xref: /openbmc/linux/drivers/pci/setup-res.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
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 
29 void pci_update_resource(struct pci_dev *dev, struct resource *res, int resno)
30 {
31 	struct pci_bus_region region;
32 	u32 new, check, mask;
33 	int reg;
34 
35 	/*
36 	 * Ignore resources for unimplemented BARs and unused resource slots
37 	 * for 64 bit BARs.
38 	 */
39 	if (!res->flags)
40 		return;
41 
42 	/*
43 	 * Ignore non-moveable resources.  This might be legacy resources for
44 	 * which no functional BAR register exists or another important
45 	 * system resource we shouldn't move around.
46 	 */
47 	if (res->flags & IORESOURCE_PCI_FIXED)
48 		return;
49 
50 	pcibios_resource_to_bus(dev, &region, res);
51 
52 	dev_dbg(&dev->dev, "BAR %d: got res %pR bus [%#llx-%#llx] "
53 		"flags %#lx\n", resno, res,
54 		 (unsigned long long)region.start,
55 		 (unsigned long long)region.end,
56 		 (unsigned long)res->flags);
57 
58 	new = region.start | (res->flags & PCI_REGION_FLAG_MASK);
59 	if (res->flags & IORESOURCE_IO)
60 		mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
61 	else
62 		mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
63 
64 	if (resno < 6) {
65 		reg = PCI_BASE_ADDRESS_0 + 4 * resno;
66 	} else if (resno == PCI_ROM_RESOURCE) {
67 		if (!(res->flags & IORESOURCE_ROM_ENABLE))
68 			return;
69 		new |= PCI_ROM_ADDRESS_ENABLE;
70 		reg = dev->rom_base_reg;
71 	} else {
72 		/* Hmm, non-standard resource. */
73 
74 		return;		/* kill uninitialised var warning */
75 	}
76 
77 	pci_write_config_dword(dev, reg, new);
78 	pci_read_config_dword(dev, reg, &check);
79 
80 	if ((new ^ check) & mask) {
81 		dev_err(&dev->dev, "BAR %d: error updating (%#08x != %#08x)\n",
82 			resno, new, check);
83 	}
84 
85 	if ((new & (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK)) ==
86 	    (PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64)) {
87 		new = region.start >> 16 >> 16;
88 		pci_write_config_dword(dev, reg + 4, new);
89 		pci_read_config_dword(dev, reg + 4, &check);
90 		if (check != new) {
91 			dev_err(&dev->dev, "BAR %d: error updating "
92 			       "(high %#08x != %#08x)\n", resno, new, check);
93 		}
94 	}
95 	res->flags &= ~IORESOURCE_UNSET;
96 	dev_dbg(&dev->dev, "BAR %d: moved to bus [%#llx-%#llx] flags %#lx\n",
97 		resno, (unsigned long long)region.start,
98 		(unsigned long long)region.end, res->flags);
99 }
100 
101 int pci_claim_resource(struct pci_dev *dev, int resource)
102 {
103 	struct resource *res = &dev->resource[resource];
104 	struct resource *root = NULL;
105 	char *dtype = resource < PCI_BRIDGE_RESOURCES ? "device" : "bridge";
106 	int err;
107 
108 	root = pcibios_select_root(dev, res);
109 
110 	err = -EINVAL;
111 	if (root != NULL)
112 		err = insert_resource(root, res);
113 
114 	if (err) {
115 		dev_err(&dev->dev, "BAR %d: %s of %s %pR\n",
116 			resource,
117 			root ? "address space collision on" :
118 				"no parent found for",
119 			dtype, res);
120 	}
121 
122 	return err;
123 }
124 
125 int pci_assign_resource(struct pci_dev *dev, int resno)
126 {
127 	struct pci_bus *bus = dev->bus;
128 	struct resource *res = dev->resource + resno;
129 	resource_size_t size, min, align;
130 	int ret;
131 
132 	size = resource_size(res);
133 	min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
134 
135 	align = resource_alignment(res);
136 	if (!align) {
137 		dev_err(&dev->dev, "BAR %d: can't allocate resource (bogus "
138 			"alignment) %pR flags %#lx\n",
139 			resno, res, res->flags);
140 		return -EINVAL;
141 	}
142 
143 	/* First, try exact prefetching match.. */
144 	ret = pci_bus_alloc_resource(bus, res, size, align, min,
145 				     IORESOURCE_PREFETCH,
146 				     pcibios_align_resource, dev);
147 
148 	if (ret < 0 && (res->flags & IORESOURCE_PREFETCH)) {
149 		/*
150 		 * That failed.
151 		 *
152 		 * But a prefetching area can handle a non-prefetching
153 		 * window (it will just not perform as well).
154 		 */
155 		ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
156 					     pcibios_align_resource, dev);
157 	}
158 
159 	if (ret) {
160 		dev_err(&dev->dev, "BAR %d: can't allocate %s resource %pR\n",
161 			resno, res->flags & IORESOURCE_IO ? "I/O" : "mem", res);
162 	} else {
163 		res->flags &= ~IORESOURCE_STARTALIGN;
164 		if (resno < PCI_BRIDGE_RESOURCES)
165 			pci_update_resource(dev, res, resno);
166 	}
167 
168 	return ret;
169 }
170 
171 #if 0
172 int pci_assign_resource_fixed(struct pci_dev *dev, int resno)
173 {
174 	struct pci_bus *bus = dev->bus;
175 	struct resource *res = dev->resource + resno;
176 	unsigned int type_mask;
177 	int i, ret = -EBUSY;
178 
179 	type_mask = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH;
180 
181 	for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
182 		struct resource *r = bus->resource[i];
183 		if (!r)
184 			continue;
185 
186 		/* type_mask must match */
187 		if ((res->flags ^ r->flags) & type_mask)
188 			continue;
189 
190 		ret = request_resource(r, res);
191 
192 		if (ret == 0)
193 			break;
194 	}
195 
196 	if (ret) {
197 		dev_err(&dev->dev, "BAR %d: can't allocate %s resource %pR\n",
198 			resno, res->flags & IORESOURCE_IO ? "I/O" : "mem", res);
199 	} else if (resno < PCI_BRIDGE_RESOURCES) {
200 		pci_update_resource(dev, res, resno);
201 	}
202 
203 	return ret;
204 }
205 EXPORT_SYMBOL_GPL(pci_assign_resource_fixed);
206 #endif
207 
208 /* Sort resources by alignment */
209 void pdev_sort_resources(struct pci_dev *dev, struct resource_list *head)
210 {
211 	int i;
212 
213 	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
214 		struct resource *r;
215 		struct resource_list *list, *tmp;
216 		resource_size_t r_align;
217 
218 		r = &dev->resource[i];
219 
220 		if (r->flags & IORESOURCE_PCI_FIXED)
221 			continue;
222 
223 		if (!(r->flags) || r->parent)
224 			continue;
225 
226 		r_align = resource_alignment(r);
227 		if (!r_align) {
228 			dev_warn(&dev->dev, "BAR %d: bogus alignment "
229 				"%pR flags %#lx\n",
230 				i, r, r->flags);
231 			continue;
232 		}
233 		for (list = head; ; list = list->next) {
234 			resource_size_t align = 0;
235 			struct resource_list *ln = list->next;
236 
237 			if (ln)
238 				align = resource_alignment(ln->res);
239 
240 			if (r_align > align) {
241 				tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
242 				if (!tmp)
243 					panic("pdev_sort_resources(): "
244 					      "kmalloc() failed!\n");
245 				tmp->next = ln;
246 				tmp->res = r;
247 				tmp->dev = dev;
248 				list->next = tmp;
249 				break;
250 			}
251 		}
252 	}
253 }
254 
255 int pci_enable_resources(struct pci_dev *dev, int mask)
256 {
257 	u16 cmd, old_cmd;
258 	int i;
259 	struct resource *r;
260 
261 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
262 	old_cmd = cmd;
263 
264 	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
265 		if (!(mask & (1 << i)))
266 			continue;
267 
268 		r = &dev->resource[i];
269 
270 		if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
271 			continue;
272 		if ((i == PCI_ROM_RESOURCE) &&
273 				(!(r->flags & IORESOURCE_ROM_ENABLE)))
274 			continue;
275 
276 		if (!r->parent) {
277 			dev_err(&dev->dev, "device not available because of "
278 				"BAR %d %pR collisions\n", i, r);
279 			return -EINVAL;
280 		}
281 
282 		if (r->flags & IORESOURCE_IO)
283 			cmd |= PCI_COMMAND_IO;
284 		if (r->flags & IORESOURCE_MEM)
285 			cmd |= PCI_COMMAND_MEMORY;
286 	}
287 
288 	if (cmd != old_cmd) {
289 		dev_info(&dev->dev, "enabling device (%04x -> %04x)\n",
290 			 old_cmd, cmd);
291 		pci_write_config_word(dev, PCI_COMMAND, cmd);
292 	}
293 	return 0;
294 }
295