1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/drivers/clocksource/arm_arch_timer.c
4 *
5 * Copyright (C) 2011 ARM Ltd.
6 * All Rights Reserved
7 */
8
9#define pr_fmt(fmt) "arch_timer: " fmt
10
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/device.h>
14#include <linux/smp.h>
15#include <linux/cpu.h>
16#include <linux/cpu_pm.h>
17#include <linux/clockchips.h>
18#include <linux/clocksource.h>
19#include <linux/clocksource_ids.h>
20#include <linux/interrupt.h>
21#include <linux/kstrtox.h>
22#include <linux/of_irq.h>
23#include <linux/of_address.h>
24#include <linux/io.h>
25#include <linux/slab.h>
26#include <linux/sched/clock.h>
27#include <linux/sched_clock.h>
28#include <linux/acpi.h>
29#include <linux/arm-smccc.h>
30#include <linux/ptp_kvm.h>
31
32#include <asm/arch_timer.h>
33#include <asm/virt.h>
34
35#include <clocksource/arm_arch_timer.h>
36
37#define CNTTIDR 0x08
38#define CNTTIDR_VIRT(n) (BIT(1) << ((n) * 4))
39
40#define CNTACR(n) (0x40 + ((n) * 4))
41#define CNTACR_RPCT BIT(0)
42#define CNTACR_RVCT BIT(1)
43#define CNTACR_RFRQ BIT(2)
44#define CNTACR_RVOFF BIT(3)
45#define CNTACR_RWVT BIT(4)
46#define CNTACR_RWPT BIT(5)
47
48#define CNTPCT_LO 0x00
49#define CNTVCT_LO 0x08
50#define CNTFRQ 0x10
51#define CNTP_CVAL_LO 0x20
52#define CNTP_CTL 0x2c
53#define CNTV_CVAL_LO 0x30
54#define CNTV_CTL 0x3c
55
56/*
57 * The minimum amount of time a generic counter is guaranteed to not roll over
58 * (40 years)
59 */
60#define MIN_ROLLOVER_SECS (40ULL * 365 * 24 * 3600)
61
62static unsigned arch_timers_present __initdata;
63
64struct arch_timer {
65 void __iomem *base;
66 struct clock_event_device evt;
67};
68
69static struct arch_timer *arch_timer_mem __ro_after_init;
70
71#define to_arch_timer(e) container_of(e, struct arch_timer, evt)
72
73static u32 arch_timer_rate __ro_after_init;
74static int arch_timer_ppi[ARCH_TIMER_MAX_TIMER_PPI] __ro_after_init;
75
76static const char *arch_timer_ppi_names[ARCH_TIMER_MAX_TIMER_PPI] = {
77 [ARCH_TIMER_PHYS_SECURE_PPI] = "sec-phys",
78 [ARCH_TIMER_PHYS_NONSECURE_PPI] = "phys",
79 [ARCH_TIMER_VIRT_PPI] = "virt",
80 [ARCH_TIMER_HYP_PPI] = "hyp-phys",
81 [ARCH_TIMER_HYP_VIRT_PPI] = "hyp-virt",
82};
83
84static struct clock_event_device __percpu *arch_timer_evt;
85
86static enum arch_timer_ppi_nr arch_timer_uses_ppi __ro_after_init = ARCH_TIMER_VIRT_PPI;
87static bool arch_timer_c3stop __ro_after_init;
88static bool arch_timer_mem_use_virtual __ro_after_init;
89static bool arch_counter_suspend_stop __ro_after_init;
90#ifdef CONFIG_GENERIC_GETTIMEOFDAY
91static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
92#else
93static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_NONE;
94#endif /* CONFIG_GENERIC_GETTIMEOFDAY */
95
96static cpumask_t evtstrm_available = CPU_MASK_NONE;
97static bool evtstrm_enable __ro_after_init = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM);
98
99static int __init early_evtstrm_cfg(char *buf)
100{
101 return kstrtobool(s: buf, res: &evtstrm_enable);
102}
103early_param("clocksource.arm_arch_timer.evtstrm", early_evtstrm_cfg);
104
105/*
106 * Makes an educated guess at a valid counter width based on the Generic Timer
107 * specification. Of note:
108 * 1) the system counter is at least 56 bits wide
109 * 2) a roll-over time of not less than 40 years
110 *
111 * See 'ARM DDI 0487G.a D11.1.2 ("The system counter")' for more details.
112 */
113static int arch_counter_get_width(void)
114{
115 u64 min_cycles = MIN_ROLLOVER_SECS * arch_timer_rate;
116
117 /* guarantee the returned width is within the valid range */
118 return clamp_val(ilog2(min_cycles - 1) + 1, 56, 64);
119}
120
121/*
122 * Architected system timer support.
123 */
124
125static __always_inline
126void arch_timer_reg_write(int access, enum arch_timer_reg reg, u64 val,
127 struct clock_event_device *clk)
128{
129 if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
130 struct arch_timer *timer = to_arch_timer(clk);
131 switch (reg) {
132 case ARCH_TIMER_REG_CTRL:
133 writel_relaxed((u32)val, timer->base + CNTP_CTL);
134 break;
135 case ARCH_TIMER_REG_CVAL:
136 /*
137 * Not guaranteed to be atomic, so the timer
138 * must be disabled at this point.
139 */
140 writeq_relaxed(val, timer->base + CNTP_CVAL_LO);
141 break;
142 default:
143 BUILD_BUG();
144 }
145 } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
146 struct arch_timer *timer = to_arch_timer(clk);
147 switch (reg) {
148 case ARCH_TIMER_REG_CTRL:
149 writel_relaxed((u32)val, timer->base + CNTV_CTL);
150 break;
151 case ARCH_TIMER_REG_CVAL:
152 /* Same restriction as above */
153 writeq_relaxed(val, timer->base + CNTV_CVAL_LO);
154 break;
155 default:
156 BUILD_BUG();
157 }
158 } else {
159 arch_timer_reg_write_cp15(access, reg, val);
160 }
161}
162
163static __always_inline
164u32 arch_timer_reg_read(int access, enum arch_timer_reg reg,
165 struct clock_event_device *clk)
166{
167 u32 val;
168
169 if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
170 struct arch_timer *timer = to_arch_timer(clk);
171 switch (reg) {
172 case ARCH_TIMER_REG_CTRL:
173 val = readl_relaxed(timer->base + CNTP_CTL);
174 break;
175 default:
176 BUILD_BUG();
177 }
178 } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
179 struct arch_timer *timer = to_arch_timer(clk);
180 switch (reg) {
181 case ARCH_TIMER_REG_CTRL:
182 val = readl_relaxed(timer->base + CNTV_CTL);
183 break;
184 default:
185 BUILD_BUG();
186 }
187 } else {
188 val = arch_timer_reg_read_cp15(access, reg);
189 }
190
191 return val;
192}
193
194static noinstr u64 raw_counter_get_cntpct_stable(void)
195{
196 return __arch_counter_get_cntpct_stable();
197}
198
199static notrace u64 arch_counter_get_cntpct_stable(void)
200{
201 u64 val;
202 preempt_disable_notrace();
203 val = __arch_counter_get_cntpct_stable();
204 preempt_enable_notrace();
205 return val;
206}
207
208static noinstr u64 arch_counter_get_cntpct(void)
209{
210 return __arch_counter_get_cntpct();
211}
212
213static noinstr u64 raw_counter_get_cntvct_stable(void)
214{
215 return __arch_counter_get_cntvct_stable();
216}
217
218static notrace u64 arch_counter_get_cntvct_stable(void)
219{
220 u64 val;
221 preempt_disable_notrace();
222 val = __arch_counter_get_cntvct_stable();
223 preempt_enable_notrace();
224 return val;
225}
226
227static noinstr u64 arch_counter_get_cntvct(void)
228{
229 return __arch_counter_get_cntvct();
230}
231
232/*
233 * Default to cp15 based access because arm64 uses this function for
234 * sched_clock() before DT is probed and the cp15 method is guaranteed
235 * to exist on arm64. arm doesn't use this before DT is probed so even
236 * if we don't have the cp15 accessors we won't have a problem.
237 */
238u64 (*arch_timer_read_counter)(void) __ro_after_init = arch_counter_get_cntvct;
239EXPORT_SYMBOL_GPL(arch_timer_read_counter);
240
241static u64 arch_counter_read(struct clocksource *cs)
242{
243 return arch_timer_read_counter();
244}
245
246static u64 arch_counter_read_cc(const struct cyclecounter *cc)
247{
248 return arch_timer_read_counter();
249}
250
251static struct clocksource clocksource_counter = {
252 .name = "arch_sys_counter",
253 .id = CSID_ARM_ARCH_COUNTER,
254 .rating = 400,
255 .read = arch_counter_read,
256 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
257};
258
259static struct cyclecounter cyclecounter __ro_after_init = {
260 .read = arch_counter_read_cc,
261};
262
263struct ate_acpi_oem_info {
264 char oem_id[ACPI_OEM_ID_SIZE + 1];
265 char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
266 u32 oem_revision;
267};
268
269#ifdef CONFIG_FSL_ERRATUM_A008585
270/*
271 * The number of retries is an arbitrary value well beyond the highest number
272 * of iterations the loop has been observed to take.
273 */
274#define __fsl_a008585_read_reg(reg) ({ \
275 u64 _old, _new; \
276 int _retries = 200; \
277 \
278 do { \
279 _old = read_sysreg(reg); \
280 _new = read_sysreg(reg); \
281 _retries--; \
282 } while (unlikely(_old != _new) && _retries); \
283 \
284 WARN_ON_ONCE(!_retries); \
285 _new; \
286})
287
288static u64 notrace fsl_a008585_read_cntpct_el0(void)
289{
290 return __fsl_a008585_read_reg(cntpct_el0);
291}
292
293static u64 notrace fsl_a008585_read_cntvct_el0(void)
294{
295 return __fsl_a008585_read_reg(cntvct_el0);
296}
297#endif
298
299#ifdef CONFIG_HISILICON_ERRATUM_161010101
300/*
301 * Verify whether the value of the second read is larger than the first by
302 * less than 32 is the only way to confirm the value is correct, so clear the
303 * lower 5 bits to check whether the difference is greater than 32 or not.
304 * Theoretically the erratum should not occur more than twice in succession
305 * when reading the system counter, but it is possible that some interrupts
306 * may lead to more than twice read errors, triggering the warning, so setting
307 * the number of retries far beyond the number of iterations the loop has been
308 * observed to take.
309 */
310#define __hisi_161010101_read_reg(reg) ({ \
311 u64 _old, _new; \
312 int _retries = 50; \
313 \
314 do { \
315 _old = read_sysreg(reg); \
316 _new = read_sysreg(reg); \
317 _retries--; \
318 } while (unlikely((_new - _old) >> 5) && _retries); \
319 \
320 WARN_ON_ONCE(!_retries); \
321 _new; \
322})
323
324static u64 notrace hisi_161010101_read_cntpct_el0(void)
325{
326 return __hisi_161010101_read_reg(cntpct_el0);
327}
328
329static u64 notrace hisi_161010101_read_cntvct_el0(void)
330{
331 return __hisi_161010101_read_reg(cntvct_el0);
332}
333
334static struct ate_acpi_oem_info hisi_161010101_oem_info[] = {
335 /*
336 * Note that trailing spaces are required to properly match
337 * the OEM table information.
338 */
339 {
340 .oem_id = "HISI ",
341 .oem_table_id = "HIP05 ",
342 .oem_revision = 0,
343 },
344 {
345 .oem_id = "HISI ",
346 .oem_table_id = "HIP06 ",
347 .oem_revision = 0,
348 },
349 {
350 .oem_id = "HISI ",
351 .oem_table_id = "HIP07 ",
352 .oem_revision = 0,
353 },
354 { /* Sentinel indicating the end of the OEM array */ },
355};
356#endif
357
358#ifdef CONFIG_ARM64_ERRATUM_858921
359static u64 notrace arm64_858921_read_cntpct_el0(void)
360{
361 u64 old, new;
362
363 old = read_sysreg(cntpct_el0);
364 new = read_sysreg(cntpct_el0);
365 return (((old ^ new) >> 32) & 1) ? old : new;
366}
367
368static u64 notrace arm64_858921_read_cntvct_el0(void)
369{
370 u64 old, new;
371
372 old = read_sysreg(cntvct_el0);
373 new = read_sysreg(cntvct_el0);
374 return (((old ^ new) >> 32) & 1) ? old : new;
375}
376#endif
377
378#ifdef CONFIG_SUN50I_ERRATUM_UNKNOWN1
379/*
380 * The low bits of the counter registers are indeterminate while bit 10 or
381 * greater is rolling over. Since the counter value can jump both backward
382 * (7ff -> 000 -> 800) and forward (7ff -> fff -> 800), ignore register values
383 * with all ones or all zeros in the low bits. Bound the loop by the maximum
384 * number of CPU cycles in 3 consecutive 24 MHz counter periods.
385 */
386#define __sun50i_a64_read_reg(reg) ({ \
387 u64 _val; \
388 int _retries = 150; \
389 \
390 do { \
391 _val = read_sysreg(reg); \
392 _retries--; \
393 } while (((_val + 1) & GENMASK(8, 0)) <= 1 && _retries); \
394 \
395 WARN_ON_ONCE(!_retries); \
396 _val; \
397})
398
399static u64 notrace sun50i_a64_read_cntpct_el0(void)
400{
401 return __sun50i_a64_read_reg(cntpct_el0);
402}
403
404static u64 notrace sun50i_a64_read_cntvct_el0(void)
405{
406 return __sun50i_a64_read_reg(cntvct_el0);
407}
408#endif
409
410#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
411DEFINE_PER_CPU(const struct arch_timer_erratum_workaround *, timer_unstable_counter_workaround);
412EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround);
413
414static atomic_t timer_unstable_counter_workaround_in_use = ATOMIC_INIT(0);
415
416/*
417 * Force the inlining of this function so that the register accesses
418 * can be themselves correctly inlined.
419 */
420static __always_inline
421void erratum_set_next_event_generic(const int access, unsigned long evt,
422 struct clock_event_device *clk)
423{
424 unsigned long ctrl;
425 u64 cval;
426
427 ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
428 ctrl |= ARCH_TIMER_CTRL_ENABLE;
429 ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
430
431 if (access == ARCH_TIMER_PHYS_ACCESS) {
432 cval = evt + arch_counter_get_cntpct_stable();
433 write_sysreg(cval, cntp_cval_el0);
434 } else {
435 cval = evt + arch_counter_get_cntvct_stable();
436 write_sysreg(cval, cntv_cval_el0);
437 }
438
439 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
440}
441
442static __maybe_unused int erratum_set_next_event_virt(unsigned long evt,
443 struct clock_event_device *clk)
444{
445 erratum_set_next_event_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk);
446 return 0;
447}
448
449static __maybe_unused int erratum_set_next_event_phys(unsigned long evt,
450 struct clock_event_device *clk)
451{
452 erratum_set_next_event_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk);
453 return 0;
454}
455
456static const struct arch_timer_erratum_workaround ool_workarounds[] = {
457#ifdef CONFIG_FSL_ERRATUM_A008585
458 {
459 .match_type = ate_match_dt,
460 .id = "fsl,erratum-a008585",
461 .desc = "Freescale erratum a005858",
462 .read_cntpct_el0 = fsl_a008585_read_cntpct_el0,
463 .read_cntvct_el0 = fsl_a008585_read_cntvct_el0,
464 .set_next_event_phys = erratum_set_next_event_phys,
465 .set_next_event_virt = erratum_set_next_event_virt,
466 },
467#endif
468#ifdef CONFIG_HISILICON_ERRATUM_161010101
469 {
470 .match_type = ate_match_dt,
471 .id = "hisilicon,erratum-161010101",
472 .desc = "HiSilicon erratum 161010101",
473 .read_cntpct_el0 = hisi_161010101_read_cntpct_el0,
474 .read_cntvct_el0 = hisi_161010101_read_cntvct_el0,
475 .set_next_event_phys = erratum_set_next_event_phys,
476 .set_next_event_virt = erratum_set_next_event_virt,
477 },
478 {
479 .match_type = ate_match_acpi_oem_info,
480 .id = hisi_161010101_oem_info,
481 .desc = "HiSilicon erratum 161010101",
482 .read_cntpct_el0 = hisi_161010101_read_cntpct_el0,
483 .read_cntvct_el0 = hisi_161010101_read_cntvct_el0,
484 .set_next_event_phys = erratum_set_next_event_phys,
485 .set_next_event_virt = erratum_set_next_event_virt,
486 },
487#endif
488#ifdef CONFIG_ARM64_ERRATUM_858921
489 {
490 .match_type = ate_match_local_cap_id,
491 .id = (void *)ARM64_WORKAROUND_858921,
492 .desc = "ARM erratum 858921",
493 .read_cntpct_el0 = arm64_858921_read_cntpct_el0,
494 .read_cntvct_el0 = arm64_858921_read_cntvct_el0,
495 .set_next_event_phys = erratum_set_next_event_phys,
496 .set_next_event_virt = erratum_set_next_event_virt,
497 },
498#endif
499#ifdef CONFIG_SUN50I_ERRATUM_UNKNOWN1
500 {
501 .match_type = ate_match_dt,
502 .id = "allwinner,erratum-unknown1",
503 .desc = "Allwinner erratum UNKNOWN1",
504 .read_cntpct_el0 = sun50i_a64_read_cntpct_el0,
505 .read_cntvct_el0 = sun50i_a64_read_cntvct_el0,
506 .set_next_event_phys = erratum_set_next_event_phys,
507 .set_next_event_virt = erratum_set_next_event_virt,
508 },
509#endif
510#ifdef CONFIG_ARM64_ERRATUM_1418040
511 {
512 .match_type = ate_match_local_cap_id,
513 .id = (void *)ARM64_WORKAROUND_1418040,
514 .desc = "ARM erratum 1418040",
515 .disable_compat_vdso = true,
516 },
517#endif
518};
519
520typedef bool (*ate_match_fn_t)(const struct arch_timer_erratum_workaround *,
521 const void *);
522
523static
524bool arch_timer_check_dt_erratum(const struct arch_timer_erratum_workaround *wa,
525 const void *arg)
526{
527 const struct device_node *np = arg;
528
529 return of_property_read_bool(np, wa->id);
530}
531
532static
533bool arch_timer_check_local_cap_erratum(const struct arch_timer_erratum_workaround *wa,
534 const void *arg)
535{
536 return this_cpu_has_cap((uintptr_t)wa->id);
537}
538
539
540static
541bool arch_timer_check_acpi_oem_erratum(const struct arch_timer_erratum_workaround *wa,
542 const void *arg)
543{
544 static const struct ate_acpi_oem_info empty_oem_info = {};
545 const struct ate_acpi_oem_info *info = wa->id;
546 const struct acpi_table_header *table = arg;
547
548 /* Iterate over the ACPI OEM info array, looking for a match */
549 while (memcmp(info, &empty_oem_info, sizeof(*info))) {
550 if (!memcmp(info->oem_id, table->oem_id, ACPI_OEM_ID_SIZE) &&
551 !memcmp(info->oem_table_id, table->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
552 info->oem_revision == table->oem_revision)
553 return true;
554
555 info++;
556 }
557
558 return false;
559}
560
561static const struct arch_timer_erratum_workaround *
562arch_timer_iterate_errata(enum arch_timer_erratum_match_type type,
563 ate_match_fn_t match_fn,
564 void *arg)
565{
566 int i;
567
568 for (i = 0; i < ARRAY_SIZE(ool_workarounds); i++) {
569 if (ool_workarounds[i].match_type != type)
570 continue;
571
572 if (match_fn(&ool_workarounds[i], arg))
573 return &ool_workarounds[i];
574 }
575
576 return NULL;
577}
578
579static
580void arch_timer_enable_workaround(const struct arch_timer_erratum_workaround *wa,
581 bool local)
582{
583 int i;
584
585 if (local) {
586 __this_cpu_write(timer_unstable_counter_workaround, wa);
587 } else {
588 for_each_possible_cpu(i)
589 per_cpu(timer_unstable_counter_workaround, i) = wa;
590 }
591
592 if (wa->read_cntvct_el0 || wa->read_cntpct_el0)
593 atomic_set(&timer_unstable_counter_workaround_in_use, 1);
594
595 /*
596 * Don't use the vdso fastpath if errata require using the
597 * out-of-line counter accessor. We may change our mind pretty
598 * late in the game (with a per-CPU erratum, for example), so
599 * change both the default value and the vdso itself.
600 */
601 if (wa->read_cntvct_el0) {
602 clocksource_counter.vdso_clock_mode = VDSO_CLOCKMODE_NONE;
603 vdso_default = VDSO_CLOCKMODE_NONE;
604 } else if (wa->disable_compat_vdso && vdso_default != VDSO_CLOCKMODE_NONE) {
605 vdso_default = VDSO_CLOCKMODE_ARCHTIMER_NOCOMPAT;
606 clocksource_counter.vdso_clock_mode = vdso_default;
607 }
608}
609
610static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type type,
611 void *arg)
612{
613 const struct arch_timer_erratum_workaround *wa, *__wa;
614 ate_match_fn_t match_fn = NULL;
615 bool local = false;
616
617 switch (type) {
618 case ate_match_dt:
619 match_fn = arch_timer_check_dt_erratum;
620 break;
621 case ate_match_local_cap_id:
622 match_fn = arch_timer_check_local_cap_erratum;
623 local = true;
624 break;
625 case ate_match_acpi_oem_info:
626 match_fn = arch_timer_check_acpi_oem_erratum;
627 break;
628 default:
629 WARN_ON(1);
630 return;
631 }
632
633 wa = arch_timer_iterate_errata(type, match_fn, arg);
634 if (!wa)
635 return;
636
637 __wa = __this_cpu_read(timer_unstable_counter_workaround);
638 if (__wa && wa != __wa)
639 pr_warn("Can't enable workaround for %s (clashes with %s\n)",
640 wa->desc, __wa->desc);
641
642 if (__wa)
643 return;
644
645 arch_timer_enable_workaround(wa, local);
646 pr_info("Enabling %s workaround for %s\n",
647 local ? "local" : "global", wa->desc);
648}
649
650static bool arch_timer_this_cpu_has_cntvct_wa(void)
651{
652 return has_erratum_handler(read_cntvct_el0);
653}
654
655static bool arch_timer_counter_has_wa(void)
656{
657 return atomic_read(&timer_unstable_counter_workaround_in_use);
658}
659#else
660#define arch_timer_check_ool_workaround(t,a) do { } while(0)
661#define arch_timer_this_cpu_has_cntvct_wa() ({false;})
662#define arch_timer_counter_has_wa() ({false;})
663#endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */
664
665static __always_inline irqreturn_t timer_handler(const int access,
666 struct clock_event_device *evt)
667{
668 unsigned long ctrl;
669
670 ctrl = arch_timer_reg_read(access, reg: ARCH_TIMER_REG_CTRL, clk: evt);
671 if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
672 ctrl |= ARCH_TIMER_CTRL_IT_MASK;
673 arch_timer_reg_write(access, reg: ARCH_TIMER_REG_CTRL, val: ctrl, clk: evt);
674 evt->event_handler(evt);
675 return IRQ_HANDLED;
676 }
677
678 return IRQ_NONE;
679}
680
681static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id)
682{
683 struct clock_event_device *evt = dev_id;
684
685 return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
686}
687
688static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id)
689{
690 struct clock_event_device *evt = dev_id;
691
692 return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
693}
694
695static irqreturn_t arch_timer_handler_phys_mem(int irq, void *dev_id)
696{
697 struct clock_event_device *evt = dev_id;
698
699 return timer_handler(ARCH_TIMER_MEM_PHYS_ACCESS, evt);
700}
701
702static irqreturn_t arch_timer_handler_virt_mem(int irq, void *dev_id)
703{
704 struct clock_event_device *evt = dev_id;
705
706 return timer_handler(ARCH_TIMER_MEM_VIRT_ACCESS, evt);
707}
708
709static __always_inline int arch_timer_shutdown(const int access,
710 struct clock_event_device *clk)
711{
712 unsigned long ctrl;
713
714 ctrl = arch_timer_reg_read(access, reg: ARCH_TIMER_REG_CTRL, clk);
715 ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
716 arch_timer_reg_write(access, reg: ARCH_TIMER_REG_CTRL, val: ctrl, clk);
717
718 return 0;
719}
720
721static int arch_timer_shutdown_virt(struct clock_event_device *clk)
722{
723 return arch_timer_shutdown(ARCH_TIMER_VIRT_ACCESS, clk);
724}
725
726static int arch_timer_shutdown_phys(struct clock_event_device *clk)
727{
728 return arch_timer_shutdown(ARCH_TIMER_PHYS_ACCESS, clk);
729}
730
731static int arch_timer_shutdown_virt_mem(struct clock_event_device *clk)
732{
733 return arch_timer_shutdown(ARCH_TIMER_MEM_VIRT_ACCESS, clk);
734}
735
736static int arch_timer_shutdown_phys_mem(struct clock_event_device *clk)
737{
738 return arch_timer_shutdown(ARCH_TIMER_MEM_PHYS_ACCESS, clk);
739}
740
741static __always_inline void set_next_event(const int access, unsigned long evt,
742 struct clock_event_device *clk)
743{
744 unsigned long ctrl;
745 u64 cnt;
746
747 ctrl = arch_timer_reg_read(access, reg: ARCH_TIMER_REG_CTRL, clk);
748 ctrl |= ARCH_TIMER_CTRL_ENABLE;
749 ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
750
751 if (access == ARCH_TIMER_PHYS_ACCESS)
752 cnt = __arch_counter_get_cntpct();
753 else
754 cnt = __arch_counter_get_cntvct();
755
756 arch_timer_reg_write(access, reg: ARCH_TIMER_REG_CVAL, val: evt + cnt, clk);
757 arch_timer_reg_write(access, reg: ARCH_TIMER_REG_CTRL, val: ctrl, clk);
758}
759
760static int arch_timer_set_next_event_virt(unsigned long evt,
761 struct clock_event_device *clk)
762{
763 set_next_event(ARCH_TIMER_VIRT_ACCESS, evt, clk);
764 return 0;
765}
766
767static int arch_timer_set_next_event_phys(unsigned long evt,
768 struct clock_event_device *clk)
769{
770 set_next_event(ARCH_TIMER_PHYS_ACCESS, evt, clk);
771 return 0;
772}
773
774static noinstr u64 arch_counter_get_cnt_mem(struct arch_timer *t, int offset_lo)
775{
776 u32 cnt_lo, cnt_hi, tmp_hi;
777
778 do {
779 cnt_hi = __le32_to_cpu((__le32 __force)__raw_readl(t->base + offset_lo + 4));
780 cnt_lo = __le32_to_cpu((__le32 __force)__raw_readl(t->base + offset_lo));
781 tmp_hi = __le32_to_cpu((__le32 __force)__raw_readl(t->base + offset_lo + 4));
782 } while (cnt_hi != tmp_hi);
783
784 return ((u64) cnt_hi << 32) | cnt_lo;
785}
786
787static __always_inline void set_next_event_mem(const int access, unsigned long evt,
788 struct clock_event_device *clk)
789{
790 struct arch_timer *timer = to_arch_timer(clk);
791 unsigned long ctrl;
792 u64 cnt;
793
794 ctrl = arch_timer_reg_read(access, reg: ARCH_TIMER_REG_CTRL, clk);
795
796 /* Timer must be disabled before programming CVAL */
797 if (ctrl & ARCH_TIMER_CTRL_ENABLE) {
798 ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
799 arch_timer_reg_write(access, reg: ARCH_TIMER_REG_CTRL, val: ctrl, clk);
800 }
801
802 ctrl |= ARCH_TIMER_CTRL_ENABLE;
803 ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
804
805 if (access == ARCH_TIMER_MEM_VIRT_ACCESS)
806 cnt = arch_counter_get_cnt_mem(t: timer, CNTVCT_LO);
807 else
808 cnt = arch_counter_get_cnt_mem(t: timer, CNTPCT_LO);
809
810 arch_timer_reg_write(access, reg: ARCH_TIMER_REG_CVAL, val: evt + cnt, clk);
811 arch_timer_reg_write(access, reg: ARCH_TIMER_REG_CTRL, val: ctrl, clk);
812}
813
814static int arch_timer_set_next_event_virt_mem(unsigned long evt,
815 struct clock_event_device *clk)
816{
817 set_next_event_mem(ARCH_TIMER_MEM_VIRT_ACCESS, evt, clk);
818 return 0;
819}
820
821static int arch_timer_set_next_event_phys_mem(unsigned long evt,
822 struct clock_event_device *clk)
823{
824 set_next_event_mem(ARCH_TIMER_MEM_PHYS_ACCESS, evt, clk);
825 return 0;
826}
827
828static u64 __arch_timer_check_delta(void)
829{
830#ifdef CONFIG_ARM64
831 const struct midr_range broken_cval_midrs[] = {
832 /*
833 * XGene-1 implements CVAL in terms of TVAL, meaning
834 * that the maximum timer range is 32bit. Shame on them.
835 *
836 * Note that TVAL is signed, thus has only 31 of its
837 * 32 bits to express magnitude.
838 */
839 MIDR_REV_RANGE(MIDR_CPU_MODEL(ARM_CPU_IMP_APM,
840 APM_CPU_PART_XGENE),
841 APM_CPU_VAR_POTENZA, 0x0, 0xf),
842 {},
843 };
844
845 if (is_midr_in_range_list(read_cpuid_id(), broken_cval_midrs)) {
846 pr_warn_once("Broken CNTx_CVAL_EL1, using 31 bit TVAL instead.\n");
847 return CLOCKSOURCE_MASK(31);
848 }
849#endif
850 return CLOCKSOURCE_MASK(arch_counter_get_width());
851}
852
853static void __arch_timer_setup(unsigned type,
854 struct clock_event_device *clk)
855{
856 u64 max_delta;
857
858 clk->features = CLOCK_EVT_FEAT_ONESHOT;
859
860 if (type == ARCH_TIMER_TYPE_CP15) {
861 typeof(clk->set_next_event) sne;
862
863 arch_timer_check_ool_workaround(ate_match_local_cap_id, NULL);
864
865 if (arch_timer_c3stop)
866 clk->features |= CLOCK_EVT_FEAT_C3STOP;
867 clk->name = "arch_sys_timer";
868 clk->rating = 450;
869 clk->cpumask = cpumask_of(smp_processor_id());
870 clk->irq = arch_timer_ppi[arch_timer_uses_ppi];
871 switch (arch_timer_uses_ppi) {
872 case ARCH_TIMER_VIRT_PPI:
873 clk->set_state_shutdown = arch_timer_shutdown_virt;
874 clk->set_state_oneshot_stopped = arch_timer_shutdown_virt;
875 sne = erratum_handler(set_next_event_virt);
876 break;
877 case ARCH_TIMER_PHYS_SECURE_PPI:
878 case ARCH_TIMER_PHYS_NONSECURE_PPI:
879 case ARCH_TIMER_HYP_PPI:
880 clk->set_state_shutdown = arch_timer_shutdown_phys;
881 clk->set_state_oneshot_stopped = arch_timer_shutdown_phys;
882 sne = erratum_handler(set_next_event_phys);
883 break;
884 default:
885 BUG();
886 }
887
888 clk->set_next_event = sne;
889 max_delta = __arch_timer_check_delta();
890 } else {
891 clk->features |= CLOCK_EVT_FEAT_DYNIRQ;
892 clk->name = "arch_mem_timer";
893 clk->rating = 400;
894 clk->cpumask = cpu_possible_mask;
895 if (arch_timer_mem_use_virtual) {
896 clk->set_state_shutdown = arch_timer_shutdown_virt_mem;
897 clk->set_state_oneshot_stopped = arch_timer_shutdown_virt_mem;
898 clk->set_next_event =
899 arch_timer_set_next_event_virt_mem;
900 } else {
901 clk->set_state_shutdown = arch_timer_shutdown_phys_mem;
902 clk->set_state_oneshot_stopped = arch_timer_shutdown_phys_mem;
903 clk->set_next_event =
904 arch_timer_set_next_event_phys_mem;
905 }
906
907 max_delta = CLOCKSOURCE_MASK(56);
908 }
909
910 clk->set_state_shutdown(clk);
911
912 clockevents_config_and_register(dev: clk, freq: arch_timer_rate, min_delta: 0xf, max_delta);
913}
914
915static void arch_timer_evtstrm_enable(unsigned int divider)
916{
917 u32 cntkctl = arch_timer_get_cntkctl();
918
919#ifdef CONFIG_ARM64
920 /* ECV is likely to require a large divider. Use the EVNTIS flag. */
921 if (cpus_have_final_cap(ARM64_HAS_ECV) && divider > 15) {
922 cntkctl |= ARCH_TIMER_EVT_INTERVAL_SCALE;
923 divider -= 8;
924 }
925#endif
926
927 divider = min(divider, 15U);
928 cntkctl &= ~ARCH_TIMER_EVT_TRIGGER_MASK;
929 /* Set the divider and enable virtual event stream */
930 cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT)
931 | ARCH_TIMER_VIRT_EVT_EN;
932 arch_timer_set_cntkctl(cntkctl);
933 arch_timer_set_evtstrm_feature();
934 cpumask_set_cpu(smp_processor_id(), dstp: &evtstrm_available);
935}
936
937static void arch_timer_configure_evtstream(void)
938{
939 int evt_stream_div, lsb;
940
941 /*
942 * As the event stream can at most be generated at half the frequency
943 * of the counter, use half the frequency when computing the divider.
944 */
945 evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ / 2;
946
947 /*
948 * Find the closest power of two to the divisor. If the adjacent bit
949 * of lsb (last set bit, starts from 0) is set, then we use (lsb + 1).
950 */
951 lsb = fls(x: evt_stream_div) - 1;
952 if (lsb > 0 && (evt_stream_div & BIT(lsb - 1)))
953 lsb++;
954
955 /* enable event stream */
956 arch_timer_evtstrm_enable(max(0, lsb));
957}
958
959static int arch_timer_evtstrm_starting_cpu(unsigned int cpu)
960{
961 arch_timer_configure_evtstream();
962 return 0;
963}
964
965static int arch_timer_evtstrm_dying_cpu(unsigned int cpu)
966{
967 cpumask_clear_cpu(smp_processor_id(), dstp: &evtstrm_available);
968 return 0;
969}
970
971static int __init arch_timer_evtstrm_register(void)
972{
973 if (!arch_timer_evt || !evtstrm_enable)
974 return 0;
975
976 return cpuhp_setup_state(state: CPUHP_AP_ARM_ARCH_TIMER_EVTSTRM_STARTING,
977 name: "clockevents/arm/arch_timer_evtstrm:starting",
978 startup: arch_timer_evtstrm_starting_cpu,
979 teardown: arch_timer_evtstrm_dying_cpu);
980}
981core_initcall(arch_timer_evtstrm_register);
982
983static void arch_counter_set_user_access(void)
984{
985 u32 cntkctl = arch_timer_get_cntkctl();
986
987 /* Disable user access to the timers and both counters */
988 /* Also disable virtual event stream */
989 cntkctl &= ~(ARCH_TIMER_USR_PT_ACCESS_EN
990 | ARCH_TIMER_USR_VT_ACCESS_EN
991 | ARCH_TIMER_USR_VCT_ACCESS_EN
992 | ARCH_TIMER_VIRT_EVT_EN
993 | ARCH_TIMER_USR_PCT_ACCESS_EN);
994
995 /*
996 * Enable user access to the virtual counter if it doesn't
997 * need to be workaround. The vdso may have been already
998 * disabled though.
999 */
1000 if (arch_timer_this_cpu_has_cntvct_wa())
1001 pr_info("CPU%d: Trapping CNTVCT access\n", smp_processor_id());
1002 else
1003 cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN;
1004
1005 arch_timer_set_cntkctl(cntkctl);
1006}
1007
1008static bool arch_timer_has_nonsecure_ppi(void)
1009{
1010 return (arch_timer_uses_ppi == ARCH_TIMER_PHYS_SECURE_PPI &&
1011 arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
1012}
1013
1014static u32 check_ppi_trigger(int irq)
1015{
1016 u32 flags = irq_get_trigger_type(irq);
1017
1018 if (flags != IRQF_TRIGGER_HIGH && flags != IRQF_TRIGGER_LOW) {
1019 pr_warn("WARNING: Invalid trigger for IRQ%d, assuming level low\n", irq);
1020 pr_warn("WARNING: Please fix your firmware\n");
1021 flags = IRQF_TRIGGER_LOW;
1022 }
1023
1024 return flags;
1025}
1026
1027static int arch_timer_starting_cpu(unsigned int cpu)
1028{
1029 struct clock_event_device *clk = this_cpu_ptr(arch_timer_evt);
1030 u32 flags;
1031
1032 __arch_timer_setup(ARCH_TIMER_TYPE_CP15, clk);
1033
1034 flags = check_ppi_trigger(irq: arch_timer_ppi[arch_timer_uses_ppi]);
1035 enable_percpu_irq(irq: arch_timer_ppi[arch_timer_uses_ppi], type: flags);
1036
1037 if (arch_timer_has_nonsecure_ppi()) {
1038 flags = check_ppi_trigger(irq: arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
1039 enable_percpu_irq(irq: arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI],
1040 type: flags);
1041 }
1042
1043 arch_counter_set_user_access();
1044
1045 return 0;
1046}
1047
1048static int validate_timer_rate(void)
1049{
1050 if (!arch_timer_rate)
1051 return -EINVAL;
1052
1053 /* Arch timer frequency < 1MHz can cause trouble */
1054 WARN_ON(arch_timer_rate < 1000000);
1055
1056 return 0;
1057}
1058
1059/*
1060 * For historical reasons, when probing with DT we use whichever (non-zero)
1061 * rate was probed first, and don't verify that others match. If the first node
1062 * probed has a clock-frequency property, this overrides the HW register.
1063 */
1064static void __init arch_timer_of_configure_rate(u32 rate, struct device_node *np)
1065{
1066 /* Who has more than one independent system counter? */
1067 if (arch_timer_rate)
1068 return;
1069
1070 if (of_property_read_u32(np, propname: "clock-frequency", out_value: &arch_timer_rate))
1071 arch_timer_rate = rate;
1072
1073 /* Check the timer frequency. */
1074 if (validate_timer_rate())
1075 pr_warn("frequency not available\n");
1076}
1077
1078static void __init arch_timer_banner(unsigned type)
1079{
1080 pr_info("%s%s%s timer(s) running at %lu.%02luMHz (%s%s%s).\n",
1081 type & ARCH_TIMER_TYPE_CP15 ? "cp15" : "",
1082 type == (ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM) ?
1083 " and " : "",
1084 type & ARCH_TIMER_TYPE_MEM ? "mmio" : "",
1085 (unsigned long)arch_timer_rate / 1000000,
1086 (unsigned long)(arch_timer_rate / 10000) % 100,
1087 type & ARCH_TIMER_TYPE_CP15 ?
1088 (arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI) ? "virt" : "phys" :
1089 "",
1090 type == (ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM) ? "/" : "",
1091 type & ARCH_TIMER_TYPE_MEM ?
1092 arch_timer_mem_use_virtual ? "virt" : "phys" :
1093 "");
1094}
1095
1096u32 arch_timer_get_rate(void)
1097{
1098 return arch_timer_rate;
1099}
1100
1101bool arch_timer_evtstrm_available(void)
1102{
1103 /*
1104 * We might get called from a preemptible context. This is fine
1105 * because availability of the event stream should be always the same
1106 * for a preemptible context and context where we might resume a task.
1107 */
1108 return cpumask_test_cpu(raw_smp_processor_id(), cpumask: &evtstrm_available);
1109}
1110
1111static noinstr u64 arch_counter_get_cntvct_mem(void)
1112{
1113 return arch_counter_get_cnt_mem(t: arch_timer_mem, CNTVCT_LO);
1114}
1115
1116static struct arch_timer_kvm_info arch_timer_kvm_info;
1117
1118struct arch_timer_kvm_info *arch_timer_get_kvm_info(void)
1119{
1120 return &arch_timer_kvm_info;
1121}
1122
1123static void __init arch_counter_register(unsigned type)
1124{
1125 u64 (*scr)(void);
1126 u64 start_count;
1127 int width;
1128
1129 /* Register the CP15 based counter if we have one */
1130 if (type & ARCH_TIMER_TYPE_CP15) {
1131 u64 (*rd)(void);
1132
1133 if ((IS_ENABLED(CONFIG_ARM64) && !is_hyp_mode_available()) ||
1134 arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI) {
1135 if (arch_timer_counter_has_wa()) {
1136 rd = arch_counter_get_cntvct_stable;
1137 scr = raw_counter_get_cntvct_stable;
1138 } else {
1139 rd = arch_counter_get_cntvct;
1140 scr = arch_counter_get_cntvct;
1141 }
1142 } else {
1143 if (arch_timer_counter_has_wa()) {
1144 rd = arch_counter_get_cntpct_stable;
1145 scr = raw_counter_get_cntpct_stable;
1146 } else {
1147 rd = arch_counter_get_cntpct;
1148 scr = arch_counter_get_cntpct;
1149 }
1150 }
1151
1152 arch_timer_read_counter = rd;
1153 clocksource_counter.vdso_clock_mode = vdso_default;
1154 } else {
1155 arch_timer_read_counter = arch_counter_get_cntvct_mem;
1156 scr = arch_counter_get_cntvct_mem;
1157 }
1158
1159 width = arch_counter_get_width();
1160 clocksource_counter.mask = CLOCKSOURCE_MASK(width);
1161 cyclecounter.mask = CLOCKSOURCE_MASK(width);
1162
1163 if (!arch_counter_suspend_stop)
1164 clocksource_counter.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP;
1165 start_count = arch_timer_read_counter();
1166 clocksource_register_hz(cs: &clocksource_counter, hz: arch_timer_rate);
1167 cyclecounter.mult = clocksource_counter.mult;
1168 cyclecounter.shift = clocksource_counter.shift;
1169 timecounter_init(tc: &arch_timer_kvm_info.timecounter,
1170 cc: &cyclecounter, start_tstamp: start_count);
1171
1172 sched_clock_register(read: scr, bits: width, rate: arch_timer_rate);
1173}
1174
1175static void arch_timer_stop(struct clock_event_device *clk)
1176{
1177 pr_debug("disable IRQ%d cpu #%d\n", clk->irq, smp_processor_id());
1178
1179 disable_percpu_irq(irq: arch_timer_ppi[arch_timer_uses_ppi]);
1180 if (arch_timer_has_nonsecure_ppi())
1181 disable_percpu_irq(irq: arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
1182
1183 clk->set_state_shutdown(clk);
1184}
1185
1186static int arch_timer_dying_cpu(unsigned int cpu)
1187{
1188 struct clock_event_device *clk = this_cpu_ptr(arch_timer_evt);
1189
1190 arch_timer_stop(clk);
1191 return 0;
1192}
1193
1194#ifdef CONFIG_CPU_PM
1195static DEFINE_PER_CPU(unsigned long, saved_cntkctl);
1196static int arch_timer_cpu_pm_notify(struct notifier_block *self,
1197 unsigned long action, void *hcpu)
1198{
1199 if (action == CPU_PM_ENTER) {
1200 __this_cpu_write(saved_cntkctl, arch_timer_get_cntkctl());
1201
1202 cpumask_clear_cpu(smp_processor_id(), &evtstrm_available);
1203 } else if (action == CPU_PM_ENTER_FAILED || action == CPU_PM_EXIT) {
1204 arch_timer_set_cntkctl(__this_cpu_read(saved_cntkctl));
1205
1206 if (arch_timer_have_evtstrm_feature())
1207 cpumask_set_cpu(smp_processor_id(), &evtstrm_available);
1208 }
1209 return NOTIFY_OK;
1210}
1211
1212static struct notifier_block arch_timer_cpu_pm_notifier = {
1213 .notifier_call = arch_timer_cpu_pm_notify,
1214};
1215
1216static int __init arch_timer_cpu_pm_init(void)
1217{
1218 return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier);
1219}
1220
1221static void __init arch_timer_cpu_pm_deinit(void)
1222{
1223 WARN_ON(cpu_pm_unregister_notifier(&arch_timer_cpu_pm_notifier));
1224}
1225
1226#else
1227static int __init arch_timer_cpu_pm_init(void)
1228{
1229 return 0;
1230}
1231
1232static void __init arch_timer_cpu_pm_deinit(void)
1233{
1234}
1235#endif
1236
1237static int __init arch_timer_register(void)
1238{
1239 int err;
1240 int ppi;
1241
1242 arch_timer_evt = alloc_percpu(struct clock_event_device);
1243 if (!arch_timer_evt) {
1244 err = -ENOMEM;
1245 goto out;
1246 }
1247
1248 ppi = arch_timer_ppi[arch_timer_uses_ppi];
1249 switch (arch_timer_uses_ppi) {
1250 case ARCH_TIMER_VIRT_PPI:
1251 err = request_percpu_irq(irq: ppi, handler: arch_timer_handler_virt,
1252 devname: "arch_timer", percpu_dev_id: arch_timer_evt);
1253 break;
1254 case ARCH_TIMER_PHYS_SECURE_PPI:
1255 case ARCH_TIMER_PHYS_NONSECURE_PPI:
1256 err = request_percpu_irq(irq: ppi, handler: arch_timer_handler_phys,
1257 devname: "arch_timer", percpu_dev_id: arch_timer_evt);
1258 if (!err && arch_timer_has_nonsecure_ppi()) {
1259 ppi = arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI];
1260 err = request_percpu_irq(irq: ppi, handler: arch_timer_handler_phys,
1261 devname: "arch_timer", percpu_dev_id: arch_timer_evt);
1262 if (err)
1263 free_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_SECURE_PPI],
1264 arch_timer_evt);
1265 }
1266 break;
1267 case ARCH_TIMER_HYP_PPI:
1268 err = request_percpu_irq(irq: ppi, handler: arch_timer_handler_phys,
1269 devname: "arch_timer", percpu_dev_id: arch_timer_evt);
1270 break;
1271 default:
1272 BUG();
1273 }
1274
1275 if (err) {
1276 pr_err("can't register interrupt %d (%d)\n", ppi, err);
1277 goto out_free;
1278 }
1279
1280 err = arch_timer_cpu_pm_init();
1281 if (err)
1282 goto out_unreg_notify;
1283
1284 /* Register and immediately configure the timer on the boot CPU */
1285 err = cpuhp_setup_state(state: CPUHP_AP_ARM_ARCH_TIMER_STARTING,
1286 name: "clockevents/arm/arch_timer:starting",
1287 startup: arch_timer_starting_cpu, teardown: arch_timer_dying_cpu);
1288 if (err)
1289 goto out_unreg_cpupm;
1290 return 0;
1291
1292out_unreg_cpupm:
1293 arch_timer_cpu_pm_deinit();
1294
1295out_unreg_notify:
1296 free_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi], arch_timer_evt);
1297 if (arch_timer_has_nonsecure_ppi())
1298 free_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI],
1299 arch_timer_evt);
1300
1301out_free:
1302 free_percpu(pdata: arch_timer_evt);
1303 arch_timer_evt = NULL;
1304out:
1305 return err;
1306}
1307
1308static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
1309{
1310 int ret;
1311 irq_handler_t func;
1312
1313 arch_timer_mem = kzalloc(size: sizeof(*arch_timer_mem), GFP_KERNEL);
1314 if (!arch_timer_mem)
1315 return -ENOMEM;
1316
1317 arch_timer_mem->base = base;
1318 arch_timer_mem->evt.irq = irq;
1319 __arch_timer_setup(ARCH_TIMER_TYPE_MEM, clk: &arch_timer_mem->evt);
1320
1321 if (arch_timer_mem_use_virtual)
1322 func = arch_timer_handler_virt_mem;
1323 else
1324 func = arch_timer_handler_phys_mem;
1325
1326 ret = request_irq(irq, handler: func, IRQF_TIMER, name: "arch_mem_timer", dev: &arch_timer_mem->evt);
1327 if (ret) {
1328 pr_err("Failed to request mem timer irq\n");
1329 kfree(objp: arch_timer_mem);
1330 arch_timer_mem = NULL;
1331 }
1332
1333 return ret;
1334}
1335
1336static const struct of_device_id arch_timer_of_match[] __initconst = {
1337 { .compatible = "arm,armv7-timer", },
1338 { .compatible = "arm,armv8-timer", },
1339 {},
1340};
1341
1342static const struct of_device_id arch_timer_mem_of_match[] __initconst = {
1343 { .compatible = "arm,armv7-timer-mem", },
1344 {},
1345};
1346
1347static bool __init arch_timer_needs_of_probing(void)
1348{
1349 struct device_node *dn;
1350 bool needs_probing = false;
1351 unsigned int mask = ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM;
1352
1353 /* We have two timers, and both device-tree nodes are probed. */
1354 if ((arch_timers_present & mask) == mask)
1355 return false;
1356
1357 /*
1358 * Only one type of timer is probed,
1359 * check if we have another type of timer node in device-tree.
1360 */
1361 if (arch_timers_present & ARCH_TIMER_TYPE_CP15)
1362 dn = of_find_matching_node(NULL, matches: arch_timer_mem_of_match);
1363 else
1364 dn = of_find_matching_node(NULL, matches: arch_timer_of_match);
1365
1366 if (dn && of_device_is_available(device: dn))
1367 needs_probing = true;
1368
1369 of_node_put(node: dn);
1370
1371 return needs_probing;
1372}
1373
1374static int __init arch_timer_common_init(void)
1375{
1376 arch_timer_banner(type: arch_timers_present);
1377 arch_counter_register(type: arch_timers_present);
1378 return arch_timer_arch_init();
1379}
1380
1381/**
1382 * arch_timer_select_ppi() - Select suitable PPI for the current system.
1383 *
1384 * If HYP mode is available, we know that the physical timer
1385 * has been configured to be accessible from PL1. Use it, so
1386 * that a guest can use the virtual timer instead.
1387 *
1388 * On ARMv8.1 with VH extensions, the kernel runs in HYP. VHE
1389 * accesses to CNTP_*_EL1 registers are silently redirected to
1390 * their CNTHP_*_EL2 counterparts, and use a different PPI
1391 * number.
1392 *
1393 * If no interrupt provided for virtual timer, we'll have to
1394 * stick to the physical timer. It'd better be accessible...
1395 * For arm64 we never use the secure interrupt.
1396 *
1397 * Return: a suitable PPI type for the current system.
1398 */
1399static enum arch_timer_ppi_nr __init arch_timer_select_ppi(void)
1400{
1401 if (is_kernel_in_hyp_mode())
1402 return ARCH_TIMER_HYP_PPI;
1403
1404 if (!is_hyp_mode_available() && arch_timer_ppi[ARCH_TIMER_VIRT_PPI])
1405 return ARCH_TIMER_VIRT_PPI;
1406
1407 if (IS_ENABLED(CONFIG_ARM64))
1408 return ARCH_TIMER_PHYS_NONSECURE_PPI;
1409
1410 return ARCH_TIMER_PHYS_SECURE_PPI;
1411}
1412
1413static void __init arch_timer_populate_kvm_info(void)
1414{
1415 arch_timer_kvm_info.virtual_irq = arch_timer_ppi[ARCH_TIMER_VIRT_PPI];
1416 if (is_kernel_in_hyp_mode())
1417 arch_timer_kvm_info.physical_irq = arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI];
1418}
1419
1420static int __init arch_timer_of_init(struct device_node *np)
1421{
1422 int i, irq, ret;
1423 u32 rate;
1424 bool has_names;
1425
1426 if (arch_timers_present & ARCH_TIMER_TYPE_CP15) {
1427 pr_warn("multiple nodes in dt, skipping\n");
1428 return 0;
1429 }
1430
1431 arch_timers_present |= ARCH_TIMER_TYPE_CP15;
1432
1433 has_names = of_property_read_bool(np, propname: "interrupt-names");
1434
1435 for (i = ARCH_TIMER_PHYS_SECURE_PPI; i < ARCH_TIMER_MAX_TIMER_PPI; i++) {
1436 if (has_names)
1437 irq = of_irq_get_byname(dev: np, name: arch_timer_ppi_names[i]);
1438 else
1439 irq = of_irq_get(dev: np, index: i);
1440 if (irq > 0)
1441 arch_timer_ppi[i] = irq;
1442 }
1443
1444 arch_timer_populate_kvm_info();
1445
1446 rate = arch_timer_get_cntfrq();
1447 arch_timer_of_configure_rate(rate, np);
1448
1449 arch_timer_c3stop = !of_property_read_bool(np, propname: "always-on");
1450
1451 /* Check for globally applicable workarounds */
1452 arch_timer_check_ool_workaround(ate_match_dt, np);
1453
1454 /*
1455 * If we cannot rely on firmware initializing the timer registers then
1456 * we should use the physical timers instead.
1457 */
1458 if (IS_ENABLED(CONFIG_ARM) &&
1459 of_property_read_bool(np, propname: "arm,cpu-registers-not-fw-configured"))
1460 arch_timer_uses_ppi = ARCH_TIMER_PHYS_SECURE_PPI;
1461 else
1462 arch_timer_uses_ppi = arch_timer_select_ppi();
1463
1464 if (!arch_timer_ppi[arch_timer_uses_ppi]) {
1465 pr_err("No interrupt available, giving up\n");
1466 return -EINVAL;
1467 }
1468
1469 /* On some systems, the counter stops ticking when in suspend. */
1470 arch_counter_suspend_stop = of_property_read_bool(np,
1471 propname: "arm,no-tick-in-suspend");
1472
1473 ret = arch_timer_register();
1474 if (ret)
1475 return ret;
1476
1477 if (arch_timer_needs_of_probing())
1478 return 0;
1479
1480 return arch_timer_common_init();
1481}
1482TIMER_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init);
1483TIMER_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init);
1484
1485static u32 __init
1486arch_timer_mem_frame_get_cntfrq(struct arch_timer_mem_frame *frame)
1487{
1488 void __iomem *base;
1489 u32 rate;
1490
1491 base = ioremap(offset: frame->cntbase, size: frame->size);
1492 if (!base) {
1493 pr_err("Unable to map frame @ %pa\n", &frame->cntbase);
1494 return 0;
1495 }
1496
1497 rate = readl_relaxed(base + CNTFRQ);
1498
1499 iounmap(addr: base);
1500
1501 return rate;
1502}
1503
1504static struct arch_timer_mem_frame * __init
1505arch_timer_mem_find_best_frame(struct arch_timer_mem *timer_mem)
1506{
1507 struct arch_timer_mem_frame *frame, *best_frame = NULL;
1508 void __iomem *cntctlbase;
1509 u32 cnttidr;
1510 int i;
1511
1512 cntctlbase = ioremap(offset: timer_mem->cntctlbase, size: timer_mem->size);
1513 if (!cntctlbase) {
1514 pr_err("Can't map CNTCTLBase @ %pa\n",
1515 &timer_mem->cntctlbase);
1516 return NULL;
1517 }
1518
1519 cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
1520
1521 /*
1522 * Try to find a virtual capable frame. Otherwise fall back to a
1523 * physical capable frame.
1524 */
1525 for (i = 0; i < ARCH_TIMER_MEM_MAX_FRAMES; i++) {
1526 u32 cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT |
1527 CNTACR_RWVT | CNTACR_RVOFF | CNTACR_RVCT;
1528
1529 frame = &timer_mem->frame[i];
1530 if (!frame->valid)
1531 continue;
1532
1533 /* Try enabling everything, and see what sticks */
1534 writel_relaxed(cntacr, cntctlbase + CNTACR(i));
1535 cntacr = readl_relaxed(cntctlbase + CNTACR(i));
1536
1537 if ((cnttidr & CNTTIDR_VIRT(i)) &&
1538 !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT))) {
1539 best_frame = frame;
1540 arch_timer_mem_use_virtual = true;
1541 break;
1542 }
1543
1544 if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
1545 continue;
1546
1547 best_frame = frame;
1548 }
1549
1550 iounmap(addr: cntctlbase);
1551
1552 return best_frame;
1553}
1554
1555static int __init
1556arch_timer_mem_frame_register(struct arch_timer_mem_frame *frame)
1557{
1558 void __iomem *base;
1559 int ret, irq = 0;
1560
1561 if (arch_timer_mem_use_virtual)
1562 irq = frame->virt_irq;
1563 else
1564 irq = frame->phys_irq;
1565
1566 if (!irq) {
1567 pr_err("Frame missing %s irq.\n",
1568 arch_timer_mem_use_virtual ? "virt" : "phys");
1569 return -EINVAL;
1570 }
1571
1572 if (!request_mem_region(frame->cntbase, frame->size,
1573 "arch_mem_timer"))
1574 return -EBUSY;
1575
1576 base = ioremap(offset: frame->cntbase, size: frame->size);
1577 if (!base) {
1578 pr_err("Can't map frame's registers\n");
1579 return -ENXIO;
1580 }
1581
1582 ret = arch_timer_mem_register(base, irq);
1583 if (ret) {
1584 iounmap(addr: base);
1585 return ret;
1586 }
1587
1588 arch_timers_present |= ARCH_TIMER_TYPE_MEM;
1589
1590 return 0;
1591}
1592
1593static int __init arch_timer_mem_of_init(struct device_node *np)
1594{
1595 struct arch_timer_mem *timer_mem;
1596 struct arch_timer_mem_frame *frame;
1597 struct device_node *frame_node;
1598 struct resource res;
1599 int ret = -EINVAL;
1600 u32 rate;
1601
1602 timer_mem = kzalloc(size: sizeof(*timer_mem), GFP_KERNEL);
1603 if (!timer_mem)
1604 return -ENOMEM;
1605
1606 if (of_address_to_resource(dev: np, index: 0, r: &res))
1607 goto out;
1608 timer_mem->cntctlbase = res.start;
1609 timer_mem->size = resource_size(res: &res);
1610
1611 for_each_available_child_of_node(np, frame_node) {
1612 u32 n;
1613 struct arch_timer_mem_frame *frame;
1614
1615 if (of_property_read_u32(np: frame_node, propname: "frame-number", out_value: &n)) {
1616 pr_err(FW_BUG "Missing frame-number.\n");
1617 of_node_put(node: frame_node);
1618 goto out;
1619 }
1620 if (n >= ARCH_TIMER_MEM_MAX_FRAMES) {
1621 pr_err(FW_BUG "Wrong frame-number, only 0-%u are permitted.\n",
1622 ARCH_TIMER_MEM_MAX_FRAMES - 1);
1623 of_node_put(node: frame_node);
1624 goto out;
1625 }
1626 frame = &timer_mem->frame[n];
1627
1628 if (frame->valid) {
1629 pr_err(FW_BUG "Duplicated frame-number.\n");
1630 of_node_put(node: frame_node);
1631 goto out;
1632 }
1633
1634 if (of_address_to_resource(dev: frame_node, index: 0, r: &res)) {
1635 of_node_put(node: frame_node);
1636 goto out;
1637 }
1638 frame->cntbase = res.start;
1639 frame->size = resource_size(res: &res);
1640
1641 frame->virt_irq = irq_of_parse_and_map(node: frame_node,
1642 index: ARCH_TIMER_VIRT_SPI);
1643 frame->phys_irq = irq_of_parse_and_map(node: frame_node,
1644 index: ARCH_TIMER_PHYS_SPI);
1645
1646 frame->valid = true;
1647 }
1648
1649 frame = arch_timer_mem_find_best_frame(timer_mem);
1650 if (!frame) {
1651 pr_err("Unable to find a suitable frame in timer @ %pa\n",
1652 &timer_mem->cntctlbase);
1653 ret = -EINVAL;
1654 goto out;
1655 }
1656
1657 rate = arch_timer_mem_frame_get_cntfrq(frame);
1658 arch_timer_of_configure_rate(rate, np);
1659
1660 ret = arch_timer_mem_frame_register(frame);
1661 if (!ret && !arch_timer_needs_of_probing())
1662 ret = arch_timer_common_init();
1663out:
1664 kfree(objp: timer_mem);
1665 return ret;
1666}
1667TIMER_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
1668 arch_timer_mem_of_init);
1669
1670#ifdef CONFIG_ACPI_GTDT
1671static int __init
1672arch_timer_mem_verify_cntfrq(struct arch_timer_mem *timer_mem)
1673{
1674 struct arch_timer_mem_frame *frame;
1675 u32 rate;
1676 int i;
1677
1678 for (i = 0; i < ARCH_TIMER_MEM_MAX_FRAMES; i++) {
1679 frame = &timer_mem->frame[i];
1680
1681 if (!frame->valid)
1682 continue;
1683
1684 rate = arch_timer_mem_frame_get_cntfrq(frame);
1685 if (rate == arch_timer_rate)
1686 continue;
1687
1688 pr_err(FW_BUG "CNTFRQ mismatch: frame @ %pa: (0x%08lx), CPU: (0x%08lx)\n",
1689 &frame->cntbase,
1690 (unsigned long)rate, (unsigned long)arch_timer_rate);
1691
1692 return -EINVAL;
1693 }
1694
1695 return 0;
1696}
1697
1698static int __init arch_timer_mem_acpi_init(int platform_timer_count)
1699{
1700 struct arch_timer_mem *timers, *timer;
1701 struct arch_timer_mem_frame *frame, *best_frame = NULL;
1702 int timer_count, i, ret = 0;
1703
1704 timers = kcalloc(platform_timer_count, sizeof(*timers),
1705 GFP_KERNEL);
1706 if (!timers)
1707 return -ENOMEM;
1708
1709 ret = acpi_arch_timer_mem_init(timers, &timer_count);
1710 if (ret || !timer_count)
1711 goto out;
1712
1713 /*
1714 * While unlikely, it's theoretically possible that none of the frames
1715 * in a timer expose the combination of feature we want.
1716 */
1717 for (i = 0; i < timer_count; i++) {
1718 timer = &timers[i];
1719
1720 frame = arch_timer_mem_find_best_frame(timer);
1721 if (!best_frame)
1722 best_frame = frame;
1723
1724 ret = arch_timer_mem_verify_cntfrq(timer);
1725 if (ret) {
1726 pr_err("Disabling MMIO timers due to CNTFRQ mismatch\n");
1727 goto out;
1728 }
1729
1730 if (!best_frame) /* implies !frame */
1731 /*
1732 * Only complain about missing suitable frames if we
1733 * haven't already found one in a previous iteration.
1734 */
1735 pr_err("Unable to find a suitable frame in timer @ %pa\n",
1736 &timer->cntctlbase);
1737 }
1738
1739 if (best_frame)
1740 ret = arch_timer_mem_frame_register(best_frame);
1741out:
1742 kfree(timers);
1743 return ret;
1744}
1745
1746/* Initialize per-processor generic timer and memory-mapped timer(if present) */
1747static int __init arch_timer_acpi_init(struct acpi_table_header *table)
1748{
1749 int ret, platform_timer_count;
1750
1751 if (arch_timers_present & ARCH_TIMER_TYPE_CP15) {
1752 pr_warn("already initialized, skipping\n");
1753 return -EINVAL;
1754 }
1755
1756 arch_timers_present |= ARCH_TIMER_TYPE_CP15;
1757
1758 ret = acpi_gtdt_init(table, &platform_timer_count);
1759 if (ret)
1760 return ret;
1761
1762 arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI] =
1763 acpi_gtdt_map_ppi(ARCH_TIMER_PHYS_NONSECURE_PPI);
1764
1765 arch_timer_ppi[ARCH_TIMER_VIRT_PPI] =
1766 acpi_gtdt_map_ppi(ARCH_TIMER_VIRT_PPI);
1767
1768 arch_timer_ppi[ARCH_TIMER_HYP_PPI] =
1769 acpi_gtdt_map_ppi(ARCH_TIMER_HYP_PPI);
1770
1771 arch_timer_populate_kvm_info();
1772
1773 /*
1774 * When probing via ACPI, we have no mechanism to override the sysreg
1775 * CNTFRQ value. This *must* be correct.
1776 */
1777 arch_timer_rate = arch_timer_get_cntfrq();
1778 ret = validate_timer_rate();
1779 if (ret) {
1780 pr_err(FW_BUG "frequency not available.\n");
1781 return ret;
1782 }
1783
1784 arch_timer_uses_ppi = arch_timer_select_ppi();
1785 if (!arch_timer_ppi[arch_timer_uses_ppi]) {
1786 pr_err("No interrupt available, giving up\n");
1787 return -EINVAL;
1788 }
1789
1790 /* Always-on capability */
1791 arch_timer_c3stop = acpi_gtdt_c3stop(arch_timer_uses_ppi);
1792
1793 /* Check for globally applicable workarounds */
1794 arch_timer_check_ool_workaround(ate_match_acpi_oem_info, table);
1795
1796 ret = arch_timer_register();
1797 if (ret)
1798 return ret;
1799
1800 if (platform_timer_count &&
1801 arch_timer_mem_acpi_init(platform_timer_count))
1802 pr_err("Failed to initialize memory-mapped timer.\n");
1803
1804 return arch_timer_common_init();
1805}
1806TIMER_ACPI_DECLARE(arch_timer, ACPI_SIG_GTDT, arch_timer_acpi_init);
1807#endif
1808
1809int kvm_arch_ptp_get_crosststamp(u64 *cycle, struct timespec64 *ts,
1810 struct clocksource **cs)
1811{
1812 struct arm_smccc_res hvc_res;
1813 u32 ptp_counter;
1814 ktime_t ktime;
1815
1816 if (!IS_ENABLED(CONFIG_HAVE_ARM_SMCCC_DISCOVERY))
1817 return -EOPNOTSUPP;
1818
1819 if (arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI)
1820 ptp_counter = KVM_PTP_VIRT_COUNTER;
1821 else
1822 ptp_counter = KVM_PTP_PHYS_COUNTER;
1823
1824 arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID,
1825 ptp_counter, &hvc_res);
1826
1827 if ((int)(hvc_res.a0) < 0)
1828 return -EOPNOTSUPP;
1829
1830 ktime = (u64)hvc_res.a0 << 32 | hvc_res.a1;
1831 *ts = ktime_to_timespec64(ktime);
1832 if (cycle)
1833 *cycle = (u64)hvc_res.a2 << 32 | hvc_res.a3;
1834 if (cs)
1835 *cs = &clocksource_counter;
1836
1837 return 0;
1838}
1839EXPORT_SYMBOL_GPL(kvm_arch_ptp_get_crosststamp);
1840

source code of linux/drivers/clocksource/arm_arch_timer.c