xref: /openbmc/linux/drivers/pnp/manager.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * manager.c - Resource Management, Conflict Resolution, Activation and Disabling of Devices
4  *
5  * based on isapnp.c resource management (c) Jaroslav Kysela <perex@perex.cz>
6  * Copyright 2003 Adam Belay <ambx1@neo.rr.com>
7  * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
8  *	Bjorn Helgaas <bjorn.helgaas@hp.com>
9  */
10 
11 #include <linux/errno.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/pnp.h>
16 #include <linux/bitmap.h>
17 #include <linux/mutex.h>
18 #include "base.h"
19 
20 DEFINE_MUTEX(pnp_res_mutex);
21 
22 static struct resource *pnp_find_resource(struct pnp_dev *dev,
23 					  unsigned char rule,
24 					  unsigned long type,
25 					  unsigned int bar)
26 {
27 	struct resource *res = pnp_get_resource(dev, type, bar);
28 
29 	/* when the resource already exists, set its resource bits from rule */
30 	if (res) {
31 		res->flags &= ~IORESOURCE_BITS;
32 		res->flags |= rule & IORESOURCE_BITS;
33 	}
34 
35 	return res;
36 }
37 
38 static int pnp_assign_port(struct pnp_dev *dev, struct pnp_port *rule, int idx)
39 {
40 	struct resource *res, local_res;
41 
42 	res = pnp_find_resource(dev, rule->flags, IORESOURCE_IO, idx);
43 	if (res) {
44 		pnp_dbg(&dev->dev, "  io %d already set to %#llx-%#llx "
45 			"flags %#lx\n", idx, (unsigned long long) res->start,
46 			(unsigned long long) res->end, res->flags);
47 		return 0;
48 	}
49 
50 	res = &local_res;
51 	res->flags = rule->flags | IORESOURCE_AUTO;
52 	res->start = 0;
53 	res->end = 0;
54 
55 	if (!rule->size) {
56 		res->flags |= IORESOURCE_DISABLED;
57 		pnp_dbg(&dev->dev, "  io %d disabled\n", idx);
58 		goto __add;
59 	}
60 
61 	res->start = rule->min;
62 	res->end = res->start + rule->size - 1;
63 
64 	while (!pnp_check_port(dev, res)) {
65 		res->start += rule->align;
66 		res->end = res->start + rule->size - 1;
67 		if (res->start > rule->max || !rule->align) {
68 			pnp_dbg(&dev->dev, "  couldn't assign io %d "
69 				"(min %#llx max %#llx)\n", idx,
70 				(unsigned long long) rule->min,
71 				(unsigned long long) rule->max);
72 			return -EBUSY;
73 		}
74 	}
75 
76 __add:
77 	pnp_add_io_resource(dev, res->start, res->end, res->flags);
78 	return 0;
79 }
80 
81 static int pnp_assign_mem(struct pnp_dev *dev, struct pnp_mem *rule, int idx)
82 {
83 	struct resource *res, local_res;
84 
85 	res = pnp_find_resource(dev, rule->flags, IORESOURCE_MEM, idx);
86 	if (res) {
87 		pnp_dbg(&dev->dev, "  mem %d already set to %#llx-%#llx "
88 			"flags %#lx\n", idx, (unsigned long long) res->start,
89 			(unsigned long long) res->end, res->flags);
90 		return 0;
91 	}
92 
93 	res = &local_res;
94 	res->flags = rule->flags | IORESOURCE_AUTO;
95 	res->start = 0;
96 	res->end = 0;
97 
98 	/* ??? rule->flags restricted to 8 bits, all tests bogus ??? */
99 	if (!(rule->flags & IORESOURCE_MEM_WRITEABLE))
100 		res->flags |= IORESOURCE_READONLY;
101 	if (rule->flags & IORESOURCE_MEM_RANGELENGTH)
102 		res->flags |= IORESOURCE_RANGELENGTH;
103 	if (rule->flags & IORESOURCE_MEM_SHADOWABLE)
104 		res->flags |= IORESOURCE_SHADOWABLE;
105 
106 	if (!rule->size) {
107 		res->flags |= IORESOURCE_DISABLED;
108 		pnp_dbg(&dev->dev, "  mem %d disabled\n", idx);
109 		goto __add;
110 	}
111 
112 	res->start = rule->min;
113 	res->end = res->start + rule->size - 1;
114 
115 	while (!pnp_check_mem(dev, res)) {
116 		res->start += rule->align;
117 		res->end = res->start + rule->size - 1;
118 		if (res->start > rule->max || !rule->align) {
119 			pnp_dbg(&dev->dev, "  couldn't assign mem %d "
120 				"(min %#llx max %#llx)\n", idx,
121 				(unsigned long long) rule->min,
122 				(unsigned long long) rule->max);
123 			return -EBUSY;
124 		}
125 	}
126 
127 __add:
128 	pnp_add_mem_resource(dev, res->start, res->end, res->flags);
129 	return 0;
130 }
131 
132 static int pnp_assign_irq(struct pnp_dev *dev, struct pnp_irq *rule, int idx)
133 {
134 	struct resource *res, local_res;
135 	int i;
136 
137 	/* IRQ priority: this table is good for i386 */
138 	static unsigned short xtab[16] = {
139 		5, 10, 11, 12, 9, 14, 15, 7, 3, 4, 13, 0, 1, 6, 8, 2
140 	};
141 
142 	res = pnp_find_resource(dev, rule->flags, IORESOURCE_IRQ, idx);
143 	if (res) {
144 		pnp_dbg(&dev->dev, "  irq %d already set to %d flags %#lx\n",
145 			idx, (int) res->start, res->flags);
146 		return 0;
147 	}
148 
149 	res = &local_res;
150 	res->flags = rule->flags | IORESOURCE_AUTO;
151 	res->start = -1;
152 	res->end = -1;
153 
154 	if (bitmap_empty(rule->map.bits, PNP_IRQ_NR)) {
155 		res->flags |= IORESOURCE_DISABLED;
156 		pnp_dbg(&dev->dev, "  irq %d disabled\n", idx);
157 		goto __add;
158 	}
159 
160 	/* TBD: need check for >16 IRQ */
161 	res->start = find_next_bit(rule->map.bits, PNP_IRQ_NR, 16);
162 	if (res->start < PNP_IRQ_NR) {
163 		res->end = res->start;
164 		goto __add;
165 	}
166 	for (i = 0; i < 16; i++) {
167 		if (test_bit(xtab[i], rule->map.bits)) {
168 			res->start = res->end = xtab[i];
169 			if (pnp_check_irq(dev, res))
170 				goto __add;
171 		}
172 	}
173 
174 	if (rule->flags & IORESOURCE_IRQ_OPTIONAL) {
175 		res->start = -1;
176 		res->end = -1;
177 		res->flags |= IORESOURCE_DISABLED;
178 		pnp_dbg(&dev->dev, "  irq %d disabled (optional)\n", idx);
179 		goto __add;
180 	}
181 
182 	pnp_dbg(&dev->dev, "  couldn't assign irq %d\n", idx);
183 	return -EBUSY;
184 
185 __add:
186 	pnp_add_irq_resource(dev, res->start, res->flags);
187 	return 0;
188 }
189 
190 #ifdef CONFIG_ISA_DMA_API
191 static int pnp_assign_dma(struct pnp_dev *dev, struct pnp_dma *rule, int idx)
192 {
193 	struct resource *res, local_res;
194 	int i;
195 
196 	/* DMA priority: this table is good for i386 */
197 	static unsigned short xtab[8] = {
198 		1, 3, 5, 6, 7, 0, 2, 4
199 	};
200 
201 	res = pnp_find_resource(dev, rule->flags, IORESOURCE_DMA, idx);
202 	if (res) {
203 		pnp_dbg(&dev->dev, "  dma %d already set to %d flags %#lx\n",
204 			idx, (int) res->start, res->flags);
205 		return 0;
206 	}
207 
208 	res = &local_res;
209 	res->flags = rule->flags | IORESOURCE_AUTO;
210 	res->start = -1;
211 	res->end = -1;
212 
213 	if (!rule->map) {
214 		res->flags |= IORESOURCE_DISABLED;
215 		pnp_dbg(&dev->dev, "  dma %d disabled\n", idx);
216 		goto __add;
217 	}
218 
219 	for (i = 0; i < 8; i++) {
220 		if (rule->map & (1 << xtab[i])) {
221 			res->start = res->end = xtab[i];
222 			if (pnp_check_dma(dev, res))
223 				goto __add;
224 		}
225 	}
226 
227 	pnp_dbg(&dev->dev, "  couldn't assign dma %d\n", idx);
228 	return -EBUSY;
229 
230 __add:
231 	pnp_add_dma_resource(dev, res->start, res->flags);
232 	return 0;
233 }
234 #endif /* CONFIG_ISA_DMA_API */
235 
236 void pnp_init_resources(struct pnp_dev *dev)
237 {
238 	pnp_free_resources(dev);
239 }
240 
241 static void pnp_clean_resource_table(struct pnp_dev *dev)
242 {
243 	struct pnp_resource *pnp_res, *tmp;
244 
245 	list_for_each_entry_safe(pnp_res, tmp, &dev->resources, list) {
246 		if (pnp_res->res.flags & IORESOURCE_AUTO)
247 			pnp_free_resource(pnp_res);
248 	}
249 }
250 
251 /**
252  * pnp_assign_resources - assigns resources to the device based on the specified dependent number
253  * @dev: pointer to the desired device
254  * @set: the dependent function number
255  */
256 static int pnp_assign_resources(struct pnp_dev *dev, int set)
257 {
258 	struct pnp_option *option;
259 	int nport = 0, nmem = 0, nirq = 0;
260 	int ndma __maybe_unused = 0;
261 	int ret = 0;
262 
263 	pnp_dbg(&dev->dev, "pnp_assign_resources, try dependent set %d\n", set);
264 	mutex_lock(&pnp_res_mutex);
265 	pnp_clean_resource_table(dev);
266 
267 	list_for_each_entry(option, &dev->options, list) {
268 		if (pnp_option_is_dependent(option) &&
269 		    pnp_option_set(option) != set)
270 				continue;
271 
272 		switch (option->type) {
273 		case IORESOURCE_IO:
274 			ret = pnp_assign_port(dev, &option->u.port, nport++);
275 			break;
276 		case IORESOURCE_MEM:
277 			ret = pnp_assign_mem(dev, &option->u.mem, nmem++);
278 			break;
279 		case IORESOURCE_IRQ:
280 			ret = pnp_assign_irq(dev, &option->u.irq, nirq++);
281 			break;
282 #ifdef CONFIG_ISA_DMA_API
283 		case IORESOURCE_DMA:
284 			ret = pnp_assign_dma(dev, &option->u.dma, ndma++);
285 			break;
286 #endif
287 		default:
288 			ret = -EINVAL;
289 			break;
290 		}
291 		if (ret < 0)
292 			break;
293 	}
294 
295 	mutex_unlock(&pnp_res_mutex);
296 	if (ret < 0) {
297 		pnp_dbg(&dev->dev, "pnp_assign_resources failed (%d)\n", ret);
298 		pnp_clean_resource_table(dev);
299 	} else
300 		dbg_pnp_show_resources(dev, "pnp_assign_resources succeeded");
301 	return ret;
302 }
303 
304 /**
305  * pnp_auto_config_dev - automatically assigns resources to a device
306  * @dev: pointer to the desired device
307  */
308 int pnp_auto_config_dev(struct pnp_dev *dev)
309 {
310 	int i, ret;
311 
312 	if (!pnp_can_configure(dev)) {
313 		pnp_dbg(&dev->dev, "configuration not supported\n");
314 		return -ENODEV;
315 	}
316 
317 	ret = pnp_assign_resources(dev, 0);
318 	if (ret == 0)
319 		return 0;
320 
321 	for (i = 1; i < dev->num_dependent_sets; i++) {
322 		ret = pnp_assign_resources(dev, i);
323 		if (ret == 0)
324 			return 0;
325 	}
326 
327 	dev_err(&dev->dev, "unable to assign resources\n");
328 	return ret;
329 }
330 
331 /**
332  * pnp_start_dev - low-level start of the PnP device
333  * @dev: pointer to the desired device
334  *
335  * assumes that resources have already been allocated
336  */
337 int pnp_start_dev(struct pnp_dev *dev)
338 {
339 	if (!pnp_can_write(dev)) {
340 		pnp_dbg(&dev->dev, "activation not supported\n");
341 		return -EINVAL;
342 	}
343 
344 	dbg_pnp_show_resources(dev, "pnp_start_dev");
345 	if (dev->protocol->set(dev) < 0) {
346 		dev_err(&dev->dev, "activation failed\n");
347 		return -EIO;
348 	}
349 
350 	dev_info(&dev->dev, "activated\n");
351 	return 0;
352 }
353 
354 /**
355  * pnp_stop_dev - low-level disable of the PnP device
356  * @dev: pointer to the desired device
357  *
358  * does not free resources
359  */
360 int pnp_stop_dev(struct pnp_dev *dev)
361 {
362 	if (!pnp_can_disable(dev)) {
363 		pnp_dbg(&dev->dev, "disabling not supported\n");
364 		return -EINVAL;
365 	}
366 	if (dev->protocol->disable(dev) < 0) {
367 		dev_err(&dev->dev, "disable failed\n");
368 		return -EIO;
369 	}
370 
371 	dev_info(&dev->dev, "disabled\n");
372 	return 0;
373 }
374 
375 /**
376  * pnp_activate_dev - activates a PnP device for use
377  * @dev: pointer to the desired device
378  *
379  * does not validate or set resources so be careful.
380  */
381 int pnp_activate_dev(struct pnp_dev *dev)
382 {
383 	int error;
384 
385 	if (dev->active)
386 		return 0;
387 
388 	/* ensure resources are allocated */
389 	if (pnp_auto_config_dev(dev))
390 		return -EBUSY;
391 
392 	error = pnp_start_dev(dev);
393 	if (error)
394 		return error;
395 
396 	dev->active = 1;
397 	return 0;
398 }
399 
400 /**
401  * pnp_disable_dev - disables device
402  * @dev: pointer to the desired device
403  *
404  * inform the correct pnp protocol so that resources can be used by other devices
405  */
406 int pnp_disable_dev(struct pnp_dev *dev)
407 {
408 	int error;
409 
410 	if (!dev->active)
411 		return 0;
412 
413 	error = pnp_stop_dev(dev);
414 	if (error)
415 		return error;
416 
417 	dev->active = 0;
418 
419 	/* release the resources so that other devices can use them */
420 	mutex_lock(&pnp_res_mutex);
421 	pnp_clean_resource_table(dev);
422 	mutex_unlock(&pnp_res_mutex);
423 
424 	return 0;
425 }
426 
427 EXPORT_SYMBOL(pnp_start_dev);
428 EXPORT_SYMBOL(pnp_stop_dev);
429 EXPORT_SYMBOL(pnp_activate_dev);
430 EXPORT_SYMBOL(pnp_disable_dev);
431