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
 11static 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
 23struct 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}
 47EXPORT_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 */
 58int 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}
 70EXPORT_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 */
 79int 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}
 95EXPORT_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 */
106int 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}
120EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
121
122/**
123 * This function will try to find the limitation of link speed by finding
124 * a property called "max-link-speed" of the given device node.
125 *
126 * @node: device tree node with the max link speed information
127 *
128 * Returns the associated max link speed from DT, or a negative value if the
129 * required property is not found or is invalid.
130 */
131int of_pci_get_max_link_speed(struct device_node *node)
132{
133	u32 max_link_speed;
134
135	if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
136	    max_link_speed > 4)
137		return -EINVAL;
138
139	return max_link_speed;
140}
141EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);
142
143/**
144 * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
145 *                           is present and valid
146 */
147void of_pci_check_probe_only(void)
148{
149	u32 val;
150	int ret;
151
152	ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
153	if (ret) {
154		if (ret == -ENODATA || ret == -EOVERFLOW)
155			pr_warn("linux,pci-probe-only without valid value, ignoring\n");
156		return;
157	}
158
159	if (val)
160		pci_add_flags(PCI_PROBE_ONLY);
161	else
162		pci_clear_flags(PCI_PROBE_ONLY);
163
164	pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
165}
166EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
167
168#if defined(CONFIG_OF_ADDRESS)
169/**
170 * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
171 * @dev: device node of the host bridge having the range property
172 * @busno: bus number associated with the bridge root bus
173 * @bus_max: maximum number of buses for this bridge
174 * @resources: list where the range of resources will be added after DT parsing
175 * @io_base: pointer to a variable that will contain on return the physical
176 * address for the start of the I/O range. Can be NULL if the caller doesn't
177 * expect IO ranges to be present in the device tree.
178 *
179 * It is the caller's job to free the @resources list.
180 *
181 * This function will parse the "ranges" property of a PCI host bridge device
182 * node and setup the resource mapping based on its content. It is expected
183 * that the property conforms with the Power ePAPR document.
184 *
185 * It returns zero if the range parsing has been successful or a standard error
186 * value if it failed.
187 */
188int of_pci_get_host_bridge_resources(struct device_node *dev,
189			unsigned char busno, unsigned char bus_max,
190			struct list_head *resources, resource_size_t *io_base)
191{
192	struct resource_entry *window;
193	struct resource *res;
194	struct resource *bus_range;
195	struct of_pci_range range;
196	struct of_pci_range_parser parser;
197	char range_type[4];
198	int err;
199
200	if (io_base)
201		*io_base = (resource_size_t)OF_BAD_ADDR;
202
203	bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
204	if (!bus_range)
205		return -ENOMEM;
206
207	pr_info("host bridge %s ranges:\n", dev->full_name);
208
209	err = of_pci_parse_bus_range(dev, bus_range);
210	if (err) {
211		bus_range->start = busno;
212		bus_range->end = bus_max;
213		bus_range->flags = IORESOURCE_BUS;
214		pr_info("  No bus range found for %s, using %pR\n",
215			dev->full_name, bus_range);
216	} else {
217		if (bus_range->end > bus_range->start + bus_max)
218			bus_range->end = bus_range->start + bus_max;
219	}
220	pci_add_resource(resources, bus_range);
221
222	/* Check for ranges property */
223	err = of_pci_range_parser_init(&parser, dev);
224	if (err)
225		goto parse_failed;
226
227	pr_debug("Parsing ranges property...\n");
228	for_each_of_pci_range(&parser, &range) {
229		/* Read next ranges element */
230		if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
231			snprintf(range_type, 4, " IO");
232		else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
233			snprintf(range_type, 4, "MEM");
234		else
235			snprintf(range_type, 4, "err");
236		pr_info("  %s %#010llx..%#010llx -> %#010llx\n", range_type,
237			range.cpu_addr, range.cpu_addr + range.size - 1,
238			range.pci_addr);
239
240		/*
241		 * If we failed translation or got a zero-sized region
242		 * then skip this range
243		 */
244		if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
245			continue;
246
247		res = kzalloc(sizeof(struct resource), GFP_KERNEL);
248		if (!res) {
249			err = -ENOMEM;
250			goto parse_failed;
251		}
252
253		err = of_pci_range_to_resource(&range, dev, res);
254		if (err) {
255			kfree(res);
256			continue;
257		}
258
259		if (resource_type(res) == IORESOURCE_IO) {
260			if (!io_base) {
261				pr_err("I/O range found for %s. Please provide an io_base pointer to save CPU base address\n",
262					dev->full_name);
263				err = -EINVAL;
264				goto conversion_failed;
265			}
266			if (*io_base != (resource_size_t)OF_BAD_ADDR)
267				pr_warn("More than one I/O resource converted for %s. CPU base address for old range lost!\n",
268					dev->full_name);
269			*io_base = range.cpu_addr;
270		}
271
272		pci_add_resource_offset(resources, res,	res->start - range.pci_addr);
273	}
274
275	return 0;
276
277conversion_failed:
278	kfree(res);
279parse_failed:
280	resource_list_for_each_entry(window, resources)
281		kfree(window->res);
282	pci_free_resource_list(resources);
283	return err;
284}
285EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
286#endif /* CONFIG_OF_ADDRESS */
287
288#ifdef CONFIG_PCI_MSI
289
290static LIST_HEAD(of_pci_msi_chip_list);
291static DEFINE_MUTEX(of_pci_msi_chip_mutex);
292
293int of_pci_msi_chip_add(struct msi_controller *chip)
294{
295	if (!of_property_read_bool(chip->of_node, "msi-controller"))
296		return -EINVAL;
297
298	mutex_lock(&of_pci_msi_chip_mutex);
299	list_add(&chip->list, &of_pci_msi_chip_list);
300	mutex_unlock(&of_pci_msi_chip_mutex);
301
302	return 0;
303}
304EXPORT_SYMBOL_GPL(of_pci_msi_chip_add);
305
306void of_pci_msi_chip_remove(struct msi_controller *chip)
307{
308	mutex_lock(&of_pci_msi_chip_mutex);
309	list_del(&chip->list);
310	mutex_unlock(&of_pci_msi_chip_mutex);
311}
312EXPORT_SYMBOL_GPL(of_pci_msi_chip_remove);
313
314struct msi_controller *of_pci_find_msi_chip_by_node(struct device_node *of_node)
315{
316	struct msi_controller *c;
317
318	mutex_lock(&of_pci_msi_chip_mutex);
319	list_for_each_entry(c, &of_pci_msi_chip_list, list) {
320		if (c->of_node == of_node) {
321			mutex_unlock(&of_pci_msi_chip_mutex);
322			return c;
323		}
324	}
325	mutex_unlock(&of_pci_msi_chip_mutex);
326
327	return NULL;
328}
329EXPORT_SYMBOL_GPL(of_pci_find_msi_chip_by_node);
330
331#endif /* CONFIG_PCI_MSI */
332
333/**
334 * of_pci_map_rid - Translate a requester ID through a downstream mapping.
335 * @np: root complex device node.
336 * @rid: PCI requester ID to map.
337 * @map_name: property name of the map to use.
338 * @map_mask_name: optional property name of the mask to use.
339 * @target: optional pointer to a target device node.
340 * @id_out: optional pointer to receive the translated ID.
341 *
342 * Given a PCI requester ID, look up the appropriate implementation-defined
343 * platform ID and/or the target device which receives transactions on that
344 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
345 * @id_out may be NULL if only the other is required. If @target points to
346 * a non-NULL device node pointer, only entries targeting that node will be
347 * matched; if it points to a NULL value, it will receive the device node of
348 * the first matching target phandle, with a reference held.
349 *
350 * Return: 0 on success or a standard error code on failure.
351 */
352int of_pci_map_rid(struct device_node *np, u32 rid,
353		   const char *map_name, const char *map_mask_name,
354		   struct device_node **target, u32 *id_out)
355{
356	u32 map_mask, masked_rid;
357	int map_len;
358	const __be32 *map = NULL;
359
360	if (!np || !map_name || (!target && !id_out))
361		return -EINVAL;
362
363	map = of_get_property(np, map_name, &map_len);
364	if (!map) {
365		if (target)
366			return -ENODEV;
367		/* Otherwise, no map implies no translation */
368		*id_out = rid;
369		return 0;
370	}
371
372	if (!map_len || map_len % (4 * sizeof(*map))) {
373		pr_err("%s: Error: Bad %s length: %d\n", np->full_name,
374			map_name, map_len);
375		return -EINVAL;
376	}
377
378	/* The default is to select all bits. */
379	map_mask = 0xffffffff;
380
381	/*
382	 * Can be overridden by "{iommu,msi}-map-mask" property.
383	 * If of_property_read_u32() fails, the default is used.
384	 */
385	if (map_mask_name)
386		of_property_read_u32(np, map_mask_name, &map_mask);
387
388	masked_rid = map_mask & rid;
389	for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
390		struct device_node *phandle_node;
391		u32 rid_base = be32_to_cpup(map + 0);
392		u32 phandle = be32_to_cpup(map + 1);
393		u32 out_base = be32_to_cpup(map + 2);
394		u32 rid_len = be32_to_cpup(map + 3);
395
396		if (rid_base & ~map_mask) {
397			pr_err("%s: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
398				np->full_name, map_name, map_name,
399				map_mask, rid_base);
400			return -EFAULT;
401		}
402
403		if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
404			continue;
405
406		phandle_node = of_find_node_by_phandle(phandle);
407		if (!phandle_node)
408			return -ENODEV;
409
410		if (target) {
411			if (*target)
412				of_node_put(phandle_node);
413			else
414				*target = phandle_node;
415
416			if (*target != phandle_node)
417				continue;
418		}
419
420		if (id_out)
421			*id_out = masked_rid - rid_base + out_base;
422
423		pr_debug("%s: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
424			np->full_name, map_name, map_mask, rid_base, out_base,
425			rid_len, rid, *id_out);
426		return 0;
427	}
428
429	pr_err("%s: Invalid %s translation - no match for rid 0x%x on %s\n",
430		np->full_name, map_name, rid,
431		target && *target ? (*target)->full_name : "any target");
432	return -EFAULT;
433}