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
31struct sun4d_handler_data {
32	unsigned int cpuid;    /* target cpu */
33	unsigned int real_irq; /* interrupt level */
34};
35
36
37static unsigned int sun4d_encode_irq(int board, int lvl, int slot)
38{
39	return (board + 1) << 5 | (lvl << 2) | slot;
40}
41
42struct 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
50static 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 */
57static unsigned char board_to_cpu[32];
58
59static 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 */
79DEFINE_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 */
97static 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
146void 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
189static 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
207static 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
226static 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
233static void sun4d_shutdown_irq(struct irq_data *data)
234{
235	sun4d_mask_irq(data);
236	irq_unlink(data->irq);
237}
238
239static 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. */
249void __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
267static void sun4d_clear_clock_irq(void)
268{
269	sbus_readl(&sun4d_timers->l10_timer_limit);
270}
271
272static 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
278static 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
288static 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
317err_out:
318	return irq;
319}
320
321
322
323static 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);
382err_out:
383	return irq;
384}
385
386static 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
393static 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
417static 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
483void __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
507void __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