kernel/linux.git/drivers/pci/search.c, branch linux-7.1.y

PCI: Add PCI_BRIDGE_NO_ALIAS quirk for ASPEED AST1150

2026-01-13T17:46:33+00:00

ASPEED BMC controllers have VGA and USB functions behind a PCIe-to-PCI bridge that causes them to share the same StreamID: [e0]---00.0-[e1-e2]----00.0-[e2]--+-00.0 ASPEED Graphics Family \-02.0 ASPEED USB Controller Both devices get StreamID 0x5e200 due to bridge aliasing, causing the USB controller to be rejected with 'Aliasing StreamID unsupported'. Per ASPEED, the AST1150 doesn't use a real PCI bus and always forwards the original Requester ID from downstream devices rather than replacing it with any alias. Add a new PCI_DEV_FLAGS_PCI_BRIDGE_NO_ALIAS flag and apply it to the AST1150. Suggested-by: Jason Gunthorpe Signed-off-by: Nirmoy Das Signed-off-by: Bjorn Helgaas Reviewed-by: Robin Murphy Reviewed-by: Jason Gunthorpe Link: https://patch.msgid.link/20251217154529.377586-2-nirmoyd@nvidia.com

PCI: Introduce pci_walk_bus_reverse(), for_each_pci_dev_reverse()

2025-11-04T03:27:40+00:00

PCI/TSM, the PCI core functionality for the PCIe TEE Device Interface Security Protocol (TDISP), has a need to walk all subordinate functions of a Device Security Manager (DSM) to setup a device security context. A DSM is physical function 0 of multi-function or SR-IOV device endpoint, or it is an upstream switch port. In error scenarios or when a TEE Security Manager (TSM) device is removed it needs to unwind all established DSM contexts. Introduce reverse versions of PCI device iteration helpers to mirror the setup path and ensure that dependent children are handled before parents. Cc: Greg Kroah-Hartman Reviewed-by: Jonathan Cameron Link: https://patch.msgid.link/20251031212902.2256310-4-dan.j.williams@intel.com Signed-off-by: Dan Williams

PCI: Add pci_get_base_class() helper

2023-09-28T21:49:44+00:00

There is no function to get all PCI devices in a system by matching against the base class code only, ignoring the sub-class code and the programming interface. Add pci_get_base_class() to suit the need. For example, if a driver wants to process all PCI display devices in a system, it can do so like this: pdev = NULL; while ((pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev))) { do_something_for_pci_display_device(pdev); } Link: https://lore.kernel.org/r/20230825062714.6325-2-sui.jingfeng@linux.dev Signed-off-by: Sui Jingfeng [bhelgaas: reword commit log] Signed-off-by: Bjorn Helgaas Reviewed-by: Alex Deucher

PCI: Remove WARN_ON(in_interrupt())

2021-02-10T22:46:29+00:00

WARN_ON(in_interrupt()) is used for historic reasons to ensure proper usage of down_read() and predates might_sleep() and lockdep. down_read() has might_sleep() which also catches users from preemption disabled regions while in_interrupt() does not. Remove WARN_ON(in_interrupt()) because there are now better debugging facilities. Link: https://lore.kernel.org/r/20210208194400.384003-1-bigeasy@linutronix.de Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Bjorn Helgaas

Merge branch 'pci/host-vmd'

2020-01-29T23:00:02+00:00

- Save VMD's pci_dev in x86 struct pci_sysdata (Jon Derrick) - Add pci_real_dma_dev() for DMA aliases not on the same bus as requester (Jon Derrick) - Add IOMMU mappings for pci_real_dma_dev() (Jon Derrick) - Remove IOMMU sanity checks for VMD devices (Jon Derrick) - Remove VMD dma_map_ops overrides (Jon Derrick) - Remove unused X86_DEV_DMA_OPS (Christoph Hellwig) - Add VMD device IDs that need bus restriction mode (Sushma Kalakota) * pci/host-vmd: PCI: vmd: Add two VMD Device IDs x86/PCI: Remove X86_DEV_DMA_OPS PCI: vmd: Remove dma_map_ops overrides iommu/vt-d: Remove VMD child device sanity check iommu/vt-d: Use pci_real_dma_dev() for mapping PCI: Introduce pci_real_dma_dev() x86/PCI: Expose VMD's pci_dev in struct pci_sysdata x86/PCI: Add to_pci_sysdata() helper

PCI: Introduce pci_real_dma_dev()

2020-01-24T20:55:26+00:00

The current DMA alias implementation requires the aliased device be on the same PCI bus as the requester ID. Add an arch-specific mechanism to point to another PCI device when doing mapping and PCI DMA alias search. The default case returns the actual device. Link: https://lore.kernel.org/r/1579613871-301529-4-git-send-email-jonathan.derrick@intel.com Signed-off-by: Jon Derrick Signed-off-by: Bjorn Helgaas Cc: Christoph Hellwig

PCI: Fix pci_add_dma_alias() bitmask size

2019-12-18T18:21:16+00:00

The number of possible devfns is 256, but pci_add_dma_alias() allocated a bitmap of size 255. Fix this off-by-one error. This fixes commits 338c3149a221 ("PCI: Add support for multiple DMA aliases") and c6635792737b ("PCI: Allocate dma_alias_mask with bitmap_zalloc()"), but I doubt it was possible to see a problem because it takes 4 64-bit longs (or 8 32-bit longs) to hold 255 bits, and bitmap_zalloc() doesn't save the 255-bit size anywhere. [bhelgaas: commit log, move #define to drivers/pci/pci.h, include loop limit fix from Qian Cai: https://lore.kernel.org/r/20191218170004.5297-1-cai@lca.pw] Signed-off-by: James Sewart Signed-off-by: Bjorn Helgaas Reviewed-by: Logan Gunthorpe

PCI: Unexport pci_bus_sem

2019-07-23T23:32:50+00:00

pci_bus_sem is not used by a loadable kernel module and does not need to be exported. It was exported by ce29ca3ea407 ("PCI: acpiphp: remove all functions in slot, even without ACPI _EJx"), which added a use of pci_bus_sem in acpiphp, which could be built as a module at that time. But since 6037a803b05e ("PCI: acpiphp: Convert acpiphp to be builtin only, not modular"), it can no longer be built as a module. Link: https://lore.kernel.org/r/20190718032951.40188-1-skunberg.kelsey@gmail.com Signed-off-by: Kelsey Skunberg Signed-off-by: Bjorn Helgaas

bus_find_device: Unify the match callback with class_find_device

2019-06-24T03:22:31+00:00

There is an arbitrary difference between the prototypes of bus_find_device() and class_find_device() preventing their callers from passing the same pair of data and match() arguments to both of them, which is the const qualifier used in the prototype of class_find_device(). If that qualifier is also used in the bus_find_device() prototype, it will be possible to pass the same match() callback function to both bus_find_device() and class_find_device(), which will allow some optimizations to be made in order to avoid code duplication going forward. Also with that, constify the "data" parameter as it is passed as a const to the match function. For this reason, change the prototype of bus_find_device() to match the prototype of class_find_device() and adjust its callers to use the const qualifier in accordance with the new prototype of it. Cc: Alexander Shishkin Cc: Andrew Lunn Cc: Andreas Noever Cc: Arnd Bergmann Cc: Bjorn Helgaas Cc: Corey Minyard Cc: Christian Borntraeger Cc: David Kershner Cc: "David S. Miller" Cc: David Airlie Cc: Felipe Balbi Cc: Frank Rowand Cc: Grygorii Strashko Cc: Harald Freudenberger Cc: Hartmut Knaack Cc: Heiko Stuebner Cc: Jason Gunthorpe Cc: Jonathan Cameron Cc: "James E.J. Bottomley" Cc: Len Brown Cc: Mark Brown Cc: Michael Ellerman Cc: Michael Jamet Cc: "Martin K. Petersen" Cc: Peter Oberparleiter Cc: Sebastian Ott Cc: Srinivas Kandagatla Cc: Yehezkel Bernat Cc: rafael@kernel.org Acked-by: Corey Minyard Acked-by: David Kershner Acked-by: Mark Brown Acked-by: Rafael J. Wysocki Acked-by: Srinivas Kandagatla Acked-by: Wolfram Sang # for the I2C parts Acked-by: Rob Herring Signed-off-by: Suzuki K Poulose Signed-off-by: Greg Kroah-Hartman

PCI: Add pci_dev_id() helper

2019-04-29T21:12:05+00:00

In several places in the kernel we find PCI_DEVID used like this: PCI_DEVID(dev->bus->number, dev->devfn) Add a "pci_dev_id(struct pci_dev *dev)" helper to simplify callers. Signed-off-by: Heiner Kallweit Signed-off-by: Bjorn Helgaas