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2025-12-06Merge tag 'tsm-for-6.19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/devsec/tsm Pull PCIe Link Encryption and Device Authentication from Dan Williams: "New PCI infrastructure and one architecture implementation for PCIe link encryption establishment via platform firmware services. This work is the result of multiple vendors coming to consensus on some core infrastructure (thanks Alexey, Yilun, and Aneesh!), and three vendor implementations, although only one is included in this pull. The PCI core changes have an ack from Bjorn, the crypto/ccp/ changes have an ack from Tom, and the iommu/amd/ changes have an ack from Joerg. PCIe link encryption is made possible by the soup of acronyms mentioned in the shortlog below. Link Integrity and Data Encryption (IDE) is a protocol for installing keys in the transmitter and receiver at each end of a link. That protocol is transported over Data Object Exchange (DOE) mailboxes using PCI configuration requests. The aspect that makes this a "platform firmware service" is that the key provisioning and protocol is coordinated through a Trusted Execution Envrionment (TEE) Security Manager (TSM). That is either firmware running in a coprocessor (AMD SEV-TIO), or quasi-hypervisor software (Intel TDX Connect / ARM CCA) running in a protected CPU mode. Now, the only reason to ask a TSM to run this protocol and install the keys rather than have a Linux driver do the same is so that later, a confidential VM can ask the TSM directly "can you certify this device?". That precludes host Linux from provisioning its own keys, because host Linux is outside the trust domain for the VM. It also turns out that all architectures, save for one, do not publish a mechanism for an OS to establish keys in the root port. So "TSM-established link encryption" is the only cross-architecture path for this capability for the foreseeable future. This unblocks the other arch implementations to follow in v6.20/v7.0, once they clear some other dependencies, and it unblocks the next phase of work to implement the end-to-end flow of confidential device assignment. The PCIe specification calls this end-to-end flow Trusted Execution Environment (TEE) Device Interface Security Protocol (TDISP). In the meantime, Linux gets a link encryption facility which has practical benefits along the same lines as memory encryption. It authenticates devices via certificates and may protect against interposer attacks trying to capture clear-text PCIe traffic. Summary: - Introduce the PCI/TSM core for the coordination of device authentication, link encryption and establishment (IDE), and later management of the device security operational states (TDISP). Notify the new TSM core layer of PCI device arrival and departure - Add a low level TSM driver for the link encryption establishment capabilities of the AMD SEV-TIO architecture - Add a library of helpers TSM drivers to use for IDE establishment and the DOE transport - Add skeleton support for 'bind' and 'guest_request' operations in support of TDISP" * tag 'tsm-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/devsec/tsm: (23 commits) crypto/ccp: Fix CONFIG_PCI=n build virt: Fix Kconfig warning when selecting TSM without VIRT_DRIVERS crypto/ccp: Implement SEV-TIO PCIe IDE (phase1) iommu/amd: Report SEV-TIO support psp-sev: Assign numbers to all status codes and add new ccp: Make snp_reclaim_pages and __sev_do_cmd_locked public PCI/TSM: Add 'dsm' and 'bound' attributes for dependent functions PCI/TSM: Add pci_tsm_guest_req() for managing TDIs PCI/TSM: Add pci_tsm_bind() helper for instantiating TDIs PCI/IDE: Initialize an ID for all IDE streams PCI/IDE: Add Address Association Register setup for downstream MMIO resource: Introduce resource_assigned() for discerning active resources PCI/TSM: Drop stub for pci_tsm_doe_transfer() drivers/virt: Drop VIRT_DRIVERS build dependency PCI/TSM: Report active IDE streams PCI/IDE: Report available IDE streams PCI/IDE: Add IDE establishment helpers PCI: Establish document for PCI host bridge sysfs attributes PCI: Add PCIe Device 3 Extended Capability enumeration PCI/TSM: Establish Secure Sessions and Link Encryption ...
2025-12-04Merge tag 'vfio-v6.19-rc1' of https://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - Move libvfio selftest artifacts in preparation of more tightly coupled integration with KVM selftests (David Matlack) - Fix comment typo in mtty driver (Chu Guangqing) - Support for new hardware revision in the hisi_acc vfio-pci variant driver where the migration registers can now be accessed via the PF. When enabled for this support, the full BAR can be exposed to the user (Longfang Liu) - Fix vfio cdev support for VF token passing, using the correct size for the kernel structure, thereby actually allowing userspace to provide a non-zero UUID token. Also set the match token callback for the hisi_acc, fixing VF token support for this this vfio-pci variant driver (Raghavendra Rao Ananta) - Introduce internal callbacks on vfio devices to simplify and consolidate duplicate code for generating VFIO_DEVICE_GET_REGION_INFO data, removing various ioctl intercepts with a more structured solution (Jason Gunthorpe) - Introduce dma-buf support for vfio-pci devices, allowing MMIO regions to be exposed through dma-buf objects with lifecycle managed through move operations. This enables low-level interactions such as a vfio-pci based SPDK drivers interacting directly with dma-buf capable RDMA devices to enable peer-to-peer operations. IOMMUFD is also now able to build upon this support to fill a long standing feature gap versus the legacy vfio type1 IOMMU backend with an implementation of P2P support for VM use cases that better manages the lifecycle of the P2P mapping (Leon Romanovsky, Jason Gunthorpe, Vivek Kasireddy) - Convert eventfd triggering for error and request signals to use RCU mechanisms in order to avoid a 3-way lockdep reported deadlock issue (Alex Williamson) - Fix a 32-bit overflow introduced via dma-buf support manifesting with large DMA buffers (Alex Mastro) - Convert nvgrace-gpu vfio-pci variant driver to insert mappings on fault rather than at mmap time. This conversion serves both to make use of huge PFNMAPs but also to both avoid corrected RAS events during reset by now being subject to vfio-pci-core's use of unmap_mapping_range(), and to enable a device readiness test after reset (Ankit Agrawal) - Refactoring of vfio selftests to support multi-device tests and split code to provide better separation between IOMMU and device objects. This work also enables a new test suite addition to measure parallel device initialization latency (David Matlack) * tag 'vfio-v6.19-rc1' of https://github.com/awilliam/linux-vfio: (65 commits) vfio: selftests: Add vfio_pci_device_init_perf_test vfio: selftests: Eliminate INVALID_IOVA vfio: selftests: Split libvfio.h into separate header files vfio: selftests: Move vfio_selftests_*() helpers into libvfio.c vfio: selftests: Rename vfio_util.h to libvfio.h vfio: selftests: Stop passing device for IOMMU operations vfio: selftests: Move IOVA allocator into iova_allocator.c vfio: selftests: Move IOMMU library code into iommu.c vfio: selftests: Rename struct vfio_dma_region to dma_region vfio: selftests: Upgrade driver logging to dev_err() vfio: selftests: Prefix logs with device BDF where relevant vfio: selftests: Eliminate overly chatty logging vfio: selftests: Support multiple devices in the same container/iommufd vfio: selftests: Introduce struct iommu vfio: selftests: Rename struct vfio_iommu_mode to iommu_mode vfio: selftests: Allow passing multiple BDFs on the command line vfio: selftests: Split run.sh into separate scripts vfio: selftests: Move run.sh into scripts directory vfio/nvgrace-gpu: wait for the GPU mem to be ready vfio/nvgrace-gpu: Inform devmem unmapped after reset ...
2025-11-20PCI/P2PDMA: Document DMABUF modelJason Gunthorpe
Reflect latest changes in p2p implementation to support DMABUF lifecycle. Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Ankit Agrawal <ankita@nvidia.com> Link: https://lore.kernel.org/r/20251120-dmabuf-vfio-v9-5-d7f71607f371@nvidia.com Signed-off-by: Alex Williamson <alex@shazbot.org>
2025-11-14PCI: Move Resizable BAR code to rebar.cIlpo Järvinen
For lack of a better place to put it, Resizable BAR code has been placed inside pci.c and setup-res.c that do not use it for anything. Upcoming changes are going to add more Resizable BAR related functions, increasing the code size. As pci.c is huge as is, move the Resizable BAR related code and the BAR resize code from setup-res.c to rebar.c. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patch.msgid.link/20251113180053.27944-2-ilpo.jarvinen@linux.intel.com
2025-11-03PCI/TSM: Establish Secure Sessions and Link EncryptionDan Williams
The PCIe 7.0 specification, section 11, defines the Trusted Execution Environment (TEE) Device Interface Security Protocol (TDISP). This protocol definition builds upon Component Measurement and Authentication (CMA), and link Integrity and Data Encryption (IDE). It adds support for assigning devices (PCI physical or virtual function) to a confidential VM such that the assigned device is enabled to access guest private memory protected by technologies like Intel TDX, AMD SEV-SNP, RISCV COVE, or ARM CCA. The "TSM" (TEE Security Manager) is a concept in the TDISP specification of an agent that mediates between a "DSM" (Device Security Manager) and system software in both a VMM and a confidential VM. A VMM uses TSM ABIs to setup link security and assign devices. A confidential VM uses TSM ABIs to transition an assigned device into the TDISP "RUN" state and validate its configuration. From a Linux perspective the TSM abstracts many of the details of TDISP, IDE, and CMA. Some of those details leak through at times, but for the most part TDISP is an internal implementation detail of the TSM. CONFIG_PCI_TSM adds an "authenticated" attribute and "tsm/" subdirectory to pci-sysfs. Consider that the TSM driver may itself be a PCI driver. Userspace can watch for the arrival of a "TSM" device, /sys/class/tsm/tsm0/uevent KOBJ_CHANGE, to know when the PCI core has initialized TSM services. The operations that can be executed against a PCI device are split into two mutually exclusive operation sets, "Link" and "Security" (struct pci_tsm_{link,security}_ops). The "Link" operations manage physical link security properties and communication with the device's Device Security Manager firmware. These are the host side operations in TDISP. The "Security" operations coordinate the security state of the assigned virtual device (TDI). These are the guest side operations in TDISP. Only "link" (Secure Session and physical Link Encryption) operations are defined at this stage. There are placeholders for the device security (Trusted Computing Base entry / exit) operations. The locking allows for multiple devices to be executing commands simultaneously, one outstanding command per-device and an rwsem synchronizes the implementation relative to TSM registration/unregistration events. Thanks to Wu Hao for his work on an early draft of this support. Cc: Lukas Wunner <lukas@wunner.de> Cc: Samuel Ortiz <sameo@rivosinc.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Alexey Kardashevskiy <aik@amd.com> Co-developed-by: Xu Yilun <yilun.xu@linux.intel.com> Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com> Link: https://patch.msgid.link/20251031212902.2256310-5-dan.j.williams@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-10-21PCI/TPH: Add TPH documentationWei Huang
Add a document for the TPH feature, including description of "notph" kernel parameter and the API interface. Co-developed-by: Eric Van Tassell <Eric.VanTassell@amd.com> Link: https://lore.kernel.org/r/20241002165954.128085-4-wei.huang2@amd.com Signed-off-by: Eric Van Tassell <Eric.VanTassell@amd.com> Signed-off-by: Wei Huang <wei.huang2@amd.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com> Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com> Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
2024-02-12PCI: Move PCI-specific devres code to drivers/pci/Philipp Stanner
The pcim_*() functions in lib/devres.c are guarded by an #ifdef CONFIG_PCI and, thus, don't belong to this file. They are only ever used for PCI and are not generic infrastructure. Move all pcim_*() functions in lib/devres.c to drivers/pci/devres.c. Adjust the Makefile. Add drivers/pci/devres.c to Documentation. Link: https://lore.kernel.org/r/20240131090023.12331-4-pstanner@redhat.com Suggested-by: Danilo Krummrich <dakr@redhat.com> Signed-off-by: Philipp Stanner <pstanner@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2024-02-12PCI: Move pci_iomap.c to drivers/pci/Philipp Stanner
The entirety of pci_iomap.c is guarded by an #ifdef CONFIG_PCI. It, consequently, does not belong to lib/ because it is not generic infrastructure. Move pci_iomap.c to drivers/pci/ and implement the necessary changes to Makefiles and Kconfigs. Update MAINTAINERS file. Update Documentation. Link: https://lore.kernel.org/r/20240131090023.12331-3-pstanner@redhat.com [bhelgaas: squash in https://lore.kernel.org/r/20240212150934.24559-1-pstanner@redhat.com] Suggested-by: Danilo Krummrich <dakr@redhat.com> Signed-off-by: Philipp Stanner <pstanner@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2024-01-17Merge tag 'pci-v6.8-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci Pull pci updates from Bjorn Helgaas: "Enumeration: - Reserve ECAM so we don't assign it to PCI BARs; this works around bugs where BIOS included ECAM in a PNP0A03 host bridge window, didn't reserve it via a PNP0C02 motherboard device, and didn't allocate space for SR-IOV VF BARs (Bjorn Helgaas) - Add MMCONFIG/ECAM debug logging (Bjorn Helgaas) - Rename 'MMCONFIG' to 'ECAM' to match spec usage (Bjorn Helgaas) - Log device type (Root Port, Switch Port, etc) during enumeration (Bjorn Helgaas) - Log bridges before downstream devices so the dmesg order is more logical (Bjorn Helgaas) - Log resource names (BAR 0, VF BAR 0, bridge window, etc) consistently instead of a mix of names and "reg 0x10" (Puranjay Mohan, Bjorn Helgaas) - Fix 64GT/s effective data rate calculation to use 1b/1b encoding rather than the 8b/10b or 128b/130b used by lower rates (Ilpo Järvinen) - Use PCI_HEADER_TYPE_* instead of literals in x86, powerpc, SCSI lpfc (Ilpo Järvinen) - Clean up open-coded PCIBIOS return code mangling (Ilpo Järvinen) Resource management: - Restructure pci_dev_for_each_resource() to avoid computing the address of an out-of-bounds array element (the bounds check was performed later so the element was never actually *read*, but it's nicer to avoid even computing an out-of-bounds address) (Andy Shevchenko) Driver binding: - Convert pci-host-common.c platform .remove() callback to .remove_new() returning 'void' since it's not useful to return error codes here (Uwe Kleine-König) - Convert exynos, keystone, kirin from .remove() to .remove_new(), which returns void instead of int (Uwe Kleine-König) - Drop unused struct pci_driver.node member (Mathias Krause) Virtualization: - Add ACS quirk for more Zhaoxin Root Ports (LeoLiuoc) Error handling: - Log AER errors as "Correctable" (not "Corrected") or "Uncorrectable" to match spec terminology (Bjorn Helgaas) - Decode Requester ID when no error info found instead of printing the raw hex value (Bjorn Helgaas) Endpoint framework: - Use a unique test pattern for each BAR in the pci_endpoint_test to make it easier to debug address translation issues (Niklas Cassel) Broadcom STB PCIe controller driver: - Add DT property "brcm,clkreq-mode" and driver support for different CLKREQ# modes to make ASPM L1.x states possible (Jim Quinlan) Freescale Layerscape PCIe controller driver: - Add suspend/resume support for Layerscape LS1043a and LS1021a, including software-managed PME_Turn_Off and transitions between L0, L2/L3_Ready Link states (Frank Li) MediaTek PCIe controller driver: - Clear MSI interrupt status before handler to avoid missing MSIs that occur after the handler (qizhong cheng) MediaTek PCIe Gen3 controller driver: - Update mediatek-gen3 translation window setup to handle MMIO space that is not a power of two in size (Jianjun Wang) Qualcomm PCIe controller driver: - Increase qcom iommu-map maxItems to accommodate SDX55 (five entries) and SDM845 (sixteen entries) (Krzysztof Kozlowski) - Describe qcom,pcie-sc8180x clocks and resets accurately (Krzysztof Kozlowski) - Describe qcom,pcie-sm8150 clocks and resets accurately (Krzysztof Kozlowski) - Correct the qcom "reset-name" property, previously incorrectly called "reset-names" (Krzysztof Kozlowski) - Document qcom,pcie-sm8650, based on qcom,pcie-sm8550 (Neil Armstrong) Renesas R-Car PCIe controller driver: - Replace of_device.h with explicit of.h include to untangle header usage (Rob Herring) - Add DT and driver support for optional miniPCIe 1.5v and 3.3v regulators on KingFisher (Wolfram Sang) SiFive FU740 PCIe controller driver: - Convert fu740 CONFIG_PCIE_FU740 dependency from SOC_SIFIVE to ARCH_SIFIVE (Conor Dooley) Synopsys DesignWare PCIe controller driver: - Align iATU mapping for endpoint MSI-X (Niklas Cassel) - Drop "host_" prefix from struct dw_pcie_host_ops members (Yoshihiro Shimoda) - Drop "ep_" prefix from struct dw_pcie_ep_ops members (Yoshihiro Shimoda) - Rename struct dw_pcie_ep_ops.func_conf_select() to .get_dbi_offset() to be more descriptive (Yoshihiro Shimoda) - Add Endpoint DBI accessors to encapsulate offset lookups (Yoshihiro Shimoda) TI J721E PCIe driver: - Add j721e DT and driver support for 'num-lanes' for devices that support x1, x2, or x4 Links (Matt Ranostay) - Add j721e DT compatible strings and driver support for j784s4 (Matt Ranostay) - Make TI J721E Kconfig depend on ARCH_K3 since the hardware is specific to those TI SoC parts (Peter Robinson) TI Keystone PCIe controller driver: - Hold power management references to all PHYs while enabling them to avoid a race when one provides clocks to others (Siddharth Vadapalli) Xilinx XDMA PCIe controller driver: - Remove redundant dev_err(), since platform_get_irq() and platform_get_irq_byname() already log errors (Yang Li) - Fix uninitialized symbols in xilinx_pl_dma_pcie_setup_irq() (Krzysztof Wilczyński) - Fix xilinx_pl_dma_pcie_init_irq_domain() error return when irq_domain_add_linear() fails (Harshit Mogalapalli) MicroSemi Switchtec management driver: - Do dma_mrpc cleanup during switchtec_pci_remove() to match its devm ioremapping in switchtec_pci_probe(). Previously the cleanup was done in stdev_release(), which used stale pointers if stdev->cdev happened to be open when the PCI device was removed (Daniel Stodden) Miscellaneous: - Convert interrupt terminology from "legacy" to "INTx" to be more specific and match spec terminology (Damien Le Moal) - In dw-xdata-pcie, pci_endpoint_test, and vmd, replace usage of deprecated ida_simple_*() API with ida_alloc() and ida_free() (Christophe JAILLET)" * tag 'pci-v6.8-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (97 commits) PCI: Fix kernel-doc issues PCI: brcmstb: Configure HW CLKREQ# mode appropriate for downstream device dt-bindings: PCI: brcmstb: Add property "brcm,clkreq-mode" PCI: mediatek-gen3: Fix translation window size calculation PCI: mediatek: Clear interrupt status before dispatching handler PCI: keystone: Fix race condition when initializing PHYs PCI: xilinx-xdma: Fix error code in xilinx_pl_dma_pcie_init_irq_domain() PCI: xilinx-xdma: Fix uninitialized symbols in xilinx_pl_dma_pcie_setup_irq() PCI: rcar-gen4: Fix -Wvoid-pointer-to-enum-cast error PCI: iproc: Fix -Wvoid-pointer-to-enum-cast warning PCI: dwc: Add dw_pcie_ep_{read,write}_dbi[2] helpers PCI: dwc: Rename .func_conf_select to .get_dbi_offset in struct dw_pcie_ep_ops PCI: dwc: Rename .ep_init to .init in struct dw_pcie_ep_ops PCI: dwc: Drop host prefix from struct dw_pcie_host_ops members misc: pci_endpoint_test: Use a unique test pattern for each BAR PCI: j721e: Make TI J721E depend on ARCH_K3 PCI: j721e: Add TI J784S4 PCIe configuration PCI/AER: Use explicit register sizes for struct members PCI/AER: Decode Requester ID when no error info found PCI/AER: Use 'Correctable' and 'Uncorrectable' spec terms for errors ...
2023-11-20PCI/P2PDMA: Remove reference to pci_p2pdma_map_sg()Tadeusz Struk
Update Documentation/driver-api/pci/p2pdma.rst doc and remove references to obsolete p2pdma mapping functions. Fixes: 0d06132fc84b ("PCI/P2PDMA: Remove pci_p2pdma_[un]map_sg()") Link: https://lore.kernel.org/r/20231113180325.444692-1-tstruk@gmail.com Signed-off-by: Tadeusz Struk <tstruk@gigaio.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Cc: stable@kernel.org
2023-11-17docs: driver-api: properly format ToC headingsVegard Nossum
"class:: toc-title" was a workaround for older Sphinx versions that are no longer supported. The canonical way to add a heading to the ToC is to use :caption:. Do that. Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: SeongJae Park <sj@kernel.org> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Armin Wolf <W_Armin@gmx.de> Cc: Iwona Winiarska <iwona.winiarska@intel.com> Cc: Ricardo Cañuelo <ricardo.canuelo@collabora.com> Cc: Tomas Winkler <tomas.winkler@intel.com> Cc: linux-media@vger.kernel.org Cc: Yanteng Si <siyanteng@loongson.cn> Cc: Alex Shi <alexs@kernel.org> Cc: Wu XiangCheng <bobwxc@email.cn> Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20231027081830.195056-7-vegard.nossum@oracle.com
2021-12-09PCI/MSI: Move code into a separate directoryThomas Gleixner
msi.c is getting larger and really could do with a splitup. Move it into its own directory to prepare for that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20211206210224.655043033@linutronix.de
2019-04-08Documentation: Kill all references to mmiowb()Will Deacon
The guarantees provided by mmiowb() are now provided implicitly by spin_unlock(), so remove all references to this most confusing of barriers from our Documentation. Good riddance. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-11PCI/P2PDMA: Clean up documentation and kernel-docRandy Dunlap
Fix typos, spellos, and grammar in p2pdma.rst and p2pdma.c. Fix return value(s) in function pci_p2pmem_alloc_sgl(). Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Logan Gunthorpe <logang@deltatee.com> Cc: Jonathan Corbet <corbet@lwn.net>
2018-10-17PCI/P2PDMA: Add P2P DMA driver writer's documentationLogan Gunthorpe
Add a restructured text file describing how to write drivers with support for P2P DMA transactions. The document describes how to use the APIs that were added in the previous few commits. Also adds an index for the PCI documentation tree even though this is the only PCI document that has been converted to restructured text at this time. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Jonathan Corbet <corbet@lwn.net>
2018-10-17docs-rst: Add a new directory for PCI documentationLogan Gunthorpe
Add a new directory in the driver API guide for PCI-specific documentation. This is in preparation for adding a new PCI P2P DMA driver writers guide which will go in this directory. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Vinod Koul <vinod.koul@intel.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Thierry Reding <treding@nvidia.com> Cc: Sanyog Kale <sanyog.r.kale@intel.com> Cc: Sagar Dharia <sdharia@codeaurora.org>