xref: /linux/arch/mips/pci/pci.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
1 /*
2  * This program is free software; you can redistribute	it and/or modify it
3  * under  the terms of	the GNU General	 Public License as published by the
4  * Free Software Foundation;  either version 2 of the  License, or (at your
5  * option) any later version.
6  *
7  * Copyright (C) 2003, 04, 11 Ralf Baechle (ralf@linux-mips.org)
8  * Copyright (C) 2011 Wind River Systems,
9  *   written by Ralf Baechle (ralf@linux-mips.org)
10  */
11 #include <linux/bug.h>
12 #include <linux/kernel.h>
13 #include <linux/mm.h>
14 #include <linux/bootmem.h>
15 #include <linux/export.h>
16 #include <linux/init.h>
17 #include <linux/types.h>
18 #include <linux/pci.h>
19 #include <linux/of_address.h>
20 
21 #include <asm/cpu-info.h>
22 
23 /*
24  * If PCI_PROBE_ONLY in pci_flags is set, we don't change any PCI resource
25  * assignments.
26  */
27 
28 /*
29  * The PCI controller list.
30  */
31 
32 static struct pci_controller *hose_head, **hose_tail = &hose_head;
33 
34 unsigned long PCIBIOS_MIN_IO;
35 unsigned long PCIBIOS_MIN_MEM;
36 
37 static int pci_initialized;
38 
39 /*
40  * We need to avoid collisions with `mirrored' VGA ports
41  * and other strange ISA hardware, so we always want the
42  * addresses to be allocated in the 0x000-0x0ff region
43  * modulo 0x400.
44  *
45  * Why? Because some silly external IO cards only decode
46  * the low 10 bits of the IO address. The 0x00-0xff region
47  * is reserved for motherboard devices that decode all 16
48  * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
49  * but we want to try to avoid allocating at 0x2900-0x2bff
50  * which might have be mirrored at 0x0100-0x03ff..
51  */
52 resource_size_t
53 pcibios_align_resource(void *data, const struct resource *res,
54 		       resource_size_t size, resource_size_t align)
55 {
56 	struct pci_dev *dev = data;
57 	struct pci_controller *hose = dev->sysdata;
58 	resource_size_t start = res->start;
59 
60 	if (res->flags & IORESOURCE_IO) {
61 		/* Make sure we start at our min on all hoses */
62 		if (start < PCIBIOS_MIN_IO + hose->io_resource->start)
63 			start = PCIBIOS_MIN_IO + hose->io_resource->start;
64 
65 		/*
66 		 * Put everything into 0x00-0xff region modulo 0x400
67 		 */
68 		if (start & 0x300)
69 			start = (start + 0x3ff) & ~0x3ff;
70 	} else if (res->flags & IORESOURCE_MEM) {
71 		/* Make sure we start at our min on all hoses */
72 		if (start < PCIBIOS_MIN_MEM + hose->mem_resource->start)
73 			start = PCIBIOS_MIN_MEM + hose->mem_resource->start;
74 	}
75 
76 	return start;
77 }
78 
79 static void pcibios_scanbus(struct pci_controller *hose)
80 {
81 	static int next_busno;
82 	static int need_domain_info;
83 	LIST_HEAD(resources);
84 	struct pci_bus *bus;
85 
86 	if (hose->get_busno && pci_has_flag(PCI_PROBE_ONLY))
87 		next_busno = (*hose->get_busno)();
88 
89 	pci_add_resource_offset(&resources,
90 				hose->mem_resource, hose->mem_offset);
91 	pci_add_resource_offset(&resources,
92 				hose->io_resource, hose->io_offset);
93 	pci_add_resource_offset(&resources,
94 				hose->busn_resource, hose->busn_offset);
95 	bus = pci_scan_root_bus(NULL, next_busno, hose->pci_ops, hose,
96 				&resources);
97 	hose->bus = bus;
98 
99 	need_domain_info = need_domain_info || hose->index;
100 	hose->need_domain_info = need_domain_info;
101 
102 	if (!bus) {
103 		pci_free_resource_list(&resources);
104 		return;
105 	}
106 
107 	next_busno = bus->busn_res.end + 1;
108 	/* Don't allow 8-bit bus number overflow inside the hose -
109 	   reserve some space for bridges. */
110 	if (next_busno > 224) {
111 		next_busno = 0;
112 		need_domain_info = 1;
113 	}
114 
115 	/*
116 	 * We insert PCI resources into the iomem_resource and
117 	 * ioport_resource trees in either pci_bus_claim_resources()
118 	 * or pci_bus_assign_resources().
119 	 */
120 	if (pci_has_flag(PCI_PROBE_ONLY)) {
121 		pci_bus_claim_resources(bus);
122 	} else {
123 		pci_bus_size_bridges(bus);
124 		pci_bus_assign_resources(bus);
125 	}
126 	pci_bus_add_devices(bus);
127 }
128 
129 #ifdef CONFIG_OF
130 void pci_load_of_ranges(struct pci_controller *hose, struct device_node *node)
131 {
132 	struct of_pci_range range;
133 	struct of_pci_range_parser parser;
134 
135 	pr_info("PCI host bridge %s ranges:\n", node->full_name);
136 	hose->of_node = node;
137 
138 	if (of_pci_range_parser_init(&parser, node))
139 		return;
140 
141 	for_each_of_pci_range(&parser, &range) {
142 		struct resource *res = NULL;
143 
144 		switch (range.flags & IORESOURCE_TYPE_BITS) {
145 		case IORESOURCE_IO:
146 			pr_info("  IO 0x%016llx..0x%016llx\n",
147 				range.cpu_addr,
148 				range.cpu_addr + range.size - 1);
149 			hose->io_map_base =
150 				(unsigned long)ioremap(range.cpu_addr,
151 						       range.size);
152 			res = hose->io_resource;
153 			break;
154 		case IORESOURCE_MEM:
155 			pr_info(" MEM 0x%016llx..0x%016llx\n",
156 				range.cpu_addr,
157 				range.cpu_addr + range.size - 1);
158 			res = hose->mem_resource;
159 			break;
160 		}
161 		if (res != NULL)
162 			of_pci_range_to_resource(&range, node, res);
163 	}
164 }
165 
166 struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus)
167 {
168 	struct pci_controller *hose = bus->sysdata;
169 
170 	return of_node_get(hose->of_node);
171 }
172 #endif
173 
174 static DEFINE_MUTEX(pci_scan_mutex);
175 
176 void register_pci_controller(struct pci_controller *hose)
177 {
178 	struct resource *parent;
179 
180 	parent = hose->mem_resource->parent;
181 	if (!parent)
182 		parent = &iomem_resource;
183 
184 	if (request_resource(parent, hose->mem_resource) < 0)
185 		goto out;
186 
187 	parent = hose->io_resource->parent;
188 	if (!parent)
189 		parent = &ioport_resource;
190 
191 	if (request_resource(parent, hose->io_resource) < 0) {
192 		release_resource(hose->mem_resource);
193 		goto out;
194 	}
195 
196 	*hose_tail = hose;
197 	hose_tail = &hose->next;
198 
199 	/*
200 	 * Do not panic here but later - this might happen before console init.
201 	 */
202 	if (!hose->io_map_base) {
203 		printk(KERN_WARNING
204 		       "registering PCI controller with io_map_base unset\n");
205 	}
206 
207 	/*
208 	 * Scan the bus if it is register after the PCI subsystem
209 	 * initialization.
210 	 */
211 	if (pci_initialized) {
212 		mutex_lock(&pci_scan_mutex);
213 		pcibios_scanbus(hose);
214 		mutex_unlock(&pci_scan_mutex);
215 	}
216 
217 	return;
218 
219 out:
220 	printk(KERN_WARNING
221 	       "Skipping PCI bus scan due to resource conflict\n");
222 }
223 
224 static void __init pcibios_set_cache_line_size(void)
225 {
226 	struct cpuinfo_mips *c = &current_cpu_data;
227 	unsigned int lsize;
228 
229 	/*
230 	 * Set PCI cacheline size to that of the highest level in the
231 	 * cache hierarchy.
232 	 */
233 	lsize = c->dcache.linesz;
234 	lsize = c->scache.linesz ? : lsize;
235 	lsize = c->tcache.linesz ? : lsize;
236 
237 	BUG_ON(!lsize);
238 
239 	pci_dfl_cache_line_size = lsize >> 2;
240 
241 	pr_debug("PCI: pci_cache_line_size set to %d bytes\n", lsize);
242 }
243 
244 static int __init pcibios_init(void)
245 {
246 	struct pci_controller *hose;
247 
248 	pcibios_set_cache_line_size();
249 
250 	/* Scan all of the recorded PCI controllers.  */
251 	for (hose = hose_head; hose; hose = hose->next)
252 		pcibios_scanbus(hose);
253 
254 	pci_fixup_irqs(pci_common_swizzle, pcibios_map_irq);
255 
256 	pci_initialized = 1;
257 
258 	return 0;
259 }
260 
261 subsys_initcall(pcibios_init);
262 
263 static int pcibios_enable_resources(struct pci_dev *dev, int mask)
264 {
265 	u16 cmd, old_cmd;
266 	int idx;
267 	struct resource *r;
268 
269 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
270 	old_cmd = cmd;
271 	for (idx=0; idx < PCI_NUM_RESOURCES; idx++) {
272 		/* Only set up the requested stuff */
273 		if (!(mask & (1<<idx)))
274 			continue;
275 
276 		r = &dev->resource[idx];
277 		if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
278 			continue;
279 		if ((idx == PCI_ROM_RESOURCE) &&
280 				(!(r->flags & IORESOURCE_ROM_ENABLE)))
281 			continue;
282 		if (!r->start && r->end) {
283 			printk(KERN_ERR "PCI: Device %s not available "
284 			       "because of resource collisions\n",
285 			       pci_name(dev));
286 			return -EINVAL;
287 		}
288 		if (r->flags & IORESOURCE_IO)
289 			cmd |= PCI_COMMAND_IO;
290 		if (r->flags & IORESOURCE_MEM)
291 			cmd |= PCI_COMMAND_MEMORY;
292 	}
293 	if (cmd != old_cmd) {
294 		printk("PCI: Enabling device %s (%04x -> %04x)\n",
295 		       pci_name(dev), old_cmd, cmd);
296 		pci_write_config_word(dev, PCI_COMMAND, cmd);
297 	}
298 	return 0;
299 }
300 
301 unsigned int pcibios_assign_all_busses(void)
302 {
303 	return 1;
304 }
305 
306 int pcibios_enable_device(struct pci_dev *dev, int mask)
307 {
308 	int err;
309 
310 	if ((err = pcibios_enable_resources(dev, mask)) < 0)
311 		return err;
312 
313 	return pcibios_plat_dev_init(dev);
314 }
315 
316 void pcibios_fixup_bus(struct pci_bus *bus)
317 {
318 	struct pci_dev *dev = bus->self;
319 
320 	if (pci_has_flag(PCI_PROBE_ONLY) && dev &&
321 	    (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
322 		pci_read_bridge_bases(bus);
323 	}
324 }
325 
326 EXPORT_SYMBOL(PCIBIOS_MIN_IO);
327 EXPORT_SYMBOL(PCIBIOS_MIN_MEM);
328 
329 void pci_resource_to_user(const struct pci_dev *dev, int bar,
330 			  const struct resource *rsrc, resource_size_t *start,
331 			  resource_size_t *end)
332 {
333 	phys_addr_t size = resource_size(rsrc);
334 
335 	*start = fixup_bigphys_addr(rsrc->start, size);
336 	*end = rsrc->start + size;
337 }
338 
339 int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
340 			enum pci_mmap_state mmap_state, int write_combine)
341 {
342 	unsigned long prot;
343 
344 	/*
345 	 * I/O space can be accessed via normal processor loads and stores on
346 	 * this platform but for now we elect not to do this and portable
347 	 * drivers should not do this anyway.
348 	 */
349 	if (mmap_state == pci_mmap_io)
350 		return -EINVAL;
351 
352 	/*
353 	 * Ignore write-combine; for now only return uncached mappings.
354 	 */
355 	prot = pgprot_val(vma->vm_page_prot);
356 	prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED;
357 	vma->vm_page_prot = __pgprot(prot);
358 
359 	return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
360 		vma->vm_end - vma->vm_start, vma->vm_page_prot);
361 }
362 
363 char * (*pcibios_plat_setup)(char *str) __initdata;
364 
365 char *__init pcibios_setup(char *str)
366 {
367 	if (pcibios_plat_setup)
368 		return pcibios_plat_setup(str);
369 	return str;
370 }
371