xref: /openbmc/linux/arch/arm/kernel/perf_event_v6.c (revision 2891f2d5)
1 /*
2  * ARMv6 Performance counter handling code.
3  *
4  * Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles
5  *
6  * ARMv6 has 2 configurable performance counters and a single cycle counter.
7  * They all share a single reset bit but can be written to zero so we can use
8  * that for a reset.
9  *
10  * The counters can't be individually enabled or disabled so when we remove
11  * one event and replace it with another we could get spurious counts from the
12  * wrong event. However, we can take advantage of the fact that the
13  * performance counters can export events to the event bus, and the event bus
14  * itself can be monitored. This requires that we *don't* export the events to
15  * the event bus. The procedure for disabling a configurable counter is:
16  *	- change the counter to count the ETMEXTOUT[0] signal (0x20). This
17  *	  effectively stops the counter from counting.
18  *	- disable the counter's interrupt generation (each counter has it's
19  *	  own interrupt enable bit).
20  * Once stopped, the counter value can be written as 0 to reset.
21  *
22  * To enable a counter:
23  *	- enable the counter's interrupt generation.
24  *	- set the new event type.
25  *
26  * Note: the dedicated cycle counter only counts cycles and can't be
27  * enabled/disabled independently of the others. When we want to disable the
28  * cycle counter, we have to just disable the interrupt reporting and start
29  * ignoring that counter. When re-enabling, we have to reset the value and
30  * enable the interrupt.
31  */
32 
33 #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K)
34 
35 #include <asm/cputype.h>
36 #include <asm/irq_regs.h>
37 
38 #include <linux/of.h>
39 #include <linux/perf/arm_pmu.h>
40 #include <linux/platform_device.h>
41 
42 enum armv6_perf_types {
43 	ARMV6_PERFCTR_ICACHE_MISS	    = 0x0,
44 	ARMV6_PERFCTR_IBUF_STALL	    = 0x1,
45 	ARMV6_PERFCTR_DDEP_STALL	    = 0x2,
46 	ARMV6_PERFCTR_ITLB_MISS		    = 0x3,
47 	ARMV6_PERFCTR_DTLB_MISS		    = 0x4,
48 	ARMV6_PERFCTR_BR_EXEC		    = 0x5,
49 	ARMV6_PERFCTR_BR_MISPREDICT	    = 0x6,
50 	ARMV6_PERFCTR_INSTR_EXEC	    = 0x7,
51 	ARMV6_PERFCTR_DCACHE_HIT	    = 0x9,
52 	ARMV6_PERFCTR_DCACHE_ACCESS	    = 0xA,
53 	ARMV6_PERFCTR_DCACHE_MISS	    = 0xB,
54 	ARMV6_PERFCTR_DCACHE_WBACK	    = 0xC,
55 	ARMV6_PERFCTR_SW_PC_CHANGE	    = 0xD,
56 	ARMV6_PERFCTR_MAIN_TLB_MISS	    = 0xF,
57 	ARMV6_PERFCTR_EXPL_D_ACCESS	    = 0x10,
58 	ARMV6_PERFCTR_LSU_FULL_STALL	    = 0x11,
59 	ARMV6_PERFCTR_WBUF_DRAINED	    = 0x12,
60 	ARMV6_PERFCTR_CPU_CYCLES	    = 0xFF,
61 	ARMV6_PERFCTR_NOP		    = 0x20,
62 };
63 
64 enum armv6_counters {
65 	ARMV6_CYCLE_COUNTER = 0,
66 	ARMV6_COUNTER0,
67 	ARMV6_COUNTER1,
68 };
69 
70 /*
71  * The hardware events that we support. We do support cache operations but
72  * we have harvard caches and no way to combine instruction and data
73  * accesses/misses in hardware.
74  */
75 static const unsigned armv6_perf_map[PERF_COUNT_HW_MAX] = {
76 	PERF_MAP_ALL_UNSUPPORTED,
77 	[PERF_COUNT_HW_CPU_CYCLES]		= ARMV6_PERFCTR_CPU_CYCLES,
78 	[PERF_COUNT_HW_INSTRUCTIONS]		= ARMV6_PERFCTR_INSTR_EXEC,
79 	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= ARMV6_PERFCTR_BR_EXEC,
80 	[PERF_COUNT_HW_BRANCH_MISSES]		= ARMV6_PERFCTR_BR_MISPREDICT,
81 	[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= ARMV6_PERFCTR_IBUF_STALL,
82 	[PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= ARMV6_PERFCTR_LSU_FULL_STALL,
83 };
84 
85 static const unsigned armv6_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
86 					  [PERF_COUNT_HW_CACHE_OP_MAX]
87 					  [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
88 	PERF_CACHE_MAP_ALL_UNSUPPORTED,
89 
90 	/*
91 	 * The performance counters don't differentiate between read and write
92 	 * accesses/misses so this isn't strictly correct, but it's the best we
93 	 * can do. Writes and reads get combined.
94 	 */
95 	[C(L1D)][C(OP_READ)][C(RESULT_ACCESS)]	= ARMV6_PERFCTR_DCACHE_ACCESS,
96 	[C(L1D)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6_PERFCTR_DCACHE_MISS,
97 	[C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)]	= ARMV6_PERFCTR_DCACHE_ACCESS,
98 	[C(L1D)][C(OP_WRITE)][C(RESULT_MISS)]	= ARMV6_PERFCTR_DCACHE_MISS,
99 
100 	[C(L1I)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6_PERFCTR_ICACHE_MISS,
101 
102 	/*
103 	 * The ARM performance counters can count micro DTLB misses, micro ITLB
104 	 * misses and main TLB misses. There isn't an event for TLB misses, so
105 	 * use the micro misses here and if users want the main TLB misses they
106 	 * can use a raw counter.
107 	 */
108 	[C(DTLB)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6_PERFCTR_DTLB_MISS,
109 	[C(DTLB)][C(OP_WRITE)][C(RESULT_MISS)]	= ARMV6_PERFCTR_DTLB_MISS,
110 
111 	[C(ITLB)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6_PERFCTR_ITLB_MISS,
112 	[C(ITLB)][C(OP_WRITE)][C(RESULT_MISS)]	= ARMV6_PERFCTR_ITLB_MISS,
113 };
114 
115 enum armv6mpcore_perf_types {
116 	ARMV6MPCORE_PERFCTR_ICACHE_MISS	    = 0x0,
117 	ARMV6MPCORE_PERFCTR_IBUF_STALL	    = 0x1,
118 	ARMV6MPCORE_PERFCTR_DDEP_STALL	    = 0x2,
119 	ARMV6MPCORE_PERFCTR_ITLB_MISS	    = 0x3,
120 	ARMV6MPCORE_PERFCTR_DTLB_MISS	    = 0x4,
121 	ARMV6MPCORE_PERFCTR_BR_EXEC	    = 0x5,
122 	ARMV6MPCORE_PERFCTR_BR_NOTPREDICT   = 0x6,
123 	ARMV6MPCORE_PERFCTR_BR_MISPREDICT   = 0x7,
124 	ARMV6MPCORE_PERFCTR_INSTR_EXEC	    = 0x8,
125 	ARMV6MPCORE_PERFCTR_DCACHE_RDACCESS = 0xA,
126 	ARMV6MPCORE_PERFCTR_DCACHE_RDMISS   = 0xB,
127 	ARMV6MPCORE_PERFCTR_DCACHE_WRACCESS = 0xC,
128 	ARMV6MPCORE_PERFCTR_DCACHE_WRMISS   = 0xD,
129 	ARMV6MPCORE_PERFCTR_DCACHE_EVICTION = 0xE,
130 	ARMV6MPCORE_PERFCTR_SW_PC_CHANGE    = 0xF,
131 	ARMV6MPCORE_PERFCTR_MAIN_TLB_MISS   = 0x10,
132 	ARMV6MPCORE_PERFCTR_EXPL_MEM_ACCESS = 0x11,
133 	ARMV6MPCORE_PERFCTR_LSU_FULL_STALL  = 0x12,
134 	ARMV6MPCORE_PERFCTR_WBUF_DRAINED    = 0x13,
135 	ARMV6MPCORE_PERFCTR_CPU_CYCLES	    = 0xFF,
136 };
137 
138 /*
139  * The hardware events that we support. We do support cache operations but
140  * we have harvard caches and no way to combine instruction and data
141  * accesses/misses in hardware.
142  */
143 static const unsigned armv6mpcore_perf_map[PERF_COUNT_HW_MAX] = {
144 	PERF_MAP_ALL_UNSUPPORTED,
145 	[PERF_COUNT_HW_CPU_CYCLES]		= ARMV6MPCORE_PERFCTR_CPU_CYCLES,
146 	[PERF_COUNT_HW_INSTRUCTIONS]		= ARMV6MPCORE_PERFCTR_INSTR_EXEC,
147 	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= ARMV6MPCORE_PERFCTR_BR_EXEC,
148 	[PERF_COUNT_HW_BRANCH_MISSES]		= ARMV6MPCORE_PERFCTR_BR_MISPREDICT,
149 	[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= ARMV6MPCORE_PERFCTR_IBUF_STALL,
150 	[PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= ARMV6MPCORE_PERFCTR_LSU_FULL_STALL,
151 };
152 
153 static const unsigned armv6mpcore_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
154 					[PERF_COUNT_HW_CACHE_OP_MAX]
155 					[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
156 	PERF_CACHE_MAP_ALL_UNSUPPORTED,
157 
158 	[C(L1D)][C(OP_READ)][C(RESULT_ACCESS)]	= ARMV6MPCORE_PERFCTR_DCACHE_RDACCESS,
159 	[C(L1D)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_DCACHE_RDMISS,
160 	[C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)]	= ARMV6MPCORE_PERFCTR_DCACHE_WRACCESS,
161 	[C(L1D)][C(OP_WRITE)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_DCACHE_WRMISS,
162 
163 	[C(L1I)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_ICACHE_MISS,
164 
165 	/*
166 	 * The ARM performance counters can count micro DTLB misses, micro ITLB
167 	 * misses and main TLB misses. There isn't an event for TLB misses, so
168 	 * use the micro misses here and if users want the main TLB misses they
169 	 * can use a raw counter.
170 	 */
171 	[C(DTLB)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_DTLB_MISS,
172 	[C(DTLB)][C(OP_WRITE)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_DTLB_MISS,
173 
174 	[C(ITLB)][C(OP_READ)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_ITLB_MISS,
175 	[C(ITLB)][C(OP_WRITE)][C(RESULT_MISS)]	= ARMV6MPCORE_PERFCTR_ITLB_MISS,
176 };
177 
178 static inline unsigned long
179 armv6_pmcr_read(void)
180 {
181 	u32 val;
182 	asm volatile("mrc   p15, 0, %0, c15, c12, 0" : "=r"(val));
183 	return val;
184 }
185 
186 static inline void
187 armv6_pmcr_write(unsigned long val)
188 {
189 	asm volatile("mcr   p15, 0, %0, c15, c12, 0" : : "r"(val));
190 }
191 
192 #define ARMV6_PMCR_ENABLE		(1 << 0)
193 #define ARMV6_PMCR_CTR01_RESET		(1 << 1)
194 #define ARMV6_PMCR_CCOUNT_RESET		(1 << 2)
195 #define ARMV6_PMCR_CCOUNT_DIV		(1 << 3)
196 #define ARMV6_PMCR_COUNT0_IEN		(1 << 4)
197 #define ARMV6_PMCR_COUNT1_IEN		(1 << 5)
198 #define ARMV6_PMCR_CCOUNT_IEN		(1 << 6)
199 #define ARMV6_PMCR_COUNT0_OVERFLOW	(1 << 8)
200 #define ARMV6_PMCR_COUNT1_OVERFLOW	(1 << 9)
201 #define ARMV6_PMCR_CCOUNT_OVERFLOW	(1 << 10)
202 #define ARMV6_PMCR_EVT_COUNT0_SHIFT	20
203 #define ARMV6_PMCR_EVT_COUNT0_MASK	(0xFF << ARMV6_PMCR_EVT_COUNT0_SHIFT)
204 #define ARMV6_PMCR_EVT_COUNT1_SHIFT	12
205 #define ARMV6_PMCR_EVT_COUNT1_MASK	(0xFF << ARMV6_PMCR_EVT_COUNT1_SHIFT)
206 
207 #define ARMV6_PMCR_OVERFLOWED_MASK \
208 	(ARMV6_PMCR_COUNT0_OVERFLOW | ARMV6_PMCR_COUNT1_OVERFLOW | \
209 	 ARMV6_PMCR_CCOUNT_OVERFLOW)
210 
211 static inline int
212 armv6_pmcr_has_overflowed(unsigned long pmcr)
213 {
214 	return pmcr & ARMV6_PMCR_OVERFLOWED_MASK;
215 }
216 
217 static inline int
218 armv6_pmcr_counter_has_overflowed(unsigned long pmcr,
219 				  enum armv6_counters counter)
220 {
221 	int ret = 0;
222 
223 	if (ARMV6_CYCLE_COUNTER == counter)
224 		ret = pmcr & ARMV6_PMCR_CCOUNT_OVERFLOW;
225 	else if (ARMV6_COUNTER0 == counter)
226 		ret = pmcr & ARMV6_PMCR_COUNT0_OVERFLOW;
227 	else if (ARMV6_COUNTER1 == counter)
228 		ret = pmcr & ARMV6_PMCR_COUNT1_OVERFLOW;
229 	else
230 		WARN_ONCE(1, "invalid counter number (%d)\n", counter);
231 
232 	return ret;
233 }
234 
235 static inline u32 armv6pmu_read_counter(struct perf_event *event)
236 {
237 	struct hw_perf_event *hwc = &event->hw;
238 	int counter = hwc->idx;
239 	unsigned long value = 0;
240 
241 	if (ARMV6_CYCLE_COUNTER == counter)
242 		asm volatile("mrc   p15, 0, %0, c15, c12, 1" : "=r"(value));
243 	else if (ARMV6_COUNTER0 == counter)
244 		asm volatile("mrc   p15, 0, %0, c15, c12, 2" : "=r"(value));
245 	else if (ARMV6_COUNTER1 == counter)
246 		asm volatile("mrc   p15, 0, %0, c15, c12, 3" : "=r"(value));
247 	else
248 		WARN_ONCE(1, "invalid counter number (%d)\n", counter);
249 
250 	return value;
251 }
252 
253 static inline void armv6pmu_write_counter(struct perf_event *event, u32 value)
254 {
255 	struct hw_perf_event *hwc = &event->hw;
256 	int counter = hwc->idx;
257 
258 	if (ARMV6_CYCLE_COUNTER == counter)
259 		asm volatile("mcr   p15, 0, %0, c15, c12, 1" : : "r"(value));
260 	else if (ARMV6_COUNTER0 == counter)
261 		asm volatile("mcr   p15, 0, %0, c15, c12, 2" : : "r"(value));
262 	else if (ARMV6_COUNTER1 == counter)
263 		asm volatile("mcr   p15, 0, %0, c15, c12, 3" : : "r"(value));
264 	else
265 		WARN_ONCE(1, "invalid counter number (%d)\n", counter);
266 }
267 
268 static void armv6pmu_enable_event(struct perf_event *event)
269 {
270 	unsigned long val, mask, evt, flags;
271 	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
272 	struct hw_perf_event *hwc = &event->hw;
273 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
274 	int idx = hwc->idx;
275 
276 	if (ARMV6_CYCLE_COUNTER == idx) {
277 		mask	= 0;
278 		evt	= ARMV6_PMCR_CCOUNT_IEN;
279 	} else if (ARMV6_COUNTER0 == idx) {
280 		mask	= ARMV6_PMCR_EVT_COUNT0_MASK;
281 		evt	= (hwc->config_base << ARMV6_PMCR_EVT_COUNT0_SHIFT) |
282 			  ARMV6_PMCR_COUNT0_IEN;
283 	} else if (ARMV6_COUNTER1 == idx) {
284 		mask	= ARMV6_PMCR_EVT_COUNT1_MASK;
285 		evt	= (hwc->config_base << ARMV6_PMCR_EVT_COUNT1_SHIFT) |
286 			  ARMV6_PMCR_COUNT1_IEN;
287 	} else {
288 		WARN_ONCE(1, "invalid counter number (%d)\n", idx);
289 		return;
290 	}
291 
292 	/*
293 	 * Mask out the current event and set the counter to count the event
294 	 * that we're interested in.
295 	 */
296 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
297 	val = armv6_pmcr_read();
298 	val &= ~mask;
299 	val |= evt;
300 	armv6_pmcr_write(val);
301 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
302 }
303 
304 static irqreturn_t
305 armv6pmu_handle_irq(int irq_num,
306 		    void *dev)
307 {
308 	unsigned long pmcr = armv6_pmcr_read();
309 	struct perf_sample_data data;
310 	struct arm_pmu *cpu_pmu = (struct arm_pmu *)dev;
311 	struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
312 	struct pt_regs *regs;
313 	int idx;
314 
315 	if (!armv6_pmcr_has_overflowed(pmcr))
316 		return IRQ_NONE;
317 
318 	regs = get_irq_regs();
319 
320 	/*
321 	 * The interrupts are cleared by writing the overflow flags back to
322 	 * the control register. All of the other bits don't have any effect
323 	 * if they are rewritten, so write the whole value back.
324 	 */
325 	armv6_pmcr_write(pmcr);
326 
327 	for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
328 		struct perf_event *event = cpuc->events[idx];
329 		struct hw_perf_event *hwc;
330 
331 		/* Ignore if we don't have an event. */
332 		if (!event)
333 			continue;
334 
335 		/*
336 		 * We have a single interrupt for all counters. Check that
337 		 * each counter has overflowed before we process it.
338 		 */
339 		if (!armv6_pmcr_counter_has_overflowed(pmcr, idx))
340 			continue;
341 
342 		hwc = &event->hw;
343 		armpmu_event_update(event);
344 		perf_sample_data_init(&data, 0, hwc->last_period);
345 		if (!armpmu_event_set_period(event))
346 			continue;
347 
348 		if (perf_event_overflow(event, &data, regs))
349 			cpu_pmu->disable(event);
350 	}
351 
352 	/*
353 	 * Handle the pending perf events.
354 	 *
355 	 * Note: this call *must* be run with interrupts disabled. For
356 	 * platforms that can have the PMU interrupts raised as an NMI, this
357 	 * will not work.
358 	 */
359 	irq_work_run();
360 
361 	return IRQ_HANDLED;
362 }
363 
364 static void armv6pmu_start(struct arm_pmu *cpu_pmu)
365 {
366 	unsigned long flags, val;
367 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
368 
369 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
370 	val = armv6_pmcr_read();
371 	val |= ARMV6_PMCR_ENABLE;
372 	armv6_pmcr_write(val);
373 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
374 }
375 
376 static void armv6pmu_stop(struct arm_pmu *cpu_pmu)
377 {
378 	unsigned long flags, val;
379 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
380 
381 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
382 	val = armv6_pmcr_read();
383 	val &= ~ARMV6_PMCR_ENABLE;
384 	armv6_pmcr_write(val);
385 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
386 }
387 
388 static int
389 armv6pmu_get_event_idx(struct pmu_hw_events *cpuc,
390 				struct perf_event *event)
391 {
392 	struct hw_perf_event *hwc = &event->hw;
393 	/* Always place a cycle counter into the cycle counter. */
394 	if (ARMV6_PERFCTR_CPU_CYCLES == hwc->config_base) {
395 		if (test_and_set_bit(ARMV6_CYCLE_COUNTER, cpuc->used_mask))
396 			return -EAGAIN;
397 
398 		return ARMV6_CYCLE_COUNTER;
399 	} else {
400 		/*
401 		 * For anything other than a cycle counter, try and use
402 		 * counter0 and counter1.
403 		 */
404 		if (!test_and_set_bit(ARMV6_COUNTER1, cpuc->used_mask))
405 			return ARMV6_COUNTER1;
406 
407 		if (!test_and_set_bit(ARMV6_COUNTER0, cpuc->used_mask))
408 			return ARMV6_COUNTER0;
409 
410 		/* The counters are all in use. */
411 		return -EAGAIN;
412 	}
413 }
414 
415 static void armv6pmu_disable_event(struct perf_event *event)
416 {
417 	unsigned long val, mask, evt, flags;
418 	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
419 	struct hw_perf_event *hwc = &event->hw;
420 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
421 	int idx = hwc->idx;
422 
423 	if (ARMV6_CYCLE_COUNTER == idx) {
424 		mask	= ARMV6_PMCR_CCOUNT_IEN;
425 		evt	= 0;
426 	} else if (ARMV6_COUNTER0 == idx) {
427 		mask	= ARMV6_PMCR_COUNT0_IEN | ARMV6_PMCR_EVT_COUNT0_MASK;
428 		evt	= ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT0_SHIFT;
429 	} else if (ARMV6_COUNTER1 == idx) {
430 		mask	= ARMV6_PMCR_COUNT1_IEN | ARMV6_PMCR_EVT_COUNT1_MASK;
431 		evt	= ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT1_SHIFT;
432 	} else {
433 		WARN_ONCE(1, "invalid counter number (%d)\n", idx);
434 		return;
435 	}
436 
437 	/*
438 	 * Mask out the current event and set the counter to count the number
439 	 * of ETM bus signal assertion cycles. The external reporting should
440 	 * be disabled and so this should never increment.
441 	 */
442 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
443 	val = armv6_pmcr_read();
444 	val &= ~mask;
445 	val |= evt;
446 	armv6_pmcr_write(val);
447 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
448 }
449 
450 static void armv6mpcore_pmu_disable_event(struct perf_event *event)
451 {
452 	unsigned long val, mask, flags, evt = 0;
453 	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
454 	struct hw_perf_event *hwc = &event->hw;
455 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
456 	int idx = hwc->idx;
457 
458 	if (ARMV6_CYCLE_COUNTER == idx) {
459 		mask	= ARMV6_PMCR_CCOUNT_IEN;
460 	} else if (ARMV6_COUNTER0 == idx) {
461 		mask	= ARMV6_PMCR_COUNT0_IEN;
462 	} else if (ARMV6_COUNTER1 == idx) {
463 		mask	= ARMV6_PMCR_COUNT1_IEN;
464 	} else {
465 		WARN_ONCE(1, "invalid counter number (%d)\n", idx);
466 		return;
467 	}
468 
469 	/*
470 	 * Unlike UP ARMv6, we don't have a way of stopping the counters. We
471 	 * simply disable the interrupt reporting.
472 	 */
473 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
474 	val = armv6_pmcr_read();
475 	val &= ~mask;
476 	val |= evt;
477 	armv6_pmcr_write(val);
478 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
479 }
480 
481 static int armv6_map_event(struct perf_event *event)
482 {
483 	return armpmu_map_event(event, &armv6_perf_map,
484 				&armv6_perf_cache_map, 0xFF);
485 }
486 
487 static void armv6pmu_init(struct arm_pmu *cpu_pmu)
488 {
489 	cpu_pmu->handle_irq	= armv6pmu_handle_irq;
490 	cpu_pmu->enable		= armv6pmu_enable_event;
491 	cpu_pmu->disable	= armv6pmu_disable_event;
492 	cpu_pmu->read_counter	= armv6pmu_read_counter;
493 	cpu_pmu->write_counter	= armv6pmu_write_counter;
494 	cpu_pmu->get_event_idx	= armv6pmu_get_event_idx;
495 	cpu_pmu->start		= armv6pmu_start;
496 	cpu_pmu->stop		= armv6pmu_stop;
497 	cpu_pmu->map_event	= armv6_map_event;
498 	cpu_pmu->num_events	= 3;
499 	cpu_pmu->max_period	= (1LLU << 32) - 1;
500 }
501 
502 static int armv6_1136_pmu_init(struct arm_pmu *cpu_pmu)
503 {
504 	armv6pmu_init(cpu_pmu);
505 	cpu_pmu->name		= "armv6_1136";
506 	return 0;
507 }
508 
509 static int armv6_1156_pmu_init(struct arm_pmu *cpu_pmu)
510 {
511 	armv6pmu_init(cpu_pmu);
512 	cpu_pmu->name		= "armv6_1156";
513 	return 0;
514 }
515 
516 static int armv6_1176_pmu_init(struct arm_pmu *cpu_pmu)
517 {
518 	armv6pmu_init(cpu_pmu);
519 	cpu_pmu->name		= "armv6_1176";
520 	return 0;
521 }
522 
523 /*
524  * ARMv6mpcore is almost identical to single core ARMv6 with the exception
525  * that some of the events have different enumerations and that there is no
526  * *hack* to stop the programmable counters. To stop the counters we simply
527  * disable the interrupt reporting and update the event. When unthrottling we
528  * reset the period and enable the interrupt reporting.
529  */
530 
531 static int armv6mpcore_map_event(struct perf_event *event)
532 {
533 	return armpmu_map_event(event, &armv6mpcore_perf_map,
534 				&armv6mpcore_perf_cache_map, 0xFF);
535 }
536 
537 static int armv6mpcore_pmu_init(struct arm_pmu *cpu_pmu)
538 {
539 	cpu_pmu->name		= "armv6_11mpcore";
540 	cpu_pmu->handle_irq	= armv6pmu_handle_irq;
541 	cpu_pmu->enable		= armv6pmu_enable_event;
542 	cpu_pmu->disable	= armv6mpcore_pmu_disable_event;
543 	cpu_pmu->read_counter	= armv6pmu_read_counter;
544 	cpu_pmu->write_counter	= armv6pmu_write_counter;
545 	cpu_pmu->get_event_idx	= armv6pmu_get_event_idx;
546 	cpu_pmu->start		= armv6pmu_start;
547 	cpu_pmu->stop		= armv6pmu_stop;
548 	cpu_pmu->map_event	= armv6mpcore_map_event;
549 	cpu_pmu->num_events	= 3;
550 	cpu_pmu->max_period	= (1LLU << 32) - 1;
551 
552 	return 0;
553 }
554 
555 static struct of_device_id armv6_pmu_of_device_ids[] = {
556 	{.compatible = "arm,arm11mpcore-pmu",	.data = armv6mpcore_pmu_init},
557 	{.compatible = "arm,arm1176-pmu",	.data = armv6_1176_pmu_init},
558 	{.compatible = "arm,arm1136-pmu",	.data = armv6_1136_pmu_init},
559 	{ /* sentinel value */ }
560 };
561 
562 static const struct pmu_probe_info armv6_pmu_probe_table[] = {
563 	ARM_PMU_PROBE(ARM_CPU_PART_ARM1136, armv6_1136_pmu_init),
564 	ARM_PMU_PROBE(ARM_CPU_PART_ARM1156, armv6_1156_pmu_init),
565 	ARM_PMU_PROBE(ARM_CPU_PART_ARM1176, armv6_1176_pmu_init),
566 	ARM_PMU_PROBE(ARM_CPU_PART_ARM11MPCORE, armv6mpcore_pmu_init),
567 	{ /* sentinel value */ }
568 };
569 
570 static int armv6_pmu_device_probe(struct platform_device *pdev)
571 {
572 	return arm_pmu_device_probe(pdev, armv6_pmu_of_device_ids,
573 				    armv6_pmu_probe_table);
574 }
575 
576 static struct platform_driver armv6_pmu_driver = {
577 	.driver		= {
578 		.name	= "armv6-pmu",
579 		.of_match_table = armv6_pmu_of_device_ids,
580 	},
581 	.probe		= armv6_pmu_device_probe,
582 };
583 
584 builtin_platform_driver(armv6_pmu_driver);
585 #endif	/* CONFIG_CPU_V6 || CONFIG_CPU_V6K */
586