kernel/git/next/linux-next.git/drivers/pci, branch master

Merge branch 'next' of https://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux.git

2026-09-11T14:59:50+00:00

Merge branch 'next' of https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git

2026-09-11T12:19:59+00:00

PCI: liveupdate: Do not disable bus mastering on preserved devices during kexec

2026-09-10T18:50:41+00:00

Do not disable bus mastering on outgoing preserved devices during pci_device_shutdown() for kexec. Preserved devices must be allowed to perform memory transactions during a Live Update to ensure continuous operation. Clearing the bus mastering bit would prevent these devices from issuing any memory requests while the new kernel boots. Because bridges upstream of preserved endpoint devices are also automatically preserved, this change also avoids clearing bus mastering on them. This is critical because clearing bus mastering on an upstream bridge prevents the bridge from forwarding memory requests upstream (i.e. it would prevent the endpoint device from accessing system RAM and doing peer-to-peer transactions with devices not downstream of the bridge). Reviewed-by: Pranjal Shrivastava Reviewed-by: Pasha Tatashin Signed-off-by: David Matlack Reviewed-by: Samiullah Khawaja Link: https://patch.msgid.link/20260728221007.2098560-12-dmatlack@google.com Signed-off-by: Pasha Tatashin

PCI: liveupdate: Freeze preservation status during shutdown

2026-09-10T18:50:41+00:00

Freeze a device's outgoing preservation status (preserved or not preserved) during shutdown. This enables the PCI core and drivers to safely make decisions based on the device's preservation status during shutdown. Note that pci_liveupdate_freeze() is triggered by the PCI core rather than from drivers participating in Live Update so that all devices can have their status frozen (i.e. prevent non-preserved devices from getting preserved late). Reviewed-by: Pranjal Shrivastava Reviewed-by: Pasha Tatashin Signed-off-by: David Matlack Reviewed-by: Samiullah Khawaja Link: https://patch.msgid.link/20260728221007.2098560-11-dmatlack@google.com Signed-off-by: Pasha Tatashin

PCI: liveupdate: Adopt ARI Forwarding Enable on preserved bridges

2026-09-10T18:50:41+00:00

Adopt the ARI Forwarding Enable bit on preserved bridges and update pci_dev->ari_enabled accordingly during a Live Update. This ensures that the preserved devices on the bridge's secondary bus can be identified with the same expanded 8-bit function number after a Live Update. Signed-off-by: David Matlack Reviewed-by: Pranjal Shrivastava Link: https://patch.msgid.link/20260728221007.2098560-10-dmatlack@google.com Signed-off-by: Pasha Tatashin

PCI: liveupdate: Adopt ACS controls in incoming preserved devices

2026-09-10T18:50:40+00:00

Adopt Access Control Services (ACS) controls on all incoming preserved devices (endpoints and upstream bridges) during a Live Update. Inheriting ACS flags avoids changing routing rules while memory transactions are in flight from preserved devices. This is also strictly necessary to ensure that IOMMU group assignments do not change during or after Live Update. Cache the inherited ACS controls established by the previous kernel in struct pci_dev so that ACS controls do not change after a reset (pci_restore_state() calls pci_enable_acs()). To simplify ACS inheritance, reject preserving any devices that require quirks to enable ACS as those quirks would also have to take Live Update into account. Reviewed-by: Pasha Tatashin Signed-off-by: David Matlack Reviewed-by: Pranjal Shrivastava Link: https://patch.msgid.link/20260728221007.2098560-9-dmatlack@google.com Signed-off-by: Pasha Tatashin

PCI: Refactor matching logic for pci_dev_acs_ops

2026-09-10T18:50:40+00:00

Refactor the logic to match devices to pci_dev_acs_ops by factoring out the device matching loop into its own routine, pci_dev_acs_ops_get(). This eliminates duplicate code between pci_dev_specific_enable_acs() and pci_dev_specific_disable_acs_redir(), and will also be used in a subsequent commit to check if a device requires device-specific enable_acs() during a Live Update. No functional change intended. Reviewed-by: Pranjal Shrivastava Reviewed-by: Pasha Tatashin Reviewed-by: Bjorn Helgaas Signed-off-by: David Matlack Link: https://patch.msgid.link/20260728221007.2098560-8-dmatlack@google.com Signed-off-by: Pasha Tatashin

PCI: liveupdate: Auto-preserve upstream bridges across Live Update

2026-09-10T18:50:40+00:00

When a PCI device is preserved across a Live Update, all of its upstream bridges up to the root port must also be preserved. This enables the PCI core and any drivers bound to the bridges to manage bridges correctly across a Live Update. Notably, this will be used in subsequent commits to ensure that preserved devices can continue performing memory transactions without a disruption or change in routing. To preserve bridges, the PCI core tracks the number of downstream devices preserved under each bridge using a reference count in struct pci_dev_ser. This allows a bridge to remain preserved until all its downstream preserved devices are unpreserved or finish their participation in the Live Update. Reviewed-by: Pasha Tatashin Signed-off-by: David Matlack Reviewed-by: Pranjal Shrivastava Link: https://patch.msgid.link/20260728221007.2098560-7-dmatlack@google.com Signed-off-by: Pasha Tatashin

PCI: liveupdate: Preserve bus numbers during Live Update

2026-09-10T18:50:39+00:00

During a Live Update, preserved devices must be allowed to continue performing memory transactions so the kernel cannot change the fabric topology, including bus numbers, since that would require disabling and flushing any memory transactions first. To keep bus numbers constant, always preserve the secondary and subordinate bus numbers assigned to bridges during scanning, instead of assigning new ones, if any PCI devices were preserved. Note that the kernel preserves bus numbers even on bridges without any downstream endpoints that were preserved. This avoids accidentally assigning a bridge a new window that overlaps with a preserved device that is downstream of a different bridge. If a bridge is scanned with a broken topology or has no bus numbers set during a Live Update, refuse to assign it new bus numbers and refuse to enumerate devices below it until the Live Update is finished. This is a safety measure to prevent topology conflicts. Require that CONFIG_CARDBUS is not enabled to enable CONFIG_PCI_LIVEUPDATE since preserving bus numbers on PCI-to-CardBus bridges requires additional work but is not a priority at the moment. Reviewed-by: Pranjal Shrivastava Reviewed-by: Samiullah Khawaja Reviewed-by: Pasha Tatashin Signed-off-by: David Matlack Link: https://patch.msgid.link/20260728221007.2098560-6-dmatlack@google.com Signed-off-by: Pasha Tatashin

PCI: liveupdate: Document driver binding responsibilities

2026-09-10T18:50:39+00:00

Document how driver binding works during a Live Update and what the PCI core expects of drivers and users. Note that this is only a description of the current division of responsibilities. These can change in the future if we decide. Reviewed-by: Pasha Tatashin Reviewed-by: Pranjal Shrivastava Reviewed-by: Samiullah Khawaja Signed-off-by: David Matlack Link: https://patch.msgid.link/20260728221007.2098560-5-dmatlack@google.com Signed-off-by: Pasha Tatashin