DEBUG: iommu/arm-smmu-v3: Add SVA trace events

maillist inclusion
category: feature
bugzilla: 51855
CVE: NA

Reference: https://jpbrucker.net/git/linux/commit/?h=sva/2021-03-01&id=870541b34bfa7ba8d5846fcb3246e533e7492e20

---------------------------------------------

It's useful when debugging to have some trace events for SVA object
allocation and freeing.
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: NLijun Fang <fanglijun3@huawei.com>
Reviewed-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c

@@ -8,6 +8,8 @@
 #include <linux/mmu_notifier.h>
 #include <linux/slab.h>
 
+#include <trace/events/smmu.h>
+
 #include "arm-smmu-v3.h"
 #include "../../iommu-sva-lib.h"
 #include "../../io-pgtable-arm.h"
@@ -191,6 +193,7 @@ static void arm_smmu_mm_invalidate_range(struct mmu_notifier *mn,
 		arm_smmu_tlb_inv_range_asid(start, size, smmu_mn->cd->asid,
 					    PAGE_SIZE, false, smmu_domain);
 	arm_smmu_atc_inv_domain(smmu_domain, mm->pasid, start, size);
+	trace_smmu_mm_invalidate(mm->pasid, start, end);
 }
 
 static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
@@ -240,6 +243,7 @@ arm_smmu_mmu_notifier_get(struct arm_smmu_domain *smmu_domain,
 	list_for_each_entry(smmu_mn, &smmu_domain->mmu_notifiers, list) {
 		if (smmu_mn->mn.mm == mm) {
 			refcount_inc(&smmu_mn->refs);
+			trace_smmu_mn_get(mm->pasid);
 			return smmu_mn;
 		}
 	}
@@ -270,6 +274,7 @@ arm_smmu_mmu_notifier_get(struct arm_smmu_domain *smmu_domain,
 		goto err_put_notifier;
 
 	list_add(&smmu_mn->list, &smmu_domain->mmu_notifiers);
+	trace_smmu_mn_alloc(mm->pasid);
 	return smmu_mn;
 
 err_put_notifier:
@@ -286,8 +291,10 @@ static void arm_smmu_mmu_notifier_put(struct arm_smmu_mmu_notifier *smmu_mn)
 	struct arm_smmu_ctx_desc *cd = smmu_mn->cd;
 	struct arm_smmu_domain *smmu_domain = smmu_mn->domain;
 
-	if (!refcount_dec_and_test(&smmu_mn->refs))
+	if (!refcount_dec_and_test(&smmu_mn->refs)) {
+		trace_smmu_mn_put(mm->pasid);
 		return;
+	}
 
 	list_del(&smmu_mn->list);
 	arm_smmu_write_ctx_desc(smmu_domain, mm->pasid, NULL);
@@ -303,6 +310,7 @@ static void arm_smmu_mmu_notifier_put(struct arm_smmu_mmu_notifier *smmu_mn)
 
 	/* Frees smmu_mn */
 	mmu_notifier_put(&smmu_mn->mn);
+	trace_smmu_mn_free(mm->pasid);
 	arm_smmu_free_shared_cd(cd);
 }
 
@@ -321,6 +329,7 @@ __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm)
 	/* If bind() was already called for this {dev, mm} pair, reuse it. */
 	list_for_each_entry(bond, &master->bonds, list) {
 		if (bond->mm == mm) {
+			trace_smmu_bind_get(dev, mm->pasid);
 			refcount_inc(&bond->refs);
 			return &bond->sva;
 		}
@@ -346,6 +355,7 @@ __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm)
 	}
 
 	list_add(&bond->list, &master->bonds);
+	trace_smmu_bind_alloc(dev, mm->pasid);
 	return &bond->sva;
 
 err_free_pasid:
@@ -390,10 +400,13 @@ void arm_smmu_sva_unbind(struct iommu_sva *handle)
 
 	mutex_lock(&sva_lock);
 	if (refcount_dec_and_test(&bond->refs)) {
+		trace_smmu_unbind_free(handle->dev, bond->mm->pasid);
 		list_del(&bond->list);
 		arm_smmu_mmu_notifier_put(bond->smmu_mn);
 		iommu_sva_free_pasid(bond->mm);
 		kfree(bond);
+	} else {
+		trace_smmu_unbind_put(handle->dev, bond->mm->pasid);
 	}
 	mutex_unlock(&sva_lock);
 }

drivers/iommu/iommu-traces.c

@@ -11,6 +11,7 @@
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/iommu.h>
+#include <trace/events/smmu.h>
 
 /* iommu_group_event */
 EXPORT_TRACEPOINT_SYMBOL_GPL(add_device_to_group);
@@ -26,3 +27,15 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(unmap);
 
 /* iommu_error */
 EXPORT_TRACEPOINT_SYMBOL_GPL(io_page_fault);
+
+/* Arm SMMUv3 traces */
+EXPORT_TRACEPOINT_SYMBOL_GPL(smmu_bind_alloc);
+EXPORT_TRACEPOINT_SYMBOL_GPL(smmu_bind_get);
+EXPORT_TRACEPOINT_SYMBOL_GPL(smmu_unbind_put);
+EXPORT_TRACEPOINT_SYMBOL_GPL(smmu_unbind_free);
+EXPORT_TRACEPOINT_SYMBOL_GPL(smmu_mm_release);
+EXPORT_TRACEPOINT_SYMBOL_GPL(smmu_mm_invalidate);
+EXPORT_TRACEPOINT_SYMBOL_GPL(smmu_mn_alloc);
+EXPORT_TRACEPOINT_SYMBOL_GPL(smmu_mn_free);
+EXPORT_TRACEPOINT_SYMBOL_GPL(smmu_mn_get);
+EXPORT_TRACEPOINT_SYMBOL_GPL(smmu_mn_put);

include/trace/events/smmu.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Arm SMMUv3 trace points
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM smmu
+
+#if !defined(_TRACE_SMMU_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SMMU_H
+
+#include <linux/tracepoint.h>
+
+struct device;
+
+DECLARE_EVENT_CLASS(smmu_bond,
+		    TP_PROTO(struct device *dev, unsigned int pasid),
+		    TP_ARGS(dev, pasid),
+		    TP_STRUCT__entry(
+			__string(dev, dev_name(dev))
+			__field(int, pasid)
+		    ),
+		    TP_fast_assign(
+			__assign_str(dev, dev_name(dev));
+			__entry->pasid = pasid;
+		    ),
+		    TP_printk("dev=%s pasid=%d", __get_str(dev), __entry->pasid)
+);
+
+DEFINE_EVENT(smmu_bond, smmu_bind_alloc,
+	     TP_PROTO(struct device *dev, unsigned int pasid),
+	     TP_ARGS(dev, pasid));
+
+DEFINE_EVENT(smmu_bond, smmu_bind_get,
+	     TP_PROTO(struct device *dev, unsigned int pasid),
+	     TP_ARGS(dev, pasid));
+
+DEFINE_EVENT(smmu_bond, smmu_unbind_put,
+	     TP_PROTO(struct device *dev, unsigned int pasid),
+	     TP_ARGS(dev, pasid));
+
+DEFINE_EVENT(smmu_bond, smmu_unbind_free,
+	     TP_PROTO(struct device *dev, unsigned int pasid),
+	     TP_ARGS(dev, pasid));
+
+TRACE_EVENT(smmu_mm_release,
+	    TP_PROTO(unsigned int pasid),
+	    TP_ARGS(pasid),
+	    TP_STRUCT__entry(__field(int, pasid)),
+	    TP_fast_assign(__entry->pasid = pasid;),
+	    TP_printk("pasid=%d", __entry->pasid)
+);
+
+TRACE_EVENT(smmu_mm_invalidate,
+	    TP_PROTO(unsigned int pasid,
+		     unsigned long start, unsigned long end),
+	    TP_ARGS(pasid, start, end),
+	    TP_STRUCT__entry(
+			__field(int, pasid)
+			__field(unsigned long, start)
+			__field(unsigned long, end)
+		    ),
+	    TP_fast_assign(
+			   __entry->pasid = pasid;
+			   __entry->start = start;
+			   __entry->end = end;
+			  ),
+	    TP_printk("pasid=%d start=0x%lx end=0x%lx",
+		      __entry->pasid, __entry->start,
+		      __entry->end)
+)
+
+DECLARE_EVENT_CLASS(smmu_mn,
+		    TP_PROTO(unsigned int pasid),
+		    TP_ARGS(pasid),
+		    TP_STRUCT__entry(__field(int, pasid)),
+		    TP_fast_assign(__entry->pasid = pasid;),
+		    TP_printk("pasid=%d", __entry->pasid)
+);
+
+DEFINE_EVENT(smmu_mn, smmu_mn_alloc, TP_PROTO(unsigned int pasid), TP_ARGS(pasid));
+DEFINE_EVENT(smmu_mn, smmu_mn_free, TP_PROTO(unsigned int pasid), TP_ARGS(pasid));
+DEFINE_EVENT(smmu_mn, smmu_mn_get, TP_PROTO(unsigned int pasid), TP_ARGS(pasid));
+DEFINE_EVENT(smmu_mn, smmu_mn_put, TP_PROTO(unsigned int pasid), TP_ARGS(pasid));
+
+
+#endif /* _TRACE_SMMU_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>