[PATCH 01/11] RISC-V: drivers/iommu: Add RISC-V IOMMU - Ziommu support.

Tomasz Jeznach tjeznach at rivosinc.com
Wed Jul 19 12:33:45 PDT 2023


The patch introduces skeleton IOMMU device driver implementation as defined
by RISC-V IOMMU Architecture Specification, Version 1.0 [1], with minimal support
for pass-through mapping, basic initialization and bindings for platform and PCIe
hardware implementations.

Series of patches following specification evolution has been reorganized to provide
functional separation of implemented blocks, compliant with ratified specification.

This and following patch series includes code contributed by: Nick Kossifidis
<mick at ics.forth.gr> (iommu-platform device, number of specification clarification
and bugfixes and readability improvements), Sebastien Boeuf <seb at rivosinc.com> (page
table creation, ATS/PGR flow).

Complete history can be found at the maintainer's repository branch [2].

Device driver enables RISC-V 32/64 support for memory translation for DMA capable
PCI and platform devices, multilevel device directory table, process directory,
shared virtual address support, wired and message signaled interrupt for translation
I/O fault, page request interface and command processing.

Matching RISCV-V IOMMU device emulation implementation is available for QEMU project,
along with educational device extensions for PASID ATS/PRI support [3].

References:
 - [1] https://github.com/riscv-non-isa/riscv-iommu
 - [2] https://github.com/tjeznach/linux/tree/tjeznach/riscv-iommu
 - [3] https://github.com/tjeznach/qemu/tree/tjeznach/riscv-iommu

Co-developed-by: Nick Kossifidis <mick at ics.forth.gr>
Signed-off-by: Nick Kossifidis <mick at ics.forth.gr>
Co-developed-by: Sebastien Boeuf <seb at rivosinc.com>
Signed-off-by: Sebastien Boeuf <seb at rivosinc.com>
Signed-off-by: Tomasz Jeznach <tjeznach at rivosinc.com>
---
 drivers/iommu/Kconfig                |   1 +
 drivers/iommu/Makefile               |   2 +-
 drivers/iommu/riscv/Kconfig          |  22 +
 drivers/iommu/riscv/Makefile         |   1 +
 drivers/iommu/riscv/iommu-bits.h     | 704 +++++++++++++++++++++++++++
 drivers/iommu/riscv/iommu-pci.c      | 134 +++++
 drivers/iommu/riscv/iommu-platform.c |  94 ++++
 drivers/iommu/riscv/iommu.c          | 660 +++++++++++++++++++++++++
 drivers/iommu/riscv/iommu.h          | 115 +++++
 9 files changed, 1732 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-pci.c
 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/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 2b12b583ef4b..36fcc6fd5b4e 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -187,6 +187,7 @@ 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 769e43d780ce..8f57110a9fb1 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-$(CONFIG_IOMMU_API) += iommu-sysfs.o
diff --git a/drivers/iommu/riscv/Kconfig b/drivers/iommu/riscv/Kconfig
new file mode 100644
index 000000000000..01d4043849d4
--- /dev/null
+++ b/drivers/iommu/riscv/Kconfig
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# RISC-V IOMMU support
+
+config RISCV_IOMMU
+	bool "RISC-V IOMMU driver"
+	depends on RISCV
+	select IOMMU_API
+	select IOMMU_DMA
+	select IOMMU_SVA
+	select IOMMU_IOVA
+	select IOMMU_IO_PGTABLE
+	select IOASID
+	select PCI_MSI
+	select PCI_ATS
+	select PCI_PRI
+	select PCI_PASID
+	select MMU_NOTIFIER
+	help
+	  Support for devices following RISC-V IOMMU specification.
+
+	  If unsure, say N here.
+
diff --git a/drivers/iommu/riscv/Makefile b/drivers/iommu/riscv/Makefile
new file mode 100644
index 000000000000..38730c11e4a8
--- /dev/null
+++ b/drivers/iommu/riscv/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_RISCV_IOMMU) += iommu.o iommu-pci.o iommu-platform.o
\ No newline at end of file
diff --git a/drivers/iommu/riscv/iommu-bits.h b/drivers/iommu/riscv/iommu-bits.h
new file mode 100644
index 000000000000..b2946793a73d
--- /dev/null
+++ b/drivers/iommu/riscv/iommu-bits.h
@@ -0,0 +1,704 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright © 2022-2023 Rivos Inc.
+ * Copyright © 2023 FORTH-ICS/CARV
+ * Copyright © 2023 RISC-V IOMMU Task Group
+ *
+ * RISC-V Ziommu - 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_MSI_FLAT	BIT_ULL(22)
+#define RISCV_IOMMU_CAP_MSI_MRIF	BIT_ULL(23)
+#define RISCV_IOMMU_CAP_AMO		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
+ */
+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_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_IVEC		0x02F8
+#define RISCV_IOMMU_IVEC_CIV		GENMASK_ULL(3, 0)
+#define RISCV_IOMMU_IVEC_FIV		GENMASK_ULL(7, 4)
+#define RISCV_IOMMU_IVEC_PMIV		GENMASK_ULL(11, 8)
+#define RISCV_IOMMU_IVEC_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
+ * @msiptpt: MSI page table pointer
+ * @msi_addr_mask: MSI address mask
+ * @msi_addr_pattern: MSI address pattern
+ *
+ * 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_cmd - 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 is the address, 4K-alligned and shifted to the right by
+ * two bits. */
+
+/* 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 alligned 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 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-pci.c b/drivers/iommu/riscv/iommu-pci.c
new file mode 100644
index 000000000000..c91f963d7a29
--- /dev/null
+++ b/drivers/iommu/riscv/iommu-pci.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Copyright © 2022-2023 Rivos Inc.
+ * Copyright © 2023 FORTH-ICS/CARV
+ *
+ * RISCV IOMMU as a PCIe device
+ *
+ * Authors
+ *	Tomasz Jeznach <tjeznach at rivosinc.com>
+ *	Nick Kossifidis <mick at ics.forth.gr>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/iommu.h>
+#include <linux/bitfield.h>
+
+#include "iommu.h"
+
+/* Rivos Inc. assigned PCI Vendor and Device IDs */
+#ifndef PCI_VENDOR_ID_RIVOS
+#define PCI_VENDOR_ID_RIVOS             0x1efd
+#endif
+
+#ifndef PCI_DEVICE_ID_RIVOS_IOMMU
+#define PCI_DEVICE_ID_RIVOS_IOMMU       0xedf1
+#endif
+
+static int riscv_iommu_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	struct device *dev = &pdev->dev;
+	struct riscv_iommu_device *iommu;
+	int ret;
+
+	ret = pci_enable_device_mem(pdev);
+	if (ret < 0)
+		return ret;
+
+	ret = pci_request_mem_regions(pdev, KBUILD_MODNAME);
+	if (ret < 0)
+		goto fail;
+
+	ret = -ENOMEM;
+
+	iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
+	if (!iommu)
+		goto fail;
+
+	if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM))
+		goto fail;
+
+	if (pci_resource_len(pdev, 0) < RISCV_IOMMU_REG_SIZE)
+		goto fail;
+
+	iommu->reg_phys = pci_resource_start(pdev, 0);
+	if (!iommu->reg_phys)
+		goto fail;
+
+	iommu->reg = devm_ioremap(dev, iommu->reg_phys, RISCV_IOMMU_REG_SIZE);
+	if (!iommu->reg)
+		goto fail;
+
+	iommu->dev = dev;
+	dev_set_drvdata(dev, iommu);
+
+	dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+	pci_set_master(pdev);
+
+	ret = riscv_iommu_init(iommu);
+	if (!ret)
+		return ret;
+
+ fail:
+	pci_clear_master(pdev);
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+	/* Note: devres_release_all() will release iommu and iommu->reg */
+	return ret;
+}
+
+static void riscv_iommu_pci_remove(struct pci_dev *pdev)
+{
+	riscv_iommu_remove(dev_get_drvdata(&pdev->dev));
+	pci_clear_master(pdev);
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+}
+
+static int riscv_iommu_suspend(struct device *dev)
+{
+	dev_warn(dev, "RISC-V IOMMU PM not implemented");
+	return -ENODEV;
+}
+
+static int riscv_iommu_resume(struct device *dev)
+{
+	dev_warn(dev, "RISC-V IOMMU PM not implemented");
+	return -ENODEV;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(riscv_iommu_pm_ops, riscv_iommu_suspend,
+				riscv_iommu_resume);
+
+static const struct pci_device_id riscv_iommu_pci_tbl[] = {
+	{PCI_VENDOR_ID_RIVOS, PCI_DEVICE_ID_RIVOS_IOMMU,
+	 PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
+	{0,}
+};
+
+MODULE_DEVICE_TABLE(pci, riscv_iommu_pci_tbl);
+
+static const struct of_device_id riscv_iommu_of_match[] = {
+	{.compatible = "riscv,pci-iommu",},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, riscv_iommu_of_match);
+
+static struct pci_driver riscv_iommu_pci_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = riscv_iommu_pci_tbl,
+	.probe = riscv_iommu_pci_probe,
+	.remove = riscv_iommu_pci_remove,
+	.driver = {
+		   .pm = pm_sleep_ptr(&riscv_iommu_pm_ops),
+		   .of_match_table = riscv_iommu_of_match,
+		   },
+};
+
+module_driver(riscv_iommu_pci_driver, pci_register_driver, pci_unregister_driver);
diff --git a/drivers/iommu/riscv/iommu-platform.c b/drivers/iommu/riscv/iommu-platform.c
new file mode 100644
index 000000000000..e4e8ca6711e7
--- /dev/null
+++ b/drivers/iommu/riscv/iommu-platform.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * RISC-V IOMMU as a platform device
+ *
+ * Copyright © 2023 FORTH-ICS/CARV
+ *
+ * Author: Nick Kossifidis <mick at ics.forth.gr>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/of_platform.h>
+#include <linux/bitfield.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 ret = 0;
+
+	iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
+	if (!iommu)
+		return -ENOMEM;
+
+	iommu->dev = dev;
+	dev_set_drvdata(dev, iommu);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "could not find resource for register region\n");
+		return -EINVAL;
+	}
+
+	iommu->reg = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(iommu->reg)) {
+		ret = dev_err_probe(dev, PTR_ERR(iommu->reg),
+				    "could not map register region\n");
+		goto fail;
+	};
+
+	iommu->reg_phys = res->start;
+
+	ret = -ENODEV;
+
+	/* Sanity check: Did we get the whole register space ? */
+	if ((res->end - res->start + 1) < RISCV_IOMMU_REG_SIZE) {
+		dev_err(dev, "device region smaller than register file (0x%llx)\n",
+			res->end - res->start);
+		goto fail;
+	}
+
+	dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+
+	return riscv_iommu_init(iommu);
+
+ fail:
+	/* Note: devres_release_all() will release iommu and iommu->reg */
+	return ret;
+};
+
+static void riscv_iommu_platform_remove(struct platform_device *pdev)
+{
+	riscv_iommu_remove(dev_get_drvdata(&pdev->dev));
+};
+
+static void riscv_iommu_platform_shutdown(struct platform_device *pdev)
+{
+	return;
+};
+
+static const struct of_device_id riscv_iommu_of_match[] = {
+	{.compatible = "riscv,iommu",},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, riscv_iommu_of_match);
+
+static struct platform_driver riscv_iommu_platform_driver = {
+	.driver = {
+		   .name = "riscv,iommu",
+		   .of_match_table = riscv_iommu_of_match,
+		   .suppress_bind_attrs = true,
+		   },
+	.probe = riscv_iommu_platform_probe,
+	.remove_new = riscv_iommu_platform_remove,
+	.shutdown = riscv_iommu_platform_shutdown,
+};
+
+module_driver(riscv_iommu_platform_driver, platform_driver_register,
+	      platform_driver_unregister);
diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
new file mode 100644
index 000000000000..8c236242e2cc
--- /dev/null
+++ b/drivers/iommu/riscv/iommu.c
@@ -0,0 +1,660 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * IOMMU API for RISC-V architected Ziommu implementations.
+ *
+ * Copyright © 2022-2023 Rivos Inc.
+ * Copyright © 2023 FORTH-ICS/CARV
+ *
+ * Authors
+ *	Tomasz Jeznach <tjeznach at rivosinc.com>
+ *	Nick Kossifidis <mick at ics.forth.gr>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/bitfield.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/pci.h>
+#include <linux/pci-ats.h>
+#include <linux/init.h>
+#include <linux/completion.h>
+#include <linux/uaccess.h>
+#include <linux/iommu.h>
+#include <linux/irqdomain.h>
+#include <linux/platform_device.h>
+#include <linux/dma-map-ops.h>
+#include <asm/page.h>
+
+#include "../dma-iommu.h"
+#include "../iommu-sva.h"
+#include "iommu.h"
+
+#include <asm/csr.h>
+#include <asm/delay.h>
+
+MODULE_DESCRIPTION("IOMMU driver for RISC-V architected Ziommu implementations");
+MODULE_AUTHOR("Tomasz Jeznach <tjeznach at rivosinc.com>");
+MODULE_AUTHOR("Nick Kossifidis <mick at ics.forth.gr>");
+MODULE_ALIAS("riscv-iommu");
+MODULE_LICENSE("GPL v2");
+
+/* Global IOMMU params. */
+static int ddt_mode = RISCV_IOMMU_DDTP_MODE_BARE;
+module_param(ddt_mode, int, 0644);
+MODULE_PARM_DESC(ddt_mode, "Device Directory Table mode.");
+
+/* IOMMU PSCID allocation namespace. */
+#define RISCV_IOMMU_MAX_PSCID	(1U << 20)
+static DEFINE_IDA(riscv_iommu_pscids);
+
+/* 1 second */
+#define RISCV_IOMMU_TIMEOUT	riscv_timebase
+
+/* RISC-V IOMMU PPN <> PHYS address conversions, PHYS <=> PPN[53:10] */
+#define phys_to_ppn(va)  (((va) >> 2) & (((1ULL << 44) - 1) << 10))
+#define ppn_to_phys(pn)	 (((pn) << 2) & (((1ULL << 44) - 1) << 12))
+
+#define iommu_domain_to_riscv(iommu_domain) \
+    container_of(iommu_domain, struct riscv_iommu_domain, domain)
+
+#define iommu_device_to_riscv(iommu_device) \
+    container_of(iommu_device, struct riscv_iommu, iommu)
+
+static const struct iommu_domain_ops riscv_iommu_domain_ops;
+static const struct iommu_ops riscv_iommu_ops;
+
+/*
+ * Register device for IOMMU tracking.
+ */
+static void riscv_iommu_add_device(struct riscv_iommu_device *iommu, struct device *dev)
+{
+	struct riscv_iommu_endpoint *ep, *rb_ep;
+	struct rb_node **new_node, *parent_node = NULL;
+
+	mutex_lock(&iommu->eps_mutex);
+
+	ep = dev_iommu_priv_get(dev);
+
+	new_node = &(iommu->eps.rb_node);
+	while (*new_node) {
+		rb_ep = rb_entry(*new_node, struct riscv_iommu_endpoint, node);
+		parent_node = *new_node;
+		if (rb_ep->devid > ep->devid) {
+			new_node = &((*new_node)->rb_left);
+		} else if (rb_ep->devid < ep->devid) {
+			new_node = &((*new_node)->rb_right);
+		} else {
+			dev_warn(dev, "device %u already in the tree\n", ep->devid);
+			break;
+		}
+	}
+
+	rb_link_node(&ep->node, parent_node, new_node);
+	rb_insert_color(&ep->node, &iommu->eps);
+
+	mutex_unlock(&iommu->eps_mutex);
+}
+
+/*
+ * Endpoint management
+ */
+
+static int riscv_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)
+{
+	return iommu_fwspec_add_ids(dev, args->args, 1);
+}
+
+static bool riscv_iommu_capable(struct device *dev, enum iommu_cap cap)
+{
+	switch (cap) {
+	case IOMMU_CAP_CACHE_COHERENCY:
+	case IOMMU_CAP_PRE_BOOT_PROTECTION:
+		return true;
+
+	default:
+		break;
+	}
+
+	return false;
+}
+
+static struct iommu_device *riscv_iommu_probe_device(struct device *dev)
+{
+	struct riscv_iommu_device *iommu;
+	struct riscv_iommu_endpoint *ep;
+	struct iommu_fwspec *fwspec;
+
+	fwspec = dev_iommu_fwspec_get(dev);
+	if (!fwspec || fwspec->ops != &riscv_iommu_ops ||
+	    !fwspec->iommu_fwnode || !fwspec->iommu_fwnode->dev)
+		return ERR_PTR(-ENODEV);
+
+	iommu = dev_get_drvdata(fwspec->iommu_fwnode->dev);
+	if (!iommu)
+		return ERR_PTR(-ENODEV);
+
+	if (dev_iommu_priv_get(dev))
+		return &iommu->iommu;
+
+	ep = kzalloc(sizeof(*ep), GFP_KERNEL);
+	if (!ep)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_init(&ep->lock);
+	INIT_LIST_HEAD(&ep->domain);
+
+	if (dev_is_pci(dev)) {
+		ep->devid = pci_dev_id(to_pci_dev(dev));
+		ep->domid = pci_domain_nr(to_pci_dev(dev)->bus);
+	} else {
+		/* TODO: Make this generic, for now hardcode domain id to 0 */
+		ep->devid = fwspec->ids[0];
+		ep->domid = 0;
+	}
+
+	ep->iommu = iommu;
+	ep->dev = dev;
+
+	dev_info(iommu->dev, "adding device to iommu with devid %i in domain %i\n",
+		ep->devid, ep->domid);
+
+	dev_iommu_priv_set(dev, ep);
+	riscv_iommu_add_device(iommu, dev);
+
+	return &iommu->iommu;
+}
+
+static void riscv_iommu_probe_finalize(struct device *dev)
+{
+	set_dma_ops(dev, NULL);
+	iommu_setup_dma_ops(dev, 0, U64_MAX);
+}
+
+static void riscv_iommu_release_device(struct device *dev)
+{
+	struct riscv_iommu_endpoint *ep = dev_iommu_priv_get(dev);
+	struct riscv_iommu_device *iommu = ep->iommu;
+
+	dev_info(dev, "device with devid %i released\n", ep->devid);
+
+	mutex_lock(&ep->lock);
+	list_del(&ep->domain);
+	mutex_unlock(&ep->lock);
+
+	/* Remove endpoint from IOMMU tracking structures */
+	mutex_lock(&iommu->eps_mutex);
+	rb_erase(&ep->node, &iommu->eps);
+	mutex_unlock(&iommu->eps_mutex);
+
+	set_dma_ops(dev, NULL);
+	dev_iommu_priv_set(dev, NULL);
+
+	kfree(ep);
+}
+
+static struct iommu_group *riscv_iommu_device_group(struct device *dev)
+{
+	if (dev_is_pci(dev))
+		return pci_device_group(dev);
+	return generic_device_group(dev);
+}
+
+static void riscv_iommu_get_resv_regions(struct device *dev, struct list_head *head)
+{
+	iommu_dma_get_resv_regions(dev, head);
+}
+
+/*
+ * Domain management
+ */
+
+static struct iommu_domain *riscv_iommu_domain_alloc(unsigned type)
+{
+	struct riscv_iommu_domain *domain;
+
+	if (type != IOMMU_DOMAIN_IDENTITY &&
+	    type != IOMMU_DOMAIN_BLOCKED)
+		return NULL;
+
+	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+	if (!domain)
+		return NULL;
+
+	mutex_init(&domain->lock);
+	INIT_LIST_HEAD(&domain->endpoints);
+
+	domain->domain.ops = &riscv_iommu_domain_ops;
+	domain->mode = RISCV_IOMMU_DC_FSC_MODE_BARE;
+	domain->pscid = ida_alloc_range(&riscv_iommu_pscids, 1,
+					RISCV_IOMMU_MAX_PSCID, GFP_KERNEL);
+
+	printk("domain type %x alloc %u\n", type, domain->pscid);
+
+	return &domain->domain;
+}
+
+static void riscv_iommu_domain_free(struct iommu_domain *iommu_domain)
+{
+	struct riscv_iommu_domain *domain = iommu_domain_to_riscv(iommu_domain);
+
+	if (!list_empty(&domain->endpoints)) {
+		pr_warn("IOMMU domain is not empty!\n");
+	}
+
+	if (domain->pgd_root)
+		free_pages((unsigned long)domain->pgd_root, 0);
+
+	if ((int)domain->pscid > 0)
+		ida_free(&riscv_iommu_pscids, domain->pscid);
+
+	printk("domain free %u\n", domain->pscid);
+
+	kfree(domain);
+}
+
+static int riscv_iommu_domain_finalize(struct riscv_iommu_domain *domain,
+				       struct riscv_iommu_device *iommu)
+{
+	struct iommu_domain_geometry *geometry;
+
+	/* Domain assigned to another iommu */
+	if (domain->iommu && domain->iommu != iommu)
+		return -EINVAL;
+	/* Domain already initialized */
+	else if (domain->iommu)
+		return 0;
+
+	/*
+	 * TODO: Before using VA_BITS and satp_mode here, verify they
+	 * are supported by the iommu, through the capabilities register.
+	 */
+
+	geometry = &domain->domain.geometry;
+
+	/*
+	 * Note: RISC-V Privilege spec mandates that virtual addresses
+	 * need to be sign-extended, so if (VA_BITS - 1) is set, all
+	 * bits >= VA_BITS need to also be set or else we'll get a
+	 * page fault. However the code that creates the mappings
+	 * above us (e.g. iommu_dma_alloc_iova()) won't do that for us
+	 * for now, so we'll end up with invalid virtual addresses
+	 * to map. As a workaround until we get this sorted out
+	 * limit the available virtual addresses to VA_BITS - 1.
+	 */
+	geometry->aperture_start = 0;
+	geometry->aperture_end = DMA_BIT_MASK(VA_BITS - 1);
+	geometry->force_aperture = true;
+
+	domain->iommu = iommu;
+
+	if (domain->domain.type == IOMMU_DOMAIN_IDENTITY)
+		return 0;
+
+	/* TODO: Fix this for RV32 */
+	domain->mode = satp_mode >> 60;
+	domain->pgd_root = (pgd_t *) __get_free_pages(GFP_KERNEL | __GFP_ZERO, 0);
+
+	if (!domain->pgd_root)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int riscv_iommu_attach_dev(struct iommu_domain *iommu_domain, struct device *dev)
+{
+	struct riscv_iommu_domain *domain = iommu_domain_to_riscv(iommu_domain);
+	struct riscv_iommu_endpoint *ep = dev_iommu_priv_get(dev);
+	int ret;
+
+	/* PSCID not valid */
+	if ((int)domain->pscid < 0)
+		return -ENOMEM;
+
+	mutex_lock(&domain->lock);
+	mutex_lock(&ep->lock);
+
+	if (!list_empty(&ep->domain)) {
+		dev_warn(dev, "endpoint already attached to a domain. dropping\n");
+		list_del_init(&ep->domain);
+	}
+
+	/* allocate root pages, initialize io-pgtable ops, etc. */
+	ret = riscv_iommu_domain_finalize(domain, ep->iommu);
+	if (ret < 0) {
+		dev_err(dev, "can not finalize domain: %d\n", ret);
+		mutex_unlock(&ep->lock);
+		mutex_unlock(&domain->lock);
+		return ret;
+	}
+
+	if (ep->iommu->ddt_mode != RISCV_IOMMU_DDTP_MODE_BARE ||
+	    domain->domain.type != IOMMU_DOMAIN_IDENTITY) {
+		dev_warn(dev, "domain type %d not supported\n",
+		    domain->domain.type);
+		return -ENODEV;
+	}
+
+	list_add_tail(&ep->domain, &domain->endpoints);
+	mutex_unlock(&ep->lock);
+	mutex_unlock(&domain->lock);
+
+	dev_info(dev, "domain type %d attached w/ PSCID %u\n",
+	    domain->domain.type, domain->pscid);
+
+	return 0;
+}
+
+static void riscv_iommu_flush_iotlb_range(struct iommu_domain *iommu_domain,
+					  unsigned long *start, unsigned long *end,
+					  size_t *pgsize)
+{
+	/* Command interface not implemented */
+}
+
+static void riscv_iommu_flush_iotlb_all(struct iommu_domain *iommu_domain)
+{
+	riscv_iommu_flush_iotlb_range(iommu_domain, NULL, NULL, NULL);
+}
+
+static void riscv_iommu_iotlb_sync(struct iommu_domain *iommu_domain,
+				   struct iommu_iotlb_gather *gather)
+{
+	riscv_iommu_flush_iotlb_range(iommu_domain, &gather->start, &gather->end,
+				      &gather->pgsize);
+}
+
+static void riscv_iommu_iotlb_sync_map(struct iommu_domain *iommu_domain,
+				       unsigned long iova, size_t size)
+{
+	unsigned long end = iova + size - 1;
+	/*
+	 * Given we don't know the page size used by this range, we assume the
+	 * smallest page size to ensure all possible entries are flushed from
+	 * the IOATC.
+	 */
+	size_t pgsize = PAGE_SIZE;
+	riscv_iommu_flush_iotlb_range(iommu_domain, &iova, &end, &pgsize);
+}
+
+static int riscv_iommu_map_pages(struct iommu_domain *iommu_domain,
+				 unsigned long iova, phys_addr_t phys,
+				 size_t pgsize, size_t pgcount, int prot,
+				 gfp_t gfp, size_t *mapped)
+{
+	struct riscv_iommu_domain *domain = iommu_domain_to_riscv(iommu_domain);
+
+	if (domain->domain.type == IOMMU_DOMAIN_IDENTITY) {
+		*mapped = pgsize * pgcount;
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
+static size_t riscv_iommu_unmap_pages(struct iommu_domain *iommu_domain,
+				      unsigned long iova, size_t pgsize,
+				      size_t pgcount, struct iommu_iotlb_gather *gather)
+{
+	struct riscv_iommu_domain *domain = iommu_domain_to_riscv(iommu_domain);
+
+	if (domain->domain.type == IOMMU_DOMAIN_IDENTITY)
+		return pgsize * pgcount;
+
+	return 0;
+}
+
+static phys_addr_t riscv_iommu_iova_to_phys(struct iommu_domain *iommu_domain,
+					    dma_addr_t iova)
+{
+	struct riscv_iommu_domain *domain = iommu_domain_to_riscv(iommu_domain);
+
+	if (domain->domain.type == IOMMU_DOMAIN_IDENTITY)
+		return (phys_addr_t) iova;
+
+	return 0;
+}
+
+/*
+ * Translation mode setup
+ */
+
+static u64 riscv_iommu_get_ddtp(struct riscv_iommu_device *iommu)
+{
+	u64 ddtp;
+	cycles_t end_cycles = RISCV_IOMMU_TIMEOUT + get_cycles();
+
+	/* Wait for DDTP.BUSY to be cleared and return latest value */
+	do {
+		ddtp = riscv_iommu_readq(iommu, RISCV_IOMMU_REG_DDTP);
+		if (!(ddtp & RISCV_IOMMU_DDTP_BUSY))
+			break;
+		cpu_relax();
+	} while (get_cycles() < end_cycles);
+
+	return ddtp;
+}
+
+static void riscv_iommu_ddt_cleanup(struct riscv_iommu_device *iommu)
+{
+	/* TODO: teardown whole device directory tree. */
+	if (iommu->ddtp) {
+		if (iommu->ddtp_in_iomem) {
+			iounmap((void *)iommu->ddtp);
+		} else
+			free_page(iommu->ddtp);
+		iommu->ddtp = 0;
+	}
+}
+
+static int riscv_iommu_enable(struct riscv_iommu_device *iommu, unsigned requested_mode)
+{
+	struct device *dev = iommu->dev;
+	u64 ddtp = 0;
+	u64 ddtp_paddr = 0;
+	unsigned mode = requested_mode;
+	unsigned mode_readback = 0;
+
+	ddtp = riscv_iommu_get_ddtp(iommu);
+	if (ddtp & RISCV_IOMMU_DDTP_BUSY)
+		return -EBUSY;
+
+	/* Disallow state transtion from xLVL to xLVL. */
+	switch (FIELD_GET(RISCV_IOMMU_DDTP_MODE, ddtp)) {
+	case RISCV_IOMMU_DDTP_MODE_BARE:
+	case RISCV_IOMMU_DDTP_MODE_OFF:
+		break;
+	default:
+		if ((mode != RISCV_IOMMU_DDTP_MODE_BARE)
+		    && (mode != RISCV_IOMMU_DDTP_MODE_OFF))
+			return -EINVAL;
+		break;
+	}
+
+ retry:
+	switch (mode) {
+	case RISCV_IOMMU_DDTP_MODE_BARE:
+	case RISCV_IOMMU_DDTP_MODE_OFF:
+		riscv_iommu_ddt_cleanup(iommu);
+		ddtp = FIELD_PREP(RISCV_IOMMU_DDTP_MODE, mode);
+		break;
+	case RISCV_IOMMU_DDTP_MODE_1LVL:
+	case RISCV_IOMMU_DDTP_MODE_2LVL:
+	case RISCV_IOMMU_DDTP_MODE_3LVL:
+		if (!iommu->ddtp) {
+			/*
+			 * We haven't initialized ddtp yet, since it's WARL make
+			 * sure that we don't have a hardwired PPN field there
+			 * that points to i/o memory instead.
+			 */
+			riscv_iommu_writeq(iommu, RISCV_IOMMU_REG_DDTP, 0);
+			ddtp = riscv_iommu_get_ddtp(iommu);
+			ddtp_paddr = ppn_to_phys(ddtp);
+			if (ddtp_paddr) {
+				dev_warn(dev, "ddtp at 0x%llx\n", ddtp_paddr);
+				iommu->ddtp =
+				    (unsigned long)ioremap(ddtp_paddr, PAGE_SIZE);
+				iommu->ddtp_in_iomem = true;
+			} else {
+				iommu->ddtp = get_zeroed_page(GFP_KERNEL);
+			}
+		}
+		if (!iommu->ddtp)
+			return -ENOMEM;
+
+		ddtp = FIELD_PREP(RISCV_IOMMU_DDTP_MODE, mode) |
+		    phys_to_ppn(__pa(iommu->ddtp));
+
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	riscv_iommu_writeq(iommu, RISCV_IOMMU_REG_DDTP, ddtp);
+	ddtp = riscv_iommu_get_ddtp(iommu);
+	if (ddtp & RISCV_IOMMU_DDTP_BUSY) {
+		dev_warn(dev, "timeout when setting ddtp (ddt mode: %i)\n", mode);
+		return -EBUSY;
+	}
+
+	mode_readback = FIELD_GET(RISCV_IOMMU_DDTP_MODE, ddtp);
+	dev_info(dev, "mode_readback: %i, mode: %i\n", mode_readback, mode);
+	if (mode_readback != mode) {
+		/*
+		 * Mode field is WARL, an I/O MMU may support a subset of
+		 * directory table levels in which case if we tried to set
+		 * an unsupported number of levels we'll readback either
+		 * a valid xLVL or off/bare. If we got off/bare, try again
+		 * with a smaller xLVL.
+		 */
+		if (mode_readback < RISCV_IOMMU_DDTP_MODE_1LVL &&
+		    mode > RISCV_IOMMU_DDTP_MODE_1LVL) {
+			mode--;
+			goto retry;
+		}
+
+		/*
+		 * We tried all supported xLVL modes and still got off/bare instead,
+		 * an I/O MMU must support at least one supported xLVL mode so something
+		 * went very wrong.
+		 */
+		if (mode_readback < RISCV_IOMMU_DDTP_MODE_1LVL &&
+		    mode == RISCV_IOMMU_DDTP_MODE_1LVL)
+			goto fail;
+
+		/*
+		 * We tried setting off or bare and got something else back, something
+		 * went very wrong since off/bare is always legal.
+		 */
+		if (mode < RISCV_IOMMU_DDTP_MODE_1LVL)
+			goto fail;
+
+		/*
+		 * We tried setting an xLVL mode but got another xLVL mode that
+		 * we don't support (e.g. a custom one).
+		 */
+		if (mode_readback > RISCV_IOMMU_DDTP_MODE_MAX)
+			goto fail;
+
+		/* We tried setting an xLVL mode but got another supported xLVL mode */
+		mode = mode_readback;
+	}
+
+	if (mode != requested_mode)
+		dev_warn(dev, "unsupported DDT mode requested (%i), using %i instead\n",
+			 requested_mode, mode);
+
+	iommu->ddt_mode = mode;
+	dev_info(dev, "ddt_mode: %i\n", iommu->ddt_mode);
+	return 0;
+
+ fail:
+	dev_err(dev, "failed to set DDT mode, tried: %i and got %i\n", mode,
+		mode_readback);
+	riscv_iommu_ddt_cleanup(iommu);
+	return -EINVAL;
+}
+
+/*
+ * Common I/O MMU driver probe/teardown
+ */
+
+static const struct iommu_domain_ops riscv_iommu_domain_ops = {
+	.free = riscv_iommu_domain_free,
+	.attach_dev = riscv_iommu_attach_dev,
+	.map_pages = riscv_iommu_map_pages,
+	.unmap_pages = riscv_iommu_unmap_pages,
+	.iova_to_phys = riscv_iommu_iova_to_phys,
+	.iotlb_sync = riscv_iommu_iotlb_sync,
+	.iotlb_sync_map = riscv_iommu_iotlb_sync_map,
+	.flush_iotlb_all = riscv_iommu_flush_iotlb_all,
+};
+
+static const struct iommu_ops riscv_iommu_ops = {
+	.owner = THIS_MODULE,
+	.pgsize_bitmap = SZ_4K | SZ_2M | SZ_512M,
+	.capable = riscv_iommu_capable,
+	.domain_alloc = riscv_iommu_domain_alloc,
+	.probe_device = riscv_iommu_probe_device,
+	.probe_finalize = riscv_iommu_probe_finalize,
+	.release_device = riscv_iommu_release_device,
+	.device_group = riscv_iommu_device_group,
+	.get_resv_regions = riscv_iommu_get_resv_regions,
+	.of_xlate = riscv_iommu_of_xlate,
+	.default_domain_ops = &riscv_iommu_domain_ops,
+};
+
+void riscv_iommu_remove(struct riscv_iommu_device *iommu)
+{
+	iommu_device_unregister(&iommu->iommu);
+	riscv_iommu_enable(iommu, RISCV_IOMMU_DDTP_MODE_OFF);
+}
+
+int riscv_iommu_init(struct riscv_iommu_device *iommu)
+{
+	struct device *dev = iommu->dev;
+	u32 fctl = 0;
+	int ret;
+
+	iommu->eps = RB_ROOT;
+
+	fctl = riscv_iommu_readl(iommu, RISCV_IOMMU_REG_FCTL);
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+	if (!(cap & RISCV_IOMMU_CAP_END)) {
+		dev_err(dev, "IOMMU doesn't support Big Endian\n");
+		return -EIO;
+	} else if (!(fctl & RISCV_IOMMU_FCTL_BE)) {
+		fctl |= FIELD_PREP(RISCV_IOMMU_FCTL_BE, 1);
+		riscv_iommu_writel(iommu, RISCV_IOMMU_REG_FCTL, fctl);
+	}
+#endif
+
+	/* Clear any pending interrupt flag. */
+	riscv_iommu_writel(iommu, RISCV_IOMMU_REG_IPSR,
+			   RISCV_IOMMU_IPSR_CIP |
+			   RISCV_IOMMU_IPSR_FIP |
+			   RISCV_IOMMU_IPSR_PMIP | RISCV_IOMMU_IPSR_PIP);
+	spin_lock_init(&iommu->cq_lock);
+	mutex_init(&iommu->eps_mutex);
+
+	ret = riscv_iommu_enable(iommu, RISCV_IOMMU_DDTP_MODE_BARE);
+
+	if (ret) {
+		dev_err(dev, "cannot enable iommu device (%d)\n", ret);
+		goto fail;
+	}
+
+	ret = iommu_device_register(&iommu->iommu, &riscv_iommu_ops, dev);
+	if (ret) {
+		dev_err(dev, "cannot register iommu interface (%d)\n", ret);
+		iommu_device_sysfs_remove(&iommu->iommu);
+		goto fail;
+	}
+
+	return 0;
+ fail:
+	riscv_iommu_enable(iommu, RISCV_IOMMU_DDTP_MODE_OFF);
+	return ret;
+}
diff --git a/drivers/iommu/riscv/iommu.h b/drivers/iommu/riscv/iommu.h
new file mode 100644
index 000000000000..7baefd3630b3
--- /dev/null
+++ b/drivers/iommu/riscv/iommu.h
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright © 2022-2023 Rivos Inc.
+ * Copyright © 2023 FORTH-ICS/CARV
+ *
+ * RISC-V Ziommu - IOMMU Interface Specification.
+ *
+ * Authors
+ *	Tomasz Jeznach <tjeznach at rivosinc.com>
+ *	Nick Kossifidis <mick at ics.forth.gr>
+ */
+
+#ifndef _RISCV_IOMMU_H_
+#define _RISCV_IOMMU_H_
+
+#include <linux/types.h>
+#include <linux/iova.h>
+#include <linux/io.h>
+#include <linux/idr.h>
+#include <linux/list.h>
+#include <linux/iommu.h>
+#include <linux/io-pgtable.h>
+
+#include "iommu-bits.h"
+
+#define IOMMU_PAGE_SIZE_4K	BIT_ULL(12)
+#define IOMMU_PAGE_SIZE_2M	BIT_ULL(21)
+#define IOMMU_PAGE_SIZE_1G	BIT_ULL(30)
+#define IOMMU_PAGE_SIZE_512G	BIT_ULL(39)
+
+struct riscv_iommu_device {
+	struct iommu_device iommu;	/* iommu core interface */
+	struct device *dev;		/* iommu hardware */
+
+	/* hardware control register space */
+	void __iomem *reg;
+	resource_size_t reg_phys;
+
+	/* IRQs for the various queues */
+	int irq_cmdq;
+	int irq_fltq;
+	int irq_pm;
+	int irq_priq;
+
+	/* supported and enabled hardware capabilities */
+	u64 cap;
+
+	/* global lock, to be removed */
+	spinlock_t cq_lock;
+
+	/* device directory table root pointer and mode */
+	unsigned long ddtp;
+	unsigned ddt_mode;
+	bool ddtp_in_iomem;
+
+	/* Connected end-points */
+	struct rb_root eps;
+	struct mutex eps_mutex;
+};
+
+struct riscv_iommu_domain {
+	struct iommu_domain domain;
+
+	struct list_head endpoints;
+	struct mutex lock;
+	struct riscv_iommu_device *iommu;
+
+	unsigned mode;		/* RIO_ATP_MODE_* enum */
+	unsigned pscid;		/* RISC-V IOMMU PSCID */
+
+	pgd_t *pgd_root;	/* page table root pointer */
+};
+
+/* Private dev_iommu_priv object, device-domain relationship. */
+struct riscv_iommu_endpoint {
+	struct device *dev;			/* platform or PCI endpoint device */
+	unsigned devid;      			/* PCI bus:device:function number */
+	unsigned domid;    			/* PCI domain number, segment */
+	struct rb_node node;    		/* device tracking node (lookup by devid) */
+	struct riscv_iommu_device *iommu;	/* parent iommu device */
+
+	struct mutex lock;
+	struct list_head domain;		/* endpoint attached managed domain */
+};
+
+/* Helper functions and macros */
+
+static inline u32 riscv_iommu_readl(struct riscv_iommu_device *iommu,
+				    unsigned offset)
+{
+	return readl_relaxed(iommu->reg + offset);
+}
+
+static inline void riscv_iommu_writel(struct riscv_iommu_device *iommu,
+				      unsigned offset, u32 val)
+{
+	writel_relaxed(val, iommu->reg + offset);
+}
+
+static inline u64 riscv_iommu_readq(struct riscv_iommu_device *iommu,
+				    unsigned offset)
+{
+	return readq_relaxed(iommu->reg + offset);
+}
+
+static inline void riscv_iommu_writeq(struct riscv_iommu_device *iommu,
+				      unsigned offset, u64 val)
+{
+	writeq_relaxed(val, iommu->reg + offset);
+}
+
+int riscv_iommu_init(struct riscv_iommu_device *iommu);
+void riscv_iommu_remove(struct riscv_iommu_device *iommu);
+
+#endif
-- 
2.34.1




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