xref: /openbmc/linux/arch/sparc/kernel/time_64.c (revision b60a5b8d)
1 // SPDX-License-Identifier: GPL-2.0
2 /* time.c: UltraSparc timer and TOD clock support.
3  *
4  * Copyright (C) 1997, 2008 David S. Miller (davem@davemloft.net)
5  * Copyright (C) 1998 Eddie C. Dost   (ecd@skynet.be)
6  *
7  * Based largely on code which is:
8  *
9  * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
10  */
11 
12 #include <linux/errno.h>
13 #include <linux/export.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/param.h>
17 #include <linux/string.h>
18 #include <linux/mm.h>
19 #include <linux/interrupt.h>
20 #include <linux/time.h>
21 #include <linux/timex.h>
22 #include <linux/init.h>
23 #include <linux/ioport.h>
24 #include <linux/mc146818rtc.h>
25 #include <linux/delay.h>
26 #include <linux/profile.h>
27 #include <linux/bcd.h>
28 #include <linux/jiffies.h>
29 #include <linux/cpufreq.h>
30 #include <linux/percpu.h>
31 #include <linux/rtc/m48t59.h>
32 #include <linux/kernel_stat.h>
33 #include <linux/clockchips.h>
34 #include <linux/clocksource.h>
35 #include <linux/platform_device.h>
36 #include <linux/ftrace.h>
37 
38 #include <asm/oplib.h>
39 #include <asm/timer.h>
40 #include <asm/irq.h>
41 #include <asm/io.h>
42 #include <asm/prom.h>
43 #include <asm/starfire.h>
44 #include <asm/smp.h>
45 #include <asm/sections.h>
46 #include <asm/cpudata.h>
47 #include <linux/uaccess.h>
48 #include <asm/irq_regs.h>
49 #include <asm/cacheflush.h>
50 
51 #include "entry.h"
52 #include "kernel.h"
53 
54 DEFINE_SPINLOCK(rtc_lock);
55 
56 #ifdef CONFIG_SMP
57 unsigned long profile_pc(struct pt_regs *regs)
58 {
59 	unsigned long pc = instruction_pointer(regs);
60 
61 	if (in_lock_functions(pc))
62 		return regs->u_regs[UREG_RETPC];
63 	return pc;
64 }
65 EXPORT_SYMBOL(profile_pc);
66 #endif
67 
68 static void tick_disable_protection(void)
69 {
70 	/* Set things up so user can access tick register for profiling
71 	 * purposes.  Also workaround BB_ERRATA_1 by doing a dummy
72 	 * read back of %tick after writing it.
73 	 */
74 	__asm__ __volatile__(
75 	"	ba,pt	%%xcc, 1f\n"
76 	"	 nop\n"
77 	"	.align	64\n"
78 	"1:	rd	%%tick, %%g2\n"
79 	"	add	%%g2, 6, %%g2\n"
80 	"	andn	%%g2, %0, %%g2\n"
81 	"	wrpr	%%g2, 0, %%tick\n"
82 	"	rdpr	%%tick, %%g0"
83 	: /* no outputs */
84 	: "r" (TICK_PRIV_BIT)
85 	: "g2");
86 }
87 
88 static void tick_disable_irq(void)
89 {
90 	__asm__ __volatile__(
91 	"	ba,pt	%%xcc, 1f\n"
92 	"	 nop\n"
93 	"	.align	64\n"
94 	"1:	wr	%0, 0x0, %%tick_cmpr\n"
95 	"	rd	%%tick_cmpr, %%g0"
96 	: /* no outputs */
97 	: "r" (TICKCMP_IRQ_BIT));
98 }
99 
100 static void tick_init_tick(void)
101 {
102 	tick_disable_protection();
103 	tick_disable_irq();
104 }
105 
106 static unsigned long long tick_get_tick(void)
107 {
108 	unsigned long ret;
109 
110 	__asm__ __volatile__("rd	%%tick, %0\n\t"
111 			     "mov	%0, %0"
112 			     : "=r" (ret));
113 
114 	return ret & ~TICK_PRIV_BIT;
115 }
116 
117 static int tick_add_compare(unsigned long adj)
118 {
119 	unsigned long orig_tick, new_tick, new_compare;
120 
121 	__asm__ __volatile__("rd	%%tick, %0"
122 			     : "=r" (orig_tick));
123 
124 	orig_tick &= ~TICKCMP_IRQ_BIT;
125 
126 	/* Workaround for Spitfire Errata (#54 I think??), I discovered
127 	 * this via Sun BugID 4008234, mentioned in Solaris-2.5.1 patch
128 	 * number 103640.
129 	 *
130 	 * On Blackbird writes to %tick_cmpr can fail, the
131 	 * workaround seems to be to execute the wr instruction
132 	 * at the start of an I-cache line, and perform a dummy
133 	 * read back from %tick_cmpr right after writing to it. -DaveM
134 	 */
135 	__asm__ __volatile__("ba,pt	%%xcc, 1f\n\t"
136 			     " add	%1, %2, %0\n\t"
137 			     ".align	64\n"
138 			     "1:\n\t"
139 			     "wr	%0, 0, %%tick_cmpr\n\t"
140 			     "rd	%%tick_cmpr, %%g0\n\t"
141 			     : "=r" (new_compare)
142 			     : "r" (orig_tick), "r" (adj));
143 
144 	__asm__ __volatile__("rd	%%tick, %0"
145 			     : "=r" (new_tick));
146 	new_tick &= ~TICKCMP_IRQ_BIT;
147 
148 	return ((long)(new_tick - (orig_tick+adj))) > 0L;
149 }
150 
151 static unsigned long tick_add_tick(unsigned long adj)
152 {
153 	unsigned long new_tick;
154 
155 	/* Also need to handle Blackbird bug here too. */
156 	__asm__ __volatile__("rd	%%tick, %0\n\t"
157 			     "add	%0, %1, %0\n\t"
158 			     "wrpr	%0, 0, %%tick\n\t"
159 			     : "=&r" (new_tick)
160 			     : "r" (adj));
161 
162 	return new_tick;
163 }
164 
165 /* Searches for cpu clock frequency with given cpuid in OpenBoot tree */
166 static unsigned long cpuid_to_freq(phandle node, int cpuid)
167 {
168 	bool is_cpu_node = false;
169 	unsigned long freq = 0;
170 	char type[128];
171 
172 	if (!node)
173 		return freq;
174 
175 	if (prom_getproperty(node, "device_type", type, sizeof(type)) != -1)
176 		is_cpu_node = (strcmp(type, "cpu") == 0);
177 
178 	/* try upa-portid then cpuid to get cpuid, see prom_64.c */
179 	if (is_cpu_node && (prom_getint(node, "upa-portid") == cpuid ||
180 			    prom_getint(node, "cpuid") == cpuid))
181 		freq = prom_getintdefault(node, "clock-frequency", 0);
182 	if (!freq)
183 		freq = cpuid_to_freq(prom_getchild(node), cpuid);
184 	if (!freq)
185 		freq = cpuid_to_freq(prom_getsibling(node), cpuid);
186 
187 	return freq;
188 }
189 
190 static unsigned long tick_get_frequency(void)
191 {
192 	return cpuid_to_freq(prom_root_node, hard_smp_processor_id());
193 }
194 
195 static struct sparc64_tick_ops tick_operations __cacheline_aligned = {
196 	.name		=	"tick",
197 	.init_tick	=	tick_init_tick,
198 	.disable_irq	=	tick_disable_irq,
199 	.get_tick	=	tick_get_tick,
200 	.add_tick	=	tick_add_tick,
201 	.add_compare	=	tick_add_compare,
202 	.get_frequency	=	tick_get_frequency,
203 	.softint_mask	=	1UL << 0,
204 };
205 
206 struct sparc64_tick_ops *tick_ops __read_mostly = &tick_operations;
207 EXPORT_SYMBOL(tick_ops);
208 
209 static void stick_disable_irq(void)
210 {
211 	__asm__ __volatile__(
212 	"wr	%0, 0x0, %%asr25"
213 	: /* no outputs */
214 	: "r" (TICKCMP_IRQ_BIT));
215 }
216 
217 static void stick_init_tick(void)
218 {
219 	/* Writes to the %tick and %stick register are not
220 	 * allowed on sun4v.  The Hypervisor controls that
221 	 * bit, per-strand.
222 	 */
223 	if (tlb_type != hypervisor) {
224 		tick_disable_protection();
225 		tick_disable_irq();
226 
227 		/* Let the user get at STICK too. */
228 		__asm__ __volatile__(
229 		"	rd	%%asr24, %%g2\n"
230 		"	andn	%%g2, %0, %%g2\n"
231 		"	wr	%%g2, 0, %%asr24"
232 		: /* no outputs */
233 		: "r" (TICK_PRIV_BIT)
234 		: "g1", "g2");
235 	}
236 
237 	stick_disable_irq();
238 }
239 
240 static unsigned long long stick_get_tick(void)
241 {
242 	unsigned long ret;
243 
244 	__asm__ __volatile__("rd	%%asr24, %0"
245 			     : "=r" (ret));
246 
247 	return ret & ~TICK_PRIV_BIT;
248 }
249 
250 static unsigned long stick_add_tick(unsigned long adj)
251 {
252 	unsigned long new_tick;
253 
254 	__asm__ __volatile__("rd	%%asr24, %0\n\t"
255 			     "add	%0, %1, %0\n\t"
256 			     "wr	%0, 0, %%asr24\n\t"
257 			     : "=&r" (new_tick)
258 			     : "r" (adj));
259 
260 	return new_tick;
261 }
262 
263 static int stick_add_compare(unsigned long adj)
264 {
265 	unsigned long orig_tick, new_tick;
266 
267 	__asm__ __volatile__("rd	%%asr24, %0"
268 			     : "=r" (orig_tick));
269 	orig_tick &= ~TICKCMP_IRQ_BIT;
270 
271 	__asm__ __volatile__("wr	%0, 0, %%asr25"
272 			     : /* no outputs */
273 			     : "r" (orig_tick + adj));
274 
275 	__asm__ __volatile__("rd	%%asr24, %0"
276 			     : "=r" (new_tick));
277 	new_tick &= ~TICKCMP_IRQ_BIT;
278 
279 	return ((long)(new_tick - (orig_tick+adj))) > 0L;
280 }
281 
282 static unsigned long stick_get_frequency(void)
283 {
284 	return prom_getintdefault(prom_root_node, "stick-frequency", 0);
285 }
286 
287 static struct sparc64_tick_ops stick_operations __read_mostly = {
288 	.name		=	"stick",
289 	.init_tick	=	stick_init_tick,
290 	.disable_irq	=	stick_disable_irq,
291 	.get_tick	=	stick_get_tick,
292 	.add_tick	=	stick_add_tick,
293 	.add_compare	=	stick_add_compare,
294 	.get_frequency	=	stick_get_frequency,
295 	.softint_mask	=	1UL << 16,
296 };
297 
298 /* On Hummingbird the STICK/STICK_CMPR register is implemented
299  * in I/O space.  There are two 64-bit registers each, the
300  * first holds the low 32-bits of the value and the second holds
301  * the high 32-bits.
302  *
303  * Since STICK is constantly updating, we have to access it carefully.
304  *
305  * The sequence we use to read is:
306  * 1) read high
307  * 2) read low
308  * 3) read high again, if it rolled re-read both low and high again.
309  *
310  * Writing STICK safely is also tricky:
311  * 1) write low to zero
312  * 2) write high
313  * 3) write low
314  */
315 static unsigned long __hbird_read_stick(void)
316 {
317 	unsigned long ret, tmp1, tmp2, tmp3;
318 	unsigned long addr = HBIRD_STICK_ADDR+8;
319 
320 	__asm__ __volatile__("ldxa	[%1] %5, %2\n"
321 			     "1:\n\t"
322 			     "sub	%1, 0x8, %1\n\t"
323 			     "ldxa	[%1] %5, %3\n\t"
324 			     "add	%1, 0x8, %1\n\t"
325 			     "ldxa	[%1] %5, %4\n\t"
326 			     "cmp	%4, %2\n\t"
327 			     "bne,a,pn	%%xcc, 1b\n\t"
328 			     " mov	%4, %2\n\t"
329 			     "sllx	%4, 32, %4\n\t"
330 			     "or	%3, %4, %0\n\t"
331 			     : "=&r" (ret), "=&r" (addr),
332 			       "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3)
333 			     : "i" (ASI_PHYS_BYPASS_EC_E), "1" (addr));
334 
335 	return ret;
336 }
337 
338 static void __hbird_write_stick(unsigned long val)
339 {
340 	unsigned long low = (val & 0xffffffffUL);
341 	unsigned long high = (val >> 32UL);
342 	unsigned long addr = HBIRD_STICK_ADDR;
343 
344 	__asm__ __volatile__("stxa	%%g0, [%0] %4\n\t"
345 			     "add	%0, 0x8, %0\n\t"
346 			     "stxa	%3, [%0] %4\n\t"
347 			     "sub	%0, 0x8, %0\n\t"
348 			     "stxa	%2, [%0] %4"
349 			     : "=&r" (addr)
350 			     : "0" (addr), "r" (low), "r" (high),
351 			       "i" (ASI_PHYS_BYPASS_EC_E));
352 }
353 
354 static void __hbird_write_compare(unsigned long val)
355 {
356 	unsigned long low = (val & 0xffffffffUL);
357 	unsigned long high = (val >> 32UL);
358 	unsigned long addr = HBIRD_STICKCMP_ADDR + 0x8UL;
359 
360 	__asm__ __volatile__("stxa	%3, [%0] %4\n\t"
361 			     "sub	%0, 0x8, %0\n\t"
362 			     "stxa	%2, [%0] %4"
363 			     : "=&r" (addr)
364 			     : "0" (addr), "r" (low), "r" (high),
365 			       "i" (ASI_PHYS_BYPASS_EC_E));
366 }
367 
368 static void hbtick_disable_irq(void)
369 {
370 	__hbird_write_compare(TICKCMP_IRQ_BIT);
371 }
372 
373 static void hbtick_init_tick(void)
374 {
375 	tick_disable_protection();
376 
377 	/* XXX This seems to be necessary to 'jumpstart' Hummingbird
378 	 * XXX into actually sending STICK interrupts.  I think because
379 	 * XXX of how we store %tick_cmpr in head.S this somehow resets the
380 	 * XXX {TICK + STICK} interrupt mux.  -DaveM
381 	 */
382 	__hbird_write_stick(__hbird_read_stick());
383 
384 	hbtick_disable_irq();
385 }
386 
387 static unsigned long long hbtick_get_tick(void)
388 {
389 	return __hbird_read_stick() & ~TICK_PRIV_BIT;
390 }
391 
392 static unsigned long hbtick_add_tick(unsigned long adj)
393 {
394 	unsigned long val;
395 
396 	val = __hbird_read_stick() + adj;
397 	__hbird_write_stick(val);
398 
399 	return val;
400 }
401 
402 static int hbtick_add_compare(unsigned long adj)
403 {
404 	unsigned long val = __hbird_read_stick();
405 	unsigned long val2;
406 
407 	val &= ~TICKCMP_IRQ_BIT;
408 	val += adj;
409 	__hbird_write_compare(val);
410 
411 	val2 = __hbird_read_stick() & ~TICKCMP_IRQ_BIT;
412 
413 	return ((long)(val2 - val)) > 0L;
414 }
415 
416 static unsigned long hbtick_get_frequency(void)
417 {
418 	return prom_getintdefault(prom_root_node, "stick-frequency", 0);
419 }
420 
421 static struct sparc64_tick_ops hbtick_operations __read_mostly = {
422 	.name		=	"hbtick",
423 	.init_tick	=	hbtick_init_tick,
424 	.disable_irq	=	hbtick_disable_irq,
425 	.get_tick	=	hbtick_get_tick,
426 	.add_tick	=	hbtick_add_tick,
427 	.add_compare	=	hbtick_add_compare,
428 	.get_frequency	=	hbtick_get_frequency,
429 	.softint_mask	=	1UL << 0,
430 };
431 
432 unsigned long cmos_regs;
433 EXPORT_SYMBOL(cmos_regs);
434 
435 static struct resource rtc_cmos_resource;
436 
437 static struct platform_device rtc_cmos_device = {
438 	.name		= "rtc_cmos",
439 	.id		= -1,
440 	.resource	= &rtc_cmos_resource,
441 	.num_resources	= 1,
442 };
443 
444 static int rtc_probe(struct platform_device *op)
445 {
446 	struct resource *r;
447 
448 	printk(KERN_INFO "%pOF: RTC regs at 0x%llx\n",
449 	       op->dev.of_node, op->resource[0].start);
450 
451 	/* The CMOS RTC driver only accepts IORESOURCE_IO, so cons
452 	 * up a fake resource so that the probe works for all cases.
453 	 * When the RTC is behind an ISA bus it will have IORESOURCE_IO
454 	 * already, whereas when it's behind EBUS is will be IORESOURCE_MEM.
455 	 */
456 
457 	r = &rtc_cmos_resource;
458 	r->flags = IORESOURCE_IO;
459 	r->name = op->resource[0].name;
460 	r->start = op->resource[0].start;
461 	r->end = op->resource[0].end;
462 
463 	cmos_regs = op->resource[0].start;
464 	return platform_device_register(&rtc_cmos_device);
465 }
466 
467 static const struct of_device_id rtc_match[] = {
468 	{
469 		.name = "rtc",
470 		.compatible = "m5819",
471 	},
472 	{
473 		.name = "rtc",
474 		.compatible = "isa-m5819p",
475 	},
476 	{
477 		.name = "rtc",
478 		.compatible = "isa-m5823p",
479 	},
480 	{
481 		.name = "rtc",
482 		.compatible = "ds1287",
483 	},
484 	{},
485 };
486 
487 static struct platform_driver rtc_driver = {
488 	.probe		= rtc_probe,
489 	.driver = {
490 		.name = "rtc",
491 		.of_match_table = rtc_match,
492 	},
493 };
494 
495 static struct platform_device rtc_bq4802_device = {
496 	.name		= "rtc-bq4802",
497 	.id		= -1,
498 	.num_resources	= 1,
499 };
500 
501 static int bq4802_probe(struct platform_device *op)
502 {
503 
504 	printk(KERN_INFO "%pOF: BQ4802 regs at 0x%llx\n",
505 	       op->dev.of_node, op->resource[0].start);
506 
507 	rtc_bq4802_device.resource = &op->resource[0];
508 	return platform_device_register(&rtc_bq4802_device);
509 }
510 
511 static const struct of_device_id bq4802_match[] = {
512 	{
513 		.name = "rtc",
514 		.compatible = "bq4802",
515 	},
516 	{},
517 };
518 
519 static struct platform_driver bq4802_driver = {
520 	.probe		= bq4802_probe,
521 	.driver = {
522 		.name = "bq4802",
523 		.of_match_table = bq4802_match,
524 	},
525 };
526 
527 static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
528 {
529 	struct platform_device *pdev = to_platform_device(dev);
530 	void __iomem *regs = (void __iomem *) pdev->resource[0].start;
531 
532 	return readb(regs + ofs);
533 }
534 
535 static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
536 {
537 	struct platform_device *pdev = to_platform_device(dev);
538 	void __iomem *regs = (void __iomem *) pdev->resource[0].start;
539 
540 	writeb(val, regs + ofs);
541 }
542 
543 static struct m48t59_plat_data m48t59_data = {
544 	.read_byte	= mostek_read_byte,
545 	.write_byte	= mostek_write_byte,
546 };
547 
548 static struct platform_device m48t59_rtc = {
549 	.name		= "rtc-m48t59",
550 	.id		= 0,
551 	.num_resources	= 1,
552 	.dev	= {
553 		.platform_data = &m48t59_data,
554 	},
555 };
556 
557 static int mostek_probe(struct platform_device *op)
558 {
559 	struct device_node *dp = op->dev.of_node;
560 
561 	/* On an Enterprise system there can be multiple mostek clocks.
562 	 * We should only match the one that is on the central FHC bus.
563 	 */
564 	if (of_node_name_eq(dp->parent, "fhc") &&
565 	    !of_node_name_eq(dp->parent->parent, "central"))
566 		return -ENODEV;
567 
568 	printk(KERN_INFO "%pOF: Mostek regs at 0x%llx\n",
569 	       dp, op->resource[0].start);
570 
571 	m48t59_rtc.resource = &op->resource[0];
572 	return platform_device_register(&m48t59_rtc);
573 }
574 
575 static const struct of_device_id mostek_match[] = {
576 	{
577 		.name = "eeprom",
578 	},
579 	{},
580 };
581 
582 static struct platform_driver mostek_driver = {
583 	.probe		= mostek_probe,
584 	.driver = {
585 		.name = "mostek",
586 		.of_match_table = mostek_match,
587 	},
588 };
589 
590 static struct platform_device rtc_sun4v_device = {
591 	.name		= "rtc-sun4v",
592 	.id		= -1,
593 };
594 
595 static struct platform_device rtc_starfire_device = {
596 	.name		= "rtc-starfire",
597 	.id		= -1,
598 };
599 
600 static int __init clock_init(void)
601 {
602 	if (this_is_starfire)
603 		return platform_device_register(&rtc_starfire_device);
604 
605 	if (tlb_type == hypervisor)
606 		return platform_device_register(&rtc_sun4v_device);
607 
608 	(void) platform_driver_register(&rtc_driver);
609 	(void) platform_driver_register(&mostek_driver);
610 	(void) platform_driver_register(&bq4802_driver);
611 
612 	return 0;
613 }
614 
615 /* Must be after subsys_initcall() so that busses are probed.  Must
616  * be before device_initcall() because things like the RTC driver
617  * need to see the clock registers.
618  */
619 fs_initcall(clock_init);
620 
621 /* Return true if this is Hummingbird, aka Ultra-IIe */
622 static bool is_hummingbird(void)
623 {
624 	unsigned long ver, manuf, impl;
625 
626 	__asm__ __volatile__ ("rdpr %%ver, %0"
627 			      : "=&r" (ver));
628 	manuf = ((ver >> 48) & 0xffff);
629 	impl = ((ver >> 32) & 0xffff);
630 
631 	return (manuf == 0x17 && impl == 0x13);
632 }
633 
634 struct freq_table {
635 	unsigned long clock_tick_ref;
636 	unsigned int ref_freq;
637 };
638 static DEFINE_PER_CPU(struct freq_table, sparc64_freq_table) = { 0, 0 };
639 
640 unsigned long sparc64_get_clock_tick(unsigned int cpu)
641 {
642 	struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
643 
644 	if (ft->clock_tick_ref)
645 		return ft->clock_tick_ref;
646 	return cpu_data(cpu).clock_tick;
647 }
648 EXPORT_SYMBOL(sparc64_get_clock_tick);
649 
650 #ifdef CONFIG_CPU_FREQ
651 
652 static int sparc64_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
653 				    void *data)
654 {
655 	struct cpufreq_freqs *freq = data;
656 	unsigned int cpu = freq->cpu;
657 	struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
658 
659 	if (!ft->ref_freq) {
660 		ft->ref_freq = freq->old;
661 		ft->clock_tick_ref = cpu_data(cpu).clock_tick;
662 	}
663 	if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
664 	    (val == CPUFREQ_POSTCHANGE && freq->old > freq->new)) {
665 		cpu_data(cpu).clock_tick =
666 			cpufreq_scale(ft->clock_tick_ref,
667 				      ft->ref_freq,
668 				      freq->new);
669 	}
670 
671 	return 0;
672 }
673 
674 static struct notifier_block sparc64_cpufreq_notifier_block = {
675 	.notifier_call	= sparc64_cpufreq_notifier
676 };
677 
678 static int __init register_sparc64_cpufreq_notifier(void)
679 {
680 
681 	cpufreq_register_notifier(&sparc64_cpufreq_notifier_block,
682 				  CPUFREQ_TRANSITION_NOTIFIER);
683 	return 0;
684 }
685 
686 core_initcall(register_sparc64_cpufreq_notifier);
687 
688 #endif /* CONFIG_CPU_FREQ */
689 
690 static int sparc64_next_event(unsigned long delta,
691 			      struct clock_event_device *evt)
692 {
693 	return tick_operations.add_compare(delta) ? -ETIME : 0;
694 }
695 
696 static int sparc64_timer_shutdown(struct clock_event_device *evt)
697 {
698 	tick_operations.disable_irq();
699 	return 0;
700 }
701 
702 static struct clock_event_device sparc64_clockevent = {
703 	.features		= CLOCK_EVT_FEAT_ONESHOT,
704 	.set_state_shutdown	= sparc64_timer_shutdown,
705 	.set_next_event		= sparc64_next_event,
706 	.rating			= 100,
707 	.shift			= 30,
708 	.irq			= -1,
709 };
710 static DEFINE_PER_CPU(struct clock_event_device, sparc64_events);
711 
712 void __irq_entry timer_interrupt(int irq, struct pt_regs *regs)
713 {
714 	struct pt_regs *old_regs = set_irq_regs(regs);
715 	unsigned long tick_mask = tick_operations.softint_mask;
716 	int cpu = smp_processor_id();
717 	struct clock_event_device *evt = &per_cpu(sparc64_events, cpu);
718 
719 	clear_softint(tick_mask);
720 
721 	irq_enter();
722 
723 	local_cpu_data().irq0_irqs++;
724 	kstat_incr_irq_this_cpu(0);
725 
726 	if (unlikely(!evt->event_handler)) {
727 		printk(KERN_WARNING
728 		       "Spurious SPARC64 timer interrupt on cpu %d\n", cpu);
729 	} else
730 		evt->event_handler(evt);
731 
732 	irq_exit();
733 
734 	set_irq_regs(old_regs);
735 }
736 
737 void setup_sparc64_timer(void)
738 {
739 	struct clock_event_device *sevt;
740 	unsigned long pstate;
741 
742 	/* Guarantee that the following sequences execute
743 	 * uninterrupted.
744 	 */
745 	__asm__ __volatile__("rdpr	%%pstate, %0\n\t"
746 			     "wrpr	%0, %1, %%pstate"
747 			     : "=r" (pstate)
748 			     : "i" (PSTATE_IE));
749 
750 	tick_operations.init_tick();
751 
752 	/* Restore PSTATE_IE. */
753 	__asm__ __volatile__("wrpr	%0, 0x0, %%pstate"
754 			     : /* no outputs */
755 			     : "r" (pstate));
756 
757 	sevt = this_cpu_ptr(&sparc64_events);
758 
759 	memcpy(sevt, &sparc64_clockevent, sizeof(*sevt));
760 	sevt->cpumask = cpumask_of(smp_processor_id());
761 
762 	clockevents_register_device(sevt);
763 }
764 
765 #define SPARC64_NSEC_PER_CYC_SHIFT	10UL
766 
767 static struct clocksource clocksource_tick = {
768 	.rating		= 100,
769 	.mask		= CLOCKSOURCE_MASK(64),
770 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
771 };
772 
773 static unsigned long tb_ticks_per_usec __read_mostly;
774 
775 void __delay(unsigned long loops)
776 {
777 	unsigned long bclock = get_tick();
778 
779 	while ((get_tick() - bclock) < loops)
780 		;
781 }
782 EXPORT_SYMBOL(__delay);
783 
784 void udelay(unsigned long usecs)
785 {
786 	__delay(tb_ticks_per_usec * usecs);
787 }
788 EXPORT_SYMBOL(udelay);
789 
790 static u64 clocksource_tick_read(struct clocksource *cs)
791 {
792 	return get_tick();
793 }
794 
795 static void __init get_tick_patch(void)
796 {
797 	unsigned int *addr, *instr, i;
798 	struct get_tick_patch *p;
799 
800 	if (tlb_type == spitfire && is_hummingbird())
801 		return;
802 
803 	for (p = &__get_tick_patch; p < &__get_tick_patch_end; p++) {
804 		instr = (tlb_type == spitfire) ? p->tick : p->stick;
805 		addr = (unsigned int *)(unsigned long)p->addr;
806 		for (i = 0; i < GET_TICK_NINSTR; i++) {
807 			addr[i] = instr[i];
808 			/* ensure that address is modified before flush */
809 			wmb();
810 			flushi(&addr[i]);
811 		}
812 	}
813 }
814 
815 static void __init init_tick_ops(struct sparc64_tick_ops *ops)
816 {
817 	unsigned long freq, quotient, tick;
818 
819 	freq = ops->get_frequency();
820 	quotient = clocksource_hz2mult(freq, SPARC64_NSEC_PER_CYC_SHIFT);
821 	tick = ops->get_tick();
822 
823 	ops->offset = (tick * quotient) >> SPARC64_NSEC_PER_CYC_SHIFT;
824 	ops->ticks_per_nsec_quotient = quotient;
825 	ops->frequency = freq;
826 	tick_operations = *ops;
827 	get_tick_patch();
828 }
829 
830 void __init time_init_early(void)
831 {
832 	if (tlb_type == spitfire) {
833 		if (is_hummingbird()) {
834 			init_tick_ops(&hbtick_operations);
835 			clocksource_tick.archdata.vclock_mode = VCLOCK_NONE;
836 		} else {
837 			init_tick_ops(&tick_operations);
838 			clocksource_tick.archdata.vclock_mode = VCLOCK_TICK;
839 		}
840 	} else {
841 		init_tick_ops(&stick_operations);
842 		clocksource_tick.archdata.vclock_mode = VCLOCK_STICK;
843 	}
844 }
845 
846 void __init time_init(void)
847 {
848 	unsigned long freq;
849 
850 	freq = tick_operations.frequency;
851 	tb_ticks_per_usec = freq / USEC_PER_SEC;
852 
853 	clocksource_tick.name = tick_operations.name;
854 	clocksource_tick.read = clocksource_tick_read;
855 
856 	clocksource_register_hz(&clocksource_tick, freq);
857 	printk("clocksource: mult[%x] shift[%d]\n",
858 	       clocksource_tick.mult, clocksource_tick.shift);
859 
860 	sparc64_clockevent.name = tick_operations.name;
861 	clockevents_calc_mult_shift(&sparc64_clockevent, freq, 4);
862 
863 	sparc64_clockevent.max_delta_ns =
864 		clockevent_delta2ns(0x7fffffffffffffffUL, &sparc64_clockevent);
865 	sparc64_clockevent.max_delta_ticks = 0x7fffffffffffffffUL;
866 	sparc64_clockevent.min_delta_ns =
867 		clockevent_delta2ns(0xF, &sparc64_clockevent);
868 	sparc64_clockevent.min_delta_ticks = 0xF;
869 
870 	printk("clockevent: mult[%x] shift[%d]\n",
871 	       sparc64_clockevent.mult, sparc64_clockevent.shift);
872 
873 	setup_sparc64_timer();
874 }
875 
876 unsigned long long sched_clock(void)
877 {
878 	unsigned long quotient = tick_operations.ticks_per_nsec_quotient;
879 	unsigned long offset = tick_operations.offset;
880 
881 	/* Use barrier so the compiler emits the loads first and overlaps load
882 	 * latency with reading tick, because reading %tick/%stick is a
883 	 * post-sync instruction that will flush and restart subsequent
884 	 * instructions after it commits.
885 	 */
886 	barrier();
887 
888 	return ((get_tick() * quotient) >> SPARC64_NSEC_PER_CYC_SHIFT) - offset;
889 }
890 
891 int read_current_timer(unsigned long *timer_val)
892 {
893 	*timer_val = get_tick();
894 	return 0;
895 }
896