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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/pci.h>
22 #include <linux/errno.h>
23 #include <linux/ioport.h>
24 #include <linux/cache.h>
25 #include <linux/slab.h>
26 #include "pci.h"
27 
28 
pci_update_resource(struct pci_dev * dev,int resno)29 void pci_update_resource(struct pci_dev *dev, int resno)
30 {
31 	struct pci_bus_region region;
32 	u32 new, check, mask;
33 	int reg;
34 	enum pci_bar_type type;
35 	struct resource *res = dev->resource + resno;
36 
37 	/*
38 	 * Ignore resources for unimplemented BARs and unused resource slots
39 	 * for 64 bit BARs.
40 	 */
41 	if (!res->flags)
42 		return;
43 
44 	/*
45 	 * Ignore non-moveable resources.  This might be legacy resources for
46 	 * which no functional BAR register exists or another important
47 	 * system resource we shouldn't move around.
48 	 */
49 	if (res->flags & IORESOURCE_PCI_FIXED)
50 		return;
51 
52 	pcibios_resource_to_bus(dev, &region, res);
53 
54 	dev_dbg(&dev->dev, "BAR %d: got res %pR bus [%#llx-%#llx] "
55 		"flags %#lx\n", resno, res,
56 		 (unsigned long long)region.start,
57 		 (unsigned long long)region.end,
58 		 (unsigned long)res->flags);
59 
60 	new = region.start | (res->flags & PCI_REGION_FLAG_MASK);
61 	if (res->flags & IORESOURCE_IO)
62 		mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
63 	else
64 		mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
65 
66 	reg = pci_resource_bar(dev, resno, &type);
67 	if (!reg)
68 		return;
69 	if (type != pci_bar_unknown) {
70 		if (!(res->flags & IORESOURCE_ROM_ENABLE))
71 			return;
72 		new |= PCI_ROM_ADDRESS_ENABLE;
73 	}
74 
75 	pci_write_config_dword(dev, reg, new);
76 	pci_read_config_dword(dev, reg, &check);
77 
78 	if ((new ^ check) & mask) {
79 		dev_err(&dev->dev, "BAR %d: error updating (%#08x != %#08x)\n",
80 			resno, new, check);
81 	}
82 
83 	if ((new & (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK)) ==
84 	    (PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64)) {
85 		new = region.start >> 16 >> 16;
86 		pci_write_config_dword(dev, reg + 4, new);
87 		pci_read_config_dword(dev, reg + 4, &check);
88 		if (check != new) {
89 			dev_err(&dev->dev, "BAR %d: error updating "
90 			       "(high %#08x != %#08x)\n", resno, new, check);
91 		}
92 	}
93 	res->flags &= ~IORESOURCE_UNSET;
94 	dev_dbg(&dev->dev, "BAR %d: moved to bus [%#llx-%#llx] flags %#lx\n",
95 		resno, (unsigned long long)region.start,
96 		(unsigned long long)region.end, res->flags);
97 }
98 
pci_claim_resource(struct pci_dev * dev,int resource)99 int pci_claim_resource(struct pci_dev *dev, int resource)
100 {
101 	struct resource *res = &dev->resource[resource];
102 	struct resource *root = NULL;
103 	char *dtype = resource < PCI_BRIDGE_RESOURCES ? "device" : "bridge";
104 	int err;
105 
106 	root = pcibios_select_root(dev, res);
107 
108 	err = -EINVAL;
109 	if (root != NULL)
110 		err = insert_resource(root, res);
111 
112 	if (err) {
113 		dev_err(&dev->dev, "BAR %d: %s of %s %pR\n",
114 			resource,
115 			root ? "address space collision on" :
116 				"no parent found for",
117 			dtype, res);
118 	}
119 
120 	return err;
121 }
122 
pci_assign_resource(struct pci_dev * dev,int resno)123 int pci_assign_resource(struct pci_dev *dev, int resno)
124 {
125 	struct pci_bus *bus = dev->bus;
126 	struct resource *res = dev->resource + resno;
127 	resource_size_t size, min, align;
128 	int ret;
129 
130 	size = resource_size(res);
131 	min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
132 
133 	align = resource_alignment(res);
134 	if (!align) {
135 		dev_info(&dev->dev, "BAR %d: can't allocate resource (bogus "
136 			"alignment) %pR flags %#lx\n",
137 			resno, res, res->flags);
138 		return -EINVAL;
139 	}
140 
141 	/* First, try exact prefetching match.. */
142 	ret = pci_bus_alloc_resource(bus, res, size, align, min,
143 				     IORESOURCE_PREFETCH,
144 				     pcibios_align_resource, dev);
145 
146 	if (ret < 0 && (res->flags & IORESOURCE_PREFETCH)) {
147 		/*
148 		 * That failed.
149 		 *
150 		 * But a prefetching area can handle a non-prefetching
151 		 * window (it will just not perform as well).
152 		 */
153 		ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
154 					     pcibios_align_resource, dev);
155 	}
156 
157 	if (ret) {
158 		dev_info(&dev->dev, "BAR %d: can't allocate %s resource %pR\n",
159 			resno, res->flags & IORESOURCE_IO ? "I/O" : "mem", res);
160 	} else {
161 		res->flags &= ~IORESOURCE_STARTALIGN;
162 		if (resno < PCI_BRIDGE_RESOURCES)
163 			pci_update_resource(dev, resno);
164 	}
165 
166 	return ret;
167 }
168 
169 #if 0
170 int pci_assign_resource_fixed(struct pci_dev *dev, int resno)
171 {
172 	struct pci_bus *bus = dev->bus;
173 	struct resource *res = dev->resource + resno;
174 	unsigned int type_mask;
175 	int i, ret = -EBUSY;
176 
177 	type_mask = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH;
178 
179 	for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
180 		struct resource *r = bus->resource[i];
181 		if (!r)
182 			continue;
183 
184 		/* type_mask must match */
185 		if ((res->flags ^ r->flags) & type_mask)
186 			continue;
187 
188 		ret = request_resource(r, res);
189 
190 		if (ret == 0)
191 			break;
192 	}
193 
194 	if (ret) {
195 		dev_err(&dev->dev, "BAR %d: can't allocate %s resource %pR\n",
196 			resno, res->flags & IORESOURCE_IO ? "I/O" : "mem", res);
197 	} else if (resno < PCI_BRIDGE_RESOURCES) {
198 		pci_update_resource(dev, resno);
199 	}
200 
201 	return ret;
202 }
203 EXPORT_SYMBOL_GPL(pci_assign_resource_fixed);
204 #endif
205 
206 /* Sort resources by alignment */
pdev_sort_resources(struct pci_dev * dev,struct resource_list * head)207 void pdev_sort_resources(struct pci_dev *dev, struct resource_list *head)
208 {
209 	int i;
210 
211 	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
212 		struct resource *r;
213 		struct resource_list *list, *tmp;
214 		resource_size_t r_align;
215 
216 		r = &dev->resource[i];
217 
218 		if (r->flags & IORESOURCE_PCI_FIXED)
219 			continue;
220 
221 		if (!(r->flags) || r->parent)
222 			continue;
223 
224 		r_align = resource_alignment(r);
225 		if (!r_align) {
226 			dev_warn(&dev->dev, "BAR %d: bogus alignment "
227 				"%pR flags %#lx\n",
228 				i, r, r->flags);
229 			continue;
230 		}
231 		for (list = head; ; list = list->next) {
232 			resource_size_t align = 0;
233 			struct resource_list *ln = list->next;
234 
235 			if (ln)
236 				align = resource_alignment(ln->res);
237 
238 			if (r_align > align) {
239 				tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
240 				if (!tmp)
241 					panic("pdev_sort_resources(): "
242 					      "kmalloc() failed!\n");
243 				tmp->next = ln;
244 				tmp->res = r;
245 				tmp->dev = dev;
246 				list->next = tmp;
247 				break;
248 			}
249 		}
250 	}
251 }
252 
pci_enable_resources(struct pci_dev * dev,int mask)253 int pci_enable_resources(struct pci_dev *dev, int mask)
254 {
255 	u16 cmd, old_cmd;
256 	int i;
257 	struct resource *r;
258 
259 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
260 	old_cmd = cmd;
261 
262 	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
263 		if (!(mask & (1 << i)))
264 			continue;
265 
266 		r = &dev->resource[i];
267 
268 		if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
269 			continue;
270 		if ((i == PCI_ROM_RESOURCE) &&
271 				(!(r->flags & IORESOURCE_ROM_ENABLE)))
272 			continue;
273 
274 		if (!r->parent) {
275 			dev_err(&dev->dev, "device not available because of "
276 				"BAR %d %pR collisions\n", i, r);
277 			return -EINVAL;
278 		}
279 
280 		if (r->flags & IORESOURCE_IO)
281 			cmd |= PCI_COMMAND_IO;
282 		if (r->flags & IORESOURCE_MEM)
283 			cmd |= PCI_COMMAND_MEMORY;
284 	}
285 
286 	if (cmd != old_cmd) {
287 		dev_info(&dev->dev, "enabling device (%04x -> %04x)\n",
288 			 old_cmd, cmd);
289 		pci_write_config_word(dev, PCI_COMMAND, cmd);
290 	}
291 	return 0;
292 }
293