xref: /openbmc/linux/arch/sparc/kernel/time_64.c (revision 82e6fdd6)
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 unsigned int __read_mostly vdso_fix_stick;
57 
58 #ifdef CONFIG_SMP
59 unsigned long profile_pc(struct pt_regs *regs)
60 {
61 	unsigned long pc = instruction_pointer(regs);
62 
63 	if (in_lock_functions(pc))
64 		return regs->u_regs[UREG_RETPC];
65 	return pc;
66 }
67 EXPORT_SYMBOL(profile_pc);
68 #endif
69 
70 static void tick_disable_protection(void)
71 {
72 	/* Set things up so user can access tick register for profiling
73 	 * purposes.  Also workaround BB_ERRATA_1 by doing a dummy
74 	 * read back of %tick after writing it.
75 	 */
76 	__asm__ __volatile__(
77 	"	ba,pt	%%xcc, 1f\n"
78 	"	 nop\n"
79 	"	.align	64\n"
80 	"1:	rd	%%tick, %%g2\n"
81 	"	add	%%g2, 6, %%g2\n"
82 	"	andn	%%g2, %0, %%g2\n"
83 	"	wrpr	%%g2, 0, %%tick\n"
84 	"	rdpr	%%tick, %%g0"
85 	: /* no outputs */
86 	: "r" (TICK_PRIV_BIT)
87 	: "g2");
88 }
89 
90 static void tick_disable_irq(void)
91 {
92 	__asm__ __volatile__(
93 	"	ba,pt	%%xcc, 1f\n"
94 	"	 nop\n"
95 	"	.align	64\n"
96 	"1:	wr	%0, 0x0, %%tick_cmpr\n"
97 	"	rd	%%tick_cmpr, %%g0"
98 	: /* no outputs */
99 	: "r" (TICKCMP_IRQ_BIT));
100 }
101 
102 static void tick_init_tick(void)
103 {
104 	tick_disable_protection();
105 	tick_disable_irq();
106 }
107 
108 static unsigned long long tick_get_tick(void)
109 {
110 	unsigned long ret;
111 
112 	__asm__ __volatile__("rd	%%tick, %0\n\t"
113 			     "mov	%0, %0"
114 			     : "=r" (ret));
115 
116 	return ret & ~TICK_PRIV_BIT;
117 }
118 
119 static int tick_add_compare(unsigned long adj)
120 {
121 	unsigned long orig_tick, new_tick, new_compare;
122 
123 	__asm__ __volatile__("rd	%%tick, %0"
124 			     : "=r" (orig_tick));
125 
126 	orig_tick &= ~TICKCMP_IRQ_BIT;
127 
128 	/* Workaround for Spitfire Errata (#54 I think??), I discovered
129 	 * this via Sun BugID 4008234, mentioned in Solaris-2.5.1 patch
130 	 * number 103640.
131 	 *
132 	 * On Blackbird writes to %tick_cmpr can fail, the
133 	 * workaround seems to be to execute the wr instruction
134 	 * at the start of an I-cache line, and perform a dummy
135 	 * read back from %tick_cmpr right after writing to it. -DaveM
136 	 */
137 	__asm__ __volatile__("ba,pt	%%xcc, 1f\n\t"
138 			     " add	%1, %2, %0\n\t"
139 			     ".align	64\n"
140 			     "1:\n\t"
141 			     "wr	%0, 0, %%tick_cmpr\n\t"
142 			     "rd	%%tick_cmpr, %%g0\n\t"
143 			     : "=r" (new_compare)
144 			     : "r" (orig_tick), "r" (adj));
145 
146 	__asm__ __volatile__("rd	%%tick, %0"
147 			     : "=r" (new_tick));
148 	new_tick &= ~TICKCMP_IRQ_BIT;
149 
150 	return ((long)(new_tick - (orig_tick+adj))) > 0L;
151 }
152 
153 static unsigned long tick_add_tick(unsigned long adj)
154 {
155 	unsigned long new_tick;
156 
157 	/* Also need to handle Blackbird bug here too. */
158 	__asm__ __volatile__("rd	%%tick, %0\n\t"
159 			     "add	%0, %1, %0\n\t"
160 			     "wrpr	%0, 0, %%tick\n\t"
161 			     : "=&r" (new_tick)
162 			     : "r" (adj));
163 
164 	return new_tick;
165 }
166 
167 /* Searches for cpu clock frequency with given cpuid in OpenBoot tree */
168 static unsigned long cpuid_to_freq(phandle node, int cpuid)
169 {
170 	bool is_cpu_node = false;
171 	unsigned long freq = 0;
172 	char type[128];
173 
174 	if (!node)
175 		return freq;
176 
177 	if (prom_getproperty(node, "device_type", type, sizeof(type)) != -1)
178 		is_cpu_node = (strcmp(type, "cpu") == 0);
179 
180 	/* try upa-portid then cpuid to get cpuid, see prom_64.c */
181 	if (is_cpu_node && (prom_getint(node, "upa-portid") == cpuid ||
182 			    prom_getint(node, "cpuid") == cpuid))
183 		freq = prom_getintdefault(node, "clock-frequency", 0);
184 	if (!freq)
185 		freq = cpuid_to_freq(prom_getchild(node), cpuid);
186 	if (!freq)
187 		freq = cpuid_to_freq(prom_getsibling(node), cpuid);
188 
189 	return freq;
190 }
191 
192 static unsigned long tick_get_frequency(void)
193 {
194 	return cpuid_to_freq(prom_root_node, hard_smp_processor_id());
195 }
196 
197 static struct sparc64_tick_ops tick_operations __cacheline_aligned = {
198 	.name		=	"tick",
199 	.init_tick	=	tick_init_tick,
200 	.disable_irq	=	tick_disable_irq,
201 	.get_tick	=	tick_get_tick,
202 	.add_tick	=	tick_add_tick,
203 	.add_compare	=	tick_add_compare,
204 	.get_frequency	=	tick_get_frequency,
205 	.softint_mask	=	1UL << 0,
206 };
207 
208 struct sparc64_tick_ops *tick_ops __read_mostly = &tick_operations;
209 EXPORT_SYMBOL(tick_ops);
210 
211 static void stick_disable_irq(void)
212 {
213 	__asm__ __volatile__(
214 	"wr	%0, 0x0, %%asr25"
215 	: /* no outputs */
216 	: "r" (TICKCMP_IRQ_BIT));
217 }
218 
219 static void stick_init_tick(void)
220 {
221 	/* Writes to the %tick and %stick register are not
222 	 * allowed on sun4v.  The Hypervisor controls that
223 	 * bit, per-strand.
224 	 */
225 	if (tlb_type != hypervisor) {
226 		tick_disable_protection();
227 		tick_disable_irq();
228 
229 		/* Let the user get at STICK too. */
230 		__asm__ __volatile__(
231 		"	rd	%%asr24, %%g2\n"
232 		"	andn	%%g2, %0, %%g2\n"
233 		"	wr	%%g2, 0, %%asr24"
234 		: /* no outputs */
235 		: "r" (TICK_PRIV_BIT)
236 		: "g1", "g2");
237 	}
238 
239 	stick_disable_irq();
240 }
241 
242 static unsigned long long stick_get_tick(void)
243 {
244 	unsigned long ret;
245 
246 	__asm__ __volatile__("rd	%%asr24, %0"
247 			     : "=r" (ret));
248 
249 	return ret & ~TICK_PRIV_BIT;
250 }
251 
252 static unsigned long stick_add_tick(unsigned long adj)
253 {
254 	unsigned long new_tick;
255 
256 	__asm__ __volatile__("rd	%%asr24, %0\n\t"
257 			     "add	%0, %1, %0\n\t"
258 			     "wr	%0, 0, %%asr24\n\t"
259 			     : "=&r" (new_tick)
260 			     : "r" (adj));
261 
262 	return new_tick;
263 }
264 
265 static int stick_add_compare(unsigned long adj)
266 {
267 	unsigned long orig_tick, new_tick;
268 
269 	__asm__ __volatile__("rd	%%asr24, %0"
270 			     : "=r" (orig_tick));
271 	orig_tick &= ~TICKCMP_IRQ_BIT;
272 
273 	__asm__ __volatile__("wr	%0, 0, %%asr25"
274 			     : /* no outputs */
275 			     : "r" (orig_tick + adj));
276 
277 	__asm__ __volatile__("rd	%%asr24, %0"
278 			     : "=r" (new_tick));
279 	new_tick &= ~TICKCMP_IRQ_BIT;
280 
281 	return ((long)(new_tick - (orig_tick+adj))) > 0L;
282 }
283 
284 static unsigned long stick_get_frequency(void)
285 {
286 	return prom_getintdefault(prom_root_node, "stick-frequency", 0);
287 }
288 
289 static struct sparc64_tick_ops stick_operations __read_mostly = {
290 	.name		=	"stick",
291 	.init_tick	=	stick_init_tick,
292 	.disable_irq	=	stick_disable_irq,
293 	.get_tick	=	stick_get_tick,
294 	.add_tick	=	stick_add_tick,
295 	.add_compare	=	stick_add_compare,
296 	.get_frequency	=	stick_get_frequency,
297 	.softint_mask	=	1UL << 16,
298 };
299 
300 /* On Hummingbird the STICK/STICK_CMPR register is implemented
301  * in I/O space.  There are two 64-bit registers each, the
302  * first holds the low 32-bits of the value and the second holds
303  * the high 32-bits.
304  *
305  * Since STICK is constantly updating, we have to access it carefully.
306  *
307  * The sequence we use to read is:
308  * 1) read high
309  * 2) read low
310  * 3) read high again, if it rolled re-read both low and high again.
311  *
312  * Writing STICK safely is also tricky:
313  * 1) write low to zero
314  * 2) write high
315  * 3) write low
316  */
317 static unsigned long __hbird_read_stick(void)
318 {
319 	unsigned long ret, tmp1, tmp2, tmp3;
320 	unsigned long addr = HBIRD_STICK_ADDR+8;
321 
322 	__asm__ __volatile__("ldxa	[%1] %5, %2\n"
323 			     "1:\n\t"
324 			     "sub	%1, 0x8, %1\n\t"
325 			     "ldxa	[%1] %5, %3\n\t"
326 			     "add	%1, 0x8, %1\n\t"
327 			     "ldxa	[%1] %5, %4\n\t"
328 			     "cmp	%4, %2\n\t"
329 			     "bne,a,pn	%%xcc, 1b\n\t"
330 			     " mov	%4, %2\n\t"
331 			     "sllx	%4, 32, %4\n\t"
332 			     "or	%3, %4, %0\n\t"
333 			     : "=&r" (ret), "=&r" (addr),
334 			       "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3)
335 			     : "i" (ASI_PHYS_BYPASS_EC_E), "1" (addr));
336 
337 	return ret;
338 }
339 
340 static void __hbird_write_stick(unsigned long val)
341 {
342 	unsigned long low = (val & 0xffffffffUL);
343 	unsigned long high = (val >> 32UL);
344 	unsigned long addr = HBIRD_STICK_ADDR;
345 
346 	__asm__ __volatile__("stxa	%%g0, [%0] %4\n\t"
347 			     "add	%0, 0x8, %0\n\t"
348 			     "stxa	%3, [%0] %4\n\t"
349 			     "sub	%0, 0x8, %0\n\t"
350 			     "stxa	%2, [%0] %4"
351 			     : "=&r" (addr)
352 			     : "0" (addr), "r" (low), "r" (high),
353 			       "i" (ASI_PHYS_BYPASS_EC_E));
354 }
355 
356 static void __hbird_write_compare(unsigned long val)
357 {
358 	unsigned long low = (val & 0xffffffffUL);
359 	unsigned long high = (val >> 32UL);
360 	unsigned long addr = HBIRD_STICKCMP_ADDR + 0x8UL;
361 
362 	__asm__ __volatile__("stxa	%3, [%0] %4\n\t"
363 			     "sub	%0, 0x8, %0\n\t"
364 			     "stxa	%2, [%0] %4"
365 			     : "=&r" (addr)
366 			     : "0" (addr), "r" (low), "r" (high),
367 			       "i" (ASI_PHYS_BYPASS_EC_E));
368 }
369 
370 static void hbtick_disable_irq(void)
371 {
372 	__hbird_write_compare(TICKCMP_IRQ_BIT);
373 }
374 
375 static void hbtick_init_tick(void)
376 {
377 	tick_disable_protection();
378 
379 	/* XXX This seems to be necessary to 'jumpstart' Hummingbird
380 	 * XXX into actually sending STICK interrupts.  I think because
381 	 * XXX of how we store %tick_cmpr in head.S this somehow resets the
382 	 * XXX {TICK + STICK} interrupt mux.  -DaveM
383 	 */
384 	__hbird_write_stick(__hbird_read_stick());
385 
386 	hbtick_disable_irq();
387 }
388 
389 static unsigned long long hbtick_get_tick(void)
390 {
391 	return __hbird_read_stick() & ~TICK_PRIV_BIT;
392 }
393 
394 static unsigned long hbtick_add_tick(unsigned long adj)
395 {
396 	unsigned long val;
397 
398 	val = __hbird_read_stick() + adj;
399 	__hbird_write_stick(val);
400 
401 	return val;
402 }
403 
404 static int hbtick_add_compare(unsigned long adj)
405 {
406 	unsigned long val = __hbird_read_stick();
407 	unsigned long val2;
408 
409 	val &= ~TICKCMP_IRQ_BIT;
410 	val += adj;
411 	__hbird_write_compare(val);
412 
413 	val2 = __hbird_read_stick() & ~TICKCMP_IRQ_BIT;
414 
415 	return ((long)(val2 - val)) > 0L;
416 }
417 
418 static unsigned long hbtick_get_frequency(void)
419 {
420 	return prom_getintdefault(prom_root_node, "stick-frequency", 0);
421 }
422 
423 static struct sparc64_tick_ops hbtick_operations __read_mostly = {
424 	.name		=	"hbtick",
425 	.init_tick	=	hbtick_init_tick,
426 	.disable_irq	=	hbtick_disable_irq,
427 	.get_tick	=	hbtick_get_tick,
428 	.add_tick	=	hbtick_add_tick,
429 	.add_compare	=	hbtick_add_compare,
430 	.get_frequency	=	hbtick_get_frequency,
431 	.softint_mask	=	1UL << 0,
432 };
433 
434 unsigned long cmos_regs;
435 EXPORT_SYMBOL(cmos_regs);
436 
437 static struct resource rtc_cmos_resource;
438 
439 static struct platform_device rtc_cmos_device = {
440 	.name		= "rtc_cmos",
441 	.id		= -1,
442 	.resource	= &rtc_cmos_resource,
443 	.num_resources	= 1,
444 };
445 
446 static int rtc_probe(struct platform_device *op)
447 {
448 	struct resource *r;
449 
450 	printk(KERN_INFO "%s: RTC regs at 0x%llx\n",
451 	       op->dev.of_node->full_name, op->resource[0].start);
452 
453 	/* The CMOS RTC driver only accepts IORESOURCE_IO, so cons
454 	 * up a fake resource so that the probe works for all cases.
455 	 * When the RTC is behind an ISA bus it will have IORESOURCE_IO
456 	 * already, whereas when it's behind EBUS is will be IORESOURCE_MEM.
457 	 */
458 
459 	r = &rtc_cmos_resource;
460 	r->flags = IORESOURCE_IO;
461 	r->name = op->resource[0].name;
462 	r->start = op->resource[0].start;
463 	r->end = op->resource[0].end;
464 
465 	cmos_regs = op->resource[0].start;
466 	return platform_device_register(&rtc_cmos_device);
467 }
468 
469 static const struct of_device_id rtc_match[] = {
470 	{
471 		.name = "rtc",
472 		.compatible = "m5819",
473 	},
474 	{
475 		.name = "rtc",
476 		.compatible = "isa-m5819p",
477 	},
478 	{
479 		.name = "rtc",
480 		.compatible = "isa-m5823p",
481 	},
482 	{
483 		.name = "rtc",
484 		.compatible = "ds1287",
485 	},
486 	{},
487 };
488 
489 static struct platform_driver rtc_driver = {
490 	.probe		= rtc_probe,
491 	.driver = {
492 		.name = "rtc",
493 		.of_match_table = rtc_match,
494 	},
495 };
496 
497 static struct platform_device rtc_bq4802_device = {
498 	.name		= "rtc-bq4802",
499 	.id		= -1,
500 	.num_resources	= 1,
501 };
502 
503 static int bq4802_probe(struct platform_device *op)
504 {
505 
506 	printk(KERN_INFO "%s: BQ4802 regs at 0x%llx\n",
507 	       op->dev.of_node->full_name, op->resource[0].start);
508 
509 	rtc_bq4802_device.resource = &op->resource[0];
510 	return platform_device_register(&rtc_bq4802_device);
511 }
512 
513 static const struct of_device_id bq4802_match[] = {
514 	{
515 		.name = "rtc",
516 		.compatible = "bq4802",
517 	},
518 	{},
519 };
520 
521 static struct platform_driver bq4802_driver = {
522 	.probe		= bq4802_probe,
523 	.driver = {
524 		.name = "bq4802",
525 		.of_match_table = bq4802_match,
526 	},
527 };
528 
529 static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
530 {
531 	struct platform_device *pdev = to_platform_device(dev);
532 	void __iomem *regs = (void __iomem *) pdev->resource[0].start;
533 
534 	return readb(regs + ofs);
535 }
536 
537 static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
538 {
539 	struct platform_device *pdev = to_platform_device(dev);
540 	void __iomem *regs = (void __iomem *) pdev->resource[0].start;
541 
542 	writeb(val, regs + ofs);
543 }
544 
545 static struct m48t59_plat_data m48t59_data = {
546 	.read_byte	= mostek_read_byte,
547 	.write_byte	= mostek_write_byte,
548 };
549 
550 static struct platform_device m48t59_rtc = {
551 	.name		= "rtc-m48t59",
552 	.id		= 0,
553 	.num_resources	= 1,
554 	.dev	= {
555 		.platform_data = &m48t59_data,
556 	},
557 };
558 
559 static int mostek_probe(struct platform_device *op)
560 {
561 	struct device_node *dp = op->dev.of_node;
562 
563 	/* On an Enterprise system there can be multiple mostek clocks.
564 	 * We should only match the one that is on the central FHC bus.
565 	 */
566 	if (!strcmp(dp->parent->name, "fhc") &&
567 	    strcmp(dp->parent->parent->name, "central") != 0)
568 		return -ENODEV;
569 
570 	printk(KERN_INFO "%s: Mostek regs at 0x%llx\n",
571 	       dp->full_name, op->resource[0].start);
572 
573 	m48t59_rtc.resource = &op->resource[0];
574 	return platform_device_register(&m48t59_rtc);
575 }
576 
577 static const struct of_device_id mostek_match[] = {
578 	{
579 		.name = "eeprom",
580 	},
581 	{},
582 };
583 
584 static struct platform_driver mostek_driver = {
585 	.probe		= mostek_probe,
586 	.driver = {
587 		.name = "mostek",
588 		.of_match_table = mostek_match,
589 	},
590 };
591 
592 static struct platform_device rtc_sun4v_device = {
593 	.name		= "rtc-sun4v",
594 	.id		= -1,
595 };
596 
597 static struct platform_device rtc_starfire_device = {
598 	.name		= "rtc-starfire",
599 	.id		= -1,
600 };
601 
602 static int __init clock_init(void)
603 {
604 	if (this_is_starfire)
605 		return platform_device_register(&rtc_starfire_device);
606 
607 	if (tlb_type == hypervisor)
608 		return platform_device_register(&rtc_sun4v_device);
609 
610 	(void) platform_driver_register(&rtc_driver);
611 	(void) platform_driver_register(&mostek_driver);
612 	(void) platform_driver_register(&bq4802_driver);
613 
614 	return 0;
615 }
616 
617 /* Must be after subsys_initcall() so that busses are probed.  Must
618  * be before device_initcall() because things like the RTC driver
619  * need to see the clock registers.
620  */
621 fs_initcall(clock_init);
622 
623 /* Return true if this is Hummingbird, aka Ultra-IIe */
624 static bool is_hummingbird(void)
625 {
626 	unsigned long ver, manuf, impl;
627 
628 	__asm__ __volatile__ ("rdpr %%ver, %0"
629 			      : "=&r" (ver));
630 	manuf = ((ver >> 48) & 0xffff);
631 	impl = ((ver >> 32) & 0xffff);
632 
633 	return (manuf == 0x17 && impl == 0x13);
634 }
635 
636 struct freq_table {
637 	unsigned long clock_tick_ref;
638 	unsigned int ref_freq;
639 };
640 static DEFINE_PER_CPU(struct freq_table, sparc64_freq_table) = { 0, 0 };
641 
642 unsigned long sparc64_get_clock_tick(unsigned int cpu)
643 {
644 	struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
645 
646 	if (ft->clock_tick_ref)
647 		return ft->clock_tick_ref;
648 	return cpu_data(cpu).clock_tick;
649 }
650 EXPORT_SYMBOL(sparc64_get_clock_tick);
651 
652 #ifdef CONFIG_CPU_FREQ
653 
654 static int sparc64_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
655 				    void *data)
656 {
657 	struct cpufreq_freqs *freq = data;
658 	unsigned int cpu = freq->cpu;
659 	struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
660 
661 	if (!ft->ref_freq) {
662 		ft->ref_freq = freq->old;
663 		ft->clock_tick_ref = cpu_data(cpu).clock_tick;
664 	}
665 	if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
666 	    (val == CPUFREQ_POSTCHANGE && freq->old > freq->new)) {
667 		cpu_data(cpu).clock_tick =
668 			cpufreq_scale(ft->clock_tick_ref,
669 				      ft->ref_freq,
670 				      freq->new);
671 	}
672 
673 	return 0;
674 }
675 
676 static struct notifier_block sparc64_cpufreq_notifier_block = {
677 	.notifier_call	= sparc64_cpufreq_notifier
678 };
679 
680 static int __init register_sparc64_cpufreq_notifier(void)
681 {
682 
683 	cpufreq_register_notifier(&sparc64_cpufreq_notifier_block,
684 				  CPUFREQ_TRANSITION_NOTIFIER);
685 	return 0;
686 }
687 
688 core_initcall(register_sparc64_cpufreq_notifier);
689 
690 #endif /* CONFIG_CPU_FREQ */
691 
692 static int sparc64_next_event(unsigned long delta,
693 			      struct clock_event_device *evt)
694 {
695 	return tick_operations.add_compare(delta) ? -ETIME : 0;
696 }
697 
698 static int sparc64_timer_shutdown(struct clock_event_device *evt)
699 {
700 	tick_operations.disable_irq();
701 	return 0;
702 }
703 
704 static struct clock_event_device sparc64_clockevent = {
705 	.features		= CLOCK_EVT_FEAT_ONESHOT,
706 	.set_state_shutdown	= sparc64_timer_shutdown,
707 	.set_next_event		= sparc64_next_event,
708 	.rating			= 100,
709 	.shift			= 30,
710 	.irq			= -1,
711 };
712 static DEFINE_PER_CPU(struct clock_event_device, sparc64_events);
713 
714 void __irq_entry timer_interrupt(int irq, struct pt_regs *regs)
715 {
716 	struct pt_regs *old_regs = set_irq_regs(regs);
717 	unsigned long tick_mask = tick_operations.softint_mask;
718 	int cpu = smp_processor_id();
719 	struct clock_event_device *evt = &per_cpu(sparc64_events, cpu);
720 
721 	clear_softint(tick_mask);
722 
723 	irq_enter();
724 
725 	local_cpu_data().irq0_irqs++;
726 	kstat_incr_irq_this_cpu(0);
727 
728 	if (unlikely(!evt->event_handler)) {
729 		printk(KERN_WARNING
730 		       "Spurious SPARC64 timer interrupt on cpu %d\n", cpu);
731 	} else
732 		evt->event_handler(evt);
733 
734 	irq_exit();
735 
736 	set_irq_regs(old_regs);
737 }
738 
739 void setup_sparc64_timer(void)
740 {
741 	struct clock_event_device *sevt;
742 	unsigned long pstate;
743 
744 	/* Guarantee that the following sequences execute
745 	 * uninterrupted.
746 	 */
747 	__asm__ __volatile__("rdpr	%%pstate, %0\n\t"
748 			     "wrpr	%0, %1, %%pstate"
749 			     : "=r" (pstate)
750 			     : "i" (PSTATE_IE));
751 
752 	tick_operations.init_tick();
753 
754 	/* Restore PSTATE_IE. */
755 	__asm__ __volatile__("wrpr	%0, 0x0, %%pstate"
756 			     : /* no outputs */
757 			     : "r" (pstate));
758 
759 	sevt = this_cpu_ptr(&sparc64_events);
760 
761 	memcpy(sevt, &sparc64_clockevent, sizeof(*sevt));
762 	sevt->cpumask = cpumask_of(smp_processor_id());
763 
764 	clockevents_register_device(sevt);
765 }
766 
767 #define SPARC64_NSEC_PER_CYC_SHIFT	10UL
768 
769 static struct clocksource clocksource_tick = {
770 	.rating		= 100,
771 	.mask		= CLOCKSOURCE_MASK(64),
772 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
773 };
774 
775 static unsigned long tb_ticks_per_usec __read_mostly;
776 
777 void __delay(unsigned long loops)
778 {
779 	unsigned long bclock = get_tick();
780 
781 	while ((get_tick() - bclock) < loops)
782 		;
783 }
784 EXPORT_SYMBOL(__delay);
785 
786 void udelay(unsigned long usecs)
787 {
788 	__delay(tb_ticks_per_usec * usecs);
789 }
790 EXPORT_SYMBOL(udelay);
791 
792 static u64 clocksource_tick_read(struct clocksource *cs)
793 {
794 	return get_tick();
795 }
796 
797 static void __init get_tick_patch(void)
798 {
799 	unsigned int *addr, *instr, i;
800 	struct get_tick_patch *p;
801 
802 	if (tlb_type == spitfire && is_hummingbird())
803 		return;
804 
805 	for (p = &__get_tick_patch; p < &__get_tick_patch_end; p++) {
806 		instr = (tlb_type == spitfire) ? p->tick : p->stick;
807 		addr = (unsigned int *)(unsigned long)p->addr;
808 		for (i = 0; i < GET_TICK_NINSTR; i++) {
809 			addr[i] = instr[i];
810 			/* ensure that address is modified before flush */
811 			wmb();
812 			flushi(&addr[i]);
813 		}
814 	}
815 }
816 
817 static void init_tick_ops(struct sparc64_tick_ops *ops)
818 {
819 	unsigned long freq, quotient, tick;
820 
821 	freq = ops->get_frequency();
822 	quotient = clocksource_hz2mult(freq, SPARC64_NSEC_PER_CYC_SHIFT);
823 	tick = ops->get_tick();
824 
825 	ops->offset = (tick * quotient) >> SPARC64_NSEC_PER_CYC_SHIFT;
826 	ops->ticks_per_nsec_quotient = quotient;
827 	ops->frequency = freq;
828 	tick_operations = *ops;
829 	get_tick_patch();
830 }
831 
832 void __init time_init_early(void)
833 {
834 	if (tlb_type == spitfire) {
835 		if (is_hummingbird()) {
836 			init_tick_ops(&hbtick_operations);
837 			clocksource_tick.archdata.vclock_mode = VCLOCK_NONE;
838 		} else {
839 			init_tick_ops(&tick_operations);
840 			clocksource_tick.archdata.vclock_mode = VCLOCK_TICK;
841 			vdso_fix_stick = 1;
842 		}
843 	} else {
844 		init_tick_ops(&stick_operations);
845 		clocksource_tick.archdata.vclock_mode = VCLOCK_STICK;
846 	}
847 }
848 
849 void __init time_init(void)
850 {
851 	unsigned long freq;
852 
853 	freq = tick_operations.frequency;
854 	tb_ticks_per_usec = freq / USEC_PER_SEC;
855 
856 	clocksource_tick.name = tick_operations.name;
857 	clocksource_tick.read = clocksource_tick_read;
858 
859 	clocksource_register_hz(&clocksource_tick, freq);
860 	printk("clocksource: mult[%x] shift[%d]\n",
861 	       clocksource_tick.mult, clocksource_tick.shift);
862 
863 	sparc64_clockevent.name = tick_operations.name;
864 	clockevents_calc_mult_shift(&sparc64_clockevent, freq, 4);
865 
866 	sparc64_clockevent.max_delta_ns =
867 		clockevent_delta2ns(0x7fffffffffffffffUL, &sparc64_clockevent);
868 	sparc64_clockevent.max_delta_ticks = 0x7fffffffffffffffUL;
869 	sparc64_clockevent.min_delta_ns =
870 		clockevent_delta2ns(0xF, &sparc64_clockevent);
871 	sparc64_clockevent.min_delta_ticks = 0xF;
872 
873 	printk("clockevent: mult[%x] shift[%d]\n",
874 	       sparc64_clockevent.mult, sparc64_clockevent.shift);
875 
876 	setup_sparc64_timer();
877 }
878 
879 unsigned long long sched_clock(void)
880 {
881 	unsigned long quotient = tick_operations.ticks_per_nsec_quotient;
882 	unsigned long offset = tick_operations.offset;
883 
884 	/* Use barrier so the compiler emits the loads first and overlaps load
885 	 * latency with reading tick, because reading %tick/%stick is a
886 	 * post-sync instruction that will flush and restart subsequent
887 	 * instructions after it commits.
888 	 */
889 	barrier();
890 
891 	return ((get_tick() * quotient) >> SPARC64_NSEC_PER_CYC_SHIFT) - offset;
892 }
893 
894 int read_current_timer(unsigned long *timer_val)
895 {
896 	*timer_val = get_tick();
897 	return 0;
898 }
899