xref: /openbmc/linux/arch/arm/kernel/perf_event_v6.c (revision a44e4f3a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ARMv6 Performance counter handling code.
4  *
5  * Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles
6  *
7  * ARMv6 has 2 configurable performance counters and a single cycle counter.
8  * They all share a single reset bit but can be written to zero so we can use
9  * that for a reset.
10  *
11  * The counters can't be individually enabled or disabled so when we remove
12  * one event and replace it with another we could get spurious counts from the
13  * wrong event. However, we can take advantage of the fact that the
14  * performance counters can export events to the event bus, and the event bus
15  * itself can be monitored. This requires that we *don't* export the events to
16  * the event bus. The procedure for disabling a configurable counter is:
17  *	- change the counter to count the ETMEXTOUT[0] signal (0x20). This
18  *	  effectively stops the counter from counting.
19  *	- disable the counter's interrupt generation (each counter has it's
20  *	  own interrupt enable bit).
21  * Once stopped, the counter value can be written as 0 to reset.
22  *
23  * To enable a counter:
24  *	- enable the counter's interrupt generation.
25  *	- set the new event type.
26  *
27  * Note: the dedicated cycle counter only counts cycles and can't be
28  * enabled/disabled independently of the others. When we want to disable the
29  * cycle counter, we have to just disable the interrupt reporting and start
30  * ignoring that counter. When re-enabling, we have to reset the value and
31  * enable the interrupt.
32  */
33 
34 #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K)
35 
36 #include <asm/cputype.h>
37 #include <asm/irq_regs.h>
38 
39 #include <linux/of.h>
40 #include <linux/perf/arm_pmu.h>
41 #include <linux/platform_device.h>
42 
43 enum armv6_perf_types {
44 	ARMV6_PERFCTR_ICACHE_MISS	    = 0x0,
45 	ARMV6_PERFCTR_IBUF_STALL	    = 0x1,
46 	ARMV6_PERFCTR_DDEP_STALL	    = 0x2,
47 	ARMV6_PERFCTR_ITLB_MISS		    = 0x3,
48 	ARMV6_PERFCTR_DTLB_MISS		    = 0x4,
49 	ARMV6_PERFCTR_BR_EXEC		    = 0x5,
50 	ARMV6_PERFCTR_BR_MISPREDICT	    = 0x6,
51 	ARMV6_PERFCTR_INSTR_EXEC	    = 0x7,
52 	ARMV6_PERFCTR_DCACHE_HIT	    = 0x9,
53 	ARMV6_PERFCTR_DCACHE_ACCESS	    = 0xA,
54 	ARMV6_PERFCTR_DCACHE_MISS	    = 0xB,
55 	ARMV6_PERFCTR_DCACHE_WBACK	    = 0xC,
56 	ARMV6_PERFCTR_SW_PC_CHANGE	    = 0xD,
57 	ARMV6_PERFCTR_MAIN_TLB_MISS	    = 0xF,
58 	ARMV6_PERFCTR_EXPL_D_ACCESS	    = 0x10,
59 	ARMV6_PERFCTR_LSU_FULL_STALL	    = 0x11,
60 	ARMV6_PERFCTR_WBUF_DRAINED	    = 0x12,
61 	ARMV6_PERFCTR_CPU_CYCLES	    = 0xFF,
62 	ARMV6_PERFCTR_NOP		    = 0x20,
63 };
64 
65 enum armv6_counters {
66 	ARMV6_CYCLE_COUNTER = 0,
67 	ARMV6_COUNTER0,
68 	ARMV6_COUNTER1,
69 };
70 
71 /*
72  * The hardware events that we support. We do support cache operations but
73  * we have harvard caches and no way to combine instruction and data
74  * accesses/misses in hardware.
75  */
76 static const unsigned armv6_perf_map[PERF_COUNT_HW_MAX] = {
77 	PERF_MAP_ALL_UNSUPPORTED,
78 	[PERF_COUNT_HW_CPU_CYCLES]		= ARMV6_PERFCTR_CPU_CYCLES,
79 	[PERF_COUNT_HW_INSTRUCTIONS]		= ARMV6_PERFCTR_INSTR_EXEC,
80 	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= ARMV6_PERFCTR_BR_EXEC,
81 	[PERF_COUNT_HW_BRANCH_MISSES]		= ARMV6_PERFCTR_BR_MISPREDICT,
82 	[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= ARMV6_PERFCTR_IBUF_STALL,
83 	[PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= ARMV6_PERFCTR_LSU_FULL_STALL,
84 };
85 
86 static const unsigned armv6_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
87 					  [PERF_COUNT_HW_CACHE_OP_MAX]
88 					  [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
89 	PERF_CACHE_MAP_ALL_UNSUPPORTED,
90 
91 	/*
92 	 * The performance counters don't differentiate between read and write
93 	 * accesses/misses so this isn't strictly correct, but it's the best we
94 	 * can do. Writes and reads get combined.
95 	 */
96 	[C(L1D)][C(OP_READ)][C(RESULT_ACCESS)]	= ARMV6_PERFCTR_DCACHE_ACCESS,
97 	[C(L1D)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6_PERFCTR_DCACHE_MISS,
98 	[C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)]	= ARMV6_PERFCTR_DCACHE_ACCESS,
99 	[C(L1D)][C(OP_WRITE)][C(RESULT_MISS)]	= ARMV6_PERFCTR_DCACHE_MISS,
100 
101 	[C(L1I)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6_PERFCTR_ICACHE_MISS,
102 
103 	/*
104 	 * The ARM performance counters can count micro DTLB misses, micro ITLB
105 	 * misses and main TLB misses. There isn't an event for TLB misses, so
106 	 * use the micro misses here and if users want the main TLB misses they
107 	 * can use a raw counter.
108 	 */
109 	[C(DTLB)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6_PERFCTR_DTLB_MISS,
110 	[C(DTLB)][C(OP_WRITE)][C(RESULT_MISS)]	= ARMV6_PERFCTR_DTLB_MISS,
111 
112 	[C(ITLB)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6_PERFCTR_ITLB_MISS,
113 	[C(ITLB)][C(OP_WRITE)][C(RESULT_MISS)]	= ARMV6_PERFCTR_ITLB_MISS,
114 };
115 
116 enum armv6mpcore_perf_types {
117 	ARMV6MPCORE_PERFCTR_ICACHE_MISS	    = 0x0,
118 	ARMV6MPCORE_PERFCTR_IBUF_STALL	    = 0x1,
119 	ARMV6MPCORE_PERFCTR_DDEP_STALL	    = 0x2,
120 	ARMV6MPCORE_PERFCTR_ITLB_MISS	    = 0x3,
121 	ARMV6MPCORE_PERFCTR_DTLB_MISS	    = 0x4,
122 	ARMV6MPCORE_PERFCTR_BR_EXEC	    = 0x5,
123 	ARMV6MPCORE_PERFCTR_BR_NOTPREDICT   = 0x6,
124 	ARMV6MPCORE_PERFCTR_BR_MISPREDICT   = 0x7,
125 	ARMV6MPCORE_PERFCTR_INSTR_EXEC	    = 0x8,
126 	ARMV6MPCORE_PERFCTR_DCACHE_RDACCESS = 0xA,
127 	ARMV6MPCORE_PERFCTR_DCACHE_RDMISS   = 0xB,
128 	ARMV6MPCORE_PERFCTR_DCACHE_WRACCESS = 0xC,
129 	ARMV6MPCORE_PERFCTR_DCACHE_WRMISS   = 0xD,
130 	ARMV6MPCORE_PERFCTR_DCACHE_EVICTION = 0xE,
131 	ARMV6MPCORE_PERFCTR_SW_PC_CHANGE    = 0xF,
132 	ARMV6MPCORE_PERFCTR_MAIN_TLB_MISS   = 0x10,
133 	ARMV6MPCORE_PERFCTR_EXPL_MEM_ACCESS = 0x11,
134 	ARMV6MPCORE_PERFCTR_LSU_FULL_STALL  = 0x12,
135 	ARMV6MPCORE_PERFCTR_WBUF_DRAINED    = 0x13,
136 	ARMV6MPCORE_PERFCTR_CPU_CYCLES	    = 0xFF,
137 };
138 
139 /*
140  * The hardware events that we support. We do support cache operations but
141  * we have harvard caches and no way to combine instruction and data
142  * accesses/misses in hardware.
143  */
144 static const unsigned armv6mpcore_perf_map[PERF_COUNT_HW_MAX] = {
145 	PERF_MAP_ALL_UNSUPPORTED,
146 	[PERF_COUNT_HW_CPU_CYCLES]		= ARMV6MPCORE_PERFCTR_CPU_CYCLES,
147 	[PERF_COUNT_HW_INSTRUCTIONS]		= ARMV6MPCORE_PERFCTR_INSTR_EXEC,
148 	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= ARMV6MPCORE_PERFCTR_BR_EXEC,
149 	[PERF_COUNT_HW_BRANCH_MISSES]		= ARMV6MPCORE_PERFCTR_BR_MISPREDICT,
150 	[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= ARMV6MPCORE_PERFCTR_IBUF_STALL,
151 	[PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= ARMV6MPCORE_PERFCTR_LSU_FULL_STALL,
152 };
153 
154 static const unsigned armv6mpcore_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
155 					[PERF_COUNT_HW_CACHE_OP_MAX]
156 					[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
157 	PERF_CACHE_MAP_ALL_UNSUPPORTED,
158 
159 	[C(L1D)][C(OP_READ)][C(RESULT_ACCESS)]	= ARMV6MPCORE_PERFCTR_DCACHE_RDACCESS,
160 	[C(L1D)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_DCACHE_RDMISS,
161 	[C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)]	= ARMV6MPCORE_PERFCTR_DCACHE_WRACCESS,
162 	[C(L1D)][C(OP_WRITE)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_DCACHE_WRMISS,
163 
164 	[C(L1I)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_ICACHE_MISS,
165 
166 	/*
167 	 * The ARM performance counters can count micro DTLB misses, micro ITLB
168 	 * misses and main TLB misses. There isn't an event for TLB misses, so
169 	 * use the micro misses here and if users want the main TLB misses they
170 	 * can use a raw counter.
171 	 */
172 	[C(DTLB)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_DTLB_MISS,
173 	[C(DTLB)][C(OP_WRITE)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_DTLB_MISS,
174 
175 	[C(ITLB)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_ITLB_MISS,
176 	[C(ITLB)][C(OP_WRITE)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_ITLB_MISS,
177 };
178 
179 static inline unsigned long
180 armv6_pmcr_read(void)
181 {
182 	u32 val;
183 	asm volatile("mrc   p15, 0, %0, c15, c12, 0" : "=r"(val));
184 	return val;
185 }
186 
187 static inline void
188 armv6_pmcr_write(unsigned long val)
189 {
190 	asm volatile("mcr   p15, 0, %0, c15, c12, 0" : : "r"(val));
191 }
192 
193 #define ARMV6_PMCR_ENABLE		(1 << 0)
194 #define ARMV6_PMCR_CTR01_RESET		(1 << 1)
195 #define ARMV6_PMCR_CCOUNT_RESET		(1 << 2)
196 #define ARMV6_PMCR_CCOUNT_DIV		(1 << 3)
197 #define ARMV6_PMCR_COUNT0_IEN		(1 << 4)
198 #define ARMV6_PMCR_COUNT1_IEN		(1 << 5)
199 #define ARMV6_PMCR_CCOUNT_IEN		(1 << 6)
200 #define ARMV6_PMCR_COUNT0_OVERFLOW	(1 << 8)
201 #define ARMV6_PMCR_COUNT1_OVERFLOW	(1 << 9)
202 #define ARMV6_PMCR_CCOUNT_OVERFLOW	(1 << 10)
203 #define ARMV6_PMCR_EVT_COUNT0_SHIFT	20
204 #define ARMV6_PMCR_EVT_COUNT0_MASK	(0xFF << ARMV6_PMCR_EVT_COUNT0_SHIFT)
205 #define ARMV6_PMCR_EVT_COUNT1_SHIFT	12
206 #define ARMV6_PMCR_EVT_COUNT1_MASK	(0xFF << ARMV6_PMCR_EVT_COUNT1_SHIFT)
207 
208 #define ARMV6_PMCR_OVERFLOWED_MASK \
209 	(ARMV6_PMCR_COUNT0_OVERFLOW | ARMV6_PMCR_COUNT1_OVERFLOW | \
210 	 ARMV6_PMCR_CCOUNT_OVERFLOW)
211 
212 static inline int
213 armv6_pmcr_has_overflowed(unsigned long pmcr)
214 {
215 	return pmcr & ARMV6_PMCR_OVERFLOWED_MASK;
216 }
217 
218 static inline int
219 armv6_pmcr_counter_has_overflowed(unsigned long pmcr,
220 				  enum armv6_counters counter)
221 {
222 	int ret = 0;
223 
224 	if (ARMV6_CYCLE_COUNTER == counter)
225 		ret = pmcr & ARMV6_PMCR_CCOUNT_OVERFLOW;
226 	else if (ARMV6_COUNTER0 == counter)
227 		ret = pmcr & ARMV6_PMCR_COUNT0_OVERFLOW;
228 	else if (ARMV6_COUNTER1 == counter)
229 		ret = pmcr & ARMV6_PMCR_COUNT1_OVERFLOW;
230 	else
231 		WARN_ONCE(1, "invalid counter number (%d)\n", counter);
232 
233 	return ret;
234 }
235 
236 static inline u64 armv6pmu_read_counter(struct perf_event *event)
237 {
238 	struct hw_perf_event *hwc = &event->hw;
239 	int counter = hwc->idx;
240 	unsigned long value = 0;
241 
242 	if (ARMV6_CYCLE_COUNTER == counter)
243 		asm volatile("mrc   p15, 0, %0, c15, c12, 1" : "=r"(value));
244 	else if (ARMV6_COUNTER0 == counter)
245 		asm volatile("mrc   p15, 0, %0, c15, c12, 2" : "=r"(value));
246 	else if (ARMV6_COUNTER1 == counter)
247 		asm volatile("mrc   p15, 0, %0, c15, c12, 3" : "=r"(value));
248 	else
249 		WARN_ONCE(1, "invalid counter number (%d)\n", counter);
250 
251 	return value;
252 }
253 
254 static inline void armv6pmu_write_counter(struct perf_event *event, u64 value)
255 {
256 	struct hw_perf_event *hwc = &event->hw;
257 	int counter = hwc->idx;
258 
259 	if (ARMV6_CYCLE_COUNTER == counter)
260 		asm volatile("mcr   p15, 0, %0, c15, c12, 1" : : "r"(value));
261 	else if (ARMV6_COUNTER0 == counter)
262 		asm volatile("mcr   p15, 0, %0, c15, c12, 2" : : "r"(value));
263 	else if (ARMV6_COUNTER1 == counter)
264 		asm volatile("mcr   p15, 0, %0, c15, c12, 3" : : "r"(value));
265 	else
266 		WARN_ONCE(1, "invalid counter number (%d)\n", counter);
267 }
268 
269 static void armv6pmu_enable_event(struct perf_event *event)
270 {
271 	unsigned long val, mask, evt, flags;
272 	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
273 	struct hw_perf_event *hwc = &event->hw;
274 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
275 	int idx = hwc->idx;
276 
277 	if (ARMV6_CYCLE_COUNTER == idx) {
278 		mask	= 0;
279 		evt	= ARMV6_PMCR_CCOUNT_IEN;
280 	} else if (ARMV6_COUNTER0 == idx) {
281 		mask	= ARMV6_PMCR_EVT_COUNT0_MASK;
282 		evt	= (hwc->config_base << ARMV6_PMCR_EVT_COUNT0_SHIFT) |
283 			  ARMV6_PMCR_COUNT0_IEN;
284 	} else if (ARMV6_COUNTER1 == idx) {
285 		mask	= ARMV6_PMCR_EVT_COUNT1_MASK;
286 		evt	= (hwc->config_base << ARMV6_PMCR_EVT_COUNT1_SHIFT) |
287 			  ARMV6_PMCR_COUNT1_IEN;
288 	} else {
289 		WARN_ONCE(1, "invalid counter number (%d)\n", idx);
290 		return;
291 	}
292 
293 	/*
294 	 * Mask out the current event and set the counter to count the event
295 	 * that we're interested in.
296 	 */
297 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
298 	val = armv6_pmcr_read();
299 	val &= ~mask;
300 	val |= evt;
301 	armv6_pmcr_write(val);
302 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
303 }
304 
305 static irqreturn_t
306 armv6pmu_handle_irq(struct arm_pmu *cpu_pmu)
307 {
308 	unsigned long pmcr = armv6_pmcr_read();
309 	struct perf_sample_data data;
310 	struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
311 	struct pt_regs *regs;
312 	int idx;
313 
314 	if (!armv6_pmcr_has_overflowed(pmcr))
315 		return IRQ_NONE;
316 
317 	regs = get_irq_regs();
318 
319 	/*
320 	 * The interrupts are cleared by writing the overflow flags back to
321 	 * the control register. All of the other bits don't have any effect
322 	 * if they are rewritten, so write the whole value back.
323 	 */
324 	armv6_pmcr_write(pmcr);
325 
326 	for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
327 		struct perf_event *event = cpuc->events[idx];
328 		struct hw_perf_event *hwc;
329 
330 		/* Ignore if we don't have an event. */
331 		if (!event)
332 			continue;
333 
334 		/*
335 		 * We have a single interrupt for all counters. Check that
336 		 * each counter has overflowed before we process it.
337 		 */
338 		if (!armv6_pmcr_counter_has_overflowed(pmcr, idx))
339 			continue;
340 
341 		hwc = &event->hw;
342 		armpmu_event_update(event);
343 		perf_sample_data_init(&data, 0, hwc->last_period);
344 		if (!armpmu_event_set_period(event))
345 			continue;
346 
347 		if (perf_event_overflow(event, &data, regs))
348 			cpu_pmu->disable(event);
349 	}
350 
351 	/*
352 	 * Handle the pending perf events.
353 	 *
354 	 * Note: this call *must* be run with interrupts disabled. For
355 	 * platforms that can have the PMU interrupts raised as an NMI, this
356 	 * will not work.
357 	 */
358 	irq_work_run();
359 
360 	return IRQ_HANDLED;
361 }
362 
363 static void armv6pmu_start(struct arm_pmu *cpu_pmu)
364 {
365 	unsigned long flags, val;
366 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
367 
368 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
369 	val = armv6_pmcr_read();
370 	val |= ARMV6_PMCR_ENABLE;
371 	armv6_pmcr_write(val);
372 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
373 }
374 
375 static void armv6pmu_stop(struct arm_pmu *cpu_pmu)
376 {
377 	unsigned long flags, val;
378 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
379 
380 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
381 	val = armv6_pmcr_read();
382 	val &= ~ARMV6_PMCR_ENABLE;
383 	armv6_pmcr_write(val);
384 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
385 }
386 
387 static int
388 armv6pmu_get_event_idx(struct pmu_hw_events *cpuc,
389 				struct perf_event *event)
390 {
391 	struct hw_perf_event *hwc = &event->hw;
392 	/* Always place a cycle counter into the cycle counter. */
393 	if (ARMV6_PERFCTR_CPU_CYCLES == hwc->config_base) {
394 		if (test_and_set_bit(ARMV6_CYCLE_COUNTER, cpuc->used_mask))
395 			return -EAGAIN;
396 
397 		return ARMV6_CYCLE_COUNTER;
398 	} else {
399 		/*
400 		 * For anything other than a cycle counter, try and use
401 		 * counter0 and counter1.
402 		 */
403 		if (!test_and_set_bit(ARMV6_COUNTER1, cpuc->used_mask))
404 			return ARMV6_COUNTER1;
405 
406 		if (!test_and_set_bit(ARMV6_COUNTER0, cpuc->used_mask))
407 			return ARMV6_COUNTER0;
408 
409 		/* The counters are all in use. */
410 		return -EAGAIN;
411 	}
412 }
413 
414 static void armv6pmu_clear_event_idx(struct pmu_hw_events *cpuc,
415 				     struct perf_event *event)
416 {
417 	clear_bit(event->hw.idx, cpuc->used_mask);
418 }
419 
420 static void armv6pmu_disable_event(struct perf_event *event)
421 {
422 	unsigned long val, mask, evt, flags;
423 	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
424 	struct hw_perf_event *hwc = &event->hw;
425 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
426 	int idx = hwc->idx;
427 
428 	if (ARMV6_CYCLE_COUNTER == idx) {
429 		mask	= ARMV6_PMCR_CCOUNT_IEN;
430 		evt	= 0;
431 	} else if (ARMV6_COUNTER0 == idx) {
432 		mask	= ARMV6_PMCR_COUNT0_IEN | ARMV6_PMCR_EVT_COUNT0_MASK;
433 		evt	= ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT0_SHIFT;
434 	} else if (ARMV6_COUNTER1 == idx) {
435 		mask	= ARMV6_PMCR_COUNT1_IEN | ARMV6_PMCR_EVT_COUNT1_MASK;
436 		evt	= ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT1_SHIFT;
437 	} else {
438 		WARN_ONCE(1, "invalid counter number (%d)\n", idx);
439 		return;
440 	}
441 
442 	/*
443 	 * Mask out the current event and set the counter to count the number
444 	 * of ETM bus signal assertion cycles. The external reporting should
445 	 * be disabled and so this should never increment.
446 	 */
447 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
448 	val = armv6_pmcr_read();
449 	val &= ~mask;
450 	val |= evt;
451 	armv6_pmcr_write(val);
452 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
453 }
454 
455 static void armv6mpcore_pmu_disable_event(struct perf_event *event)
456 {
457 	unsigned long val, mask, flags, evt = 0;
458 	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
459 	struct hw_perf_event *hwc = &event->hw;
460 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
461 	int idx = hwc->idx;
462 
463 	if (ARMV6_CYCLE_COUNTER == idx) {
464 		mask	= ARMV6_PMCR_CCOUNT_IEN;
465 	} else if (ARMV6_COUNTER0 == idx) {
466 		mask	= ARMV6_PMCR_COUNT0_IEN;
467 	} else if (ARMV6_COUNTER1 == idx) {
468 		mask	= ARMV6_PMCR_COUNT1_IEN;
469 	} else {
470 		WARN_ONCE(1, "invalid counter number (%d)\n", idx);
471 		return;
472 	}
473 
474 	/*
475 	 * Unlike UP ARMv6, we don't have a way of stopping the counters. We
476 	 * simply disable the interrupt reporting.
477 	 */
478 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
479 	val = armv6_pmcr_read();
480 	val &= ~mask;
481 	val |= evt;
482 	armv6_pmcr_write(val);
483 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
484 }
485 
486 static int armv6_map_event(struct perf_event *event)
487 {
488 	return armpmu_map_event(event, &armv6_perf_map,
489 				&armv6_perf_cache_map, 0xFF);
490 }
491 
492 static void armv6pmu_init(struct arm_pmu *cpu_pmu)
493 {
494 	cpu_pmu->handle_irq	= armv6pmu_handle_irq;
495 	cpu_pmu->enable		= armv6pmu_enable_event;
496 	cpu_pmu->disable	= armv6pmu_disable_event;
497 	cpu_pmu->read_counter	= armv6pmu_read_counter;
498 	cpu_pmu->write_counter	= armv6pmu_write_counter;
499 	cpu_pmu->get_event_idx	= armv6pmu_get_event_idx;
500 	cpu_pmu->clear_event_idx = armv6pmu_clear_event_idx;
501 	cpu_pmu->start		= armv6pmu_start;
502 	cpu_pmu->stop		= armv6pmu_stop;
503 	cpu_pmu->map_event	= armv6_map_event;
504 	cpu_pmu->num_events	= 3;
505 }
506 
507 static int armv6_1136_pmu_init(struct arm_pmu *cpu_pmu)
508 {
509 	armv6pmu_init(cpu_pmu);
510 	cpu_pmu->name		= "armv6_1136";
511 	return 0;
512 }
513 
514 static int armv6_1156_pmu_init(struct arm_pmu *cpu_pmu)
515 {
516 	armv6pmu_init(cpu_pmu);
517 	cpu_pmu->name		= "armv6_1156";
518 	return 0;
519 }
520 
521 static int armv6_1176_pmu_init(struct arm_pmu *cpu_pmu)
522 {
523 	armv6pmu_init(cpu_pmu);
524 	cpu_pmu->name		= "armv6_1176";
525 	return 0;
526 }
527 
528 /*
529  * ARMv6mpcore is almost identical to single core ARMv6 with the exception
530  * that some of the events have different enumerations and that there is no
531  * *hack* to stop the programmable counters. To stop the counters we simply
532  * disable the interrupt reporting and update the event. When unthrottling we
533  * reset the period and enable the interrupt reporting.
534  */
535 
536 static int armv6mpcore_map_event(struct perf_event *event)
537 {
538 	return armpmu_map_event(event, &armv6mpcore_perf_map,
539 				&armv6mpcore_perf_cache_map, 0xFF);
540 }
541 
542 static int armv6mpcore_pmu_init(struct arm_pmu *cpu_pmu)
543 {
544 	cpu_pmu->name		= "armv6_11mpcore";
545 	cpu_pmu->handle_irq	= armv6pmu_handle_irq;
546 	cpu_pmu->enable		= armv6pmu_enable_event;
547 	cpu_pmu->disable	= armv6mpcore_pmu_disable_event;
548 	cpu_pmu->read_counter	= armv6pmu_read_counter;
549 	cpu_pmu->write_counter	= armv6pmu_write_counter;
550 	cpu_pmu->get_event_idx	= armv6pmu_get_event_idx;
551 	cpu_pmu->clear_event_idx = armv6pmu_clear_event_idx;
552 	cpu_pmu->start		= armv6pmu_start;
553 	cpu_pmu->stop		= armv6pmu_stop;
554 	cpu_pmu->map_event	= armv6mpcore_map_event;
555 	cpu_pmu->num_events	= 3;
556 
557 	return 0;
558 }
559 
560 static const struct of_device_id armv6_pmu_of_device_ids[] = {
561 	{.compatible = "arm,arm11mpcore-pmu",	.data = armv6mpcore_pmu_init},
562 	{.compatible = "arm,arm1176-pmu",	.data = armv6_1176_pmu_init},
563 	{.compatible = "arm,arm1136-pmu",	.data = armv6_1136_pmu_init},
564 	{ /* sentinel value */ }
565 };
566 
567 static const struct pmu_probe_info armv6_pmu_probe_table[] = {
568 	ARM_PMU_PROBE(ARM_CPU_PART_ARM1136, armv6_1136_pmu_init),
569 	ARM_PMU_PROBE(ARM_CPU_PART_ARM1156, armv6_1156_pmu_init),
570 	ARM_PMU_PROBE(ARM_CPU_PART_ARM1176, armv6_1176_pmu_init),
571 	ARM_PMU_PROBE(ARM_CPU_PART_ARM11MPCORE, armv6mpcore_pmu_init),
572 	{ /* sentinel value */ }
573 };
574 
575 static int armv6_pmu_device_probe(struct platform_device *pdev)
576 {
577 	return arm_pmu_device_probe(pdev, armv6_pmu_of_device_ids,
578 				    armv6_pmu_probe_table);
579 }
580 
581 static struct platform_driver armv6_pmu_driver = {
582 	.driver		= {
583 		.name	= "armv6-pmu",
584 		.of_match_table = armv6_pmu_of_device_ids,
585 	},
586 	.probe		= armv6_pmu_device_probe,
587 };
588 
589 builtin_platform_driver(armv6_pmu_driver);
590 #endif	/* CONFIG_CPU_V6 || CONFIG_CPU_V6K */
591