Iommuv3 debug

arch/arm64/configs/altra_5.10_defconfig

@@ -1597,3 +1597,5 @@ CONFIG_FAULT_INJECTION_STACKTRACE_FILTER=y
 CONFIG_ATOMIC64_SELFTEST=y
 CONFIG_ASYNC_RAID6_TEST=m
 CONFIG_TEST_KSTRTOX=y
+CONFIG_IOMMU_DEBUGFS=y
+CONFIG_ARM_SMMU_V3_DEBUGFS=y

drivers/iommu/Kconfig

@@ -318,6 +318,17 @@ config ARM_SMMU_V3_SVA
 	  Say Y here if your system supports SVA extensions such as PCIe PASID
 	  and PRI.
 
+config ARM_SMMU_V3_DEBUGFS
+	bool "Export ARM SMMUv3 internals in Debugfs"
+	depends on ARM_SMMU_V3 && IOMMU_DEBUGFS
+	help
+	  DO NOT ENABLE THIS OPTION UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!
+
+	  Expose ARM SMMUv3 internals in Debugfs.
+
+	  This option is -NOT- intended for production environments, and should
+	  only be enabled for debugging ARM SMMUv3.
+
 config S390_IOMMU
 	def_bool y if S390 && PCI
 	depends on S390 && PCI

drivers/iommu/arm/arm-smmu-v3/Makefile

@@ -3,3 +3,4 @@ obj-$(CONFIG_ARM_SMMU_V3) += arm_smmu_v3.o
 arm_smmu_v3-objs-y += arm-smmu-v3.o
 arm_smmu_v3-objs-$(CONFIG_ARM_SMMU_V3_SVA) += arm-smmu-v3-sva.o
 arm_smmu_v3-objs := $(arm_smmu_v3-objs-y)
+obj-$(CONFIG_ARM_SMMU_V3_DEBUGFS) += debugfs.o

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

@@ -955,8 +955,7 @@ static void arm_smmu_write_cd_l1_desc(__le64 *dst,
 	WRITE_ONCE(*dst, cpu_to_le64(val));
 }
 
-static __le64 *arm_smmu_get_cd_ptr(struct arm_smmu_domain *smmu_domain,
-				   u32 ssid)
+__le64 *arm_smmu_get_cd_ptr(struct arm_smmu_domain *smmu_domain, u32 ssid)
 {
 	__le64 *l1ptr;
 	unsigned int idx;
@@ -981,6 +980,7 @@ static __le64 *arm_smmu_get_cd_ptr(struct arm_smmu_domain *smmu_domain,
 	idx = ssid & (CTXDESC_L2_ENTRIES - 1);
 	return l1_desc->l2ptr + idx * CTXDESC_CD_DWORDS;
 }
+EXPORT_SYMBOL_GPL(arm_smmu_get_cd_ptr);
 
 int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain, int ssid,
 			    struct arm_smmu_ctx_desc *cd)
@@ -2012,7 +2012,7 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain,
 	return 0;
 }
 
-static __le64 *arm_smmu_get_step_for_sid(struct arm_smmu_device *smmu, u32 sid)
+__le64 *arm_smmu_get_step_for_sid(struct arm_smmu_device *smmu, u32 sid)
 {
 	__le64 *step;
 	struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
@@ -2033,6 +2033,7 @@ static __le64 *arm_smmu_get_step_for_sid(struct arm_smmu_device *smmu, u32 sid)
 
 	return step;
 }
+EXPORT_SYMBOL_GPL(arm_smmu_get_step_for_sid);
 
 static void arm_smmu_install_ste_for_dev(struct arm_smmu_master *master)
 {
@@ -3595,6 +3596,8 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	arm_smmu_debugfs_init();
+
 	return arm_smmu_set_bus_ops(&arm_smmu_ops);
 }
 
@@ -3603,6 +3606,7 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
 	struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
 
 	arm_smmu_set_bus_ops(NULL);
+	arm_smmu_debugfs_uninit();
 	iommu_device_unregister(&smmu->iommu);
 	iommu_device_sysfs_remove(&smmu->iommu);
 	arm_smmu_device_disable(smmu);

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h

@@ -687,6 +687,8 @@ int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain, int ssid,
 			    struct arm_smmu_ctx_desc *cd);
 void arm_smmu_tlb_inv_asid(struct arm_smmu_device *smmu, u16 asid);
 bool arm_smmu_free_asid(struct arm_smmu_ctx_desc *cd);
+__le64 *arm_smmu_get_cd_ptr(struct arm_smmu_domain *smmu_domain, u32 ssid);
+__le64 *arm_smmu_get_step_for_sid(struct arm_smmu_device *smmu, u32 sid);
 
 #ifdef CONFIG_ARM_SMMU_V3_SVA
 bool arm_smmu_sva_supported(struct arm_smmu_device *smmu);
@@ -720,4 +722,12 @@ static inline int arm_smmu_master_disable_sva(struct arm_smmu_master *master)
 	return -ENODEV;
 }
 #endif /* CONFIG_ARM_SMMU_V3_SVA */
+
+#ifdef CONFIG_ARM_SMMU_V3_DEBUGFS
+void arm_smmu_debugfs_init(void);
+void arm_smmu_debugfs_uninit(void);
+#else
+static inline void arm_smmu_debugfs_init(void) {}
+static inline void arm_smmu_debugfs_uninit(void) {}
+#endif /* CONFIG_ARM_SMMU_V3_DEBUGFS */
 #endif /* _ARM_SMMU_V3_H */