xref: /openbmc/linux/arch/sh/drivers/pci/pci.c (revision 1c2dd16a)
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;
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 
62 	if (!bus) {
63 		pci_free_resource_list(&resources);
64 		return;
65 	}
66 
67 	next_busno = bus->busn_res.end + 1;
68 	/* Don't allow 8-bit bus number overflow inside the hose -
69 	   reserve some space for bridges. */
70 	if (next_busno > 224) {
71 		next_busno = 0;
72 		need_domain_info = 1;
73 	}
74 
75 	pci_bus_size_bridges(bus);
76 	pci_bus_assign_resources(bus);
77 	pci_bus_add_devices(bus);
78 }
79 
80 /*
81  * This interrupt-safe spinlock protects all accesses to PCI
82  * configuration space.
83  */
84 DEFINE_RAW_SPINLOCK(pci_config_lock);
85 static DEFINE_MUTEX(pci_scan_mutex);
86 
87 int register_pci_controller(struct pci_channel *hose)
88 {
89 	int i;
90 
91 	for (i = 0; i < hose->nr_resources; i++) {
92 		struct resource *res = hose->resources + i;
93 
94 		if (res->flags & IORESOURCE_IO) {
95 			if (request_resource(&ioport_resource, res) < 0)
96 				goto out;
97 		} else {
98 			if (request_resource(&iomem_resource, res) < 0)
99 				goto out;
100 		}
101 	}
102 
103 	*hose_tail = hose;
104 	hose_tail = &hose->next;
105 
106 	/*
107 	 * Do not panic here but later - this might happen before console init.
108 	 */
109 	if (!hose->io_map_base) {
110 		printk(KERN_WARNING
111 		       "registering PCI controller with io_map_base unset\n");
112 	}
113 
114 	/*
115 	 * Setup the ERR/PERR and SERR timers, if available.
116 	 */
117 	pcibios_enable_timers(hose);
118 
119 	/*
120 	 * Scan the bus if it is register after the PCI subsystem
121 	 * initialization.
122 	 */
123 	if (pci_initialized) {
124 		mutex_lock(&pci_scan_mutex);
125 		pcibios_scanbus(hose);
126 		mutex_unlock(&pci_scan_mutex);
127 	}
128 
129 	return 0;
130 
131 out:
132 	for (--i; i >= 0; i--)
133 		release_resource(&hose->resources[i]);
134 
135 	printk(KERN_WARNING "Skipping PCI bus scan due to resource conflict\n");
136 	return -1;
137 }
138 
139 static int __init pcibios_init(void)
140 {
141 	struct pci_channel *hose;
142 
143 	/* Scan all of the recorded PCI controllers.  */
144 	for (hose = hose_head; hose; hose = hose->next)
145 		pcibios_scanbus(hose);
146 
147 	pci_fixup_irqs(pci_common_swizzle, pcibios_map_platform_irq);
148 
149 	dma_debug_add_bus(&pci_bus_type);
150 
151 	pci_initialized = 1;
152 
153 	return 0;
154 }
155 subsys_initcall(pcibios_init);
156 
157 /*
158  *  Called after each bus is probed, but before its children
159  *  are examined.
160  */
161 void pcibios_fixup_bus(struct pci_bus *bus)
162 {
163 }
164 
165 /*
166  * We need to avoid collisions with `mirrored' VGA ports
167  * and other strange ISA hardware, so we always want the
168  * addresses to be allocated in the 0x000-0x0ff region
169  * modulo 0x400.
170  */
171 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
172 				resource_size_t size, resource_size_t align)
173 {
174 	struct pci_dev *dev = data;
175 	struct pci_channel *hose = dev->sysdata;
176 	resource_size_t start = res->start;
177 
178 	if (res->flags & IORESOURCE_IO) {
179 		if (start < PCIBIOS_MIN_IO + hose->resources[0].start)
180 			start = PCIBIOS_MIN_IO + hose->resources[0].start;
181 
182 		/*
183                  * Put everything into 0x00-0xff region modulo 0x400.
184 		 */
185 		if (start & 0x300)
186 			start = (start + 0x3ff) & ~0x3ff;
187 	}
188 
189 	return start;
190 }
191 
192 static void __init
193 pcibios_bus_report_status_early(struct pci_channel *hose,
194 				int top_bus, int current_bus,
195 				unsigned int status_mask, int warn)
196 {
197 	unsigned int pci_devfn;
198 	u16 status;
199 	int ret;
200 
201 	for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
202 		if (PCI_FUNC(pci_devfn))
203 			continue;
204 		ret = early_read_config_word(hose, top_bus, current_bus,
205 					     pci_devfn, PCI_STATUS, &status);
206 		if (ret != PCIBIOS_SUCCESSFUL)
207 			continue;
208 		if (status == 0xffff)
209 			continue;
210 
211 		early_write_config_word(hose, top_bus, current_bus,
212 					pci_devfn, PCI_STATUS,
213 					status & status_mask);
214 		if (warn)
215 			printk("(%02x:%02x: %04X) ", current_bus,
216 			       pci_devfn, status);
217 	}
218 }
219 
220 /*
221  * We can't use pci_find_device() here since we are
222  * called from interrupt context.
223  */
224 static void __ref
225 pcibios_bus_report_status(struct pci_bus *bus, unsigned int status_mask,
226 			  int warn)
227 {
228 	struct pci_dev *dev;
229 
230 	list_for_each_entry(dev, &bus->devices, bus_list) {
231 		u16 status;
232 
233 		/*
234 		 * ignore host bridge - we handle
235 		 * that separately
236 		 */
237 		if (dev->bus->number == 0 && dev->devfn == 0)
238 			continue;
239 
240 		pci_read_config_word(dev, PCI_STATUS, &status);
241 		if (status == 0xffff)
242 			continue;
243 
244 		if ((status & status_mask) == 0)
245 			continue;
246 
247 		/* clear the status errors */
248 		pci_write_config_word(dev, PCI_STATUS, status & status_mask);
249 
250 		if (warn)
251 			printk("(%s: %04X) ", pci_name(dev), status);
252 	}
253 
254 	list_for_each_entry(dev, &bus->devices, bus_list)
255 		if (dev->subordinate)
256 			pcibios_bus_report_status(dev->subordinate, status_mask, warn);
257 }
258 
259 void __ref pcibios_report_status(unsigned int status_mask, int warn)
260 {
261 	struct pci_channel *hose;
262 
263 	for (hose = hose_head; hose; hose = hose->next) {
264 		if (unlikely(!hose->bus))
265 			pcibios_bus_report_status_early(hose, hose_head->index,
266 					hose->index, status_mask, warn);
267 		else
268 			pcibios_bus_report_status(hose->bus, status_mask, warn);
269 	}
270 }
271 
272 int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
273 			enum pci_mmap_state mmap_state, int write_combine)
274 {
275 	/*
276 	 * I/O space can be accessed via normal processor loads and stores on
277 	 * this platform but for now we elect not to do this and portable
278 	 * drivers should not do this anyway.
279 	 */
280 	if (mmap_state == pci_mmap_io)
281 		return -EINVAL;
282 
283 	/*
284 	 * Ignore write-combine; for now only return uncached mappings.
285 	 */
286 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
287 
288 	return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
289 			       vma->vm_end - vma->vm_start,
290 			       vma->vm_page_prot);
291 }
292 
293 #ifndef CONFIG_GENERIC_IOMAP
294 
295 void __iomem *__pci_ioport_map(struct pci_dev *dev,
296 			       unsigned long port, unsigned int nr)
297 {
298 	struct pci_channel *chan = dev->sysdata;
299 
300 	if (unlikely(!chan->io_map_base)) {
301 		chan->io_map_base = sh_io_port_base;
302 
303 		if (pci_domains_supported)
304 			panic("To avoid data corruption io_map_base MUST be "
305 			      "set with multiple PCI domains.");
306 	}
307 
308 	return (void __iomem *)(chan->io_map_base + port);
309 }
310 
311 void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
312 {
313 	iounmap(addr);
314 }
315 EXPORT_SYMBOL(pci_iounmap);
316 
317 #endif /* CONFIG_GENERIC_IOMAP */
318 
319 EXPORT_SYMBOL(PCIBIOS_MIN_IO);
320 EXPORT_SYMBOL(PCIBIOS_MIN_MEM);
321