1 /*
2  * Shared interrupt handling code for IPR and INTC2 types of IRQs.
3  *
4  * Copyright (C) 2007, 2008 Magnus Damm
5  * Copyright (C) 2009 - 2012 Paul Mundt
6  *
7  * Based on intc2.c and ipr.c
8  *
9  * Copyright (C) 1999  Niibe Yutaka & Takeshi Yaegashi
10  * Copyright (C) 2000  Kazumoto Kojima
11  * Copyright (C) 2001  David J. Mckay (david.mckay@st.com)
12  * Copyright (C) 2003  Takashi Kusuda <kusuda-takashi@hitachi-ul.co.jp>
13  * Copyright (C) 2005, 2006  Paul Mundt
14  *
15  * This file is subject to the terms and conditions of the GNU General Public
16  * License.  See the file "COPYING" in the main directory of this archive
17  * for more details.
18  */
19 #define pr_fmt(fmt) "intc: " fmt
20 
21 #include <linux/init.h>
22 #include <linux/irq.h>
23 #include <linux/io.h>
24 #include <linux/slab.h>
25 #include <linux/stat.h>
26 #include <linux/interrupt.h>
27 #include <linux/sh_intc.h>
28 #include <linux/irqdomain.h>
29 #include <linux/device.h>
30 #include <linux/syscore_ops.h>
31 #include <linux/list.h>
32 #include <linux/spinlock.h>
33 #include <linux/radix-tree.h>
34 #include <linux/export.h>
35 #include <linux/sort.h>
36 #include "internals.h"
37 
38 LIST_HEAD(intc_list);
39 DEFINE_RAW_SPINLOCK(intc_big_lock);
40 static unsigned int nr_intc_controllers;
41 
42 /*
43  * Default priority level
44  * - this needs to be at least 2 for 5-bit priorities on 7780
45  */
46 static unsigned int default_prio_level = 2;	/* 2 - 16 */
47 static unsigned int intc_prio_level[INTC_NR_IRQS];	/* for now */
48 
intc_get_dfl_prio_level(void)49 unsigned int intc_get_dfl_prio_level(void)
50 {
51 	return default_prio_level;
52 }
53 
intc_get_prio_level(unsigned int irq)54 unsigned int intc_get_prio_level(unsigned int irq)
55 {
56 	return intc_prio_level[irq];
57 }
58 
intc_set_prio_level(unsigned int irq,unsigned int level)59 void intc_set_prio_level(unsigned int irq, unsigned int level)
60 {
61 	unsigned long flags;
62 
63 	raw_spin_lock_irqsave(&intc_big_lock, flags);
64 	intc_prio_level[irq] = level;
65 	raw_spin_unlock_irqrestore(&intc_big_lock, flags);
66 }
67 
intc_redirect_irq(struct irq_desc * desc)68 static void intc_redirect_irq(struct irq_desc *desc)
69 {
70 	generic_handle_irq((unsigned int)irq_desc_get_handler_data(desc));
71 }
72 
intc_register_irq(struct intc_desc * desc,struct intc_desc_int * d,intc_enum enum_id,unsigned int irq)73 static void __init intc_register_irq(struct intc_desc *desc,
74 				     struct intc_desc_int *d,
75 				     intc_enum enum_id,
76 				     unsigned int irq)
77 {
78 	struct intc_handle_int *hp;
79 	struct irq_data *irq_data;
80 	unsigned int data[2], primary;
81 	unsigned long flags;
82 
83 	raw_spin_lock_irqsave(&intc_big_lock, flags);
84 	radix_tree_insert(&d->tree, enum_id, intc_irq_xlate_get(irq));
85 	raw_spin_unlock_irqrestore(&intc_big_lock, flags);
86 
87 	/*
88 	 * Prefer single interrupt source bitmap over other combinations:
89 	 *
90 	 * 1. bitmap, single interrupt source
91 	 * 2. priority, single interrupt source
92 	 * 3. bitmap, multiple interrupt sources (groups)
93 	 * 4. priority, multiple interrupt sources (groups)
94 	 */
95 	data[0] = intc_get_mask_handle(desc, d, enum_id, 0);
96 	data[1] = intc_get_prio_handle(desc, d, enum_id, 0);
97 
98 	primary = 0;
99 	if (!data[0] && data[1])
100 		primary = 1;
101 
102 	if (!data[0] && !data[1])
103 		pr_warn("missing unique irq mask for irq %d (vect 0x%04x)\n",
104 			irq, irq2evt(irq));
105 
106 	data[0] = data[0] ? data[0] : intc_get_mask_handle(desc, d, enum_id, 1);
107 	data[1] = data[1] ? data[1] : intc_get_prio_handle(desc, d, enum_id, 1);
108 
109 	if (!data[primary])
110 		primary ^= 1;
111 
112 	BUG_ON(!data[primary]); /* must have primary masking method */
113 
114 	irq_data = irq_get_irq_data(irq);
115 
116 	disable_irq_nosync(irq);
117 	irq_set_chip_and_handler_name(irq, &d->chip, handle_level_irq,
118 				      "level");
119 	irq_set_chip_data(irq, (void *)data[primary]);
120 
121 	/*
122 	 * set priority level
123 	 */
124 	intc_set_prio_level(irq, intc_get_dfl_prio_level());
125 
126 	/* enable secondary masking method if present */
127 	if (data[!primary])
128 		_intc_enable(irq_data, data[!primary]);
129 
130 	/* add irq to d->prio list if priority is available */
131 	if (data[1]) {
132 		hp = d->prio + d->nr_prio;
133 		hp->irq = irq;
134 		hp->handle = data[1];
135 
136 		if (primary) {
137 			/*
138 			 * only secondary priority should access registers, so
139 			 * set _INTC_FN(h) = REG_FN_ERR for intc_set_priority()
140 			 */
141 			hp->handle &= ~_INTC_MK(0x0f, 0, 0, 0, 0, 0);
142 			hp->handle |= _INTC_MK(REG_FN_ERR, 0, 0, 0, 0, 0);
143 		}
144 		d->nr_prio++;
145 	}
146 
147 	/* add irq to d->sense list if sense is available */
148 	data[0] = intc_get_sense_handle(desc, d, enum_id);
149 	if (data[0]) {
150 		(d->sense + d->nr_sense)->irq = irq;
151 		(d->sense + d->nr_sense)->handle = data[0];
152 		d->nr_sense++;
153 	}
154 
155 	/* irq should be disabled by default */
156 	d->chip.irq_mask(irq_data);
157 
158 	intc_set_ack_handle(irq, desc, d, enum_id);
159 	intc_set_dist_handle(irq, desc, d, enum_id);
160 
161 	activate_irq(irq);
162 }
163 
save_reg(struct intc_desc_int * d,unsigned int cnt,unsigned long value,unsigned int smp)164 static unsigned int __init save_reg(struct intc_desc_int *d,
165 				    unsigned int cnt,
166 				    unsigned long value,
167 				    unsigned int smp)
168 {
169 	if (value) {
170 		value = intc_phys_to_virt(d, value);
171 
172 		d->reg[cnt] = value;
173 #ifdef CONFIG_SMP
174 		d->smp[cnt] = smp;
175 #endif
176 		return 1;
177 	}
178 
179 	return 0;
180 }
181 
intc_map(struct irq_domain * domain,int irq)182 static bool __init intc_map(struct irq_domain *domain, int irq)
183 {
184 	if (!irq_to_desc(irq) && irq_alloc_desc_at(irq, NUMA_NO_NODE) != irq) {
185 		pr_err("uname to allocate IRQ %d\n", irq);
186 		return false;
187 	}
188 
189 	if (irq_domain_associate(domain, irq, irq)) {
190 		pr_err("domain association failure\n");
191 		return false;
192 	}
193 
194 	return true;
195 }
196 
register_intc_controller(struct intc_desc * desc)197 int __init register_intc_controller(struct intc_desc *desc)
198 {
199 	unsigned int i, k, smp;
200 	struct intc_hw_desc *hw = &desc->hw;
201 	struct intc_desc_int *d;
202 	struct resource *res;
203 
204 	pr_info("Registered controller '%s' with %u IRQs\n",
205 		desc->name, hw->nr_vectors);
206 
207 	d = kzalloc(sizeof(*d), GFP_NOWAIT);
208 	if (!d)
209 		goto err0;
210 
211 	INIT_LIST_HEAD(&d->list);
212 	list_add_tail(&d->list, &intc_list);
213 
214 	raw_spin_lock_init(&d->lock);
215 	INIT_RADIX_TREE(&d->tree, GFP_ATOMIC);
216 
217 	d->index = nr_intc_controllers;
218 
219 	if (desc->num_resources) {
220 		d->nr_windows = desc->num_resources;
221 		d->window = kcalloc(d->nr_windows, sizeof(*d->window),
222 				    GFP_NOWAIT);
223 		if (!d->window)
224 			goto err1;
225 
226 		for (k = 0; k < d->nr_windows; k++) {
227 			res = desc->resource + k;
228 			WARN_ON(resource_type(res) != IORESOURCE_MEM);
229 			d->window[k].phys = res->start;
230 			d->window[k].size = resource_size(res);
231 			d->window[k].virt = ioremap(res->start,
232 						    resource_size(res));
233 			if (!d->window[k].virt)
234 				goto err2;
235 		}
236 	}
237 
238 	d->nr_reg = hw->mask_regs ? hw->nr_mask_regs * 2 : 0;
239 #ifdef CONFIG_INTC_BALANCING
240 	if (d->nr_reg)
241 		d->nr_reg += hw->nr_mask_regs;
242 #endif
243 	d->nr_reg += hw->prio_regs ? hw->nr_prio_regs * 2 : 0;
244 	d->nr_reg += hw->sense_regs ? hw->nr_sense_regs : 0;
245 	d->nr_reg += hw->ack_regs ? hw->nr_ack_regs : 0;
246 	d->nr_reg += hw->subgroups ? hw->nr_subgroups : 0;
247 
248 	d->reg = kcalloc(d->nr_reg, sizeof(*d->reg), GFP_NOWAIT);
249 	if (!d->reg)
250 		goto err2;
251 
252 #ifdef CONFIG_SMP
253 	d->smp = kcalloc(d->nr_reg, sizeof(*d->smp), GFP_NOWAIT);
254 	if (!d->smp)
255 		goto err3;
256 #endif
257 	k = 0;
258 
259 	if (hw->mask_regs) {
260 		for (i = 0; i < hw->nr_mask_regs; i++) {
261 			smp = IS_SMP(hw->mask_regs[i]);
262 			k += save_reg(d, k, hw->mask_regs[i].set_reg, smp);
263 			k += save_reg(d, k, hw->mask_regs[i].clr_reg, smp);
264 #ifdef CONFIG_INTC_BALANCING
265 			k += save_reg(d, k, hw->mask_regs[i].dist_reg, 0);
266 #endif
267 		}
268 	}
269 
270 	if (hw->prio_regs) {
271 		d->prio = kcalloc(hw->nr_vectors, sizeof(*d->prio),
272 				  GFP_NOWAIT);
273 		if (!d->prio)
274 			goto err4;
275 
276 		for (i = 0; i < hw->nr_prio_regs; i++) {
277 			smp = IS_SMP(hw->prio_regs[i]);
278 			k += save_reg(d, k, hw->prio_regs[i].set_reg, smp);
279 			k += save_reg(d, k, hw->prio_regs[i].clr_reg, smp);
280 		}
281 
282 		sort(d->prio, hw->nr_prio_regs, sizeof(*d->prio),
283 		     intc_handle_int_cmp, NULL);
284 	}
285 
286 	if (hw->sense_regs) {
287 		d->sense = kcalloc(hw->nr_vectors, sizeof(*d->sense),
288 				   GFP_NOWAIT);
289 		if (!d->sense)
290 			goto err5;
291 
292 		for (i = 0; i < hw->nr_sense_regs; i++)
293 			k += save_reg(d, k, hw->sense_regs[i].reg, 0);
294 
295 		sort(d->sense, hw->nr_sense_regs, sizeof(*d->sense),
296 		     intc_handle_int_cmp, NULL);
297 	}
298 
299 	if (hw->subgroups)
300 		for (i = 0; i < hw->nr_subgroups; i++)
301 			if (hw->subgroups[i].reg)
302 				k+= save_reg(d, k, hw->subgroups[i].reg, 0);
303 
304 	memcpy(&d->chip, &intc_irq_chip, sizeof(struct irq_chip));
305 	d->chip.name = desc->name;
306 
307 	if (hw->ack_regs)
308 		for (i = 0; i < hw->nr_ack_regs; i++)
309 			k += save_reg(d, k, hw->ack_regs[i].set_reg, 0);
310 	else
311 		d->chip.irq_mask_ack = d->chip.irq_disable;
312 
313 	/* disable bits matching force_disable before registering irqs */
314 	if (desc->force_disable)
315 		intc_enable_disable_enum(desc, d, desc->force_disable, 0);
316 
317 	/* disable bits matching force_enable before registering irqs */
318 	if (desc->force_enable)
319 		intc_enable_disable_enum(desc, d, desc->force_enable, 0);
320 
321 	BUG_ON(k > 256); /* _INTC_ADDR_E() and _INTC_ADDR_D() are 8 bits */
322 
323 	intc_irq_domain_init(d, hw);
324 
325 	/* register the vectors one by one */
326 	for (i = 0; i < hw->nr_vectors; i++) {
327 		struct intc_vect *vect = hw->vectors + i;
328 		unsigned int irq = evt2irq(vect->vect);
329 
330 		if (!vect->enum_id)
331 			continue;
332 
333 		if (!intc_map(d->domain, irq))
334 			continue;
335 
336 		intc_irq_xlate_set(irq, vect->enum_id, d);
337 		intc_register_irq(desc, d, vect->enum_id, irq);
338 
339 		for (k = i + 1; k < hw->nr_vectors; k++) {
340 			struct intc_vect *vect2 = hw->vectors + k;
341 			unsigned int irq2 = evt2irq(vect2->vect);
342 
343 			if (vect->enum_id != vect2->enum_id)
344 				continue;
345 
346 			/*
347 			 * In the case of multi-evt handling and sparse
348 			 * IRQ support, each vector still needs to have
349 			 * its own backing irq_desc.
350 			 */
351 			if (!intc_map(d->domain, irq2))
352 				continue;
353 
354 			vect2->enum_id = 0;
355 
356 			/* redirect this interrupts to the first one */
357 			irq_set_chip(irq2, &dummy_irq_chip);
358 			irq_set_chained_handler_and_data(irq2,
359 							 intc_redirect_irq,
360 							 (void *)irq);
361 		}
362 	}
363 
364 	intc_subgroup_init(desc, d);
365 
366 	/* enable bits matching force_enable after registering irqs */
367 	if (desc->force_enable)
368 		intc_enable_disable_enum(desc, d, desc->force_enable, 1);
369 
370 	d->skip_suspend = desc->skip_syscore_suspend;
371 
372 	nr_intc_controllers++;
373 
374 	return 0;
375 err5:
376 	kfree(d->prio);
377 err4:
378 #ifdef CONFIG_SMP
379 	kfree(d->smp);
380 err3:
381 #endif
382 	kfree(d->reg);
383 err2:
384 	for (k = 0; k < d->nr_windows; k++)
385 		if (d->window[k].virt)
386 			iounmap(d->window[k].virt);
387 
388 	kfree(d->window);
389 err1:
390 	kfree(d);
391 err0:
392 	pr_err("unable to allocate INTC memory\n");
393 
394 	return -ENOMEM;
395 }
396 
intc_suspend(void)397 static int intc_suspend(void)
398 {
399 	struct intc_desc_int *d;
400 
401 	list_for_each_entry(d, &intc_list, list) {
402 		int irq;
403 
404 		if (d->skip_suspend)
405 			continue;
406 
407 		/* enable wakeup irqs belonging to this intc controller */
408 		for_each_active_irq(irq) {
409 			struct irq_data *data;
410 			struct irq_chip *chip;
411 
412 			data = irq_get_irq_data(irq);
413 			chip = irq_data_get_irq_chip(data);
414 			if (chip != &d->chip)
415 				continue;
416 			if (irqd_is_wakeup_set(data))
417 				chip->irq_enable(data);
418 		}
419 	}
420 	return 0;
421 }
422 
intc_resume(void)423 static void intc_resume(void)
424 {
425 	struct intc_desc_int *d;
426 
427 	list_for_each_entry(d, &intc_list, list) {
428 		int irq;
429 
430 		if (d->skip_suspend)
431 			continue;
432 
433 		for_each_active_irq(irq) {
434 			struct irq_data *data;
435 			struct irq_chip *chip;
436 
437 			data = irq_get_irq_data(irq);
438 			chip = irq_data_get_irq_chip(data);
439 			/*
440 			 * This will catch the redirect and VIRQ cases
441 			 * due to the dummy_irq_chip being inserted.
442 			 */
443 			if (chip != &d->chip)
444 				continue;
445 			if (irqd_irq_disabled(data))
446 				chip->irq_disable(data);
447 			else
448 				chip->irq_enable(data);
449 		}
450 	}
451 }
452 
453 struct syscore_ops intc_syscore_ops = {
454 	.suspend	= intc_suspend,
455 	.resume		= intc_resume,
456 };
457 
458 struct bus_type intc_subsys = {
459 	.name		= "intc",
460 	.dev_name	= "intc",
461 };
462 
463 static ssize_t
show_intc_name(struct device * dev,struct device_attribute * attr,char * buf)464 show_intc_name(struct device *dev, struct device_attribute *attr, char *buf)
465 {
466 	struct intc_desc_int *d;
467 
468 	d = container_of(dev, struct intc_desc_int, dev);
469 
470 	return sprintf(buf, "%s\n", d->chip.name);
471 }
472 
473 static DEVICE_ATTR(name, S_IRUGO, show_intc_name, NULL);
474 
register_intc_devs(void)475 static int __init register_intc_devs(void)
476 {
477 	struct intc_desc_int *d;
478 	int error;
479 
480 	register_syscore_ops(&intc_syscore_ops);
481 
482 	error = subsys_system_register(&intc_subsys, NULL);
483 	if (!error) {
484 		list_for_each_entry(d, &intc_list, list) {
485 			d->dev.id = d->index;
486 			d->dev.bus = &intc_subsys;
487 			error = device_register(&d->dev);
488 			if (error == 0)
489 				error = device_create_file(&d->dev,
490 							   &dev_attr_name);
491 			if (error)
492 				break;
493 		}
494 	}
495 
496 	if (error)
497 		pr_err("device registration error\n");
498 
499 	return error;
500 }
501 device_initcall(register_intc_devs);
502