From: Punit Agrawal Date: Mon, 14 Jun 2021 23:04:57 +0000 (+0900) Subject: PCI: of: Clear 64-bit flag for non-prefetchable memory below 4GB X-Git-Tag: v5.15~954^2~8 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=3bd6b8271ee660803c5694cc25420c499c5c0592;p=mirror_ubuntu-kernels.git 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: https://lore.kernel.org/r/20210614230457.752811-1-punitagrawal@gmail.com Reported-at: https://lore.kernel.org/lkml/7a1e2ebc-f7d8-8431-d844-41a9c36a8911@arm.com/ Reported-at: https://lore.kernel.org/lkml/YMyTUv7Jsd89PGci@m4/T/#u 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 --- 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", dev_node); *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);