[PATCH v8 3/7] iommu/riscv: Add RISC-V IOMMU PCIe device driver
Jim Shu
jim.shu at sifive.com
Fri Aug 30 00:04:35 PDT 2024
Hi Tomasz,
QEMU RISC-V IOMMU will switch the PCIe vendor/device ID to Red Hat one
[1] in the latest v6 patch.
Will we also support the PCIe ID of Red Hat one in the Linux driver?
[1] https://patchew.org/QEMU/20240801154334.1009852-1-dbarboza@ventanamicro.com/20240801154334.1009852-5-dbarboza@ventanamicro.com/
Regards,
Jim Shu
On Sat, Jun 15, 2024 at 1:29 PM Tomasz Jeznach <tjeznach at rivosinc.com> wrote:
>
> Introduce device driver for PCIe implementation
> of RISC-V IOMMU architected hardware.
>
> IOMMU hardware and system support for MSI or MSI-X is
> required by this implementation.
>
> Vendor and device identifiers used in this patch
> matches QEMU implementation of the RISC-V IOMMU PCIe
> device, from Rivos VID (0x1efd) range allocated by the PCI-SIG.
>
> MAINTAINERS | added iommu-pci.c already covered by matching pattern.
>
> Link: https://lore.kernel.org/qemu-devel/20240307160319.675044-1-dbarboza@ventanamicro.com/
> Co-developed-by: Nick Kossifidis <mick at ics.forth.gr>
> Signed-off-by: Nick Kossifidis <mick at ics.forth.gr>
> Reviewed-by: Lu Baolu <baolu.lu at linux.intel.com>
> Signed-off-by: Tomasz Jeznach <tjeznach at rivosinc.com>
> ---
> drivers/iommu/riscv/Kconfig | 5 ++
> drivers/iommu/riscv/Makefile | 1 +
> drivers/iommu/riscv/iommu-pci.c | 119 ++++++++++++++++++++++++++++++++
> 3 files changed, 125 insertions(+)
> create mode 100644 drivers/iommu/riscv/iommu-pci.c
>
> diff --git a/drivers/iommu/riscv/Kconfig b/drivers/iommu/riscv/Kconfig
> index 5dcc5c45aa50..c071816f59a6 100644
> --- a/drivers/iommu/riscv/Kconfig
> +++ b/drivers/iommu/riscv/Kconfig
> @@ -13,3 +13,8 @@ config RISCV_IOMMU
>
> Say Y here if your SoC includes an IOMMU device implementing
> the RISC-V IOMMU architecture.
> +
> +config RISCV_IOMMU_PCI
> + def_bool y if RISCV_IOMMU && PCI_MSI
> + help
> + Support for the PCIe implementation of RISC-V IOMMU architecture.
> diff --git a/drivers/iommu/riscv/Makefile b/drivers/iommu/riscv/Makefile
> index e4c189de58d3..f54c9ed17d41 100644
> --- a/drivers/iommu/riscv/Makefile
> +++ b/drivers/iommu/riscv/Makefile
> @@ -1,2 +1,3 @@
> # SPDX-License-Identifier: GPL-2.0-only
> obj-$(CONFIG_RISCV_IOMMU) += iommu.o iommu-platform.o
> +obj-$(CONFIG_RISCV_IOMMU_PCI) += iommu-pci.o
> diff --git a/drivers/iommu/riscv/iommu-pci.c b/drivers/iommu/riscv/iommu-pci.c
> new file mode 100644
> index 000000000000..e675acceb290
> --- /dev/null
> +++ b/drivers/iommu/riscv/iommu-pci.c
> @@ -0,0 +1,119 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +/*
> + * Copyright © 2022-2024 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/compiler.h>
> +#include <linux/init.h>
> +#include <linux/iommu.h>
> +#include <linux/kernel.h>
> +#include <linux/pci.h>
> +
> +#include "iommu-bits.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 rc, vec;
> +
> + rc = pcim_enable_device(pdev);
> + if (rc)
> + return rc;
> +
> + if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM))
> + return -ENODEV;
> +
> + if (pci_resource_len(pdev, 0) < RISCV_IOMMU_REG_SIZE)
> + return -ENODEV;
> +
> + rc = pcim_iomap_regions(pdev, BIT(0), pci_name(pdev));
> + if (rc)
> + return dev_err_probe(dev, rc, "pcim_iomap_regions failed\n");
> +
> + iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
> + if (!iommu)
> + return -ENOMEM;
> +
> + iommu->dev = dev;
> + iommu->reg = pcim_iomap_table(pdev)[0];
> +
> + pci_set_master(pdev);
> + dev_set_drvdata(dev, iommu);
> +
> + /* Check device reported capabilities / features. */
> + iommu->caps = riscv_iommu_readq(iommu, RISCV_IOMMU_REG_CAPABILITIES);
> + iommu->fctl = riscv_iommu_readl(iommu, RISCV_IOMMU_REG_FCTL);
> +
> + /* The PCI driver only uses MSIs, make sure the IOMMU supports this */
> + switch (FIELD_GET(RISCV_IOMMU_CAPABILITIES_IGS, iommu->caps)) {
> + case RISCV_IOMMU_CAPABILITIES_IGS_MSI:
> + case RISCV_IOMMU_CAPABILITIES_IGS_BOTH:
> + break;
> + default:
> + return dev_err_probe(dev, -ENODEV,
> + "unable to use message-signaled interrupts\n");
> + }
> +
> + /* Allocate and assign IRQ vectors for the various events */
> + rc = pci_alloc_irq_vectors(pdev, 1, RISCV_IOMMU_INTR_COUNT,
> + PCI_IRQ_MSIX | PCI_IRQ_MSI);
> + if (rc <= 0)
> + return dev_err_probe(dev, -ENODEV,
> + "unable to allocate irq vectors\n");
> +
> + iommu->irqs_count = rc;
> + for (vec = 0; vec < iommu->irqs_count; vec++)
> + iommu->irqs[vec] = msi_get_virq(dev, vec);
> +
> + /* Enable message-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_pci_remove(struct pci_dev *pdev)
> +{
> + struct riscv_iommu_device *iommu = dev_get_drvdata(&pdev->dev);
> +
> + riscv_iommu_remove(iommu);
> +}
> +
> +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,}
> +};
> +
> +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 = {
> + .suppress_bind_attrs = true,
> + },
> +};
> +
> +builtin_pci_driver(riscv_iommu_pci_driver);
> --
> 2.34.1
>
>
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