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-rw-r--r--drivers/iommu/intel/Kconfig3
-rw-r--r--drivers/iommu/intel/Makefile1
-rw-r--r--drivers/iommu/intel/perf.c166
-rw-r--r--drivers/iommu/intel/perf.h73
-rw-r--r--include/linux/intel-iommu.h1
5 files changed, 244 insertions, 0 deletions
diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig
index a37bd54c5b90..59be5447b775 100644
--- a/drivers/iommu/intel/Kconfig
+++ b/drivers/iommu/intel/Kconfig
@@ -3,6 +3,9 @@
config DMAR_TABLE
bool
+config DMAR_PERF
+ bool
+
config INTEL_IOMMU
bool "Support for Intel IOMMU using DMA Remapping Devices"
depends on PCI_MSI && ACPI && (X86 || IA64)
diff --git a/drivers/iommu/intel/Makefile b/drivers/iommu/intel/Makefile
index ae236ec7d219..fa0dae16441c 100644
--- a/drivers/iommu/intel/Makefile
+++ b/drivers/iommu/intel/Makefile
@@ -2,6 +2,7 @@
obj-$(CONFIG_DMAR_TABLE) += dmar.o
obj-$(CONFIG_INTEL_IOMMU) += iommu.o pasid.o
obj-$(CONFIG_DMAR_TABLE) += trace.o cap_audit.o
+obj-$(CONFIG_DMAR_PERF) += perf.o
obj-$(CONFIG_INTEL_IOMMU_DEBUGFS) += debugfs.o
obj-$(CONFIG_INTEL_IOMMU_SVM) += svm.o
obj-$(CONFIG_IRQ_REMAP) += irq_remapping.o
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 <baolu.lu@linux.intel.com>
+ * Fenghua Yu <fenghua.yu@intel.com>
+ */
+
+#include <linux/spinlock.h>
+#include <linux/intel-iommu.h>
+
+#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;
+}
diff --git a/drivers/iommu/intel/perf.h b/drivers/iommu/intel/perf.h
new file mode 100644
index 000000000000..fd6db8049d1a
--- /dev/null
+++ b/drivers/iommu/intel/perf.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * perf.h - performance monitor header
+ *
+ * Copyright (C) 2021 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ */
+
+enum latency_type {
+ DMAR_LATENCY_INV_IOTLB = 0,
+ DMAR_LATENCY_INV_DEVTLB,
+ DMAR_LATENCY_INV_IEC,
+ DMAR_LATENCY_PRQ,
+ DMAR_LATENCY_NUM
+};
+
+enum latency_count {
+ COUNTS_10e2 = 0, /* < 0.1us */
+ COUNTS_10e3, /* 0.1us ~ 1us */
+ COUNTS_10e4, /* 1us ~ 10us */
+ COUNTS_10e5, /* 10us ~ 100us */
+ COUNTS_10e6, /* 100us ~ 1ms */
+ COUNTS_10e7, /* 1ms ~ 10ms */
+ COUNTS_10e8_plus, /* 10ms and plus*/
+ COUNTS_MIN,
+ COUNTS_MAX,
+ COUNTS_SUM,
+ COUNTS_NUM
+};
+
+struct latency_statistic {
+ bool enabled;
+ u64 counter[COUNTS_NUM];
+ u64 samples;
+};
+
+#ifdef CONFIG_DMAR_PERF
+int dmar_latency_enable(struct intel_iommu *iommu, enum latency_type type);
+void dmar_latency_disable(struct intel_iommu *iommu, enum latency_type type);
+bool dmar_latency_enabled(struct intel_iommu *iommu, enum latency_type type);
+void dmar_latency_update(struct intel_iommu *iommu, enum latency_type type,
+ u64 latency);
+int dmar_latency_snapshot(struct intel_iommu *iommu, char *str, size_t size);
+#else
+static inline int
+dmar_latency_enable(struct intel_iommu *iommu, enum latency_type type)
+{
+ return -EINVAL;
+}
+
+static inline void
+dmar_latency_disable(struct intel_iommu *iommu, enum latency_type type)
+{
+}
+
+static inline bool
+dmar_latency_enabled(struct intel_iommu *iommu, enum latency_type type)
+{
+ return false;
+}
+
+static inline void
+dmar_latency_update(struct intel_iommu *iommu, enum latency_type type, u64 latency)
+{
+}
+
+static inline int
+dmar_latency_snapshot(struct intel_iommu *iommu, char *str, size_t size)
+{
+ return 0;
+}
+#endif /* CONFIG_DMAR_PERF */
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 98b04fa9373e..f5cf31dd7280 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -621,6 +621,7 @@ struct intel_iommu {
u32 flags; /* Software defined flags */
struct dmar_drhd_unit *drhd;
+ void *perf_statistic;
};
/* Per subdevice private data */
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-31 13:36:05 +0300