kernel.git/drivers/pci/probe.c, branch linux-6.10.y

PCI: Revert the cfg_access_lock lockdep mechanism

2024-06-04T17:10:05Z

While the experiment did reveal that there are additional places that are missing the lock during secondary bus reset, one of the places that needs to take cfg_access_lock (pci_bus_lock()) is not prepared for lockdep annotation. Specifically, pci_bus_lock() takes pci_dev_lock() recursively and is currently dependent on the fact that the device_lock() is marked lockdep_set_novalidate_class(&dev->mutex). Otherwise, without that annotation, pci_bus_lock() would need to use something like a new pci_dev_lock_nested() helper, a scheme to track a PCI device's depth in the topology, and a hope that the depth of a PCI tree never exceeds the max value for a lockdep subclass. The alternative to ripping out the lockdep coverage would be to deploy a dynamic lock key for every PCI device. Unfortunately, there is evidence that increasing the number of keys that lockdep needs to track to be per-PCI-device is prohibitively expensive for something like the cfg_access_lock. The main motivation for adding the annotation in the first place was to catch unlocked secondary bus resets, not necessarily catch lock ordering problems between cfg_access_lock and other locks. Solve that narrower problem with follow-on patches, and just due to targeted revert for now. Link: https://lore.kernel.org/r/171711746402.1628941.14575335981264103013.stgit@dwillia2-xfh.jf.intel.com Fixes: 7e89efc6e9e4 ("PCI: Lock upstream bridge for pci_reset_function()") Reported-by: Imre Deak Closes: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_134186v1/shard-dg2-1/igt@device_reset@unbind-reset-rebind.html Signed-off-by: Dan Williams Signed-off-by: Bjorn Helgaas Tested-by: Hans de Goede Tested-by: Kalle Valo Reviewed-by: Dave Jiang Cc: Jani Saarinen

Merge branch 'pci/misc'

2024-05-16T23:14:14Z

- Constify pcibus_class (Heiner Kallweit) - Annotate pci_cache_line_size variables as __ro_after_init (Heiner Kallweit) - Clean up formatting of PCI accessor macros (Ilpo Järvinen) - Remove some OLPC dead code (Kunwu Chan) - Make pcie_bandwidth_capable() static (Ilpo Järvinen) * pci/misc: PCI: Make pcie_bandwidth_capable() static x86/pci: Remove OLPC dead code PCI: Clean up accessor macro formatting PCI/ERR: Cleanup misleading indentation inside if conditions PCI: Annotate pci_cache_line_size variables as __ro_after_init PCI: Constify pcibus_class

Merge branch 'pci/enumeration'

2024-05-16T23:14:10Z

- Clear bridge Secondary Status errors after enumeration since enumeration causes many errors (Vidya Sagar) - Wait for Link Training==0 before starting Link retrain to avoid a race; this was done previously but broken by a faulty merge (Ilpo Järvinen) - Rename PCI_IRQ_LEGACY to PCI_IRQ_INTX to be more specific about what "LEGACY" means (Damien Le Moal) - Update return types of pci_find_capability() stubs to match the extern declarations for the actual implementations (Bjorn Helgaas) - Drop unnecessary pci_enable_device_io() from pata_cs5520 (Heiner Kallweit) - Drop unused pci_enable_device_io() (Heiner Kallweit) - On 2016 and newer BIOSes, skip early E820 check for ECAM regions described in ACPI MCFG; there's no spec requirement for E820 reservations, and some machines don't provide them (Bjorn Helgaas) - If devices were disconnected while suspended, don't wait for them when resuming (Ilpo Järvinen) * pci/enumeration: PCI: Do not wait for disconnected devices when resuming x86/pci: Skip early E820 check for ECAM region PCI: Remove unused pci_enable_device_io() ata: pata_cs5520: Remove unnecessary call to pci_enable_device_io() PCI: Update pci_find_capability() stub return types PCI: Remove PCI_IRQ_LEGACY scsi: vmw_pvscsi: Do not use PCI_IRQ_LEGACY instead of PCI_IRQ_LEGACY scsi: pmcraid: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY scsi: mpt3sas: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY scsi: megaraid_sas: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY scsi: ipr: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY scsi: hpsa: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY scsi: arcmsr: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY wifi: rtw89: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY wifi: rtw88: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY wifi: ath10k: Refer to INTX instead of LEGACY net: wangxun: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY r8169: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY net: alx: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY net: atlantic: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY net: amd-xgbe: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY VMCI: Use PCI_IRQ_ALL_TYPES to remove PCI_IRQ_LEGACY use RDMA/vmw_pvrdma: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY IB/qib: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY drm/amdgpu: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY mfd: intel-lpss: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY ntb: idt: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY platform/x86: intel_ips: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY tty: 8250_pci: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY usb: hcd-pci: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY ASoC: Intel: avs: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY Documentation: PCI: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY PCI/portdrv: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY PCI/MSI: Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY PCI: Clarify intent of LT wait PCI: Wait for Link Training==0 before starting Link retrain PCI: Clear Secondary Status errors after enumeration

PCI: Lock upstream bridge for pci_reset_function()

2024-05-08T18:19:20Z

Fix a long-standing locking gap for missing pci_cfg_access_lock() while manipulating bridge reset registers and configuration during pci_reset_bus_function(). If there is an upstream bridge, lock it before locking the device itself. pci_dev_lock() calls pci_cfg_access_lock(), which blocks the writing of PCI config space by user space. Add lockdep assertion via pci_dev->cfg_access_lock to verify pci_dev->block_cfg_access is set. Co-developed-by: Dan Williams Link: https://lore.kernel.org/r/20240502165851.1948523-3-dave.jiang@intel.com Signed-off-by: Dan Williams Signed-off-by: Dave Jiang [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas

PCI: Clear Secondary Status errors after enumeration

2024-04-23T21:08:17Z

We enumerate devices by attempting config reads to the Vendor ID of each possible device. On conventional PCI, if no device responds, the read terminates with a Master Abort (PCI r3.0, sec 6.1). On PCIe, the config read is terminated as an Unsupported Request (PCIe r6.0, sec 2.3.2, 7.5.1.3.7). In either case, if the read addressed a device below a bridge, it is logged by setting "Received Master Abort" in the bridge Secondary Status register. Clear any errors logged in the Secondary Status register after enumeration. Link: https://lore.kernel.org/r/20240116143258.483235-1-vidyas@nvidia.com Signed-off-by: Vidya Sagar [bhelgaas: simplify commit log] Signed-off-by: Bjorn Helgaas

PCI: Constify pcibus_class

2024-04-17T15:44:17Z

Constify pcibus_class. All users take a const struct class * argument. Link: https://lore.kernel.org/r/5e01f46f-266f-4fb3-be8a-8cb9e566cd75@gmail.com Signed-off-by: Heiner Kallweit Signed-off-by: Bjorn Helgaas

Merge branch 'pci/sysfs'

2024-03-12T17:14:23Z

- Compile pci-sysfs.c only if CONFIG_SYSFS=y, which reduces kernel size by ~120KB when it's disabled (Lukas Wunner) - Remove obsolete pci_cleanup_rom() declaration (Lukas Wunner) - Rework pci_dev_resource_resize_attr(n) macros to call a function instead of duplicating most of the body, which saves about 2.5KB of text (Ilpo Järvinen) * pci/sysfs: PCI/sysfs: Demacrofy pci_dev_resource_resize_attr(n) functions PCI: Remove obsolete pci_cleanup_rom() declaration PCI/sysfs: Compile pci-sysfs.c only if CONFIG_SYSFS=y # Conflicts: # drivers/pci/Makefile

PCI/ASPM: Save L1 PM Substates Capability for suspend/resume

2024-03-12T16:53:45Z

4ff116d0d5fd ("PCI/ASPM: Save L1 PM Substates Capability for suspend/resume") restored the L1 PM Substates Capability after resume, which reduced power consumption by making the ASPM L1.x states work after resume. a7152be79b62 ("Revert "PCI/ASPM: Save L1 PM Substates Capability for suspend/resume"") reverted 4ff116d0d5fd because resume failed on some systems, so power consumption after resume increased again. a7152be79b62 mentioned that we restore L1 PM substate configuration even though ASPM L1 may already be enabled. This is due the fact that the pci_restore_aspm_l1ss_state() was called before pci_restore_pcie_state(). Save and restore the L1 PM Substates Capability, following PCIe r6.1, sec 5.5.4 more closely by: 1) Do not restore ASPM configuration in pci_restore_pcie_state() but do that after PCIe capability is restored in pci_restore_aspm_state() following PCIe r6.1, sec 5.5.4. 2) If BIOS reenables L1SS, particularly L1.2, we need to clear the enables in the right order, downstream before upstream. Defer restoring the L1SS config until we are at the downstream component. Then update the config for both ends of the link in the prescribed order. 3) Program ASPM L1 PM substate configuration before L1 enables. 4) Program ASPM L1 PM substate enables last, after rest of the fields in the capability are programmed. [bhelgaas: commit log, squash L1SS-related patches, do both LNKCTL restores in pci_restore_pcie_state()] Link: https://lore.kernel.org/r/20240128233212.1139663-3-david.e.box@linux.intel.com Link: https://lore.kernel.org/r/20240128233212.1139663-4-david.e.box@linux.intel.com Link: https://lore.kernel.org/r/20240223205851.114931-5-helgaas@kernel.org Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217321 Link: https://bugzilla.kernel.org/show_bug.cgi?id=216782 Link: https://bugzilla.kernel.org/show_bug.cgi?id=216877 Co-developed-by: Mika Westerberg Co-developed-by: David E. Box Reported-by: Koba Ko Signed-off-by: Mika Westerberg Signed-off-by: David E. Box Signed-off-by: Bjorn Helgaas Tested-by: Tasev Nikola # Asus UX305FA Cc: Mark Enriquez Cc: Thomas Witt Cc: Werner Sembach Cc: Vidya Sagar

PCI/ASPM: Move pci_configure_ltr() to aspm.c

2024-03-07T20:29:08Z

The Latency Tolerance Reporting (LTR) mechanism supports the ASPM L1.2 state and is only configured when CONFIG_PCIEASPM is set. Move pci_configure_ltr() and pci_bridge_reconfigure_ltr() into aspm.c since they only build when CONFIG_PCIEASPM is set. No functional change intended. Suggested-by: Bjorn Helgaas Link: https://lore.kernel.org/r/20240128233212.1139663-2-david.e.box@linux.intel.com [bhelgaas: commit log, split build change from function moves] Link: https://lore.kernel.org/r/20240223205851.114931-2-helgaas@kernel.org Signed-off-by: David E. Box Signed-off-by: Bjorn Helgaas

PCI/sysfs: Compile pci-sysfs.c only if CONFIG_SYSFS=y

2024-03-05T22:08:43Z

It is possible to enable CONFIG_PCI but disable CONFIG_SYSFS and for space-constrained devices such as routers, such a configuration may actually make sense. However pci-sysfs.c is compiled even if CONFIG_SYSFS is disabled, unnecessarily increasing the kernel's size. To rectify that: * Move pci_mmap_fits() to mmap.c. It is not only needed by pci-sysfs.c, but also proc.c. * Move pci_dev_type to probe.c and make it private. It references pci_dev_attr_groups in pci-sysfs.c. Make that public instead for consistency with pci_dev_groups, pcibus_groups and pci_bus_groups, which are likewise public and referenced by struct definitions in pci-driver.c and probe.c. * Define pci_dev_groups, pci_dev_attr_groups, pcibus_groups and pci_bus_groups to NULL if CONFIG_SYSFS is disabled. Provide empty static inlines for pci_{create,remove}_legacy_files() and pci_{create,remove}_sysfs_dev_files(). Result: vmlinux size is reduced by 122996 bytes in my arm 32-bit test build. Link: https://lore.kernel.org/r/85ca95ae8e4d57ccf082c5c069b8b21eb141846e.1698668982.git.lukas@wunner.de Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Reviewed-by: Alistair Francis