xref: /openbmc/linux/arch/arm/kernel/perf_event_v6.c (revision 160b8e75)
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 u32 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, u32 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(int irq_num,
307 		    void *dev)
308 {
309 	unsigned long pmcr = armv6_pmcr_read();
310 	struct perf_sample_data data;
311 	struct arm_pmu *cpu_pmu = (struct arm_pmu *)dev;
312 	struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
313 	struct pt_regs *regs;
314 	int idx;
315 
316 	if (!armv6_pmcr_has_overflowed(pmcr))
317 		return IRQ_NONE;
318 
319 	regs = get_irq_regs();
320 
321 	/*
322 	 * The interrupts are cleared by writing the overflow flags back to
323 	 * the control register. All of the other bits don't have any effect
324 	 * if they are rewritten, so write the whole value back.
325 	 */
326 	armv6_pmcr_write(pmcr);
327 
328 	for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
329 		struct perf_event *event = cpuc->events[idx];
330 		struct hw_perf_event *hwc;
331 
332 		/* Ignore if we don't have an event. */
333 		if (!event)
334 			continue;
335 
336 		/*
337 		 * We have a single interrupt for all counters. Check that
338 		 * each counter has overflowed before we process it.
339 		 */
340 		if (!armv6_pmcr_counter_has_overflowed(pmcr, idx))
341 			continue;
342 
343 		hwc = &event->hw;
344 		armpmu_event_update(event);
345 		perf_sample_data_init(&data, 0, hwc->last_period);
346 		if (!armpmu_event_set_period(event))
347 			continue;
348 
349 		if (perf_event_overflow(event, &data, regs))
350 			cpu_pmu->disable(event);
351 	}
352 
353 	/*
354 	 * Handle the pending perf events.
355 	 *
356 	 * Note: this call *must* be run with interrupts disabled. For
357 	 * platforms that can have the PMU interrupts raised as an NMI, this
358 	 * will not work.
359 	 */
360 	irq_work_run();
361 
362 	return IRQ_HANDLED;
363 }
364 
365 static void armv6pmu_start(struct arm_pmu *cpu_pmu)
366 {
367 	unsigned long flags, val;
368 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
369 
370 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
371 	val = armv6_pmcr_read();
372 	val |= ARMV6_PMCR_ENABLE;
373 	armv6_pmcr_write(val);
374 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
375 }
376 
377 static void armv6pmu_stop(struct arm_pmu *cpu_pmu)
378 {
379 	unsigned long flags, val;
380 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
381 
382 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
383 	val = armv6_pmcr_read();
384 	val &= ~ARMV6_PMCR_ENABLE;
385 	armv6_pmcr_write(val);
386 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
387 }
388 
389 static int
390 armv6pmu_get_event_idx(struct pmu_hw_events *cpuc,
391 				struct perf_event *event)
392 {
393 	struct hw_perf_event *hwc = &event->hw;
394 	/* Always place a cycle counter into the cycle counter. */
395 	if (ARMV6_PERFCTR_CPU_CYCLES == hwc->config_base) {
396 		if (test_and_set_bit(ARMV6_CYCLE_COUNTER, cpuc->used_mask))
397 			return -EAGAIN;
398 
399 		return ARMV6_CYCLE_COUNTER;
400 	} else {
401 		/*
402 		 * For anything other than a cycle counter, try and use
403 		 * counter0 and counter1.
404 		 */
405 		if (!test_and_set_bit(ARMV6_COUNTER1, cpuc->used_mask))
406 			return ARMV6_COUNTER1;
407 
408 		if (!test_and_set_bit(ARMV6_COUNTER0, cpuc->used_mask))
409 			return ARMV6_COUNTER0;
410 
411 		/* The counters are all in use. */
412 		return -EAGAIN;
413 	}
414 }
415 
416 static void armv6pmu_disable_event(struct perf_event *event)
417 {
418 	unsigned long val, mask, evt, flags;
419 	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
420 	struct hw_perf_event *hwc = &event->hw;
421 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
422 	int idx = hwc->idx;
423 
424 	if (ARMV6_CYCLE_COUNTER == idx) {
425 		mask	= ARMV6_PMCR_CCOUNT_IEN;
426 		evt	= 0;
427 	} else if (ARMV6_COUNTER0 == idx) {
428 		mask	= ARMV6_PMCR_COUNT0_IEN | ARMV6_PMCR_EVT_COUNT0_MASK;
429 		evt	= ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT0_SHIFT;
430 	} else if (ARMV6_COUNTER1 == idx) {
431 		mask	= ARMV6_PMCR_COUNT1_IEN | ARMV6_PMCR_EVT_COUNT1_MASK;
432 		evt	= ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT1_SHIFT;
433 	} else {
434 		WARN_ONCE(1, "invalid counter number (%d)\n", idx);
435 		return;
436 	}
437 
438 	/*
439 	 * Mask out the current event and set the counter to count the number
440 	 * of ETM bus signal assertion cycles. The external reporting should
441 	 * be disabled and so this should never increment.
442 	 */
443 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
444 	val = armv6_pmcr_read();
445 	val &= ~mask;
446 	val |= evt;
447 	armv6_pmcr_write(val);
448 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
449 }
450 
451 static void armv6mpcore_pmu_disable_event(struct perf_event *event)
452 {
453 	unsigned long val, mask, flags, evt = 0;
454 	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
455 	struct hw_perf_event *hwc = &event->hw;
456 	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
457 	int idx = hwc->idx;
458 
459 	if (ARMV6_CYCLE_COUNTER == idx) {
460 		mask	= ARMV6_PMCR_CCOUNT_IEN;
461 	} else if (ARMV6_COUNTER0 == idx) {
462 		mask	= ARMV6_PMCR_COUNT0_IEN;
463 	} else if (ARMV6_COUNTER1 == idx) {
464 		mask	= ARMV6_PMCR_COUNT1_IEN;
465 	} else {
466 		WARN_ONCE(1, "invalid counter number (%d)\n", idx);
467 		return;
468 	}
469 
470 	/*
471 	 * Unlike UP ARMv6, we don't have a way of stopping the counters. We
472 	 * simply disable the interrupt reporting.
473 	 */
474 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
475 	val = armv6_pmcr_read();
476 	val &= ~mask;
477 	val |= evt;
478 	armv6_pmcr_write(val);
479 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
480 }
481 
482 static int armv6_map_event(struct perf_event *event)
483 {
484 	return armpmu_map_event(event, &armv6_perf_map,
485 				&armv6_perf_cache_map, 0xFF);
486 }
487 
488 static void armv6pmu_init(struct arm_pmu *cpu_pmu)
489 {
490 	cpu_pmu->handle_irq	= armv6pmu_handle_irq;
491 	cpu_pmu->enable		= armv6pmu_enable_event;
492 	cpu_pmu->disable	= armv6pmu_disable_event;
493 	cpu_pmu->read_counter	= armv6pmu_read_counter;
494 	cpu_pmu->write_counter	= armv6pmu_write_counter;
495 	cpu_pmu->get_event_idx	= armv6pmu_get_event_idx;
496 	cpu_pmu->start		= armv6pmu_start;
497 	cpu_pmu->stop		= armv6pmu_stop;
498 	cpu_pmu->map_event	= armv6_map_event;
499 	cpu_pmu->num_events	= 3;
500 	cpu_pmu->max_period	= (1LLU << 32) - 1;
501 }
502 
503 static int armv6_1136_pmu_init(struct arm_pmu *cpu_pmu)
504 {
505 	armv6pmu_init(cpu_pmu);
506 	cpu_pmu->name		= "armv6_1136";
507 	return 0;
508 }
509 
510 static int armv6_1156_pmu_init(struct arm_pmu *cpu_pmu)
511 {
512 	armv6pmu_init(cpu_pmu);
513 	cpu_pmu->name		= "armv6_1156";
514 	return 0;
515 }
516 
517 static int armv6_1176_pmu_init(struct arm_pmu *cpu_pmu)
518 {
519 	armv6pmu_init(cpu_pmu);
520 	cpu_pmu->name		= "armv6_1176";
521 	return 0;
522 }
523 
524 /*
525  * ARMv6mpcore is almost identical to single core ARMv6 with the exception
526  * that some of the events have different enumerations and that there is no
527  * *hack* to stop the programmable counters. To stop the counters we simply
528  * disable the interrupt reporting and update the event. When unthrottling we
529  * reset the period and enable the interrupt reporting.
530  */
531 
532 static int armv6mpcore_map_event(struct perf_event *event)
533 {
534 	return armpmu_map_event(event, &armv6mpcore_perf_map,
535 				&armv6mpcore_perf_cache_map, 0xFF);
536 }
537 
538 static int armv6mpcore_pmu_init(struct arm_pmu *cpu_pmu)
539 {
540 	cpu_pmu->name		= "armv6_11mpcore";
541 	cpu_pmu->handle_irq	= armv6pmu_handle_irq;
542 	cpu_pmu->enable		= armv6pmu_enable_event;
543 	cpu_pmu->disable	= armv6mpcore_pmu_disable_event;
544 	cpu_pmu->read_counter	= armv6pmu_read_counter;
545 	cpu_pmu->write_counter	= armv6pmu_write_counter;
546 	cpu_pmu->get_event_idx	= armv6pmu_get_event_idx;
547 	cpu_pmu->start		= armv6pmu_start;
548 	cpu_pmu->stop		= armv6pmu_stop;
549 	cpu_pmu->map_event	= armv6mpcore_map_event;
550 	cpu_pmu->num_events	= 3;
551 	cpu_pmu->max_period	= (1LLU << 32) - 1;
552 
553 	return 0;
554 }
555 
556 static const struct of_device_id armv6_pmu_of_device_ids[] = {
557 	{.compatible = "arm,arm11mpcore-pmu",	.data = armv6mpcore_pmu_init},
558 	{.compatible = "arm,arm1176-pmu",	.data = armv6_1176_pmu_init},
559 	{.compatible = "arm,arm1136-pmu",	.data = armv6_1136_pmu_init},
560 	{ /* sentinel value */ }
561 };
562 
563 static const struct pmu_probe_info armv6_pmu_probe_table[] = {
564 	ARM_PMU_PROBE(ARM_CPU_PART_ARM1136, armv6_1136_pmu_init),
565 	ARM_PMU_PROBE(ARM_CPU_PART_ARM1156, armv6_1156_pmu_init),
566 	ARM_PMU_PROBE(ARM_CPU_PART_ARM1176, armv6_1176_pmu_init),
567 	ARM_PMU_PROBE(ARM_CPU_PART_ARM11MPCORE, armv6mpcore_pmu_init),
568 	{ /* sentinel value */ }
569 };
570 
571 static int armv6_pmu_device_probe(struct platform_device *pdev)
572 {
573 	return arm_pmu_device_probe(pdev, armv6_pmu_of_device_ids,
574 				    armv6_pmu_probe_table);
575 }
576 
577 static struct platform_driver armv6_pmu_driver = {
578 	.driver		= {
579 		.name	= "armv6-pmu",
580 		.of_match_table = armv6_pmu_of_device_ids,
581 	},
582 	.probe		= armv6_pmu_device_probe,
583 };
584 
585 builtin_platform_driver(armv6_pmu_driver);
586 #endif	/* CONFIG_CPU_V6 || CONFIG_CPU_V6K */
587