path: root/drivers/pci/of.c
diff options
authorPunit Agrawal <>2021-06-15 08:04:57 +0900
committerBjorn Helgaas <>2021-06-18 10:31:37 -0500
commit3bd6b8271ee660803c5694cc25420c499c5c0592 (patch)
tree9407ce8c4a95b9b13b4201b9c4de4165c5b58e4c /drivers/pci/of.c
parent6efb943b8616ec53a5e444193dccf1af9ad627b5 (diff)
PCI: of: Clear 64-bit flag for non-prefetchable memory below 4GB
Alexandru and Qu reported this resource allocation failure on ROCKPro64 v2 and ROCK Pi 4B, both based on the RK3399: pci_bus 0000:00: root bus resource [mem 0xfa000000-0xfbdfffff 64bit] pci 0000:00:00.0: PCI bridge to [bus 01] pci 0000:00:00.0: BAR 14: no space for [mem size 0x00100000] pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x00003fff 64bit] "BAR 14" is the PCI bridge's 32-bit non-prefetchable window, and our PCI allocation code isn't smart enough to allocate it in a host bridge window marked as 64-bit, even though this should work fine. A DT host bridge description includes the windows from the CPU address space to the PCI bus space. On a few architectures (microblaze, powerpc, sparc), the DT may also describe PCI devices themselves, including their BARs. Before 9d57e61bf723 ("of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses"), of_bus_pci_get_flags() ignored the fact that some DT addresses described 64-bit windows and BARs. That was a problem because the virtio virtual NIC has a 32-bit BAR and a 64-bit BAR, and the driver couldn't distinguish them. 9d57e61bf723 set IORESOURCE_MEM_64 for those 64-bit DT ranges, which fixed the virtio driver. But it also set IORESOURCE_MEM_64 for host bridge windows, which exposed the fact that the PCI allocator isn't smart enough to put 32-bit resources in those 64-bit windows. Clear IORESOURCE_MEM_64 from host bridge windows since we don't need that information. Suggested-by: Bjorn Helgaas <> Fixes: 9d57e61bf723 ("of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses") Link: Reported-at: Reported-at: Reported-by: Alexandru Elisei <> Reported-by: Qu Wenruo <> Tested-by: Alexandru Elisei <> Tested-by: Domenico Andreoli <> Signed-off-by: Punit Agrawal <> Signed-off-by: Bjorn Helgaas <> Reviewed-by: Rob Herring <> Acked-by: Ard Biesheuvel <>
Diffstat (limited to 'drivers/pci/of.c')
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index da5b414d585a..4866612dfdb2 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -346,6 +346,8 @@ static int devm_of_pci_get_host_bridge_resources(struct device *dev,
dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n",
*io_base = range.cpu_addr;
+ } else if (resource_type(res) == IORESOURCE_MEM) {
+ res->flags &= ~IORESOURCE_MEM_64;
pci_add_resource_offset(resources, res, res->start - range.pci_addr);