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linux/arch/arm/kernel/perf_event_v6.c
Will Deacon a737823d37 ARM: 6835/1: perf: ensure overflows aren't missed due to IRQ latency 
If a counter overflows during a perf stat profiling run it may overtake
the last known value of the counter:

    0        prev     new                0xffffffff
    |----------|-------|----------------------|

In this case, the number of events that have occurred is
(0xffffffff - prev) + new. Unfortunately, the event update code will
not realise an overflow has occurred and will instead report the event
delta as (new - prev) which may be considerably smaller than the real
count.

This patch adds an extra argument to armpmu_event_update which indicates
whether or not an overflow has occurred. If an overflow has occurred
then we use the maximum period of the counter to calculate the elapsed
events.

Acked-by: Jamie Iles <jamie@jamieiles.com>
Reported-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-03-26 10:06:09 +00:00

673 lines
19 KiB
C
Raw Blame History

/*
* ARMv6 Performance counter handling code.
*
* Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles
*
* ARMv6 has 2 configurable performance counters and a single cycle counter.
* They all share a single reset bit but can be written to zero so we can use
* that for a reset.
*
* The counters can't be individually enabled or disabled so when we remove
* one event and replace it with another we could get spurious counts from the
* wrong event. However, we can take advantage of the fact that the
* performance counters can export events to the event bus, and the event bus
* itself can be monitored. This requires that we *don't* export the events to
* the event bus. The procedure for disabling a configurable counter is:
* - change the counter to count the ETMEXTOUT[0] signal (0x20). This
* effectively stops the counter from counting.
* - disable the counter's interrupt generation (each counter has it's
* own interrupt enable bit).
* Once stopped, the counter value can be written as 0 to reset.
*
* To enable a counter:
* - enable the counter's interrupt generation.
* - set the new event type.
*
* Note: the dedicated cycle counter only counts cycles and can't be
* enabled/disabled independently of the others. When we want to disable the
* cycle counter, we have to just disable the interrupt reporting and start
* ignoring that counter. When re-enabling, we have to reset the value and
* enable the interrupt.
*/
#if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K)
enum armv6_perf_types {
ARMV6_PERFCTR_ICACHE_MISS = 0x0,
ARMV6_PERFCTR_IBUF_STALL = 0x1,
ARMV6_PERFCTR_DDEP_STALL = 0x2,
ARMV6_PERFCTR_ITLB_MISS = 0x3,
ARMV6_PERFCTR_DTLB_MISS = 0x4,
ARMV6_PERFCTR_BR_EXEC = 0x5,
ARMV6_PERFCTR_BR_MISPREDICT = 0x6,
ARMV6_PERFCTR_INSTR_EXEC = 0x7,
ARMV6_PERFCTR_DCACHE_HIT = 0x9,
ARMV6_PERFCTR_DCACHE_ACCESS = 0xA,
ARMV6_PERFCTR_DCACHE_MISS = 0xB,
ARMV6_PERFCTR_DCACHE_WBACK = 0xC,
ARMV6_PERFCTR_SW_PC_CHANGE = 0xD,
ARMV6_PERFCTR_MAIN_TLB_MISS = 0xF,
ARMV6_PERFCTR_EXPL_D_ACCESS = 0x10,
ARMV6_PERFCTR_LSU_FULL_STALL = 0x11,
ARMV6_PERFCTR_WBUF_DRAINED = 0x12,
ARMV6_PERFCTR_CPU_CYCLES = 0xFF,
ARMV6_PERFCTR_NOP = 0x20,
};
enum armv6_counters {
ARMV6_CYCLE_COUNTER = 1,
ARMV6_COUNTER0,
ARMV6_COUNTER1,
};
/*
* The hardware events that we support. We do support cache operations but
* we have harvard caches and no way to combine instruction and data
* accesses/misses in hardware.
*/
static const unsigned armv6_perf_map[PERF_COUNT_HW_MAX] = {
[PERF_COUNT_HW_CPU_CYCLES] = ARMV6_PERFCTR_CPU_CYCLES,
[PERF_COUNT_HW_INSTRUCTIONS] = ARMV6_PERFCTR_INSTR_EXEC,
[PERF_COUNT_HW_CACHE_REFERENCES] = HW_OP_UNSUPPORTED,
[PERF_COUNT_HW_CACHE_MISSES] = HW_OP_UNSUPPORTED,
[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = ARMV6_PERFCTR_BR_EXEC,
[PERF_COUNT_HW_BRANCH_MISSES] = ARMV6_PERFCTR_BR_MISPREDICT,
[PERF_COUNT_HW_BUS_CYCLES] = HW_OP_UNSUPPORTED,
};
static const unsigned armv6_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
[C(L1D)] = {
/*
* The performance counters don't differentiate between read
* and write accesses/misses so this isn't strictly correct,
* but it's the best we can do. Writes and reads get
* combined.
*/
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = ARMV6_PERFCTR_DCACHE_ACCESS,
[C(RESULT_MISS)] = ARMV6_PERFCTR_DCACHE_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = ARMV6_PERFCTR_DCACHE_ACCESS,
[C(RESULT_MISS)] = ARMV6_PERFCTR_DCACHE_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(L1I)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6_PERFCTR_ICACHE_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6_PERFCTR_ICACHE_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(LL)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(DTLB)] = {
/*
* The ARM performance counters can count micro DTLB misses,
* micro ITLB misses and main TLB misses. There isn't an event
* for TLB misses, so use the micro misses here and if users
* want the main TLB misses they can use a raw counter.
*/
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6_PERFCTR_DTLB_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6_PERFCTR_DTLB_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(ITLB)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6_PERFCTR_ITLB_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6_PERFCTR_ITLB_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(BPU)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
};
enum armv6mpcore_perf_types {
ARMV6MPCORE_PERFCTR_ICACHE_MISS = 0x0,
ARMV6MPCORE_PERFCTR_IBUF_STALL = 0x1,
ARMV6MPCORE_PERFCTR_DDEP_STALL = 0x2,
ARMV6MPCORE_PERFCTR_ITLB_MISS = 0x3,
ARMV6MPCORE_PERFCTR_DTLB_MISS = 0x4,
ARMV6MPCORE_PERFCTR_BR_EXEC = 0x5,
ARMV6MPCORE_PERFCTR_BR_NOTPREDICT = 0x6,
ARMV6MPCORE_PERFCTR_BR_MISPREDICT = 0x7,
ARMV6MPCORE_PERFCTR_INSTR_EXEC = 0x8,
ARMV6MPCORE_PERFCTR_DCACHE_RDACCESS = 0xA,
ARMV6MPCORE_PERFCTR_DCACHE_RDMISS = 0xB,
ARMV6MPCORE_PERFCTR_DCACHE_WRACCESS = 0xC,
ARMV6MPCORE_PERFCTR_DCACHE_WRMISS = 0xD,
ARMV6MPCORE_PERFCTR_DCACHE_EVICTION = 0xE,
ARMV6MPCORE_PERFCTR_SW_PC_CHANGE = 0xF,
ARMV6MPCORE_PERFCTR_MAIN_TLB_MISS = 0x10,
ARMV6MPCORE_PERFCTR_EXPL_MEM_ACCESS = 0x11,
ARMV6MPCORE_PERFCTR_LSU_FULL_STALL = 0x12,
ARMV6MPCORE_PERFCTR_WBUF_DRAINED = 0x13,
ARMV6MPCORE_PERFCTR_CPU_CYCLES = 0xFF,
};
/*
* The hardware events that we support. We do support cache operations but
* we have harvard caches and no way to combine instruction and data
* accesses/misses in hardware.
*/
static const unsigned armv6mpcore_perf_map[PERF_COUNT_HW_MAX] = {
[PERF_COUNT_HW_CPU_CYCLES] = ARMV6MPCORE_PERFCTR_CPU_CYCLES,
[PERF_COUNT_HW_INSTRUCTIONS] = ARMV6MPCORE_PERFCTR_INSTR_EXEC,
[PERF_COUNT_HW_CACHE_REFERENCES] = HW_OP_UNSUPPORTED,
[PERF_COUNT_HW_CACHE_MISSES] = HW_OP_UNSUPPORTED,
[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = ARMV6MPCORE_PERFCTR_BR_EXEC,
[PERF_COUNT_HW_BRANCH_MISSES] = ARMV6MPCORE_PERFCTR_BR_MISPREDICT,
[PERF_COUNT_HW_BUS_CYCLES] = HW_OP_UNSUPPORTED,
};
static const unsigned armv6mpcore_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
[C(L1D)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] =
ARMV6MPCORE_PERFCTR_DCACHE_RDACCESS,
[C(RESULT_MISS)] =
ARMV6MPCORE_PERFCTR_DCACHE_RDMISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] =
ARMV6MPCORE_PERFCTR_DCACHE_WRACCESS,
[C(RESULT_MISS)] =
ARMV6MPCORE_PERFCTR_DCACHE_WRMISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(L1I)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ICACHE_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ICACHE_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(LL)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(DTLB)] = {
/*
* The ARM performance counters can count micro DTLB misses,
* micro ITLB misses and main TLB misses. There isn't an event
* for TLB misses, so use the micro misses here and if users
* want the main TLB misses they can use a raw counter.
*/
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_DTLB_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_DTLB_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(ITLB)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ITLB_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ITLB_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(BPU)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
};
static inline unsigned long
armv6_pmcr_read(void)
{
u32 val;
asm volatile("mrc p15, 0, %0, c15, c12, 0" : "=r"(val));
return val;
}
static inline void
armv6_pmcr_write(unsigned long val)
{
asm volatile("mcr p15, 0, %0, c15, c12, 0" : : "r"(val));
}
#define ARMV6_PMCR_ENABLE (1 << 0)
#define ARMV6_PMCR_CTR01_RESET (1 << 1)
#define ARMV6_PMCR_CCOUNT_RESET (1 << 2)
#define ARMV6_PMCR_CCOUNT_DIV (1 << 3)
#define ARMV6_PMCR_COUNT0_IEN (1 << 4)
#define ARMV6_PMCR_COUNT1_IEN (1 << 5)
#define ARMV6_PMCR_CCOUNT_IEN (1 << 6)
#define ARMV6_PMCR_COUNT0_OVERFLOW (1 << 8)
#define ARMV6_PMCR_COUNT1_OVERFLOW (1 << 9)
#define ARMV6_PMCR_CCOUNT_OVERFLOW (1 << 10)
#define ARMV6_PMCR_EVT_COUNT0_SHIFT 20
#define ARMV6_PMCR_EVT_COUNT0_MASK (0xFF << ARMV6_PMCR_EVT_COUNT0_SHIFT)
#define ARMV6_PMCR_EVT_COUNT1_SHIFT 12
#define ARMV6_PMCR_EVT_COUNT1_MASK (0xFF << ARMV6_PMCR_EVT_COUNT1_SHIFT)
#define ARMV6_PMCR_OVERFLOWED_MASK \
(ARMV6_PMCR_COUNT0_OVERFLOW | ARMV6_PMCR_COUNT1_OVERFLOW | \
ARMV6_PMCR_CCOUNT_OVERFLOW)
static inline int
armv6_pmcr_has_overflowed(unsigned long pmcr)
{
return pmcr & ARMV6_PMCR_OVERFLOWED_MASK;
}
static inline int
armv6_pmcr_counter_has_overflowed(unsigned long pmcr,
enum armv6_counters counter)
{
int ret = 0;
if (ARMV6_CYCLE_COUNTER == counter)
ret = pmcr & ARMV6_PMCR_CCOUNT_OVERFLOW;
else if (ARMV6_COUNTER0 == counter)
ret = pmcr & ARMV6_PMCR_COUNT0_OVERFLOW;
else if (ARMV6_COUNTER1 == counter)
ret = pmcr & ARMV6_PMCR_COUNT1_OVERFLOW;
else
WARN_ONCE(1, "invalid counter number (%d)\n", counter);
return ret;
}
static inline u32
armv6pmu_read_counter(int counter)
{
unsigned long value = 0;
if (ARMV6_CYCLE_COUNTER == counter)
asm volatile("mrc p15, 0, %0, c15, c12, 1" : "=r"(value));
else if (ARMV6_COUNTER0 == counter)
asm volatile("mrc p15, 0, %0, c15, c12, 2" : "=r"(value));
else if (ARMV6_COUNTER1 == counter)
asm volatile("mrc p15, 0, %0, c15, c12, 3" : "=r"(value));
else
WARN_ONCE(1, "invalid counter number (%d)\n", counter);
return value;
}
static inline void
armv6pmu_write_counter(int counter,
u32 value)
{
if (ARMV6_CYCLE_COUNTER == counter)
asm volatile("mcr p15, 0, %0, c15, c12, 1" : : "r"(value));
else if (ARMV6_COUNTER0 == counter)
asm volatile("mcr p15, 0, %0, c15, c12, 2" : : "r"(value));
else if (ARMV6_COUNTER1 == counter)
asm volatile("mcr p15, 0, %0, c15, c12, 3" : : "r"(value));
else
WARN_ONCE(1, "invalid counter number (%d)\n", counter);
}
static void
armv6pmu_enable_event(struct hw_perf_event *hwc,
int idx)
{
unsigned long val, mask, evt, flags;
if (ARMV6_CYCLE_COUNTER == idx) {
mask = 0;
evt = ARMV6_PMCR_CCOUNT_IEN;
} else if (ARMV6_COUNTER0 == idx) {
mask = ARMV6_PMCR_EVT_COUNT0_MASK;
evt = (hwc->config_base << ARMV6_PMCR_EVT_COUNT0_SHIFT) |
ARMV6_PMCR_COUNT0_IEN;
} else if (ARMV6_COUNTER1 == idx) {
mask = ARMV6_PMCR_EVT_COUNT1_MASK;
evt = (hwc->config_base << ARMV6_PMCR_EVT_COUNT1_SHIFT) |
ARMV6_PMCR_COUNT1_IEN;
} else {
WARN_ONCE(1, "invalid counter number (%d)\n", idx);
return;
}
/*
* Mask out the current event and set the counter to count the event
* that we're interested in.
*/
raw_spin_lock_irqsave(&pmu_lock, flags);
val = armv6_pmcr_read();
val &= ~mask;
val |= evt;
armv6_pmcr_write(val);
raw_spin_unlock_irqrestore(&pmu_lock, flags);
}
static irqreturn_t
armv6pmu_handle_irq(int irq_num,
void *dev)
{
unsigned long pmcr = armv6_pmcr_read();
struct perf_sample_data data;
struct cpu_hw_events *cpuc;
struct pt_regs *regs;
int idx;
if (!armv6_pmcr_has_overflowed(pmcr))
return IRQ_NONE;
regs = get_irq_regs();
/*
* The interrupts are cleared by writing the overflow flags back to
* the control register. All of the other bits don't have any effect
* if they are rewritten, so write the whole value back.
*/
armv6_pmcr_write(pmcr);
perf_sample_data_init(&data, 0);
cpuc = &__get_cpu_var(cpu_hw_events);
for (idx = 0; idx <= armpmu->num_events; ++idx) {
struct perf_event *event = cpuc->events[idx];
struct hw_perf_event *hwc;
if (!test_bit(idx, cpuc->active_mask))
continue;
/*
* We have a single interrupt for all counters. Check that
* each counter has overflowed before we process it.
*/
if (!armv6_pmcr_counter_has_overflowed(pmcr, idx))
continue;
hwc = &event->hw;
armpmu_event_update(event, hwc, idx, 1);
data.period = event->hw.last_period;
if (!armpmu_event_set_period(event, hwc, idx))
continue;
if (perf_event_overflow(event, 0, &data, regs))
armpmu->disable(hwc, idx);
}
/*
* Handle the pending perf events.
*
* Note: this call *must* be run with interrupts disabled. For
* platforms that can have the PMU interrupts raised as an NMI, this
* will not work.
*/
irq_work_run();
return IRQ_HANDLED;
}
static void
armv6pmu_start(void)
{
unsigned long flags, val;
raw_spin_lock_irqsave(&pmu_lock, flags);
val = armv6_pmcr_read();
val |= ARMV6_PMCR_ENABLE;
armv6_pmcr_write(val);
raw_spin_unlock_irqrestore(&pmu_lock, flags);
}
static void
armv6pmu_stop(void)
{
unsigned long flags, val;
raw_spin_lock_irqsave(&pmu_lock, flags);
val = armv6_pmcr_read();
val &= ~ARMV6_PMCR_ENABLE;
armv6_pmcr_write(val);
raw_spin_unlock_irqrestore(&pmu_lock, flags);
}
static int
armv6pmu_get_event_idx(struct cpu_hw_events *cpuc,
struct hw_perf_event *event)
{
/* Always place a cycle counter into the cycle counter. */
if (ARMV6_PERFCTR_CPU_CYCLES == event->config_base) {
if (test_and_set_bit(ARMV6_CYCLE_COUNTER, cpuc->used_mask))
return -EAGAIN;
return ARMV6_CYCLE_COUNTER;
} else {
/*
* For anything other than a cycle counter, try and use
* counter0 and counter1.
*/
if (!test_and_set_bit(ARMV6_COUNTER1, cpuc->used_mask))
return ARMV6_COUNTER1;
if (!test_and_set_bit(ARMV6_COUNTER0, cpuc->used_mask))
return ARMV6_COUNTER0;
/* The counters are all in use. */
return -EAGAIN;
}
}
static void
armv6pmu_disable_event(struct hw_perf_event *hwc,
int idx)
{
unsigned long val, mask, evt, flags;
if (ARMV6_CYCLE_COUNTER == idx) {
mask = ARMV6_PMCR_CCOUNT_IEN;
evt = 0;
} else if (ARMV6_COUNTER0 == idx) {
mask = ARMV6_PMCR_COUNT0_IEN | ARMV6_PMCR_EVT_COUNT0_MASK;
evt = ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT0_SHIFT;
} else if (ARMV6_COUNTER1 == idx) {
mask = ARMV6_PMCR_COUNT1_IEN | ARMV6_PMCR_EVT_COUNT1_MASK;
evt = ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT1_SHIFT;
} else {
WARN_ONCE(1, "invalid counter number (%d)\n", idx);
return;
}
/*
* Mask out the current event and set the counter to count the number
* of ETM bus signal assertion cycles. The external reporting should
* be disabled and so this should never increment.
*/
raw_spin_lock_irqsave(&pmu_lock, flags);
val = armv6_pmcr_read();
val &= ~mask;
val |= evt;
armv6_pmcr_write(val);
raw_spin_unlock_irqrestore(&pmu_lock, flags);
}
static void
armv6mpcore_pmu_disable_event(struct hw_perf_event *hwc,
int idx)
{
unsigned long val, mask, flags, evt = 0;
if (ARMV6_CYCLE_COUNTER == idx) {
mask = ARMV6_PMCR_CCOUNT_IEN;
} else if (ARMV6_COUNTER0 == idx) {
mask = ARMV6_PMCR_COUNT0_IEN;
} else if (ARMV6_COUNTER1 == idx) {
mask = ARMV6_PMCR_COUNT1_IEN;
} else {
WARN_ONCE(1, "invalid counter number (%d)\n", idx);
return;
}
/*
* Unlike UP ARMv6, we don't have a way of stopping the counters. We
* simply disable the interrupt reporting.
*/
raw_spin_lock_irqsave(&pmu_lock, flags);
val = armv6_pmcr_read();
val &= ~mask;
val |= evt;
armv6_pmcr_write(val);
raw_spin_unlock_irqrestore(&pmu_lock, flags);
}
static const struct arm_pmu armv6pmu = {
.id = ARM_PERF_PMU_ID_V6,
.name = "v6",
.handle_irq = armv6pmu_handle_irq,
.enable = armv6pmu_enable_event,
.disable = armv6pmu_disable_event,
.read_counter = armv6pmu_read_counter,
.write_counter = armv6pmu_write_counter,
.get_event_idx = armv6pmu_get_event_idx,
.start = armv6pmu_start,
.stop = armv6pmu_stop,
.cache_map = &armv6_perf_cache_map,
.event_map = &armv6_perf_map,
.raw_event_mask = 0xFF,
.num_events = 3,
.max_period = (1LLU << 32) - 1,
};
static const struct arm_pmu *__init armv6pmu_init(void)
{
return &armv6pmu;
}
/*
* ARMv6mpcore is almost identical to single core ARMv6 with the exception
* that some of the events have different enumerations and that there is no
* *hack* to stop the programmable counters. To stop the counters we simply
* disable the interrupt reporting and update the event. When unthrottling we
* reset the period and enable the interrupt reporting.
*/
static const struct arm_pmu armv6mpcore_pmu = {
.id = ARM_PERF_PMU_ID_V6MP,
.name = "v6mpcore",
.handle_irq = armv6pmu_handle_irq,
.enable = armv6pmu_enable_event,
.disable = armv6mpcore_pmu_disable_event,
.read_counter = armv6pmu_read_counter,
.write_counter = armv6pmu_write_counter,
.get_event_idx = armv6pmu_get_event_idx,
.start = armv6pmu_start,
.stop = armv6pmu_stop,
.cache_map = &armv6mpcore_perf_cache_map,
.event_map = &armv6mpcore_perf_map,
.raw_event_mask = 0xFF,
.num_events = 3,
.max_period = (1LLU << 32) - 1,
};
static const struct arm_pmu *__init armv6mpcore_pmu_init(void)
{
return &armv6mpcore_pmu;
}
#else
static const struct arm_pmu *__init armv6pmu_init(void)
{
return NULL;
}
static const struct arm_pmu *__init armv6mpcore_pmu_init(void)
{
return NULL;
}
#endif /* CONFIG_CPU_V6 || CONFIG_CPU_V6K */
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