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Punit Agrawal 3bd6b8271e 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 9d57e61bf7 ("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.

9d57e61bf7 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: 9d57e61bf7 ("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>
2021-06-18 10:31:37 -05:00
Documentation A set of scheduler updates: 2021-05-09 13:14:34 -07:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
arch Handle power-gating of AMD IOMMU perf counters properly when they are used. 2021-05-09 13:00:26 -07:00
block block-5.13-2021-05-09 2021-05-09 13:25:14 -07:00
certs Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
crypto for-5.13/drivers-2021-04-27 2021-04-28 14:39:37 -07:00
drivers PCI: of: Clear 64-bit flag for non-prefetchable memory below 4GB 2021-06-18 10:31:37 -05:00
fs 3 small SMB3 chmultichannel related changesets (also for stable) 2021-05-09 13:19:29 -07:00
include block-5.13-2021-05-09 2021-05-09 13:25:14 -07:00
init Merge branch 'akpm' (patches from Andrew) 2021-05-07 00:34:51 -07:00
ipc ipc/sem.c: spelling fix 2021-05-07 00:26:34 -07:00
kernel A set of scheduler updates: 2021-05-09 13:14:34 -07:00
lib Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
mm mm: fix typos in comments 2021-05-07 00:26:35 -07:00
net Networking fixes for 5.13-rc1, including fixes from bpf, can 2021-05-08 08:31:46 -07:00
samples Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
scripts Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
security Simple code cleanup 2021-05-05 12:08:06 -07:00
sound sound fixes for 5.13-rc1 2021-05-07 11:40:18 -07:00
tools Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
usr .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
virt KVM: Boost vCPU candidate in user mode which is delivering interrupt 2021-04-21 12:20:03 -04:00
.clang-format cxl for 5.12 2021-02-24 09:38:36 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap It's been a relatively busy cycle in docsland, though more than usually 2021-04-26 13:22:43 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: move Murali Karicheri to credits 2021-04-29 15:47:30 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Networking fixes for 5.13-rc1, including fixes from bpf, can 2021-05-08 08:31:46 -07:00
Makefile Linux 5.13-rc1 2021-05-09 14:17:44 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

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.