xref: /openbmc/linux/arch/sparc/kernel/sun4d_irq.c (revision 4f6cce39)
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/slab.h>
10 #include <linux/seq_file.h>
11 
12 #include <asm/timer.h>
13 #include <asm/traps.h>
14 #include <asm/irq.h>
15 #include <asm/io.h>
16 #include <asm/sbi.h>
17 #include <asm/cacheflush.h>
18 #include <asm/setup.h>
19 #include <asm/oplib.h>
20 
21 #include "kernel.h"
22 #include "irq.h"
23 
24 /* Sun4d interrupts fall roughly into two categories.  SBUS and
25  * cpu local.  CPU local interrupts cover the timer interrupts
26  * and whatnot, and we encode those as normal PILs between
27  * 0 and 15.
28  * SBUS interrupts are encodes as a combination of board, level and slot.
29  */
30 
31 struct sun4d_handler_data {
32 	unsigned int cpuid;    /* target cpu */
33 	unsigned int real_irq; /* interrupt level */
34 };
35 
36 
37 static unsigned int sun4d_encode_irq(int board, int lvl, int slot)
38 {
39 	return (board + 1) << 5 | (lvl << 2) | slot;
40 }
41 
42 struct sun4d_timer_regs {
43 	u32	l10_timer_limit;
44 	u32	l10_cur_countx;
45 	u32	l10_limit_noclear;
46 	u32	ctrl;
47 	u32	l10_cur_count;
48 };
49 
50 static struct sun4d_timer_regs __iomem *sun4d_timers;
51 
52 #define SUN4D_TIMER_IRQ        10
53 
54 /* Specify which cpu handle interrupts from which board.
55  * Index is board - value is cpu.
56  */
57 static unsigned char board_to_cpu[32];
58 
59 static int pil_to_sbus[] = {
60 	0,
61 	0,
62 	1,
63 	2,
64 	0,
65 	3,
66 	0,
67 	4,
68 	0,
69 	5,
70 	0,
71 	6,
72 	0,
73 	7,
74 	0,
75 	0,
76 };
77 
78 /* Exported for sun4d_smp.c */
79 DEFINE_SPINLOCK(sun4d_imsk_lock);
80 
81 /* SBUS interrupts are encoded integers including the board number
82  * (plus one), the SBUS level, and the SBUS slot number.  Sun4D
83  * IRQ dispatch is done by:
84  *
85  * 1) Reading the BW local interrupt table in order to get the bus
86  *    interrupt mask.
87  *
88  *    This table is indexed by SBUS interrupt level which can be
89  *    derived from the PIL we got interrupted on.
90  *
91  * 2) For each bus showing interrupt pending from #1, read the
92  *    SBI interrupt state register.  This will indicate which slots
93  *    have interrupts pending for that SBUS interrupt level.
94  *
95  * 3) Call the genreric IRQ support.
96  */
97 static void sun4d_sbus_handler_irq(int sbusl)
98 {
99 	unsigned int bus_mask;
100 	unsigned int sbino, slot;
101 	unsigned int sbil;
102 
103 	bus_mask = bw_get_intr_mask(sbusl) & 0x3ffff;
104 	bw_clear_intr_mask(sbusl, bus_mask);
105 
106 	sbil = (sbusl << 2);
107 	/* Loop for each pending SBI */
108 	for (sbino = 0; bus_mask; sbino++, bus_mask >>= 1) {
109 		unsigned int idx, mask;
110 
111 		if (!(bus_mask & 1))
112 			continue;
113 		/* XXX This seems to ACK the irq twice.  acquire_sbi()
114 		 * XXX uses swap, therefore this writes 0xf << sbil,
115 		 * XXX then later release_sbi() will write the individual
116 		 * XXX bits which were set again.
117 		 */
118 		mask = acquire_sbi(SBI2DEVID(sbino), 0xf << sbil);
119 		mask &= (0xf << sbil);
120 
121 		/* Loop for each pending SBI slot */
122 		slot = (1 << sbil);
123 		for (idx = 0; mask != 0; idx++, slot <<= 1) {
124 			unsigned int pil;
125 			struct irq_bucket *p;
126 
127 			if (!(mask & slot))
128 				continue;
129 
130 			mask &= ~slot;
131 			pil = sun4d_encode_irq(sbino, sbusl, idx);
132 
133 			p = irq_map[pil];
134 			while (p) {
135 				struct irq_bucket *next;
136 
137 				next = p->next;
138 				generic_handle_irq(p->irq);
139 				p = next;
140 			}
141 			release_sbi(SBI2DEVID(sbino), slot);
142 		}
143 	}
144 }
145 
146 void sun4d_handler_irq(unsigned int pil, struct pt_regs *regs)
147 {
148 	struct pt_regs *old_regs;
149 	/* SBUS IRQ level (1 - 7) */
150 	int sbusl = pil_to_sbus[pil];
151 
152 	/* FIXME: Is this necessary?? */
153 	cc_get_ipen();
154 
155 	cc_set_iclr(1 << pil);
156 
157 #ifdef CONFIG_SMP
158 	/*
159 	 * Check IPI data structures after IRQ has been cleared. Hard and Soft
160 	 * IRQ can happen at the same time, so both cases are always handled.
161 	 */
162 	if (pil == SUN4D_IPI_IRQ)
163 		sun4d_ipi_interrupt();
164 #endif
165 
166 	old_regs = set_irq_regs(regs);
167 	irq_enter();
168 	if (sbusl == 0) {
169 		/* cpu interrupt */
170 		struct irq_bucket *p;
171 
172 		p = irq_map[pil];
173 		while (p) {
174 			struct irq_bucket *next;
175 
176 			next = p->next;
177 			generic_handle_irq(p->irq);
178 			p = next;
179 		}
180 	} else {
181 		/* SBUS interrupt */
182 		sun4d_sbus_handler_irq(sbusl);
183 	}
184 	irq_exit();
185 	set_irq_regs(old_regs);
186 }
187 
188 
189 static void sun4d_mask_irq(struct irq_data *data)
190 {
191 	struct sun4d_handler_data *handler_data = irq_data_get_irq_handler_data(data);
192 	unsigned int real_irq;
193 #ifdef CONFIG_SMP
194 	int cpuid = handler_data->cpuid;
195 	unsigned long flags;
196 #endif
197 	real_irq = handler_data->real_irq;
198 #ifdef CONFIG_SMP
199 	spin_lock_irqsave(&sun4d_imsk_lock, flags);
200 	cc_set_imsk_other(cpuid, cc_get_imsk_other(cpuid) | (1 << real_irq));
201 	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
202 #else
203 	cc_set_imsk(cc_get_imsk() | (1 << real_irq));
204 #endif
205 }
206 
207 static void sun4d_unmask_irq(struct irq_data *data)
208 {
209 	struct sun4d_handler_data *handler_data = irq_data_get_irq_handler_data(data);
210 	unsigned int real_irq;
211 #ifdef CONFIG_SMP
212 	int cpuid = handler_data->cpuid;
213 	unsigned long flags;
214 #endif
215 	real_irq = handler_data->real_irq;
216 
217 #ifdef CONFIG_SMP
218 	spin_lock_irqsave(&sun4d_imsk_lock, flags);
219 	cc_set_imsk_other(cpuid, cc_get_imsk_other(cpuid) & ~(1 << real_irq));
220 	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
221 #else
222 	cc_set_imsk(cc_get_imsk() & ~(1 << real_irq));
223 #endif
224 }
225 
226 static unsigned int sun4d_startup_irq(struct irq_data *data)
227 {
228 	irq_link(data->irq);
229 	sun4d_unmask_irq(data);
230 	return 0;
231 }
232 
233 static void sun4d_shutdown_irq(struct irq_data *data)
234 {
235 	sun4d_mask_irq(data);
236 	irq_unlink(data->irq);
237 }
238 
239 static struct irq_chip sun4d_irq = {
240 	.name		= "sun4d",
241 	.irq_startup	= sun4d_startup_irq,
242 	.irq_shutdown	= sun4d_shutdown_irq,
243 	.irq_unmask	= sun4d_unmask_irq,
244 	.irq_mask	= sun4d_mask_irq,
245 };
246 
247 #ifdef CONFIG_SMP
248 /* Setup IRQ distribution scheme. */
249 void __init sun4d_distribute_irqs(void)
250 {
251 	struct device_node *dp;
252 
253 	int cpuid = cpu_logical_map(1);
254 
255 	if (cpuid == -1)
256 		cpuid = cpu_logical_map(0);
257 	for_each_node_by_name(dp, "sbi") {
258 		int devid = of_getintprop_default(dp, "device-id", 0);
259 		int board = of_getintprop_default(dp, "board#", 0);
260 		board_to_cpu[board] = cpuid;
261 		set_sbi_tid(devid, cpuid << 3);
262 	}
263 	printk(KERN_ERR "All sbus IRQs directed to CPU%d\n", cpuid);
264 }
265 #endif
266 
267 static void sun4d_clear_clock_irq(void)
268 {
269 	sbus_readl(&sun4d_timers->l10_timer_limit);
270 }
271 
272 static void sun4d_load_profile_irq(int cpu, unsigned int limit)
273 {
274 	unsigned int value = limit ? timer_value(limit) : 0;
275 	bw_set_prof_limit(cpu, value);
276 }
277 
278 static void __init sun4d_load_profile_irqs(void)
279 {
280 	int cpu = 0, mid;
281 
282 	while (!cpu_find_by_instance(cpu, NULL, &mid)) {
283 		sun4d_load_profile_irq(mid >> 3, 0);
284 		cpu++;
285 	}
286 }
287 
288 static unsigned int _sun4d_build_device_irq(unsigned int real_irq,
289                                             unsigned int pil,
290                                             unsigned int board)
291 {
292 	struct sun4d_handler_data *handler_data;
293 	unsigned int irq;
294 
295 	irq = irq_alloc(real_irq, pil);
296 	if (irq == 0) {
297 		prom_printf("IRQ: allocate for %d %d %d failed\n",
298 			real_irq, pil, board);
299 		goto err_out;
300 	}
301 
302 	handler_data = irq_get_handler_data(irq);
303 	if (unlikely(handler_data))
304 		goto err_out;
305 
306 	handler_data = kzalloc(sizeof(struct sun4d_handler_data), GFP_ATOMIC);
307 	if (unlikely(!handler_data)) {
308 		prom_printf("IRQ: kzalloc(sun4d_handler_data) failed.\n");
309 		prom_halt();
310 	}
311 	handler_data->cpuid    = board_to_cpu[board];
312 	handler_data->real_irq = real_irq;
313 	irq_set_chip_and_handler_name(irq, &sun4d_irq,
314 	                              handle_level_irq, "level");
315 	irq_set_handler_data(irq, handler_data);
316 
317 err_out:
318 	return irq;
319 }
320 
321 
322 
323 static unsigned int sun4d_build_device_irq(struct platform_device *op,
324                                            unsigned int real_irq)
325 {
326 	struct device_node *dp = op->dev.of_node;
327 	struct device_node *board_parent, *bus = dp->parent;
328 	char *bus_connection;
329 	const struct linux_prom_registers *regs;
330 	unsigned int pil;
331 	unsigned int irq;
332 	int board, slot;
333 	int sbusl;
334 
335 	irq = real_irq;
336 	while (bus) {
337 		if (!strcmp(bus->name, "sbi")) {
338 			bus_connection = "io-unit";
339 			break;
340 		}
341 
342 		if (!strcmp(bus->name, "bootbus")) {
343 			bus_connection = "cpu-unit";
344 			break;
345 		}
346 
347 		bus = bus->parent;
348 	}
349 	if (!bus)
350 		goto err_out;
351 
352 	regs = of_get_property(dp, "reg", NULL);
353 	if (!regs)
354 		goto err_out;
355 
356 	slot = regs->which_io;
357 
358 	/*
359 	 * If Bus nodes parent is not io-unit/cpu-unit or the io-unit/cpu-unit
360 	 * lacks a "board#" property, something is very wrong.
361 	 */
362 	if (!bus->parent || strcmp(bus->parent->name, bus_connection)) {
363 		printk(KERN_ERR "%s: Error, parent is not %s.\n",
364 			bus->full_name, bus_connection);
365 		goto err_out;
366 	}
367 	board_parent = bus->parent;
368 	board = of_getintprop_default(board_parent, "board#", -1);
369 	if (board == -1) {
370 		printk(KERN_ERR "%s: Error, lacks board# property.\n",
371 			board_parent->full_name);
372 		goto err_out;
373 	}
374 
375 	sbusl = pil_to_sbus[real_irq];
376 	if (sbusl)
377 		pil = sun4d_encode_irq(board, sbusl, slot);
378 	else
379 		pil = real_irq;
380 
381 	irq = _sun4d_build_device_irq(real_irq, pil, board);
382 err_out:
383 	return irq;
384 }
385 
386 static unsigned int sun4d_build_timer_irq(unsigned int board,
387                                           unsigned int real_irq)
388 {
389 	return _sun4d_build_device_irq(real_irq, real_irq, board);
390 }
391 
392 
393 static void __init sun4d_fixup_trap_table(void)
394 {
395 #ifdef CONFIG_SMP
396 	unsigned long flags;
397 	struct tt_entry *trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (14 - 1)];
398 
399 	/* Adjust so that we jump directly to smp4d_ticker */
400 	lvl14_save[2] += smp4d_ticker - real_irq_entry;
401 
402 	/* For SMP we use the level 14 ticker, however the bootup code
403 	 * has copied the firmware's level 14 vector into the boot cpu's
404 	 * trap table, we must fix this now or we get squashed.
405 	 */
406 	local_irq_save(flags);
407 	patchme_maybe_smp_msg[0] = 0x01000000; /* NOP out the branch */
408 	trap_table->inst_one = lvl14_save[0];
409 	trap_table->inst_two = lvl14_save[1];
410 	trap_table->inst_three = lvl14_save[2];
411 	trap_table->inst_four = lvl14_save[3];
412 	local_ops->cache_all();
413 	local_irq_restore(flags);
414 #endif
415 }
416 
417 static void __init sun4d_init_timers(void)
418 {
419 	struct device_node *dp;
420 	struct resource res;
421 	unsigned int irq;
422 	const u32 *reg;
423 	int err;
424 	int board;
425 
426 	dp = of_find_node_by_name(NULL, "cpu-unit");
427 	if (!dp) {
428 		prom_printf("sun4d_init_timers: Unable to find cpu-unit\n");
429 		prom_halt();
430 	}
431 
432 	/* Which cpu-unit we use is arbitrary, we can view the bootbus timer
433 	 * registers via any cpu's mapping.  The first 'reg' property is the
434 	 * bootbus.
435 	 */
436 	reg = of_get_property(dp, "reg", NULL);
437 	if (!reg) {
438 		prom_printf("sun4d_init_timers: No reg property\n");
439 		prom_halt();
440 	}
441 
442 	board = of_getintprop_default(dp, "board#", -1);
443 	if (board == -1) {
444 		prom_printf("sun4d_init_timers: No board# property on cpu-unit\n");
445 		prom_halt();
446 	}
447 
448 	of_node_put(dp);
449 
450 	res.start = reg[1];
451 	res.end = reg[2] - 1;
452 	res.flags = reg[0] & 0xff;
453 	sun4d_timers = of_ioremap(&res, BW_TIMER_LIMIT,
454 				  sizeof(struct sun4d_timer_regs), "user timer");
455 	if (!sun4d_timers) {
456 		prom_printf("sun4d_init_timers: Can't map timer regs\n");
457 		prom_halt();
458 	}
459 
460 #ifdef CONFIG_SMP
461 	sparc_config.cs_period = SBUS_CLOCK_RATE * 2;  /* 2 seconds */
462 #else
463 	sparc_config.cs_period = SBUS_CLOCK_RATE / HZ; /* 1/HZ sec  */
464 	sparc_config.features |= FEAT_L10_CLOCKEVENT;
465 #endif
466 	sparc_config.features |= FEAT_L10_CLOCKSOURCE;
467 	sbus_writel(timer_value(sparc_config.cs_period),
468 		    &sun4d_timers->l10_timer_limit);
469 
470 	master_l10_counter = &sun4d_timers->l10_cur_count;
471 
472 	irq = sun4d_build_timer_irq(board, SUN4D_TIMER_IRQ);
473 	err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL);
474 	if (err) {
475 		prom_printf("sun4d_init_timers: request_irq() failed with %d\n",
476 		             err);
477 		prom_halt();
478 	}
479 	sun4d_load_profile_irqs();
480 	sun4d_fixup_trap_table();
481 }
482 
483 void __init sun4d_init_sbi_irq(void)
484 {
485 	struct device_node *dp;
486 	int target_cpu;
487 
488 	target_cpu = boot_cpu_id;
489 	for_each_node_by_name(dp, "sbi") {
490 		int devid = of_getintprop_default(dp, "device-id", 0);
491 		int board = of_getintprop_default(dp, "board#", 0);
492 		unsigned int mask;
493 
494 		set_sbi_tid(devid, target_cpu << 3);
495 		board_to_cpu[board] = target_cpu;
496 
497 		/* Get rid of pending irqs from PROM */
498 		mask = acquire_sbi(devid, 0xffffffff);
499 		if (mask) {
500 			printk(KERN_ERR "Clearing pending IRQs %08x on SBI %d\n",
501 			       mask, board);
502 			release_sbi(devid, mask);
503 		}
504 	}
505 }
506 
507 void __init sun4d_init_IRQ(void)
508 {
509 	local_irq_disable();
510 
511 	sparc_config.init_timers      = sun4d_init_timers;
512 	sparc_config.build_device_irq = sun4d_build_device_irq;
513 	sparc_config.clock_rate       = SBUS_CLOCK_RATE;
514 	sparc_config.clear_clock_irq  = sun4d_clear_clock_irq;
515 	sparc_config.load_profile_irq = sun4d_load_profile_irq;
516 
517 	/* Cannot enable interrupts until OBP ticker is disabled. */
518 }
519