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Hans de Goede a2b36ffbf5 x86/PCI: Revert "x86/PCI: Clip only host bridge windows for E820 regions"
This reverts commit 4c5e242d3e.

Prior to 4c5e242d3e ("x86/PCI: Clip only host bridge windows for E820
regions"), E820 regions did not affect PCI host bridge windows.  We only
looked at E820 regions and avoided them when allocating new MMIO space.
If firmware PCI bridge window and BAR assignments used E820 regions, we
left them alone.

After 4c5e242d3e, we removed E820 regions from the PCI host bridge
windows before looking at BARs, so firmware assignments in E820 regions
looked like errors, and we moved things around to fit in the space left
(if any) after removing the E820 regions.  This unnecessary BAR
reassignment broke several machines.

Guilherme reported that Steam Deck fails to boot after 4c5e242d3e.  We
clipped the window that contained most 32-bit BARs:

  BIOS-e820: [mem 0x00000000a0000000-0x00000000a00fffff] reserved
  acpi PNP0A08:00: clipped [mem 0x80000000-0xf7ffffff window] to [mem 0xa0100000-0xf7ffffff window] for e820 entry [mem 0xa0000000-0xa00fffff]

which forced us to reassign all those BARs, for example, this NVMe BAR:

  pci 0000:00:01.2: PCI bridge to [bus 01]
  pci 0000:00:01.2:   bridge window [mem 0x80600000-0x806fffff]
  pci 0000:01:00.0: BAR 0: [mem 0x80600000-0x80603fff 64bit]
  pci 0000:00:01.2: can't claim window [mem 0x80600000-0x806fffff]: no compatible bridge window
  pci 0000:01:00.0: can't claim BAR 0 [mem 0x80600000-0x80603fff 64bit]: no compatible bridge window

  pci 0000:00:01.2: bridge window: assigned [mem 0xa0100000-0xa01fffff]
  pci 0000:01:00.0: BAR 0: assigned [mem 0xa0100000-0xa0103fff 64bit]

All the reassignments were successful, so the devices should have been
functional at the new addresses, but some were not.

Andy reported a similar failure on an Intel MID platform.  Benjamin
reported a similar failure on a VMWare Fusion VM.

Note: this is not a clean revert; this revert keeps the later change to
make the clipping dependent on a new pci_use_e820 bool, moving the checking
of this bool to arch_remove_reservations().

[bhelgaas: commit log, add more reporters and testers]
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=216109
Reported-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Reported-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reported-by: Benjamin Coddington <bcodding@redhat.com>
Reported-by: Jongman Heo <jongman.heo@gmail.com>
Fixes: 4c5e242d3e ("x86/PCI: Clip only host bridge windows for E820 regions")
Link: https://lore.kernel.org/r/20220612144325.85366-1-hdegoede@redhat.com
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2022-06-17 14:24:14 -05:00
arch x86/PCI: Revert "x86/PCI: Clip only host bridge windows for E820 regions" 2022-06-17 14:24:14 -05:00
block for-5.19/drivers-2022-06-02 2022-06-03 10:25:56 -07:00
certs Kbuild updates for v5.19 2022-05-26 12:09:50 -07:00
crypto This update includes the following changes: 2022-05-27 18:06:49 -07:00
Documentation A single featurelet for delay accounting. Delayed a bit 2022-06-05 16:58:27 -07:00
drivers fix for breakage in #work.fd this window 2022-06-05 17:14:03 -07:00
fs fix for breakage in #work.fd this window 2022-06-05 17:14:03 -07:00
include A single featurelet for delay accounting. Delayed a bit 2022-06-05 16:58:27 -07:00
init This set of changes updates init and user mode helper tasks to be 2022-06-03 16:03:05 -07:00
ipc These changes update the ipc sysctls so that they are fundamentally 2022-06-03 15:54:57 -07:00
kernel A single featurelet for delay accounting. Delayed a bit 2022-06-05 16:58:27 -07:00
lib Bitmap patches for 5.19-rc1 2022-06-04 14:04:27 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm Hot fixes for 5.19-rc1. 2022-06-05 17:05:38 -07:00
net bluetooth: don't use bitmaps for random flag accesses 2022-06-05 16:28:41 -07:00
samples drm for 5.19-rc1 2022-05-25 16:18:27 -07:00
scripts A set of objtool fixes: 2022-06-05 09:45:27 -07:00
security Cleanups (and one fix) around struct mount handling. 2022-06-04 19:00:05 -07:00
sound USB / Thunderbolt changes for 5.19-rc1 2022-06-03 11:17:49 -07:00
tools A single featurelet for delay accounting. Delayed a bit 2022-06-05 16:58:27 -07:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt VFIO updates for v5.19-rc1 2022-06-01 13:49:15 -07:00
.clang-format clang-format: Fix space after for_each macros 2022-05-20 19:27:16 +02:00
.cocciconfig
.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 kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap Hot fixes for 5.19-rc1. 2022-06-05 17:05:38 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
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 Hot fixes for 5.19-rc1. 2022-06-05 17:05:38 -07:00
Makefile Linux 5.19-rc1 2022-06-05 17:18:54 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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Please read the Documentation/process/changes.rst file, as it contains the
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