From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Date: Mon, 8 Dec 2025 14:56:54 +0000 (+0200)
Subject: PCI: Use resource_set_range() that correctly sets ->end
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=11721c45a8266a9d0c9684153d20e37159465f96;p=thirdparty%2Fkernel%2Flinux.git

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

__pci_read_base() sets resource start and end addresses when resource
is larger than 4G but pci_bus_addr_t or resource_size_t are not capable
of representing 64-bit PCI addresses. This creates a problematic
resource that has non-zero flags but the start and end addresses do not
yield to resource size of 0 but 1.

Replace custom resource addresses setup with resource_set_range()
that correctly sets end address as -1 which results in resource_size()
returning 0.

For consistency, also use resource_set_range() in the other branch that
does size based resource setup.

Fixes: 23b13bc76f35 ("PCI: Fail safely if we can't handle BARs larger than 4GB")
Link: https://lore.kernel.org/all/20251207215359.28895-1-ansuelsmth@gmail.com/T/#m990492684913c5a158ff0e5fc90697d8ad95351b
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Cc: stable@vger.kernel.org
Cc: Christian Marangi <ansuelsmth@gmail.com>
Link: https://patch.msgid.link/20251208145654.5294-1-ilpo.jarvinen@linux.intel.com
---

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 41183aed8f5d9..ad5ae05aad3c8 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -287,8 +287,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 		if ((sizeof(pci_bus_addr_t) < 8 || sizeof(resource_size_t) < 8)
 		    && sz64 > 0x100000000ULL) {
 			res->flags |= IORESOURCE_UNSET | IORESOURCE_DISABLED;
-			res->start = 0;
-			res->end = 0;
+			resource_set_range(res, 0, 0);
 			pci_err(dev, "%s: can't handle BAR larger than 4GB (size %#010llx)\n",
 				res_name, (unsigned long long)sz64);
 			goto out;
@@ -297,8 +296,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 		if ((sizeof(pci_bus_addr_t) < 8) && l) {
 			/* Above 32-bit boundary; try to reallocate */
 			res->flags |= IORESOURCE_UNSET;
-			res->start = 0;
-			res->end = sz64 - 1;
+			resource_set_range(res, 0, sz64);
 			pci_info(dev, "%s: can't handle BAR above 4GB (bus address %#010llx)\n",
 				 res_name, (unsigned long long)l64);
 			goto out;