3bd6b8271e
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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.