3397c3cd85
This patch introduces a new UIO driver, uio_pci_generic_sva, which extends the functionality of uio_pci_generic by adding support for Shared Virtual Addressing (SVA) when IOMMU is enabled in the system. The key enhancement allows PCI devices to directly use user-space virtual addresses for DMA operations, eliminating the need for bounce buffers or explicit IOVA mapping. This is achieved by leveraging the kernel's IOMMU-SVA subsystem, including process address space attachment, page fault handling, and shared context management between CPU and device. With this driver, userspace applications can perform zero-copy DMA using native pointers: void *addr = malloc(N); set_dma_addr((uint64_t)addr); // Passing user VA directly start_dma(); The device can now access 'addr' through the IOMMU's PASID-based translation, provided that the underlying IOMMU hardware (e.g., Intel VT-d 3.1+, AMD-Vi, ARM SMMU, RISCV IOMMU) and platform support SVA. Dependencies: - CONFIG_IOMMU_SVA must be enabled. - The platform must support PRI (Page Request Interface) and PASID. - Device drivers/userspace must handle page faults if demand-paging is used. The implementation reuses core logic from uio_pci_generic.c while adding PASID setting, and integration with the IOMMU SVA APIs. Also, add a read-only sysfs attribute 'pasid' to expose the Process Address Space ID assigned by IOMMU driver when binding an SVA-enabled device. For details, refer to the ABI documentation for uio_pci_sva driver sysfs attribute (Documentation/ABI/testing/sysfs-driver-uio_pci_sva-pasid). Signed-off-by: Yaxing Guo <guoyaxing@bosc.ac.cn> Link: https://patch.msgid.link/20250926095828.506-1-guoyaxing@bosc.ac.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .pylintrc | ||
| .rustfmt.toml | ||
| COPYING | ||
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| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.