Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
#define pr_fmt(fmt)	"OF: PCI: " fmt

#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_pci.h>
#include <linux/slab.h>

static inline int __of_pci_pci_compare(struct device_node *node,
				       unsigned int data)
{
	int devfn;

	devfn = of_pci_get_devfn(node);
	if (devfn < 0)
		return 0;

	return devfn == data;
}

struct device_node *of_pci_find_child_device(struct device_node *parent,
					     unsigned int devfn)
{
	struct device_node *node, *node2;

	for_each_child_of_node(parent, node) {
		if (__of_pci_pci_compare(node, devfn))
			return node;
		/*
		 * Some OFs create a parent node "multifunc-device" as
		 * a fake root for all functions of a multi-function
		 * device we go down them as well.
		 */
		if (!strcmp(node->name, "multifunc-device")) {
			for_each_child_of_node(node, node2) {
				if (__of_pci_pci_compare(node2, devfn)) {
					of_node_put(node);
					return node2;
				}
			}
		}
	}
	return NULL;
}
EXPORT_SYMBOL_GPL(of_pci_find_child_device);

/**
 * of_pci_get_devfn() - Get device and function numbers for a device node
 * @np: device node
 *
 * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
 * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
 * and function numbers respectively. On error a negative error code is
 * returned.
 */
int of_pci_get_devfn(struct device_node *np)
{
	unsigned int size;
	const __be32 *reg;

	reg = of_get_property(np, "reg", &size);

	if (!reg || size < 5 * sizeof(__be32))
		return -EINVAL;

	return (be32_to_cpup(reg) >> 8) & 0xff;
}
EXPORT_SYMBOL_GPL(of_pci_get_devfn);

/**
 * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
 * @node: device node
 * @res: address to a struct resource to return the bus-range
 *
 * Returns 0 on success or a negative error-code on failure.
 */
int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
{
	const __be32 *values;
	int len;

	values = of_get_property(node, "bus-range", &len);
	if (!values || len < sizeof(*values) * 2)
		return -EINVAL;

	res->name = node->name;
	res->start = be32_to_cpup(values++);
	res->end = be32_to_cpup(values);
	res->flags = IORESOURCE_BUS;

	return 0;
}
EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);

/**
 * This function will try to obtain the host bridge domain number by
 * finding a property called "linux,pci-domain" of the given device node.
 *
 * @node: device tree node with the domain information
 *
 * Returns the associated domain number from DT in the range [0-0xffff], or
 * a negative value if the required property is not found.
 */
int of_get_pci_domain_nr(struct device_node *node)
{
	const __be32 *value;
	int len;
	u16 domain;

	value = of_get_property(node, "linux,pci-domain", &len);
	if (!value || len < sizeof(*value))
		return -EINVAL;

	domain = (u16)be32_to_cpup(value);

	return domain;
}
EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);

/**
 * This function will try to find the limitation of link speed by finding
 * a property called "max-link-speed" of the given device node.
 *
 * @node: device tree node with the max link speed information
 *
 * Returns the associated max link speed from DT, or a negative value if the
 * required property is not found or is invalid.
 */
int of_pci_get_max_link_speed(struct device_node *node)
{
	u32 max_link_speed;

	if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
	    max_link_speed > 4)
		return -EINVAL;

	return max_link_speed;
}
EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);

/**
 * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
 *                           is present and valid
 */
void of_pci_check_probe_only(void)
{
	u32 val;
	int ret;

	ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
	if (ret) {
		if (ret == -ENODATA || ret == -EOVERFLOW)
			pr_warn("linux,pci-probe-only without valid value, ignoring\n");
		return;
	}

	if (val)
		pci_add_flags(PCI_PROBE_ONLY);
	else
		pci_clear_flags(PCI_PROBE_ONLY);

	pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
}
EXPORT_SYMBOL_GPL(of_pci_check_probe_only);

#if defined(CONFIG_OF_ADDRESS)
/**
 * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
 * @dev: device node of the host bridge having the range property
 * @busno: bus number associated with the bridge root bus
 * @bus_max: maximum number of buses for this bridge
 * @resources: list where the range of resources will be added after DT parsing
 * @io_base: pointer to a variable that will contain on return the physical
 * address for the start of the I/O range. Can be NULL if the caller doesn't
 * expect IO ranges to be present in the device tree.
 *
 * It is the caller's job to free the @resources list.
 *
 * This function will parse the "ranges" property of a PCI host bridge device
 * node and setup the resource mapping based on its content. It is expected
 * that the property conforms with the Power ePAPR document.
 *
 * It returns zero if the range parsing has been successful or a standard error
 * value if it failed.
 */
int 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)
{
	struct resource_entry *window;
	struct resource *res;
	struct resource *bus_range;
	struct of_pci_range range;
	struct of_pci_range_parser parser;
	char range_type[4];
	int err;

	if (io_base)
		*io_base = (resource_size_t)OF_BAD_ADDR;

	bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
	if (!bus_range)
		return -ENOMEM;

	pr_info("host bridge %s ranges:\n", dev->full_name);

	err = of_pci_parse_bus_range(dev, bus_range);
	if (err) {
		bus_range->start = busno;
		bus_range->end = bus_max;
		bus_range->flags = IORESOURCE_BUS;
		pr_info("  No bus range found for %s, using %pR\n",
			dev->full_name, bus_range);
	} else {
		if (bus_range->end > bus_range->start + bus_max)
			bus_range->end = bus_range->start + bus_max;
	}
	pci_add_resource(resources, bus_range);

	/* Check for ranges property */
	err = of_pci_range_parser_init(&parser, dev);
	if (err)
		goto parse_failed;

	pr_debug("Parsing ranges property...\n");
	for_each_of_pci_range(&parser, &range) {
		/* Read next ranges element */
		if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
			snprintf(range_type, 4, " IO");
		else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
			snprintf(range_type, 4, "MEM");
		else
			snprintf(range_type, 4, "err");
		pr_info("  %s %#010llx..%#010llx -> %#010llx\n", range_type,
			range.cpu_addr, range.cpu_addr + range.size - 1,
			range.pci_addr);

		/*
		 * If we failed translation or got a zero-sized region
		 * then skip this range
		 */
		if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
			continue;

		res = kzalloc(sizeof(struct resource), GFP_KERNEL);
		if (!res) {
			err = -ENOMEM;
			goto parse_failed;
		}

		err = of_pci_range_to_resource(&range, dev, res);
		if (err) {
			kfree(res);
			continue;
		}

		if (resource_type(res) == IORESOURCE_IO) {
			if (!io_base) {
				pr_err("I/O range found for %s. Please provide an io_base pointer to save CPU base address\n",
					dev->full_name);
				err = -EINVAL;
				goto conversion_failed;
			}
			if (*io_base != (resource_size_t)OF_BAD_ADDR)
				pr_warn("More than one I/O resource converted for %s. CPU base address for old range lost!\n",
					dev->full_name);
			*io_base = range.cpu_addr;
		}

		pci_add_resource_offset(resources, res,	res->start - range.pci_addr);
	}

	return 0;

conversion_failed:
	kfree(res);
parse_failed:
	resource_list_for_each_entry(window, resources)
		kfree(window->res);
	pci_free_resource_list(resources);
	return err;
}
EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
#endif /* CONFIG_OF_ADDRESS */

#ifdef CONFIG_PCI_MSI

static LIST_HEAD(of_pci_msi_chip_list);
static DEFINE_MUTEX(of_pci_msi_chip_mutex);

int of_pci_msi_chip_add(struct msi_controller *chip)
{
	if (!of_property_read_bool(chip->of_node, "msi-controller"))
		return -EINVAL;

	mutex_lock(&of_pci_msi_chip_mutex);
	list_add(&chip->list, &of_pci_msi_chip_list);
	mutex_unlock(&of_pci_msi_chip_mutex);

	return 0;
}
EXPORT_SYMBOL_GPL(of_pci_msi_chip_add);

void of_pci_msi_chip_remove(struct msi_controller *chip)
{
	mutex_lock(&of_pci_msi_chip_mutex);
	list_del(&chip->list);
	mutex_unlock(&of_pci_msi_chip_mutex);
}
EXPORT_SYMBOL_GPL(of_pci_msi_chip_remove);

struct msi_controller *of_pci_find_msi_chip_by_node(struct device_node *of_node)
{
	struct msi_controller *c;

	mutex_lock(&of_pci_msi_chip_mutex);
	list_for_each_entry(c, &of_pci_msi_chip_list, list) {
		if (c->of_node == of_node) {
			mutex_unlock(&of_pci_msi_chip_mutex);
			return c;
		}
	}
	mutex_unlock(&of_pci_msi_chip_mutex);

	return NULL;
}
EXPORT_SYMBOL_GPL(of_pci_find_msi_chip_by_node);

#endif /* CONFIG_PCI_MSI */

/**
 * of_pci_map_rid - Translate a requester ID through a downstream mapping.
 * @np: root complex device node.
 * @rid: PCI requester ID to map.
 * @map_name: property name of the map to use.
 * @map_mask_name: optional property name of the mask to use.
 * @target: optional pointer to a target device node.
 * @id_out: optional pointer to receive the translated ID.
 *
 * Given a PCI requester ID, look up the appropriate implementation-defined
 * platform ID and/or the target device which receives transactions on that
 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
 * @id_out may be NULL if only the other is required. If @target points to
 * a non-NULL device node pointer, only entries targeting that node will be
 * matched; if it points to a NULL value, it will receive the device node of
 * the first matching target phandle, with a reference held.
 *
 * Return: 0 on success or a standard error code on failure.
 */
int 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)
{
	u32 map_mask, masked_rid;
	int map_len;
	const __be32 *map = NULL;

	if (!np || !map_name || (!target && !id_out))
		return -EINVAL;

	map = of_get_property(np, map_name, &map_len);
	if (!map) {
		if (target)
			return -ENODEV;
		/* Otherwise, no map implies no translation */
		*id_out = rid;
		return 0;
	}

	if (!map_len || map_len % (4 * sizeof(*map))) {
		pr_err("%s: Error: Bad %s length: %d\n", np->full_name,
			map_name, map_len);
		return -EINVAL;
	}

	/* The default is to select all bits. */
	map_mask = 0xffffffff;

	/*
	 * Can be overridden by "{iommu,msi}-map-mask" property.
	 * If of_property_read_u32() fails, the default is used.
	 */
	if (map_mask_name)
		of_property_read_u32(np, map_mask_name, &map_mask);

	masked_rid = map_mask & rid;
	for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
		struct device_node *phandle_node;
		u32 rid_base = be32_to_cpup(map + 0);
		u32 phandle = be32_to_cpup(map + 1);
		u32 out_base = be32_to_cpup(map + 2);
		u32 rid_len = be32_to_cpup(map + 3);

		if (rid_base & ~map_mask) {
			pr_err("%s: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
				np->full_name, map_name, map_name,
				map_mask, rid_base);
			return -EFAULT;
		}

		if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
			continue;

		phandle_node = of_find_node_by_phandle(phandle);
		if (!phandle_node)
			return -ENODEV;

		if (target) {
			if (*target)
				of_node_put(phandle_node);
			else
				*target = phandle_node;

			if (*target != phandle_node)
				continue;
		}

		if (id_out)
			*id_out = masked_rid - rid_base + out_base;

		pr_debug("%s: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
			np->full_name, map_name, map_mask, rid_base, out_base,
			rid_len, rid, *id_out);
		return 0;
	}

	pr_err("%s: Invalid %s translation - no match for rid 0x%x on %s\n",
		np->full_name, map_name, rid,
		target && *target ? (*target)->full_name : "any target");
	return -EFAULT;
}