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From: Tomasz Jeznach <tjeznach@rivosinc.com>
To: Joerg Roedel <joro@8bytes.org>,
	Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Anup Patel <apatel@ventanamicro.com>,
	Sunil V L <sunilvl@ventanamicro.com>,
	Nick Kossifidis <mick@ics.forth.gr>,
	Sebastien Boeuf <seb@rivosinc.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	devicetree@vger.kernel.org,
	iommu@lists.linux.dev,
	linux-riscv@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	linux@rivosinc.com,
	Tomasz Jeznach <tjeznach@rivosinc.com>,
	Lu Baolu <baolu.lu@linux.intel.com>
Subject: [PATCH v6 2/7] iommu/riscv: Add RISC-V IOMMU platform device driver
Date: Fri, 24 May 2024 12:34:42 -0700
Message-Id: <7dcd9a154625704cbf9adc4b4ac07ca0b9753b31.1716578450.git.tjeznach@rivosinc.com>
In-Reply-To: <cover.1716578450.git.tjeznach@rivosinc.com>
References: <cover.1716578450.git.tjeznach@rivosinc.com>
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Introduce platform device driver for implementation of RISC-V IOMMU
architected hardware.

Hardware interface definition located in file iommu-bits.h is based on
ratified RISC-V IOMMU Architecture Specification version 1.0.0.

This patch implements platform device initialization, early check and
configuration of the IOMMU interfaces and enables global pass-through
address translation mode (iommu_mode == BARE), without registering
hardware instance in the IOMMU subsystem.

Link: https://github.com/riscv-non-isa/riscv-iommu
Co-developed-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
Co-developed-by: Sebastien Boeuf <seb@rivosinc.com>
Signed-off-by: Sebastien Boeuf <seb@rivosinc.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Tomasz Jeznach <tjeznach@rivosinc.com>
---
 MAINTAINERS                          |   1 +
 drivers/iommu/Kconfig                |   1 +
 drivers/iommu/Makefile               |   2 +-
 drivers/iommu/riscv/Kconfig          |  15 +
 drivers/iommu/riscv/Makefile         |   2 +
 drivers/iommu/riscv/iommu-bits.h     | 707 +++++++++++++++++++++++++++
 drivers/iommu/riscv/iommu-platform.c |  92 ++++
 drivers/iommu/riscv/iommu.c          |  99 ++++
 drivers/iommu/riscv/iommu.h          |  62 +++
 9 files changed, 980 insertions(+), 1 deletion(-)
 create mode 100644 drivers/iommu/riscv/Kconfig
 create mode 100644 drivers/iommu/riscv/Makefile
 create mode 100644 drivers/iommu/riscv/iommu-bits.h
 create mode 100644 drivers/iommu/riscv/iommu-platform.c
 create mode 100644 drivers/iommu/riscv/iommu.c
 create mode 100644 drivers/iommu/riscv/iommu.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 1ce589eb9c15..2269aead257c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19271,6 +19271,7 @@ L:	iommu@lists.linux.dev
 L:	linux-riscv@lists.infradead.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/iommu/riscv,iommu.yaml
+F:	drivers/iommu/riscv/
 
 RISC-V MICROCHIP FPGA SUPPORT
 M:	Conor Dooley <conor.dooley@microchip.com>
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index c04584be3089..9359f07fe671 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -195,6 +195,7 @@ config MSM_IOMMU
 source "drivers/iommu/amd/Kconfig"
 source "drivers/iommu/intel/Kconfig"
 source "drivers/iommu/iommufd/Kconfig"
+source "drivers/iommu/riscv/Kconfig"
 
 config IRQ_REMAP
 	bool "Support for Interrupt Remapping"
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 542760d963ec..5e5a83c6c2aa 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
-obj-y += amd/ intel/ arm/ iommufd/
+obj-y += amd/ intel/ arm/ iommufd/ riscv/
 obj-$(CONFIG_IOMMU_API) += iommu.o
 obj-$(CONFIG_IOMMU_API) += iommu-traces.o
 obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o
diff --git a/drivers/iommu/riscv/Kconfig b/drivers/iommu/riscv/Kconfig
new file mode 100644
index 000000000000..5dcc5c45aa50
--- /dev/null
+++ b/drivers/iommu/riscv/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# RISC-V IOMMU support
+
+config RISCV_IOMMU
+	bool "RISC-V IOMMU Support"
+	depends on RISCV && 64BIT
+	default y
+	select IOMMU_API
+	help
+	  Support for implementations of the RISC-V IOMMU architecture that
+	  complements the RISC-V MMU capabilities, providing similar address
+	  translation and protection functions for accesses from I/O devices.
+
+	  Say Y here if your SoC includes an IOMMU device implementing
+	  the RISC-V IOMMU architecture.
diff --git a/drivers/iommu/riscv/Makefile b/drivers/iommu/riscv/Makefile
new file mode 100644
index 000000000000..e4c189de58d3
--- /dev/null
+++ b/drivers/iommu/riscv/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_RISCV_IOMMU) += iommu.o iommu-platform.o
diff --git a/drivers/iommu/riscv/iommu-bits.h b/drivers/iommu/riscv/iommu-bits.h
new file mode 100644
index 000000000000..48f795a0cd10
--- /dev/null
+++ b/drivers/iommu/riscv/iommu-bits.h
@@ -0,0 +1,707 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright © 2022-2024 Rivos Inc.
+ * Copyright © 2023 FORTH-ICS/CARV
+ * Copyright © 2023 RISC-V IOMMU Task Group
+ *
+ * RISC-V IOMMU - Register Layout and Data Structures.
+ *
+ * Based on the 'RISC-V IOMMU Architecture Specification', Version 1.0
+ * Published at  https://github.com/riscv-non-isa/riscv-iommu
+ *
+ */
+
+#ifndef _RISCV_IOMMU_BITS_H_
+#define _RISCV_IOMMU_BITS_H_
+
+#include <linux/types.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+
+/*
+ * Chapter 5: Memory Mapped register interface
+ */
+
+/* Common field positions */
+#define RISCV_IOMMU_PPN_FIELD		GENMASK_ULL(53, 10)
+#define RISCV_IOMMU_QUEUE_LOGSZ_FIELD	GENMASK_ULL(4, 0)
+#define RISCV_IOMMU_QUEUE_INDEX_FIELD	GENMASK_ULL(31, 0)
+#define RISCV_IOMMU_QUEUE_ENABLE	BIT(0)
+#define RISCV_IOMMU_QUEUE_INTR_ENABLE	BIT(1)
+#define RISCV_IOMMU_QUEUE_MEM_FAULT	BIT(8)
+#define RISCV_IOMMU_QUEUE_OVERFLOW	BIT(9)
+#define RISCV_IOMMU_QUEUE_ACTIVE	BIT(16)
+#define RISCV_IOMMU_QUEUE_BUSY		BIT(17)
+
+#define RISCV_IOMMU_ATP_PPN_FIELD	GENMASK_ULL(43, 0)
+#define RISCV_IOMMU_ATP_MODE_FIELD	GENMASK_ULL(63, 60)
+
+/* 5.3 IOMMU Capabilities (64bits) */
+#define RISCV_IOMMU_REG_CAP		0x0000
+#define RISCV_IOMMU_CAP_VERSION		GENMASK_ULL(7, 0)
+#define RISCV_IOMMU_CAP_S_SV32		BIT_ULL(8)
+#define RISCV_IOMMU_CAP_S_SV39		BIT_ULL(9)
+#define RISCV_IOMMU_CAP_S_SV48		BIT_ULL(10)
+#define RISCV_IOMMU_CAP_S_SV57		BIT_ULL(11)
+#define RISCV_IOMMU_CAP_SVPBMT		BIT_ULL(15)
+#define RISCV_IOMMU_CAP_G_SV32		BIT_ULL(16)
+#define RISCV_IOMMU_CAP_G_SV39		BIT_ULL(17)
+#define RISCV_IOMMU_CAP_G_SV48		BIT_ULL(18)
+#define RISCV_IOMMU_CAP_G_SV57		BIT_ULL(19)
+#define RISCV_IOMMU_CAP_AMO_MRIF	BIT_ULL(21)
+#define RISCV_IOMMU_CAP_MSI_FLAT	BIT_ULL(22)
+#define RISCV_IOMMU_CAP_MSI_MRIF	BIT_ULL(23)
+#define RISCV_IOMMU_CAP_AMO_HWAD	BIT_ULL(24)
+#define RISCV_IOMMU_CAP_ATS		BIT_ULL(25)
+#define RISCV_IOMMU_CAP_T2GPA		BIT_ULL(26)
+#define RISCV_IOMMU_CAP_END		BIT_ULL(27)
+#define RISCV_IOMMU_CAP_IGS		GENMASK_ULL(29, 28)
+#define RISCV_IOMMU_CAP_HPM		BIT_ULL(30)
+#define RISCV_IOMMU_CAP_DBG		BIT_ULL(31)
+#define RISCV_IOMMU_CAP_PAS		GENMASK_ULL(37, 32)
+#define RISCV_IOMMU_CAP_PD8		BIT_ULL(38)
+#define RISCV_IOMMU_CAP_PD17		BIT_ULL(39)
+#define RISCV_IOMMU_CAP_PD20		BIT_ULL(40)
+
+#define RISCV_IOMMU_CAP_VERSION_VER_MASK	0xF0
+#define RISCV_IOMMU_CAP_VERSION_REV_MASK	0x0F
+
+/**
+ * enum riscv_iommu_igs_settings - Interrupt Generation Support Settings
+ * @RISCV_IOMMU_CAP_IGS_MSI: I/O MMU supports only MSI generation
+ * @RISCV_IOMMU_CAP_IGS_WSI: I/O MMU supports only Wired-Signaled interrupt
+ * @RISCV_IOMMU_CAP_IGS_BOTH: I/O MMU supports both MSI and WSI generation
+ * @RISCV_IOMMU_CAP_IGS_RSRV: Reserved for standard use
+ */
+enum riscv_iommu_igs_settings {
+	RISCV_IOMMU_CAP_IGS_MSI = 0,
+	RISCV_IOMMU_CAP_IGS_WSI = 1,
+	RISCV_IOMMU_CAP_IGS_BOTH = 2,
+	RISCV_IOMMU_CAP_IGS_RSRV = 3
+};
+
+/* 5.4 Features control register (32bits) */
+#define RISCV_IOMMU_REG_FCTL		0x0008
+#define RISCV_IOMMU_FCTL_BE		BIT(0)
+#define RISCV_IOMMU_FCTL_WSI		BIT(1)
+#define RISCV_IOMMU_FCTL_GXL		BIT(2)
+
+/* 5.5 Device-directory-table pointer (64bits) */
+#define RISCV_IOMMU_REG_DDTP		0x0010
+#define RISCV_IOMMU_DDTP_MODE		GENMASK_ULL(3, 0)
+#define RISCV_IOMMU_DDTP_BUSY		BIT_ULL(4)
+#define RISCV_IOMMU_DDTP_PPN		RISCV_IOMMU_PPN_FIELD
+
+/**
+ * enum riscv_iommu_ddtp_modes - I/O MMU translation modes
+ * @RISCV_IOMMU_DDTP_MODE_OFF: No inbound transactions allowed
+ * @RISCV_IOMMU_DDTP_MODE_BARE: Pass-through mode
+ * @RISCV_IOMMU_DDTP_MODE_1LVL: One-level DDT
+ * @RISCV_IOMMU_DDTP_MODE_2LVL: Two-level DDT
+ * @RISCV_IOMMU_DDTP_MODE_3LVL: Three-level DDT
+ * @RISCV_IOMMU_DDTP_MODE_MAX: Max value allowed by specification
+ */
+enum riscv_iommu_ddtp_modes {
+	RISCV_IOMMU_DDTP_MODE_OFF = 0,
+	RISCV_IOMMU_DDTP_MODE_BARE = 1,
+	RISCV_IOMMU_DDTP_MODE_1LVL = 2,
+	RISCV_IOMMU_DDTP_MODE_2LVL = 3,
+	RISCV_IOMMU_DDTP_MODE_3LVL = 4,
+	RISCV_IOMMU_DDTP_MODE_MAX = 4
+};
+
+/* 5.6 Command Queue Base (64bits) */
+#define RISCV_IOMMU_REG_CQB		0x0018
+#define RISCV_IOMMU_CQB_ENTRIES		RISCV_IOMMU_QUEUE_LOGSZ_FIELD
+#define RISCV_IOMMU_CQB_PPN		RISCV_IOMMU_PPN_FIELD
+
+/* 5.7 Command Queue head (32bits) */
+#define RISCV_IOMMU_REG_CQH		0x0020
+#define RISCV_IOMMU_CQH_INDEX		RISCV_IOMMU_QUEUE_INDEX_FIELD
+
+/* 5.8 Command Queue tail (32bits) */
+#define RISCV_IOMMU_REG_CQT		0x0024
+#define RISCV_IOMMU_CQT_INDEX		RISCV_IOMMU_QUEUE_INDEX_FIELD
+
+/* 5.9 Fault Queue Base (64bits) */
+#define RISCV_IOMMU_REG_FQB		0x0028
+#define RISCV_IOMMU_FQB_ENTRIES		RISCV_IOMMU_QUEUE_LOGSZ_FIELD
+#define RISCV_IOMMU_FQB_PPN		RISCV_IOMMU_PPN_FIELD
+
+/* 5.10 Fault Queue Head (32bits) */
+#define RISCV_IOMMU_REG_FQH		0x0030
+#define RISCV_IOMMU_FQH_INDEX		RISCV_IOMMU_QUEUE_INDEX_FIELD
+
+/* 5.11 Fault Queue tail (32bits) */
+#define RISCV_IOMMU_REG_FQT		0x0034
+#define RISCV_IOMMU_FQT_INDEX		RISCV_IOMMU_QUEUE_INDEX_FIELD
+
+/* 5.12 Page Request Queue base (64bits) */
+#define RISCV_IOMMU_REG_PQB		0x0038
+#define RISCV_IOMMU_PQB_ENTRIES		RISCV_IOMMU_QUEUE_LOGSZ_FIELD
+#define RISCV_IOMMU_PQB_PPN		RISCV_IOMMU_PPN_FIELD
+
+/* 5.13 Page Request Queue head (32bits) */
+#define RISCV_IOMMU_REG_PQH		0x0040
+#define RISCV_IOMMU_PQH_INDEX		RISCV_IOMMU_QUEUE_INDEX_FIELD
+
+/* 5.14 Page Request Queue tail (32bits) */
+#define RISCV_IOMMU_REG_PQT		0x0044
+#define RISCV_IOMMU_PQT_INDEX_MASK	RISCV_IOMMU_QUEUE_INDEX_FIELD
+
+/* 5.15 Command Queue CSR (32bits) */
+#define RISCV_IOMMU_REG_CQCSR		0x0048
+#define RISCV_IOMMU_CQCSR_CQEN		RISCV_IOMMU_QUEUE_ENABLE
+#define RISCV_IOMMU_CQCSR_CIE		RISCV_IOMMU_QUEUE_INTR_ENABLE
+#define RISCV_IOMMU_CQCSR_CQMF		RISCV_IOMMU_QUEUE_MEM_FAULT
+#define RISCV_IOMMU_CQCSR_CMD_TO	BIT(9)
+#define RISCV_IOMMU_CQCSR_CMD_ILL	BIT(10)
+#define RISCV_IOMMU_CQCSR_FENCE_W_IP	BIT(11)
+#define RISCV_IOMMU_CQCSR_CQON		RISCV_IOMMU_QUEUE_ACTIVE
+#define RISCV_IOMMU_CQCSR_BUSY		RISCV_IOMMU_QUEUE_BUSY
+
+/* 5.16 Fault Queue CSR (32bits) */
+#define RISCV_IOMMU_REG_FQCSR		0x004C
+#define RISCV_IOMMU_FQCSR_FQEN		RISCV_IOMMU_QUEUE_ENABLE
+#define RISCV_IOMMU_FQCSR_FIE		RISCV_IOMMU_QUEUE_INTR_ENABLE
+#define RISCV_IOMMU_FQCSR_FQMF		RISCV_IOMMU_QUEUE_MEM_FAULT
+#define RISCV_IOMMU_FQCSR_FQOF		RISCV_IOMMU_QUEUE_OVERFLOW
+#define RISCV_IOMMU_FQCSR_FQON		RISCV_IOMMU_QUEUE_ACTIVE
+#define RISCV_IOMMU_FQCSR_BUSY		RISCV_IOMMU_QUEUE_BUSY
+
+/* 5.17 Page Request Queue CSR (32bits) */
+#define RISCV_IOMMU_REG_PQCSR		0x0050
+#define RISCV_IOMMU_PQCSR_PQEN		RISCV_IOMMU_QUEUE_ENABLE
+#define RISCV_IOMMU_PQCSR_PIE		RISCV_IOMMU_QUEUE_INTR_ENABLE
+#define RISCV_IOMMU_PQCSR_PQMF		RISCV_IOMMU_QUEUE_MEM_FAULT
+#define RISCV_IOMMU_PQCSR_PQOF		RISCV_IOMMU_QUEUE_OVERFLOW
+#define RISCV_IOMMU_PQCSR_PQON		RISCV_IOMMU_QUEUE_ACTIVE
+#define RISCV_IOMMU_PQCSR_BUSY		RISCV_IOMMU_QUEUE_BUSY
+
+/* 5.18 Interrupt Pending Status (32bits) */
+#define RISCV_IOMMU_REG_IPSR		0x0054
+
+#define RISCV_IOMMU_INTR_CQ		0
+#define RISCV_IOMMU_INTR_FQ		1
+#define RISCV_IOMMU_INTR_PM		2
+#define RISCV_IOMMU_INTR_PQ		3
+#define RISCV_IOMMU_INTR_COUNT		4
+
+#define RISCV_IOMMU_IPSR_CIP		BIT(RISCV_IOMMU_INTR_CQ)
+#define RISCV_IOMMU_IPSR_FIP		BIT(RISCV_IOMMU_INTR_FQ)
+#define RISCV_IOMMU_IPSR_PMIP		BIT(RISCV_IOMMU_INTR_PM)
+#define RISCV_IOMMU_IPSR_PIP		BIT(RISCV_IOMMU_INTR_PQ)
+
+/* 5.19 Performance monitoring counter overflow status (32bits) */
+#define RISCV_IOMMU_REG_IOCOUNTOVF	0x0058
+#define RISCV_IOMMU_IOCOUNTOVF_CY	BIT(0)
+#define RISCV_IOMMU_IOCOUNTOVF_HPM	GENMASK_ULL(31, 1)
+
+/* 5.20 Performance monitoring counter inhibits (32bits) */
+#define RISCV_IOMMU_REG_IOCOUNTINH	0x005C
+#define RISCV_IOMMU_IOCOUNTINH_CY	BIT(0)
+#define RISCV_IOMMU_IOCOUNTINH_HPM	GENMASK(31, 1)
+
+/* 5.21 Performance monitoring cycles counter (64bits) */
+#define RISCV_IOMMU_REG_IOHPMCYCLES     0x0060
+#define RISCV_IOMMU_IOHPMCYCLES_COUNTER	GENMASK_ULL(62, 0)
+#define RISCV_IOMMU_IOHPMCYCLES_OVF	BIT_ULL(63)
+
+/* 5.22 Performance monitoring event counters (31 * 64bits) */
+#define RISCV_IOMMU_REG_IOHPMCTR_BASE	0x0068
+#define RISCV_IOMMU_REG_IOHPMCTR(_n)	(RISCV_IOMMU_REG_IOHPMCTR_BASE + ((_n) * 0x8))
+
+/* 5.23 Performance monitoring event selectors (31 * 64bits) */
+#define RISCV_IOMMU_REG_IOHPMEVT_BASE	0x0160
+#define RISCV_IOMMU_REG_IOHPMEVT(_n)	(RISCV_IOMMU_REG_IOHPMEVT_BASE + ((_n) * 0x8))
+#define RISCV_IOMMU_IOHPMEVT_CNT	31
+#define RISCV_IOMMU_IOHPMEVT_EVENT_ID	GENMASK_ULL(14, 0)
+#define RISCV_IOMMU_IOHPMEVT_DMASK	BIT_ULL(15)
+#define RISCV_IOMMU_IOHPMEVT_PID_PSCID	GENMASK_ULL(35, 16)
+#define RISCV_IOMMU_IOHPMEVT_DID_GSCID	GENMASK_ULL(59, 36)
+#define RISCV_IOMMU_IOHPMEVT_PV_PSCV	BIT_ULL(60)
+#define RISCV_IOMMU_IOHPMEVT_DV_GSCV	BIT_ULL(61)
+#define RISCV_IOMMU_IOHPMEVT_IDT	BIT_ULL(62)
+#define RISCV_IOMMU_IOHPMEVT_OF		BIT_ULL(63)
+
+/**
+ * enum riscv_iommu_hpmevent_id - Performance-monitoring event identifier
+ *
+ * @RISCV_IOMMU_HPMEVENT_INVALID: Invalid event, do not count
+ * @RISCV_IOMMU_HPMEVENT_URQ: Untranslated requests
+ * @RISCV_IOMMU_HPMEVENT_TRQ: Translated requests
+ * @RISCV_IOMMU_HPMEVENT_ATS_RQ: ATS translation requests
+ * @RISCV_IOMMU_HPMEVENT_TLB_MISS: TLB misses
+ * @RISCV_IOMMU_HPMEVENT_DD_WALK: Device directory walks
+ * @RISCV_IOMMU_HPMEVENT_PD_WALK: Process directory walks
+ * @RISCV_IOMMU_HPMEVENT_S_VS_WALKS: S/VS-Stage page table walks
+ * @RISCV_IOMMU_HPMEVENT_G_WALKS: G-Stage page table walks
+ * @RISCV_IOMMU_HPMEVENT_MAX: Value to denote maximum Event IDs
+ */
+enum riscv_iommu_hpmevent_id {
+	RISCV_IOMMU_HPMEVENT_INVALID    = 0,
+	RISCV_IOMMU_HPMEVENT_URQ        = 1,
+	RISCV_IOMMU_HPMEVENT_TRQ        = 2,
+	RISCV_IOMMU_HPMEVENT_ATS_RQ     = 3,
+	RISCV_IOMMU_HPMEVENT_TLB_MISS   = 4,
+	RISCV_IOMMU_HPMEVENT_DD_WALK    = 5,
+	RISCV_IOMMU_HPMEVENT_PD_WALK    = 6,
+	RISCV_IOMMU_HPMEVENT_S_VS_WALKS = 7,
+	RISCV_IOMMU_HPMEVENT_G_WALKS    = 8,
+	RISCV_IOMMU_HPMEVENT_MAX        = 9
+};
+
+/* 5.24 Translation request IOVA (64bits) */
+#define RISCV_IOMMU_REG_TR_REQ_IOVA     0x0258
+#define RISCV_IOMMU_TR_REQ_IOVA_VPN	GENMASK_ULL(63, 12)
+
+/* 5.25 Translation request control (64bits) */
+#define RISCV_IOMMU_REG_TR_REQ_CTL	0x0260
+#define RISCV_IOMMU_TR_REQ_CTL_GO_BUSY	BIT_ULL(0)
+#define RISCV_IOMMU_TR_REQ_CTL_PRIV	BIT_ULL(1)
+#define RISCV_IOMMU_TR_REQ_CTL_EXE	BIT_ULL(2)
+#define RISCV_IOMMU_TR_REQ_CTL_NW	BIT_ULL(3)
+#define RISCV_IOMMU_TR_REQ_CTL_PID	GENMASK_ULL(31, 12)
+#define RISCV_IOMMU_TR_REQ_CTL_PV	BIT_ULL(32)
+#define RISCV_IOMMU_TR_REQ_CTL_DID	GENMASK_ULL(63, 40)
+
+/* 5.26 Translation request response (64bits) */
+#define RISCV_IOMMU_REG_TR_RESPONSE	0x0268
+#define RISCV_IOMMU_TR_RESPONSE_FAULT	BIT_ULL(0)
+#define RISCV_IOMMU_TR_RESPONSE_PBMT	GENMASK_ULL(8, 7)
+#define RISCV_IOMMU_TR_RESPONSE_SZ	BIT_ULL(9)
+#define RISCV_IOMMU_TR_RESPONSE_PPN	RISCV_IOMMU_PPN_FIELD
+
+/* 5.27 Interrupt cause to vector (64bits) */
+#define RISCV_IOMMU_REG_ICVEC		0x02F8
+#define RISCV_IOMMU_ICVEC_CIV		GENMASK_ULL(3, 0)
+#define RISCV_IOMMU_ICVEC_FIV		GENMASK_ULL(7, 4)
+#define RISCV_IOMMU_ICVEC_PMIV		GENMASK_ULL(11, 8)
+#define RISCV_IOMMU_ICVEC_PIV		GENMASK_ULL(15, 12)
+
+/* 5.28 MSI Configuration table (32 * 64bits) */
+#define RISCV_IOMMU_REG_MSI_CONFIG	0x0300
+#define RISCV_IOMMU_REG_MSI_ADDR(_n)	(RISCV_IOMMU_REG_MSI_CONFIG + ((_n) * 0x10))
+#define RISCV_IOMMU_MSI_ADDR		GENMASK_ULL(55, 2)
+#define RISCV_IOMMU_REG_MSI_DATA(_n)	(RISCV_IOMMU_REG_MSI_CONFIG + ((_n) * 0x10) + 0x08)
+#define RISCV_IOMMU_MSI_DATA		GENMASK_ULL(31, 0)
+#define RISCV_IOMMU_REG_MSI_VEC_CTL(_n)	(RISCV_IOMMU_REG_MSI_CONFIG + ((_n) * 0x10) + 0x0C)
+#define RISCV_IOMMU_MSI_VEC_CTL_M	BIT_ULL(0)
+
+#define RISCV_IOMMU_REG_SIZE	0x1000
+
+/*
+ * Chapter 2: Data structures
+ */
+
+/*
+ * Device Directory Table macros for non-leaf nodes
+ */
+#define RISCV_IOMMU_DDTE_VALID	BIT_ULL(0)
+#define RISCV_IOMMU_DDTE_PPN	RISCV_IOMMU_PPN_FIELD
+
+/**
+ * struct riscv_iommu_dc - Device Context
+ * @tc: Translation Control
+ * @iohgatp: I/O Hypervisor guest address translation and protection
+ *	     (Second stage context)
+ * @ta: Translation Attributes
+ * @fsc: First stage context
+ * @msiptp: MSI page table pointer
+ * @msi_addr_mask: MSI address mask
+ * @msi_addr_pattern: MSI address pattern
+ * @_reserved: Reserved for future use, padding
+ *
+ * This structure is used for leaf nodes on the Device Directory Table,
+ * in case RISCV_IOMMU_CAP_MSI_FLAT is not set, the bottom 4 fields are
+ * not present and are skipped with pointer arithmetic to avoid
+ * casting, check out riscv_iommu_get_dc().
+ * See section 2.1 for more details
+ */
+struct riscv_iommu_dc {
+	u64 tc;
+	u64 iohgatp;
+	u64 ta;
+	u64 fsc;
+	u64 msiptp;
+	u64 msi_addr_mask;
+	u64 msi_addr_pattern;
+	u64 _reserved;
+};
+
+/* Translation control fields */
+#define RISCV_IOMMU_DC_TC_V		BIT_ULL(0)
+#define RISCV_IOMMU_DC_TC_EN_ATS	BIT_ULL(1)
+#define RISCV_IOMMU_DC_TC_EN_PRI	BIT_ULL(2)
+#define RISCV_IOMMU_DC_TC_T2GPA		BIT_ULL(3)
+#define RISCV_IOMMU_DC_TC_DTF		BIT_ULL(4)
+#define RISCV_IOMMU_DC_TC_PDTV		BIT_ULL(5)
+#define RISCV_IOMMU_DC_TC_PRPR		BIT_ULL(6)
+#define RISCV_IOMMU_DC_TC_GADE		BIT_ULL(7)
+#define RISCV_IOMMU_DC_TC_SADE		BIT_ULL(8)
+#define RISCV_IOMMU_DC_TC_DPE		BIT_ULL(9)
+#define RISCV_IOMMU_DC_TC_SBE		BIT_ULL(10)
+#define RISCV_IOMMU_DC_TC_SXL		BIT_ULL(11)
+
+/* Second-stage (aka G-stage) context fields */
+#define RISCV_IOMMU_DC_IOHGATP_PPN	RISCV_IOMMU_ATP_PPN_FIELD
+#define RISCV_IOMMU_DC_IOHGATP_GSCID	GENMASK_ULL(59, 44)
+#define RISCV_IOMMU_DC_IOHGATP_MODE	RISCV_IOMMU_ATP_MODE_FIELD
+
+/**
+ * enum riscv_iommu_dc_iohgatp_modes - Guest address translation/protection modes
+ * @RISCV_IOMMU_DC_IOHGATP_MODE_BARE: No translation/protection
+ * @RISCV_IOMMU_DC_IOHGATP_MODE_SV32X4: Sv32x4 (2-bit extension of Sv32), when fctl.GXL == 1
+ * @RISCV_IOMMU_DC_IOHGATP_MODE_SV39X4: Sv39x4 (2-bit extension of Sv39), when fctl.GXL == 0
+ * @RISCV_IOMMU_DC_IOHGATP_MODE_SV48X4: Sv48x4 (2-bit extension of Sv48), when fctl.GXL == 0
+ * @RISCV_IOMMU_DC_IOHGATP_MODE_SV57X4: Sv57x4 (2-bit extension of Sv57), when fctl.GXL == 0
+ */
+enum riscv_iommu_dc_iohgatp_modes {
+	RISCV_IOMMU_DC_IOHGATP_MODE_BARE = 0,
+	RISCV_IOMMU_DC_IOHGATP_MODE_SV32X4 = 8,
+	RISCV_IOMMU_DC_IOHGATP_MODE_SV39X4 = 8,
+	RISCV_IOMMU_DC_IOHGATP_MODE_SV48X4 = 9,
+	RISCV_IOMMU_DC_IOHGATP_MODE_SV57X4 = 10
+};
+
+/* Translation attributes fields */
+#define RISCV_IOMMU_DC_TA_PSCID		GENMASK_ULL(31, 12)
+
+/* First-stage context fields */
+#define RISCV_IOMMU_DC_FSC_PPN		RISCV_IOMMU_ATP_PPN_FIELD
+#define RISCV_IOMMU_DC_FSC_MODE		RISCV_IOMMU_ATP_MODE_FIELD
+
+/**
+ * enum riscv_iommu_dc_fsc_atp_modes - First stage address translation/protection modes
+ * @RISCV_IOMMU_DC_FSC_MODE_BARE: No translation/protection
+ * @RISCV_IOMMU_DC_FSC_IOSATP_MODE_SV32: Sv32, when dc.tc.SXL == 1
+ * @RISCV_IOMMU_DC_FSC_IOSATP_MODE_SV39: Sv39, when dc.tc.SXL == 0
+ * @RISCV_IOMMU_DC_FSC_IOSATP_MODE_SV48: Sv48, when dc.tc.SXL == 0
+ * @RISCV_IOMMU_DC_FSC_IOSATP_MODE_SV57: Sv57, when dc.tc.SXL == 0
+ * @RISCV_IOMMU_DC_FSC_PDTP_MODE_PD8: 1lvl PDT, 8bit process ids
+ * @RISCV_IOMMU_DC_FSC_PDTP_MODE_PD17: 2lvl PDT, 17bit process ids
+ * @RISCV_IOMMU_DC_FSC_PDTP_MODE_PD20: 3lvl PDT, 20bit process ids
+ *
+ * FSC holds IOSATP when RISCV_IOMMU_DC_TC_PDTV is 0 and PDTP otherwise.
+ * IOSATP controls the first stage address translation (same as the satp register on
+ * the RISC-V MMU), and PDTP holds the process directory table, used to select a
+ * first stage page table based on a process id (for devices that support multiple
+ * process ids).
+ */
+enum riscv_iommu_dc_fsc_atp_modes {
+	RISCV_IOMMU_DC_FSC_MODE_BARE = 0,
+	RISCV_IOMMU_DC_FSC_IOSATP_MODE_SV32 = 8,
+	RISCV_IOMMU_DC_FSC_IOSATP_MODE_SV39 = 8,
+	RISCV_IOMMU_DC_FSC_IOSATP_MODE_SV48 = 9,
+	RISCV_IOMMU_DC_FSC_IOSATP_MODE_SV57 = 10,
+	RISCV_IOMMU_DC_FSC_PDTP_MODE_PD8 = 1,
+	RISCV_IOMMU_DC_FSC_PDTP_MODE_PD17 = 2,
+	RISCV_IOMMU_DC_FSC_PDTP_MODE_PD20 = 3
+};
+
+/* MSI page table pointer */
+#define RISCV_IOMMU_DC_MSIPTP_PPN	RISCV_IOMMU_ATP_PPN_FIELD
+#define RISCV_IOMMU_DC_MSIPTP_MODE	RISCV_IOMMU_ATP_MODE_FIELD
+#define RISCV_IOMMU_DC_MSIPTP_MODE_OFF	0
+#define RISCV_IOMMU_DC_MSIPTP_MODE_FLAT	1
+
+/* MSI address mask */
+#define RISCV_IOMMU_DC_MSI_ADDR_MASK	GENMASK_ULL(51, 0)
+
+/* MSI address pattern */
+#define RISCV_IOMMU_DC_MSI_PATTERN	GENMASK_ULL(51, 0)
+
+/**
+ * struct riscv_iommu_pc - Process Context
+ * @ta: Translation Attributes
+ * @fsc: First stage context
+ *
+ * This structure is used for leaf nodes on the Process Directory Table
+ * See section 2.3 for more details
+ */
+struct riscv_iommu_pc {
+	u64 ta;
+	u64 fsc;
+};
+
+/* Translation attributes fields */
+#define RISCV_IOMMU_PC_TA_V	BIT_ULL(0)
+#define RISCV_IOMMU_PC_TA_ENS	BIT_ULL(1)
+#define RISCV_IOMMU_PC_TA_SUM	BIT_ULL(2)
+#define RISCV_IOMMU_PC_TA_PSCID	GENMASK_ULL(31, 12)
+
+/* First stage context fields */
+#define RISCV_IOMMU_PC_FSC_PPN	RISCV_IOMMU_ATP_PPN_FIELD
+#define RISCV_IOMMU_PC_FSC_MODE	RISCV_IOMMU_ATP_MODE_FIELD
+
+/*
+ * Chapter 3: In-memory queue interface
+ */
+
+/**
+ * struct riscv_iommu_command - Generic I/O MMU command structure
+ * @dword0: Includes the opcode and the function identifier
+ * @dword1: Opcode specific data
+ *
+ * The commands are interpreted as two 64bit fields, where the first
+ * 7bits of the first field are the opcode which also defines the
+ * command's format, followed by a 3bit field that specifies the
+ * function invoked by that command, and the rest is opcode-specific.
+ * This is a generic struct which will be populated differently
+ * according to each command. For more infos on the commands and
+ * the command queue check section 3.1.
+ */
+struct riscv_iommu_command {
+	u64 dword0;
+	u64 dword1;
+};
+
+/* Fields on dword0, common for all commands */
+#define RISCV_IOMMU_CMD_OPCODE	GENMASK_ULL(6, 0)
+#define	RISCV_IOMMU_CMD_FUNC	GENMASK_ULL(9, 7)
+
+/* 3.1.1 I/O MMU Page-table cache invalidation */
+/* Fields on dword0 */
+#define RISCV_IOMMU_CMD_IOTINVAL_OPCODE		1
+#define RISCV_IOMMU_CMD_IOTINVAL_FUNC_VMA	0
+#define RISCV_IOMMU_CMD_IOTINVAL_FUNC_GVMA	1
+#define RISCV_IOMMU_CMD_IOTINVAL_AV		BIT_ULL(10)
+#define RISCV_IOMMU_CMD_IOTINVAL_PSCID		GENMASK_ULL(31, 12)
+#define RISCV_IOMMU_CMD_IOTINVAL_PSCV		BIT_ULL(32)
+#define RISCV_IOMMU_CMD_IOTINVAL_GV		BIT_ULL(33)
+#define RISCV_IOMMU_CMD_IOTINVAL_GSCID		GENMASK_ULL(59, 44)
+/* dword1[61:10] is the 4K-aligned page address */
+#define RISCV_IOMMU_CMD_IOTINVAL_ADDR		GENMASK_ULL(61, 10)
+
+/* 3.1.2 I/O MMU Command Queue Fences */
+/* Fields on dword0 */
+#define RISCV_IOMMU_CMD_IOFENCE_OPCODE		2
+#define RISCV_IOMMU_CMD_IOFENCE_FUNC_C		0
+#define RISCV_IOMMU_CMD_IOFENCE_AV		BIT_ULL(10)
+#define RISCV_IOMMU_CMD_IOFENCE_WSI		BIT_ULL(11)
+#define RISCV_IOMMU_CMD_IOFENCE_PR		BIT_ULL(12)
+#define RISCV_IOMMU_CMD_IOFENCE_PW		BIT_ULL(13)
+#define RISCV_IOMMU_CMD_IOFENCE_DATA		GENMASK_ULL(63, 32)
+/* dword1 is the address, word-size aligned and shifted to the right by two bits. */
+
+/* 3.1.3 I/O MMU Directory cache invalidation */
+/* Fields on dword0 */
+#define RISCV_IOMMU_CMD_IODIR_OPCODE		3
+#define RISCV_IOMMU_CMD_IODIR_FUNC_INVAL_DDT	0
+#define RISCV_IOMMU_CMD_IODIR_FUNC_INVAL_PDT	1
+#define RISCV_IOMMU_CMD_IODIR_PID		GENMASK_ULL(31, 12)
+#define RISCV_IOMMU_CMD_IODIR_DV		BIT_ULL(33)
+#define RISCV_IOMMU_CMD_IODIR_DID		GENMASK_ULL(63, 40)
+/* dword1 is reserved for standard use */
+
+/* 3.1.4 I/O MMU PCIe ATS */
+/* Fields on dword0 */
+#define RISCV_IOMMU_CMD_ATS_OPCODE		4
+#define RISCV_IOMMU_CMD_ATS_FUNC_INVAL		0
+#define RISCV_IOMMU_CMD_ATS_FUNC_PRGR		1
+#define RISCV_IOMMU_CMD_ATS_PID			GENMASK_ULL(31, 12)
+#define RISCV_IOMMU_CMD_ATS_PV			BIT_ULL(32)
+#define RISCV_IOMMU_CMD_ATS_DSV			BIT_ULL(33)
+#define RISCV_IOMMU_CMD_ATS_RID			GENMASK_ULL(55, 40)
+#define RISCV_IOMMU_CMD_ATS_DSEG		GENMASK_ULL(63, 56)
+/* dword1 is the ATS payload, two different payload types for INVAL and PRGR */
+
+/* ATS.INVAL payload*/
+#define RISCV_IOMMU_CMD_ATS_INVAL_G		BIT_ULL(0)
+/* Bits 1 - 10 are zeroed */
+#define RISCV_IOMMU_CMD_ATS_INVAL_S		BIT_ULL(11)
+#define RISCV_IOMMU_CMD_ATS_INVAL_UADDR		GENMASK_ULL(63, 12)
+
+/* ATS.PRGR payload */
+/* Bits 0 - 31 are zeroed */
+#define RISCV_IOMMU_CMD_ATS_PRGR_PRG_INDEX	GENMASK_ULL(40, 32)
+/* Bits 41 - 43 are zeroed */
+#define RISCV_IOMMU_CMD_ATS_PRGR_RESP_CODE	GENMASK_ULL(47, 44)
+#define RISCV_IOMMU_CMD_ATS_PRGR_DST_ID		GENMASK_ULL(63, 48)
+
+/**
+ * struct riscv_iommu_fq_record - Fault/Event Queue Record
+ * @hdr: Header, includes fault/event cause, PID/DID, transaction type etc
+ * @_reserved: Low 32bits for custom use, high 32bits for standard use
+ * @iotval: Transaction-type/cause specific format
+ * @iotval2: Cause specific format
+ *
+ * The fault/event queue reports events and failures raised when
+ * processing transactions. Each record is a 32byte structure where
+ * the first dword has a fixed format for providing generic infos
+ * regarding the fault/event, and two more dwords are there for
+ * fault/event-specific information. For more details see section
+ * 3.2.
+ */
+struct riscv_iommu_fq_record {
+	u64 hdr;
+	u64 _reserved;
+	u64 iotval;
+	u64 iotval2;
+};
+
+/* Fields on header */
+#define RISCV_IOMMU_FQ_HDR_CAUSE	GENMASK_ULL(11, 0)
+#define RISCV_IOMMU_FQ_HDR_PID		GENMASK_ULL(31, 12)
+#define RISCV_IOMMU_FQ_HDR_PV		BIT_ULL(32)
+#define RISCV_IOMMU_FQ_HDR_PRIV		BIT_ULL(33)
+#define RISCV_IOMMU_FQ_HDR_TTYPE	GENMASK_ULL(39, 34)
+#define RISCV_IOMMU_FQ_HDR_DID		GENMASK_ULL(63, 40)
+
+/**
+ * enum riscv_iommu_fq_causes - Fault/event cause values
+ * @RISCV_IOMMU_FQ_CAUSE_INST_FAULT: Instruction access fault
+ * @RISCV_IOMMU_FQ_CAUSE_RD_ADDR_MISALIGNED: Read address misaligned
+ * @RISCV_IOMMU_FQ_CAUSE_RD_FAULT: Read load fault
+ * @RISCV_IOMMU_FQ_CAUSE_WR_ADDR_MISALIGNED: Write/AMO address misaligned
+ * @RISCV_IOMMU_FQ_CAUSE_WR_FAULT: Write/AMO access fault
+ * @RISCV_IOMMU_FQ_CAUSE_INST_FAULT_S: Instruction page fault
+ * @RISCV_IOMMU_FQ_CAUSE_RD_FAULT_S: Read page fault
+ * @RISCV_IOMMU_FQ_CAUSE_WR_FAULT_S: Write/AMO page fault
+ * @RISCV_IOMMU_FQ_CAUSE_INST_FAULT_VS: Instruction guest page fault
+ * @RISCV_IOMMU_FQ_CAUSE_RD_FAULT_VS: Read guest page fault
+ * @RISCV_IOMMU_FQ_CAUSE_WR_FAULT_VS: Write/AMO guest page fault
+ * @RISCV_IOMMU_FQ_CAUSE_DMA_DISABLED: All inbound transactions disallowed
+ * @RISCV_IOMMU_FQ_CAUSE_DDT_LOAD_FAULT: DDT entry load access fault
+ * @RISCV_IOMMU_FQ_CAUSE_DDT_INVALID: DDT entry invalid
+ * @RISCV_IOMMU_FQ_CAUSE_DDT_MISCONFIGURED: DDT entry misconfigured
+ * @RISCV_IOMMU_FQ_CAUSE_TTYPE_BLOCKED: Transaction type disallowed
+ * @RISCV_IOMMU_FQ_CAUSE_MSI_LOAD_FAULT: MSI PTE load access fault
+ * @RISCV_IOMMU_FQ_CAUSE_MSI_INVALID: MSI PTE invalid
+ * @RISCV_IOMMU_FQ_CAUSE_MSI_MISCONFIGURED: MSI PTE misconfigured
+ * @RISCV_IOMMU_FQ_CAUSE_MRIF_FAULT: MRIF access fault
+ * @RISCV_IOMMU_FQ_CAUSE_PDT_LOAD_FAULT: PDT entry load access fault
+ * @RISCV_IOMMU_FQ_CAUSE_PDT_INVALID: PDT entry invalid
+ * @RISCV_IOMMU_FQ_CAUSE_PDT_MISCONFIGURED: PDT entry misconfigured
+ * @RISCV_IOMMU_FQ_CAUSE_DDT_CORRUPTED: DDT data corruption
+ * @RISCV_IOMMU_FQ_CAUSE_PDT_CORRUPTED: PDT data corruption
+ * @RISCV_IOMMU_FQ_CAUSE_MSI_PT_CORRUPTED: MSI page table data corruption
+ * @RISCV_IOMMU_FQ_CAUSE_MRIF_CORRUIPTED: MRIF data corruption
+ * @RISCV_IOMMU_FQ_CAUSE_INTERNAL_DP_ERROR: Internal data path error
+ * @RISCV_IOMMU_FQ_CAUSE_MSI_WR_FAULT: IOMMU MSI write access fault
+ * @RISCV_IOMMU_FQ_CAUSE_PT_CORRUPTED: First/second stage page table data corruption
+ *
+ * Values are on table 11 of the spec, encodings 275 - 2047 are reserved for standard
+ * use, and 2048 - 4095 for custom use.
+ */
+enum riscv_iommu_fq_causes {
+	RISCV_IOMMU_FQ_CAUSE_INST_FAULT = 1,
+	RISCV_IOMMU_FQ_CAUSE_RD_ADDR_MISALIGNED = 4,
+	RISCV_IOMMU_FQ_CAUSE_RD_FAULT = 5,
+	RISCV_IOMMU_FQ_CAUSE_WR_ADDR_MISALIGNED = 6,
+	RISCV_IOMMU_FQ_CAUSE_WR_FAULT = 7,
+	RISCV_IOMMU_FQ_CAUSE_INST_FAULT_S = 12,
+	RISCV_IOMMU_FQ_CAUSE_RD_FAULT_S = 13,
+	RISCV_IOMMU_FQ_CAUSE_WR_FAULT_S = 15,
+	RISCV_IOMMU_FQ_CAUSE_INST_FAULT_VS = 20,
+	RISCV_IOMMU_FQ_CAUSE_RD_FAULT_VS = 21,
+	RISCV_IOMMU_FQ_CAUSE_WR_FAULT_VS = 23,
+	RISCV_IOMMU_FQ_CAUSE_DMA_DISABLED = 256,
+	RISCV_IOMMU_FQ_CAUSE_DDT_LOAD_FAULT = 257,
+	RISCV_IOMMU_FQ_CAUSE_DDT_INVALID = 258,
+	RISCV_IOMMU_FQ_CAUSE_DDT_MISCONFIGURED = 259,
+	RISCV_IOMMU_FQ_CAUSE_TTYPE_BLOCKED = 260,
+	RISCV_IOMMU_FQ_CAUSE_MSI_LOAD_FAULT = 261,
+	RISCV_IOMMU_FQ_CAUSE_MSI_INVALID = 262,
+	RISCV_IOMMU_FQ_CAUSE_MSI_MISCONFIGURED = 263,
+	RISCV_IOMMU_FQ_CAUSE_MRIF_FAULT = 264,
+	RISCV_IOMMU_FQ_CAUSE_PDT_LOAD_FAULT = 265,
+	RISCV_IOMMU_FQ_CAUSE_PDT_INVALID = 266,
+	RISCV_IOMMU_FQ_CAUSE_PDT_MISCONFIGURED = 267,
+	RISCV_IOMMU_FQ_CAUSE_DDT_CORRUPTED = 268,
+	RISCV_IOMMU_FQ_CAUSE_PDT_CORRUPTED = 269,
+	RISCV_IOMMU_FQ_CAUSE_MSI_PT_CORRUPTED = 270,
+	RISCV_IOMMU_FQ_CAUSE_MRIF_CORRUIPTED = 271,
+	RISCV_IOMMU_FQ_CAUSE_INTERNAL_DP_ERROR = 272,
+	RISCV_IOMMU_FQ_CAUSE_MSI_WR_FAULT = 273,
+	RISCV_IOMMU_FQ_CAUSE_PT_CORRUPTED = 274
+};
+
+/**
+ * enum riscv_iommu_fq_ttypes: Fault/event transaction types
+ * @RISCV_IOMMU_FQ_TTYPE_NONE: None. Fault not caused by an inbound transaction.
+ * @RISCV_IOMMU_FQ_TTYPE_UADDR_INST_FETCH: Instruction fetch from untranslated address
+ * @RISCV_IOMMU_FQ_TTYPE_UADDR_RD: Read from untranslated address
+ * @RISCV_IOMMU_FQ_TTYPE_UADDR_WR: Write/AMO to untranslated address
+ * @RISCV_IOMMU_FQ_TTYPE_TADDR_INST_FETCH: Instruction fetch from translated address
+ * @RISCV_IOMMU_FQ_TTYPE_TADDR_RD: Read from translated address
+ * @RISCV_IOMMU_FQ_TTYPE_TADDR_WR: Write/AMO to translated address
+ * @RISCV_IOMMU_FQ_TTYPE_PCIE_ATS_REQ: PCIe ATS translation request
+ * @RISCV_IOMMU_FW_TTYPE_PCIE_MSG_REQ: PCIe message request
+ *
+ * Values are on table 12 of the spec, type 4 and 10 - 31 are reserved for standard use
+ * and 31 - 63 for custom use.
+ */
+enum riscv_iommu_fq_ttypes {
+	RISCV_IOMMU_FQ_TTYPE_NONE = 0,
+	RISCV_IOMMU_FQ_TTYPE_UADDR_INST_FETCH = 1,
+	RISCV_IOMMU_FQ_TTYPE_UADDR_RD = 2,
+	RISCV_IOMMU_FQ_TTYPE_UADDR_WR = 3,
+	RISCV_IOMMU_FQ_TTYPE_TADDR_INST_FETCH = 5,
+	RISCV_IOMMU_FQ_TTYPE_TADDR_RD = 6,
+	RISCV_IOMMU_FQ_TTYPE_TADDR_WR = 7,
+	RISCV_IOMMU_FQ_TTYPE_PCIE_ATS_REQ = 8,
+	RISCV_IOMMU_FW_TTYPE_PCIE_MSG_REQ = 9,
+};
+
+/**
+ * struct riscv_iommu_pq_record - PCIe Page Request record
+ * @hdr: Header, includes PID, DID etc
+ * @payload: Holds the page address, request group and permission bits
+ *
+ * For more infos on the PCIe Page Request queue see chapter 3.3.
+ */
+struct riscv_iommu_pq_record {
+	u64 hdr;
+	u64 payload;
+};
+
+/* Header fields */
+#define RISCV_IOMMU_PREQ_HDR_PID	GENMASK_ULL(31, 12)
+#define RISCV_IOMMU_PREQ_HDR_PV		BIT_ULL(32)
+#define RISCV_IOMMU_PREQ_HDR_PRIV	BIT_ULL(33)
+#define RISCV_IOMMU_PREQ_HDR_EXEC	BIT_ULL(34)
+#define RISCV_IOMMU_PREQ_HDR_DID	GENMASK_ULL(63, 40)
+
+/* Payload fields */
+#define RISCV_IOMMU_PREQ_PAYLOAD_R	BIT_ULL(0)
+#define RISCV_IOMMU_PREQ_PAYLOAD_W	BIT_ULL(1)
+#define RISCV_IOMMU_PREQ_PAYLOAD_L	BIT_ULL(2)
+#define RISCV_IOMMU_PREQ_PAYLOAD_M	GENMASK_ULL(2, 0)	/* Mask of RWL for convenience */
+#define RISCV_IOMMU_PREQ_PRG_INDEX	GENMASK_ULL(11, 3)
+#define RISCV_IOMMU_PREQ_UADDR		GENMASK_ULL(63, 12)
+
+/**
+ * struct riscv_iommu_msi_pte - MSI Page Table Entry
+ * @pte: MSI PTE
+ * @mrif_info: Memory-resident interrupt file info
+ *
+ * The MSI Page Table is used for virtualizing MSIs, so that when
+ * a device sends an MSI to a guest, the IOMMU can reroute it
+ * by translating the MSI address, either to a guest interrupt file
+ * or a memory resident interrupt file (MRIF). Note that this page table
+ * is an array of MSI PTEs, not a multi-level pt, each entry
+ * is a leaf entry. For more infos check out the AIA spec, chapter 9.5.
+ *
+ * Also in basic mode the mrif_info field is ignored by the IOMMU and can
+ * be used by software, any other reserved fields on pte must be zeroed-out
+ * by software.
+ */
+struct riscv_iommu_msi_pte {
+	u64 pte;
+	u64 mrif_info;
+};
+
+/* Fields on pte */
+#define RISCV_IOMMU_MSI_PTE_V		BIT_ULL(0)
+#define RISCV_IOMMU_MSI_PTE_M		GENMASK_ULL(2, 1)
+#define RISCV_IOMMU_MSI_PTE_MRIF_ADDR	GENMASK_ULL(53, 7)	/* When M == 1 (MRIF mode) */
+#define RISCV_IOMMU_MSI_PTE_PPN		RISCV_IOMMU_PPN_FIELD	/* When M == 3 (basic mode) */
+#define RISCV_IOMMU_MSI_PTE_C		BIT_ULL(63)
+
+/* Fields on mrif_info */
+#define RISCV_IOMMU_MSI_MRIF_NID	GENMASK_ULL(9, 0)
+#define RISCV_IOMMU_MSI_MRIF_NPPN	RISCV_IOMMU_PPN_FIELD
+#define RISCV_IOMMU_MSI_MRIF_NID_MSB	BIT_ULL(60)
+
+#endif /* _RISCV_IOMMU_BITS_H_ */
diff --git a/drivers/iommu/riscv/iommu-platform.c b/drivers/iommu/riscv/iommu-platform.c
new file mode 100644
index 000000000000..1b453334fbbe
--- /dev/null
+++ b/drivers/iommu/riscv/iommu-platform.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * RISC-V IOMMU as a platform device
+ *
+ * Copyright © 2023 FORTH-ICS/CARV
+ * Copyright © 2023-2024 Rivos Inc.
+ *
+ * Authors
+ *	Nick Kossifidis <mick@ics.forth.gr>
+ *	Tomasz Jeznach <tjeznach@rivosinc.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include "iommu-bits.h"
+#include "iommu.h"
+
+static int riscv_iommu_platform_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct riscv_iommu_device *iommu = NULL;
+	struct resource *res = NULL;
+	int vec;
+
+	iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
+	if (!iommu)
+		return -ENOMEM;
+
+	iommu->dev = dev;
+	iommu->reg = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(iommu->reg))
+		return dev_err_probe(dev, PTR_ERR(iommu->reg),
+				     "could not map register region\n");
+
+	dev_set_drvdata(dev, iommu);
+
+	/* Check device reported capabilities / features. */
+	iommu->caps = riscv_iommu_readq(iommu, RISCV_IOMMU_REG_CAP);
+	iommu->fctl = riscv_iommu_readl(iommu, RISCV_IOMMU_REG_FCTL);
+
+	/* For now we only support WSI */
+	switch (FIELD_GET(RISCV_IOMMU_CAP_IGS, iommu->caps)) {
+	case RISCV_IOMMU_CAP_IGS_WSI:
+	case RISCV_IOMMU_CAP_IGS_BOTH:
+		break;
+	default:
+		return dev_err_probe(dev, -ENODEV,
+				     "unable to use wire-signaled interrupts\n");
+	}
+
+	iommu->irqs_count = platform_irq_count(pdev);
+	if (iommu->irqs_count <= 0)
+		return dev_err_probe(dev, -ENODEV,
+				     "no IRQ resources provided\n");
+	if (iommu->irqs_count > RISCV_IOMMU_INTR_COUNT)
+		iommu->irqs_count = RISCV_IOMMU_INTR_COUNT;
+
+	for (vec = 0; vec < iommu->irqs_count; vec++)
+		iommu->irqs[vec] = platform_get_irq(pdev, vec);
+
+	/* Enable wire-signaled interrupts, fctl.WSI */
+	if (!(iommu->fctl & RISCV_IOMMU_FCTL_WSI)) {
+		iommu->fctl |= RISCV_IOMMU_FCTL_WSI;
+		riscv_iommu_writel(iommu, RISCV_IOMMU_REG_FCTL, iommu->fctl);
+	}
+
+	return riscv_iommu_init(iommu);
+};
+
+static void riscv_iommu_platform_remove(struct platform_device *pdev)
+{
+	riscv_iommu_remove(dev_get_drvdata(&pdev->dev));
+};
+
+static const struct of_device_id riscv_iommu_of_match[] = {
+	{.compatible = "riscv,iommu",},
+	{},
+};
+
+static struct platform_driver riscv_iommu_platform_driver = {
+	.probe = riscv_iommu_platform_probe,
+	.remove_new = riscv_iommu_platform_remove,
+	.driver = {
+		.name = "riscv,iommu",
+		.of_match_table = riscv_iommu_of_match,
+		.suppress_bind_attrs = true,
+	},
+};
+
+builtin_platform_driver(riscv_iommu_platform_driver);
diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
new file mode 100644
index 000000000000..3c5a6b49669d
--- /dev/null
+++ b/drivers/iommu/riscv/iommu.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * IOMMU API for RISC-V IOMMU implementations.
+ *
+ * Copyright © 2022-2024 Rivos Inc.
+ * Copyright © 2023 FORTH-ICS/CARV
+ *
+ * Authors
+ *	Tomasz Jeznach <tjeznach@rivosinc.com>
+ *	Nick Kossifidis <mick@ics.forth.gr>
+ */
+
+#define pr_fmt(fmt) "riscv-iommu: " fmt
+
+#include <linux/compiler.h>
+#include <linux/crash_dump.h>
+#include <linux/init.h>
+#include <linux/iommu.h>
+#include <linux/kernel.h>
+
+#include "iommu-bits.h"
+#include "iommu.h"
+
+/* Timeouts in [us] */
+#define RISCV_IOMMU_DDTP_TIMEOUT	50000
+
+/*
+ * This is best effort IOMMU translation shutdown flow.
+ * Disable IOMMU without waiting for hardware response.
+ */
+static void riscv_iommu_disable(struct riscv_iommu_device *iommu)
+{
+	riscv_iommu_writeq(iommu, RISCV_IOMMU_REG_DDTP, 0);
+	riscv_iommu_writel(iommu, RISCV_IOMMU_REG_CQCSR, 0);
+	riscv_iommu_writel(iommu, RISCV_IOMMU_REG_FQCSR, 0);
+	riscv_iommu_writel(iommu, RISCV_IOMMU_REG_PQCSR, 0);
+}
+
+static int riscv_iommu_init_check(struct riscv_iommu_device *iommu)
+{
+	u64 ddtp;
+
+	/*
+	 * Make sure the IOMMU is switched off or in pass-through mode during
+	 * regular boot flow and disable translation when we boot into a kexec
+	 * kernel and the previous kernel left them enabled.
+	 */
+	ddtp = riscv_iommu_readq(iommu, RISCV_IOMMU_REG_DDTP);
+	if (ddtp & RISCV_IOMMU_DDTP_BUSY)
+		return -EBUSY;
+
+	if (FIELD_GET(RISCV_IOMMU_DDTP_MODE, ddtp) > RISCV_IOMMU_DDTP_MODE_BARE) {
+		if (!is_kdump_kernel())
+			return -EBUSY;
+		riscv_iommu_disable(iommu);
+	}
+
+	/* Configure accesses to in-memory data structures for CPU-native byte order. */
+	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) != !!(iommu->fctl & RISCV_IOMMU_FCTL_BE)) {
+		if (!(iommu->caps & RISCV_IOMMU_CAP_END))
+			return -EINVAL;
+		riscv_iommu_writel(iommu, RISCV_IOMMU_REG_FCTL,
+				   iommu->fctl ^ RISCV_IOMMU_FCTL_BE);
+		iommu->fctl = riscv_iommu_readl(iommu, RISCV_IOMMU_REG_FCTL);
+		if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) != !!(iommu->fctl & RISCV_IOMMU_FCTL_BE))
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+void riscv_iommu_remove(struct riscv_iommu_device *iommu)
+{
+	iommu_device_sysfs_remove(&iommu->iommu);
+}
+
+int riscv_iommu_init(struct riscv_iommu_device *iommu)
+{
+	int rc;
+
+	rc = riscv_iommu_init_check(iommu);
+	if (rc)
+		return dev_err_probe(iommu->dev, rc, "unexpected device state\n");
+
+	/*
+	 * Placeholder for a complete IOMMU device initialization.  For now,
+	 * only bare minimum: enable global identity mapping mode and register sysfs.
+	 */
+	riscv_iommu_writeq(iommu, RISCV_IOMMU_REG_DDTP,
+			   FIELD_PREP(RISCV_IOMMU_DDTP_MODE, RISCV_IOMMU_DDTP_MODE_BARE));
+
+	rc = iommu_device_sysfs_add(&iommu->iommu, NULL, NULL, "riscv-iommu@%s",
+				    dev_name(iommu->dev));
+	if (rc)
+		return dev_err_probe(iommu->dev, rc,
+				     "cannot register sysfs interface\n");
+
+	return 0;
+}
diff --git a/drivers/iommu/riscv/iommu.h b/drivers/iommu/riscv/iommu.h
new file mode 100644
index 000000000000..700e33dc2446
--- /dev/null
+++ b/drivers/iommu/riscv/iommu.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright © 2022-2024 Rivos Inc.
+ * Copyright © 2023 FORTH-ICS/CARV
+ *
+ * Authors
+ *	Tomasz Jeznach <tjeznach@rivosinc.com>
+ *	Nick Kossifidis <mick@ics.forth.gr>
+ */
+
+#ifndef _RISCV_IOMMU_H_
+#define _RISCV_IOMMU_H_
+
+#include <linux/iommu.h>
+#include <linux/types.h>
+#include <linux/iopoll.h>
+
+#include "iommu-bits.h"
+
+struct riscv_iommu_device {
+	/* iommu core interface */
+	struct iommu_device iommu;
+
+	/* iommu hardware */
+	struct device *dev;
+
+	/* hardware control register space */
+	void __iomem *reg;
+
+	/* supported and enabled hardware capabilities */
+	u64 caps;
+	u32 fctl;
+
+	/* available interrupt numbers, MSI or WSI */
+	unsigned int irqs[RISCV_IOMMU_INTR_COUNT];
+	unsigned int irqs_count;
+};
+
+int riscv_iommu_init(struct riscv_iommu_device *iommu);
+void riscv_iommu_remove(struct riscv_iommu_device *iommu);
+
+#define riscv_iommu_readl(iommu, addr) \
+	readl_relaxed((iommu)->reg + (addr))
+
+#define riscv_iommu_readq(iommu, addr) \
+	readq_relaxed((iommu)->reg + (addr))
+
+#define riscv_iommu_writel(iommu, addr, val) \
+	writel_relaxed((val), (iommu)->reg + (addr))
+
+#define riscv_iommu_writeq(iommu, addr, val) \
+	writeq_relaxed((val), (iommu)->reg + (addr))
+
+#define riscv_iommu_readq_timeout(iommu, addr, val, cond, delay_us, timeout_us) \
+	readx_poll_timeout(readq_relaxed, (iommu)->reg + (addr), val, cond, \
+			   delay_us, timeout_us)
+
+#define riscv_iommu_readl_timeout(iommu, addr, val, cond, delay_us, timeout_us) \
+	readx_poll_timeout(readl_relaxed, (iommu)->reg + (addr), val, cond, \
+			   delay_us, timeout_us)
+
+#endif
-- 
2.34.1