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path: root/drivers/pci
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2026-01-30PCI: dwc: ep: Fix resizable BAR support for multi-PF configurationsAksh Garg
The resizable BAR support added by the commit 3a3d4cabe681 ("PCI: dwc: ep: Allow EPF drivers to configure the size of Resizable BARs") incorrectly configures the resizable BARs only for the first Physical Function (PF0) in EP mode. The resizable BAR configuration functions use generic dw_pcie_*_dbi() operations instead of physical function specific dw_pcie_ep_*_dbi() operations. This causes resizable BAR configuration to always target PF0 regardless of the requested function number. Additionally, dw_pcie_ep_init_non_sticky_registers() only initializes resizable BAR registers for PF0, leaving other PFs unconfigured during the execution of this function. Fix this by using physical function specific configuration space access operations throughout the resizable BAR code path and initializing registers for all the physical functions that support resizable BARs. Fixes: 3a3d4cabe681 ("PCI: dwc: ep: Allow EPF drivers to configure the size of Resizable BARs") Signed-off-by: Aksh Garg <a-garg7@ti.com> [mani: added stable tag] Signed-off-by: Manivannan Sadhasivam <mani@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Niklas Cassel <cassel@kernel.org> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260130115516.515082-2-a-garg7@ti.com
2026-01-30PCI: endpoint: pci-epf-test: Allow overriding default BAR sizesNiklas Cassel
Add bar{0,1,2,3,4,5}_size attributes in configfs, so that the user is not restricted to run pci-epf-test with the hardcoded BAR size values defined in pci-epf-test.c. This code is shamelessly more or less copy pasted from pci-epf-vntb.c Signed-off-by: Niklas Cassel <cassel@kernel.org> Signed-off-by: Manivannan Sadhasivam <mani@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Koichiro Den <den@valinux.co.jp> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260130113038.2143947-2-cassel@kernel.org
2026-01-29PCI: endpoint: pci-epf-test: Add BAR subrange mapping test supportKoichiro Den
Extend pci-epf-test so that pci_endpoint_test can exercise BAR subrange mapping end-to-end. Add BAR_SUBRANGE_SETUP/CLEAR commands that program (and tear down) a simple 2-subrange layout for a selected BAR. The endpoint deliberately permutes the physical backing regions (swap the halves) and writes a deterministic signature byte per subrange. This allows the RC to verify that the submap order is actually applied, not just that reads/writes work with an identity mapping. Advertise CAP_SUBRANGE_MAPPING only when the underlying EPC supports dynamic_inbound_mapping and subrange_mapping. Also bump the default BAR sizes (BAR0-4) to 128 KiB so that split subranges are large enough to satisfy common inbound-translation alignment constraints. E.g. for DWC EP, the default and maximum CX_ATU_MIN_REGION_SIZE is 64 kB, so 128 KiB is sufficient for DWC-based EP platforms for 2-subrange testing. Signed-off-by: Koichiro Den <den@valinux.co.jp> Signed-off-by: Manivannan Sadhasivam <mani@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20260124145012.2794108-7-den@valinux.co.jp
2026-01-29PCI: dwc: ep: Support BAR subrange inbound mapping via Address Match Mode iATUKoichiro Den
Extend dw_pcie_ep_set_bar() to support inbound mappings for BAR subranges using Address Match Mode IB iATU when pci_epf_bar.num_submap is non-zero. Rename the existing BAR-match helper into dw_pcie_ep_ib_atu_bar() and introduce dw_pcie_ep_ib_atu_addr() for Address Match Mode. When num_submap is non-zero, read the assigned BAR base address and program one inbound iATU window per subrange. Validate the submap array before programming: - each subrange is aligned to pci->region_align - subranges cover the whole BAR (no gaps and no overlaps) Track Address Match Mode mappings and tear them down on clear_bar() and on set_bar() error paths to avoid leaving half-programmed state or untranslated BAR holes. Advertise this capability by extending the common feature bit initializer macro (DWC_EPC_COMMON_FEATURES). This enables multiple inbound windows within a single BAR, which is useful on platforms where usable BARs are scarce but EPFs need multiple inbound regions. Signed-off-by: Koichiro Den <den@valinux.co.jp> Signed-off-by: Manivannan Sadhasivam <mani@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Reviewed-by: Niklas Cassel <cassel@kernel.org> Link: https://patch.msgid.link/20260124145012.2794108-5-den@valinux.co.jp
2026-01-29PCI/pwrctrl: Create pwrctrl device if graph port is foundManivannan Sadhasivam
The devicetree node of the PCIe Root Port/Slot could have the graph port to link the PCIe M.2 connector node. Since the M.2 connectors are modeled as Power Sequencing devices, they need to be controlled by the pwrctrl driver like the Root Port/Slot supplies. Hence, create the pwrctrl device if the graph port is found in the node. Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Link: https://patch.msgid.link/20260128-pci-m2-v7-2-9b3a5fe3d244@oss.qualcomm.com
2026-01-29PCI: Check parent for NULL in of_pci_bus_release_domain_nr()Sergey Shtylyov
of_pci_bus_find_domain_nr() allows its parent parameter to be NULL but of_pci_bus_release_domain_nr() (that undoes its effect) doesn't -- that means it's going to blow up while calling of_get_pci_domain_nr() if the parent parameter indeed happens to be NULL. Add the missing NULL check. Found by Linux Verification Center (linuxtesting.org) with the Svace static analysis tool. Fixes: c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()") Signed-off-by: Sergey Shtylyov <s.shtylyov@auroraos.dev> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20260127203944.28588-1-s.shtylyov@auroraos.dev
2026-01-28PCI/pwrctrl: Add PCIe M.2 connector supportManivannan Sadhasivam
Add support for handling PCIe M.2 connectors as Power Sequencing devices. These connectors are exposed as Power Sequencing devices as they often support multiple interfaces like PCIe/SATA, USB/UART to the host machine, and the interfaces may be driven by different client drivers at the same time. This driver handles the PCIe interface of these connectors. It first checks for the presence of the graph port in the Root Port node with the help of of_graph_is_present() API. If present, it acquires/powers ON the corresponding pwrseq device. Once the pwrseq device is powered ON, the driver will skip parsing the Root Port/Slot resources and register with the pwrctrl framework. Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Link: https://patch.msgid.link/20260128-pci-m2-v7-1-9b3a5fe3d244@oss.qualcomm.com
2026-01-28PCI: dwc: Advertise dynamic inbound mapping supportKoichiro Den
The DesignWare EP core has supported updating the inbound iATU mapping for an already configured BAR (i.e. allowing pci_epc_set_bar() to be called again without a prior pci_epc_clear_bar()) since commit 4284c88fff0e ("PCI: designware-ep: Allow pci_epc_set_bar() update inbound map address"). Now that this capability is exposed via the dynamic_inbound_mapping EPC feature bit, set it for DWC-based EP glue drivers using a common initializer macro to avoid duplicating the same flag in each driver. Note that pci-layerscape-ep.c is untouched. It currently constructs the feature struct dynamically in ls_pcie_ep_init(). Once converted to a static feature definition, it will use DWC_EPC_COMMON_FEATURES as well. Signed-off-by: Koichiro Den <den@valinux.co.jp> Signed-off-by: Manivannan Sadhasivam <mani@kernel.org> Reviewed-by: Niklas Cassel <cassel@kernel.org> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260124145012.2794108-4-den@valinux.co.jp
2026-01-28PCI: endpoint: Add BAR subrange mapping supportKoichiro Den
Some endpoint platforms have only a small number of usable BARs. At the same time, EPF drivers (e.g. vNTB) may need multiple independent inbound regions (control/scratchpad, one or more memory windows, and optionally MSI or other feature-related regions). Subrange mapping allows these to share a single BAR without consuming additional BARs that may not be available, or forcing a fragile layout by aggressively packing into a single contiguous memory range. Extend the PCI endpoint core to support mapping subranges within a BAR. Add an optional 'submap' field in struct pci_epf_bar so an endpoint function driver can request inbound mappings that fully cover the BAR. Introduce a new EPC feature bit, subrange_mapping, and reject submap requests from pci_epc_set_bar() unless the controller advertises both subrange_mapping and dynamic_inbound_mapping features. The submap array describes the complete BAR layout (no overlaps and no gaps are allowed to avoid exposing untranslated address ranges). This provides the generic infrastructure needed to map multiple logical regions into a single BAR at different offsets, without assuming a controller-specific inbound address translation mechanism. Signed-off-by: Koichiro Den <den@valinux.co.jp> Signed-off-by: Manivannan Sadhasivam <mani@kernel.org> Reviewed-by: Niklas Cassel <cassel@kernel.org> Link: https://patch.msgid.link/20260124145012.2794108-3-den@valinux.co.jp
2026-01-27PCI: Move CardBus bridge scanning to setup-cardbus.cIlpo Järvinen
The PCI core's pci_scan_bridge_extend() contains convoluted logic specific to setting up bus numbers for legacy CardBus bridges. Extract the CardBus specific part out into setup-cardbus.c to make the core code cleaner and allow omitting CardBus bridge support from modern systems. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-24-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Add pbus_validate_busn() for Bus Number validationIlpo Järvinen
pci_scan_bridge_extend() validates bus numbers but upcoming changes that separate CardBus code into own function need to call that the same validation. Thus, add pbus_validate_busn for validating the Bus Numbers. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-23-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Add dword #defines for Bus Number + Secondary Latency TimerIlpo Järvinen
uapi/linux/pci_regs.h defines Primary/Secondary/Subordinate Bus Numbers and Secondary Latency Timer (PCIe r7.0, sec. 7.5.1.3) as byte register offsets, but in practice the code may read/write the entire dword. In the lack of #defines to handle the dword fields, the code ends up using literals which are not as easy to read. Add dword field masks for the Bus Number and Secondary Latency Timer fields and use them in probe.c. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> [bhelgaas: squash new #defines and uses together] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-21-ilpo.jarvinen@linux.intel.com Link: https://patch.msgid.link/20251219174036.16738-22-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Use scnprintf() instead of sprintf()Ilpo Järvinen
Using sprintf() is deprecated as it does not do proper size checks. While the code in pci_scan_bridge_extend() is safe with respect to overwriting the destination buffer, use scnprintf() to not promote use of a deprecated sprint() (and allow eventually removing it from the kernel). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-20-ilpo.jarvinen@linux.intel.com
2026-01-27PCI: Handle CardBus-specific params in setup-cardbus.cIlpo Järvinen
Move CardBus window sizing parameters to setup-cardbus.c, which contains all the other CardBus code. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20251219174036.16738-19-ilpo.jarvinen@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
2026-01-27irqchip/gic-v5: Add ACPI ITS probingLorenzo Pieralisi
On ACPI ARM64 systems the GICv5 ITS configuration and translate frames are described in the MADT table. Refactor the current GICv5 ITS driver code to share common functions between ACPI and OF and implement ACPI probing in the GICv5 ITS driver. Add iort_msi_xlate() to map a device ID and retrieve an MSI controller fwnode node for ACPI systems and update pci_msi_map_rid_ctlr_node() to use it in its ACPI code path. Add the required functions to IORT code for deviceID retrieval and IRQ domain registration and look-up so that the GICv5 ITS driver in an ACPI based system can be successfully probed. Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Acked-by: Thomas Gleixner <tglx@kernel.org> Link: https://patch.msgid.link/20260115-gicv5-host-acpi-v3-5-c13a9a150388@kernel.org Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2026-01-27PCI/MSI: Make the pci_msi_map_rid_ctlr_node() interface firmware agnosticLorenzo Pieralisi
To support booting with OF and ACPI seamlessly, GIC ITS parent code requires the PCI/MSI irqdomain layer to implement a function to retrieve an MSI controller fwnode and map an RID in a firmware agnostic way (ie pci_msi_map_rid_ctlr_node()). Convert pci_msi_map_rid_ctlr_node() to an OF agnostic interface (fwnode_handle based) and update the GIC ITS MSI parent code to reflect the pci_msi_map_rid_ctlr_node() change. Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Thomas Gleixner <tglx@kernel.org> Link: https://patch.msgid.link/20260115-gicv5-host-acpi-v3-2-c13a9a150388@kernel.org Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@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
2026-01-26PCI/MSI: Unmap MSI-X region on errorHaoxiang Li
msix_capability_init() fails to unmap the MSI-X region if msix_setup_interrupts() fails. Add the missing iounmap() for that error path. [ tglx: Massaged change log ] Signed-off-by: Haoxiang Li <lihaoxiang@isrc.iscas.ac.cn> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Link: https://patch.msgid.link/20260125144452.2103812-1-lihaoxiang@isrc.iscas.ac.cn
2026-01-23PCI: endpoint: Fix swapped parameters in ↵Manikanta Maddireddy
pci_{primary/secondary}_epc_epf_unlink() functions struct configfs_item_operations callbacks are defined like the following: int (*allow_link)(struct config_item *src, struct config_item *target); void (*drop_link)(struct config_item *src, struct config_item *target); While pci_primary_epc_epf_link() and pci_secondary_epc_epf_link() specify the parameters in the correct order, pci_primary_epc_epf_unlink() and pci_secondary_epc_epf_unlink() specify the parameters in the wrong order, leading to the below kernel crash when using the unlink command in configfs: Unable to handle kernel paging request at virtual address 0000000300000857 Mem abort info: ... pc : string+0x54/0x14c lr : vsnprintf+0x280/0x6e8 ... string+0x54/0x14c vsnprintf+0x280/0x6e8 vprintk_default+0x38/0x4c vprintk+0xc4/0xe0 pci_epf_unbind+0xdc/0x108 configfs_unlink+0xe0/0x208+0x44/0x74 vfs_unlink+0x120/0x29c __arm64_sys_unlinkat+0x3c/0x90 invoke_syscall+0x48/0x134 do_el0_svc+0x1c/0x30prop.0+0xd0/0xf0 Fixes: e85a2d783762 ("PCI: endpoint: Add support in configfs to associate two EPCs with EPF") Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com> [mani: cced stable, changed commit message as per https://lore.kernel.org/linux-pci/aV9joi3jF1R6ca02@ryzen] Signed-off-by: Manivannan Sadhasivam <mani@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Niklas Cassel <cassel@kernel.org> Reviewed-by: Frank Li <Frank.Li@nxp.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260108062747.1870669-1-mmaddireddy@nvidia.com
2026-01-23Merge tag 'pci-v6.19-fixes-4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci Pull PCI fixes from Bjorn Helgaas: - Fix the pci_do_resource_release_and_resize() failure path, which clobbered the intended failure return value (Ilpo Järvinen) - Restore resizable BAR size before value because the size determines which bits are writable; this fixes i915 and xe regressions (Ilpo Järvinen) * tag 'pci-v6.19-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: PCI: Fix Resizable BAR restore order PCI: Fix BAR resize rollback path overwriting ret
2026-01-23PCI: dwc: Rename dw_pcie_rp::has_msi_ctrl to dw_pcie_rp::use_imsi_rx for clarityQiang Yu
The current "has_msi_ctrl" flag name is misleading because it suggests the presence of any MSI controller, while it is specifically set for platforms that lack .msi_init() callback and don't have "msi-parent" or "msi-map" device tree properties, indicating they rely on the iMSI-RX module for MSI functionality. Rename it to "use_imsi_rx" to make the intent clear: - When true: Platform uses the iMSI-RX module for MSI handling - When false: Platform has other MSI controller support (ITS/MBI, external MSI controller) No functional changes, only improves code readability and eliminates naming confusion. Signed-off-by: Qiang Yu <qiang.yu@oss.qualcomm.com> [mani: renamed 'uses_imsi_rx' to 'use_imsi_rx' per https://lore.kernel.org/linux-pci/09f9acc1-d1ad-4971-8488-f0268cf08799@rock-chips.com] Signed-off-by: Manivannan Sadhasivam <mani@kernel.org> Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com> Link: https://patch.msgid.link/20260121-remove_cap_clean_up-v1-2-e78115e5d467@oss.qualcomm.com
2026-01-23PCI: dwc: Fix grammar and formatting for comment in ↵Qiang Yu
dw_pcie_remove_ext_capability() Fix a grammatical error in the comment by changing "it's" to "its". Also add a blank line after the variable declaration for better code formatting. Signed-off-by: Qiang Yu <qiang.yu@oss.qualcomm.com> Signed-off-by: Manivannan Sadhasivam <mani@kernel.org> Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com> Link: https://patch.msgid.link/20260121-remove_cap_clean_up-v1-1-e78115e5d467@oss.qualcomm.com
2026-01-22PCI/IDE: Fix reading a wrong reg for unused sel stream initializationLi Ming
During pci_ide_init(), it will write PCI_ID_RESERVED_STREAM_ID into all unused selective IDE stream blocks. In a selective IDE stream block, IDE stream ID field is in selective IDE stream control register instead of selective IDE stream capability register. Fixes: 079115370d00 ("PCI/IDE: Initialize an ID for all IDE streams") Signed-off-by: Li Ming <ming.li@zohomail.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Xu Yilun <yilun.xu@linux.intel.com> Link: https://patch.msgid.link/20260111073823.486665-1-ming.li@zohomail.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2026-01-22PCI/IDE: Fix off by one error calculating VF RID rangeLi Ming
The VF ID range of an SR-IOV device is [0, num_VFs - 1]. pci_ide_stream_alloc() mistakenly uses num_VFs to represent the last ID. Fix that off by one error to stay in bounds of the range. Fixes: 1e4d2ff3ae45 ("PCI/IDE: Add IDE establishment helpers") Signed-off-by: Li Ming <ming.li@zohomail.com> Reviewed-by: Xu Yilun <yilun.xu@linux.intel.com> Link: https://patch.msgid.link/20260114111455.550984-1-ming.li@zohomail.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2026-01-22Revert "PCI/TSM: Report active IDE streams"Dan Williams
The proposed ABI failed to account for multiple host bridges with the same stream name. The fix needs to namespace streams or otherwise link back to the host bridge, but a change like that is too big for a fix. Given this ABI never saw a released kernel, delete it for now and bring it back later with this issue addressed. Reported-by: Xu Yilun <yilun.xu@linux.intel.com> Reported-by: Yi Lai <yi1.lai@intel.com> Closes: http://lore.kernel.org/20251223085601.2607455-1-yilun.xu@linux.intel.com Link: http://patch.msgid.link/6972c872acbb9_1d3310035@dwillia2-mobl4.notmuch Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2026-01-22PCI/AER: Update struct aer_err_info with kernel-doc formattingTerry Bowman
Update the existing 'struct aer_err_info' definition to use kernel-doc formatting. Remove the inline comments to reduce noise and do not introduce functional changes. This will improve readability and maintainability. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Link: https://patch.msgid.link/20260114182055.46029-16-terry.bowman@amd.com Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22PCI/AER: Report CXL or PCIe bus type in AER trace loggingTerry Bowman
The AER service driver and aer_event tracing currently log 'PCIe Bus Type' for all errors. Update the driver and aer_event tracing to log 'CXL Bus Type' for CXL device errors. This requires that AER can identify and distinguish between PCIe errors and CXL errors. Introduce boolean 'is_cxl' to 'struct aer_err_info'. Add assignment in aer_get_device_error_info() and pci_print_aer(). Update the aer_event trace routine to accept a bus type string parameter. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Co-developed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Link: https://patch.msgid.link/20260114182055.46029-15-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22PCI/AER: Use guard() in cxl_rch_handle_error_iter()Terry Bowman
cxl_rch_handle_error_iter() includes a call to device_lock() using a goto for multiple return paths. Improve readability and maintainability by using the guard() lock variant. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20260114182055.46029-13-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22PCI/AER: Move CXL RCH error handling to aer_cxl_rch.cTerry Bowman
The Restricted CXL Host (RCH) AER error handling logic currently resides in the AER driver file, aer.c. CXL specific changes conditionally compiled using #ifdefs. Improve the AER driver maintainability by separating the RCH specific logic from the AER driver's core functionality and removing the ifdefs. Introduce drivers/pci/pcie/aer_cxl_rch.c for moving the RCH AER logic into. Conditionally compile the file using the CONFIG_CXL_RCH_RAS Kconfig. Move the CXL logic into the new file but leave CXL helper function is_internal_error() in aer.c for now as it will be moved in future patch for CXL Virtual Hierarchy handling. To maintain compilation after the move other changes are required. Change cxl_rch_handle_error(), cxl_rch_enable_rcec(), and is_internal_error() to be non-static inorder for accessing from the AER driver. Update the new file with the SPDX and 2023 AMD copyright notations because the RCH bits were initially contributed in 2023 by AMD. See commit: commit 0a867568bb0d ("PCI/AER: Forward RCH downstream port-detected errors to the CXL.mem dev handler") Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://patch.msgid.link/20260114182055.46029-12-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22PCI/AER: Update is_internal_error() to be non-static is_aer_internal_error()Terry Bowman
The AER driver includes significant logic for handling CXL protocol errors. The AER driver will be updated in the future to separate the AER and CXL logic. Rename the is_internal_error() function to is_aer_internal_error() as it gives a more precise indication of the purpose. Make is_aer_internal_error() non-static to allow for the 2 different CXL topology error model implementations (RCH and VH) to share this helper. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Link: https://patch.msgid.link/20260114182055.46029-11-terry.bowman@amd.com Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22PCI/AER: Export pci_aer_unmask_internal_errors()Terry Bowman
Internal PCIe errors are not enabled by default during initialization because their behavior is too device-specific and there is no standard way to reason about them. However, for CXL an internal error is the standard mechanism for conveying CXL protocol errors. Export pci_aer_unmask_internal_errors() for CXL, but make it clear that they are only meant for CXL and the status quo for leaving them masked for PCIe in general remains. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Link: https://patch.msgid.link/20260114182055.46029-10-terry.bowman@amd.com Co-developed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22PCI/AER: Replace PCIEAER_CXL symbol with CXL_RASDan Williams
One of the primary reasons for the CXL driver to exist is to perform error handling. If both PCIEAER and CXL are enabled then light up CXL error handling as well. Now that all RAS handling is moved under the CXL_RAS symbol, drop the previous PCIEAER_CXL symbol. Reviewed-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Link: https://patch.msgid.link/20260114182055.46029-14-terry.bowman@amd.com Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22PCI: Replace cxl_error_is_native() with pcie_aer_is_native()Terry Bowman
The AER driver includes a CXL support function cxl_error_is_native(). This function adds no additional value from pcie_aer_is_native(). Simplify the codebase by removing cxl_error_is_native() and replace occurrences of cxl_error_is_native() with pcie_aer_is_native(). Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20260114182055.46029-7-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22PCI: Introduce pcie_is_cxl()Terry Bowman
CXL is a protocol that runs on top of PCIe electricals. Its error model also runs on top of the PCIe AER error model by standardizing "internal" errors as "CXL" errors. Linux has historically ignored internal errors. CXL protocol error handling is then a task of enhancing the PCIe AER core to understand that PCIe ports (upstream and downstream) and endpoints may throw internal errors that represent standard CXL protocol errors. The proposed method to make that determination is to teach 'struct pci_dev' to cache when its link has trained the CXL.mem and/or CXL.cache protocols and then treat all internal errors as CXL errors. A design goal is to not burden the PCIe AER core with CXL knowledge beyond just enough to forward error notifications to the CXL RAS core. The forwarded notification looks up a 'struct cxl_port' or 'struct cxl_dport' companion device to the PCI device. Introduce set_pcie_cxl() with logic checking for CXL.mem or CXL.cache status in the CXL Flex Bus DVSEC status register. The CXL Flex Bus DVSEC presence is used because it is required for all the CXL PCIe devices.[1] [1] CXL 3.1 Spec, 8.1.1 PCIe Designated Vendor-Specific Extended Capability (DVSEC) ID Assignment, Table 8-2 Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Alejandro Lucero <alucerop@amd.com> Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://patch.msgid.link/20260114182055.46029-4-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2026-01-22PCI/PM: Prevent runtime suspend until devices are fully initializedBrian Norris
Previously, it was possible for a PCI device to be runtime-suspended before it was fully initialized. When that happened, the suspend process could save invalid device state, for example, before BAR assignment. Restoring the invalid state during resume may leave the device non-functional. Prevent runtime suspend for PCI devices until they are fully initialized by deferring pm_runtime_enable(). More details on how exactly this may occur: 1. PCI device is created by pci_scan_slot() or similar 2. As part of pci_scan_slot(), pci_pm_init() puts the device in D0 and prevents runtime suspend prevented via pm_runtime_forbid() 3. pci_device_add() adds the underlying 'struct device' via device_add(), which means user space can allow runtime suspend, e.g., echo auto > /sys/bus/pci/devices/.../power/control 4. PCI device receives BAR configuration (pci_assign_unassigned_bus_resources(), etc.) 5. pci_bus_add_device() applies final fixups, saves device state, and tries to attach a driver The device may potentially be suspended between #3 and #5, so this is racy with user space (udev or similar). Many PCI devices are enumerated at subsys_initcall time and so will not race with user space, but devices created later by hotplug or modular pwrctrl or host controller drivers are susceptible to this race. More runtime PM details at the first Link: below. Link: https://lore.kernel.org/all/0e35a4e1-894a-47c1-9528-fc5ffbafd9e2@samsung.com/ Signed-off-by: Brian Norris <briannorris@chromium.org> [bhelgaas: update comments per https://lore.kernel.org/r/CAJZ5v0iBNOmMtqfqEbrYyuK2u+2J2+zZ-iQd1FvyCPjdvU2TJg@mail.gmail.com] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260122094815.v5.1.I60a53c170a8596661883bd2b4ef475155c7aa72b@changeid
2026-01-22PCI: Prepare to protect against concurrent isolated cpuset changeFrederic Weisbecker
HK_TYPE_DOMAIN will soon integrate cpuset isolated partitions and therefore be made modifiable at runtime. Synchronize against the cpumask update using RCU. The RCU locked section includes both the housekeeping CPU target election for the PCI probe work and the work enqueue. This way the housekeeping update side will simply need to flush the pending related works after updating the housekeeping mask in order to make sure that no PCI work ever executes on an isolated CPU. This part will be handled in a subsequent patch. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-pci@vger.kernel.org Cc: Marco Crivellari <marco.crivellari@suse.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Waiman Long <longman@redhat.com>