[RFC PATCH 2/8] iommu/arm-smmu-v3: Add SMMU implementation

[Xueqi Zhang]

Mediatek has its own implementation for wrapper interrupts and
power management.So add SMMU implementation when smmu device probe.

Signed-off-by: Xueqi Zhang <xueqi.zhang at mediatek.com>
---
 drivers/iommu/arm/Kconfig                        |  7 +++++++
 drivers/iommu/arm/arm-smmu-v3/Makefile           |  3 ++-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-impl.c | 16 ++++++++++++++++
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-mediatek.c | 13 +++++++++++++
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c      |  3 +++
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h      |  4 ++++
 6 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-impl.c
 create mode 100644 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-mediatek.c

diff --git a/drivers/iommu/arm/Kconfig b/drivers/iommu/arm/Kconfig
index ef42bbe07dbe..a7f98fd0f2bf 100644
--- a/drivers/iommu/arm/Kconfig
+++ b/drivers/iommu/arm/Kconfig
@@ -88,6 +88,13 @@ config ARM_SMMU_V3
 	  the ARM SMMUv3 architecture.
 
 if ARM_SMMU_V3
+config ARM_SMMU_V3_MEDIATEK
+	bool "ARM Ltd. System MMU Version 3 (SMMUv3) MediaTek Support"
+	depends on ARM_SMMU_V3 && ARCH_MEDIATEK
+	help
+	  When running on a MediaTek platform that has the custom variant
+	  of the ARM SMMUv3, this needs to be built into the SMMU driver.
+
 config ARM_SMMU_V3_SVA
 	bool "Shared Virtual Addressing support for the ARM SMMUv3"
 	select IOMMU_SVA
diff --git a/drivers/iommu/arm/arm-smmu-v3/Makefile b/drivers/iommu/arm/arm-smmu-v3/Makefile
index 493a659cc66b..0670065d6e9a 100644
--- a/drivers/iommu/arm/arm-smmu-v3/Makefile
+++ b/drivers/iommu/arm/arm-smmu-v3/Makefile
@@ -1,7 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_ARM_SMMU_V3) += arm_smmu_v3.o
-arm_smmu_v3-y := arm-smmu-v3.o
+arm_smmu_v3-y := arm-smmu-v3.o arm-smmu-v3-impl.o
 arm_smmu_v3-$(CONFIG_ARM_SMMU_V3_IOMMUFD) += arm-smmu-v3-iommufd.o
+arm_smmu_v3-$(CONFIG_ARM_SMMU_V3_MEDIATEK) += arm-smmu-v3-mediatek.o
 arm_smmu_v3-$(CONFIG_ARM_SMMU_V3_SVA) += arm-smmu-v3-sva.o
 arm_smmu_v3-$(CONFIG_TEGRA241_CMDQV) += tegra241-cmdqv.o
 
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-impl.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-impl.c
new file mode 100644
index 000000000000..d39587b965ef
--- /dev/null
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-impl.c
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2025 MediaTek Inc.
+ * Author: Ning li <ning.li at mediatek.com>
+ * Author: Xueqi Zhang <xueqi.zhang at mediatek.com>
+ */
+
+#include "arm-smmu-v3.h"
+
+struct arm_smmu_device *arm_smmu_v3_impl_init(struct arm_smmu_device *smmu)
+{
+#if IS_ENABLED(CONFIG_ARM_SMMU_V3_MEDIATEK)
+	smmu = arm_smmu_v3_impl_mtk_init(smmu);
+#endif
+	return smmu;
+}
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-mediatek.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-mediatek.c
new file mode 100644
index 000000000000..381268968185
--- /dev/null
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-mediatek.c
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2025 MediaTek Inc.
+ * Author: Ning li <ning.li at mediatek.com>
+ * Author: Xueqi Zhang <xueqi.zhang at mediatek.com>
+ */
+
+#include "arm-smmu-v3.h"
+
+struct arm_smmu_device *arm_smmu_v3_impl_mtk_init(struct arm_smmu_device *smmu)
+{
+	return NULL;
+}
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 10cc6dc26b7b..d36124a6bb54 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -4754,6 +4754,9 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	}
 	ioaddr = res->start;
 
+	smmu = arm_smmu_v3_impl_init(smmu);
+	if (IS_ERR(smmu))
+		return PTR_ERR(smmu);
 	/*
 	 * Don't map the IMPLEMENTATION DEFINED regions, since they may contain
 	 * the PMCG registers which are reserved by the PMU driver.
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index ea41d790463e..99eeb6143c49 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -998,6 +998,10 @@ int arm_smmu_cmdq_issue_cmdlist(struct arm_smmu_device *smmu,
 				struct arm_smmu_cmdq *cmdq, u64 *cmds, int n,
 				bool sync);
 
+struct arm_smmu_device *arm_smmu_v3_impl_init(struct arm_smmu_device *smmu);
+#if IS_ENABLED(CONFIG_ARM_SMMU_V3_MEDIATEK)
+struct arm_smmu_device *arm_smmu_v3_impl_mtk_init(struct arm_smmu_device *smmu);
+#endif
 #ifdef CONFIG_ARM_SMMU_V3_SVA
 bool arm_smmu_sva_supported(struct arm_smmu_device *smmu);
 void arm_smmu_sva_notifier_synchronize(void);
-- 
2.46.0