From 55ee5e67a59a1b6f388d7a1c7b24022145f47a3e Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Thu, 10 Jun 2021 10:01:05 +0800 Subject: iommu/vt-d: Add common code for dmar latency performance monitors The execution time of some operations is very performance critical, such as cache invalidation and PRQ processing time. This adds some common code to monitor the execution time range of those operations. The interfaces include enabling/disabling, checking status, updating sampling data and providing a common string format for users. Signed-off-by: Fenghua Yu Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20210520031531.712333-1-baolu.lu@linux.intel.com Link: https://lore.kernel.org/r/20210610020115.1637656-14-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/intel/perf.c | 166 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 166 insertions(+) create mode 100644 drivers/iommu/intel/perf.c (limited to 'drivers/iommu/intel/perf.c') diff --git a/drivers/iommu/intel/perf.c b/drivers/iommu/intel/perf.c new file mode 100644 index 000000000000..faaa96dda437 --- /dev/null +++ b/drivers/iommu/intel/perf.c @@ -0,0 +1,166 @@ +// SPDX-License-Identifier: GPL-2.0 +/** + * perf.c - performance monitor + * + * Copyright (C) 2021 Intel Corporation + * + * Author: Lu Baolu + * Fenghua Yu + */ + +#include +#include + +#include "perf.h" + +static DEFINE_SPINLOCK(latency_lock); + +bool dmar_latency_enabled(struct intel_iommu *iommu, enum latency_type type) +{ + struct latency_statistic *lstat = iommu->perf_statistic; + + return lstat && lstat[type].enabled; +} + +int dmar_latency_enable(struct intel_iommu *iommu, enum latency_type type) +{ + struct latency_statistic *lstat; + unsigned long flags; + int ret = -EBUSY; + + if (dmar_latency_enabled(iommu, type)) + return 0; + + spin_lock_irqsave(&latency_lock, flags); + if (!iommu->perf_statistic) { + iommu->perf_statistic = kzalloc(sizeof(*lstat) * DMAR_LATENCY_NUM, + GFP_ATOMIC); + if (!iommu->perf_statistic) { + ret = -ENOMEM; + goto unlock_out; + } + } + + lstat = iommu->perf_statistic; + + if (!lstat[type].enabled) { + lstat[type].enabled = true; + lstat[type].counter[COUNTS_MIN] = UINT_MAX; + ret = 0; + } +unlock_out: + spin_unlock_irqrestore(&latency_lock, flags); + + return ret; +} + +void dmar_latency_disable(struct intel_iommu *iommu, enum latency_type type) +{ + struct latency_statistic *lstat = iommu->perf_statistic; + unsigned long flags; + + if (!dmar_latency_enabled(iommu, type)) + return; + + spin_lock_irqsave(&latency_lock, flags); + memset(&lstat[type], 0, sizeof(*lstat) * DMAR_LATENCY_NUM); + spin_unlock_irqrestore(&latency_lock, flags); +} + +void dmar_latency_update(struct intel_iommu *iommu, enum latency_type type, u64 latency) +{ + struct latency_statistic *lstat = iommu->perf_statistic; + unsigned long flags; + u64 min, max; + + if (!dmar_latency_enabled(iommu, type)) + return; + + spin_lock_irqsave(&latency_lock, flags); + if (latency < 100) + lstat[type].counter[COUNTS_10e2]++; + else if (latency < 1000) + lstat[type].counter[COUNTS_10e3]++; + else if (latency < 10000) + lstat[type].counter[COUNTS_10e4]++; + else if (latency < 100000) + lstat[type].counter[COUNTS_10e5]++; + else if (latency < 1000000) + lstat[type].counter[COUNTS_10e6]++; + else if (latency < 10000000) + lstat[type].counter[COUNTS_10e7]++; + else + lstat[type].counter[COUNTS_10e8_plus]++; + + min = lstat[type].counter[COUNTS_MIN]; + max = lstat[type].counter[COUNTS_MAX]; + lstat[type].counter[COUNTS_MIN] = min_t(u64, min, latency); + lstat[type].counter[COUNTS_MAX] = max_t(u64, max, latency); + lstat[type].counter[COUNTS_SUM] += latency; + lstat[type].samples++; + spin_unlock_irqrestore(&latency_lock, flags); +} + +static char *latency_counter_names[] = { + " <0.1us", + " 0.1us-1us", " 1us-10us", " 10us-100us", + " 100us-1ms", " 1ms-10ms", " >=10ms", + " min(us)", " max(us)", " average(us)" +}; + +static char *latency_type_names[] = { + " inv_iotlb", " inv_devtlb", " inv_iec", + " svm_prq" +}; + +int dmar_latency_snapshot(struct intel_iommu *iommu, char *str, size_t size) +{ + struct latency_statistic *lstat = iommu->perf_statistic; + unsigned long flags; + int bytes = 0, i, j; + + memset(str, 0, size); + + for (i = 0; i < COUNTS_NUM; i++) + bytes += snprintf(str + bytes, size - bytes, + "%s", latency_counter_names[i]); + + spin_lock_irqsave(&latency_lock, flags); + for (i = 0; i < DMAR_LATENCY_NUM; i++) { + if (!dmar_latency_enabled(iommu, i)) + continue; + + bytes += snprintf(str + bytes, size - bytes, + "\n%s", latency_type_names[i]); + + for (j = 0; j < COUNTS_NUM; j++) { + u64 val = lstat[i].counter[j]; + + switch (j) { + case COUNTS_MIN: + if (val == UINT_MAX) + val = 0; + else + val /= 1000; + break; + case COUNTS_MAX: + val /= 1000; + break; + case COUNTS_SUM: + if (lstat[i].samples) + val /= (lstat[i].samples * 1000); + else + val = 0; + break; + default: + break; + } + + bytes += snprintf(str + bytes, size - bytes, + "%12lld", val); + } + } + spin_unlock_irqrestore(&latency_lock, flags); + + return bytes; +} -- cgit v1.2.3