1 /*
2  * SS1000/SC2000 interrupt handling.
3  *
4  *  Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
5  *  Heavily based on arch/sparc/kernel/irq.c.
6  */
7 
8 #include <linux/kernel_stat.h>
9 #include <linux/seq_file.h>
10 
11 #include <asm/timer.h>
12 #include <asm/traps.h>
13 #include <asm/irq.h>
14 #include <asm/io.h>
15 #include <asm/sbi.h>
16 #include <asm/cacheflush.h>
17 
18 #include "kernel.h"
19 #include "irq.h"
20 
21 /* Sun4d interrupts fall roughly into two categories.  SBUS and
22  * cpu local.  CPU local interrupts cover the timer interrupts
23  * and whatnot, and we encode those as normal PILs between
24  * 0 and 15.
25  *
26  * SBUS interrupts are encoded integers including the board number
27  * (plus one), the SBUS level, and the SBUS slot number.  Sun4D
28  * IRQ dispatch is done by:
29  *
30  * 1) Reading the BW local interrupt table in order to get the bus
31  *    interrupt mask.
32  *
33  *    This table is indexed by SBUS interrupt level which can be
34  *    derived from the PIL we got interrupted on.
35  *
36  * 2) For each bus showing interrupt pending from #1, read the
37  *    SBI interrupt state register.  This will indicate which slots
38  *    have interrupts pending for that SBUS interrupt level.
39  */
40 
41 struct sun4d_timer_regs {
42 	u32	l10_timer_limit;
43 	u32	l10_cur_countx;
44 	u32	l10_limit_noclear;
45 	u32	ctrl;
46 	u32	l10_cur_count;
47 };
48 
49 static struct sun4d_timer_regs __iomem *sun4d_timers;
50 
51 #define TIMER_IRQ	10
52 
53 #define MAX_STATIC_ALLOC	4
54 static unsigned char sbus_tid[32];
55 
56 static struct irqaction *irq_action[NR_IRQS];
57 
58 static struct sbus_action {
59 	struct irqaction *action;
60 	/* For SMP this needs to be extended */
61 } *sbus_actions;
62 
63 static int pil_to_sbus[] = {
64 	0,
65 	0,
66 	1,
67 	2,
68 	0,
69 	3,
70 	0,
71 	4,
72 	0,
73 	5,
74 	0,
75 	6,
76 	0,
77 	7,
78 	0,
79 	0,
80 };
81 
82 static int sbus_to_pil[] = {
83 	0,
84 	2,
85 	3,
86 	5,
87 	7,
88 	9,
89 	11,
90 	13,
91 };
92 
93 static int nsbi;
94 
95 /* Exported for sun4d_smp.c */
96 DEFINE_SPINLOCK(sun4d_imsk_lock);
97 
show_sun4d_interrupts(struct seq_file * p,void * v)98 int show_sun4d_interrupts(struct seq_file *p, void *v)
99 {
100 	int i = *(loff_t *) v, j = 0, k = 0, sbusl;
101 	struct irqaction *action;
102 	unsigned long flags;
103 #ifdef CONFIG_SMP
104 	int x;
105 #endif
106 
107 	spin_lock_irqsave(&irq_action_lock, flags);
108 	if (i < NR_IRQS) {
109 		sbusl = pil_to_sbus[i];
110 		if (!sbusl) {
111 			action = *(i + irq_action);
112 			if (!action)
113 				goto out_unlock;
114 		} else {
115 			for (j = 0; j < nsbi; j++) {
116 				for (k = 0; k < 4; k++)
117 					action = sbus_actions[(j << 5) + (sbusl << 2) + k].action;
118 					if (action)
119 						goto found_it;
120 			}
121 			goto out_unlock;
122 		}
123 found_it:	seq_printf(p, "%3d: ", i);
124 #ifndef CONFIG_SMP
125 		seq_printf(p, "%10u ", kstat_irqs(i));
126 #else
127 		for_each_online_cpu(x)
128 			seq_printf(p, "%10u ",
129 			       kstat_cpu(cpu_logical_map(x)).irqs[i]);
130 #endif
131 		seq_printf(p, "%c %s",
132 			(action->flags & IRQF_DISABLED) ? '+' : ' ',
133 			action->name);
134 		action = action->next;
135 		for (;;) {
136 			for (; action; action = action->next) {
137 				seq_printf(p, ",%s %s",
138 					(action->flags & IRQF_DISABLED) ? " +" : "",
139 					action->name);
140 			}
141 			if (!sbusl)
142 				break;
143 			k++;
144 			if (k < 4) {
145 				action = sbus_actions[(j << 5) + (sbusl << 2) + k].action;
146 			} else {
147 				j++;
148 				if (j == nsbi)
149 					break;
150 				k = 0;
151 				action = sbus_actions[(j << 5) + (sbusl << 2)].action;
152 			}
153 		}
154 		seq_putc(p, '\n');
155 	}
156 out_unlock:
157 	spin_unlock_irqrestore(&irq_action_lock, flags);
158 	return 0;
159 }
160 
sun4d_free_irq(unsigned int irq,void * dev_id)161 void sun4d_free_irq(unsigned int irq, void *dev_id)
162 {
163 	struct irqaction *action, **actionp;
164 	struct irqaction *tmp = NULL;
165 	unsigned long flags;
166 
167 	spin_lock_irqsave(&irq_action_lock, flags);
168 	if (irq < 15)
169 		actionp = irq + irq_action;
170 	else
171 		actionp = &(sbus_actions[irq - (1 << 5)].action);
172 	action = *actionp;
173 	if (!action) {
174 		printk(KERN_ERR "Trying to free free IRQ%d\n", irq);
175 		goto out_unlock;
176 	}
177 	if (dev_id) {
178 		for (; action; action = action->next) {
179 			if (action->dev_id == dev_id)
180 				break;
181 			tmp = action;
182 		}
183 		if (!action) {
184 			printk(KERN_ERR "Trying to free free shared IRQ%d\n",
185 			       irq);
186 			goto out_unlock;
187 		}
188 	} else if (action->flags & IRQF_SHARED) {
189 		printk(KERN_ERR "Trying to free shared IRQ%d with NULL device ID\n",
190 		       irq);
191 		goto out_unlock;
192 	}
193 	if (action->flags & SA_STATIC_ALLOC) {
194 		/*
195 		 * This interrupt is marked as specially allocated
196 		 * so it is a bad idea to free it.
197 		 */
198 		printk(KERN_ERR "Attempt to free statically allocated IRQ%d (%s)\n",
199 		       irq, action->name);
200 		goto out_unlock;
201 	}
202 
203 	if (tmp)
204 		tmp->next = action->next;
205 	else
206 		*actionp = action->next;
207 
208 	spin_unlock_irqrestore(&irq_action_lock, flags);
209 
210 	synchronize_irq(irq);
211 
212 	spin_lock_irqsave(&irq_action_lock, flags);
213 
214 	kfree(action);
215 
216 	if (!(*actionp))
217 		__disable_irq(irq);
218 
219 out_unlock:
220 	spin_unlock_irqrestore(&irq_action_lock, flags);
221 }
222 
sun4d_handler_irq(int pil,struct pt_regs * regs)223 void sun4d_handler_irq(int pil, struct pt_regs *regs)
224 {
225 	struct pt_regs *old_regs;
226 	struct irqaction *action;
227 	int cpu = smp_processor_id();
228 	/* SBUS IRQ level (1 - 7) */
229 	int sbusl = pil_to_sbus[pil];
230 
231 	/* FIXME: Is this necessary?? */
232 	cc_get_ipen();
233 
234 	cc_set_iclr(1 << pil);
235 
236 	old_regs = set_irq_regs(regs);
237 	irq_enter();
238 	kstat_cpu(cpu).irqs[pil]++;
239 	if (!sbusl) {
240 		action = *(pil + irq_action);
241 		if (!action)
242 			unexpected_irq(pil, NULL, regs);
243 		do {
244 			action->handler(pil, action->dev_id);
245 			action = action->next;
246 		} while (action);
247 	} else {
248 		int bus_mask = bw_get_intr_mask(sbusl) & 0x3ffff;
249 		int sbino;
250 		struct sbus_action *actionp;
251 		unsigned mask, slot;
252 		int sbil = (sbusl << 2);
253 
254 		bw_clear_intr_mask(sbusl, bus_mask);
255 
256 		/* Loop for each pending SBI */
257 		for (sbino = 0; bus_mask; sbino++, bus_mask >>= 1)
258 			if (bus_mask & 1) {
259 				mask = acquire_sbi(SBI2DEVID(sbino), 0xf << sbil);
260 				mask &= (0xf << sbil);
261 				actionp = sbus_actions + (sbino << 5) + (sbil);
262 				/* Loop for each pending SBI slot */
263 				for (slot = (1 << sbil); mask; slot <<= 1, actionp++)
264 					if (mask & slot) {
265 						mask &= ~slot;
266 						action = actionp->action;
267 
268 						if (!action)
269 							unexpected_irq(pil, NULL, regs);
270 						do {
271 							action->handler(pil, action->dev_id);
272 							action = action->next;
273 						} while (action);
274 						release_sbi(SBI2DEVID(sbino), slot);
275 					}
276 			}
277 	}
278 	irq_exit();
279 	set_irq_regs(old_regs);
280 }
281 
sun4d_request_irq(unsigned int irq,irq_handler_t handler,unsigned long irqflags,const char * devname,void * dev_id)282 int sun4d_request_irq(unsigned int irq,
283 		irq_handler_t handler,
284 		unsigned long irqflags, const char *devname, void *dev_id)
285 {
286 	struct irqaction *action, *tmp = NULL, **actionp;
287 	unsigned long flags;
288 	int ret;
289 
290 	if (irq > 14 && irq < (1 << 5)) {
291 		ret = -EINVAL;
292 		goto out;
293 	}
294 
295 	if (!handler) {
296 		ret = -EINVAL;
297 		goto out;
298 	}
299 
300 	spin_lock_irqsave(&irq_action_lock, flags);
301 
302 	if (irq >= (1 << 5))
303 		actionp = &(sbus_actions[irq - (1 << 5)].action);
304 	else
305 		actionp = irq + irq_action;
306 	action = *actionp;
307 
308 	if (action) {
309 		if ((action->flags & IRQF_SHARED) && (irqflags & IRQF_SHARED)) {
310 			for (tmp = action; tmp->next; tmp = tmp->next)
311 				/* find last entry - tmp used below */;
312 		} else {
313 			ret = -EBUSY;
314 			goto out_unlock;
315 		}
316 		if ((action->flags & IRQF_DISABLED) ^ (irqflags & IRQF_DISABLED)) {
317 			printk(KERN_ERR "Attempt to mix fast and slow interrupts on IRQ%d denied\n",
318 			       irq);
319 			ret = -EBUSY;
320 			goto out_unlock;
321 		}
322 		action = NULL;		/* Or else! */
323 	}
324 
325 	/* If this is flagged as statically allocated then we use our
326 	 * private struct which is never freed.
327 	 */
328 	if (irqflags & SA_STATIC_ALLOC) {
329 		if (static_irq_count < MAX_STATIC_ALLOC)
330 			action = &static_irqaction[static_irq_count++];
331 		else
332 			printk(KERN_ERR "Request for IRQ%d (%s) SA_STATIC_ALLOC failed using kmalloc\n",
333 			       irq, devname);
334 	}
335 
336 	if (action == NULL)
337 		action = kmalloc(sizeof(struct irqaction), GFP_ATOMIC);
338 
339 	if (!action) {
340 		ret = -ENOMEM;
341 		goto out_unlock;
342 	}
343 
344 	action->handler = handler;
345 	action->flags = irqflags;
346 	action->name = devname;
347 	action->next = NULL;
348 	action->dev_id = dev_id;
349 
350 	if (tmp)
351 		tmp->next = action;
352 	else
353 		*actionp = action;
354 
355 	__enable_irq(irq);
356 
357 	ret = 0;
358 out_unlock:
359 	spin_unlock_irqrestore(&irq_action_lock, flags);
360 out:
361 	return ret;
362 }
363 
sun4d_disable_irq(unsigned int irq)364 static void sun4d_disable_irq(unsigned int irq)
365 {
366 	int tid = sbus_tid[(irq >> 5) - 1];
367 	unsigned long flags;
368 
369 	if (irq < NR_IRQS)
370 		return;
371 
372 	spin_lock_irqsave(&sun4d_imsk_lock, flags);
373 	cc_set_imsk_other(tid, cc_get_imsk_other(tid) | (1 << sbus_to_pil[(irq >> 2) & 7]));
374 	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
375 }
376 
sun4d_enable_irq(unsigned int irq)377 static void sun4d_enable_irq(unsigned int irq)
378 {
379 	int tid = sbus_tid[(irq >> 5) - 1];
380 	unsigned long flags;
381 
382 	if (irq < NR_IRQS)
383 		return;
384 
385 	spin_lock_irqsave(&sun4d_imsk_lock, flags);
386 	cc_set_imsk_other(tid, cc_get_imsk_other(tid) & ~(1 << sbus_to_pil[(irq >> 2) & 7]));
387 	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
388 }
389 
390 #ifdef CONFIG_SMP
sun4d_set_cpu_int(int cpu,int level)391 static void sun4d_set_cpu_int(int cpu, int level)
392 {
393 	sun4d_send_ipi(cpu, level);
394 }
395 
sun4d_clear_ipi(int cpu,int level)396 static void sun4d_clear_ipi(int cpu, int level)
397 {
398 }
399 
sun4d_set_udt(int cpu)400 static void sun4d_set_udt(int cpu)
401 {
402 }
403 
404 /* Setup IRQ distribution scheme. */
sun4d_distribute_irqs(void)405 void __init sun4d_distribute_irqs(void)
406 {
407 	struct device_node *dp;
408 
409 	int cpuid = cpu_logical_map(1);
410 
411 	if (cpuid == -1)
412 		cpuid = cpu_logical_map(0);
413 	for_each_node_by_name(dp, "sbi") {
414 		int devid = of_getintprop_default(dp, "device-id", 0);
415 		int board = of_getintprop_default(dp, "board#", 0);
416 		sbus_tid[board] = cpuid;
417 		set_sbi_tid(devid, cpuid << 3);
418 	}
419 	printk(KERN_ERR "All sbus IRQs directed to CPU%d\n", cpuid);
420 }
421 #endif
422 
sun4d_clear_clock_irq(void)423 static void sun4d_clear_clock_irq(void)
424 {
425 	sbus_readl(&sun4d_timers->l10_timer_limit);
426 }
427 
sun4d_load_profile_irq(int cpu,unsigned int limit)428 static void sun4d_load_profile_irq(int cpu, unsigned int limit)
429 {
430 	bw_set_prof_limit(cpu, limit);
431 }
432 
sun4d_load_profile_irqs(void)433 static void __init sun4d_load_profile_irqs(void)
434 {
435 	int cpu = 0, mid;
436 
437 	while (!cpu_find_by_instance(cpu, NULL, &mid)) {
438 		sun4d_load_profile_irq(mid >> 3, 0);
439 		cpu++;
440 	}
441 }
442 
sun4d_build_device_irq(struct platform_device * op,unsigned int real_irq)443 unsigned int sun4d_build_device_irq(struct platform_device *op,
444                                     unsigned int real_irq)
445 {
446 	static int pil_to_sbus[] = {
447 		0, 0, 1, 2, 0, 3, 0, 4, 0, 5, 0, 6, 0, 7, 0, 0,
448 	};
449 	struct device_node *dp = op->dev.of_node;
450 	struct device_node *io_unit, *sbi = dp->parent;
451 	const struct linux_prom_registers *regs;
452 	int board, slot;
453 	int sbusl;
454 
455 	while (sbi) {
456 		if (!strcmp(sbi->name, "sbi"))
457 			break;
458 
459 		sbi = sbi->parent;
460 	}
461 	if (!sbi)
462 		goto err_out;
463 
464 	regs = of_get_property(dp, "reg", NULL);
465 	if (!regs)
466 		goto err_out;
467 
468 	slot = regs->which_io;
469 
470 	/*
471 	 *  If SBI's parent is not io-unit or the io-unit lacks
472 	 * a "board#" property, something is very wrong.
473 	 */
474 	if (!sbi->parent || strcmp(sbi->parent->name, "io-unit")) {
475 		printk("%s: Error, parent is not io-unit.\n", sbi->full_name);
476 		goto err_out;
477 	}
478 	io_unit = sbi->parent;
479 	board = of_getintprop_default(io_unit, "board#", -1);
480 	if (board == -1) {
481 		printk("%s: Error, lacks board# property.\n", io_unit->full_name);
482 		goto err_out;
483 	}
484 
485 	sbusl = pil_to_sbus[real_irq];
486 	if (sbusl)
487 		return (((board + 1) << 5) + (sbusl << 2) + slot);
488 
489 err_out:
490 	return real_irq;
491 }
492 
sun4d_fixup_trap_table(void)493 static void __init sun4d_fixup_trap_table(void)
494 {
495 #ifdef CONFIG_SMP
496 	unsigned long flags;
497 	struct tt_entry *trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (14 - 1)];
498 
499 	/* Adjust so that we jump directly to smp4d_ticker */
500 	lvl14_save[2] += smp4d_ticker - real_irq_entry;
501 
502 	/* For SMP we use the level 14 ticker, however the bootup code
503 	 * has copied the firmware's level 14 vector into the boot cpu's
504 	 * trap table, we must fix this now or we get squashed.
505 	 */
506 	local_irq_save(flags);
507 	patchme_maybe_smp_msg[0] = 0x01000000; /* NOP out the branch */
508 	trap_table->inst_one = lvl14_save[0];
509 	trap_table->inst_two = lvl14_save[1];
510 	trap_table->inst_three = lvl14_save[2];
511 	trap_table->inst_four = lvl14_save[3];
512 	local_flush_cache_all();
513 	local_irq_restore(flags);
514 #endif
515 }
516 
sun4d_init_timers(irq_handler_t counter_fn)517 static void __init sun4d_init_timers(irq_handler_t counter_fn)
518 {
519 	struct device_node *dp;
520 	struct resource res;
521 	const u32 *reg;
522 	int err;
523 
524 	dp = of_find_node_by_name(NULL, "cpu-unit");
525 	if (!dp) {
526 		prom_printf("sun4d_init_timers: Unable to find cpu-unit\n");
527 		prom_halt();
528 	}
529 
530 	/* Which cpu-unit we use is arbitrary, we can view the bootbus timer
531 	 * registers via any cpu's mapping.  The first 'reg' property is the
532 	 * bootbus.
533 	 */
534 	reg = of_get_property(dp, "reg", NULL);
535 	of_node_put(dp);
536 	if (!reg) {
537 		prom_printf("sun4d_init_timers: No reg property\n");
538 		prom_halt();
539 	}
540 
541 	res.start = reg[1];
542 	res.end = reg[2] - 1;
543 	res.flags = reg[0] & 0xff;
544 	sun4d_timers = of_ioremap(&res, BW_TIMER_LIMIT,
545 				  sizeof(struct sun4d_timer_regs), "user timer");
546 	if (!sun4d_timers) {
547 		prom_printf("sun4d_init_timers: Can't map timer regs\n");
548 		prom_halt();
549 	}
550 
551 	sbus_writel((((1000000/HZ) + 1) << 10), &sun4d_timers->l10_timer_limit);
552 
553 	master_l10_counter = &sun4d_timers->l10_cur_count;
554 
555 	err = request_irq(TIMER_IRQ, counter_fn,
556 			  (IRQF_DISABLED | SA_STATIC_ALLOC),
557 			  "timer", NULL);
558 	if (err) {
559 		prom_printf("sun4d_init_timers: request_irq() failed with %d\n",
560 		             err);
561 		prom_halt();
562 	}
563 	sun4d_load_profile_irqs();
564 	sun4d_fixup_trap_table();
565 }
566 
sun4d_init_sbi_irq(void)567 void __init sun4d_init_sbi_irq(void)
568 {
569 	struct device_node *dp;
570 	int target_cpu = 0;
571 
572 #ifdef CONFIG_SMP
573 	target_cpu = boot_cpu_id;
574 #endif
575 
576 	nsbi = 0;
577 	for_each_node_by_name(dp, "sbi")
578 		nsbi++;
579 	sbus_actions = kzalloc(nsbi * 8 * 4 * sizeof(struct sbus_action), GFP_ATOMIC);
580 	if (!sbus_actions) {
581 		prom_printf("SUN4D: Cannot allocate sbus_actions, halting.\n");
582 		prom_halt();
583 	}
584 	for_each_node_by_name(dp, "sbi") {
585 		int devid = of_getintprop_default(dp, "device-id", 0);
586 		int board = of_getintprop_default(dp, "board#", 0);
587 		unsigned int mask;
588 
589 		set_sbi_tid(devid, target_cpu << 3);
590 		sbus_tid[board] = target_cpu;
591 
592 		/* Get rid of pending irqs from PROM */
593 		mask = acquire_sbi(devid, 0xffffffff);
594 		if (mask) {
595 			printk(KERN_ERR "Clearing pending IRQs %08x on SBI %d\n",
596 			       mask, board);
597 			release_sbi(devid, mask);
598 		}
599 	}
600 }
601 
sun4d_init_IRQ(void)602 void __init sun4d_init_IRQ(void)
603 {
604 	local_irq_disable();
605 
606 	BTFIXUPSET_CALL(enable_irq, sun4d_enable_irq, BTFIXUPCALL_NORM);
607 	BTFIXUPSET_CALL(disable_irq, sun4d_disable_irq, BTFIXUPCALL_NORM);
608 	BTFIXUPSET_CALL(clear_clock_irq, sun4d_clear_clock_irq, BTFIXUPCALL_NORM);
609 	BTFIXUPSET_CALL(load_profile_irq, sun4d_load_profile_irq, BTFIXUPCALL_NORM);
610 
611 	sparc_irq_config.init_timers = sun4d_init_timers;
612 	sparc_irq_config.build_device_irq = sun4d_build_device_irq;
613 
614 #ifdef CONFIG_SMP
615 	BTFIXUPSET_CALL(set_cpu_int, sun4d_set_cpu_int, BTFIXUPCALL_NORM);
616 	BTFIXUPSET_CALL(clear_cpu_int, sun4d_clear_ipi, BTFIXUPCALL_NOP);
617 	BTFIXUPSET_CALL(set_irq_udt, sun4d_set_udt, BTFIXUPCALL_NOP);
618 #endif
619 	/* Cannot enable interrupts until OBP ticker is disabled. */
620 }
621