6.17-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ilpo Järvinen ilpo.jarvinen@linux.intel.com
commit 31af09b3eaf3603870ce9fd5a7b6c8693129c4cf upstream.
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... 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.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pci/setup-bus.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-)
--- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -28,6 +28,10 @@ #include <linux/acpi.h> #include "pci.h"
+#define PCI_RES_TYPE_MASK \ + (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH |\ + IORESOURCE_MEM_64) + unsigned int pci_flags; EXPORT_SYMBOL_GPL(pci_flags);
@@ -384,13 +388,19 @@ static bool pci_need_to_release(unsigned }
/* Return: @true if assignment of a required resource failed. */ -static bool pci_required_resource_failed(struct list_head *fail_head) +static bool pci_required_resource_failed(struct list_head *fail_head, + unsigned long type) { struct pci_dev_resource *fail_res;
+ type &= PCI_RES_TYPE_MASK; + list_for_each_entry(fail_res, fail_head, list) { int idx = pci_resource_num(fail_res->dev, fail_res->res);
+ if (type && (fail_res->flags & PCI_RES_TYPE_MASK) != type) + continue; + if (!pci_resource_is_optional(fail_res->dev, idx)) return true; } @@ -504,7 +514,7 @@ assign: }
/* Without realloc_head and only optional fails, nothing more to do. */ - if (!pci_required_resource_failed(&local_fail_head) && + if (!pci_required_resource_failed(&local_fail_head, 0) && list_empty(realloc_head)) { list_for_each_entry(save_res, &save_head, list) { struct resource *res = save_res->res; @@ -1707,10 +1717,6 @@ static void __pci_bridge_assign_resource } }
-#define PCI_RES_TYPE_MASK \ - (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH |\ - IORESOURCE_MEM_64) - static void pci_bridge_release_resources(struct pci_bus *bus, unsigned long type) { @@ -2449,8 +2455,12 @@ int pci_reassign_bridge_resources(struct free_list(&added);
if (!list_empty(&failed)) { - ret = -ENOSPC; - goto cleanup; + if (pci_required_resource_failed(&failed, type)) { + ret = -ENOSPC; + goto cleanup; + } + /* Only resources with unrelated types failed (again) */ + free_list(&failed); }
list_for_each_entry(dev_res, &saved, list) {