1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/string.h>
3 #include <linux/kernel.h>
4 #include <linux/of.h>
5 #include <linux/of_device.h>
6 #include <linux/of_address.h>
7 #include <linux/of_iommu.h>
8 #include <linux/of_reserved_mem.h>
9 #include <linux/dma-direct.h> /* for bus_dma_region */
10 #include <linux/dma-map-ops.h>
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/mod_devicetable.h>
14 #include <linux/slab.h>
15 #include <linux/platform_device.h>
16 
17 #include <asm/errno.h>
18 #include "of_private.h"
19 
20 /**
21  * of_match_device - Tell if a struct device matches an of_device_id list
22  * @matches: array of of device match structures to search in
23  * @dev: the of device structure to match against
24  *
25  * Used by a driver to check whether an platform_device present in the
26  * system is in its list of supported devices.
27  */
of_match_device(const struct of_device_id * matches,const struct device * dev)28 const struct of_device_id *of_match_device(const struct of_device_id *matches,
29 					   const struct device *dev)
30 {
31 	if (!matches || !dev->of_node || dev->of_node_reused)
32 		return NULL;
33 	return of_match_node(matches, dev->of_node);
34 }
35 EXPORT_SYMBOL(of_match_device);
36 
of_device_add(struct platform_device * ofdev)37 int of_device_add(struct platform_device *ofdev)
38 {
39 	BUG_ON(ofdev->dev.of_node == NULL);
40 
41 	/* name and id have to be set so that the platform bus doesn't get
42 	 * confused on matching */
43 	ofdev->name = dev_name(&ofdev->dev);
44 	ofdev->id = PLATFORM_DEVID_NONE;
45 
46 	/*
47 	 * If this device has not binding numa node in devicetree, that is
48 	 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
49 	 * device is on the same node as the parent.
50 	 */
51 	set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
52 
53 	return device_add(&ofdev->dev);
54 }
55 
56 static void
of_dma_set_restricted_buffer(struct device * dev,struct device_node * np)57 of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)
58 {
59 	struct device_node *node, *of_node = dev->of_node;
60 	int count, i;
61 
62 	if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL))
63 		return;
64 
65 	count = of_property_count_elems_of_size(of_node, "memory-region",
66 						sizeof(u32));
67 	/*
68 	 * If dev->of_node doesn't exist or doesn't contain memory-region, try
69 	 * the OF node having DMA configuration.
70 	 */
71 	if (count <= 0) {
72 		of_node = np;
73 		count = of_property_count_elems_of_size(
74 			of_node, "memory-region", sizeof(u32));
75 	}
76 
77 	for (i = 0; i < count; i++) {
78 		node = of_parse_phandle(of_node, "memory-region", i);
79 		/*
80 		 * There might be multiple memory regions, but only one
81 		 * restricted-dma-pool region is allowed.
82 		 */
83 		if (of_device_is_compatible(node, "restricted-dma-pool") &&
84 		    of_device_is_available(node)) {
85 			of_node_put(node);
86 			break;
87 		}
88 		of_node_put(node);
89 	}
90 
91 	/*
92 	 * Attempt to initialize a restricted-dma-pool region if one was found.
93 	 * Note that count can hold a negative error code.
94 	 */
95 	if (i < count && of_reserved_mem_device_init_by_idx(dev, of_node, i))
96 		dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
97 }
98 
99 /**
100  * of_dma_configure_id - Setup DMA configuration
101  * @dev:	Device to apply DMA configuration
102  * @np:		Pointer to OF node having DMA configuration
103  * @force_dma:  Whether device is to be set up by of_dma_configure() even if
104  *		DMA capability is not explicitly described by firmware.
105  * @id:		Optional const pointer value input id
106  *
107  * Try to get devices's DMA configuration from DT and update it
108  * accordingly.
109  *
110  * If platform code needs to use its own special DMA configuration, it
111  * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
112  * to fix up DMA configuration.
113  */
of_dma_configure_id(struct device * dev,struct device_node * np,bool force_dma,const u32 * id)114 int of_dma_configure_id(struct device *dev, struct device_node *np,
115 			bool force_dma, const u32 *id)
116 {
117 	const struct iommu_ops *iommu;
118 	const struct bus_dma_region *map = NULL;
119 	u64 dma_start = 0;
120 	u64 mask, end, size = 0;
121 	bool coherent;
122 	int ret;
123 
124 	ret = of_dma_get_range(np, &map);
125 	if (ret < 0) {
126 		/*
127 		 * For legacy reasons, we have to assume some devices need
128 		 * DMA configuration regardless of whether "dma-ranges" is
129 		 * correctly specified or not.
130 		 */
131 		if (!force_dma)
132 			return ret == -ENODEV ? 0 : ret;
133 	} else {
134 		const struct bus_dma_region *r = map;
135 		u64 dma_end = 0;
136 
137 		/* Determine the overall bounds of all DMA regions */
138 		for (dma_start = ~0; r->size; r++) {
139 			/* Take lower and upper limits */
140 			if (r->dma_start < dma_start)
141 				dma_start = r->dma_start;
142 			if (r->dma_start + r->size > dma_end)
143 				dma_end = r->dma_start + r->size;
144 		}
145 		size = dma_end - dma_start;
146 
147 		/*
148 		 * Add a work around to treat the size as mask + 1 in case
149 		 * it is defined in DT as a mask.
150 		 */
151 		if (size & 1) {
152 			dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n",
153 				 size);
154 			size = size + 1;
155 		}
156 
157 		if (!size) {
158 			dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
159 			kfree(map);
160 			return -EINVAL;
161 		}
162 	}
163 
164 	/*
165 	 * If @dev is expected to be DMA-capable then the bus code that created
166 	 * it should have initialised its dma_mask pointer by this point. For
167 	 * now, we'll continue the legacy behaviour of coercing it to the
168 	 * coherent mask if not, but we'll no longer do so quietly.
169 	 */
170 	if (!dev->dma_mask) {
171 		dev_warn(dev, "DMA mask not set\n");
172 		dev->dma_mask = &dev->coherent_dma_mask;
173 	}
174 
175 	if (!size && dev->coherent_dma_mask)
176 		size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
177 	else if (!size)
178 		size = 1ULL << 32;
179 
180 	/*
181 	 * Limit coherent and dma mask based on size and default mask
182 	 * set by the driver.
183 	 */
184 	end = dma_start + size - 1;
185 	mask = DMA_BIT_MASK(ilog2(end) + 1);
186 	dev->coherent_dma_mask &= mask;
187 	*dev->dma_mask &= mask;
188 	/* ...but only set bus limit and range map if we found valid dma-ranges earlier */
189 	if (!ret) {
190 		dev->bus_dma_limit = end;
191 		dev->dma_range_map = map;
192 	}
193 
194 	coherent = of_dma_is_coherent(np);
195 	dev_dbg(dev, "device is%sdma coherent\n",
196 		coherent ? " " : " not ");
197 
198 	iommu = of_iommu_configure(dev, np, id);
199 	if (PTR_ERR(iommu) == -EPROBE_DEFER) {
200 		/* Don't touch range map if it wasn't set from a valid dma-ranges */
201 		if (!ret)
202 			dev->dma_range_map = NULL;
203 		kfree(map);
204 		return -EPROBE_DEFER;
205 	}
206 
207 	dev_dbg(dev, "device is%sbehind an iommu\n",
208 		iommu ? " " : " not ");
209 
210 	arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
211 
212 	if (!iommu)
213 		of_dma_set_restricted_buffer(dev, np);
214 
215 	return 0;
216 }
217 EXPORT_SYMBOL_GPL(of_dma_configure_id);
218 
of_device_register(struct platform_device * pdev)219 int of_device_register(struct platform_device *pdev)
220 {
221 	device_initialize(&pdev->dev);
222 	return of_device_add(pdev);
223 }
224 EXPORT_SYMBOL(of_device_register);
225 
of_device_unregister(struct platform_device * ofdev)226 void of_device_unregister(struct platform_device *ofdev)
227 {
228 	device_unregister(&ofdev->dev);
229 }
230 EXPORT_SYMBOL(of_device_unregister);
231 
of_device_get_match_data(const struct device * dev)232 const void *of_device_get_match_data(const struct device *dev)
233 {
234 	const struct of_device_id *match;
235 
236 	match = of_match_device(dev->driver->of_match_table, dev);
237 	if (!match)
238 		return NULL;
239 
240 	return match->data;
241 }
242 EXPORT_SYMBOL(of_device_get_match_data);
243 
of_device_get_modalias(struct device * dev,char * str,ssize_t len)244 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
245 {
246 	const char *compat;
247 	char *c;
248 	struct property *p;
249 	ssize_t csize;
250 	ssize_t tsize;
251 
252 	if ((!dev) || (!dev->of_node))
253 		return -ENODEV;
254 
255 	/* Name & Type */
256 	/* %p eats all alphanum characters, so %c must be used here */
257 	csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T',
258 			 of_node_get_device_type(dev->of_node));
259 	tsize = csize;
260 	len -= csize;
261 	if (str)
262 		str += csize;
263 
264 	of_property_for_each_string(dev->of_node, "compatible", p, compat) {
265 		csize = strlen(compat) + 1;
266 		tsize += csize;
267 		if (csize > len)
268 			continue;
269 
270 		csize = snprintf(str, len, "C%s", compat);
271 		for (c = str; c; ) {
272 			c = strchr(c, ' ');
273 			if (c)
274 				*c++ = '_';
275 		}
276 		len -= csize;
277 		str += csize;
278 	}
279 
280 	return tsize;
281 }
282 
of_device_request_module(struct device * dev)283 int of_device_request_module(struct device *dev)
284 {
285 	char *str;
286 	ssize_t size;
287 	int ret;
288 
289 	size = of_device_get_modalias(dev, NULL, 0);
290 	if (size < 0)
291 		return size;
292 
293 	str = kmalloc(size + 1, GFP_KERNEL);
294 	if (!str)
295 		return -ENOMEM;
296 
297 	of_device_get_modalias(dev, str, size);
298 	str[size] = '\0';
299 	ret = request_module(str);
300 	kfree(str);
301 
302 	return ret;
303 }
304 EXPORT_SYMBOL_GPL(of_device_request_module);
305 
306 /**
307  * of_device_modalias - Fill buffer with newline terminated modalias string
308  * @dev:	Calling device
309  * @str:	Modalias string
310  * @len:	Size of @str
311  */
of_device_modalias(struct device * dev,char * str,ssize_t len)312 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
313 {
314 	ssize_t sl = of_device_get_modalias(dev, str, len - 2);
315 	if (sl < 0)
316 		return sl;
317 	if (sl > len - 2)
318 		return -ENOMEM;
319 
320 	str[sl++] = '\n';
321 	str[sl] = 0;
322 	return sl;
323 }
324 EXPORT_SYMBOL_GPL(of_device_modalias);
325 
326 /**
327  * of_device_uevent - Display OF related uevent information
328  * @dev:	Device to apply DMA configuration
329  * @env:	Kernel object's userspace event reference
330  */
of_device_uevent(struct device * dev,struct kobj_uevent_env * env)331 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
332 {
333 	const char *compat, *type;
334 	struct alias_prop *app;
335 	struct property *p;
336 	int seen = 0;
337 
338 	if ((!dev) || (!dev->of_node))
339 		return;
340 
341 	add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);
342 	add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
343 	type = of_node_get_device_type(dev->of_node);
344 	if (type)
345 		add_uevent_var(env, "OF_TYPE=%s", type);
346 
347 	/* Since the compatible field can contain pretty much anything
348 	 * it's not really legal to split it out with commas. We split it
349 	 * up using a number of environment variables instead. */
350 	of_property_for_each_string(dev->of_node, "compatible", p, compat) {
351 		add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
352 		seen++;
353 	}
354 	add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
355 
356 	seen = 0;
357 	mutex_lock(&of_mutex);
358 	list_for_each_entry(app, &aliases_lookup, link) {
359 		if (dev->of_node == app->np) {
360 			add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
361 				       app->alias);
362 			seen++;
363 		}
364 	}
365 	mutex_unlock(&of_mutex);
366 }
367 
of_device_uevent_modalias(struct device * dev,struct kobj_uevent_env * env)368 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
369 {
370 	int sl;
371 
372 	if ((!dev) || (!dev->of_node))
373 		return -ENODEV;
374 
375 	/* Devicetree modalias is tricky, we add it in 2 steps */
376 	if (add_uevent_var(env, "MODALIAS="))
377 		return -ENOMEM;
378 
379 	sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
380 				    sizeof(env->buf) - env->buflen);
381 	if (sl >= (sizeof(env->buf) - env->buflen))
382 		return -ENOMEM;
383 	env->buflen += sl;
384 
385 	return 0;
386 }
387 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);
388