// 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 <linux/cpu_pm.h>
#include <linux/sched/clock.h>
#include <asm/errata_list.h>
#include <asm/sbi.h>
#include <asm/hwcap.h>
#define SYSCTL_NO_USER_ACCESS 0
#define SYSCTL_USER_ACCESS 1
#define SYSCTL_LEGACY 2
#define PERF_EVENT_FLAG_NO_USER_ACCESS BIT(SYSCTL_NO_USER_ACCESS)
#define PERF_EVENT_FLAG_USER_ACCESS BIT(SYSCTL_USER_ACCESS)
#define PERF_EVENT_FLAG_LEGACY BIT(SYSCTL_LEGACY)
PMU_FORMAT_ATTR(event, "config:0-47");
PMU_FORMAT_ATTR(firmware, "config:63");
static struct attribute *riscv_arch_formats_attr[] = {
&format_attr_event.attr,
&format_attr_firmware.attr,
NULL,
};
static struct attribute_group riscv_pmu_format_group = {
.name = "format",
.attrs = riscv_arch_formats_attr,
};
static const struct attribute_group *riscv_pmu_attr_groups[] = {
&riscv_pmu_format_group,
NULL,
};
/* Allow user mode access by default */
static int sysctl_perf_user_access __read_mostly = SYSCTL_USER_ACCESS;
/*
* RISC-V doesn't have heterogeneous 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 bool riscv_pmu_use_irq;
static unsigned int riscv_pmu_irq_num;
static unsigned int riscv_pmu_irq;
/* Cache the available counters in a bitmask */
static unsigned long cmask;
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;
}
/*
* Returns the counter width of a programmable counter and number of hardware
* counters. As we don't support heterogeneous CPUs yet, it is okay to just
* return the counter width of the first programmable counter.
*/
int riscv_pmu_get_hpm_info(u32 *hw_ctr_width, u32 *num_hw_ctr)
{
int i;
union sbi_pmu_ctr_info *info;
u32 hpm_width = 0, hpm_count = 0;
if (!cmask)
return -EINVAL;
for_each_set_bit(i, &cmask, RISCV_MAX_COUNTERS) {
info = &pmu_ctr_list[i];
if (!info)
continue;
if (!hpm_width && info->csr != CSR_CYCLE && info->csr != CSR_INSTRET)
hpm_width = info->width;
if (info->type == SBI_PMU_CTR_TYPE_HW)
hpm_count++;
}
*hw_ctr_width = hpm_width;
*num_hw_ctr = hpm_count;
return 0;
}
EXPORT_SYMBOL_GPL(riscv_pmu_get_hpm_info);
static uint8_t pmu_sbi_csr_index(struct perf_event *event)
{
return pmu_ctr_list[event->hw.idx].csr - CSR_CYCLE;
}
static unsigned long pmu_sbi_get_filter_flags(struct perf_event *event)
{
unsigned long cflags = 0;
bool guest_events = false;
if (event->attr.config1 & RISCV_PMU_CONFIG1_GUEST_EVENTS)
guest_events = true;
if (event->attr.exclude_kernel)
cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VSINH : SBI_PMU_CFG_FLAG_SET_SINH;
if (event->attr.exclude_user)
cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VUINH : SBI_PMU_CFG_FLAG_SET_UINH;
if (guest_events && event->attr.exclude_hv)
cflags |= SBI_PMU_CFG_FLAG_SET_SINH;
if (event->attr.exclude_host)
cflags |= SBI_PMU_CFG_FLAG_SET_UINH | SBI_PMU_CFG_FLAG_SET_SINH;
if (event->attr.exclude_guest)
cflags |= SBI_PMU_CFG_FLAG_SET_VSINH | SBI_PMU_CFG_FLAG_SET_VUINH;
return cflags;
}
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, cmask = rvpmu->cmask;
unsigned long cflags = 0;
cflags = pmu_sbi_get_filter_flags(event);
/*
* In legacy mode, we have to force the fixed counters for those events
* but not in the user access mode as we want to use the other counters
* that support sampling/filtering.
*/
if (hwc->flags & PERF_EVENT_FLAG_LEGACY) {
if (event->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
cflags |= SBI_PMU_CFG_FLAG_SKIP_MATCH;
cmask = 1;
} else if (event->attr.config == PERF_COUNT_HW_INSTRUCTIONS) {
cflags |= SBI_PMU_CFG_FLAG_SKIP_MATCH;
cmask = 1UL << (CSR_INSTRET - CSR_CYCLE);
}
}
/* retrieve the available counter index */
#if defined(CONFIG_32BIT)
ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase,
cmask, cflags, hwc->event_base, hwc->config,
hwc->config >> 32);
#else
ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase,
cmask, cflags, hwc->event_base, hwc->config, 0);
#endif
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 (!test_bit(idx, &rvpmu->cmask) || !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) {
ret = (raw_config_val & 0xFFFF) |
(SBI_PMU_EVENT_TYPE_FW << 16);
} 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_set_scounteren(void *arg)
{
struct perf_event *event = (struct perf_event *)arg;
if (event->hw.idx != -1)
csr_write(CSR_SCOUNTEREN,
csr_read(CSR_SCOUNTEREN) | (1 << pmu_sbi_csr_index(event)));
}
static void pmu_sbi_reset_scounteren(void *arg)
{
struct perf_event *event = (struct perf_event *)arg;
if (event->hw.idx != -1)
csr_write(CSR_SCOUNTEREN,
csr_read(CSR_SCOUNTEREN) & ~(1 << pmu_sbi_csr_index(event)));
}
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;
#if defined(CONFIG_32BIT)
ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, hwc->idx,
1, flag, ival, ival >> 32, 0);
#else
ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, hwc->idx,
1, flag, ival, 0, 0);
#endif
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));
if ((hwc->flags & PERF_EVENT_FLAG_USER_ACCESS) &&
(hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
on_each_cpu_mask(mm_cpumask(event->owner->mm),
pmu_sbi_set_scounteren, (void *)event, 1);
}
static void pmu_sbi_ctr_stop(struct perf_event *event, unsigned long flag)
{
struct sbiret ret;
struct hw_perf_event *hwc = &event->hw;
if ((hwc->flags & PERF_EVENT_FLAG_USER_ACCESS) &&
(hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
on_each_cpu_mask(mm_cpumask(event->owner->mm),
pmu_sbi_reset_scounteren, (void *)event, 1);
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, unsigned long *mask)
{
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;
*mask |= BIT(i);
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, pmu->cmask, 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;
#if defined(CONFIG_32BIT)
sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1,
flag, init_val, init_val >> 32, 0);
#else
sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1,
flag, init_val, 0, 0);
#endif
perf_event_update_userpage(event);
}
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;
u64 start_clock = sched_clock();
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, BIT(riscv_pmu_irq_num));
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 */
ALT_SBI_PMU_OVERFLOW(overflow);
/*
* Overflow interrupt pending bit should only be cleared after stopping
* all the counters to avoid any race condition.
*/
csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num));
/* 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);
perf_sample_event_took(sched_clock() - start_clock);
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);
/*
* We keep enabling userspace access to CYCLE, TIME and INSTRET via the
* legacy option but that will be removed in the future.
*/
if (sysctl_perf_user_access == SYSCTL_LEGACY)
csr_write(CSR_SCOUNTEREN, 0x7);
else
csr_write(CSR_SCOUNTEREN, 0x2);
/* Stop all the counters so that they can be enabled from perf */
pmu_sbi_stop_all(pmu);
if (riscv_pmu_use_irq) {
cpu_hw_evt->irq = riscv_pmu_irq;
csr_clear(CSR_IP, BIT(riscv_pmu_irq_num));
csr_set(CSR_IE, BIT(riscv_pmu_irq_num));
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_pmu_use_irq) {
disable_percpu_irq(riscv_pmu_irq);
csr_clear(CSR_IE, BIT(riscv_pmu_irq_num));
}
/* 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 irq_domain *domain = NULL;
if (riscv_isa_extension_available(NULL, SSCOFPMF)) {
riscv_pmu_irq_num = RV_IRQ_PMU;
riscv_pmu_use_irq = true;
} else if (IS_ENABLED(CONFIG_ERRATA_THEAD_PMU) &&
riscv_cached_mvendorid(0) == THEAD_VENDOR_ID &&
riscv_cached_marchid(0) == 0 &&
riscv_cached_mimpid(0) == 0) {
riscv_pmu_irq_num = THEAD_C9XX_RV_IRQ_PMU;
riscv_pmu_use_irq = true;
}
if (!riscv_pmu_use_irq)
return -EOPNOTSUPP;
domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
DOMAIN_BUS_ANY);
if (!domain) {
pr_err("Failed to find INTC IRQ root domain\n");
return -ENODEV;
}
riscv_pmu_irq = irq_create_mapping(domain, riscv_pmu_irq_num);
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;
}
#ifdef CONFIG_CPU_PM
static int riscv_pm_pmu_notify(struct notifier_block *b, unsigned long cmd,
void *v)
{
struct riscv_pmu *rvpmu = container_of(b, struct riscv_pmu, riscv_pm_nb);
struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
int enabled = bitmap_weight(cpuc->used_hw_ctrs, RISCV_MAX_COUNTERS);
struct perf_event *event;
int idx;
if (!enabled)
return NOTIFY_OK;
for (idx = 0; idx < RISCV_MAX_COUNTERS; idx++) {
event = cpuc->events[idx];
if (!event)
continue;
switch (cmd) {
case CPU_PM_ENTER:
/*
* Stop and update the counter
*/
riscv_pmu_stop(event, PERF_EF_UPDATE);
break;
case CPU_PM_EXIT:
case CPU_PM_ENTER_FAILED:
/*
* Restore and enable the counter.
*/
riscv_pmu_start(event, PERF_EF_RELOAD);
break;
default:
break;
}
}
return NOTIFY_OK;
}
static int riscv_pm_pmu_register(struct riscv_pmu *pmu)
{
pmu->riscv_pm_nb.notifier_call = riscv_pm_pmu_notify;
return cpu_pm_register_notifier(&pmu->riscv_pm_nb);
}
static void riscv_pm_pmu_unregister(struct riscv_pmu *pmu)
{
cpu_pm_unregister_notifier(&pmu->riscv_pm_nb);
}
#else
static inline int riscv_pm_pmu_register(struct riscv_pmu *pmu) { return 0; }
static inline void riscv_pm_pmu_unregister(struct riscv_pmu *pmu) { }
#endif
static void riscv_pmu_destroy(struct riscv_pmu *pmu)
{
riscv_pm_pmu_unregister(pmu);
cpuhp_state_remove_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node);
}
static void pmu_sbi_event_init(struct perf_event *event)
{
/*
* The permissions are set at event_init so that we do not depend
* on the sysctl value that can change.
*/
if (sysctl_perf_user_access == SYSCTL_NO_USER_ACCESS)
event->hw.flags |= PERF_EVENT_FLAG_NO_USER_ACCESS;
else if (sysctl_perf_user_access == SYSCTL_USER_ACCESS)
event->hw.flags |= PERF_EVENT_FLAG_USER_ACCESS;
else
event->hw.flags |= PERF_EVENT_FLAG_LEGACY;
}
static void pmu_sbi_event_mapped(struct perf_event *event, struct mm_struct *mm)
{
if (event->hw.flags & PERF_EVENT_FLAG_NO_USER_ACCESS)
return;
if (event->hw.flags & PERF_EVENT_FLAG_LEGACY) {
if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES &&
event->attr.config != PERF_COUNT_HW_INSTRUCTIONS) {
return;
}
}
/*
* The user mmapped the event to directly access it: this is where
* we determine based on sysctl_perf_user_access if we grant userspace
* the direct access to this event. That means that within the same
* task, some events may be directly accessible and some other may not,
* if the user changes the value of sysctl_perf_user_accesss in the
* meantime.
*/
event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT;
/*
* We must enable userspace access *before* advertising in the user page
* that it is possible to do so to avoid any race.
* And we must notify all cpus here because threads that currently run
* on other cpus will try to directly access the counter too without
* calling pmu_sbi_ctr_start.
*/
if (event->hw.flags & PERF_EVENT_FLAG_USER_ACCESS)
on_each_cpu_mask(mm_cpumask(mm),
pmu_sbi_set_scounteren, (void *)event, 1);
}
static void pmu_sbi_event_unmapped(struct perf_event *event, struct mm_struct *mm)
{
if (event->hw.flags & PERF_EVENT_FLAG_NO_USER_ACCESS)
return;
if (event->hw.flags & PERF_EVENT_FLAG_LEGACY) {
if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES &&
event->attr.config != PERF_COUNT_HW_INSTRUCTIONS) {
return;
}
}
/*
* Here we can directly remove user access since the user does not have
* access to the user page anymore so we avoid the racy window where the
* user could have read cap_user_rdpmc to true right before we disable
* it.
*/
event->hw.flags &= ~PERF_EVENT_FLAG_USER_READ_CNT;
if (event->hw.flags & PERF_EVENT_FLAG_USER_ACCESS)
on_each_cpu_mask(mm_cpumask(mm),
pmu_sbi_reset_scounteren, (void *)event, 1);
}
static void riscv_pmu_update_counter_access(void *info)
{
if (sysctl_perf_user_access == SYSCTL_LEGACY)
csr_write(CSR_SCOUNTEREN, 0x7);
else
csr_write(CSR_SCOUNTEREN, 0x2);
}
static int riscv_pmu_proc_user_access_handler(struct ctl_table *table,
int write, void *buffer,
size_t *lenp, loff_t *ppos)
{
int prev = sysctl_perf_user_access;
int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
/*
* Test against the previous value since we clear SCOUNTEREN when
* sysctl_perf_user_access is set to SYSCTL_USER_ACCESS, but we should
* not do that if that was already the case.
*/
if (ret || !write || prev == sysctl_perf_user_access)
return ret;
on_each_cpu(riscv_pmu_update_counter_access, NULL, 1);
return 0;
}
static struct ctl_table sbi_pmu_sysctl_table[] = {
{
.procname = "perf_user_access",
.data = &sysctl_perf_user_access,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = riscv_pmu_proc_user_access_handler,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_TWO,
},
{ }
};
static int pmu_sbi_device_probe(struct platform_device *pdev)
{
struct riscv_pmu *pmu = NULL;
int ret = -ENODEV;
int num_counters;
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;
}
/* It is possible to get from SBI more than max number of counters */
if (num_counters > RISCV_MAX_COUNTERS) {
num_counters = RISCV_MAX_COUNTERS;
pr_info("SBI returned more than maximum number of counters. Limiting the number of counters to %d\n", num_counters);
}
/* cache all the information about counters now */
if (pmu_sbi_get_ctrinfo(num_counters, &cmask))
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->pmu.attr_groups = riscv_pmu_attr_groups;
pmu->cmask = cmask;
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;
pmu->event_init = pmu_sbi_event_init;
pmu->event_mapped = pmu_sbi_event_mapped;
pmu->event_unmapped = pmu_sbi_event_unmapped;
pmu->csr_index = pmu_sbi_csr_index;
ret = cpuhp_state_add_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node);
if (ret)
return ret;
ret = riscv_pm_pmu_register(pmu);
if (ret)
goto out_unregister;
ret = perf_pmu_register(&pmu->pmu, "cpu", PERF_TYPE_RAW);
if (ret)
goto out_unregister;
register_sysctl("kernel", sbi_pmu_sysctl_table);
return 0;
out_unregister:
riscv_pmu_destroy(pmu);
out_free:
kfree(pmu);
return ret;
}
static struct platform_driver pmu_sbi_driver = {
.probe = pmu_sbi_device_probe,
.driver = {
.name = RISCV_PMU_SBI_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)) {
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_SBI_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)