xref: /linux/arch/sparc/kernel/time_64.c (revision 6e7fd890f1d6ac83805409e9c346240de2705584)
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/sched/clock.h>
37 #include <linux/ftrace.h>
38 
39 #include <asm/oplib.h>
40 #include <asm/timer.h>
41 #include <asm/irq.h>
42 #include <asm/io.h>
43 #include <asm/prom.h>
44 #include <asm/starfire.h>
45 #include <asm/smp.h>
46 #include <asm/sections.h>
47 #include <asm/cpudata.h>
48 #include <linux/uaccess.h>
49 #include <asm/irq_regs.h>
50 #include <asm/cacheflush.h>
51 
52 #include "entry.h"
53 #include "kernel.h"
54 
55 DEFINE_SPINLOCK(rtc_lock);
56 
57 #ifdef CONFIG_SMP
58 unsigned long profile_pc(struct pt_regs *regs)
59 {
60 	unsigned long pc = instruction_pointer(regs);
61 
62 	if (in_lock_functions(pc))
63 		return regs->u_regs[UREG_RETPC];
64 	return pc;
65 }
66 EXPORT_SYMBOL(profile_pc);
67 #endif
68 
69 static void tick_disable_protection(void)
70 {
71 	/* Set things up so user can access tick register for profiling
72 	 * purposes.  Also workaround BB_ERRATA_1 by doing a dummy
73 	 * read back of %tick after writing it.
74 	 */
75 	__asm__ __volatile__(
76 	"	ba,pt	%%xcc, 1f\n"
77 	"	 nop\n"
78 	"	.align	64\n"
79 	"1:	rd	%%tick, %%g2\n"
80 	"	add	%%g2, 6, %%g2\n"
81 	"	andn	%%g2, %0, %%g2\n"
82 	"	wrpr	%%g2, 0, %%tick\n"
83 	"	rdpr	%%tick, %%g0"
84 	: /* no outputs */
85 	: "r" (TICK_PRIV_BIT)
86 	: "g2");
87 }
88 
89 static void tick_disable_irq(void)
90 {
91 	__asm__ __volatile__(
92 	"	ba,pt	%%xcc, 1f\n"
93 	"	 nop\n"
94 	"	.align	64\n"
95 	"1:	wr	%0, 0x0, %%tick_cmpr\n"
96 	"	rd	%%tick_cmpr, %%g0"
97 	: /* no outputs */
98 	: "r" (TICKCMP_IRQ_BIT));
99 }
100 
101 static void tick_init_tick(void)
102 {
103 	tick_disable_protection();
104 	tick_disable_irq();
105 }
106 
107 static unsigned long long tick_get_tick(void)
108 {
109 	unsigned long ret;
110 
111 	__asm__ __volatile__("rd	%%tick, %0\n\t"
112 			     "mov	%0, %0"
113 			     : "=r" (ret));
114 
115 	return ret & ~TICK_PRIV_BIT;
116 }
117 
118 static int tick_add_compare(unsigned long adj)
119 {
120 	unsigned long orig_tick, new_tick, new_compare;
121 
122 	__asm__ __volatile__("rd	%%tick, %0"
123 			     : "=r" (orig_tick));
124 
125 	orig_tick &= ~TICKCMP_IRQ_BIT;
126 
127 	/* Workaround for Spitfire Errata (#54 I think??), I discovered
128 	 * this via Sun BugID 4008234, mentioned in Solaris-2.5.1 patch
129 	 * number 103640.
130 	 *
131 	 * On Blackbird writes to %tick_cmpr can fail, the
132 	 * workaround seems to be to execute the wr instruction
133 	 * at the start of an I-cache line, and perform a dummy
134 	 * read back from %tick_cmpr right after writing to it. -DaveM
135 	 */
136 	__asm__ __volatile__("ba,pt	%%xcc, 1f\n\t"
137 			     " add	%1, %2, %0\n\t"
138 			     ".align	64\n"
139 			     "1:\n\t"
140 			     "wr	%0, 0, %%tick_cmpr\n\t"
141 			     "rd	%%tick_cmpr, %%g0\n\t"
142 			     : "=r" (new_compare)
143 			     : "r" (orig_tick), "r" (adj));
144 
145 	__asm__ __volatile__("rd	%%tick, %0"
146 			     : "=r" (new_tick));
147 	new_tick &= ~TICKCMP_IRQ_BIT;
148 
149 	return ((long)(new_tick - (orig_tick+adj))) > 0L;
150 }
151 
152 static unsigned long tick_add_tick(unsigned long adj)
153 {
154 	unsigned long new_tick;
155 
156 	/* Also need to handle Blackbird bug here too. */
157 	__asm__ __volatile__("rd	%%tick, %0\n\t"
158 			     "add	%0, %1, %0\n\t"
159 			     "wrpr	%0, 0, %%tick\n\t"
160 			     : "=&r" (new_tick)
161 			     : "r" (adj));
162 
163 	return new_tick;
164 }
165 
166 /* Searches for cpu clock frequency with given cpuid in OpenBoot tree */
167 static unsigned long cpuid_to_freq(phandle node, int cpuid)
168 {
169 	bool is_cpu_node = false;
170 	unsigned long freq = 0;
171 	char type[128];
172 
173 	if (!node)
174 		return freq;
175 
176 	if (prom_getproperty(node, "device_type", type, sizeof(type)) != -1)
177 		is_cpu_node = (strcmp(type, "cpu") == 0);
178 
179 	/* try upa-portid then cpuid to get cpuid, see prom_64.c */
180 	if (is_cpu_node && (prom_getint(node, "upa-portid") == cpuid ||
181 			    prom_getint(node, "cpuid") == cpuid))
182 		freq = prom_getintdefault(node, "clock-frequency", 0);
183 	if (!freq)
184 		freq = cpuid_to_freq(prom_getchild(node), cpuid);
185 	if (!freq)
186 		freq = cpuid_to_freq(prom_getsibling(node), cpuid);
187 
188 	return freq;
189 }
190 
191 static unsigned long tick_get_frequency(void)
192 {
193 	return cpuid_to_freq(prom_root_node, hard_smp_processor_id());
194 }
195 
196 static struct sparc64_tick_ops tick_operations __cacheline_aligned = {
197 	.name		=	"tick",
198 	.init_tick	=	tick_init_tick,
199 	.disable_irq	=	tick_disable_irq,
200 	.get_tick	=	tick_get_tick,
201 	.add_tick	=	tick_add_tick,
202 	.add_compare	=	tick_add_compare,
203 	.get_frequency	=	tick_get_frequency,
204 	.softint_mask	=	1UL << 0,
205 };
206 
207 struct sparc64_tick_ops *tick_ops __read_mostly = &tick_operations;
208 EXPORT_SYMBOL(tick_ops);
209 
210 static void stick_disable_irq(void)
211 {
212 	__asm__ __volatile__(
213 	"wr	%0, 0x0, %%asr25"
214 	: /* no outputs */
215 	: "r" (TICKCMP_IRQ_BIT));
216 }
217 
218 static void stick_init_tick(void)
219 {
220 	/* Writes to the %tick and %stick register are not
221 	 * allowed on sun4v.  The Hypervisor controls that
222 	 * bit, per-strand.
223 	 */
224 	if (tlb_type != hypervisor) {
225 		tick_disable_protection();
226 		tick_disable_irq();
227 
228 		/* Let the user get at STICK too. */
229 		__asm__ __volatile__(
230 		"	rd	%%asr24, %%g2\n"
231 		"	andn	%%g2, %0, %%g2\n"
232 		"	wr	%%g2, 0, %%asr24"
233 		: /* no outputs */
234 		: "r" (TICK_PRIV_BIT)
235 		: "g1", "g2");
236 	}
237 
238 	stick_disable_irq();
239 }
240 
241 static unsigned long long stick_get_tick(void)
242 {
243 	unsigned long ret;
244 
245 	__asm__ __volatile__("rd	%%asr24, %0"
246 			     : "=r" (ret));
247 
248 	return ret & ~TICK_PRIV_BIT;
249 }
250 
251 static unsigned long stick_add_tick(unsigned long adj)
252 {
253 	unsigned long new_tick;
254 
255 	__asm__ __volatile__("rd	%%asr24, %0\n\t"
256 			     "add	%0, %1, %0\n\t"
257 			     "wr	%0, 0, %%asr24\n\t"
258 			     : "=&r" (new_tick)
259 			     : "r" (adj));
260 
261 	return new_tick;
262 }
263 
264 static int stick_add_compare(unsigned long adj)
265 {
266 	unsigned long orig_tick, new_tick;
267 
268 	__asm__ __volatile__("rd	%%asr24, %0"
269 			     : "=r" (orig_tick));
270 	orig_tick &= ~TICKCMP_IRQ_BIT;
271 
272 	__asm__ __volatile__("wr	%0, 0, %%asr25"
273 			     : /* no outputs */
274 			     : "r" (orig_tick + adj));
275 
276 	__asm__ __volatile__("rd	%%asr24, %0"
277 			     : "=r" (new_tick));
278 	new_tick &= ~TICKCMP_IRQ_BIT;
279 
280 	return ((long)(new_tick - (orig_tick+adj))) > 0L;
281 }
282 
283 static unsigned long stick_get_frequency(void)
284 {
285 	return prom_getintdefault(prom_root_node, "stick-frequency", 0);
286 }
287 
288 static struct sparc64_tick_ops stick_operations __read_mostly = {
289 	.name		=	"stick",
290 	.init_tick	=	stick_init_tick,
291 	.disable_irq	=	stick_disable_irq,
292 	.get_tick	=	stick_get_tick,
293 	.add_tick	=	stick_add_tick,
294 	.add_compare	=	stick_add_compare,
295 	.get_frequency	=	stick_get_frequency,
296 	.softint_mask	=	1UL << 16,
297 };
298 
299 /* On Hummingbird the STICK/STICK_CMPR register is implemented
300  * in I/O space.  There are two 64-bit registers each, the
301  * first holds the low 32-bits of the value and the second holds
302  * the high 32-bits.
303  *
304  * Since STICK is constantly updating, we have to access it carefully.
305  *
306  * The sequence we use to read is:
307  * 1) read high
308  * 2) read low
309  * 3) read high again, if it rolled re-read both low and high again.
310  *
311  * Writing STICK safely is also tricky:
312  * 1) write low to zero
313  * 2) write high
314  * 3) write low
315  */
316 static unsigned long __hbird_read_stick(void)
317 {
318 	unsigned long ret, tmp1, tmp2, tmp3;
319 	unsigned long addr = HBIRD_STICK_ADDR+8;
320 
321 	__asm__ __volatile__("ldxa	[%1] %5, %2\n"
322 			     "1:\n\t"
323 			     "sub	%1, 0x8, %1\n\t"
324 			     "ldxa	[%1] %5, %3\n\t"
325 			     "add	%1, 0x8, %1\n\t"
326 			     "ldxa	[%1] %5, %4\n\t"
327 			     "cmp	%4, %2\n\t"
328 			     "bne,a,pn	%%xcc, 1b\n\t"
329 			     " mov	%4, %2\n\t"
330 			     "sllx	%4, 32, %4\n\t"
331 			     "or	%3, %4, %0\n\t"
332 			     : "=&r" (ret), "=&r" (addr),
333 			       "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3)
334 			     : "i" (ASI_PHYS_BYPASS_EC_E), "1" (addr));
335 
336 	return ret;
337 }
338 
339 static void __hbird_write_stick(unsigned long val)
340 {
341 	unsigned long low = (val & 0xffffffffUL);
342 	unsigned long high = (val >> 32UL);
343 	unsigned long addr = HBIRD_STICK_ADDR;
344 
345 	__asm__ __volatile__("stxa	%%g0, [%0] %4\n\t"
346 			     "add	%0, 0x8, %0\n\t"
347 			     "stxa	%3, [%0] %4\n\t"
348 			     "sub	%0, 0x8, %0\n\t"
349 			     "stxa	%2, [%0] %4"
350 			     : "=&r" (addr)
351 			     : "0" (addr), "r" (low), "r" (high),
352 			       "i" (ASI_PHYS_BYPASS_EC_E));
353 }
354 
355 static void __hbird_write_compare(unsigned long val)
356 {
357 	unsigned long low = (val & 0xffffffffUL);
358 	unsigned long high = (val >> 32UL);
359 	unsigned long addr = HBIRD_STICKCMP_ADDR + 0x8UL;
360 
361 	__asm__ __volatile__("stxa	%3, [%0] %4\n\t"
362 			     "sub	%0, 0x8, %0\n\t"
363 			     "stxa	%2, [%0] %4"
364 			     : "=&r" (addr)
365 			     : "0" (addr), "r" (low), "r" (high),
366 			       "i" (ASI_PHYS_BYPASS_EC_E));
367 }
368 
369 static void hbtick_disable_irq(void)
370 {
371 	__hbird_write_compare(TICKCMP_IRQ_BIT);
372 }
373 
374 static void hbtick_init_tick(void)
375 {
376 	tick_disable_protection();
377 
378 	/* XXX This seems to be necessary to 'jumpstart' Hummingbird
379 	 * XXX into actually sending STICK interrupts.  I think because
380 	 * XXX of how we store %tick_cmpr in head.S this somehow resets the
381 	 * XXX {TICK + STICK} interrupt mux.  -DaveM
382 	 */
383 	__hbird_write_stick(__hbird_read_stick());
384 
385 	hbtick_disable_irq();
386 }
387 
388 static unsigned long long hbtick_get_tick(void)
389 {
390 	return __hbird_read_stick() & ~TICK_PRIV_BIT;
391 }
392 
393 static unsigned long hbtick_add_tick(unsigned long adj)
394 {
395 	unsigned long val;
396 
397 	val = __hbird_read_stick() + adj;
398 	__hbird_write_stick(val);
399 
400 	return val;
401 }
402 
403 static int hbtick_add_compare(unsigned long adj)
404 {
405 	unsigned long val = __hbird_read_stick();
406 	unsigned long val2;
407 
408 	val &= ~TICKCMP_IRQ_BIT;
409 	val += adj;
410 	__hbird_write_compare(val);
411 
412 	val2 = __hbird_read_stick() & ~TICKCMP_IRQ_BIT;
413 
414 	return ((long)(val2 - val)) > 0L;
415 }
416 
417 static unsigned long hbtick_get_frequency(void)
418 {
419 	return prom_getintdefault(prom_root_node, "stick-frequency", 0);
420 }
421 
422 static struct sparc64_tick_ops hbtick_operations __read_mostly = {
423 	.name		=	"hbtick",
424 	.init_tick	=	hbtick_init_tick,
425 	.disable_irq	=	hbtick_disable_irq,
426 	.get_tick	=	hbtick_get_tick,
427 	.add_tick	=	hbtick_add_tick,
428 	.add_compare	=	hbtick_add_compare,
429 	.get_frequency	=	hbtick_get_frequency,
430 	.softint_mask	=	1UL << 0,
431 };
432 
433 unsigned long cmos_regs;
434 EXPORT_SYMBOL(cmos_regs);
435 
436 static struct resource rtc_cmos_resource;
437 
438 static struct platform_device rtc_cmos_device = {
439 	.name		= "rtc_cmos",
440 	.id		= -1,
441 	.resource	= &rtc_cmos_resource,
442 	.num_resources	= 1,
443 };
444 
445 static int rtc_probe(struct platform_device *op)
446 {
447 	struct resource *r;
448 
449 	printk(KERN_INFO "%pOF: RTC regs at 0x%llx\n",
450 	       op->dev.of_node, op->resource[0].start);
451 
452 	/* The CMOS RTC driver only accepts IORESOURCE_IO, so cons
453 	 * up a fake resource so that the probe works for all cases.
454 	 * When the RTC is behind an ISA bus it will have IORESOURCE_IO
455 	 * already, whereas when it's behind EBUS is will be IORESOURCE_MEM.
456 	 */
457 
458 	r = &rtc_cmos_resource;
459 	r->flags = IORESOURCE_IO;
460 	r->name = op->resource[0].name;
461 	r->start = op->resource[0].start;
462 	r->end = op->resource[0].end;
463 
464 	cmos_regs = op->resource[0].start;
465 	return platform_device_register(&rtc_cmos_device);
466 }
467 
468 static const struct of_device_id rtc_match[] = {
469 	{
470 		.name = "rtc",
471 		.compatible = "m5819",
472 	},
473 	{
474 		.name = "rtc",
475 		.compatible = "isa-m5819p",
476 	},
477 	{
478 		.name = "rtc",
479 		.compatible = "isa-m5823p",
480 	},
481 	{
482 		.name = "rtc",
483 		.compatible = "ds1287",
484 	},
485 	{},
486 };
487 
488 static struct platform_driver rtc_driver = {
489 	.probe		= rtc_probe,
490 	.driver = {
491 		.name = "rtc",
492 		.of_match_table = rtc_match,
493 	},
494 };
495 
496 static struct platform_device rtc_bq4802_device = {
497 	.name		= "rtc-bq4802",
498 	.id		= -1,
499 	.num_resources	= 1,
500 };
501 
502 static int bq4802_probe(struct platform_device *op)
503 {
504 
505 	printk(KERN_INFO "%pOF: BQ4802 regs at 0x%llx\n",
506 	       op->dev.of_node, op->resource[0].start);
507 
508 	rtc_bq4802_device.resource = &op->resource[0];
509 	return platform_device_register(&rtc_bq4802_device);
510 }
511 
512 static const struct of_device_id bq4802_match[] = {
513 	{
514 		.name = "rtc",
515 		.compatible = "bq4802",
516 	},
517 	{},
518 };
519 
520 static struct platform_driver bq4802_driver = {
521 	.probe		= bq4802_probe,
522 	.driver = {
523 		.name = "bq4802",
524 		.of_match_table = bq4802_match,
525 	},
526 };
527 
528 static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
529 {
530 	struct platform_device *pdev = to_platform_device(dev);
531 	void __iomem *regs = (void __iomem *) pdev->resource[0].start;
532 
533 	return readb(regs + ofs);
534 }
535 
536 static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
537 {
538 	struct platform_device *pdev = to_platform_device(dev);
539 	void __iomem *regs = (void __iomem *) pdev->resource[0].start;
540 
541 	writeb(val, regs + ofs);
542 }
543 
544 static struct m48t59_plat_data m48t59_data = {
545 	.read_byte	= mostek_read_byte,
546 	.write_byte	= mostek_write_byte,
547 };
548 
549 static struct platform_device m48t59_rtc = {
550 	.name		= "rtc-m48t59",
551 	.id		= 0,
552 	.num_resources	= 1,
553 	.dev	= {
554 		.platform_data = &m48t59_data,
555 	},
556 };
557 
558 static int mostek_probe(struct platform_device *op)
559 {
560 	struct device_node *dp = op->dev.of_node;
561 
562 	/* On an Enterprise system there can be multiple mostek clocks.
563 	 * We should only match the one that is on the central FHC bus.
564 	 */
565 	if (of_node_name_eq(dp->parent, "fhc") &&
566 	    !of_node_name_eq(dp->parent->parent, "central"))
567 		return -ENODEV;
568 
569 	printk(KERN_INFO "%pOF: Mostek regs at 0x%llx\n",
570 	       dp, op->resource[0].start);
571 
572 	m48t59_rtc.resource = &op->resource[0];
573 	return platform_device_register(&m48t59_rtc);
574 }
575 
576 static const struct of_device_id mostek_match[] = {
577 	{
578 		.name = "eeprom",
579 	},
580 	{},
581 };
582 
583 static struct platform_driver mostek_driver = {
584 	.probe		= mostek_probe,
585 	.driver = {
586 		.name = "mostek",
587 		.of_match_table = mostek_match,
588 	},
589 };
590 
591 static struct platform_device rtc_sun4v_device = {
592 	.name		= "rtc-sun4v",
593 	.id		= -1,
594 };
595 
596 static struct platform_device rtc_starfire_device = {
597 	.name		= "rtc-starfire",
598 	.id		= -1,
599 };
600 
601 static int __init clock_init(void)
602 {
603 	if (this_is_starfire)
604 		return platform_device_register(&rtc_starfire_device);
605 
606 	if (tlb_type == hypervisor)
607 		return platform_device_register(&rtc_sun4v_device);
608 
609 	(void) platform_driver_register(&rtc_driver);
610 	(void) platform_driver_register(&mostek_driver);
611 	(void) platform_driver_register(&bq4802_driver);
612 
613 	return 0;
614 }
615 
616 /* Must be after subsys_initcall() so that busses are probed.  Must
617  * be before device_initcall() because things like the RTC driver
618  * need to see the clock registers.
619  */
620 fs_initcall(clock_init);
621 
622 /* Return true if this is Hummingbird, aka Ultra-IIe */
623 static bool is_hummingbird(void)
624 {
625 	unsigned long ver, manuf, impl;
626 
627 	__asm__ __volatile__ ("rdpr %%ver, %0"
628 			      : "=&r" (ver));
629 	manuf = ((ver >> 48) & 0xffff);
630 	impl = ((ver >> 32) & 0xffff);
631 
632 	return (manuf == 0x17 && impl == 0x13);
633 }
634 
635 struct freq_table {
636 	unsigned long clock_tick_ref;
637 	unsigned int ref_freq;
638 };
639 static DEFINE_PER_CPU(struct freq_table, sparc64_freq_table) = { 0, 0 };
640 
641 unsigned long sparc64_get_clock_tick(unsigned int cpu)
642 {
643 	struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
644 
645 	if (ft->clock_tick_ref)
646 		return ft->clock_tick_ref;
647 	return cpu_data(cpu).clock_tick;
648 }
649 EXPORT_SYMBOL(sparc64_get_clock_tick);
650 
651 #ifdef CONFIG_CPU_FREQ
652 
653 static int sparc64_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
654 				    void *data)
655 {
656 	struct cpufreq_freqs *freq = data;
657 	unsigned int cpu;
658 	struct freq_table *ft;
659 
660 	for_each_cpu(cpu, freq->policy->cpus) {
661 		ft = &per_cpu(sparc64_freq_table, cpu);
662 
663 		if (!ft->ref_freq) {
664 			ft->ref_freq = freq->old;
665 			ft->clock_tick_ref = cpu_data(cpu).clock_tick;
666 		}
667 
668 		if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
669 		    (val == CPUFREQ_POSTCHANGE && freq->old > freq->new)) {
670 			cpu_data(cpu).clock_tick =
671 				cpufreq_scale(ft->clock_tick_ref, ft->ref_freq,
672 					      freq->new);
673 		}
674 	}
675 
676 	return 0;
677 }
678 
679 static struct notifier_block sparc64_cpufreq_notifier_block = {
680 	.notifier_call	= sparc64_cpufreq_notifier
681 };
682 
683 static int __init register_sparc64_cpufreq_notifier(void)
684 {
685 
686 	cpufreq_register_notifier(&sparc64_cpufreq_notifier_block,
687 				  CPUFREQ_TRANSITION_NOTIFIER);
688 	return 0;
689 }
690 
691 core_initcall(register_sparc64_cpufreq_notifier);
692 
693 #endif /* CONFIG_CPU_FREQ */
694 
695 static int sparc64_next_event(unsigned long delta,
696 			      struct clock_event_device *evt)
697 {
698 	return tick_operations.add_compare(delta) ? -ETIME : 0;
699 }
700 
701 static int sparc64_timer_shutdown(struct clock_event_device *evt)
702 {
703 	tick_operations.disable_irq();
704 	return 0;
705 }
706 
707 static struct clock_event_device sparc64_clockevent = {
708 	.features		= CLOCK_EVT_FEAT_ONESHOT,
709 	.set_state_shutdown	= sparc64_timer_shutdown,
710 	.set_next_event		= sparc64_next_event,
711 	.rating			= 100,
712 	.shift			= 30,
713 	.irq			= -1,
714 };
715 static DEFINE_PER_CPU(struct clock_event_device, sparc64_events);
716 
717 void __irq_entry timer_interrupt(int irq, struct pt_regs *regs)
718 {
719 	struct pt_regs *old_regs = set_irq_regs(regs);
720 	unsigned long tick_mask = tick_operations.softint_mask;
721 	int cpu = smp_processor_id();
722 	struct clock_event_device *evt = &per_cpu(sparc64_events, cpu);
723 
724 	clear_softint(tick_mask);
725 
726 	irq_enter();
727 
728 	local_cpu_data().irq0_irqs++;
729 	kstat_incr_irq_this_cpu(0);
730 
731 	if (unlikely(!evt->event_handler)) {
732 		printk(KERN_WARNING
733 		       "Spurious SPARC64 timer interrupt on cpu %d\n", cpu);
734 	} else
735 		evt->event_handler(evt);
736 
737 	irq_exit();
738 
739 	set_irq_regs(old_regs);
740 }
741 
742 void setup_sparc64_timer(void)
743 {
744 	struct clock_event_device *sevt;
745 	unsigned long pstate;
746 
747 	/* Guarantee that the following sequences execute
748 	 * uninterrupted.
749 	 */
750 	__asm__ __volatile__("rdpr	%%pstate, %0\n\t"
751 			     "wrpr	%0, %1, %%pstate"
752 			     : "=r" (pstate)
753 			     : "i" (PSTATE_IE));
754 
755 	tick_operations.init_tick();
756 
757 	/* Restore PSTATE_IE. */
758 	__asm__ __volatile__("wrpr	%0, 0x0, %%pstate"
759 			     : /* no outputs */
760 			     : "r" (pstate));
761 
762 	sevt = this_cpu_ptr(&sparc64_events);
763 
764 	memcpy(sevt, &sparc64_clockevent, sizeof(*sevt));
765 	sevt->cpumask = cpumask_of(smp_processor_id());
766 
767 	clockevents_register_device(sevt);
768 }
769 
770 #define SPARC64_NSEC_PER_CYC_SHIFT	10UL
771 
772 static struct clocksource clocksource_tick = {
773 	.rating		= 100,
774 	.mask		= CLOCKSOURCE_MASK(64),
775 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
776 };
777 
778 static unsigned long tb_ticks_per_usec __read_mostly;
779 
780 void __delay(unsigned long loops)
781 {
782 	unsigned long bclock = get_tick();
783 
784 	while ((get_tick() - bclock) < loops)
785 		;
786 }
787 EXPORT_SYMBOL(__delay);
788 
789 void udelay(unsigned long usecs)
790 {
791 	__delay(tb_ticks_per_usec * usecs);
792 }
793 EXPORT_SYMBOL(udelay);
794 
795 static u64 clocksource_tick_read(struct clocksource *cs)
796 {
797 	return get_tick();
798 }
799 
800 static void __init get_tick_patch(void)
801 {
802 	unsigned int *addr, *instr, i;
803 	struct get_tick_patch *p;
804 
805 	if (tlb_type == spitfire && is_hummingbird())
806 		return;
807 
808 	for (p = &__get_tick_patch; p < &__get_tick_patch_end; p++) {
809 		instr = (tlb_type == spitfire) ? p->tick : p->stick;
810 		addr = (unsigned int *)(unsigned long)p->addr;
811 		for (i = 0; i < GET_TICK_NINSTR; i++) {
812 			addr[i] = instr[i];
813 			/* ensure that address is modified before flush */
814 			wmb();
815 			flushi(&addr[i]);
816 		}
817 	}
818 }
819 
820 static void __init init_tick_ops(struct sparc64_tick_ops *ops)
821 {
822 	unsigned long freq, quotient, tick;
823 
824 	freq = ops->get_frequency();
825 	quotient = clocksource_hz2mult(freq, SPARC64_NSEC_PER_CYC_SHIFT);
826 	tick = ops->get_tick();
827 
828 	ops->offset = (tick * quotient) >> SPARC64_NSEC_PER_CYC_SHIFT;
829 	ops->ticks_per_nsec_quotient = quotient;
830 	ops->frequency = freq;
831 	tick_operations = *ops;
832 	get_tick_patch();
833 }
834 
835 void __init time_init_early(void)
836 {
837 	if (tlb_type == spitfire) {
838 		if (is_hummingbird()) {
839 			init_tick_ops(&hbtick_operations);
840 			clocksource_tick.archdata.vclock_mode = VCLOCK_NONE;
841 		} else {
842 			init_tick_ops(&tick_operations);
843 			clocksource_tick.archdata.vclock_mode = VCLOCK_TICK;
844 		}
845 	} else {
846 		init_tick_ops(&stick_operations);
847 		clocksource_tick.archdata.vclock_mode = VCLOCK_STICK;
848 	}
849 }
850 
851 void __init time_init(void)
852 {
853 	unsigned long freq;
854 
855 	freq = tick_operations.frequency;
856 	tb_ticks_per_usec = freq / USEC_PER_SEC;
857 
858 	clocksource_tick.name = tick_operations.name;
859 	clocksource_tick.read = clocksource_tick_read;
860 
861 	clocksource_register_hz(&clocksource_tick, freq);
862 	printk("clocksource: mult[%x] shift[%d]\n",
863 	       clocksource_tick.mult, clocksource_tick.shift);
864 
865 	sparc64_clockevent.name = tick_operations.name;
866 	clockevents_calc_mult_shift(&sparc64_clockevent, freq, 4);
867 
868 	sparc64_clockevent.max_delta_ns =
869 		clockevent_delta2ns(0x7fffffffffffffffUL, &sparc64_clockevent);
870 	sparc64_clockevent.max_delta_ticks = 0x7fffffffffffffffUL;
871 	sparc64_clockevent.min_delta_ns =
872 		clockevent_delta2ns(0xF, &sparc64_clockevent);
873 	sparc64_clockevent.min_delta_ticks = 0xF;
874 
875 	printk("clockevent: mult[%x] shift[%d]\n",
876 	       sparc64_clockevent.mult, sparc64_clockevent.shift);
877 
878 	setup_sparc64_timer();
879 }
880 
881 unsigned long long sched_clock(void)
882 {
883 	unsigned long quotient = tick_operations.ticks_per_nsec_quotient;
884 	unsigned long offset = tick_operations.offset;
885 
886 	/* Use barrier so the compiler emits the loads first and overlaps load
887 	 * latency with reading tick, because reading %tick/%stick is a
888 	 * post-sync instruction that will flush and restart subsequent
889 	 * instructions after it commits.
890 	 */
891 	barrier();
892 
893 	return ((get_tick() * quotient) >> SPARC64_NSEC_PER_CYC_SHIFT) - offset;
894 }
895 
896 int read_current_timer(unsigned long *timer_val)
897 {
898 	*timer_val = get_tick();
899 	return 0;
900 }
901