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1 #define pr_fmt(fmt)	"OF: PCI: " fmt
2 
3 #include <linux/kernel.h>
4 #include <linux/export.h>
5 #include <linux/of.h>
6 #include <linux/of_address.h>
7 #include <linux/of_device.h>
8 #include <linux/of_pci.h>
9 #include <linux/slab.h>
10 
__of_pci_pci_compare(struct device_node * node,unsigned int data)11 static inline int __of_pci_pci_compare(struct device_node *node,
12 				       unsigned int data)
13 {
14 	int devfn;
15 
16 	devfn = of_pci_get_devfn(node);
17 	if (devfn < 0)
18 		return 0;
19 
20 	return devfn == data;
21 }
22 
of_pci_find_child_device(struct device_node * parent,unsigned int devfn)23 struct device_node *of_pci_find_child_device(struct device_node *parent,
24 					     unsigned int devfn)
25 {
26 	struct device_node *node, *node2;
27 
28 	for_each_child_of_node(parent, node) {
29 		if (__of_pci_pci_compare(node, devfn))
30 			return node;
31 		/*
32 		 * Some OFs create a parent node "multifunc-device" as
33 		 * a fake root for all functions of a multi-function
34 		 * device we go down them as well.
35 		 */
36 		if (!strcmp(node->name, "multifunc-device")) {
37 			for_each_child_of_node(node, node2) {
38 				if (__of_pci_pci_compare(node2, devfn)) {
39 					of_node_put(node);
40 					return node2;
41 				}
42 			}
43 		}
44 	}
45 	return NULL;
46 }
47 EXPORT_SYMBOL_GPL(of_pci_find_child_device);
48 
49 /**
50  * of_pci_get_devfn() - Get device and function numbers for a device node
51  * @np: device node
52  *
53  * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
54  * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
55  * and function numbers respectively. On error a negative error code is
56  * returned.
57  */
of_pci_get_devfn(struct device_node * np)58 int of_pci_get_devfn(struct device_node *np)
59 {
60 	unsigned int size;
61 	const __be32 *reg;
62 
63 	reg = of_get_property(np, "reg", &size);
64 
65 	if (!reg || size < 5 * sizeof(__be32))
66 		return -EINVAL;
67 
68 	return (be32_to_cpup(reg) >> 8) & 0xff;
69 }
70 EXPORT_SYMBOL_GPL(of_pci_get_devfn);
71 
72 /**
73  * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
74  * @node: device node
75  * @res: address to a struct resource to return the bus-range
76  *
77  * Returns 0 on success or a negative error-code on failure.
78  */
of_pci_parse_bus_range(struct device_node * node,struct resource * res)79 int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
80 {
81 	const __be32 *values;
82 	int len;
83 
84 	values = of_get_property(node, "bus-range", &len);
85 	if (!values || len < sizeof(*values) * 2)
86 		return -EINVAL;
87 
88 	res->name = node->name;
89 	res->start = be32_to_cpup(values++);
90 	res->end = be32_to_cpup(values);
91 	res->flags = IORESOURCE_BUS;
92 
93 	return 0;
94 }
95 EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
96 
97 /**
98  * This function will try to obtain the host bridge domain number by
99  * finding a property called "linux,pci-domain" of the given device node.
100  *
101  * @node: device tree node with the domain information
102  *
103  * Returns the associated domain number from DT in the range [0-0xffff], or
104  * a negative value if the required property is not found.
105  */
of_get_pci_domain_nr(struct device_node * node)106 int of_get_pci_domain_nr(struct device_node *node)
107 {
108 	const __be32 *value;
109 	int len;
110 	u16 domain;
111 
112 	value = of_get_property(node, "linux,pci-domain", &len);
113 	if (!value || len < sizeof(*value))
114 		return -EINVAL;
115 
116 	domain = (u16)be32_to_cpup(value);
117 
118 	return domain;
119 }
120 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
121 
122 /**
123  * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
124  *                           is present and valid
125  */
of_pci_check_probe_only(void)126 void of_pci_check_probe_only(void)
127 {
128 	u32 val;
129 	int ret;
130 
131 	ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
132 	if (ret) {
133 		if (ret == -ENODATA || ret == -EOVERFLOW)
134 			pr_warn("linux,pci-probe-only without valid value, ignoring\n");
135 		return;
136 	}
137 
138 	if (val)
139 		pci_add_flags(PCI_PROBE_ONLY);
140 	else
141 		pci_clear_flags(PCI_PROBE_ONLY);
142 
143 	pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
144 }
145 EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
146 
147 #if defined(CONFIG_OF_ADDRESS)
148 /**
149  * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
150  * @dev: device node of the host bridge having the range property
151  * @busno: bus number associated with the bridge root bus
152  * @bus_max: maximum number of buses for this bridge
153  * @resources: list where the range of resources will be added after DT parsing
154  * @io_base: pointer to a variable that will contain on return the physical
155  * address for the start of the I/O range. Can be NULL if the caller doesn't
156  * expect IO ranges to be present in the device tree.
157  *
158  * It is the caller's job to free the @resources list.
159  *
160  * This function will parse the "ranges" property of a PCI host bridge device
161  * node and setup the resource mapping based on its content. It is expected
162  * that the property conforms with the Power ePAPR document.
163  *
164  * It returns zero if the range parsing has been successful or a standard error
165  * value if it failed.
166  */
of_pci_get_host_bridge_resources(struct device_node * dev,unsigned char busno,unsigned char bus_max,struct list_head * resources,resource_size_t * io_base)167 int of_pci_get_host_bridge_resources(struct device_node *dev,
168 			unsigned char busno, unsigned char bus_max,
169 			struct list_head *resources, resource_size_t *io_base)
170 {
171 	struct resource_entry *window;
172 	struct resource *res;
173 	struct resource *bus_range;
174 	struct of_pci_range range;
175 	struct of_pci_range_parser parser;
176 	char range_type[4];
177 	int err;
178 
179 	if (io_base)
180 		*io_base = (resource_size_t)OF_BAD_ADDR;
181 
182 	bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
183 	if (!bus_range)
184 		return -ENOMEM;
185 
186 	pr_info("host bridge %s ranges:\n", dev->full_name);
187 
188 	err = of_pci_parse_bus_range(dev, bus_range);
189 	if (err) {
190 		bus_range->start = busno;
191 		bus_range->end = bus_max;
192 		bus_range->flags = IORESOURCE_BUS;
193 		pr_info("  No bus range found for %s, using %pR\n",
194 			dev->full_name, bus_range);
195 	} else {
196 		if (bus_range->end > bus_range->start + bus_max)
197 			bus_range->end = bus_range->start + bus_max;
198 	}
199 	pci_add_resource(resources, bus_range);
200 
201 	/* Check for ranges property */
202 	err = of_pci_range_parser_init(&parser, dev);
203 	if (err)
204 		goto parse_failed;
205 
206 	pr_debug("Parsing ranges property...\n");
207 	for_each_of_pci_range(&parser, &range) {
208 		/* Read next ranges element */
209 		if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
210 			snprintf(range_type, 4, " IO");
211 		else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
212 			snprintf(range_type, 4, "MEM");
213 		else
214 			snprintf(range_type, 4, "err");
215 		pr_info("  %s %#010llx..%#010llx -> %#010llx\n", range_type,
216 			range.cpu_addr, range.cpu_addr + range.size - 1,
217 			range.pci_addr);
218 
219 		/*
220 		 * If we failed translation or got a zero-sized region
221 		 * then skip this range
222 		 */
223 		if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
224 			continue;
225 
226 		res = kzalloc(sizeof(struct resource), GFP_KERNEL);
227 		if (!res) {
228 			err = -ENOMEM;
229 			goto parse_failed;
230 		}
231 
232 		err = of_pci_range_to_resource(&range, dev, res);
233 		if (err) {
234 			kfree(res);
235 			continue;
236 		}
237 
238 		if (resource_type(res) == IORESOURCE_IO) {
239 			if (!io_base) {
240 				pr_err("I/O range found for %s. Please provide an io_base pointer to save CPU base address\n",
241 					dev->full_name);
242 				err = -EINVAL;
243 				goto conversion_failed;
244 			}
245 			if (*io_base != (resource_size_t)OF_BAD_ADDR)
246 				pr_warn("More than one I/O resource converted for %s. CPU base address for old range lost!\n",
247 					dev->full_name);
248 			*io_base = range.cpu_addr;
249 		}
250 
251 		pci_add_resource_offset(resources, res,	res->start - range.pci_addr);
252 	}
253 
254 	return 0;
255 
256 conversion_failed:
257 	kfree(res);
258 parse_failed:
259 	resource_list_for_each_entry(window, resources)
260 		kfree(window->res);
261 	pci_free_resource_list(resources);
262 	return err;
263 }
264 EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
265 #endif /* CONFIG_OF_ADDRESS */
266 
267 #ifdef CONFIG_PCI_MSI
268 
269 static LIST_HEAD(of_pci_msi_chip_list);
270 static DEFINE_MUTEX(of_pci_msi_chip_mutex);
271 
of_pci_msi_chip_add(struct msi_controller * chip)272 int of_pci_msi_chip_add(struct msi_controller *chip)
273 {
274 	if (!of_property_read_bool(chip->of_node, "msi-controller"))
275 		return -EINVAL;
276 
277 	mutex_lock(&of_pci_msi_chip_mutex);
278 	list_add(&chip->list, &of_pci_msi_chip_list);
279 	mutex_unlock(&of_pci_msi_chip_mutex);
280 
281 	return 0;
282 }
283 EXPORT_SYMBOL_GPL(of_pci_msi_chip_add);
284 
of_pci_msi_chip_remove(struct msi_controller * chip)285 void of_pci_msi_chip_remove(struct msi_controller *chip)
286 {
287 	mutex_lock(&of_pci_msi_chip_mutex);
288 	list_del(&chip->list);
289 	mutex_unlock(&of_pci_msi_chip_mutex);
290 }
291 EXPORT_SYMBOL_GPL(of_pci_msi_chip_remove);
292 
of_pci_find_msi_chip_by_node(struct device_node * of_node)293 struct msi_controller *of_pci_find_msi_chip_by_node(struct device_node *of_node)
294 {
295 	struct msi_controller *c;
296 
297 	mutex_lock(&of_pci_msi_chip_mutex);
298 	list_for_each_entry(c, &of_pci_msi_chip_list, list) {
299 		if (c->of_node == of_node) {
300 			mutex_unlock(&of_pci_msi_chip_mutex);
301 			return c;
302 		}
303 	}
304 	mutex_unlock(&of_pci_msi_chip_mutex);
305 
306 	return NULL;
307 }
308 EXPORT_SYMBOL_GPL(of_pci_find_msi_chip_by_node);
309 
310 #endif /* CONFIG_PCI_MSI */
311 
312 /**
313  * of_pci_map_rid - Translate a requester ID through a downstream mapping.
314  * @np: root complex device node.
315  * @rid: PCI requester ID to map.
316  * @map_name: property name of the map to use.
317  * @map_mask_name: optional property name of the mask to use.
318  * @target: optional pointer to a target device node.
319  * @id_out: optional pointer to receive the translated ID.
320  *
321  * Given a PCI requester ID, look up the appropriate implementation-defined
322  * platform ID and/or the target device which receives transactions on that
323  * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
324  * @id_out may be NULL if only the other is required. If @target points to
325  * a non-NULL device node pointer, only entries targeting that node will be
326  * matched; if it points to a NULL value, it will receive the device node of
327  * the first matching target phandle, with a reference held.
328  *
329  * Return: 0 on success or a standard error code on failure.
330  */
of_pci_map_rid(struct device_node * np,u32 rid,const char * map_name,const char * map_mask_name,struct device_node ** target,u32 * id_out)331 int of_pci_map_rid(struct device_node *np, u32 rid,
332 		   const char *map_name, const char *map_mask_name,
333 		   struct device_node **target, u32 *id_out)
334 {
335 	u32 map_mask, masked_rid;
336 	int map_len;
337 	const __be32 *map = NULL;
338 
339 	if (!np || !map_name || (!target && !id_out))
340 		return -EINVAL;
341 
342 	map = of_get_property(np, map_name, &map_len);
343 	if (!map) {
344 		if (target)
345 			return -ENODEV;
346 		/* Otherwise, no map implies no translation */
347 		*id_out = rid;
348 		return 0;
349 	}
350 
351 	if (!map_len || map_len % (4 * sizeof(*map))) {
352 		pr_err("%s: Error: Bad %s length: %d\n", np->full_name,
353 			map_name, map_len);
354 		return -EINVAL;
355 	}
356 
357 	/* The default is to select all bits. */
358 	map_mask = 0xffffffff;
359 
360 	/*
361 	 * Can be overridden by "{iommu,msi}-map-mask" property.
362 	 * If of_property_read_u32() fails, the default is used.
363 	 */
364 	if (map_mask_name)
365 		of_property_read_u32(np, map_mask_name, &map_mask);
366 
367 	masked_rid = map_mask & rid;
368 	for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
369 		struct device_node *phandle_node;
370 		u32 rid_base = be32_to_cpup(map + 0);
371 		u32 phandle = be32_to_cpup(map + 1);
372 		u32 out_base = be32_to_cpup(map + 2);
373 		u32 rid_len = be32_to_cpup(map + 3);
374 
375 		if (rid_base & ~map_mask) {
376 			pr_err("%s: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
377 				np->full_name, map_name, map_name,
378 				map_mask, rid_base);
379 			return -EFAULT;
380 		}
381 
382 		if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
383 			continue;
384 
385 		phandle_node = of_find_node_by_phandle(phandle);
386 		if (!phandle_node)
387 			return -ENODEV;
388 
389 		if (target) {
390 			if (*target)
391 				of_node_put(phandle_node);
392 			else
393 				*target = phandle_node;
394 
395 			if (*target != phandle_node)
396 				continue;
397 		}
398 
399 		if (id_out)
400 			*id_out = masked_rid - rid_base + out_base;
401 
402 		pr_debug("%s: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
403 			np->full_name, map_name, map_mask, rid_base, out_base,
404 			rid_len, rid, *id_out);
405 		return 0;
406 	}
407 
408 	pr_err("%s: Invalid %s translation - no match for rid 0x%x on %s\n",
409 		np->full_name, map_name, rid,
410 		target && *target ? (*target)->full_name : "any target");
411 	return -EFAULT;
412 }
413