From a34d74877c66ce484ad586d806002ceaedd58657 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Thu, 3 Apr 2025 12:31:37 +0300 Subject: [PATCH] PCI: Restore assigned resources fully after release MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit PCI resource fitting code in __assign_resources_sorted() runs in multiple steps. A resource that was successfully assigned may have to be released before the next step attempts assignment again. The assign+release cycle is destructive to a start-aligned struct resource (bridge window or IOV resource) because the start field is overwritten with the real address when the resource got assigned. One symptom: pci 0002:00:00.0: bridge window [mem size 0x00100000]: can't assign; bogus alignment Properly restore the resource after releasing it. The start, end, and flags fields must be stored into the related struct pci_dev_resource in order to be able to restore the resource to its original state. Fixes: 96336ec70264 ("PCI: Perform reset_resource() and build fail list in sync") Reported-by: Guenter Roeck Closes: https://lore.kernel.org/r/01eb7d40-f5b5-4ec5-b390-a5c042c30aff@roeck-us.net/ Reported-by: Nicolas Frattaroli Closes: https://lore.kernel.org/r/3578030.5fSG56mABF@workhorse Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Tested-by: Nicolas Frattaroli Tested-by: Guenter Roeck Tested-by: Ondrej Jirman Link: https://patch.msgid.link/20250403093137.1481-1-ilpo.jarvinen@linux.intel.com --- drivers/pci/setup-bus.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 54d6f4fa3ce1..e994c546422c 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -187,6 +187,9 @@ static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head) panic("%s: kzalloc() failed!\n", __func__); tmp->res = r; tmp->dev = dev; + tmp->start = r->start; + tmp->end = r->end; + tmp->flags = r->flags; /* Fallback is smallest one or list is empty */ n = head; @@ -545,6 +548,7 @@ static void __assign_resources_sorted(struct list_head *head, pci_dbg(dev, "%s %pR: releasing\n", res_name, res); release_resource(res); + restore_dev_resource(dev_res); } /* Restore start/end/flags from saved list */ list_for_each_entry(save_res, &save_head, list)