xref: /linux/arch/mips/pci/pci.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 __devinit 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->iommu)
87 		PCI_DMA_BUS_IS_PHYS = 1;
88 
89 	if (hose->get_busno && pci_has_flag(PCI_PROBE_ONLY))
90 		next_busno = (*hose->get_busno)();
91 
92 	pci_add_resource_offset(&resources,
93 				hose->mem_resource, hose->mem_offset);
94 	pci_add_resource_offset(&resources, hose->io_resource, hose->io_offset);
95 	bus = pci_scan_root_bus(NULL, next_busno, hose->pci_ops, hose,
96 				&resources);
97 	if (!bus)
98 		pci_free_resource_list(&resources);
99 
100 	hose->bus = bus;
101 
102 	need_domain_info = need_domain_info || hose->index;
103 	hose->need_domain_info = need_domain_info;
104 	if (bus) {
105 		next_busno = bus->busn_res.end + 1;
106 		/* Don't allow 8-bit bus number overflow inside the hose -
107 		   reserve some space for bridges. */
108 		if (next_busno > 224) {
109 			next_busno = 0;
110 			need_domain_info = 1;
111 		}
112 
113 		if (!pci_has_flag(PCI_PROBE_ONLY)) {
114 			pci_bus_size_bridges(bus);
115 			pci_bus_assign_resources(bus);
116 			pci_enable_bridges(bus);
117 		}
118 		bus->dev.of_node = hose->of_node;
119 	}
120 }
121 
122 #ifdef CONFIG_OF
123 void __devinit pci_load_of_ranges(struct pci_controller *hose,
124 				struct device_node *node)
125 {
126 	const __be32 *ranges;
127 	int rlen;
128 	int pna = of_n_addr_cells(node);
129 	int np = pna + 5;
130 
131 	pr_info("PCI host bridge %s ranges:\n", node->full_name);
132 	ranges = of_get_property(node, "ranges", &rlen);
133 	if (ranges == NULL)
134 		return;
135 	hose->of_node = node;
136 
137 	while ((rlen -= np * 4) >= 0) {
138 		u32 pci_space;
139 		struct resource *res = NULL;
140 		u64 addr, size;
141 
142 		pci_space = be32_to_cpup(&ranges[0]);
143 		addr = of_translate_address(node, ranges + 3);
144 		size = of_read_number(ranges + pna + 3, 2);
145 		ranges += np;
146 		switch ((pci_space >> 24) & 0x3) {
147 		case 1:		/* PCI IO space */
148 			pr_info("  IO 0x%016llx..0x%016llx\n",
149 					addr, addr + size - 1);
150 			hose->io_map_base =
151 				(unsigned long)ioremap(addr, size);
152 			res = hose->io_resource;
153 			res->flags = IORESOURCE_IO;
154 			break;
155 		case 2:		/* PCI Memory space */
156 		case 3:		/* PCI 64 bits Memory space */
157 			pr_info(" MEM 0x%016llx..0x%016llx\n",
158 					addr, addr + size - 1);
159 			res = hose->mem_resource;
160 			res->flags = IORESOURCE_MEM;
161 			break;
162 		}
163 		if (res != NULL) {
164 			res->start = addr;
165 			res->name = node->full_name;
166 			res->end = res->start + size - 1;
167 			res->parent = NULL;
168 			res->sibling = NULL;
169 			res->child = NULL;
170 		}
171 	}
172 }
173 #endif
174 
175 static DEFINE_MUTEX(pci_scan_mutex);
176 
177 void __devinit register_pci_controller(struct pci_controller *hose)
178 {
179 	if (request_resource(&iomem_resource, hose->mem_resource) < 0)
180 		goto out;
181 	if (request_resource(&ioport_resource, hose->io_resource) < 0) {
182 		release_resource(hose->mem_resource);
183 		goto out;
184 	}
185 
186 	*hose_tail = hose;
187 	hose_tail = &hose->next;
188 
189 	/*
190 	 * Do not panic here but later - this might happen before console init.
191 	 */
192 	if (!hose->io_map_base) {
193 		printk(KERN_WARNING
194 		       "registering PCI controller with io_map_base unset\n");
195 	}
196 
197 	/*
198 	 * Scan the bus if it is register after the PCI subsystem
199 	 * initialization.
200 	 */
201 	if (pci_initialized) {
202 		mutex_lock(&pci_scan_mutex);
203 		pcibios_scanbus(hose);
204 		mutex_unlock(&pci_scan_mutex);
205 	}
206 
207 	return;
208 
209 out:
210 	printk(KERN_WARNING
211 	       "Skipping PCI bus scan due to resource conflict\n");
212 }
213 
214 static void __init pcibios_set_cache_line_size(void)
215 {
216 	struct cpuinfo_mips *c = &current_cpu_data;
217 	unsigned int lsize;
218 
219 	/*
220 	 * Set PCI cacheline size to that of the highest level in the
221 	 * cache hierarchy.
222 	 */
223 	lsize = c->dcache.linesz;
224 	lsize = c->scache.linesz ? : lsize;
225 	lsize = c->tcache.linesz ? : lsize;
226 
227 	BUG_ON(!lsize);
228 
229 	pci_dfl_cache_line_size = lsize >> 2;
230 
231 	pr_debug("PCI: pci_cache_line_size set to %d bytes\n", lsize);
232 }
233 
234 static int __init pcibios_init(void)
235 {
236 	struct pci_controller *hose;
237 
238 	pcibios_set_cache_line_size();
239 
240 	/* Scan all of the recorded PCI controllers.  */
241 	for (hose = hose_head; hose; hose = hose->next)
242 		pcibios_scanbus(hose);
243 
244 	pci_fixup_irqs(pci_common_swizzle, pcibios_map_irq);
245 
246 	pci_initialized = 1;
247 
248 	return 0;
249 }
250 
251 subsys_initcall(pcibios_init);
252 
253 static int pcibios_enable_resources(struct pci_dev *dev, int mask)
254 {
255 	u16 cmd, old_cmd;
256 	int idx;
257 	struct resource *r;
258 
259 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
260 	old_cmd = cmd;
261 	for (idx=0; idx < PCI_NUM_RESOURCES; idx++) {
262 		/* Only set up the requested stuff */
263 		if (!(mask & (1<<idx)))
264 			continue;
265 
266 		r = &dev->resource[idx];
267 		if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
268 			continue;
269 		if ((idx == PCI_ROM_RESOURCE) &&
270 				(!(r->flags & IORESOURCE_ROM_ENABLE)))
271 			continue;
272 		if (!r->start && r->end) {
273 			printk(KERN_ERR "PCI: Device %s not available "
274 			       "because of resource collisions\n",
275 			       pci_name(dev));
276 			return -EINVAL;
277 		}
278 		if (r->flags & IORESOURCE_IO)
279 			cmd |= PCI_COMMAND_IO;
280 		if (r->flags & IORESOURCE_MEM)
281 			cmd |= PCI_COMMAND_MEMORY;
282 	}
283 	if (cmd != old_cmd) {
284 		printk("PCI: Enabling device %s (%04x -> %04x)\n",
285 		       pci_name(dev), old_cmd, cmd);
286 		pci_write_config_word(dev, PCI_COMMAND, cmd);
287 	}
288 	return 0;
289 }
290 
291 unsigned int pcibios_assign_all_busses(void)
292 {
293 	return 1;
294 }
295 
296 int pcibios_enable_device(struct pci_dev *dev, int mask)
297 {
298 	int err;
299 
300 	if ((err = pcibios_enable_resources(dev, mask)) < 0)
301 		return err;
302 
303 	return pcibios_plat_dev_init(dev);
304 }
305 
306 void __devinit pcibios_fixup_bus(struct pci_bus *bus)
307 {
308 	struct pci_dev *dev = bus->self;
309 
310 	if (pci_has_flag(PCI_PROBE_ONLY) && dev &&
311 	    (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
312 		pci_read_bridge_bases(bus);
313 	}
314 }
315 
316 EXPORT_SYMBOL(PCIBIOS_MIN_IO);
317 EXPORT_SYMBOL(PCIBIOS_MIN_MEM);
318 
319 int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
320 			enum pci_mmap_state mmap_state, int write_combine)
321 {
322 	unsigned long prot;
323 
324 	/*
325 	 * I/O space can be accessed via normal processor loads and stores on
326 	 * this platform but for now we elect not to do this and portable
327 	 * drivers should not do this anyway.
328 	 */
329 	if (mmap_state == pci_mmap_io)
330 		return -EINVAL;
331 
332 	/*
333 	 * Ignore write-combine; for now only return uncached mappings.
334 	 */
335 	prot = pgprot_val(vma->vm_page_prot);
336 	prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED;
337 	vma->vm_page_prot = __pgprot(prot);
338 
339 	return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
340 		vma->vm_end - vma->vm_start, vma->vm_page_prot);
341 }
342 
343 char * (*pcibios_plat_setup)(char *str) __initdata;
344 
345 char *__init pcibios_setup(char *str)
346 {
347 	if (pcibios_plat_setup)
348 		return pcibios_plat_setup(str);
349 	return str;
350 }
351