Re: [PATCH v4 2/7] iommu/riscv: Add RISC-V IOMMU platform device driver

[Zong Li <zong.li@sifive.com>]

On Sat, May 4, 2024 at 12:13 AM Tomasz Jeznach <tjeznach@rivosinc.com> wrote:
>
> 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>
> 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 7fcf7c27ef6b..42df3b3871f4 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -18964,6 +18964,7 @@ 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 0af39bbbe3a3..ae762db0365e 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..ba093c29de9f
> --- /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_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)
> +

Could we use ICVEC instead of IVEC for aligning the term in spec? If
it is ok, you might also need to modify it in riscv_iommu_device
structure.


> +/* 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
>
>
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