/*
* PMU support
*
* Copyright (C) 2012 ARM Limited
* Author: Will Deacon <will.deacon@arm.com>
*
* This code is based heavily on the ARMv7 perf event code.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <asm/irq_regs.h>
#include <linux/of.h>
#include <linux/perf/arm_pmu.h>
#include <linux/platform_device.h>
/*
* ARMv8 PMUv3 Performance Events handling code.
* Common event types.
*/
enum armv8_pmuv3_perf_types {
/* Required events. */
ARMV8_PMUV3_PERFCTR_PMNC_SW_INCR = 0x00,
ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL = 0x03,
ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS = 0x04,
ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED = 0x10,
ARMV8_PMUV3_PERFCTR_CLOCK_CYCLES = 0x11,
ARMV8_PMUV3_PERFCTR_PC_BRANCH_PRED = 0x12,
/* At least one of the following is required. */
ARMV8_PMUV3_PERFCTR_INSTR_EXECUTED = 0x08,
ARMV8_PMUV3_PERFCTR_OP_SPEC = 0x1B,
/* Common architectural events. */
ARMV8_PMUV3_PERFCTR_MEM_READ = 0x06,
ARMV8_PMUV3_PERFCTR_MEM_WRITE = 0x07,
ARMV8_PMUV3_PERFCTR_EXC_TAKEN = 0x09,
ARMV8_PMUV3_PERFCTR_EXC_EXECUTED = 0x0A,
ARMV8_PMUV3_PERFCTR_CID_WRITE = 0x0B,
ARMV8_PMUV3_PERFCTR_PC_WRITE = 0x0C,
ARMV8_PMUV3_PERFCTR_PC_IMM_BRANCH = 0x0D,
ARMV8_PMUV3_PERFCTR_PC_PROC_RETURN = 0x0E,
ARMV8_PMUV3_PERFCTR_MEM_UNALIGNED_ACCESS = 0x0F,
ARMV8_PMUV3_PERFCTR_TTBR_WRITE = 0x1C,
/* Common microarchitectural events. */
ARMV8_PMUV3_PERFCTR_L1_ICACHE_REFILL = 0x01,
ARMV8_PMUV3_PERFCTR_ITLB_REFILL = 0x02,
ARMV8_PMUV3_PERFCTR_DTLB_REFILL = 0x05,
ARMV8_PMUV3_PERFCTR_MEM_ACCESS = 0x13,
ARMV8_PMUV3_PERFCTR_L1_ICACHE_ACCESS = 0x14,
ARMV8_PMUV3_PERFCTR_L1_DCACHE_WB = 0x15,
ARMV8_PMUV3_PERFCTR_L2_CACHE_ACCESS = 0x16,
ARMV8_PMUV3_PERFCTR_L2_CACHE_REFILL = 0x17,
ARMV8_PMUV3_PERFCTR_L2_CACHE_WB = 0x18,
ARMV8_PMUV3_PERFCTR_BUS_ACCESS = 0x19,
ARMV8_PMUV3_PERFCTR_MEM_ERROR = 0x1A,
ARMV8_PMUV3_PERFCTR_BUS_CYCLES = 0x1D,
};
/* PMUv3 HW events mapping. */
static const unsigned armv8_pmuv3_perf_map[PERF_COUNT_HW_MAX] = {
PERF_MAP_ALL_UNSUPPORTED,
[PERF_COUNT_HW_CPU_CYCLES] = ARMV8_PMUV3_PERFCTR_CLOCK_CYCLES,
[PERF_COUNT_HW_INSTRUCTIONS] = ARMV8_PMUV3_PERFCTR_INSTR_EXECUTED,
[PERF_COUNT_HW_CACHE_REFERENCES] = ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS,
[PERF_COUNT_HW_CACHE_MISSES] = ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL,
[PERF_COUNT_HW_BRANCH_MISSES] = ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED,
};
static const unsigned armv8_pmuv3_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
PERF_CACHE_MAP_ALL_UNSUPPORTED,
[C(L1D)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS,
[C(L1D)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL,
[C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS,
[C(L1D)][C(OP_WRITE)][C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL,
[C(BPU)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_PC_BRANCH_PRED,
[C(BPU)][C(OP_READ)][C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED,
[C(BPU)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_PC_BRANCH_PRED,
[C(BPU)][C(OP_WRITE)][C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED,
};
/*
* Perf Events' indices
*/
#define ARMV8_IDX_CYCLE_COUNTER 0
#define ARMV8_IDX_COUNTER0 1
#define ARMV8_IDX_COUNTER_LAST(cpu_pmu) \
(ARMV8_IDX_CYCLE_COUNTER + cpu_pmu->num_events - 1)
#define ARMV8_MAX_COUNTERS 32
#define ARMV8_COUNTER_MASK (ARMV8_MAX_COUNTERS - 1)
/*
* ARMv8 low level PMU access
*/
/*
* Perf Event to low level counters mapping
*/
#define ARMV8_IDX_TO_COUNTER(x) \
(((x) - ARMV8_IDX_COUNTER0) & ARMV8_COUNTER_MASK)
/*
* Per-CPU PMCR: config reg
*/
#define ARMV8_PMCR_E (1 << 0) /* Enable all counters */
#define ARMV8_PMCR_P (1 << 1) /* Reset all counters */
#define ARMV8_PMCR_C (1 << 2) /* Cycle counter reset */
#define ARMV8_PMCR_D (1 << 3) /* CCNT counts every 64th cpu cycle */
#define ARMV8_PMCR_X (1 << 4) /* Export to ETM */
#define ARMV8_PMCR_DP (1 << 5) /* Disable CCNT if non-invasive debug*/
#define ARMV8_PMCR_N_SHIFT 11 /* Number of counters supported */
#define ARMV8_PMCR_N_MASK 0x1f
#define ARMV8_PMCR_MASK 0x3f /* Mask for writable bits */
/*
* PMOVSR: counters overflow flag status reg
*/
#define ARMV8_OVSR_MASK 0xffffffff /* Mask for writable bits */
#define ARMV8_OVERFLOWED_MASK ARMV8_OVSR_MASK
/*
* PMXEVTYPER: Event selection reg
*/
#define ARMV8_EVTYPE_MASK 0xc80003ff /* Mask for writable bits */
#define ARMV8_EVTYPE_EVENT 0x3ff /* Mask for EVENT bits */
/*
* Event filters for PMUv3
*/
#define ARMV8_EXCLUDE_EL1 (1 << 31)
#define ARMV8_EXCLUDE_EL0 (1 << 30)
#define ARMV8_INCLUDE_EL2 (1 << 27)
static inline u32 armv8pmu_pmcr_read(void)
{
u32 val;
asm volatile("mrs %0, pmcr_el0" : "=r" (val));
return val;
}
static inline void armv8pmu_pmcr_write(u32 val)
{
val &= ARMV8_PMCR_MASK;
isb();
asm volatile("msr pmcr_el0, %0" :: "r" (val));
}
static inline int armv8pmu_has_overflowed(u32 pmovsr)
{
return pmovsr & ARMV8_OVERFLOWED_MASK;
}
static inline int armv8pmu_counter_valid(struct arm_pmu *cpu_pmu, int idx)
{
return idx >= ARMV8_IDX_CYCLE_COUNTER &&
idx <= ARMV8_IDX_COUNTER_LAST(cpu_pmu);
}
static inline int armv8pmu_counter_has_overflowed(u32 pmnc, int idx)
{
return pmnc & BIT(ARMV8_IDX_TO_COUNTER(idx));
}
static inline int armv8pmu_select_counter(int idx)
{
u32 counter = ARMV8_IDX_TO_COUNTER(idx);
asm volatile("msr pmselr_el0, %0" :: "r" (counter));
isb();
return idx;
}
static inline u32 armv8pmu_read_counter(struct perf_event *event)
{
struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
u32 value = 0;
if (!armv8pmu_counter_valid(cpu_pmu, idx))
pr_err("CPU%u reading wrong counter %d\n",
smp_processor_id(), idx);
else if (idx == ARMV8_IDX_CYCLE_COUNTER)
asm volatile("mrs %0, pmccntr_el0" : "=r" (value));
else if (armv8pmu_select_counter(idx) == idx)
asm volatile("mrs %0, pmxevcntr_el0" : "=r" (value));
return value;
}
static inline void armv8pmu_write_counter(struct perf_event *event, u32 value)
{
struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
if (!armv8pmu_counter_valid(cpu_pmu, idx))
pr_err("CPU%u writing wrong counter %d\n",
smp_processor_id(), idx);
else if (idx == ARMV8_IDX_CYCLE_COUNTER)
asm volatile("msr pmccntr_el0, %0" :: "r" (value));
else if (armv8pmu_select_counter(idx) == idx)
asm volatile("msr pmxevcntr_el0, %0" :: "r" (value));
}
static inline void armv8pmu_write_evtype(int idx, u32 val)
{
if (armv8pmu_select_counter(idx) == idx) {
val &= ARMV8_EVTYPE_MASK;
asm volatile("msr pmxevtyper_el0, %0" :: "r" (val));
}
}
static inline int armv8pmu_enable_counter(int idx)
{
u32 counter = ARMV8_IDX_TO_COUNTER(idx);
asm volatile("msr pmcntenset_el0, %0" :: "r" (BIT(counter)));
return idx;
}
static inline int armv8pmu_disable_counter(int idx)
{
u32 counter = ARMV8_IDX_TO_COUNTER(idx);
asm volatile("msr pmcntenclr_el0, %0" :: "r" (BIT(counter)));
return idx;
}
static inline int armv8pmu_enable_intens(int idx)
{
u32 counter = ARMV8_IDX_TO_COUNTER(idx);
asm volatile("msr pmintenset_el1, %0" :: "r" (BIT(counter)));
return idx;
}
static inline int armv8pmu_disable_intens(int idx)
{
u32 counter = ARMV8_IDX_TO_COUNTER(idx);
asm volatile("msr pmintenclr_el1, %0" :: "r" (BIT(counter)));
isb();
/* Clear the overflow flag in case an interrupt is pending. */
asm volatile("msr pmovsclr_el0, %0" :: "r" (BIT(counter)));
isb();
return idx;
}
static inline u32 armv8pmu_getreset_flags(void)
{
u32 value;
/* Read */
asm volatile("mrs %0, pmovsclr_el0" : "=r" (value));
/* Write to clear flags */
value &= ARMV8_OVSR_MASK;
asm volatile("msr pmovsclr_el0, %0" :: "r" (value));
return value;
}
static void armv8pmu_enable_event(struct perf_event *event)
{
unsigned long flags;
struct hw_perf_event *hwc = &event->hw;
struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
int idx = hwc->idx;
/*
* Enable counter and interrupt, and set the counter to count
* the event that we're interested in.
*/
raw_spin_lock_irqsave(&events->pmu_lock, flags);
/*
* Disable counter
*/
armv8pmu_disable_counter(idx);
/*
* Set event (if destined for PMNx counters).
*/
armv8pmu_write_evtype(idx, hwc->config_base);
/*
* Enable interrupt for this counter
*/
armv8pmu_enable_intens(idx);
/*
* Enable counter
*/
armv8pmu_enable_counter(idx);
raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}
static void armv8pmu_disable_event(struct perf_event *event)
{
unsigned long flags;
struct hw_perf_event *hwc = &event->hw;
struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
int idx = hwc->idx;
/*
* Disable counter and interrupt
*/
raw_spin_lock_irqsave(&events->pmu_lock, flags);
/*
* Disable counter
*/
armv8pmu_disable_counter(idx);
/*
* Disable interrupt for this counter
*/
armv8pmu_disable_intens(idx);
raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}
static irqreturn_t armv8pmu_handle_irq(int irq_num, void *dev)
{
u32 pmovsr;
struct perf_sample_data data;
struct arm_pmu *cpu_pmu = (struct arm_pmu *)dev;
struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
struct pt_regs *regs;
int idx;
/*
* Get and reset the IRQ flags
*/
pmovsr = armv8pmu_getreset_flags();
/*
* Did an overflow occur?
*/
if (!armv8pmu_has_overflowed(pmovsr))
return IRQ_NONE;
/*
* Handle the counter(s) overflow(s)
*/
regs = get_irq_regs();
for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
struct perf_event *event = cpuc->events[idx];
struct hw_perf_event *hwc;
/* Ignore if we don't have an event. */
if (!event)
continue;
/*
* We have a single interrupt for all counters. Check that
* each counter has overflowed before we process it.
*/
if (!armv8pmu_counter_has_overflowed(pmovsr, idx))
continue;
hwc = &event->hw;
armpmu_event_update(event);
perf_sample_data_init(&data, 0, hwc->last_period);
if (!armpmu_event_set_period(event))
continue;
if (perf_event_overflow(event, &data, regs))
cpu_pmu->disable(event);
}
/*
* 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 armv8pmu_start(struct arm_pmu *cpu_pmu)
{
unsigned long flags;
struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
raw_spin_lock_irqsave(&events->pmu_lock, flags);
/* Enable all counters */
armv8pmu_pmcr_write(armv8pmu_pmcr_read() | ARMV8_PMCR_E);
raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}
static void armv8pmu_stop(struct arm_pmu *cpu_pmu)
{
unsigned long flags;
struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
raw_spin_lock_irqsave(&events->pmu_lock, flags);
/* Disable all counters */
armv8pmu_pmcr_write(armv8pmu_pmcr_read() & ~ARMV8_PMCR_E);
raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}
static int armv8pmu_get_event_idx(struct pmu_hw_events *cpuc,
struct perf_event *event)
{
int idx;
struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
struct hw_perf_event *hwc = &event->hw;
unsigned long evtype = hwc->config_base & ARMV8_EVTYPE_EVENT;
/* Always place a cycle counter into the cycle counter. */
if (evtype == ARMV8_PMUV3_PERFCTR_CLOCK_CYCLES) {
if (test_and_set_bit(ARMV8_IDX_CYCLE_COUNTER, cpuc->used_mask))
return -EAGAIN;
return ARMV8_IDX_CYCLE_COUNTER;
}
/*
* For anything other than a cycle counter, try and use
* the events counters
*/
for (idx = ARMV8_IDX_COUNTER0; idx < cpu_pmu->num_events; ++idx) {
if (!test_and_set_bit(idx, cpuc->used_mask))
return idx;
}
/* The counters are all in use. */
return -EAGAIN;
}
/*
* Add an event filter to a given event. This will only work for PMUv2 PMUs.
*/
static int armv8pmu_set_event_filter(struct hw_perf_event *event,
struct perf_event_attr *attr)
{
unsigned long config_base = 0;
if (attr->exclude_idle)
return -EPERM;
if (attr->exclude_user)
config_base |= ARMV8_EXCLUDE_EL0;
if (attr->exclude_kernel)
config_base |= ARMV8_EXCLUDE_EL1;
if (!attr->exclude_hv)
config_base |= ARMV8_INCLUDE_EL2;
/*
* Install the filter into config_base as this is used to
* construct the event type.
*/
event->config_base = config_base;
return 0;
}
static void armv8pmu_reset(void *info)
{
struct arm_pmu *cpu_pmu = (struct arm_pmu *)info;
u32 idx, nb_cnt = cpu_pmu->num_events;
/* The counter and interrupt enable registers are unknown at reset. */
for (idx = ARMV8_IDX_CYCLE_COUNTER; idx < nb_cnt; ++idx) {
armv8pmu_disable_counter(idx);
armv8pmu_disable_intens(idx);
}
/* Initialize & Reset PMNC: C and P bits. */
armv8pmu_pmcr_write(ARMV8_PMCR_P | ARMV8_PMCR_C);
/* Disable access from userspace. */
asm volatile("msr pmuserenr_el0, %0" :: "r" (0));
}
static int armv8_pmuv3_map_event(struct perf_event *event)
{
return armpmu_map_event(event, &armv8_pmuv3_perf_map,
&armv8_pmuv3_perf_cache_map,
ARMV8_EVTYPE_EVENT);
}
static void armv8pmu_read_num_pmnc_events(void *info)
{
int *nb_cnt = info;
/* Read the nb of CNTx counters supported from PMNC */
*nb_cnt = (armv8pmu_pmcr_read() >> ARMV8_PMCR_N_SHIFT) & ARMV8_PMCR_N_MASK;
/* Add the CPU cycles counter */
*nb_cnt += 1;
}
static int armv8pmu_probe_num_events(struct arm_pmu *arm_pmu)
{
return smp_call_function_any(&arm_pmu->supported_cpus,
armv8pmu_read_num_pmnc_events,
&arm_pmu->num_events, 1);
}
static int armv8_pmuv3_init(struct arm_pmu *cpu_pmu)
{
cpu_pmu->handle_irq = armv8pmu_handle_irq,
cpu_pmu->enable = armv8pmu_enable_event,
cpu_pmu->disable = armv8pmu_disable_event,
cpu_pmu->read_counter = armv8pmu_read_counter,
cpu_pmu->write_counter = armv8pmu_write_counter,
cpu_pmu->get_event_idx = armv8pmu_get_event_idx,
cpu_pmu->start = armv8pmu_start,
cpu_pmu->stop = armv8pmu_stop,
cpu_pmu->reset = armv8pmu_reset,
cpu_pmu->max_period = (1LLU << 32) - 1,
cpu_pmu->name = "armv8_pmuv3";
cpu_pmu->map_event = armv8_pmuv3_map_event;
cpu_pmu->set_event_filter = armv8pmu_set_event_filter;
return armv8pmu_probe_num_events(cpu_pmu);
}
static const struct of_device_id armv8_pmu_of_device_ids[] = {
{.compatible = "arm,armv8-pmuv3", .data = armv8_pmuv3_init},
{},
};
static int armv8_pmu_device_probe(struct platform_device *pdev)
{
return arm_pmu_device_probe(pdev, armv8_pmu_of_device_ids, NULL);
}
static struct platform_driver armv8_pmu_driver = {
.driver = {
.name = "armv8-pmu",
.of_match_table = armv8_pmu_of_device_ids,
},
.probe = armv8_pmu_device_probe,
};
static int __init register_armv8_pmu_driver(void)
{
return platform_driver_register(&armv8_pmu_driver);
}
device_initcall(register_armv8_pmu_driver);
