GNU Linux-libre 6.9.1-gnu
[releases.git] / drivers / clocksource / arm_arch_timer.c
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
62 static unsigned arch_timers_present __initdata;
63
64 struct arch_timer {
65         void __iomem *base;
66         struct clock_event_device evt;
67 };
68
69 static struct arch_timer *arch_timer_mem __ro_after_init;
70
71 #define to_arch_timer(e) container_of(e, struct arch_timer, evt)
72
73 static u32 arch_timer_rate __ro_after_init;
74 static int arch_timer_ppi[ARCH_TIMER_MAX_TIMER_PPI] __ro_after_init;
75
76 static 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
84 static struct clock_event_device __percpu *arch_timer_evt;
85
86 static enum arch_timer_ppi_nr arch_timer_uses_ppi __ro_after_init = ARCH_TIMER_VIRT_PPI;
87 static bool arch_timer_c3stop __ro_after_init;
88 static bool arch_timer_mem_use_virtual __ro_after_init;
89 static bool arch_counter_suspend_stop __ro_after_init;
90 #ifdef CONFIG_GENERIC_GETTIMEOFDAY
91 static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
92 #else
93 static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_NONE;
94 #endif /* CONFIG_GENERIC_GETTIMEOFDAY */
95
96 static cpumask_t evtstrm_available = CPU_MASK_NONE;
97 static bool evtstrm_enable __ro_after_init = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM);
98
99 static int __init early_evtstrm_cfg(char *buf)
100 {
101         return kstrtobool(buf, &evtstrm_enable);
102 }
103 early_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  */
113 static 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
125 static __always_inline
126 void 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
163 static __always_inline
164 u32 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
194 static noinstr u64 raw_counter_get_cntpct_stable(void)
195 {
196         return __arch_counter_get_cntpct_stable();
197 }
198
199 static 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
208 static noinstr u64 arch_counter_get_cntpct(void)
209 {
210         return __arch_counter_get_cntpct();
211 }
212
213 static noinstr u64 raw_counter_get_cntvct_stable(void)
214 {
215         return __arch_counter_get_cntvct_stable();
216 }
217
218 static 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
227 static 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  */
238 u64 (*arch_timer_read_counter)(void) __ro_after_init = arch_counter_get_cntvct;
239 EXPORT_SYMBOL_GPL(arch_timer_read_counter);
240
241 static u64 arch_counter_read(struct clocksource *cs)
242 {
243         return arch_timer_read_counter();
244 }
245
246 static u64 arch_counter_read_cc(const struct cyclecounter *cc)
247 {
248         return arch_timer_read_counter();
249 }
250
251 static 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
259 static struct cyclecounter cyclecounter __ro_after_init = {
260         .read   = arch_counter_read_cc,
261 };
262
263 struct 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
288 static u64 notrace fsl_a008585_read_cntpct_el0(void)
289 {
290         return __fsl_a008585_read_reg(cntpct_el0);
291 }
292
293 static 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
324 static u64 notrace hisi_161010101_read_cntpct_el0(void)
325 {
326         return __hisi_161010101_read_reg(cntpct_el0);
327 }
328
329 static u64 notrace hisi_161010101_read_cntvct_el0(void)
330 {
331         return __hisi_161010101_read_reg(cntvct_el0);
332 }
333
334 static 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
359 static 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
368 static 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
399 static u64 notrace sun50i_a64_read_cntpct_el0(void)
400 {
401         return __sun50i_a64_read_reg(cntpct_el0);
402 }
403
404 static 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
411 DEFINE_PER_CPU(const struct arch_timer_erratum_workaround *, timer_unstable_counter_workaround);
412 EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround);
413
414 static 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  */
420 static __always_inline
421 void 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
442 static __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
449 static __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
456 static 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
520 typedef bool (*ate_match_fn_t)(const struct arch_timer_erratum_workaround *,
521                                const void *);
522
523 static
524 bool 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
532 static
533 bool 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
540 static
541 bool 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
561 static const struct arch_timer_erratum_workaround *
562 arch_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
579 static
580 void 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
610 static 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
650 static bool arch_timer_this_cpu_has_cntvct_wa(void)
651 {
652         return has_erratum_handler(read_cntvct_el0);
653 }
654
655 static 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
665 static __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, ARCH_TIMER_REG_CTRL, evt);
671         if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
672                 ctrl |= ARCH_TIMER_CTRL_IT_MASK;
673                 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, evt);
674                 evt->event_handler(evt);
675                 return IRQ_HANDLED;
676         }
677
678         return IRQ_NONE;
679 }
680
681 static 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
688 static 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
695 static 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
702 static 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
709 static __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, ARCH_TIMER_REG_CTRL, clk);
715         ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
716         arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
717
718         return 0;
719 }
720
721 static int arch_timer_shutdown_virt(struct clock_event_device *clk)
722 {
723         return arch_timer_shutdown(ARCH_TIMER_VIRT_ACCESS, clk);
724 }
725
726 static int arch_timer_shutdown_phys(struct clock_event_device *clk)
727 {
728         return arch_timer_shutdown(ARCH_TIMER_PHYS_ACCESS, clk);
729 }
730
731 static 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
736 static 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
741 static __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, 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, ARCH_TIMER_REG_CVAL, evt + cnt, clk);
757         arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
758 }
759
760 static 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
767 static 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
774 static 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
787 static __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, 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, ARCH_TIMER_REG_CTRL, 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(timer, CNTVCT_LO);
807         else
808                 cnt = arch_counter_get_cnt_mem(timer, CNTPCT_LO);
809
810         arch_timer_reg_write(access, ARCH_TIMER_REG_CVAL, evt + cnt, clk);
811         arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
812 }
813
814 static 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
821 static 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
828 static 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
853 static 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(clk, arch_timer_rate, 0xf, max_delta);
913 }
914
915 static 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(), &evtstrm_available);
935 }
936
937 static 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(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
959 static int arch_timer_evtstrm_starting_cpu(unsigned int cpu)
960 {
961         arch_timer_configure_evtstream();
962         return 0;
963 }
964
965 static int arch_timer_evtstrm_dying_cpu(unsigned int cpu)
966 {
967         cpumask_clear_cpu(smp_processor_id(), &evtstrm_available);
968         return 0;
969 }
970
971 static int __init arch_timer_evtstrm_register(void)
972 {
973         if (!arch_timer_evt || !evtstrm_enable)
974                 return 0;
975
976         return cpuhp_setup_state(CPUHP_AP_ARM_ARCH_TIMER_EVTSTRM_STARTING,
977                                  "clockevents/arm/arch_timer_evtstrm:starting",
978                                  arch_timer_evtstrm_starting_cpu,
979                                  arch_timer_evtstrm_dying_cpu);
980 }
981 core_initcall(arch_timer_evtstrm_register);
982
983 static 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
1008 static 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
1014 static 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
1027 static 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(arch_timer_ppi[arch_timer_uses_ppi]);
1035         enable_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi], flags);
1036
1037         if (arch_timer_has_nonsecure_ppi()) {
1038                 flags = check_ppi_trigger(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
1039                 enable_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI],
1040                                   flags);
1041         }
1042
1043         arch_counter_set_user_access();
1044
1045         return 0;
1046 }
1047
1048 static 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  */
1064 static 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, "clock-frequency", &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
1078 static 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
1096 u32 arch_timer_get_rate(void)
1097 {
1098         return arch_timer_rate;
1099 }
1100
1101 bool 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(), &evtstrm_available);
1109 }
1110
1111 static noinstr u64 arch_counter_get_cntvct_mem(void)
1112 {
1113         return arch_counter_get_cnt_mem(arch_timer_mem, CNTVCT_LO);
1114 }
1115
1116 static struct arch_timer_kvm_info arch_timer_kvm_info;
1117
1118 struct arch_timer_kvm_info *arch_timer_get_kvm_info(void)
1119 {
1120         return &arch_timer_kvm_info;
1121 }
1122
1123 static 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(&clocksource_counter, arch_timer_rate);
1167         cyclecounter.mult = clocksource_counter.mult;
1168         cyclecounter.shift = clocksource_counter.shift;
1169         timecounter_init(&arch_timer_kvm_info.timecounter,
1170                          &cyclecounter, start_count);
1171
1172         sched_clock_register(scr, width, arch_timer_rate);
1173 }
1174
1175 static 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(arch_timer_ppi[arch_timer_uses_ppi]);
1180         if (arch_timer_has_nonsecure_ppi())
1181                 disable_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
1182
1183         clk->set_state_shutdown(clk);
1184 }
1185
1186 static 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
1195 static DEFINE_PER_CPU(unsigned long, saved_cntkctl);
1196 static 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
1212 static struct notifier_block arch_timer_cpu_pm_notifier = {
1213         .notifier_call = arch_timer_cpu_pm_notify,
1214 };
1215
1216 static int __init arch_timer_cpu_pm_init(void)
1217 {
1218         return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier);
1219 }
1220
1221 static 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
1227 static int __init arch_timer_cpu_pm_init(void)
1228 {
1229         return 0;
1230 }
1231
1232 static void __init arch_timer_cpu_pm_deinit(void)
1233 {
1234 }
1235 #endif
1236
1237 static 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(ppi, arch_timer_handler_virt,
1252                                          "arch_timer", arch_timer_evt);
1253                 break;
1254         case ARCH_TIMER_PHYS_SECURE_PPI:
1255         case ARCH_TIMER_PHYS_NONSECURE_PPI:
1256                 err = request_percpu_irq(ppi, arch_timer_handler_phys,
1257                                          "arch_timer", 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(ppi, arch_timer_handler_phys,
1261                                                  "arch_timer", 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(ppi, arch_timer_handler_phys,
1269                                          "arch_timer", 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(CPUHP_AP_ARM_ARCH_TIMER_STARTING,
1286                                 "clockevents/arm/arch_timer:starting",
1287                                 arch_timer_starting_cpu, arch_timer_dying_cpu);
1288         if (err)
1289                 goto out_unreg_cpupm;
1290         return 0;
1291
1292 out_unreg_cpupm:
1293         arch_timer_cpu_pm_deinit();
1294
1295 out_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
1301 out_free:
1302         free_percpu(arch_timer_evt);
1303         arch_timer_evt = NULL;
1304 out:
1305         return err;
1306 }
1307
1308 static 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(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, &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, func, IRQF_TIMER, "arch_mem_timer", &arch_timer_mem->evt);
1327         if (ret) {
1328                 pr_err("Failed to request mem timer irq\n");
1329                 kfree(arch_timer_mem);
1330                 arch_timer_mem = NULL;
1331         }
1332
1333         return ret;
1334 }
1335
1336 static const struct of_device_id arch_timer_of_match[] __initconst = {
1337         { .compatible   = "arm,armv7-timer",    },
1338         { .compatible   = "arm,armv8-timer",    },
1339         {},
1340 };
1341
1342 static const struct of_device_id arch_timer_mem_of_match[] __initconst = {
1343         { .compatible   = "arm,armv7-timer-mem", },
1344         {},
1345 };
1346
1347 static 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, arch_timer_mem_of_match);
1363         else
1364                 dn = of_find_matching_node(NULL, arch_timer_of_match);
1365
1366         if (dn && of_device_is_available(dn))
1367                 needs_probing = true;
1368
1369         of_node_put(dn);
1370
1371         return needs_probing;
1372 }
1373
1374 static int __init arch_timer_common_init(void)
1375 {
1376         arch_timer_banner(arch_timers_present);
1377         arch_counter_register(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  */
1399 static 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
1413 static 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
1420 static 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, "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(np, arch_timer_ppi_names[i]);
1438                 else
1439                         irq = of_irq_get(np, 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, "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, "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                                                          "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 }
1482 TIMER_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init);
1483 TIMER_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init);
1484
1485 static u32 __init
1486 arch_timer_mem_frame_get_cntfrq(struct arch_timer_mem_frame *frame)
1487 {
1488         void __iomem *base;
1489         u32 rate;
1490
1491         base = ioremap(frame->cntbase, 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(base);
1500
1501         return rate;
1502 }
1503
1504 static struct arch_timer_mem_frame * __init
1505 arch_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(timer_mem->cntctlbase, 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(cntctlbase);
1551
1552         return best_frame;
1553 }
1554
1555 static int __init
1556 arch_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(frame->cntbase, 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(base);
1585                 return ret;
1586         }
1587
1588         arch_timers_present |= ARCH_TIMER_TYPE_MEM;
1589
1590         return 0;
1591 }
1592
1593 static 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(sizeof(*timer_mem), GFP_KERNEL);
1603         if (!timer_mem)
1604                 return -ENOMEM;
1605
1606         if (of_address_to_resource(np, 0, &res))
1607                 goto out;
1608         timer_mem->cntctlbase = res.start;
1609         timer_mem->size = resource_size(&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(frame_node, "frame-number", &n)) {
1616                         pr_err(FW_BUG "Missing frame-number.\n");
1617                         of_node_put(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(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(frame_node);
1631                         goto out;
1632                 }
1633
1634                 if (of_address_to_resource(frame_node, 0, &res)) {
1635                         of_node_put(frame_node);
1636                         goto out;
1637                 }
1638                 frame->cntbase = res.start;
1639                 frame->size = resource_size(&res);
1640
1641                 frame->virt_irq = irq_of_parse_and_map(frame_node,
1642                                                        ARCH_TIMER_VIRT_SPI);
1643                 frame->phys_irq = irq_of_parse_and_map(frame_node,
1644                                                        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();
1663 out:
1664         kfree(timer_mem);
1665         return ret;
1666 }
1667 TIMER_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
1668                        arch_timer_mem_of_init);
1669
1670 #ifdef CONFIG_ACPI_GTDT
1671 static int __init
1672 arch_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
1698 static 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);
1741 out:
1742         kfree(timers);
1743         return ret;
1744 }
1745
1746 /* Initialize per-processor generic timer and memory-mapped timer(if present) */
1747 static 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 }
1806 TIMER_ACPI_DECLARE(arch_timer, ACPI_SIG_GTDT, arch_timer_acpi_init);
1807 #endif
1808
1809 int kvm_arch_ptp_get_crosststamp(u64 *cycle, struct timespec64 *ts,
1810                                  enum clocksource_ids *cs_id)
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_id)
1835                 *cs_id = CSID_ARM_ARCH_COUNTER;
1836
1837         return 0;
1838 }
1839 EXPORT_SYMBOL_GPL(kvm_arch_ptp_get_crosststamp);