xref: /openbmc/linux/drivers/pci/setup-res.c (revision 63dc02bd)
1 /*
2  *	drivers/pci/setup-res.c
3  *
4  * Extruded from code written by
5  *      Dave Rusling (david.rusling@reo.mts.dec.com)
6  *      David Mosberger (davidm@cs.arizona.edu)
7  *	David Miller (davem@redhat.com)
8  *
9  * Support routines for initializing a PCI subsystem.
10  */
11 
12 /* fixed for multiple pci buses, 1999 Andrea Arcangeli <andrea@suse.de> */
13 
14 /*
15  * Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
16  *	     Resource sorting
17  */
18 
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/export.h>
22 #include <linux/pci.h>
23 #include <linux/errno.h>
24 #include <linux/ioport.h>
25 #include <linux/cache.h>
26 #include <linux/slab.h>
27 #include "pci.h"
28 
29 
30 void pci_update_resource(struct pci_dev *dev, int resno)
31 {
32 	struct pci_bus_region region;
33 	u32 new, check, mask;
34 	int reg;
35 	enum pci_bar_type type;
36 	struct resource *res = dev->resource + resno;
37 
38 	/*
39 	 * Ignore resources for unimplemented BARs and unused resource slots
40 	 * for 64 bit BARs.
41 	 */
42 	if (!res->flags)
43 		return;
44 
45 	/*
46 	 * Ignore non-moveable resources.  This might be legacy resources for
47 	 * which no functional BAR register exists or another important
48 	 * system resource we shouldn't move around.
49 	 */
50 	if (res->flags & IORESOURCE_PCI_FIXED)
51 		return;
52 
53 	pcibios_resource_to_bus(dev, &region, res);
54 
55 	new = region.start | (res->flags & PCI_REGION_FLAG_MASK);
56 	if (res->flags & IORESOURCE_IO)
57 		mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
58 	else
59 		mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
60 
61 	reg = pci_resource_bar(dev, resno, &type);
62 	if (!reg)
63 		return;
64 	if (type != pci_bar_unknown) {
65 		if (!(res->flags & IORESOURCE_ROM_ENABLE))
66 			return;
67 		new |= PCI_ROM_ADDRESS_ENABLE;
68 	}
69 
70 	pci_write_config_dword(dev, reg, new);
71 	pci_read_config_dword(dev, reg, &check);
72 
73 	if ((new ^ check) & mask) {
74 		dev_err(&dev->dev, "BAR %d: error updating (%#08x != %#08x)\n",
75 			resno, new, check);
76 	}
77 
78 	if (res->flags & IORESOURCE_MEM_64) {
79 		new = region.start >> 16 >> 16;
80 		pci_write_config_dword(dev, reg + 4, new);
81 		pci_read_config_dword(dev, reg + 4, &check);
82 		if (check != new) {
83 			dev_err(&dev->dev, "BAR %d: error updating "
84 			       "(high %#08x != %#08x)\n", resno, new, check);
85 		}
86 	}
87 	res->flags &= ~IORESOURCE_UNSET;
88 	dev_dbg(&dev->dev, "BAR %d: set to %pR (PCI address [%#llx-%#llx])\n",
89 		resno, res, (unsigned long long)region.start,
90 		(unsigned long long)region.end);
91 }
92 
93 int pci_claim_resource(struct pci_dev *dev, int resource)
94 {
95 	struct resource *res = &dev->resource[resource];
96 	struct resource *root, *conflict;
97 
98 	root = pci_find_parent_resource(dev, res);
99 	if (!root) {
100 		dev_info(&dev->dev, "no compatible bridge window for %pR\n",
101 			 res);
102 		return -EINVAL;
103 	}
104 
105 	conflict = request_resource_conflict(root, res);
106 	if (conflict) {
107 		dev_info(&dev->dev,
108 			 "address space collision: %pR conflicts with %s %pR\n",
109 			 res, conflict->name, conflict);
110 		return -EBUSY;
111 	}
112 
113 	return 0;
114 }
115 EXPORT_SYMBOL(pci_claim_resource);
116 
117 void pci_disable_bridge_window(struct pci_dev *dev)
118 {
119 	dev_info(&dev->dev, "disabling bridge mem windows\n");
120 
121 	/* MMIO Base/Limit */
122 	pci_write_config_dword(dev, PCI_MEMORY_BASE, 0x0000fff0);
123 
124 	/* Prefetchable MMIO Base/Limit */
125 	pci_write_config_dword(dev, PCI_PREF_LIMIT_UPPER32, 0);
126 	pci_write_config_dword(dev, PCI_PREF_MEMORY_BASE, 0x0000fff0);
127 	pci_write_config_dword(dev, PCI_PREF_BASE_UPPER32, 0xffffffff);
128 }
129 
130 static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
131 		int resno, resource_size_t size, resource_size_t align)
132 {
133 	struct resource *res = dev->resource + resno;
134 	resource_size_t min;
135 	int ret;
136 
137 	min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
138 
139 	/* First, try exact prefetching match.. */
140 	ret = pci_bus_alloc_resource(bus, res, size, align, min,
141 				     IORESOURCE_PREFETCH,
142 				     pcibios_align_resource, dev);
143 
144 	if (ret < 0 && (res->flags & IORESOURCE_PREFETCH)) {
145 		/*
146 		 * That failed.
147 		 *
148 		 * But a prefetching area can handle a non-prefetching
149 		 * window (it will just not perform as well).
150 		 */
151 		ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
152 					     pcibios_align_resource, dev);
153 	}
154 	return ret;
155 }
156 
157 /*
158  * Generic function that returns a value indicating that the device's
159  * original BIOS BAR address was not saved and so is not available for
160  * reinstatement.
161  *
162  * Can be over-ridden by architecture specific code that implements
163  * reinstatement functionality rather than leaving it disabled when
164  * normal allocation attempts fail.
165  */
166 resource_size_t __weak pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx)
167 {
168 	return 0;
169 }
170 
171 static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
172 		int resno, resource_size_t size)
173 {
174 	struct resource *root, *conflict;
175 	resource_size_t fw_addr, start, end;
176 	int ret = 0;
177 
178 	fw_addr = pcibios_retrieve_fw_addr(dev, resno);
179 	if (!fw_addr)
180 		return 1;
181 
182 	start = res->start;
183 	end = res->end;
184 	res->start = fw_addr;
185 	res->end = res->start + size - 1;
186 
187 	root = pci_find_parent_resource(dev, res);
188 	if (!root) {
189 		if (res->flags & IORESOURCE_IO)
190 			root = &ioport_resource;
191 		else
192 			root = &iomem_resource;
193 	}
194 
195 	dev_info(&dev->dev, "BAR %d: trying firmware assignment %pR\n",
196 		 resno, res);
197 	conflict = request_resource_conflict(root, res);
198 	if (conflict) {
199 		dev_info(&dev->dev,
200 			 "BAR %d: %pR conflicts with %s %pR\n", resno,
201 			 res, conflict->name, conflict);
202 		res->start = start;
203 		res->end = end;
204 		ret = 1;
205 	}
206 	return ret;
207 }
208 
209 static int _pci_assign_resource(struct pci_dev *dev, int resno, int size, resource_size_t min_align)
210 {
211 	struct resource *res = dev->resource + resno;
212 	struct pci_bus *bus;
213 	int ret;
214 	char *type;
215 
216 	bus = dev->bus;
217 	while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
218 		if (!bus->parent || !bus->self->transparent)
219 			break;
220 		bus = bus->parent;
221 	}
222 
223 	if (ret) {
224 		if (res->flags & IORESOURCE_MEM)
225 			if (res->flags & IORESOURCE_PREFETCH)
226 				type = "mem pref";
227 			else
228 				type = "mem";
229 		else if (res->flags & IORESOURCE_IO)
230 			type = "io";
231 		else
232 			type = "unknown";
233 		dev_info(&dev->dev,
234 			 "BAR %d: can't assign %s (size %#llx)\n",
235 			 resno, type, (unsigned long long) resource_size(res));
236 	}
237 
238 	return ret;
239 }
240 
241 int pci_reassign_resource(struct pci_dev *dev, int resno, resource_size_t addsize,
242 			resource_size_t min_align)
243 {
244 	struct resource *res = dev->resource + resno;
245 	resource_size_t new_size;
246 	int ret;
247 
248 	if (!res->parent) {
249 		dev_info(&dev->dev, "BAR %d: can't reassign an unassigned resource %pR "
250 			 "\n", resno, res);
251 		return -EINVAL;
252 	}
253 
254 	/* already aligned with min_align */
255 	new_size = resource_size(res) + addsize;
256 	ret = _pci_assign_resource(dev, resno, new_size, min_align);
257 	if (!ret) {
258 		res->flags &= ~IORESOURCE_STARTALIGN;
259 		dev_info(&dev->dev, "BAR %d: reassigned %pR\n", resno, res);
260 		if (resno < PCI_BRIDGE_RESOURCES)
261 			pci_update_resource(dev, resno);
262 	}
263 	return ret;
264 }
265 
266 int pci_assign_resource(struct pci_dev *dev, int resno)
267 {
268 	struct resource *res = dev->resource + resno;
269 	resource_size_t align, size;
270 	struct pci_bus *bus;
271 	int ret;
272 
273 	align = pci_resource_alignment(dev, res);
274 	if (!align) {
275 		dev_info(&dev->dev, "BAR %d: can't assign %pR "
276 			 "(bogus alignment)\n", resno, res);
277 		return -EINVAL;
278 	}
279 
280 	bus = dev->bus;
281 	size = resource_size(res);
282 	ret = _pci_assign_resource(dev, resno, size, align);
283 
284 	/*
285 	 * If we failed to assign anything, let's try the address
286 	 * where firmware left it.  That at least has a chance of
287 	 * working, which is better than just leaving it disabled.
288 	 */
289 	if (ret < 0)
290 		ret = pci_revert_fw_address(res, dev, resno, size);
291 
292 	if (!ret) {
293 		res->flags &= ~IORESOURCE_STARTALIGN;
294 		dev_info(&dev->dev, "BAR %d: assigned %pR\n", resno, res);
295 		if (resno < PCI_BRIDGE_RESOURCES)
296 			pci_update_resource(dev, resno);
297 	}
298 	return ret;
299 }
300 
301 int pci_enable_resources(struct pci_dev *dev, int mask)
302 {
303 	u16 cmd, old_cmd;
304 	int i;
305 	struct resource *r;
306 
307 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
308 	old_cmd = cmd;
309 
310 	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
311 		if (!(mask & (1 << i)))
312 			continue;
313 
314 		r = &dev->resource[i];
315 
316 		if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
317 			continue;
318 		if ((i == PCI_ROM_RESOURCE) &&
319 				(!(r->flags & IORESOURCE_ROM_ENABLE)))
320 			continue;
321 
322 		if (!r->parent) {
323 			dev_err(&dev->dev, "device not available "
324 				"(can't reserve %pR)\n", r);
325 			return -EINVAL;
326 		}
327 
328 		if (r->flags & IORESOURCE_IO)
329 			cmd |= PCI_COMMAND_IO;
330 		if (r->flags & IORESOURCE_MEM)
331 			cmd |= PCI_COMMAND_MEMORY;
332 	}
333 
334 	if (cmd != old_cmd) {
335 		dev_info(&dev->dev, "enabling device (%04x -> %04x)\n",
336 			 old_cmd, cmd);
337 		pci_write_config_word(dev, PCI_COMMAND, cmd);
338 	}
339 	return 0;
340 }
341