xref: /openbmc/linux/arch/sparc/kernel/sun4d_irq.c (revision 261a9af6)
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 #include <asm/setup.h>
18 
19 #include "kernel.h"
20 #include "irq.h"
21 
22 /* Sun4d interrupts fall roughly into two categories.  SBUS and
23  * cpu local.  CPU local interrupts cover the timer interrupts
24  * and whatnot, and we encode those as normal PILs between
25  * 0 and 15.
26  * SBUS interrupts are encodes as a combination of board, level and slot.
27  */
28 
29 struct sun4d_handler_data {
30 	unsigned int cpuid;    /* target cpu */
31 	unsigned int real_irq; /* interrupt level */
32 };
33 
34 
35 static unsigned int sun4d_encode_irq(int board, int lvl, int slot)
36 {
37 	return (board + 1) << 5 | (lvl << 2) | slot;
38 }
39 
40 struct sun4d_timer_regs {
41 	u32	l10_timer_limit;
42 	u32	l10_cur_countx;
43 	u32	l10_limit_noclear;
44 	u32	ctrl;
45 	u32	l10_cur_count;
46 };
47 
48 static struct sun4d_timer_regs __iomem *sun4d_timers;
49 
50 #define SUN4D_TIMER_IRQ        10
51 
52 /* Specify which cpu handle interrupts from which board.
53  * Index is board - value is cpu.
54  */
55 static unsigned char board_to_cpu[32];
56 
57 static int pil_to_sbus[] = {
58 	0,
59 	0,
60 	1,
61 	2,
62 	0,
63 	3,
64 	0,
65 	4,
66 	0,
67 	5,
68 	0,
69 	6,
70 	0,
71 	7,
72 	0,
73 	0,
74 };
75 
76 /* Exported for sun4d_smp.c */
77 DEFINE_SPINLOCK(sun4d_imsk_lock);
78 
79 /* SBUS interrupts are encoded integers including the board number
80  * (plus one), the SBUS level, and the SBUS slot number.  Sun4D
81  * IRQ dispatch is done by:
82  *
83  * 1) Reading the BW local interrupt table in order to get the bus
84  *    interrupt mask.
85  *
86  *    This table is indexed by SBUS interrupt level which can be
87  *    derived from the PIL we got interrupted on.
88  *
89  * 2) For each bus showing interrupt pending from #1, read the
90  *    SBI interrupt state register.  This will indicate which slots
91  *    have interrupts pending for that SBUS interrupt level.
92  *
93  * 3) Call the genreric IRQ support.
94  */
95 static void sun4d_sbus_handler_irq(int sbusl)
96 {
97 	unsigned int bus_mask;
98 	unsigned int sbino, slot;
99 	unsigned int sbil;
100 
101 	bus_mask = bw_get_intr_mask(sbusl) & 0x3ffff;
102 	bw_clear_intr_mask(sbusl, bus_mask);
103 
104 	sbil = (sbusl << 2);
105 	/* Loop for each pending SBI */
106 	for (sbino = 0; bus_mask; sbino++, bus_mask >>= 1) {
107 		unsigned int idx, mask;
108 
109 		if (!(bus_mask & 1))
110 			continue;
111 		/* XXX This seems to ACK the irq twice.  acquire_sbi()
112 		 * XXX uses swap, therefore this writes 0xf << sbil,
113 		 * XXX then later release_sbi() will write the individual
114 		 * XXX bits which were set again.
115 		 */
116 		mask = acquire_sbi(SBI2DEVID(sbino), 0xf << sbil);
117 		mask &= (0xf << sbil);
118 
119 		/* Loop for each pending SBI slot */
120 		slot = (1 << sbil);
121 		for (idx = 0; mask != 0; idx++, slot <<= 1) {
122 			unsigned int pil;
123 			struct irq_bucket *p;
124 
125 			if (!(mask & slot))
126 				continue;
127 
128 			mask &= ~slot;
129 			pil = sun4d_encode_irq(sbino, sbusl, idx);
130 
131 			p = irq_map[pil];
132 			while (p) {
133 				struct irq_bucket *next;
134 
135 				next = p->next;
136 				generic_handle_irq(p->irq);
137 				p = next;
138 			}
139 			release_sbi(SBI2DEVID(sbino), slot);
140 		}
141 	}
142 }
143 
144 void sun4d_handler_irq(int pil, struct pt_regs *regs)
145 {
146 	struct pt_regs *old_regs;
147 	/* SBUS IRQ level (1 - 7) */
148 	int sbusl = pil_to_sbus[pil];
149 
150 	/* FIXME: Is this necessary?? */
151 	cc_get_ipen();
152 
153 	cc_set_iclr(1 << pil);
154 
155 #ifdef CONFIG_SMP
156 	/*
157 	 * Check IPI data structures after IRQ has been cleared. Hard and Soft
158 	 * IRQ can happen at the same time, so both cases are always handled.
159 	 */
160 	if (pil == SUN4D_IPI_IRQ)
161 		sun4d_ipi_interrupt();
162 #endif
163 
164 	old_regs = set_irq_regs(regs);
165 	irq_enter();
166 	if (sbusl == 0) {
167 		/* cpu interrupt */
168 		struct irq_bucket *p;
169 
170 		p = irq_map[pil];
171 		while (p) {
172 			struct irq_bucket *next;
173 
174 			next = p->next;
175 			generic_handle_irq(p->irq);
176 			p = next;
177 		}
178 	} else {
179 		/* SBUS interrupt */
180 		sun4d_sbus_handler_irq(sbusl);
181 	}
182 	irq_exit();
183 	set_irq_regs(old_regs);
184 }
185 
186 
187 static void sun4d_mask_irq(struct irq_data *data)
188 {
189 	struct sun4d_handler_data *handler_data = data->handler_data;
190 	unsigned int real_irq;
191 #ifdef CONFIG_SMP
192 	int cpuid = handler_data->cpuid;
193 	unsigned long flags;
194 #endif
195 	real_irq = handler_data->real_irq;
196 #ifdef CONFIG_SMP
197 	spin_lock_irqsave(&sun4d_imsk_lock, flags);
198 	cc_set_imsk_other(cpuid, cc_get_imsk_other(cpuid) | (1 << real_irq));
199 	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
200 #else
201 	cc_set_imsk(cc_get_imsk() | (1 << real_irq));
202 #endif
203 }
204 
205 static void sun4d_unmask_irq(struct irq_data *data)
206 {
207 	struct sun4d_handler_data *handler_data = data->handler_data;
208 	unsigned int real_irq;
209 #ifdef CONFIG_SMP
210 	int cpuid = handler_data->cpuid;
211 	unsigned long flags;
212 #endif
213 	real_irq = handler_data->real_irq;
214 
215 #ifdef CONFIG_SMP
216 	spin_lock_irqsave(&sun4d_imsk_lock, flags);
217 	cc_set_imsk_other(cpuid, cc_get_imsk_other(cpuid) & ~(1 << real_irq));
218 	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
219 #else
220 	cc_set_imsk(cc_get_imsk() & ~(1 << real_irq));
221 #endif
222 }
223 
224 static unsigned int sun4d_startup_irq(struct irq_data *data)
225 {
226 	irq_link(data->irq);
227 	sun4d_unmask_irq(data);
228 	return 0;
229 }
230 
231 static void sun4d_shutdown_irq(struct irq_data *data)
232 {
233 	sun4d_mask_irq(data);
234 	irq_unlink(data->irq);
235 }
236 
237 struct irq_chip sun4d_irq = {
238 	.name		= "sun4d",
239 	.irq_startup	= sun4d_startup_irq,
240 	.irq_shutdown	= sun4d_shutdown_irq,
241 	.irq_unmask	= sun4d_unmask_irq,
242 	.irq_mask	= sun4d_mask_irq,
243 };
244 
245 #ifdef CONFIG_SMP
246 static void sun4d_set_cpu_int(int cpu, int level)
247 {
248 	sun4d_send_ipi(cpu, level);
249 }
250 
251 static void sun4d_clear_ipi(int cpu, int level)
252 {
253 }
254 
255 static void sun4d_set_udt(int cpu)
256 {
257 }
258 
259 /* Setup IRQ distribution scheme. */
260 void __init sun4d_distribute_irqs(void)
261 {
262 	struct device_node *dp;
263 
264 	int cpuid = cpu_logical_map(1);
265 
266 	if (cpuid == -1)
267 		cpuid = cpu_logical_map(0);
268 	for_each_node_by_name(dp, "sbi") {
269 		int devid = of_getintprop_default(dp, "device-id", 0);
270 		int board = of_getintprop_default(dp, "board#", 0);
271 		board_to_cpu[board] = cpuid;
272 		set_sbi_tid(devid, cpuid << 3);
273 	}
274 	printk(KERN_ERR "All sbus IRQs directed to CPU%d\n", cpuid);
275 }
276 #endif
277 
278 static void sun4d_clear_clock_irq(void)
279 {
280 	sbus_readl(&sun4d_timers->l10_timer_limit);
281 }
282 
283 static void sun4d_load_profile_irq(int cpu, unsigned int limit)
284 {
285 	bw_set_prof_limit(cpu, limit);
286 }
287 
288 static void __init sun4d_load_profile_irqs(void)
289 {
290 	int cpu = 0, mid;
291 
292 	while (!cpu_find_by_instance(cpu, NULL, &mid)) {
293 		sun4d_load_profile_irq(mid >> 3, 0);
294 		cpu++;
295 	}
296 }
297 
298 unsigned int _sun4d_build_device_irq(unsigned int real_irq,
299                                      unsigned int pil,
300                                      unsigned int board)
301 {
302 	struct sun4d_handler_data *handler_data;
303 	unsigned int irq;
304 
305 	irq = irq_alloc(real_irq, pil);
306 	if (irq == 0) {
307 		prom_printf("IRQ: allocate for %d %d %d failed\n",
308 			real_irq, pil, board);
309 		goto err_out;
310 	}
311 
312 	handler_data = irq_get_handler_data(irq);
313 	if (unlikely(handler_data))
314 		goto err_out;
315 
316 	handler_data = kzalloc(sizeof(struct sun4d_handler_data), GFP_ATOMIC);
317 	if (unlikely(!handler_data)) {
318 		prom_printf("IRQ: kzalloc(sun4d_handler_data) failed.\n");
319 		prom_halt();
320 	}
321 	handler_data->cpuid    = board_to_cpu[board];
322 	handler_data->real_irq = real_irq;
323 	irq_set_chip_and_handler_name(irq, &sun4d_irq,
324 	                              handle_level_irq, "level");
325 	irq_set_handler_data(irq, handler_data);
326 
327 err_out:
328 	return irq;
329 }
330 
331 
332 
333 unsigned int sun4d_build_device_irq(struct platform_device *op,
334                                     unsigned int real_irq)
335 {
336 	struct device_node *dp = op->dev.of_node;
337 	struct device_node *board_parent, *bus = dp->parent;
338 	char *bus_connection;
339 	const struct linux_prom_registers *regs;
340 	unsigned int pil;
341 	unsigned int irq;
342 	int board, slot;
343 	int sbusl;
344 
345 	irq = real_irq;
346 	while (bus) {
347 		if (!strcmp(bus->name, "sbi")) {
348 			bus_connection = "io-unit";
349 			break;
350 		}
351 
352 		if (!strcmp(bus->name, "bootbus")) {
353 			bus_connection = "cpu-unit";
354 			break;
355 		}
356 
357 		bus = bus->parent;
358 	}
359 	if (!bus)
360 		goto err_out;
361 
362 	regs = of_get_property(dp, "reg", NULL);
363 	if (!regs)
364 		goto err_out;
365 
366 	slot = regs->which_io;
367 
368 	/*
369 	 * If Bus nodes parent is not io-unit/cpu-unit or the io-unit/cpu-unit
370 	 * lacks a "board#" property, something is very wrong.
371 	 */
372 	if (!bus->parent || strcmp(bus->parent->name, bus_connection)) {
373 		printk(KERN_ERR "%s: Error, parent is not %s.\n",
374 			bus->full_name, bus_connection);
375 		goto err_out;
376 	}
377 	board_parent = bus->parent;
378 	board = of_getintprop_default(board_parent, "board#", -1);
379 	if (board == -1) {
380 		printk(KERN_ERR "%s: Error, lacks board# property.\n",
381 			board_parent->full_name);
382 		goto err_out;
383 	}
384 
385 	sbusl = pil_to_sbus[real_irq];
386 	if (sbusl)
387 		pil = sun4d_encode_irq(board, sbusl, slot);
388 	else
389 		pil = real_irq;
390 
391 	irq = _sun4d_build_device_irq(real_irq, pil, board);
392 err_out:
393 	return irq;
394 }
395 
396 unsigned int sun4d_build_timer_irq(unsigned int board, unsigned int real_irq)
397 {
398 	return _sun4d_build_device_irq(real_irq, real_irq, board);
399 }
400 
401 
402 static void __init sun4d_fixup_trap_table(void)
403 {
404 #ifdef CONFIG_SMP
405 	unsigned long flags;
406 	struct tt_entry *trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (14 - 1)];
407 
408 	/* Adjust so that we jump directly to smp4d_ticker */
409 	lvl14_save[2] += smp4d_ticker - real_irq_entry;
410 
411 	/* For SMP we use the level 14 ticker, however the bootup code
412 	 * has copied the firmware's level 14 vector into the boot cpu's
413 	 * trap table, we must fix this now or we get squashed.
414 	 */
415 	local_irq_save(flags);
416 	patchme_maybe_smp_msg[0] = 0x01000000; /* NOP out the branch */
417 	trap_table->inst_one = lvl14_save[0];
418 	trap_table->inst_two = lvl14_save[1];
419 	trap_table->inst_three = lvl14_save[2];
420 	trap_table->inst_four = lvl14_save[3];
421 	local_flush_cache_all();
422 	local_irq_restore(flags);
423 #endif
424 }
425 
426 static void __init sun4d_init_timers(irq_handler_t counter_fn)
427 {
428 	struct device_node *dp;
429 	struct resource res;
430 	unsigned int irq;
431 	const u32 *reg;
432 	int err;
433 	int board;
434 
435 	dp = of_find_node_by_name(NULL, "cpu-unit");
436 	if (!dp) {
437 		prom_printf("sun4d_init_timers: Unable to find cpu-unit\n");
438 		prom_halt();
439 	}
440 
441 	/* Which cpu-unit we use is arbitrary, we can view the bootbus timer
442 	 * registers via any cpu's mapping.  The first 'reg' property is the
443 	 * bootbus.
444 	 */
445 	reg = of_get_property(dp, "reg", NULL);
446 	if (!reg) {
447 		prom_printf("sun4d_init_timers: No reg property\n");
448 		prom_halt();
449 	}
450 
451 	board = of_getintprop_default(dp, "board#", -1);
452 	if (board == -1) {
453 		prom_printf("sun4d_init_timers: No board# property on cpu-unit\n");
454 		prom_halt();
455 	}
456 
457 	of_node_put(dp);
458 
459 	res.start = reg[1];
460 	res.end = reg[2] - 1;
461 	res.flags = reg[0] & 0xff;
462 	sun4d_timers = of_ioremap(&res, BW_TIMER_LIMIT,
463 				  sizeof(struct sun4d_timer_regs), "user timer");
464 	if (!sun4d_timers) {
465 		prom_printf("sun4d_init_timers: Can't map timer regs\n");
466 		prom_halt();
467 	}
468 
469 	sbus_writel((((1000000/HZ) + 1) << 10), &sun4d_timers->l10_timer_limit);
470 
471 	master_l10_counter = &sun4d_timers->l10_cur_count;
472 
473 	irq = sun4d_build_timer_irq(board, SUN4D_TIMER_IRQ);
474 	err = request_irq(irq, counter_fn, IRQF_TIMER, "timer", NULL);
475 	if (err) {
476 		prom_printf("sun4d_init_timers: request_irq() failed with %d\n",
477 		             err);
478 		prom_halt();
479 	}
480 	sun4d_load_profile_irqs();
481 	sun4d_fixup_trap_table();
482 }
483 
484 void __init sun4d_init_sbi_irq(void)
485 {
486 	struct device_node *dp;
487 	int target_cpu;
488 
489 	target_cpu = boot_cpu_id;
490 	for_each_node_by_name(dp, "sbi") {
491 		int devid = of_getintprop_default(dp, "device-id", 0);
492 		int board = of_getintprop_default(dp, "board#", 0);
493 		unsigned int mask;
494 
495 		set_sbi_tid(devid, target_cpu << 3);
496 		board_to_cpu[board] = target_cpu;
497 
498 		/* Get rid of pending irqs from PROM */
499 		mask = acquire_sbi(devid, 0xffffffff);
500 		if (mask) {
501 			printk(KERN_ERR "Clearing pending IRQs %08x on SBI %d\n",
502 			       mask, board);
503 			release_sbi(devid, mask);
504 		}
505 	}
506 }
507 
508 void __init sun4d_init_IRQ(void)
509 {
510 	local_irq_disable();
511 
512 	BTFIXUPSET_CALL(clear_clock_irq, sun4d_clear_clock_irq, BTFIXUPCALL_NORM);
513 	BTFIXUPSET_CALL(load_profile_irq, sun4d_load_profile_irq, BTFIXUPCALL_NORM);
514 
515 	sparc_irq_config.init_timers      = sun4d_init_timers;
516 	sparc_irq_config.build_device_irq = sun4d_build_device_irq;
517 
518 #ifdef CONFIG_SMP
519 	BTFIXUPSET_CALL(set_cpu_int, sun4d_set_cpu_int, BTFIXUPCALL_NORM);
520 	BTFIXUPSET_CALL(clear_cpu_int, sun4d_clear_ipi, BTFIXUPCALL_NOP);
521 	BTFIXUPSET_CALL(set_irq_udt, sun4d_set_udt, BTFIXUPCALL_NOP);
522 #endif
523 	/* Cannot enable interrupts until OBP ticker is disabled. */
524 }
525