Commit 11721c45 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Bjorn Helgaas
Browse files

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: 23b13bc7 ("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: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarAndy 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
parent 8f0b4cce

drivers/pci/probe.c

+2 −4
Original line number Diff line number Diff line
@@ -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;