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path: root/arch/s390/pci/pci_bus.c
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2025-06-17s390: Remove unnecessary include <linux/export.h>Heiko Carstens
Remove include <linux/export.h> from all files which do not contain an EXPORT_SYMBOL(). See commit 7d95680d64ac ("scripts/misc-check: check unnecessary #include <linux/export.h> when W=1") for more details. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-03-31s390/pci: Fix dev.dma_range_map missing sentinel elementNiklas Schnelle
The fixed commit sets up dev.dma_range_map but missed that this is supposed to be an array of struct bus_dma_region with a sentinel element with the size field set to 0 at the end. This would lead to overruns in e.g. dma_range_map_min(). It could also result in wrong translations instead of DMA_MAPPING_ERROR in translate_phys_to_dma() if the paddr were to not fit in the aperture. Fix this by using the dma_direct_set_offset() helper which creates a sentinel for us. Fixes: d236843a6964 ("s390/pci: store DMA offset in bus_dma_region") Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Link: https://lore.kernel.org/r/20250312-fix_dma_map_alloc-v2-1-530108d9de21@linux.ibm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2025-03-31s390/pci: Fix zpci_bus_is_isolated_vf() for non-VFsNiklas Schnelle
For non-VFs, zpci_bus_is_isolated_vf() should return false because they aren't VFs. While zpci_iov_find_parent_pf() specifically checks if a function is a VF, it then simply returns that there is no parent. The simplistic check for a parent then leads to these functions being confused with isolated VFs and isolating them on their own domain even if sibling PFs should share the domain. Fix this by explicitly checking if a function is not a VF. Note also that at this point the case where RIDs are ignored is already handled and in this case all PCI functions get isolated by being detected in zpci_bus_is_multifunction_root(). Cc: stable@vger.kernel.org Fixes: 2844ddbd540f ("s390/pci: Fix handling of isolated VFs") Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2025-02-21s390/pci: store DMA offset in bus_dma_regionMatthew Rosato
PCI devices on s390 have a DMA offset that is reported via CLP. In preparation for allowing identity domains, setup the bus_dma_region for all PCI devices using the reported CLP value. Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Tested-by: Niklas Schnelle <schnelle@linux.ibm.com> Link: https://lore.kernel.org/r/20250212213418.182902-3-mjrosato@linux.ibm.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-02-11s390/pci: Fix handling of isolated VFsNiklas Schnelle
In contrast to the commit message of the fixed commit VFs whose parent PF is not configured are not always isolated, that is put on their own PCI domain. This is because for VFs to be added to an existing PCI domain it is enough for that PCI domain to share the same topology ID or PCHID. Such a matching PCI domain without a parent PF may exist when a PF from the same PCI card created the domain with the VF being a child of a different, non accessible, PF. While not causing technical issues it makes the rules which VFs are isolated inconsistent. Fix this by explicitly checking that the parent PF exists on the PCI domain determined by the topology ID or PCHID before registering the VF. This works because a parent PF which is under control of this Linux instance must be enabled and configured at the point where its child VFs appear because otherwise SR-IOV could not have been enabled on the parent. Fixes: 25f39d3dcb48 ("s390/pci: Ignore RID for isolated VFs") Cc: stable@vger.kernel.org Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2025-01-26s390/pci: Fix SR-IOV for PFs initially in standbyNiklas Schnelle
Since commit 25f39d3dcb48 ("s390/pci: Ignore RID for isolated VFs") PFs which are not initially configured but in standby are considered isolated. That is they create only a single function PCI domain. Due to the PCI domains being created on discovery, this means that even if they are configured later on, sibling PFs and their child VFs will not be added to their PCI domain breaking SR-IOV expectations. The reason the referenced commit ignored standby PFs for the creation of multi-function PCI subhierarchies, was to work around a PCI domain renumbering scenario on reboot. The renumbering would occur after removing a previously in standby PF, whose domain number is used for its configured sibling PFs and their child VFs, but which itself remained in standby. When this is followed by a reboot, the sibling PF is used instead to determine the PCI domain number of it and its child VFs. In principle it is not possible to know which standby PFs will be configured later and which may be removed. The PCI domain and root bus are pre-requisites for hotplug slots so the decision of which functions belong to which domain can not be postponed. With the renumbering occurring only in rare circumstances and being generally benign, accept it as an oddity and fix SR-IOV for initially standby PFs simply by allowing them to create PCI domains. Cc: stable@vger.kernel.org Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com> Fixes: 25f39d3dcb48 ("s390/pci: Ignore RID for isolated VFs") Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-11-26Merge tag 'pci-v6.13-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci Pull PCI updates from Bjorn Helgaas: "Enumeration: - Make pci_stop_dev() and pci_destroy_dev() safe so concurrent callers can't stop a device multiple times, even as we migrate from the global pci_rescan_remove_lock to finer-grained locking (Keith Busch) - Improve pci_walk_bus() implementation by making it recursive and moving locking up to avoid need for a 'locked' parameter (Keith Busch) - Unexport pci_walk_bus_locked(), which is only used internally by the PCI core (Keith Busch) - Detect some Thunderbolt chips that are built-in and hence 'trustworthy' by a heuristic since the 'ExternalFacingPort' and 'usb4-host-interface' ACPI properties are not quite enough (Esther Shimanovich) Resource management: - Use PCI bus addresses (not CPU addresses) in 'ranges' properties when building dynamic DT nodes so systems where PCI and CPU addresses differ work correctly (Andrea della Porta) - Tidy resource sizing and assignment with helpers to reduce redundancy (Ilpo Järvinen) - Improve pdev_sort_resources() 'bogus alignment' warning to be more specific (Ilpo Järvinen) Driver binding: - Convert driver .remove_new() callbacks to .remove() again to finish the conversion from returning 'int' to being 'void' (Sergio Paracuellos) - Export pcim_request_all_regions(), a managed interface to request all BARs (Philipp Stanner) - Replace pcim_iomap_regions_request_all() with pcim_request_all_regions(), and pcim_iomap_table()[n] with pcim_iomap(n), in the following drivers: ahci, crypto qat, crypto octeontx2, intel_th, iwlwifi, ntb idt, serial rp2, ALSA korg1212 (Philipp Stanner) - Remove the now unused pcim_iomap_regions_request_all() (Philipp Stanner) - Export pcim_iounmap_region(), a managed interface to unmap and release a PCI BAR (Philipp Stanner) - Replace pcim_iomap_regions(mask) with pcim_iomap_region(n), and pcim_iounmap_regions(mask) with pcim_iounmap_region(n), in the following drivers: fpga dfl-pci, block mtip32xx, gpio-merrifield, cavium (Philipp Stanner) Error handling: - Add sysfs 'reset_subordinate' to reset the entire hierarchy below a bridge; previously Secondary Bus Reset could only be used when there was a single device below a bridge (Keith Busch) - Warn if we reset a running device where the driver didn't register pci_error_handlers notification callbacks (Keith Busch) ASPM: - Disable ASPM L1 before touching L1 PM Substates to follow the spec closer and avoid a CPU load timeout on some platforms (Ajay Agarwal) - Set devices below Intel VMD to D0 before enabling ASPM L1 Substates as required per spec for all L1 Substates changes (Jian-Hong Pan) Power management: - Enable starfive controller runtime PM before probing host bridge (Mayank Rana) - Enable runtime power management for host bridges (Krishna chaitanya chundru) Power control: - Use of_platform_device_create() instead of of_platform_populate() to create pwrctl platform devices so we can control it based on the child nodes (Manivannan Sadhasivam) - Create pwrctrl platform devices only if there's a relevant power supply property (Manivannan Sadhasivam) - Add device link from the pwrctl supplier to the PCI dev to ensure pwrctl drivers are probed before the PCI dev driver; this avoids a race where pwrctl could change device power state while the PCI driver was active (Manivannan Sadhasivam) - Find pwrctl device for removal with of_find_device_by_node() instead of searching all children of the parent (Manivannan Sadhasivam) - Rename 'pwrctl' to 'pwrctrl' to match new bandwidth controller ('bwctrl') and hotplug files (Bjorn Helgaas) Bandwidth control: - Add read/modify/write locking for Link Control 2, which is used to manage Link speed (Ilpo Järvinen) - Extract Link Bandwidth Management Status check into pcie_lbms_seen(), where it can be shared between the bandwidth controller and quirks that use it to help retrain failed links (Ilpo Järvinen) - Re-add Link Bandwidth notification support with updates to address the reasons it was previously reverted (Alexandru Gagniuc, Ilpo Järvinen) - Add pcie_set_target_speed() and related functionality so drivers can manage PCIe Link speed based on thermal or other constraints (Ilpo Järvinen) - Add a thermal cooling driver to throttle PCIe Links via the existing thermal management framework (Ilpo Järvinen) - Add a userspace selftest for the PCIe bandwidth controller (Ilpo Järvinen) PCI device hotplug: - Add hotplug controller driver for Marvell OCTEON multi-function device where function 0 has a management console interface to enable/disable and provision various personalities for the other functions (Shijith Thotton) - Retain a reference to the pci_bus for the lifetime of a pci_slot to avoid a use-after-free when the thunderbolt driver resets USB4 host routers on boot, causing hotplug remove/add of downstream docks or other devices (Lukas Wunner) - Remove unused cpcihp struct cpci_hp_controller_ops.hardware_test (Guilherme Giacomo Simoes) - Remove unused cpqphp struct ctrl_dbg.ctrl (Christophe JAILLET) - Use pci_bus_read_dev_vendor_id() instead of hand-coded presence detection in cpqphp (Ilpo Järvinen) - Simplify cpqphp enumeration, which is already simple-minded and doesn't handle devices below hot-added bridges (Ilpo Järvinen) Virtualization: - Add ACS quirk for Wangxun FF5xxx NICs, which don't advertise an ACS capability but do isolate functions as though PCI_ACS_RR and PCI_ACS_CR were set, so the functions can be in independent IOMMU groups (Mengyuan Lou) TLP Processing Hints (TPH): - Add and document TLP Processing Hints (TPH) support so drivers can enable and disable TPH and the kernel can save/restore TPH configuration (Wei Huang) - Add TPH Steering Tag support so drivers can retrieve Steering Tag values associated with specific CPUs via an ACPI _DSM to improve performance by directing DMA writes closer to their consumers (Wei Huang) Data Object Exchange (DOE): - Wait up to 1 second for DOE Busy bit to clear before writing a request to the mailbox to avoid failures if the mailbox is still busy from a previous transfer (Gregory Price) Endpoint framework: - Skip attempts to allocate from endpoint controller memory window if the requested size is larger than the window (Damien Le Moal) - Add and document pci_epc_mem_map() and pci_epc_mem_unmap() to handle controller-specific size and alignment constraints, and add test cases to the endpoint test driver (Damien Le Moal) - Implement dwc pci_epc_ops.align_addr() so pci_epc_mem_map() can observe DWC-specific alignment requirements (Damien Le Moal) - Synchronously cancel command handler work in endpoint test before cleaning up DMA and BARs (Damien Le Moal) - Respect endpoint page size in dw_pcie_ep_align_addr() (Niklas Cassel) - Use dw_pcie_ep_align_addr() in dw_pcie_ep_raise_msi_irq() and dw_pcie_ep_raise_msix_irq() instead of open coding the equivalent (Niklas Cassel) - Avoid NULL dereference if Modem Host Interface Endpoint lacks 'mmio' DT property (Zhongqiu Han) - Release PCI domain ID of Endpoint controller parent (not controller itself) and before unregistering the controller, to avoid use-after-free (Zijun Hu) - Clear secondary (not primary) EPC in pci_epc_remove_epf() when removing the secondary controller associated with an NTB (Zijun Hu) Cadence PCIe controller driver: - Lower severity of 'phy-names' message (Bartosz Wawrzyniak) Freescale i.MX6 PCIe controller driver: - Fix suspend/resume support on i.MX6QDL, which has a hardware erratum that prevents use of L2 (Stefan Eichenberger) Intel VMD host bridge driver: - Add 0xb60b and 0xb06f Device IDs for client SKUs (Nirmal Patel) MediaTek PCIe Gen3 controller driver: - Update mediatek-gen3 DT binding to require the exact number of clocks for each SoC (Fei Shao) - Add support for DT 'max-link-speed' and 'num-lanes' properties to restrict the link speed and width (AngeloGioacchino Del Regno) Microchip PolarFlare PCIe controller driver: - Add DT and driver support for using either of the two PolarFire Root Ports (Conor Dooley) NVIDIA Tegra194 PCIe controller driver: - Move endpoint controller cleanups that depend on refclk from the host to the notifier that tells us the host has deasserted PERST#, when refclk should be valid (Manivannan Sadhasivam) Qualcomm PCIe controller driver: - Add qcom SAR2130P DT binding with an additional clock (Dmitry Baryshkov) - Enable MSI interrupts if 'global' IRQ is supported, since a previous commit unintentionally masked them (Manivannan Sadhasivam) - Move endpoint controller cleanups that depend on refclk from the host to the notifier that tells us the host has deasserted PERST#, when refclk should be valid (Manivannan Sadhasivam) - Add DT binding and driver support for IPQ9574, with Synopsys IP v5.80a and Qcom IP 1.27.0 (devi priya) - Move the OPP "operating-points-v2" table from the qcom,pcie-sm8450.yaml DT binding to qcom,pcie-common.yaml, where it can be used by other Qcom platforms (Qiang Yu) - Add 'global' SPI interrupt for events like link-up, link-down to qcom,pcie-x1e80100 DT binding so we can start enumeration when the link comes up (Qiang Yu) - Disable ASPM L0s for qcom,pcie-x1e80100 since the PHY is not tuned to support this (Qiang Yu) - Add ops_1_21_0 for SC8280X family SoC, which doesn't use the 'iommu-map' DT property and doesn't need BDF-to-SID translation (Qiang Yu) Rockchip PCIe controller driver: - Define ROCKCHIP_PCIE_AT_SIZE_ALIGN to replace magic 256 endpoint .align value (Damien Le Moal) - When unmapping an endpoint window, compute the region index instead of searching for it, and verify that the address was mapped (Damien Le Moal) - When mapping an endpoint window, verify that the address hasn't been mapped already (Damien Le Moal) - Implement pci_epc_ops.align_addr() for rockchip-ep (Damien Le Moal) - Fix MSI IRQ data mapping to observe the alignment constraint, which fixes intermittent page faults in memcpy_toio() and memcpy_fromio() (Damien Le Moal) - Rename rockchip_pcie_parse_ep_dt() to rockchip_pcie_ep_get_resources() for consistency with similar DT interfaces (Damien Le Moal) - Skip the unnecessary link train in rockchip_pcie_ep_probe() and do it only in the endpoint start operation (Damien Le Moal) - Implement pci_epc_ops.stop_link() to disable link training and controller configuration (Damien Le Moal) - Attempt link training at 5 GT/s when both partners support it (Damien Le Moal) - Add a handler for PERST# signal so we can detect host-initiated resets and start link training after PERST# is deasserted (Damien Le Moal) Synopsys DesignWare PCIe controller driver: - Clear outbound address on unmap so dw_pcie_find_index() won't match an ATU index that was already unmapped (Damien Le Moal) - Use of_property_present() instead of of_property_read_bool() when testing for presence of non-boolean DT properties (Rob Herring) - Advertise 1MB size if endpoint supports Resizable BARs, which was inadvertently lost in v6.11 (Niklas Cassel) TI J721E PCIe driver: - Add PCIe support for J722S SoC (Siddharth Vadapalli) - Delay PCIE_T_PVPERL_MS (100 ms), not just PCIE_T_PERST_CLK_US (100 us), before deasserting PERST# to ensure power and refclk are stable (Siddharth Vadapalli) TI Keystone PCIe controller driver: - Set the 'ti,keystone-pcie' mode so v3.65a devices work in Root Complex mode (Kishon Vijay Abraham I) - Try to avoid unrecoverable SError for attempts to issue config transactions when the link is down; this is racy but the best we can do (Kishon Vijay Abraham I) Miscellaneous: - Reorganize kerneldoc parameter names to match order in function signature (Julia Lawall) - Fix sysfs reset_method_store() memory leak (Todd Kjos) - Simplify pci_create_slot() (Ilpo Järvinen) - Fix incorrect printf format specifiers in pcitest (Luo Yifan)" * tag 'pci-v6.13-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (127 commits) PCI: rockchip-ep: Handle PERST# signal in EP mode PCI: rockchip-ep: Improve link training PCI: rockship-ep: Implement the pci_epc_ops::stop_link() operation PCI: rockchip-ep: Refactor endpoint link training enable PCI: rockchip-ep: Refactor rockchip_pcie_ep_probe() MSI-X hiding PCI: rockchip-ep: Refactor rockchip_pcie_ep_probe() memory allocations PCI: rockchip-ep: Rename rockchip_pcie_parse_ep_dt() PCI: rockchip-ep: Fix MSI IRQ data mapping PCI: rockchip-ep: Implement the pci_epc_ops::align_addr() operation PCI: rockchip-ep: Improve rockchip_pcie_ep_map_addr() PCI: rockchip-ep: Improve rockchip_pcie_ep_unmap_addr() PCI: rockchip-ep: Use a macro to define EP controller .align feature PCI: rockchip-ep: Fix address translation unit programming PCI/pwrctrl: Rename pwrctrl functions and structures PCI/pwrctrl: Rename pwrctl files to pwrctrl PCI/pwrctl: Remove pwrctl device without iterating over all children of pwrctl parent PCI/pwrctl: Ensure that pwrctl drivers are probed before PCI client drivers PCI/pwrctl: Create pwrctl device only if at least one power supply is present PCI/pwrctl: Use of_platform_device_create() to create pwrctl devices tools: PCI: Fix incorrect printf format specifiers ...
2024-10-18PCI: Remove unused PCI_SUBTRACTIVE_DECODEIlpo Järvinen
2fe2abf896c1 ("PCI: augment bus resource table with a list") added PCI_SUBTRACTIVE_DECODE which is put into the struct pci_bus_resource flags field but is never read. There seems to never have been users for it. Remove both PCI_SUBTRACTIVE_DECODE and the flags field from the struct pci_bus_resource. Link: https://lore.kernel.org/r/20241017141111.44612-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2024-10-10s390/pci: Ignore RID for isolated VFsNiklas Schnelle
Ensure that VFs used in isolation, that is with their parent PF not visible to the configuration but with their RID exposed, are treated compatibly with existing isolated VF use cases without exposed RID including RoCE Express VFs. This allows creating configurations where one LPAR manages PFs while their child VFs are used by other LPARs. This gives the LPAR managing the PFs a role analogous to that of the hypervisor in a typical use case of passing child VFs to guests. Instead of creating a multifunction struct zpci_bus whenever a PCI function with RID exposed is discovered only create such a bus for configured physical functions and only consider multifunction busses when searching for an existing bus. Additionally only set zdev->devfn to the devfn part of the RID once the function is added to a multifunction bus. This also fixes probing of more than 7 such isolated VFs from the same physical bus. This is because common PCI code in pci_scan_slot() only looks for more functions when pdev->multifunction is set which somewhat counter intutively is not the case for VFs. Note that PFs are looked at before their child VFs is guaranteed because we sort the zpci_list by RID ascending. Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-10s390/pci: Use topology ID for multi-function devicesNiklas Schnelle
The newly introduced topology ID (TID) field in the CLP Query PCI Function explicitly identifies groups of PCI functions whose RIDs belong to the same (sub-)topology. When available use the TID instead of the PCHID to match zPCI busses/domains for multi-function devices. Note that currently only a single PCI bus per TID is supported. This change is required because in future machines the PCHID will not identify a PCI card but a specific port in the case of some multi-port NICs while from a PCI point of view the entire card is a subtopology. Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-10-02s390/pci: Use dma-iommu layerNiklas Schnelle
While s390 already has a standard IOMMU driver and previous changes have added I/O TLB flushing operations this driver is currently only used for user-space PCI access such as vfio-pci. For the DMA API s390 instead utilizes its own implementation in arch/s390/pci/pci_dma.c which drives the same hardware and shares some code but requires a complex and fragile hand over between DMA API and IOMMU API use of a device and despite code sharing still leads to significant duplication and maintenance effort. Let's utilize the common code DMAP API implementation from drivers/iommu/dma-iommu.c instead allowing us to get rid of arch/s390/pci/pci_dma.c. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Link: https://lore.kernel.org/r/20230928-dma_iommu-v13-3-9e5fc4dacc36@linux.ibm.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-04-04Merge branch 'uaccess-inline-asm-cleanup' into featuresVasily Gorbik
Heiko Carstens says: =================== There are a couple of oddities within the s390 uaccess library functions. Therefore cleanup the whole uaccess.c file. There is no functional change, only improved readability. The output of "objdump -Dr" was always compared before/after each patch to make sure that the generated object file is identical, if that could be expected. Therefore the series also includes more patches than really required to cleanup the code. Furthermore the kunit usercopy tests also still pass. =================== Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-03-13s390/pci: clean up left over special treatment for function zeroNiklas Schnelle
Prior to commit 960ac3626487 ("s390/pci: allow zPCI zbus without a function zero") enabling and scanning a PCI function had to potentially be postponed until the function with devfn zero on that bus was plugged. While the commit removed the waiting itself extra code to scan all functions on the PCI bus once function zero appeared was missed. Remove that code and the outdated comments about waiting for function zero. Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/20230306151014.60913-5-schnelle@linux.ibm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-03-13s390/pci: remove redundant pci_bus_add_devices() on new busNiklas Schnelle
The pci_bus_add_devices() call in zpci_bus_create_pci_bus() is without function since at this point no device could have been added to the freshly created PCI bus. Suggested-by: Bjorn Helgaas <helgaas@kernel.org> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/20230306151014.60913-4-schnelle@linux.ibm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-03-13s390/pci: only add specific device in zpci_bus_scan_device()Niklas Schnelle
As the name suggests zpci_bus_scan_device() is used to scan a specific device and thus pci_bus_add_device() for that device is sufficient. Furthermore move this call inside the rescan/remove locking. Suggested-by: Bjorn Helgaas <helgaas@kernel.org> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/20230306151014.60913-3-schnelle@linux.ibm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-03-13PCI: s390: Fix use-after-free of PCI resources with per-function hotplugNiklas Schnelle
On s390 PCI functions may be hotplugged individually even when they belong to a multi-function device. In particular on an SR-IOV device VFs may be removed and later re-added. In commit a50297cf8235 ("s390/pci: separate zbus creation from scanning") it was missed however that struct pci_bus and struct zpci_bus's resource list retained a reference to the PCI functions MMIO resources even though those resources are released and freed on hot-unplug. These stale resources may subsequently be claimed when the PCI function re-appears resulting in use-after-free. One idea of fixing this use-after-free in s390 specific code that was investigated was to simply keep resources around from the moment a PCI function first appeared until the whole virtual PCI bus created for a multi-function device disappears. The problem with this however is that due to the requirement of artificial MMIO addreesses (address cookies) extra logic is then needed to keep the address cookies compatible on re-plug. At the same time the MMIO resources semantically belong to the PCI function so tying their lifecycle to the function seems more logical. Instead a simpler approach is to remove the resources of an individually hot-unplugged PCI function from the PCI bus's resource list while keeping the resources of other PCI functions on the PCI bus untouched. This is done by introducing pci_bus_remove_resource() to remove an individual resource. Similarly the resource also needs to be removed from the struct zpci_bus's resource list. It turns out however, that there is really no need to add the MMIO resources to the struct zpci_bus's resource list at all and instead we can simply use the zpci_bar_struct's resource pointer directly. Fixes: a50297cf8235 ("s390/pci: separate zbus creation from scanning") Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20230306151014.60913-2-schnelle@linux.ibm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-07-22s390/pci: allow zPCI zbus without a function zeroNiklas Schnelle
Currently the zPCI code blocks PCI bus creation and probing of a zPCI zbus unless there is a PCI function with devfn 0. This is always the case for the PCI functions with hidden RID, but may keep PCI functions from a multi-function PCI device with RID information invisible until the function 0 becomes visible. Worse, as a PCI bus is necessary to even present a PCI hotplug slot, even that remains invisible. With the probing of these so-called isolated PCI functions enabled for s390 in common code, this restriction is no longer necessary. On network cards with multiple ports and a PF per port this also allows using each port on its own while still providing the physical PCI topology information in the devfn needed to associate VFs with their parent PF. Link: https://lore.kernel.org/r/20220628143100.3228092-6-schnelle@linux.ibm.com Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
2021-08-25s390/pci: improve DMA translation init and exitNiklas Schnelle
Currently zpci_dma_init_device()/zpci_dma_exit_device() is called as part of zpci_enable_device()/zpci_disable_device() and errors for zpci_dma_exit_device() are always ignored even if we could abort. Improve upon this by moving zpci_dma_exit_device() out of zpci_disable_device() and check for errors whenever we have a way to abort the current operation. Note that for example in zpci_event_hard_deconfigured() the device is expected to be gone so we really can't abort and proceed even in case of error. Similarly move the cc == 3 special case out of zpci_unregister_ioat() and into the callers allowing to abort when finding an already disabled devices precludes proceeding with the operation. While we are at it log IOAT register/unregister errors in the s390 debugfs log, Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-08-25s390/pci: reset zdev->zbus on registration failureNiklas Schnelle
On failure to register a struct zpci_dev with a struct zpci_bus we left a dangling pointer in zdev->zbus. As zpci_create_device() bails if zpci_bus_device_register() fails this is of no consequence but still bad practice. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-04-12s390/pci: separate zbus registration from scanningNiklas Schnelle
Now that the zbus can be created without being scanned we can go one step further and make registering a device to a zbus independent from scanning it. This way the zbus handling becomes much more natural in that functions can be registered on the zbus to be scanned later more closely resembling the handling of both real PCI hardware and other virtual PCI busses like Hyper-V's virtual PCI bus (see for example drivers/pci/controller/pci-hyperv.c:create_root_hv_pci_bus()). Having zbus registration separate from scanning allows us to return fully initialized but still disabled zdevs from zpci_create_device() which can then be configured just as we would configure a zdev from standby (minus the SCLP Configure already done by the platform). There is still the exception that a PCI function with non-zero devfn can be plugged before its PCI bus, which depends on the function with zero devfn, is created. In this case the zdev returend from zpci_create_device() is still missing its bus, hotplug slot, and resources which need to be created later but at least it doesn't wait in the enabled state and can otherwise be treated as initialized. With this we also separate the initial PCI scan using CLP List PCI Functions into two phases. In the CLP loop's callback we only register each function with a virtual zbus creating the latter as needed. Then, after we have built this virtual PCI topology based on our list of zbusses, we can make use of the common code functionality to scan each complete zbus as a separate child bus. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Acked-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-04-12s390/pci: use mutex not spinlock for zbus listNiklas Schnelle
In a later change we will first collect all PCI functions from the CLP List PCI functions call, then register them to/creating the relevant zbus. Then only after we've created our virtual bus structure will we scan all zbusses iterating over the zbus list. Since scanning is relatively slow a spinlock is a bad fit for protecting the loop over the devices on the zbus. Furthermore doing the probing on the bus we need to use pci_lock_rescan_remove() as devices are added to the PCI subsystem and that is a mutex which can't be locked nested inside a spinlock section. Note that the contention of this lock should be very low either way as zbusses are only added/removed concurrently on hotplug events. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-04-12s390/pci: separate zbus creation from scanningNiklas Schnelle
In the existing code the creation of the PCI bus and the scanning of function zero all happens in zpci_scan_bus(). This in turn requires functions to be enabled and their resources to be available before the PCI bus is even created. This not only means that functions are enabled long before they are actually made available to the common PCI subsystem. In case of functions with non-zero devfn which appeared before the function with devfn zero they can wait arbitrarily long in this enabled but not scanned state. Fix this by separating the creation of the PCI bus from scanning it and only prepare, that is enable and setup MMIO bus resources, functions just before they are scanned. As they may be scanned multiple times track if we already created resources in the zdev. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Acked-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-04-12s390/pci: do more bus setup in zpci_bus_scan()Niklas Schnelle
Pull setting the maximum bus speed and multifunction attribute into zpci_bus_scan() in preparation for handling bus creation separately from scanning the bus. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Acked-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-04-12s390/pci: introduce zpci_bus_scan_device()Niklas Schnelle
To match zpci_bus_scan_device() and the PCI common code terminology and to remove some code duplication, we pull the multiple uses of pci_scan_single_device() into a function. For now this has the side effect of adding each device to the PCI bus separately and locking and unlocking the rescan/remove lock for each instead of just once per bus. This is clearly less efficient but provides a correct intermediate behavior until a follow on change does both the adding and scanning only once per bus. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Acked-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-03-22s390/pci: move zpci_remove_device() to bus codeNiklas Schnelle
The zpci_remove_device() function removes the device from the PCI common code core which is an operation dealing primarily with the zbus and PCI bus code. With that and to match an upcoming refactoring of the symmetric scanning part move it to the bus code. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-22Merge tag 'vfio-v5.10-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - New fsl-mc vfio bus driver supporting userspace drivers of objects within NXP's DPAA2 architecture (Diana Craciun) - Support for exposing zPCI information on s390 (Matthew Rosato) - Fixes for "detached" VFs on s390 (Matthew Rosato) - Fixes for pin-pages and dma-rw accesses (Yan Zhao) - Cleanups and optimize vconfig regen (Zenghui Yu) - Fix duplicate irq-bypass token registration (Alex Williamson) * tag 'vfio-v5.10-rc1' of git://github.com/awilliam/linux-vfio: (30 commits) vfio iommu type1: Fix memory leak in vfio_iommu_type1_pin_pages vfio/pci: Clear token on bypass registration failure vfio/fsl-mc: fix the return of the uninitialized variable ret vfio/fsl-mc: Fix the dead code in vfio_fsl_mc_set_irq_trigger vfio/fsl-mc: Fixed vfio-fsl-mc driver compilation on 32 bit MAINTAINERS: Add entry for s390 vfio-pci vfio-pci/zdev: Add zPCI capabilities to VFIO_DEVICE_GET_INFO vfio/fsl-mc: Add support for device reset vfio/fsl-mc: Add read/write support for fsl-mc devices vfio/fsl-mc: trigger an interrupt via eventfd vfio/fsl-mc: Add irq infrastructure for fsl-mc devices vfio/fsl-mc: Added lock support in preparation for interrupt handling vfio/fsl-mc: Allow userspace to MMAP fsl-mc device MMIO regions vfio/fsl-mc: Implement VFIO_DEVICE_GET_REGION_INFO ioctl call vfio/fsl-mc: Implement VFIO_DEVICE_GET_INFO ioctl vfio/fsl-mc: Scan DPRC objects on vfio-fsl-mc driver bind vfio: Introduce capability definitions for VFIO_DEVICE_GET_INFO s390/pci: track whether util_str is valid in the zpci_dev s390/pci: stash version in the zpci_dev vfio/fsl-mc: Add VFIO framework skeleton for fsl-mc devices ...
2020-09-22s390/pci: Mark all VFs as not implementing PCI_COMMAND_MEMORYMatthew Rosato
For s390 we can have VFs that are passed-through without the associated PF. Firmware provides an emulation layer to allow these devices to operate independently, but is missing emulation of the Memory Space Enable bit. For these as well as linked VFs, set no_command_memory which specifies these devices do not implement PCI_COMMAND_MEMORY. Fixes: abafbc551fdd ("vfio-pci: Invalidate mmaps and block MMIO access on disabled memory") Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-09-14s390/pci: consolidate SR-IOV specific codeNiklas Schnelle
currently we have multiple #ifdef CONFIG_PCI_IOV blocks spread over different compliation units and headers, all dealing with SR-IOV specific behavior. This violates the style guide which discourages conditionally compiled code blocks and hinders maintainability by speading SR-IOV functionality over many files. Let's move all of this into a conditionally compiled pci_iov.c file and local header and prefix SR-IOV specific functions with zpci_iov_*. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-08-17s390/pci: fix PF/VF linking on hot plugNiklas Schnelle
Currently there are four places in which a PCI function is scanned and made available to drivers: 1. In pci_scan_root_bus() as part of the initial zbus creation. 2. In zpci_bus_add_devices() when registering a device in configured state on a zbus that has already been scanned. 3. When a function is already known to zPCI (in reserved/standby state) and configuration is triggered through firmware by PEC 0x301. 4. When a device is already known to zPCI (in standby/reserved state) and configuration is triggered from within Linux using enable_slot(). The PF/VF linking step and setting of pdev->is_virtfn introduced with commit e5794cf1a270 ("s390/pci: create links between PFs and VFs") was only triggered for the second case, which is where VFs created through sriov_numvfs usually land. However unlike some other platforms but like POWER VFs can be individually enabled/disabled through /sys/bus/pci/slots. Fix this by doing VF setup as part of pcibios_bus_add_device() which is called in all of the above cases. Finally to remove the PF/VF links call the common code pci_iov_remove_virtfn() function to remove linked VFs. This takes care of the necessary sysfs cleanup. Fixes: e5794cf1a270 ("s390/pci: create links between PFs and VFs") Cc: <stable@vger.kernel.org> # 5.8: 2f0230b2f2d5: s390/pci: re-introduce zpci_remove_device() Cc: <stable@vger.kernel.org> # 5.8 Acked-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-08-17s390/pci: fix zpci_bus_link_virtfn()Niklas Schnelle
We were missing the pci_dev_put() for candidate PFs. Furhtermore in discussion with upstream it turns out that somewhat counterintuitively some common code, in particular the vfio-pci driver, assumes that pdev->is_virtfn always implies that pdev->physfn is set, i.e. that VFs are always linked. While POWER does seem to set pdev->is_virtfn even for unlinked functions (see comments in arch/powerpc/kernel/eeh.c:eeh_debugfs_break_device()) for now just be safe and only set pdev->is_virtfn on linking. Also make sure that we only search for parent PFs if the zbus is multifunction and we thus know the devfn values supplied by firmware come from the RID. Fixes: e5794cf1a270 ("s390/pci: create links between PFs and VFs") Cc: <stable@vger.kernel.org> # 5.8 Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-05-20s390/pci: create links between PFs and VFsNiklas Schnelle
On s390 PCI Virtual Functions (VFs) are scanned by firmware and are made available to Linux via the hot-plug interface. As such the common code path of doing the scan directly using the parent Physical Function (PF) is not used and fenced off with the no_vf_scan attribute. Even if the partition created the VFs itself e.g. using the sriov_numvfs attribute of a PF, the PF/VF links thus need to be established after the fact. To do this when a VF is plugged we scan through all functions on the same zbus and test whether they are the parent PF in which case we establish the necessary links. With these links established there is now no more need to fence off pci_iov_remove_virtfn() for pdev->no_vf_scan as the common code now works fine. Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Link: https://lore.kernel.org/r/20200506154139.90609-3-schnelle@linux.ibm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-05-06s390/pci: removes wrong PCI multifunction assignmentPierre Morel
The assignment of the PCI device multifunction attribute is set during the PCI device probe. There is no need to set it here. Let's do it right and remove this assignment. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28s390/pci: Handling multifunctionsPierre Morel
We allow multiple functions on a single bus. We suppress the ZPCI_DEVFN definition and replace its occurences with zpci->devfn. We verify the number of device during the registration. There can never be more domains in use than existing devices, so we do not need to verify the count of domain after having verified the count of devices. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28s390/pci: Adding bus resourcePierre Morel
The current PCI implementation do not provide a bus resource. This leads to a notice being print at boot. Let's do it more nicely and provide the bus resource. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28s390/pci: create zPCI busPierre Morel
The zPCI bus is in charge to handle common zPCI resources for zPCI devices. Creating the zPCI bus, the PCI bus, the zPCI devices and the PCI devices and hotplug slots done in a specific order: - PCI hotplug slot creation needs a PCI bus - PCI bus needs a PCI domain which is reported by the pci_domain_nr() when setting up the host bridge - PCI domain is set from the zPCI with devfn 0 this is necessary to have a reproducible enumeration Therefore we can not create devices or hotplug slots for any PCI device associated with a zPCI device before having discovered the function zero of the bus. The discovery and initialization of devices can be done at several points in the code: - On Events, serialized in a thread context - On initialization, in the kernel init thread context - When powering on the hotplug slot, in a user thread context The removal of devices and their parent bus may also be done on events or for devices when powering down the slot. To guarantee the existence of the bus and devices until they are no more needed we use kref in zPCI bus and introduce a reference count in the zPCI devices. In this patch the zPCI bus still only accept a device with a devfn 0. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>