kernel/linux.git/drivers/pci/probe.c, branch v6.6.131

PCI: Use resource_set_range() that correctly sets ->end

2026-03-25T10:05:31+00:00

[ Upstream commit 11721c45a8266a9d0c9684153d20e37159465f96 ] __pci_read_base() sets resource start and end addresses when resource is larger than 4G but pci_bus_addr_t or resource_size_t are not capable of representing 64-bit PCI addresses. This creates a problematic resource that has non-zero flags but the start and end addresses do not yield to resource size of 0 but 1. Replace custom resource addresses setup with resource_set_range() that correctly sets end address as -1 which results in resource_size() returning 0. For consistency, also use resource_set_range() in the other branch that does size based resource setup. Fixes: 23b13bc76f35 ("PCI: Fail safely if we can't handle BARs larger than 4GB") Link: https://lore.kernel.org/all/20251207215359.28895-1-ansuelsmth@gmail.com/T/#m990492684913c5a158ff0e5fc90697d8ad95351b Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Reviewed-by: Andy Shevchenko Cc: stable@vger.kernel.org Cc: Christian Marangi Link: https://patch.msgid.link/20251208145654.5294-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Sasha Levin

PCI: Use resource names in PCI log messages

2026-03-25T10:05:31+00:00

[ Upstream commit dc4e6f21c3f844ebc1c52b6920b8ec5dfc73f4e8 ] Use the pci_resource_name() to get the name of the resource and use it while printing log messages. [bhelgaas: rename to match struct resource * names, also use names in other BAR messages] Link: https://lore.kernel.org/r/20211106112606.192563-3-puranjay12@gmail.com Signed-off-by: Puranjay Mohan Signed-off-by: Bjorn Helgaas Stable-dep-of: 11721c45a826 ("PCI: Use resource_set_range() that correctly sets ->end") Signed-off-by: Sasha Levin

PCI: Add defines for bridge window indexing

2026-03-04T12:19:48+00:00

[ Upstream commit e4934832c588f72bcc139d3ca0acc490c63a821c ] include/linux/pci.h provides PCI_BRIDGE_{IO,MEM,PREF_MEM}_WINDOW defines, however, they're based on the resource array indexing in the pci_dev struct. The struct pci_bus also has pointers to those same resources but they start from zeroth index. Add PCI_BUS_BRIDGE_{IO,MEM,PREF_MEM}_WINDOW defines to get rid of literal indexing. Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20250829131113.36754-12-ilpo.jarvinen@linux.intel.com Stable-dep-of: 9abf79c8d7b4 ("PCI/ACPI: Restrict program_hpx_type2() to AER bits") Signed-off-by: Sasha Levin

PCI: Log bridge info when first enumerating bridge

2026-03-04T12:19:48+00:00

[ Upstream commit 95140c2fbfdf3b6ca98578e5bdbc82d9922f08b9 ] Log bridge secondary/subordinate bus and window information at the same time we log the bridge BARs, just after discovering the bridge and before scanning the bridge's secondary bus. This logs the bridge and downstream devices in a more logical order: - pci 0000:00:01.0: [8086:1901] type 01 class 0x060400 - pci 0000:01:00.0: [10de:13b6] type 00 class 0x030200 - pci 0000:01:00.0: reg 0x10: [mem 0xec000000-0xecffffff] - pci 0000:00:01.0: PCI bridge to [bus 01] - pci 0000:00:01.0: bridge window [io 0xe000-0xefff] + pci 0000:00:01.0: [8086:1901] type 01 class 0x060400 + pci 0000:00:01.0: PCI bridge to [bus 01] + pci 0000:00:01.0: bridge window [io 0xe000-0xefff] + pci 0000:01:00.0: [10de:13b6] type 00 class 0x030200 + pci 0000:01:00.0: reg 0x10: [mem 0xec000000-0xecffffff] Note that we read the windows into a temporary struct resource that is thrown away, not into the resources in the struct pci_bus. The windows may be adjusted after we know what downstream devices require, and those adjustments are logged as they are made. Signed-off-by: Bjorn Helgaas Stable-dep-of: 9abf79c8d7b4 ("PCI/ACPI: Restrict program_hpx_type2() to AER bits") Signed-off-by: Sasha Levin

PCI: Log bridge windows conditionally

2026-03-04T12:19:48+00:00

[ Upstream commit 63c6ebb294b7c708cc987d621e59499686650683 ] Previously pci_read_bridge_io(), pci_read_bridge_mmio(), and pci_read_bridge_mmio_pref() unconditionally logged the bridge window resource. A future change will call these functions earlier and more often. Add a "log" parameter so callers can control whether to generate the log message. No functional change intended. Signed-off-by: Bjorn Helgaas Stable-dep-of: 9abf79c8d7b4 ("PCI/ACPI: Restrict program_hpx_type2() to AER bits") Signed-off-by: Sasha Levin

PCI: Supply bridge device, not secondary bus, to read window details

2026-03-04T12:19:47+00:00

[ Upstream commit 281e1f137a97dae4fe47a7d30635c5b83def790b ] Previously we logged information about devices *below* the bridge before logging information about the bridge itself, e.g., pci 0000:00:01.0: [8086:1901] type 01 class 0x060400 pci 0000:01:00.0: [10de:13b6] type 00 class 0x030200 pci 0000:01:00.0: reg 0x10: [mem 0xec000000-0xecffffff] pci 0000:00:01.0: PCI bridge to [bus 01] pci 0000:00:01.0: bridge window [io 0xe000-0xefff] This is partly because the bridge windows are read in this path: pci_scan_child_bus_extend for (devfn = 0; devfn < 256; devfn += 8) pci_scan_slot(bus, devfn) # scan below bridge pcibios_fixup_bus(bus) pci_read_bridge_bases(bus) # read bridge windows pci_read_bridge_io(bus) Remove the assumption that the secondary (child) pci_bus already exists by passing in the bridge device (instead of the pci_bus) and a resource pointer when reading bridge windows. A future change can use this to log the bridge details before we enumerate the devices below the bridge. No functional change intended. Signed-off-by: Bjorn Helgaas Stable-dep-of: 9abf79c8d7b4 ("PCI/ACPI: Restrict program_hpx_type2() to AER bits") Signed-off-by: Sasha Levin

PCI: Move pci_read_bridge_windows() below individual window accessors

2026-03-04T12:19:47+00:00

[ Upstream commit 6f32099a91720b6d91da961858d48173f01a729d ] Move pci_read_bridge_windows() below the functions that read the I/O, memory, and prefetchable memory windows, so pci_read_bridge_windows() can use them in the future. No functional change intended. Signed-off-by: Bjorn Helgaas Stable-dep-of: 9abf79c8d7b4 ("PCI/ACPI: Restrict program_hpx_type2() to AER bits") Signed-off-by: Sasha Levin

PCI: Initialize RCB from pci_configure_device()

2026-03-04T12:19:47+00:00

[ Upstream commit 1a6845aaa6de81f95959b380b45de8f10d6a8502 ] Commit e42010d8207f ("PCI: Set Read Completion Boundary to 128 iff Root Port supports it (_HPX)") worked around a bogus _HPX type 2 record, which caused program_hpx_type2() to set the RCB in an endpoint even though the Root Port did not have the RCB bit set. e42010d8207f fixed that by setting the RCB in the endpoint only when it was set in the Root Port. In retrospect, program_hpx_type2() is intended for AER-related settings, and the RCB should be configured elsewhere so it doesn't depend on the presence or contents of an _HPX record. Explicitly program the RCB from pci_configure_device() so it matches the Root Port's RCB. The Root Port may not be visible to virtualized guests; in that case, leave RCB alone. Fixes: e42010d8207f ("PCI: Set Read Completion Boundary to 128 iff Root Port supports it (_HPX)") Signed-off-by: Håkon Bugge Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20260129175237.727059-2-haakon.bugge@oracle.com Signed-off-by: Sasha Levin

PCI: Do not attempt to set ExtTag for VFs

2026-03-04T12:19:43+00:00

[ Upstream commit 73711730a1128d91ebca1a6994ceeb18f36cb0cd ] The bit for enabling extended tags is Reserved and Preserved (RsvdP) for VFs, according to PCIe r7.0 section 7.5.3.4 table 7.21. Hence, bail out early from pci_configure_extended_tags() if the device is a VF. Otherwise, we may see incorrect log messages such as: kernel: pci 0000:af:00.2: enabling Extended Tags (af:00.2 is a VF) Fixes: 60db3a4d8cc9 ("PCI: Enable PCIe Extended Tags if supported") Signed-off-by: Håkon Bugge Signed-off-by: Bjorn Helgaas Reviewed-by: Zhu Yanjun Link: https://patch.msgid.link/20251112095442.1913258-1-haakon.bugge@oracle.com Signed-off-by: Sasha Levin

PCI/ACPI: Fix runtime PM ref imbalance on Hot-Plug Capable ports

2025-08-28T14:28:40+00:00

[ Upstream commit 6cff20ce3b92ffbf2fc5eb9e5a030b3672aa414a ] pci_bridge_d3_possible() is called from both pcie_portdrv_probe() and pcie_portdrv_remove() to determine whether runtime power management shall be enabled (on probe) or disabled (on remove) on a PCIe port. The underlying assumption is that pci_bridge_d3_possible() always returns the same value, else a runtime PM reference imbalance would occur. That assumption is not given if the PCIe port is inaccessible on remove due to hot-unplug: pci_bridge_d3_possible() calls pciehp_is_native(), which accesses Config Space to determine whether the port is Hot-Plug Capable. An inaccessible port returns "all ones", which is converted to "all zeroes" by pcie_capability_read_dword(). Hence the port no longer seems Hot-Plug Capable on remove even though it was on probe. The resulting runtime PM ref imbalance causes warning messages such as: pcieport 0000:02:04.0: Runtime PM usage count underflow! Avoid the Config Space access (and thus the runtime PM ref imbalance) by caching the Hot-Plug Capable bit in struct pci_dev. The struct already contains an "is_hotplug_bridge" flag, which however is not only set on Hot-Plug Capable PCIe ports, but also Conventional PCI Hot-Plug bridges and ACPI slots. The flag identifies bridges which are allocated additional MMIO and bus number resources to allow for hierarchy expansion. The kernel is somewhat sloppily using "is_hotplug_bridge" in a number of places to identify Hot-Plug Capable PCIe ports, even though the flag encompasses other devices. Subsequent commits replace these occurrences with the new flag to clearly delineate Hot-Plug Capable PCIe ports from other kinds of hotplug bridges. Document the existing "is_hotplug_bridge" and the new "is_pciehp" flag and document the (non-obvious) requirement that pci_bridge_d3_possible() always returns the same value across the entire lifetime of a bridge, including its hot-removal. Fixes: 5352a44a561d ("PCI: pciehp: Make pciehp_is_native() stricter") Reported-by: Laurent Bigonville Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220216 Reported-by: Mario Limonciello Closes: https://lore.kernel.org/r/20250609020223.269407-3-superm1@kernel.org/ Link: https://lore.kernel.org/all/20250620025535.3425049-3-superm1@kernel.org/T/#u Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki Cc: stable@vger.kernel.org # v4.18+ Link: https://patch.msgid.link/fe5dcc3b2e62ee1df7905d746bde161eb1b3291c.1752390101.git.lukas@wunner.de [ changed "recent enough PCIe ports" comment to "some PCIe ports" ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman