xref: /openbmc/linux/arch/sh/drivers/pci/pci.c (revision 95e9fd10)
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 __devinit 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;
43 	struct pci_bus *bus;
44 
45 	for (i = 0; i < hose->nr_resources; i++) {
46 		res = hose->resources + i;
47 		offset = 0;
48 		if (res->flags & IORESOURCE_IO)
49 			offset = hose->io_offset;
50 		else if (res->flags & IORESOURCE_MEM)
51 			offset = hose->mem_offset;
52 		pci_add_resource_offset(&resources, res, offset);
53 	}
54 
55 	bus = pci_scan_root_bus(NULL, next_busno, hose->pci_ops, hose,
56 				&resources);
57 	hose->bus = bus;
58 
59 	need_domain_info = need_domain_info || hose->index;
60 	hose->need_domain_info = need_domain_info;
61 	if (bus) {
62 		next_busno = bus->busn_res.end + 1;
63 		/* Don't allow 8-bit bus number overflow inside the hose -
64 		   reserve some space for bridges. */
65 		if (next_busno > 224) {
66 			next_busno = 0;
67 			need_domain_info = 1;
68 		}
69 
70 		pci_bus_size_bridges(bus);
71 		pci_bus_assign_resources(bus);
72 		pci_enable_bridges(bus);
73 	} else {
74 		pci_free_resource_list(&resources);
75 	}
76 }
77 
78 /*
79  * This interrupt-safe spinlock protects all accesses to PCI
80  * configuration space.
81  */
82 DEFINE_RAW_SPINLOCK(pci_config_lock);
83 static DEFINE_MUTEX(pci_scan_mutex);
84 
85 int __devinit register_pci_controller(struct pci_channel *hose)
86 {
87 	int i;
88 
89 	for (i = 0; i < hose->nr_resources; i++) {
90 		struct resource *res = hose->resources + i;
91 
92 		if (res->flags & IORESOURCE_IO) {
93 			if (request_resource(&ioport_resource, res) < 0)
94 				goto out;
95 		} else {
96 			if (request_resource(&iomem_resource, res) < 0)
97 				goto out;
98 		}
99 	}
100 
101 	*hose_tail = hose;
102 	hose_tail = &hose->next;
103 
104 	/*
105 	 * Do not panic here but later - this might happen before console init.
106 	 */
107 	if (!hose->io_map_base) {
108 		printk(KERN_WARNING
109 		       "registering PCI controller with io_map_base unset\n");
110 	}
111 
112 	/*
113 	 * Setup the ERR/PERR and SERR timers, if available.
114 	 */
115 	pcibios_enable_timers(hose);
116 
117 	/*
118 	 * Scan the bus if it is register after the PCI subsystem
119 	 * initialization.
120 	 */
121 	if (pci_initialized) {
122 		mutex_lock(&pci_scan_mutex);
123 		pcibios_scanbus(hose);
124 		mutex_unlock(&pci_scan_mutex);
125 	}
126 
127 	return 0;
128 
129 out:
130 	for (--i; i >= 0; i--)
131 		release_resource(&hose->resources[i]);
132 
133 	printk(KERN_WARNING "Skipping PCI bus scan due to resource conflict\n");
134 	return -1;
135 }
136 
137 static int __init pcibios_init(void)
138 {
139 	struct pci_channel *hose;
140 
141 	/* Scan all of the recorded PCI controllers.  */
142 	for (hose = hose_head; hose; hose = hose->next)
143 		pcibios_scanbus(hose);
144 
145 	pci_fixup_irqs(pci_common_swizzle, pcibios_map_platform_irq);
146 
147 	dma_debug_add_bus(&pci_bus_type);
148 
149 	pci_initialized = 1;
150 
151 	return 0;
152 }
153 subsys_initcall(pcibios_init);
154 
155 /*
156  *  Called after each bus is probed, but before its children
157  *  are examined.
158  */
159 void __devinit pcibios_fixup_bus(struct pci_bus *bus)
160 {
161 }
162 
163 /*
164  * We need to avoid collisions with `mirrored' VGA ports
165  * and other strange ISA hardware, so we always want the
166  * addresses to be allocated in the 0x000-0x0ff region
167  * modulo 0x400.
168  */
169 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
170 				resource_size_t size, resource_size_t align)
171 {
172 	struct pci_dev *dev = data;
173 	struct pci_channel *hose = dev->sysdata;
174 	resource_size_t start = res->start;
175 
176 	if (res->flags & IORESOURCE_IO) {
177 		if (start < PCIBIOS_MIN_IO + hose->resources[0].start)
178 			start = PCIBIOS_MIN_IO + hose->resources[0].start;
179 
180 		/*
181                  * Put everything into 0x00-0xff region modulo 0x400.
182 		 */
183 		if (start & 0x300)
184 			start = (start + 0x3ff) & ~0x3ff;
185 	}
186 
187 	return start;
188 }
189 
190 int pcibios_enable_device(struct pci_dev *dev, int mask)
191 {
192 	return pci_enable_resources(dev, mask);
193 }
194 
195 void __init pcibios_update_irq(struct pci_dev *dev, int irq)
196 {
197 	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
198 }
199 
200 static void __init
201 pcibios_bus_report_status_early(struct pci_channel *hose,
202 				int top_bus, int current_bus,
203 				unsigned int status_mask, int warn)
204 {
205 	unsigned int pci_devfn;
206 	u16 status;
207 	int ret;
208 
209 	for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
210 		if (PCI_FUNC(pci_devfn))
211 			continue;
212 		ret = early_read_config_word(hose, top_bus, current_bus,
213 					     pci_devfn, PCI_STATUS, &status);
214 		if (ret != PCIBIOS_SUCCESSFUL)
215 			continue;
216 		if (status == 0xffff)
217 			continue;
218 
219 		early_write_config_word(hose, top_bus, current_bus,
220 					pci_devfn, PCI_STATUS,
221 					status & status_mask);
222 		if (warn)
223 			printk("(%02x:%02x: %04X) ", current_bus,
224 			       pci_devfn, status);
225 	}
226 }
227 
228 /*
229  * We can't use pci_find_device() here since we are
230  * called from interrupt context.
231  */
232 static void __init_refok
233 pcibios_bus_report_status(struct pci_bus *bus, unsigned int status_mask,
234 			  int warn)
235 {
236 	struct pci_dev *dev;
237 
238 	list_for_each_entry(dev, &bus->devices, bus_list) {
239 		u16 status;
240 
241 		/*
242 		 * ignore host bridge - we handle
243 		 * that separately
244 		 */
245 		if (dev->bus->number == 0 && dev->devfn == 0)
246 			continue;
247 
248 		pci_read_config_word(dev, PCI_STATUS, &status);
249 		if (status == 0xffff)
250 			continue;
251 
252 		if ((status & status_mask) == 0)
253 			continue;
254 
255 		/* clear the status errors */
256 		pci_write_config_word(dev, PCI_STATUS, status & status_mask);
257 
258 		if (warn)
259 			printk("(%s: %04X) ", pci_name(dev), status);
260 	}
261 
262 	list_for_each_entry(dev, &bus->devices, bus_list)
263 		if (dev->subordinate)
264 			pcibios_bus_report_status(dev->subordinate, status_mask, warn);
265 }
266 
267 void __init_refok pcibios_report_status(unsigned int status_mask, int warn)
268 {
269 	struct pci_channel *hose;
270 
271 	for (hose = hose_head; hose; hose = hose->next) {
272 		if (unlikely(!hose->bus))
273 			pcibios_bus_report_status_early(hose, hose_head->index,
274 					hose->index, status_mask, warn);
275 		else
276 			pcibios_bus_report_status(hose->bus, status_mask, warn);
277 	}
278 }
279 
280 int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
281 			enum pci_mmap_state mmap_state, int write_combine)
282 {
283 	/*
284 	 * I/O space can be accessed via normal processor loads and stores on
285 	 * this platform but for now we elect not to do this and portable
286 	 * drivers should not do this anyway.
287 	 */
288 	if (mmap_state == pci_mmap_io)
289 		return -EINVAL;
290 
291 	/*
292 	 * Ignore write-combine; for now only return uncached mappings.
293 	 */
294 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
295 
296 	return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
297 			       vma->vm_end - vma->vm_start,
298 			       vma->vm_page_prot);
299 }
300 
301 #ifndef CONFIG_GENERIC_IOMAP
302 
303 void __iomem *__pci_ioport_map(struct pci_dev *dev,
304 			       unsigned long port, unsigned int nr)
305 {
306 	struct pci_channel *chan = dev->sysdata;
307 
308 	if (unlikely(!chan->io_map_base)) {
309 		chan->io_map_base = sh_io_port_base;
310 
311 		if (pci_domains_supported)
312 			panic("To avoid data corruption io_map_base MUST be "
313 			      "set with multiple PCI domains.");
314 	}
315 
316 	return (void __iomem *)(chan->io_map_base + port);
317 }
318 
319 void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
320 {
321 	iounmap(addr);
322 }
323 EXPORT_SYMBOL(pci_iounmap);
324 
325 #endif /* CONFIG_GENERIC_IOMAP */
326 
327 #ifdef CONFIG_HOTPLUG
328 EXPORT_SYMBOL(PCIBIOS_MIN_IO);
329 EXPORT_SYMBOL(PCIBIOS_MIN_MEM);
330 #endif
331