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OpenCloudOS-Kernel/drivers/perf/riscv_pmu_sbi.c

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// SPDX-License-Identifier: GPL-2.0
/*
* RISC-V performance counter support.
*
* Copyright (C) 2021 Western Digital Corporation or its affiliates.
*
* This code is based on ARM perf event code which is in turn based on
* sparc64 and x86 code.
*/
#define pr_fmt(fmt) "riscv-pmu-sbi: " fmt
#include <linux/mod_devicetable.h>
#include <linux/perf/riscv_pmu.h>
#include <linux/platform_device.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/of_irq.h>
#include <linux/of.h>
#include <asm/sbi.h>
#include <asm/hwcap.h>
union sbi_pmu_ctr_info {
unsigned long value;
struct {
unsigned long csr:12;
unsigned long width:6;
#if __riscv_xlen == 32
unsigned long reserved:13;
#else
unsigned long reserved:45;
#endif
unsigned long type:1;
};
};
/*
* RISC-V doesn't have hetergenous harts yet. This need to be part of
* per_cpu in case of harts with different pmu counters
*/
static union sbi_pmu_ctr_info *pmu_ctr_list;
static unsigned int riscv_pmu_irq;
struct sbi_pmu_event_data {
union {
union {
struct hw_gen_event {
uint32_t event_code:16;
uint32_t event_type:4;
uint32_t reserved:12;
} hw_gen_event;
struct hw_cache_event {
uint32_t result_id:1;
uint32_t op_id:2;
uint32_t cache_id:13;
uint32_t event_type:4;
uint32_t reserved:12;
} hw_cache_event;
};
uint32_t event_idx;
};
};
static const struct sbi_pmu_event_data pmu_hw_event_map[] = {
[PERF_COUNT_HW_CPU_CYCLES] = {.hw_gen_event = {
SBI_PMU_HW_CPU_CYCLES,
SBI_PMU_EVENT_TYPE_HW, 0}},
[PERF_COUNT_HW_INSTRUCTIONS] = {.hw_gen_event = {
SBI_PMU_HW_INSTRUCTIONS,
SBI_PMU_EVENT_TYPE_HW, 0}},
[PERF_COUNT_HW_CACHE_REFERENCES] = {.hw_gen_event = {
SBI_PMU_HW_CACHE_REFERENCES,
SBI_PMU_EVENT_TYPE_HW, 0}},
[PERF_COUNT_HW_CACHE_MISSES] = {.hw_gen_event = {
SBI_PMU_HW_CACHE_MISSES,
SBI_PMU_EVENT_TYPE_HW, 0}},
[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = {.hw_gen_event = {
SBI_PMU_HW_BRANCH_INSTRUCTIONS,
SBI_PMU_EVENT_TYPE_HW, 0}},
[PERF_COUNT_HW_BRANCH_MISSES] = {.hw_gen_event = {
SBI_PMU_HW_BRANCH_MISSES,
SBI_PMU_EVENT_TYPE_HW, 0}},
[PERF_COUNT_HW_BUS_CYCLES] = {.hw_gen_event = {
SBI_PMU_HW_BUS_CYCLES,
SBI_PMU_EVENT_TYPE_HW, 0}},
[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = {.hw_gen_event = {
SBI_PMU_HW_STALLED_CYCLES_FRONTEND,
SBI_PMU_EVENT_TYPE_HW, 0}},
[PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = {.hw_gen_event = {
SBI_PMU_HW_STALLED_CYCLES_BACKEND,
SBI_PMU_EVENT_TYPE_HW, 0}},
[PERF_COUNT_HW_REF_CPU_CYCLES] = {.hw_gen_event = {
SBI_PMU_HW_REF_CPU_CYCLES,
SBI_PMU_EVENT_TYPE_HW, 0}},
};
#define C(x) PERF_COUNT_HW_CACHE_##x
static const struct sbi_pmu_event_data pmu_cache_event_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)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_READ), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_READ), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_WRITE), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_WRITE), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_PREFETCH), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_PREFETCH), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
},
[C(L1I)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_READ), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_READ),
C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_WRITE), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_WRITE), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_PREFETCH), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_PREFETCH), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
},
[C(LL)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_READ), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_READ), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_WRITE), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_WRITE), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_PREFETCH), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_PREFETCH), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
},
[C(DTLB)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_READ), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_READ), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_WRITE), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_WRITE), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_PREFETCH), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_PREFETCH), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
},
[C(ITLB)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_READ), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_READ), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_WRITE), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_WRITE), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_PREFETCH), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_PREFETCH), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
},
[C(BPU)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_READ), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_READ), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_WRITE), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_WRITE), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_PREFETCH), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_PREFETCH), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
},
[C(NODE)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_READ), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_READ), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_WRITE), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_WRITE), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
C(OP_PREFETCH), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
C(OP_PREFETCH), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
},
},
};
static int pmu_sbi_ctr_get_width(int idx)
{
return pmu_ctr_list[idx].width;
}
static bool pmu_sbi_ctr_is_fw(int cidx)
{
union sbi_pmu_ctr_info *info;
info = &pmu_ctr_list[cidx];
if (!info)
return false;
return (info->type == SBI_PMU_CTR_TYPE_FW) ? true : false;
}
static int pmu_sbi_ctr_get_idx(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu);
struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
struct sbiret ret;
int idx;
uint64_t cbase = 0;
uint64_t cmask = GENMASK_ULL(rvpmu->num_counters - 1, 0);
unsigned long cflags = 0;
if (event->attr.exclude_kernel)
cflags |= SBI_PMU_CFG_FLAG_SET_SINH;
if (event->attr.exclude_user)
cflags |= SBI_PMU_CFG_FLAG_SET_UINH;
/* retrieve the available counter index */
ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase, cmask,
cflags, hwc->event_base, hwc->config, 0);
if (ret.error) {
pr_debug("Not able to find a counter for event %lx config %llx\n",
hwc->event_base, hwc->config);
return sbi_err_map_linux_errno(ret.error);
}
idx = ret.value;
if (idx >= rvpmu->num_counters || !pmu_ctr_list[idx].value)
return -ENOENT;
/* Additional sanity check for the counter id */
if (pmu_sbi_ctr_is_fw(idx)) {
if (!test_and_set_bit(idx, cpuc->used_fw_ctrs))
return idx;
} else {
if (!test_and_set_bit(idx, cpuc->used_hw_ctrs))
return idx;
}
return -ENOENT;
}
static void pmu_sbi_ctr_clear_idx(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu);
struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
int idx = hwc->idx;
if (pmu_sbi_ctr_is_fw(idx))
clear_bit(idx, cpuc->used_fw_ctrs);
else
clear_bit(idx, cpuc->used_hw_ctrs);
}
static int pmu_event_find_cache(u64 config)
{
unsigned int cache_type, cache_op, cache_result, ret;
cache_type = (config >> 0) & 0xff;
if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
return -EINVAL;
cache_op = (config >> 8) & 0xff;
if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
return -EINVAL;
cache_result = (config >> 16) & 0xff;
if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
return -EINVAL;
ret = pmu_cache_event_map[cache_type][cache_op][cache_result].event_idx;
return ret;
}
static bool pmu_sbi_is_fw_event(struct perf_event *event)
{
u32 type = event->attr.type;
u64 config = event->attr.config;
if ((type == PERF_TYPE_RAW) && ((config >> 63) == 1))
return true;
else
return false;
}
static int pmu_sbi_event_map(struct perf_event *event, u64 *econfig)
{
u32 type = event->attr.type;
u64 config = event->attr.config;
int bSoftware;
u64 raw_config_val;
int ret;
switch (type) {
case PERF_TYPE_HARDWARE:
if (config >= PERF_COUNT_HW_MAX)
return -EINVAL;
ret = pmu_hw_event_map[event->attr.config].event_idx;
break;
case PERF_TYPE_HW_CACHE:
ret = pmu_event_find_cache(config);
break;
case PERF_TYPE_RAW:
/*
* As per SBI specification, the upper 16 bits must be unused for
* a raw event. Use the MSB (63b) to distinguish between hardware
* raw event and firmware events.
*/
bSoftware = config >> 63;
raw_config_val = config & RISCV_PMU_RAW_EVENT_MASK;
if (bSoftware) {
if (raw_config_val < SBI_PMU_FW_MAX)
ret = (raw_config_val & 0xFFFF) |
(SBI_PMU_EVENT_TYPE_FW << 16);
else
return -EINVAL;
} else {
ret = RISCV_PMU_RAW_EVENT_IDX;
*econfig = raw_config_val;
}
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
static u64 pmu_sbi_ctr_read(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
struct sbiret ret;
union sbi_pmu_ctr_info info;
u64 val = 0;
if (pmu_sbi_is_fw_event(event)) {
ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_FW_READ,
hwc->idx, 0, 0, 0, 0, 0);
if (!ret.error)
val = ret.value;
} else {
info = pmu_ctr_list[idx];
val = riscv_pmu_ctr_read_csr(info.csr);
if (IS_ENABLED(CONFIG_32BIT))
val = ((u64)riscv_pmu_ctr_read_csr(info.csr + 0x80)) << 31 | val;
}
return val;
}
static void pmu_sbi_ctr_start(struct perf_event *event, u64 ival)
{
struct sbiret ret;
struct hw_perf_event *hwc = &event->hw;
unsigned long flag = SBI_PMU_START_FLAG_SET_INIT_VALUE;
ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, hwc->idx,
1, flag, ival, ival >> 32, 0);
if (ret.error && (ret.error != SBI_ERR_ALREADY_STARTED))
pr_err("Starting counter idx %d failed with error %d\n",
hwc->idx, sbi_err_map_linux_errno(ret.error));
}
static void pmu_sbi_ctr_stop(struct perf_event *event, unsigned long flag)
{
struct sbiret ret;
struct hw_perf_event *hwc = &event->hw;
ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, hwc->idx, 1, flag, 0, 0, 0);
if (ret.error && (ret.error != SBI_ERR_ALREADY_STOPPED) &&
flag != SBI_PMU_STOP_FLAG_RESET)
pr_err("Stopping counter idx %d failed with error %d\n",
hwc->idx, sbi_err_map_linux_errno(ret.error));
}
static int pmu_sbi_find_num_ctrs(void)
{
struct sbiret ret;
ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_NUM_COUNTERS, 0, 0, 0, 0, 0, 0);
if (!ret.error)
return ret.value;
else
return sbi_err_map_linux_errno(ret.error);
}
static int pmu_sbi_get_ctrinfo(int nctr)
{
struct sbiret ret;
int i, num_hw_ctr = 0, num_fw_ctr = 0;
union sbi_pmu_ctr_info cinfo;
pmu_ctr_list = kcalloc(nctr, sizeof(*pmu_ctr_list), GFP_KERNEL);
if (!pmu_ctr_list)
return -ENOMEM;
for (i = 0; i <= nctr; i++) {
ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_GET_INFO, i, 0, 0, 0, 0, 0);
if (ret.error)
/* The logical counter ids are not expected to be contiguous */
continue;
cinfo.value = ret.value;
if (cinfo.type == SBI_PMU_CTR_TYPE_FW)
num_fw_ctr++;
else
num_hw_ctr++;
pmu_ctr_list[i].value = cinfo.value;
}
pr_info("%d firmware and %d hardware counters\n", num_fw_ctr, num_hw_ctr);
return 0;
}
static inline void pmu_sbi_stop_all(struct riscv_pmu *pmu)
{
/*
* No need to check the error because we are disabling all the counters
* which may include counters that are not enabled yet.
*/
sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP,
0, GENMASK_ULL(pmu->num_counters - 1, 0), 0, 0, 0, 0);
}
static inline void pmu_sbi_stop_hw_ctrs(struct riscv_pmu *pmu)
{
struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
/* No need to check the error here as we can't do anything about the error */
sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, 0,
cpu_hw_evt->used_hw_ctrs[0], 0, 0, 0, 0);
}
/*
* This function starts all the used counters in two step approach.
* Any counter that did not overflow can be start in a single step
* while the overflowed counters need to be started with updated initialization
* value.
*/
static inline void pmu_sbi_start_overflow_mask(struct riscv_pmu *pmu,
unsigned long ctr_ovf_mask)
{
int idx = 0;
struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
struct perf_event *event;
unsigned long flag = SBI_PMU_START_FLAG_SET_INIT_VALUE;
unsigned long ctr_start_mask = 0;
uint64_t max_period;
struct hw_perf_event *hwc;
u64 init_val = 0;
ctr_start_mask = cpu_hw_evt->used_hw_ctrs[0] & ~ctr_ovf_mask;
/* Start all the counters that did not overflow in a single shot */
sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, 0, ctr_start_mask,
0, 0, 0, 0);
/* Reinitialize and start all the counter that overflowed */
while (ctr_ovf_mask) {
if (ctr_ovf_mask & 0x01) {
event = cpu_hw_evt->events[idx];
hwc = &event->hw;
max_period = riscv_pmu_ctr_get_width_mask(event);
init_val = local64_read(&hwc->prev_count) & max_period;
sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1,
flag, init_val, 0, 0);
}
ctr_ovf_mask = ctr_ovf_mask >> 1;
idx++;
}
}
static irqreturn_t pmu_sbi_ovf_handler(int irq, void *dev)
{
struct perf_sample_data data;
struct pt_regs *regs;
struct hw_perf_event *hw_evt;
union sbi_pmu_ctr_info *info;
int lidx, hidx, fidx;
struct riscv_pmu *pmu;
struct perf_event *event;
unsigned long overflow;
unsigned long overflowed_ctrs = 0;
struct cpu_hw_events *cpu_hw_evt = dev;
if (WARN_ON_ONCE(!cpu_hw_evt))
return IRQ_NONE;
/* Firmware counter don't support overflow yet */
fidx = find_first_bit(cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS);
event = cpu_hw_evt->events[fidx];
if (!event) {
csr_clear(CSR_SIP, SIP_LCOFIP);
return IRQ_NONE;
}
pmu = to_riscv_pmu(event->pmu);
pmu_sbi_stop_hw_ctrs(pmu);
/* Overflow status register should only be read after counter are stopped */
overflow = csr_read(CSR_SSCOUNTOVF);
/*
* Overflow interrupt pending bit should only be cleared after stopping
* all the counters to avoid any race condition.
*/
csr_clear(CSR_SIP, SIP_LCOFIP);
/* No overflow bit is set */
if (!overflow)
return IRQ_NONE;
regs = get_irq_regs();
for_each_set_bit(lidx, cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS) {
struct perf_event *event = cpu_hw_evt->events[lidx];
/* Skip if invalid event or user did not request a sampling */
if (!event || !is_sampling_event(event))
continue;
info = &pmu_ctr_list[lidx];
/* Do a sanity check */
if (!info || info->type != SBI_PMU_CTR_TYPE_HW)
continue;
/* compute hardware counter index */
hidx = info->csr - CSR_CYCLE;
/* check if the corresponding bit is set in sscountovf */
if (!(overflow & (1 << hidx)))
continue;
/*
* Keep a track of overflowed counters so that they can be started
* with updated initial value.
*/
overflowed_ctrs |= 1 << lidx;
hw_evt = &event->hw;
riscv_pmu_event_update(event);
perf_sample_data_init(&data, 0, hw_evt->last_period);
if (riscv_pmu_event_set_period(event)) {
/*
* Unlike other ISAs, RISC-V don't have to disable interrupts
* to avoid throttling here. As per the specification, the
* interrupt remains disabled until the OF bit is set.
* Interrupts are enabled again only during the start.
* TODO: We will need to stop the guest counters once
* virtualization support is added.
*/
perf_event_overflow(event, &data, regs);
}
}
pmu_sbi_start_overflow_mask(pmu, overflowed_ctrs);
return IRQ_HANDLED;
}
static int pmu_sbi_starting_cpu(unsigned int cpu, struct hlist_node *node)
{
struct riscv_pmu *pmu = hlist_entry_safe(node, struct riscv_pmu, node);
struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
/* Enable the access for TIME csr only from the user mode now */
csr_write(CSR_SCOUNTEREN, 0x2);
/* Stop all the counters so that they can be enabled from perf */
pmu_sbi_stop_all(pmu);
if (riscv_isa_extension_available(NULL, SSCOFPMF)) {
cpu_hw_evt->irq = riscv_pmu_irq;
csr_clear(CSR_IP, BIT(RV_IRQ_PMU));
csr_set(CSR_IE, BIT(RV_IRQ_PMU));
enable_percpu_irq(riscv_pmu_irq, IRQ_TYPE_NONE);
}
return 0;
}
static int pmu_sbi_dying_cpu(unsigned int cpu, struct hlist_node *node)
{
if (riscv_isa_extension_available(NULL, SSCOFPMF)) {
disable_percpu_irq(riscv_pmu_irq);
csr_clear(CSR_IE, BIT(RV_IRQ_PMU));
}
/* Disable all counters access for user mode now */
csr_write(CSR_SCOUNTEREN, 0x0);
return 0;
}
static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pdev)
{
int ret;
struct cpu_hw_events __percpu *hw_events = pmu->hw_events;
struct device_node *cpu, *child;
struct irq_domain *domain = NULL;
if (!riscv_isa_extension_available(NULL, SSCOFPMF))
return -EOPNOTSUPP;
for_each_of_cpu_node(cpu) {
child = of_get_compatible_child(cpu, "riscv,cpu-intc");
if (!child) {
pr_err("Failed to find INTC node\n");
return -ENODEV;
}
domain = irq_find_host(child);
of_node_put(child);
if (domain)
break;
}
if (!domain) {
pr_err("Failed to find INTC IRQ root domain\n");
return -ENODEV;
}
riscv_pmu_irq = irq_create_mapping(domain, RV_IRQ_PMU);
if (!riscv_pmu_irq) {
pr_err("Failed to map PMU interrupt for node\n");
return -ENODEV;
}
ret = request_percpu_irq(riscv_pmu_irq, pmu_sbi_ovf_handler, "riscv-pmu", hw_events);
if (ret) {
pr_err("registering percpu irq failed [%d]\n", ret);
return ret;
}
return 0;
}
static int pmu_sbi_device_probe(struct platform_device *pdev)
{
struct riscv_pmu *pmu = NULL;
int num_counters;
int ret = -ENODEV;
pr_info("SBI PMU extension is available\n");
pmu = riscv_pmu_alloc();
if (!pmu)
return -ENOMEM;
num_counters = pmu_sbi_find_num_ctrs();
if (num_counters < 0) {
pr_err("SBI PMU extension doesn't provide any counters\n");
goto out_free;
}
/* cache all the information about counters now */
if (pmu_sbi_get_ctrinfo(num_counters))
goto out_free;
ret = pmu_sbi_setup_irqs(pmu, pdev);
if (ret < 0) {
pr_info("Perf sampling/filtering is not supported as sscof extension is not available\n");
pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE;
}
pmu->num_counters = num_counters;
pmu->ctr_start = pmu_sbi_ctr_start;
pmu->ctr_stop = pmu_sbi_ctr_stop;
pmu->event_map = pmu_sbi_event_map;
pmu->ctr_get_idx = pmu_sbi_ctr_get_idx;
pmu->ctr_get_width = pmu_sbi_ctr_get_width;
pmu->ctr_clear_idx = pmu_sbi_ctr_clear_idx;
pmu->ctr_read = pmu_sbi_ctr_read;
ret = cpuhp_state_add_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node);
if (ret)
return ret;
ret = perf_pmu_register(&pmu->pmu, "cpu", PERF_TYPE_RAW);
if (ret) {
cpuhp_state_remove_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node);
return ret;
}
return 0;
out_free:
kfree(pmu);
return ret;
}
static struct platform_driver pmu_sbi_driver = {
.probe = pmu_sbi_device_probe,
.driver = {
.name = RISCV_PMU_PDEV_NAME,
},
};
static int __init pmu_sbi_devinit(void)
{
int ret;
struct platform_device *pdev;
if (sbi_spec_version < sbi_mk_version(0, 3) ||
sbi_probe_extension(SBI_EXT_PMU) <= 0) {
return 0;
}
ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_RISCV_STARTING,
"perf/riscv/pmu:starting",
pmu_sbi_starting_cpu, pmu_sbi_dying_cpu);
if (ret) {
pr_err("CPU hotplug notifier could not be registered: %d\n",
ret);
return ret;
}
ret = platform_driver_register(&pmu_sbi_driver);
if (ret)
return ret;
pdev = platform_device_register_simple(RISCV_PMU_PDEV_NAME, -1, NULL, 0);
if (IS_ERR(pdev)) {
platform_driver_unregister(&pmu_sbi_driver);
return PTR_ERR(pdev);
}
/* Notify legacy implementation that SBI pmu is available*/
riscv_pmu_legacy_skip_init();
return ret;
}
device_initcall(pmu_sbi_devinit)
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