include <linux/spinlock.h>
23 #include <linux/export.h>
24 
25 unsigned long PCIBIOS_MIN_IO = 0x0000;
26 unsigned long PCIBIOS_MIN_MEM = 0;
27 
28 /*
29  * The PCI controller list.
30  */
31 static struct pci_channel *hose_head, **hose_tail = &hose_head;
32 
33 static int pci_initialized;
34 
35 static void pcibios_scanbus(struct pci_channel *hose)
36 {
37 	static int next_busno;
38 	static int need_domain_info;
39 	LIST_HEAD(resources);
40 	struct resource *res;
41 	resource_size_t offset;
42 	int i, ret;
43 	struct pci_host_bridge *bridge;
44 
45 	bridge = pci_alloc_host_bridge(0);
46 	if (!bridge)
47 		return;
48 
49 	for (i = 0; i < hose->nr_resources; i++) {
50 		res = hose->resources + i;
51 		offset = 0;
52 		if (res->flags & IORESOURCE_IO)
53 			offset = hose->io_offset;
54 		else if (res->flags & IORESOURCE_MEM)
55 			offset = hose->mem_offset;
56 		pci_add_resource_offset(&resources, res, offset);
57 	}
58 
59 	list_splice_init(&resources, &bridge->windows);
60 	bridge->dev.parent = NULL;
61 	bridge->sysdata = hose;
62 	bridge->busnr = next_busno;
63 	bridge->ops = hose->pci_ops;
64 	bridge->swizzle_irq = pci_common_swizzle;
65 	bridge->map_irq = pcibios_map_platform_irq;
66 
67 	ret = pci_scan_root_bus_bridge(bridge);
68 	if (ret) {
69 		pci_free_host_bridge(bridge);
70 		return;
71 	}
72 
73 	hose->bus = bridge->bus;
74 
75 	need_domain_info = need_domain_info || hose->index;
76 	hose->need_domain_info = need_domain_info;
77 
78 	next_busno = hose->bus->busn_res.end + 1;
79 	/* Don't allow 8-bit bus number overflow inside the hose -
80 	   reserve some space for bridges. */
81 	if (next_busno > 224) {
82 		next_busno = 0;
83 		need_domain_info = 1;
84 	}
85 
86 	pci_bus_size_bridges(hose->bus);
87 	pci_bus_assign_resources(hose->bus);
88 	pci_bus_add_devices(hose->bus);
89 }
90 
91 /*
92  * This interrupt-safe spinlock protects all accesses to PCI
93  * configuration space.
94  */
95 DEFINE_RAW_SPINLOCK(pci_config_lock);
96 static DEFINE_MUTEX(pci_scan_mutex);
97 
98 int register_pci_controller(struct pci_channel *hose)
99 {
100 	int i;
101 
102 	for (i = 0; i < hose->nr_resources; i++) {
103 		struct resource *res = hose->resources + i;
104 
105 		if (res->flags & IORESOURCE_IO) {
106 			if (request_resource(&ioport_resource, res) < 0)
107 				goto out;
108 		} else {
109 			if (request_resource(&iomem_resource, res) < 0)
110 				goto out;
111 		}
112 	}
113 
114 	*hose_tail = hose;
115 	hose_tail = &hose->next;
116 
117 	/*
118 	 * Do not panic here but later - this might happen before console init.
119 	 */
120 	if (!hose->io_map_base) {
121 		printk(KERN_WARNING
122 		       "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 	printk(KERN_WARNING "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 	dma_debug_add_bus(&pci_bus_type);
159 
160 	pci_initialized = 1;
161 
162 	return 0;
163 }
164 subsys_initcall(pcibios_init);
165 
166 /*
167  * We need to avoid collisions with `mirrored' VGA ports
168  * and other strange ISA hardware, so we always want the
169  * addresses to be allocated in the 0x000-0x0ff region
170  * modulo 0x400.
171  */
172 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
173 				resource_size_t size, resource_size_t align)
174 {
175 	struct pci_dev *dev = data;
176 	struct pci_channel *hose = dev->sysdata;
177 	resource_size_t start = res->start;
178 
179 	if (res->flags & IORESOURCE_IO) {
180 		if (start < PCIBIOS_MIN_IO + hose->resources[0].start)
181 			start = PCIBIOS_MIN_IO + hose->resources[0].start;
182 
183 		/*
184                  * Put everything into 0x00-0xff region modulo 0x400.
185 		 */
186 		if (start & 0x300)
187 			start = (start + 0x3ff) & ~0x3ff;
188 	}
189 
190 	return start;
191 }
192 
193 static void __init
194 pcibios_bus_report_status_early(struct pci_channel *hose,
195 				int top_bus, int current_bus,
196 				unsigned int status_mask, int warn)
197 {
198 	unsigned int pci_devfn;
199 	u16 status;
200 	int ret;
201 
202 	for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
203 		if (PCI_FUNC(pci_devfn))
204 			continue;
205 		ret = early_read_config_word(hose, top_bus, current_bus,
206 					     pci_devfn, PCI_STATUS, &status);
207 		if (ret != PCIBIOS_SUCCESSFUL)
208 			continue;
209 		if (status == 0xffff)
210 			continue;
211 
212 		early_write_config_word(hose, top_bus, current_bus,
213 					pci_devfn, PCI_STATUS,
214 					status & status_mask);
215 		if (warn)
216 			printk("(%02x:%02x: %04X) ", current_bus,
217 			       pci_devfn, status);
218 	}
219 }
220 
221 /*
222  * We can't use pci_find_device() here since we are
223  * called from interrupt context.
224  */
225 static void __ref
226 pcibios_bus_report_status(struct pci_bus *bus, unsigned int status_mask,
227 			  int warn)
228 {
229 	struct pci_dev *dev;
230 
231 	list_for_each_entry(dev, &bus->devices, bus_list) {
232 		u16 status;
233 
234 		/*
235 		 * ignore host bridge - we handle
236 		 * that separately
237 		 */
238 		if (dev->bus->number == 0 && dev->devfn == 0)
239 			continue;
240 
241 		pci_read_config_word(dev, PCI_STATUS, &status);
242 		if (status == 0xffff)
243 			continue;
244 
245 		if ((status & status_mask) == 0)
246 			continue;
247 
248 		/* clear the status errors */
249 		pci_write_config_word(dev, PCI_STATUS, status & status_mask);
250 
251 		if (warn)
252 			printk("(%s: %04X) ", pci_name(dev), status);
253 	}
254 
255 	list_for_each_entry(dev, &bus->devices, bus_list)
256 		if (dev->subordinate)
257 			pcibios_bus_report_status(dev->subordinate, status_mask, warn);
258 }
259 
260 void __ref pcibios_report_status(unsigned int status_mask, int warn)
261 {
262 	struct pci_channel *hose;
263 
264 	for (hose = hose_head; hose; hose = hose->next) {
265 		if (unlikely(!hose->bus))
266 			pcibios_bus_report_status_early(hose, hose_head->index,
267 					hose->index, status_mask, warn);
268 		else
269 			pcibios_bus_report_status(hose->bus, status_mask, warn);
270 	}
271 }
272 
273 #ifndef CONFIG_GENERIC_IOMAP
274 
275 void __iomem *__pci_ioport_map(struct pci_dev *dev,
276 			       unsigned long port, unsigned int nr)
277 {
278 	struct pci_channel *chan = dev->sysdata;
279 
280 	if (unlikely(!chan->io_map_base)) {
281 		chan->io_map_base = sh_io_port_base;
282 
283 		if (pci_domains_supported)
284 			panic("To avoid data corruption io_map_base MUST be "
285 			      "set with multiple PCI domains.");
286 	}
287 
288 	return (void __iomem *)(chan->io_map_base + port);
289 }
290 
291 void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
292 {
293 	iounmap(addr);
294 }
295 EXPORT_SYMBOL(pci_iounmap);
296 
297 #endif /* CONFIG_GENERIC_IOMAP */
298 
299 EXPORT_SYMBOL(PCIBIOS_MIN_IO);
300 EXPORT_SYMBOL(PCIBIOS_MIN_MEM);
301