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author | Punit Agrawal <punitagrawal@gmail.com> | 2021-06-15 02:04:57 +0300 |
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committer | Bjorn Helgaas <bhelgaas@google.com> | 2021-06-18 18:31:37 +0300 |
commit | 3bd6b8271ee660803c5694cc25420c499c5c0592 (patch) | |
tree | 9407ce8c4a95b9b13b4201b9c4de4165c5b58e4c /drivers/pci | |
parent | 6efb943b8616ec53a5e444193dccf1af9ad627b5 (diff) | |
download | linux-3bd6b8271ee660803c5694cc25420c499c5c0592.tar.xz |
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 <bhelgaas@google.com>
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 <alexandru.elisei@arm.com>
Reported-by: Qu Wenruo <wqu@suse.com>
Tested-by: Alexandru Elisei <alexandru.elisei@arm.com>
Tested-by: Domenico Andreoli <domenico.andreoli@linux.com>
Signed-off-by: Punit Agrawal <punitagrawal@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Diffstat (limited to 'drivers/pci')
-rw-r--r-- | drivers/pci/of.c | 2 |
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", 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); |