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path: root/drivers/pci/setup-bus.c
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2026-02-11Merge tag 'pci-v7.0-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci Pull PCI updates from Bjorn Helgaas: "Enumeration: - Don't try to enable Extended Tags on VFs since that bit is Reserved and causes misleading log messages (Håkon Bugge) - Initialize Endpoint Read Completion Boundary to match Root Port, regardless of ACPI _HPX (Håkon Bugge) - Apply _HPX PCIe Setting Record only to AER configuration, and only when OS owns PCIe hotplug but not AER, to avoid clobbering Extended Tag and Relaxed Ordering settings (Håkon Bugge) Resource management: - Move CardBus code to setup-cardbus.c and only build it when CONFIG_CARDBUS is set (Ilpo Järvinen) - Fix bridge window alignment with optional resources, where additional alignment requirement was previously lost (Ilpo Järvinen) - Stop over-estimating bridge window size since they are now assigned without any gaps between them (Ilpo Järvinen) - Increase resource MAX_IORES_LEVEL to avoid /proc/iomem flattening for nested bridges and endpoints (Ilpo Järvinen) - Add pbus_mem_size_optional() to handle sizes of optional resources (SR-IOV VF BARs, expansion ROMs, bridge windows) (Ilpo Järvinen) - Don't claim disabled bridge windows to avoid spurious claim failures (Ilpo Järvinen) Driver binding: - Fix device reference leak in pcie_port_remove_service() (Uwe Kleine-König) - Move pcie_port_bus_match() and pcie_port_bus_type to PCIe-specific portdrv.c (Uwe Kleine-König) - Convert portdrv to use pcie_port_bus_type.probe() and .remove() callbacks so .probe() and .remove() can eventually be removed from struct device_driver (Uwe Kleine-König) Error handling: - Clear stale errors on reporting agents upon probe so they don't look like recent errors (Lukas Wunner) - Add generic RAS tracepoint for hotplug events (Shuai Xue) - Add RAS tracepoint for link speed changes (Shuai Xue) Power management: - Avoid redundant delay on transition from D3hot to D3cold if the device was already in D3hot (Brian Norris) - Prevent runtime suspend until devices are fully initialized to avoid saving incompletely configured device state (Brian Norris) Power control: - Add power_on/off callbacks with generic signature to pwrseq, tc9563, and slot drivers so they can be used by pwrctrl core (Manivannan Sadhasivam) - Add PCIe M.2 connector support to the slot pwrctrl driver (Manivannan Sadhasivam) - Switch to pwrctrl interfaces to create, destroy, and power on/off devices, calling them from host controller drivers instead of the PCI core (Manivannan Sadhasivam) - Drop qcom .assert_perst() callbacks since this is now done by the controller driver instead of the pwrctrl driver (Manivannan Sadhasivam) Virtualization: - Remove an incorrect unlock in pci_slot_trylock() error handling (Jinhui Guo) - Lock the bridge device for slot reset (Keith Busch) - Enable ACS after IOMMU configuration on OF platforms so ACS is enabled an all devices; previously the first device enumerated (typically a Root Port) didn't have ACS enabled (Manivannan Sadhasivam) - Disable ACS Source Validation for IDT 0x80b5 and 0x8090 switches to work around hardware erratum; previously ACS SV was only temporarily disabled, which worked for enumeration but not after reset (Manivannan Sadhasivam) Peer-to-peer DMA: - Release per-CPU pgmap ref when vm_insert_page() fails to avoid hang when removing the PCI device (Hou Tao) - Remove incorrect p2pmem_alloc_mmap() warning about page refcount (Hou Tao) Endpoint framework: - Add configfs sub-groups synchronously to avoid NULL pointer dereference when racing with removal (Liu Song) - Fix swapped parameters in pci_{primary/secondary}_epc_epf_unlink() functions (Manikanta Maddireddy) ASPEED PCIe controller driver: - Add ASPEED Root Complex DT binding and driver (Jacky Chou) Freescale i.MX6 PCIe controller driver: - Add DT binding and driver support for an optional external refclock in addition to the refclock from the internal PLL (Richard Zhu) - Fix CLKREQ# control so host asserts it during enumeration and Endpoints can use it afterwards to exit the L1.2 link state (Richard Zhu) NVIDIA Tegra PCIe controller driver: - Export irq_domain_free_irqs() to allow PCI/MSI drivers that tear down MSI domains to be built as modules (Aaron Kling) - Allow pci-tegra to be built as a module (Aaron Kling) NVIDIA Tegra194 PCIe controller driver: - Relax Kconfig so tegra194 can be built for platforms beyond Tegra194 (Vidya Sagar) Qualcomm PCIe controller driver: - Merge SC8180x DT binding into SM8150 (Krzysztof Kozlowski) - Move SDX55, SDM845, QCS404, IPQ5018, IPQ6018, IPQ8074 Gen3, IPQ8074, IPQ4019, IPQ9574, APQ8064, MSM8996, APQ8084 to dedicated schema (Krzysztof Kozlowski) - Add DT binding and driver support for SA8255p Endpoint being configured by firmware (Mrinmay Sarkar) - Parse PERST# from all PCIe bridge nodes for future platforms that will have PERST# in Switch Downstream Ports as well as in Root Ports (Manivannan Sadhasivam) Renesas RZ/G3S PCIe controller driver: - Use pci_generic_config_write() since the writability provided by the custom wrapper is unnecessary (Claudiu Beznea) SOPHGO PCIe controller driver: - Disable ASPM L0s and L1 on Sophgo 2044 PCIe Root Ports (Inochi Amaoto) Synopsys DesignWare PCIe controller driver: - Extend PCI_FIND_NEXT_CAP() and PCI_FIND_NEXT_EXT_CAP() to return a pointer to the preceding Capability, to allow removal of Capabilities that are advertised but not fully implemented (Qiang Yu) - Remove MSI and MSI-X Capabilities in platforms that can't support them, so the PCI core automatically falls back to INTx (Qiang Yu) - Add ASPM L1.1 and L1.2 Substates context to debugfs ltssm_status for drivers that support this (Shawn Lin) - Skip PME_Turn_Off broadcast and L2/L3 transition during suspend if link is not up to avoid an unnecessary timeout (Manivannan Sadhasivam) - Revert dw-rockchip, qcom, and DWC core changes that used link-up IRQs to trigger enumeration instead of waiting for link to be up because the PCI core doesn't allocate bus number space for hierarchies that might be attached (Niklas Cassel) - Make endpoint iATU entry for MSI permanent instead of programming it dynamically, which is slow and racy with respect to other concurrent traffic, e.g., eDMA (Koichiro Den) - Use iMSI-RX MSI target address when possible to fix endpoints using 32-bit MSI (Shawn Lin) - Allow DWC host controller driver probe to continue if device is not found or found but inactive; only fail when there's an error with the link (Manivannan Sadhasivam) - For controllers like NXP i.MX6QP and i.MX7D, where LTSSM registers are not accessible after PME_Turn_Off, simply wait 10ms instead of polling for L2/L3 Ready (Richard Zhu) - Use multiple iATU entries to map large bridge windows and DMA ranges when necessary instead of failing (Samuel Holland) - Add EPC dynamic_inbound_mapping feature bit for Endpoint Controllers that can update BAR inbound address translation without requiring EPF driver to clear/reset the BAR first, and advertise it for DWC-based Endpoints (Koichiro Den) - Add EPC subrange_mapping feature bit for Endpoint Controllers that can map multiple independent inbound regions in a single BAR, implement subrange mapping, advertise it for DWC-based Endpoints, and add Endpoint selftests for it (Koichiro Den) - Make resizable BARs work for Endpoint multi-PF configurations; previously it only worked for PF 0 (Aksh Garg) - Fix Endpoint non-PF 0 support for BAR configuration, ATU mappings, and Address Match Mode (Aksh Garg) - Set up iATU when ECAM is enabled; previously IO and MEM outbound windows weren't programmed, and ECAM-related iATU entries weren't restored after suspend/resume, so config accesses failed (Krishna Chaitanya Chundru) Miscellaneous: - Use system_percpu_wq and WQ_PERCPU to explicitly request per-CPU work so WQ_UNBOUND can eventually be removed (Marco Crivellari)" * tag 'pci-v7.0-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (176 commits) PCI/bwctrl: Disable BW controller on Intel P45 using a quirk PCI: Disable ACS SV for IDT 0x8090 switch PCI: Disable ACS SV for IDT 0x80b5 switch PCI: Cache ACS Capabilities register PCI: Enable ACS after configuring IOMMU for OF platforms PCI: Add ACS quirk for Pericom PI7C9X2G404 switches [12d8:b404] PCI: Add ACS quirk for Qualcomm Hamoa & Glymur PCI: Use device_lock_assert() to verify device lock is held PCI: Use lockdep_assert_held(pci_bus_sem) to verify lock is held PCI: Fix pci_slot_lock () device locking PCI: Fix pci_slot_trylock() error handling PCI: Mark Nvidia GB10 to avoid bus reset PCI: Mark ASM1164 SATA controller to avoid bus reset PCI: host-generic: Avoid reporting incorrect 'missing reg property' error PCI/PME: Replace RMW of Root Status register with direct write PCI/AER: Clear stale errors on reporting agents upon probe PCI: Don't claim disabled bridge windows PCI: rzg3s-host: Fix device node reference leak in rzg3s_pcie_host_parse_port() PCI: dwc: Fix missing iATU setup when ECAM is enabled PCI: dwc: Clean up iATU index usage in dw_pcie_iatu_setup() ...
2026-02-06PCI: Don't claim disabled bridge windowsIlpo Järvinen
The commit 8278c6914306 ("PCI: Preserve bridge window resource type flags") changed bridge window resource behavior such that flags are no longer zero if the bridge window is not valid or is disabled (mainly to preserve the type flags for later use). If a bridge window has its limit smaller than base address, pci_read_bridge_*() sets both IORESOURCE_UNSET and IORESOURCE_DISABLED to indicate the bridge window exists but is not valid with the current base and limit configuration. The code in pci_claim_bridge_resources() still depends on the old behavior of checking validity of the bridge window solely based on !r->flags, whereas after 8278c6914306, also IORESOURCE_DISABLED may indicate bridge window addresses are not valid. While pci_claim_resource() does check IORESOURCE_UNSET, pci_claim_bridge_resource() attempts to clip the resource if pci_claim_resource() fails, which is not correct for bridge window resources that are not valid. As pci_bus_clip_resource() performs clipping regardless of flags and then clears IORESOURCE_UNSET, it should not be called unless the resource is valid. The problem is visible in this log: pci 0000:20:00.0: PCI bridge to [bus 21] pci 0000:20:00.0: bridge window [io size 0x0000 disabled]: can't claim; no address assigned pci 0000:20:00.0: [io 0x0000-0xffffffffffffffff disabled] clipped to [io 0x0000-0xffff disabled] Add IORESOURCE_DISABLED check in pci_claim_bridge_resources() to only claim bridge windows that appear to have a valid configuration. Fixes: 8278c6914306 ("PCI: Preserve bridge window resource type flags") Reported-by: Sizhe Liu <liusizhe5@huawei.com> Link: https://lore.kernel.org/all/20260203023545.2753811-1-liusizhe5@huawei.com Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/4d9228d6-a230-6ddf-e300-fbf42d523863@linux.intel.com
2026-01-27PCI: Separate CardBus setup & build it only with CONFIG_CARDBUSIlpo Järvinen
PCI bridge window setup code includes special code to handle CardBus bridges. CardBus has long since fallen out of favor and modern systems have no use for it. Move CardBus setup code to its own file and use existing CONFIG_CARDBUS to decide whether it should be built or not. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-18-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Add 'pci' prefix to struct pci_dev_resource handling functionsIlpo Järvinen
setup-bus.c has static functions for handling struct pci_dev_resource related operation which have no prefixes. Add 'pci' prefixes to those function names as add_to_list() will be needed in another file by an upcoming change. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-17-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Use resource_assigned() in setup-bus.c algorithmIlpo Järvinen
Many places in the resource fitting and assignment algorithm want to know if the resource is assigned into the resource tree or not. Convert open-coded ->parent checks to use resource_assigned(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-16-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Add pbus_mem_size_optional() to handle optional sizesIlpo Järvinen
The resource loop in pbus_size_mem() handles optional resources that are either fully optional (SR-IOV and disabled Expansion ROMs) or bridge windows that may be optional only for a part. The logic is a little inconsistent when it comes to a bridge window that has only optional children resources as it would be more natural to treat it similar to any fully optional resource. As resource size should be zero in that case, it shouldn't cause any bugs but it still seems useful to address the inconsistency. Place the optional size related code of pbus_size_mem() into pbus_mem_size_optional() and add a check in pci_resource_is_optional() for entirely optional bridge windows. Reorder the logic inside pbus_mem_size_optional() such that fully optional resources are handled the same irrespective of whether the resource is a bridge window or not. Additional motivation for this are the upcoming changes that add complexity to the optional sizing logic due to Resizable BAR awareness. The extra logic would exceed any reasonable indentation level if the optional sizing code is kept within the loop body. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-14-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Check invalid align earlier in pbus_size_mem()Ilpo Järvinen
Check for invalid align before any bridge window sizing actions in pbus_size_mem() to avoid need to roll back any sizing calculations. Placing the check earlier will make it easier to add more optional size related calculations at where the SR-IOV logic currently is in pbus_size_mem(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-13-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Log reset and restore of resourcesIlpo Järvinen
PCI resource fitting and assignment is complicated to track because it performs many actions without any logging. One of these is resource reset (zeroing the resource) and the restore during the multi-pass resource fitting algorithm. Resource reset does not play well with the other PCI code if the code later wants to reattempt assignment of that resource. Knowing that a resource was left in the reset state without a pairing restore is useful for understanding issues that show up as resource assignment failures. Add pci_dbg() to both reset and restore to be better able to track what's going on within the resource fitting algorithm. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-12-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Add pci_resource_is_bridge_win()Ilpo Järvinen
Add pci_resource_is_bridge_win() helper to simplify checking if the resource is a bridge window. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-11-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Fetch dev_res to local var in __assign_resources_sorted()Ilpo Järvinen
__assign_resources_sorted() calls get_res_add_size() and get_res_add_align(), each walking through the realloc_head list to relocate the corresponding pci_dev_resource entry. Fetch the pci_dev_resource entry into a local variable to avoid double walk. In addition, reverse logic to reduce indentation level. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-10-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Use res_to_dev_res() in reassign_resources_sorted()Ilpo Järvinen
reassign_resources_sorted() contains a search loop for a particular resource in the head list. res_to_dev_res() already implements the same search so use it instead. Drop unused found_match and dev_res variables. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-9-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Pass bridge window resource to pbus_size_mem()Ilpo Järvinen
pbus_size_mem() inputs type and calculates bridge window resource within. Its caller (__pci_bus_size_bridges()) also has to look up the prefetchable window to determine if it exists or not to decide whether to call pbus_size_mem() twice or once. Change the interface such that the caller is responsible in providing the bridge window resource. Passing the resource directly avoids another lookup for the prefetchable window inside pbus_size_mem(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-8-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Push realloc check into pbus_size_mem()Ilpo Järvinen
pbus_size_mem() and calculate_memsize() input both min_size and add_size. They are given the same value if realloc_head is NULL and min_size is 0 otherwise. Both are used in calculate_memsize() to enforce a lower bound to the size. The interface between __pci_bus_size_bridges() and the forementioned functions can be simplied by pushing the realloc check into pbus_size_mem(). There are only two possible cases: 1) when calculating size0, add_size parameter given to calculate_memsize() is always 0 which implies only min_size matters. 2) when calculating size1, realloc_head is not NULL which implies min_size=0 so only add_size matters. Drop min_size parameter from pbus_size_mem() and check realloc_head when calling calculate_memsize(). Drop add_size from calculate_memsize() and use only min_size within max() to enforce the lower bound. calculate_iosize() is a bit more complicated than calculate_memsize() and is therefore left as is, but pbus_size_io() can still input only min_size similar to pbus_size_mem(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-7-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Remove old_size limit from bridge window sizingIlpo Järvinen
calculate_memsize() applies lower bound to the resource size before aligning the resource size making it impossible to shrink bridge window resources. I've not found any justification for this lower bound and nothing indicated it was to work around some HW issue. Prior to the commit 3baeae36039a ("PCI: Use pci_release_resource() instead of release_resource()"), releasing a bridge window during BAR resize resulted in clearing start and end address of the resource. Clearing addresses destroys the resource size as a side-effect, therefore nullifying the effect of the old size lower bound. After the commit 3baeae36039a ("PCI: Use pci_release_resource() instead of release_resource()"), BAR resize uses the aligned old size, which results in exceeding what fits into the parent window in some cases: xe 0030:03:00.0: [drm] Attempting to resize bar from 256MiB -> 16384MiB xe 0030:03:00.0: BAR 0 [mem 0x620c000000000-0x620c000ffffff 64bit]: releasing xe 0030:03:00.0: BAR 2 [mem 0x6200000000000-0x620000fffffff 64bit pref]: releasing pci 0030:02:01.0: bridge window [mem 0x6200000000000-0x620001fffffff 64bit pref]: releasing pci 0030:01:00.0: bridge window [mem 0x6200000000000-0x6203fbff0ffff 64bit pref]: releasing pci 0030:00:00.0: bridge window [mem 0x6200000000000-0x6203fbff0ffff 64bit pref]: was not released (still contains assigned resources) pci 0030:00:00.0: Assigned bridge window [mem 0x6200000000000-0x6203fbff0ffff 64bit pref] to [bus 01-04] free space at [mem 0x6200400000000-0x62007ffffffff 64bit pref] pci 0030:00:00.0: Assigned bridge window [mem 0x6200000000000-0x6203fbff0ffff 64bit pref] to [bus 01-04] cannot fit 0x4000000000 required for 0030:01:00.0 bridging to [bus 02-04] The old size of 0x6200000000000-0x6203fbff0ffff resource was used as the lower bound which results in 0x4000000000 size request due to alignment. That exceeds what can fit into the parent window. Since the lower bound never even was enforced fully because the resource addresses were cleared when the bridge window is released, remove the old_size lower bound entirely and trust the calculated bridge window size is enough. This same problem may occur on io window side but seems less likely to cause issues due to general difference in alignment. Removing the lower bound may have other unforeseen consequences in case of io window so it's better to leave it as -next material if no problem is reported related to io window sizing (BAR resize shouldn't touch io windows anyway). Fixes: 3baeae36039a ("PCI: Use pci_release_resource() instead of release_resource()") Reported-by: Simon Richter <Simon.Richter@hogyros.de> Link: https://lore.kernel.org/r/f9a8c975-f5d3-4dd2-988e-4371a1433a60@hogyros.de/ Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-6-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Stop over-estimating bridge window sizeIlpo Järvinen
New way to calculate the bridge window head alignment produces tight-fit, that is, it does not leave any gaps between the resources. Similarly, relaxed tail alignment does not leave extra tail room. Start to use bridge window calculation that does not over-estimate the size of the required window. pbus_upstream_space_available() can be removed. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Malte Schröder <malte+lkml@tnxip.de> Link: https://patch.msgid.link/20251219174036.16738-4-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Rewrite bridge window head alignment functionIlpo Järvinen
The calculation of bridge window head alignment is done by calculate_mem_align() [*]. With the default bridge window alignment, it is used for both head and tail alignment. The selected head alignment does not always result in tight-fitting resources (gap at d4f00000-d4ffffff): d4800000-dbffffff : PCI Bus 0000:06 d4800000-d48fffff : PCI Bus 0000:07 d4800000-d4803fff : 0000:07:00.0 d4800000-d4803fff : nvme d4900000-d49fffff : PCI Bus 0000:0a d4900000-d490ffff : 0000:0a:00.0 d4900000-d490ffff : r8169 d4910000-d4913fff : 0000:0a:00.0 d4a00000-d4cfffff : PCI Bus 0000:0b d4a00000-d4bfffff : 0000:0b:00.0 d4a00000-d4bfffff : 0000:0b:00.0 d4c00000-d4c07fff : 0000:0b:00.0 d4d00000-d4dfffff : PCI Bus 0000:15 d4d00000-d4d07fff : 0000:15:00.0 d4d00000-d4d07fff : xhci-hcd d4e00000-d4efffff : PCI Bus 0000:16 d4e00000-d4e7ffff : 0000:16:00.0 d4e80000-d4e803ff : 0000:16:00.0 d4e80000-d4e803ff : ahci d5000000-dbffffff : PCI Bus 0000:0c This has not caused problems (for years) with the default bridge window tail alignment that grossly over-estimates the required tail alignment leaving more tail room than necessary. With the introduction of relaxed tail alignment that leaves no extra tail room whatsoever, any gaps will immediately turn into assignment failures. Introduce head alignment calculation that ensures no gaps are left and apply the new approach when using relaxed alignment. We may want to consider using it for the normal alignment eventually, but as the first step, solve only the problem with the relaxed tail alignment. ([*] I don't understand the algorithm in calculate_mem_align().) Link: https://git.kernel.org/history/history/c/5d0a8965aea9 ("[PATCH] 2.5.14: New PCI allocation code (alpha, arm, parisc) [2/2]") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220775 Reported-by: Malte Schröder <malte+lkml@tnxip.de> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Malte Schröder <malte+lkml@tnxip.de> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20251219174036.16738-3-ilpo.jarvinen@linux.intel.com
2026-01-26PCI: Fix bridge window alignment with optional resourcesIlpo Järvinen
pbus_size_mem() has two alignments, one for required resources in min_align and another in add_align that takes account optional resources. The add_align is applied to the bridge window through the realloc_head list. It can happen, however, that add_align is larger than min_align but calculated size1 and size0 are equal due to extra tailroom (e.g., hotplug reservation, tail alignment), and therefore no entry is created to the realloc_head list. Without the bridge appearing in the realloc head, add_align is lost when pbus_size_mem() returns. The problem is visible in this log for 0000:05:00.0 which lacks add_size ... add_align ... line that would indicate it was added into the realloc_head list: pci 0000:05:00.0: PCI bridge to [bus 06-16] ... pci 0000:06:00.0: bridge window [mem 0x00100000-0x001fffff] to [bus 07] requires relaxed alignment rules pci 0000:06:06.0: bridge window [mem 0x00100000-0x001fffff] to [bus 0a] requires relaxed alignment rules pci 0000:06:07.0: bridge window [mem 0x00100000-0x003fffff] to [bus 0b] requires relaxed alignment rules pci 0000:06:08.0: bridge window [mem 0x00800000-0x00ffffff 64bit pref] to [bus 0c-14] requires relaxed alignment rules pci 0000:06:08.0: bridge window [mem 0x01000000-0x057fffff] to [bus 0c-14] requires relaxed alignment rules pci 0000:06:08.0: bridge window [mem 0x01000000-0x057fffff] to [bus 0c-14] requires relaxed alignment rules pci 0000:06:08.0: bridge window [mem 0x01000000-0x057fffff] to [bus 0c-14] add_size 100000 add_align 1000000 pci 0000:06:0c.0: bridge window [mem 0x00100000-0x001fffff] to [bus 15] requires relaxed alignment rules pci 0000:06:0d.0: bridge window [mem 0x00100000-0x001fffff] to [bus 16] requires relaxed alignment rules pci 0000:06:0d.0: bridge window [mem 0x00100000-0x001fffff] to [bus 16] requires relaxed alignment rules pci 0000:05:00.0: bridge window [mem 0xd4800000-0xd97fffff]: assigned pci 0000:05:00.0: bridge window [mem 0x1060000000-0x10607fffff 64bit pref]: assigned pci 0000:06:08.0: bridge window [mem size 0x04900000]: can't assign; no space pci 0000:06:08.0: bridge window [mem size 0x04900000]: failed to assign While this bug itself seems old, it has likely become more visible after the relaxed tail alignment that does not grossly overestimate the size needed for the bridge window. Make sure add_align > min_align too results in adding an entry into the realloc head list. In addition, add handling to the cases where add_size is zero while only alignment differs. Fixes: d74b9027a4da ("PCI: Consider additional PF's IOV BAR alignment in sizing and assigning") Reported-by: Malte Schröder <malte+lkml@tnxip.de> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Malte Schröder <malte+lkml@tnxip.de> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20251219174036.16738-2-ilpo.jarvinen@linux.intel.com
2026-01-22PCI: Fix Resizable BAR restore orderIlpo Järvinen
The commit 337b1b566db0 ("PCI: Fix restoring BARs on BAR resize rollback path") changed BAR resize to layer rebar code and resource setup/restore code cleanly. Unfortunately, it did not consider how the value of the BAR Size field impacts the read-only bits in the Base Address Register (PCIe7 spec, sec. 7.8.6.3). That is, it very much matters in which order the BAR Size and Base Address Register are restored. Post-337b1b566db0 ("PCI: Fix restoring BARs on BAR resize rollback path") during BAR resize rollback, pci_do_resource_release_and_resize() attempts to restore the old address to the BAR that was resized, but it can fail to setup the address correctly if the address has low bits set that collide with the bits that are still read-only. As a result, kernel's resource and BAR will be out-of-sync. Fix this by restoring BAR Size before rolling back the resource changes and restoring the BAR. Fixes: 337b1b566db0 ("PCI: Fix restoring BARs on BAR resize rollback path") Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://lore.kernel.org/linux-pci/aW_w1oFQCzUxGYtu@intel.com/ Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260121131417.9582-3-ilpo.jarvinen@linux.intel.com
2026-01-22PCI: Fix BAR resize rollback path overwriting retIlpo Järvinen
The commit 337b1b566db0 ("PCI: Fix restoring BARs on BAR resize rollback path") added BAR rollback to pci_do_resource_release_and_resize() in case of resize failure. On the rollback, pci_claim_resource() is called, which can fail and the code is prepared for that possibility. pci_claim_resource()'s return value, however, overwrites the original value of ret so pci_do_resource_release_and_resize() will return an incorrect value in the end (as pci_claim_resource() normally succeeds, in practice ret will be 0). Fix the issue by directly calling pci_claim_resource() inside the if (). Fixes: 337b1b566db0 ("PCI: Fix restoring BARs on BAR resize rollback path") Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://lore.kernel.org/linux-pci/aW_w1oFQCzUxGYtu@intel.com/ Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260121131417.9582-2-ilpo.jarvinen@linux.intel.com
2025-12-04Merge tag 'pci-v6.19-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci Pull PCI updates from Bjorn Helgaas: "Enumeration: - Enable host bridge emulation for PCI_DOMAINS_GENERIC platforms (Dan Williams) - Switch vmd from custom domain number allocator to the common allocator to prevent a potential race with new non-VMD buses (Dan Williams) - Enable Precision Time Measurement (PTM) only if device advertises support for a relevant role, to prevent invalid PTM Requests that cause ACS violations that are reported as AER Uncorrectable Non-Fatal errors (Mika Westerberg) Resource management: - Prevent resource tree corruption when BAR resize fails (Ilpo Järvinen) - Restore BARs to the original size if a BAR resize fails (Ilpo Järvinen) - Remove BAR release from BAR resize attempts by the xe, i915, and amdgpu drivers so the PCI core can restore BARs if the resize fails (Ilpo Järvinen) - Move Resizable BAR code to rebar.c (Ilpo Järvinen) - Add pci_rebar_size_supported() and use it in i915 and xe (Ilpo Järvinen) - Add pci_rebar_get_max_size() and use it in xe and amdgpu (Ilpo Järvinen) Power management and error handling: - For drivers using PCI legacy suspend, save config state at suspend so that state (not any earlier state from enumeration, probe, or error recovery) will be restored when resuming (Lukas Wunner) - For devices with no driver or a driver that lacks power management, save config state at hibernate so that state (not any earlier state from enumeration, probe, or error recovery) will be restored when resuming (Lukas Wunner) - Save device config space on device addition, before driver binding, so error recovery works more reliably (Lukas Wunner) - Drop pci_save_state() from several drivers that no longer need it since the PCI core always does it and pci_restore_state() no longer invalidates the saved state (Lukas Wunner) - Document use of pci_save_state() by drivers to capture the state they want restored during error recovery (Lukas Wunner) Power control: - Add a struct pci_ops.assert_perst() function pointer to assert/deassert PCIe PERST# and implement it for the qcom driver (Krishna Chaitanya Chundru) - Add DT binding and pwrctrl driver for the Toshiba TC9563 PCIe switch, which must be held in reset after poweron so the pwrctrl driver can configure the switch via I2C before bringing up the links (Krishna Chaitanya Chundru) Endpoint framework: - Convert the endpoint doorbell test to use a threaded IRQ to fix a 'sleeping while atomic' issue (Bhanu Seshu Kumar Valluri) - Add endpoint VNTB MSI doorbell support to reduce latency between host and endpoint (Frank Li) New native PCIe controller drivers: - Add CIX Sky1 host controller DT binding and driver (Hans Zhang) - Add NXP S32G host controller DT binding and driver (Vincent Guittot) - Add Renesas RZ/G3S host controller DT binding and driver (Claudiu Beznea) - Add SpacemiT K1 host controller DT binding and driver (Alex Elder) Amlogic Meson PCIe controller driver: - Update DT binding to name DBI region 'dbi', not 'elbi', and update driver to support both (Manivannan Sadhasivam) Apple PCIe controller driver: - Move struct pci_host_bridge allocation from pci_host_common_init() to callers, which significantly simplifies pcie-apple (Marc Zyngier) Broadcom STB PCIe controller driver: - Disable advertising ASPM L0s support correctly (Jim Quinlan) - Add a panic/die handler to print diagnostic info in case PCIe caused an unrecoverable abort (Jim Quinlan) Cadence PCIe controller driver: - Add module support for Cadence platform host and endpoint controller driver (Manikandan K Pillai) - Split headers into 'legacy' (LGA) and 'high perf' (HPA) to prepare for new CIX Sky1 driver (Manikandan K Pillai) MediaTek PCIe controller driver: - Convert DT binding to YAML schema (Christian Marangi) - Add Airoha AN7583 DT compatible and driver support (Christian Marangi) Qualcomm PCIe controller driver: - Add Qualcomm Kaanapali to SM8550 DT binding (Qiang Yu) - Add required 'power-domains' and 'resets' to qcom sa8775p, sc7280, sc8280xp, sm8150, sm8250, sm8350, sm8450, sm8550, x1e80100 DT schemas (Krzysztof Kozlowski) - Look up OPP using both frequency and data rate (not just frequency) so RPMh votes can account for both (Krishna Chaitanya Chundru) Rockchip DesignWare PCIe controller driver: - Add Rockchip RK3528 compatible strings in DT binding (Yao Zi) STMicroelectronics STM32MP25 PCIe controller driver: - Fix a race between link training and endpoint register initialization (Christian Bruel) - Align endpoint allocations to match the ATU requirements (Christian Bruel) Synopsys DesignWare PCIe controller driver: - Clear L1 PM Substate Capability 'Supported' bits unless glue driver says it's supported, which prevents users from enabling non-working L1SS. Currently only qcom and tegra194 support L1SS (Bjorn Helgaas) - Remove now-superfluous L1SS disable code from tegra194 (Bjorn Helgaas) - Configure L1SS support in dw-rockchip when DT says 'supports-clkreq' (Shawn Lin) TI Keystone PCIe controller driver: - Fail the probe instead of silently succeeding if ks_pcie_of_data didn't specify Root Complex or Endpoint mode (Siddharth Vadapalli) - Make keystone buildable as a loadable module, except on ARM32 where hook_fault_code() is __init (Siddharth Vadapalli)" * tag 'pci-v6.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (100 commits) MAINTAINERS: Add Manivannan Sadhasivam as PCI/pwrctrl maintainer MAINTAINERS: Add CIX Sky1 PCIe controller driver maintainer PCI: sky1: Add PCIe host support for CIX Sky1 dt-bindings: PCI: Add CIX Sky1 PCIe Root Complex bindings PCI: cadence: Add support for High Perf Architecture (HPA) controller MAINTAINERS: Add NXP S32G PCIe controller driver maintainer PCI: s32g: Add NXP S32G PCIe controller driver (RC) PCI: dwc: Add register and bitfield definitions dt-bindings: PCI: s32g: Add NXP S32G PCIe controller PCI: Add Renesas RZ/G3S host controller driver PCI: host-generic: Move bridge allocation outside of pci_host_common_init() dt-bindings: PCI: Add Renesas RZ/G3S PCIe controller binding PCI: Validate pci_rebar_size_supported() input Documentation: PCI: Amend error recovery doc with pci_save_state() rules treewide: Drop pci_save_state() after pci_restore_state() PCI/ERR: Ensure error recoverability at all times PCI/PM: Stop needlessly clearing state_saved on enumeration and thaw PCI/PM: Reinstate clearing state_saved in legacy and !PM codepaths PCI: dw-rockchip: Configure L1SS support PCI: tegra194: Remove unnecessary L1SS disable code ...
2025-11-14PCI: Prevent restoring assigned resourcesIlpo Järvinen
restore_dev_resource() copies saved addresses and flags from the struct pci_dev_resource back to the struct resource, typically, during rollback from a failure or in preparation for a retry attempt. If the resource is within resource tree, the resource must not be modified as the resource tree could be corrupted. Thus, it's a bug to call restore_dev_resource() for assigned resources (which did happen due to logic flaws in the BAR resize rollback). Add WARN_ON_ONCE() into restore_dev_resource() to detect such bugs easily and return without altering the resource to prevent corruption. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Alex Bennée <alex.bennee@linaro.org> # AVA, AMD GPU Link: https://patch.msgid.link/20251113162628.5946-12-ilpo.jarvinen@linux.intel.com
2025-11-14PCI: Fix restoring BARs on BAR resize rollback pathIlpo Järvinen
BAR resize operation is implemented in the pci_resize_resource() and pbus_reassign_bridge_resources() functions. pci_resize_resource() can be called either from __resource_resize_store() from sysfs or directly by the driver for the Endpoint Device. The pci_resize_resource() requires that caller has released the device resources that share the bridge window with the BAR to be resized as otherwise the bridge window is pinned in place and cannot be changed. pbus_reassign_bridge_resources() rolls back resources if the resize operation fails, but rollback is performed only for the bridge windows. Because releasing the device resources are done by the caller of the BAR resize interface, these functions performing the BAR resize do not have access to the device resources as they were before the resize. pbus_reassign_bridge_resources() could try __pci_bridge_assign_resources() after rolling back the bridge windows as they were, however, it will not guarantee the resource are assigned due to differences in how FW and the kernel assign the resources (alignment of the start address and tail). To perform rollback robustly, the BAR resize interface has to be altered to also release the device resources that share the bridge window with the BAR to be resized. Also, remove restoring from the entries failed list as saved list should now contain both the bridge windows and device resources so the extra restore is duplicated work. Some drivers (currently only amdgpu) want to prevent releasing some resources. Add exclude_bars param to pci_resize_resource() and make amdgpu pass its register BAR (BAR 2 or 5), which should never be released during resize operation. Normally 64-bit prefetchable resources do not share a bridge window with the 32-bit only register BAR, but there are various fallbacks in the resource assignment logic which may make the resources share the bridge window in rare cases. This change (together with the driver side changes) is to counter the resource releases that had to be done to prevent resource tree corruption in the ("PCI: Release assigned resource before restoring them") change. As such, it likely restores functionality in cases where device resources were released to avoid resource tree conflicts which appeared to be "working" when such conflicts were not correctly detected by the kernel. Reported-by: Simon Richter <Simon.Richter@hogyros.de> Link: https://lore.kernel.org/linux-pci/f9a8c975-f5d3-4dd2-988e-4371a1433a60@hogyros.de/ Reported-by: Alex Bennée <alex.bennee@linaro.org> Link: https://lore.kernel.org/linux-pci/874irqop6b.fsf@draig.linaro.org/ Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> [bhelgaas: squash amdgpu BAR selection from https://lore.kernel.org/r/20251114103053.13778-1-ilpo.jarvinen@linux.intel.com] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Alex Bennée <alex.bennee@linaro.org> # AVA, AMD GPU Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patch.msgid.link/20251113162628.5946-7-ilpo.jarvinen@linux.intel.com
2025-11-14PCI: Free saved list without holding pci_bus_semIlpo Järvinen
Freeing the saved list does not require holding pci_bus_sem, so the critical section can be made shorter. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Alex Bennée <alex.bennee@linaro.org> # AVA, AMD GPU Link: https://patch.msgid.link/20251113162628.5946-6-ilpo.jarvinen@linux.intel.com
2025-11-14PCI: Try BAR resize even when no window was releasedIlpo Järvinen
Usually, resizing BARs requires releasing bridge windows in order to resize it to fit a larger BAR into the window. This is not always the case, however, FW could have made the window large enough to accommodate larger BAR as is, or the user might prefer to shrink a BAR to make more space for another Resizable BAR. Thus, replace the check that requires that at least one bridge window was released with a check that simply ensures bridge is not NULL. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Alex Bennée <alex.bennee@linaro.org> # AVA, AMD GPU Link: https://patch.msgid.link/20251113162628.5946-5-ilpo.jarvinen@linux.intel.com
2025-11-14PCI: Change pci_dev variable from 'bridge' to 'dev'Ilpo Järvinen
Upcoming fix to BAR resize will store also device BAR resource in the saved list. Change the pci_dev variable in the loop from 'bridge' to 'dev' as the former would be misleading with non-bridges in the list. This is in a separate change to reduce churn in the upcoming BAR resize fix. While it appears that the logic in the loop doing pci_setup_bridge() is altered as 'bridge' variable is no longer updated, a bridge should never appear more than once in the saved list so the check can only match to the first entry. As such, the code with two distinct pci_dev variables better represents the intention of the check compared with the old code where bridge variable was reused for a different purpose. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Alex Bennée <alex.bennee@linaro.org> # AVA, AMD GPU Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Link: https://patch.msgid.link/20251113162628.5946-4-ilpo.jarvinen@linux.intel.com
2025-11-14PCI: Prevent resource tree corruption when BAR resize failsIlpo Järvinen
pbus_reassign_bridge_resources() saves bridge windows into the saved list before attempting to adjust resource assignments to perform a BAR resize operation. If resource adjustments cannot be completed fully, rollback is attempted by restoring the resource from the saved list. The rollback, however, does not check whether the resources it restores were assigned by the partial resize attempt. If restore changes addresses of the resource, it can result in corrupting the resource tree. An example of a corrupted resource tree with overlapping addresses: 6200000000000-6203fbfffffff : pciex@620c3c0000000 6200000000000-6203fbff0ffff : PCI Bus 0030:01 6200020000000-62000207fffff : 0030:01:00.0 6200000000000-6203fbff0ffff : PCI Bus 0030:02 A resource that are assigned into the resource tree must remain unchanged. Thus, release such a resource before attempting to restore and claim it back. For simplicity, always do the release and claim back for the resource even in the cases where it is restored to the same address range. Note: this fix may "break" some cases where devices "worked" because the resource tree corruption allowed address space double counting to fit more resource than what can now be assigned without double counting. The upcoming changes to BAR resizing should address those scenarios (to the extent possible). Fixes: 8bb705e3e79d ("PCI: Add pci_resize_resource() for resizing BARs") Reported-by: Simon Richter <Simon.Richter@hogyros.de> Link: https://lore.kernel.org/linux-pci/67840a16-99b4-4d8c-9b5c-4721ab0970a2@hogyros.de/ Reported-by: Alex Bennée <alex.bennee@linaro.org> Link: https://lore.kernel.org/linux-pci/874irqop6b.fsf@draig.linaro.org/ Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Alex Bennée <alex.bennee@linaro.org> # AVA, AMD GPU Link: https://patch.msgid.link/20251113162628.5946-2-ilpo.jarvinen@linux.intel.com
2025-10-31PCI: Do not size non-existing prefetchable windowIlpo Järvinen
pbus_size_mem() should only be called for bridge windows that exist but __pci_bus_size_bridges() may point 'pref' to a resource that does not exist (has zero flags) in case of non-root buses. When prefetchable bridge window does not exist, the same non-prefetchable bridge window is sized more than once which may result in duplicating entries into the realloc_head list. Duplicated entries are shown in this log and trigger a WARN_ON() because realloc_head had residual entries after the resource assignment algorithm: pci 0000:00:03.0: [11ab:6820] type 01 class 0x060400 PCIe Root Port pci 0000:00:03.0: PCI bridge to [bus 00] pci 0000:00:03.0: bridge window [io 0x0000-0x0fff] pci 0000:00:03.0: bridge window [mem 0x00000000-0x000fffff] pci 0000:00:03.0: bridge window [mem 0x00200000-0x003fffff] to [bus 02] add_size 200000 add_align 200000 pci 0000:00:03.0: bridge window [mem 0x00200000-0x003fffff] to [bus 02] add_size 200000 add_align 200000 pci 0000:00:03.0: bridge window [mem 0xe0000000-0xe03fffff]: assigned pci 0000:00:03.0: PCI bridge to [bus 02] pci 0000:00:03.0: bridge window [mem 0xe0000000-0xe03fffff] ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at drivers/pci/setup-bus.c:2373 pci_assign_unassigned_root_bus_resources+0x1bc/0x234 Check resource flags of 'pref' and only size the prefetchable window if the resource has the IORESOURCE_PREFETCH flag. Fixes: ae88d0b9c57f ("PCI: Use pbus_select_window_for_type() during mem window sizing") Reported-by: Klaus Kudielka <klaus.kudielka@gmail.com> Closes: https://lore.kernel.org/r/51e8cf1c62b8318882257d6b5a9de7fdaaecc343.camel@gmail.com/ Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Klaus Kudielka <klaus.kudielka@gmail.com> Link: https://patch.msgid.link/20251027132423.8841-1-ilpo.jarvinen@linux.intel.com
2025-10-08PCI: Fix regression in pci_bus_distribute_available_resources()Yangyu Chen
The refactoring in 4292a1e45fd4 ("PCI: Refactor distributing available memory to use loops") switched pci_bus_distribute_available_resources() to operate on an array of bridge windows. That accidentally looked up bus resources via pci_bus_resource_n() and then passed those pointers to helper routines that expect the resource to belong to the device. As soon as we execute that code, pci_resource_num() warned because the resource wasn't in the bridge's resource array. This happens on my AMD Strix Halo machine with Thunderbolt device; the error message is shown below: WARNING: CPU: 6 PID: 272 at drivers/pci/pci.h:471 pci_bus_distribute_available_resources+0x6ad/0x6d0 CPU: 6 UID: 0 PID: 272 Comm: irq/33-pciehp Not tainted 6.17.0+ #1 PREEMPT(voluntary) Hardware name: PELADN YO Series/YO1, BIOS 1.04 05/15/2025 RIP: 0010:pci_bus_distribute_available_resources+0x6ad/0x6d0 Call Trace: pci_bus_distribute_available_resources+0x590/0x6d0 pci_bridge_distribute_available_resources+0x62/0xb0 pci_assign_unassigned_bridge_resources+0x65/0x1b0 pciehp_configure_device+0x92/0x160 pciehp_handle_presence_or_link_change+0x1b5/0x350 pciehp_ist+0x147/0x1c0 Fix the regression by always fetching the resource directly from the bridge with pci_resource_n(bridge, PCI_BRIDGE_RESOURCES + i). This restores the original behaviour while keeping the refactored structure. Then we can successfully assign resources to the Thunderbolt device. Fixes: 4292a1e45fd4 ("PCI: Refactor distributing available memory to use loops") Reported-by: Kenneth R. Crudup <kenny@panix.com> Closes: https://lore.kernel.org/r/dd551b81-9e81-480b-aab3-7cf8b8bbc1d0@panix.com Signed-off-by: Yangyu Chen <cyy@cyyself.name> [bhelgaas: trim timestamps, etc from commit log] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-By: Kenneth R. Crudup <kenny@panix.com> Link: https://lore.kernel.org/r/F833CC81-7C60-48FC-A31C-B9999DCC6FA2@icloud.com Link: https://patch.msgid.link/tencent_8C54420E1B0FF8D804C1B4651DF970716309@qq.com
2025-09-24PCI: Don't print stale information about resourceIlpo Järvinen
pbus_size_mem() logs the bridge window resource using pci_info() before the start and end fields of the resource have been updated which then prints stale information. Set resource addresses earlier to make understanding logs easier. Regrettably, this results in setting the addresses multiple times but that seems unavoidable. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250924135641.3399-1-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Alter misleading recursion to pci_bus_release_bridge_resources()Ilpo Järvinen
Recursing into pci_bus_release_bridge_resources() should not alter rel_type because it makes no sense to change the release type within the recursion call chain. A literal "whole_subtree" is passed into the recursion instead of "rel_type" parameter which is misleading as the release type should remain the same throughout the entire operation. This is not a correctness issue because of the preceding if () that only allows the recursion to happen if rel_type is "whole_subtree". Still, replace the non-intuitive parameter with direct passing of "rel_type". Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-25-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Pass bridge window to pci_bus_release_bridge_resources()Ilpo Järvinen
pci_bus_release_bridge_resources() takes type, which is converted into a bridge window resource in pci_bridge_release_resources(). Find out the correct bridge window for resource whose assignment failed. Pass that bridge window to pci_bus_release_bridge_resources() instead of passing the type. When recursing to subordinate, check which bridge windows have to be released and recurse for each. For now, use pbus_select_window_for_type() instead of pbus_select_window() because non-bridge window resources still have their flags reset which destroys the type information from the struct resource. The struct pci_dev_resource holds a copy of the flags which are used instead. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-24-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Add pci_setup_one_bridge_window()Ilpo Järvinen
pci_bridge_release_resources() contains a resource type hack to work around the unsuitable __pci_setup_bridge() interface. Extract the switch statement that picks the correct bridge window setup function from pci_claim_bridge_resource() into pci_setup_one_bridge_window() and use it also in pci_bridge_release_resources(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-23-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Refactor remove_dev_resources() to use pbus_select_window()Ilpo Järvinen
Convert remove_dev_resources() to use pbus_select_window(). As 'available' is not the real resources, the index has to be adjusted as only bridge resource counterparts are present in the 'available' array. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-22-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Refactor distributing available memory to use loopsIlpo Järvinen
pci_bus_distribute_available_resources() and pci_bridge_distribute_available_resources() retain bridge window resources and related data needed for distributing the available window in independent variables for io, memory, and prefetchable memory windows. The code is essentially the same for all of them and therefore repeated three times with different variable names. Refactor pci_bus_distribute_available_resources() to take an array. This is complicated slightly by the function taking advantage of passing the struct as value, which cannot be done for arrays in C. Therefore, copy the data into a local array in the stack in the first loop. Variable names are (hopefully) improved slightly as well. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-21-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Use pbus_select_window_for_type() during mem window sizingIlpo Järvinen
__pci_bus_size_bridges() goes to great lengths of helping pbus_size_mem() in which types it should put into a particular bridge window, requiring passing up to three resource type into pbus_size_mem(). Instead of having complex logic in __pci_bus_size_bridges() and a non-straightforward interface between those functions, use pbus_select_window_for_type() and pbus_select_window() to find the correct bridge window and compare if the resources belong to that window. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-20-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Use pbus_select_window() in space available checkerIlpo Järvinen
pbus_upstream_space_available() figures out the upstream bridge window resources on its own. Migrate it to use pbus_select_window(). Note: pbus_select_window() -> pbus_select_window_for_type() calls find_bus_resource_of_type() for root bus, which does not do parent check similar to what pbus_upstream_space_available() did earlier, but the difference does not matter because pbus_upstream_space_available() itself stops when it encounters the root bus. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-19-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Rename resource variable from r to resIlpo Järvinen
Resource is going to be passed in as argument aften an upcoming change. Rename the struct resource variable from "r" to "res" to avoid using one letter variable name in a function argument. This rename is made separately to reduce churn in the upcoming change. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-18-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Use pbus_select_window_for_type() during IO window sizingIlpo Järvinen
Convert pbus_size_io() to use pbus_select_window_for_type(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-17-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Warn if bridge window cannot be released when resizing BARIlpo Järvinen
BAR resizing calls to pci_reassign_bridge_resources(), which attempts to release any upstream bridge window to allow them to accommodate the new BAR size. The release can only be performed if there are no other child resources for the bridge window. Previously the code continued silently when other child resources were detected. Add pci_warn() to inform user that a bridge window could not be released because of child resources. As a small bridge window is often the reason why BAR resize fails, this warning will help to pinpoint to the cause. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-15-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Fix finding bridge window in pci_reassign_bridge_resources()Ilpo Järvinen
pci_reassign_bridge_resources() walks upwards in the PCI bus hierarchy, locates the relevant bridge window on each level using flags check, and attempts to release the bridge window. The flags-based check is fragile due to various fallbacks in the bridge window selection logic. As such, the algorithm might not locate the correct bridge window. Refactor pci_reassign_bridge_resources() to determine the correct bridge window using pbus_select_window(), which contains logic to handle all fallback cases correctly. Change function prefix to pbus as it now inputs struct bus and resource for which to locate the bridge window. The main purpose is to make bridge window selection logic consistent across the entire PCI core (one step at a time). While this technically also fixes the commit 8bb705e3e79d ("PCI: Add pci_resize_resource() for resizing BARs") making the bridge window walk algorithm more robust, the normal setup having a 64-bit resizable BAR underneath bridge(s) with 64-bit prefetchable windows does not need to use any fallbacks. As such, the practical impact is low (requiring BAR resize use case and a non-typical bridge device). The way to detect if unrelated resource failed again is left to use the type based approximation which should not behave worse than before. Fixes: 8bb705e3e79d ("PCI: Add pci_resize_resource() for resizing BARs") Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-14-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Add bridge window selection functionsIlpo Järvinen
Various places in the PCI core code independently decide into which bridge window a child resource should be placed. It is hard to see whether these decisions always end up in agreement, especially in the corner cases, and in some places it requires complex logic to pass multiple resource types and/or bridge windows around. Add pbus_select_window() and pbus_select_window_for_type() for cases where the former cannot be used so that eventually the same helper can be used to select the bridge window everywhere. Using the same function ensures the selected bridge window remains always the same and it can be easily recalculated in-situ allowing simplifying the interfaces between internal functions in upcoming changes. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-13-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Preserve bridge window resource type flagsIlpo Järvinen
When a bridge window is found unused or fails to assign, the flags of the associated resource are cleared. Clearing flags is problematic as it also removes the type information of the resource which is needed later. Thus, always preserve the bridge window type flags and use IORESOURCE_UNSET and IORESOURCE_DISABLED to indicate the status of the bridge window. Also, when initializing resources, make sure all valid bridge windows do get their type flags set. Change various places that relied on resource flags being cleared to check for IORESOURCE_UNSET and IORESOURCE_DISABLED to allow bridge window resource to retain their type flags. Add pdev_resource_assignable() and pdev_resource_should_fit() helpers to filter out disabled bridge windows during resource fitting; the latter combines more common checks into the helper. When reading the bridge windows from the registers, instead of leaving the resource flags cleared for bridge windows that are not enabled, always set up the flags and set IORESOURCE_UNSET | IORESOURCE_DISABLED as needed. When resource fitting or assignment fails for a bridge window resource, or the bridge window is not needed, mark the resource with IORESOURCE_UNSET or IORESOURCE_DISABLED, respectively. Use dummy zero resource in resource_show() for backwards compatibility as lspci will otherwise misrepresent disabled bridge windows. This change fixes an issue which highlights the importance of keeping the resource type flags intact: At the end of __assign_resources_sorted(), reset_resource() is called, previously clearing the flags. Later, pci_prepare_next_assign_round() attempted to release bridge resources using pci_bus_release_bridge_resources() that calls into pci_bridge_release_resources() that assumes type flags are still present. As type flags were cleared, IORESOURCE_MEM_64 was not set leading to resources under an incorrect bridge window to be released (idx = 1 instead of idx = 2). While the assignments performed later covered this problem so that the wrongly released resources got assigned in the end, it was still causing extra release+assign pairs. There are other reasons why the resource flags should be retained in upcoming changes too. Removing the flag reset for non-bridge window resource is left as future work, in part because it has a much higher regression potential due to pci_enable_resources() that will start to work also for those resources then and due to what endpoint drivers might assume about resources. Despite the Fixes tag, backporting this (at least any time soon) is highly discouraged. The issue fixed is borderline cosmetic as the later assignments normally cover the problem entirely. Also there might be non-obvious dependencies. Fixes: 5b28541552ef ("PCI: Restrict 64-bit prefetchable bridge windows to 64-bit resources") Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-11-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Use pci_release_resource() instead of release_resource()Ilpo Järvinen
A few places in setup-bus.c call release_resource() directly and end up duplicating functionality from pci_release_resource() such as parent check, logging, and clearing the resource. Worse yet, the way the resource is cleared is inconsistent between different sites. Convert release_resource() calls into pci_release_resource() to remove code duplication. This will also make the resource start, end, and flags behavior consistent, i.e., start address is cleared, and only IORESOURCE_UNSET is asserted for the resource. While at it, eliminate the unnecessary initialization of idx variable in pci_bridge_release_resources(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-9-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Disable non-claimed bridge windowIlpo Järvinen
If clipping or claiming the bridge window fails, the bridge window is left in a state that does not match the kernel's view on what the bridge window is. Disable the bridge window by writing the magic disable value into the Base and Limit Registers if clipping or claiming failed. To detect if claiming the resource was successful, add res->parent checks into the bridge setup functions. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-8-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Always claim bridge window before its setupIlpo Järvinen
When the claim of a resource fails for the full range in pci_claim_bridge_resource(), clipping the resource to a smaller size is attempted. If clipping is successful, the new bridge window is programmed and only as the last step the code attempts to claim the resource again. The order of the last two steps is slightly illogical and inconsistent with the assignment call chains. If claiming the bridge window after clipping fails, the bridge window that was set up is left in place. Rework the logic such that the bridge window is claimed before calling the relevant bridge setup function. This make the behavior consistent with resource fitting call chains that always assign the bridge window before programming it. If claiming the bridge window fails, the clipped bridge window is no longer set up but pci_claim_bridge_resource() returns without writing the bridge window at all. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-7-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Refactor find_bus_resource_of_type() logic checksIlpo Järvinen
Reorder the logic checks in find_bus_resource_of_type() to simplify them. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-6-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Move find_bus_resource_of_type() earlierIlpo Järvinen
Move find_bus_resource_of_type() earlier in setup-bus.c to be able to call it in upcoming changes. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20250829131113.36754-5-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Fix failure detection during resource resizeIlpo Järvinen
Since 96336ec70264 ("PCI: Perform reset_resource() and build fail list in sync") the failed list is always built and returned to let the caller decide what to do with the failures. The caller may want to retry resource fitting and assignment and before that can happen, the resources should be restored to their original state (a reset effectively clears the struct resource), which requires returning them to the failed list so the original state remains stored in the associated struct pci_dev_resource. Resource resizing is different from the ordinary resource fitting and assignment in that it only considers part of the resources. This means failures for other resource types are not relevant at all and should be ignored. As resize doesn't unassign such unrelated resources, those resources ending up in the failed list implies assignment of that resource must have failed before resize too. The check in pci_reassign_bridge_resources() to decide if the whole assignment is successful, however, is based on list emptiness which will cause false negatives when the failed list has resources with an unrelated type. If the failed list is not empty, call pci_required_resource_failed() and extend it to be able to filter on specific resource types too (if provided). Calling pci_required_resource_failed() at this point is slightly problematic because the resource itself is reset when the failed list is constructed in __assign_resources_sorted(). As a result, pci_resource_is_optional() does not have access to the original resource flags. This could be worked around by restoring and re-resetting the resource around the call to pci_resource_is_optional(), however, it shouldn't cause issue as resource resizing is meant for 64-bit prefetchable resources according to Christian König (see the Link which unfortunately doesn't point directly to Christian's reply because lore didn't store that email at all). Fixes: 96336ec70264 ("PCI: Perform reset_resource() and build fail list in sync") Link: https://lore.kernel.org/all/c5d1b5d8-8669-5572-75a7-0b480f581ac1@linux.intel.com/ Reported-by: D Scott Phillips <scott@os.amperecomputing.com> Closes: https://lore.kernel.org/all/86plf0lgit.fsf@scott-ph-mail.amperecomputing.com/ Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: D Scott Phillips <scott@os.amperecomputing.com> Reviewed-by: D Scott Phillips <scott@os.amperecomputing.com> Cc: Christian König <christian.koenig@amd.com> Cc: stable@vger.kernel.org # v6.15+ Link: https://patch.msgid.link/20250822123359.16305-4-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Fix pdev_resources_assignable() disparityIlpo Järvinen
pdev_sort_resources() uses pdev_resources_assignable() helper to decide if device's resources cannot be assigned, so it ignores class 0 (PCI_CLASS_NOT_DEFINED) devices. pbus_size_mem(), on the other hand, does not do the same check. This could lead into a situation where a resource ends up on realloc_head list but is not on the head list, which in turn prevents emptying the resource from the realloc_head list in __assign_resources_sorted(). A non-empty realloc_head is unacceptable because it triggers an internal sanity check as shown in this log with a device that has class 0 (PCI_CLASS_NOT_DEFINED): pci 0001:01:00.0: [144d:a5a5] type 00 class 0x000000 PCIe Endpoint pci 0001:01:00.0: BAR 0 [mem 0x00000000-0x000fffff 64bit] pci 0001:01:00.0: ROM [mem 0x00000000-0x0000ffff pref] pcieport 0001:00:00.0: bridge window [mem 0x00100000-0x001fffff] to [bus 01-ff] add_size 100000 add_align 100000 pcieport 0001:00:00.0: bridge window [mem 0x40000000-0x401fffff]: assigned ------------[ cut here ]------------ kernel BUG at drivers/pci/setup-bus.c:2532! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP ... Call trace: pci_assign_unassigned_bus_resources+0x110/0x114 (P) pci_rescan_bus+0x28/0x48 Use pdev_resources_assignable() also within pbus_size_mem() to skip processing of non-assignable resources which removes the disparity in between what resources pdev_sort_resources() and pbus_size_mem() consider. As non-assignable resources are no longer processed, they are not added to the realloc_head list, thus the sanity check no longer triggers. This disparity problem is very old but only now became apparent after 2499f5348431 ("PCI: Rework optional resource handling") that made the ROM resources optional when calculating bridge window sizes which required adding the resource to the realloc_head list. Previously, bridge windows were just sized larger than necessary. Fixes: 2499f5348431 ("PCI: Rework optional resource handling") Reported-by: Tudor Ambarus <tudor.ambarus@linaro.org> Closes: https://lore.kernel.org/all/5f103643-5e1c-43c6-b8fe-9617d3b5447c@linaro.org/ Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: stable@vger.kernel.org # v6.15+ Link: https://patch.msgid.link/20250822123359.16305-3-ilpo.jarvinen@linux.intel.com
2025-09-16PCI: Ensure relaxed tail alignment does not increase min_alignIlpo Järvinen
When using relaxed tail alignment for the bridge window, pbus_size_mem() also tries to minimize min_align, which can under certain scenarios end up increasing min_align from that found by calculate_mem_align(). Ensure min_align is not increased by the relaxed tail alignment. Eventually, it would be better to add calculate_relaxed_head_align() similar to calculate_mem_align() which finds out what alignment can be used for the head without introducing any gaps into the bridge window to give flexibility on head address too. But that looks relatively complex so it requires much more testing than fixing the immediate problem causing a regression. Fixes: 67f9085596ee ("PCI: Allow relaxed bridge window tail sizing for optional resources") Reported-by: Rio Liu <rio@r26.me> Closes: https://lore.kernel.org/all/o2bL8MtD_40-lf8GlslTw-AZpUPzm8nmfCnJKvS8RQ3NOzOW1uq1dVCEfRpUjJ2i7G2WjfQhk2IWZ7oGp-7G-jXN4qOdtnyOcjRR0PZWK5I=@r26.me/ Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Rio Liu <rio@r26.me> Cc: stable@vger.kernel.org # v6.15+ Link: https://patch.msgid.link/20250822123359.16305-2-ilpo.jarvinen@linux.intel.com