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Marek Behún 391ca20ea1 Revert "PCI: aardvark: Fix support for PCI_ROM_ADDRESS1 on emulated bridge"
commit 39bd54d43b upstream.

This reverts commit 239edf686c.

239edf686c ("PCI: aardvark: Fix support for PCI_ROM_ADDRESS1 on emulated
bridge") added support for the Type 1 Expansion ROM BAR at config offset
0x38, based on the register being listed in the Marvell Armada A3720 spec.
But the spec doesn't document it at all for RC mode, and there is no ROM in
the SOC, so remove this emulation for now.

The PCI bridge which represents aardvark's PCIe Root Port has an Expansion
ROM Base Address register at offset 0x30, but its meaning is different than
PCI's Expansion ROM BAR register, although the layout is the same.  (This
is why we thought it does the same thing.)

First: there is no ROM (or part of BootROM) in the A3720 SOC dedicated for
PCIe Root Port (or controller in RC mode) containing executable code that
would initialize the Root Port, suitable for execution in bootloader (this
is how Expansion ROM BAR is used on x86).

Second: in A3720 spec the register (address 0xD0070030) is not documented
at all for Root Complex mode, but similar to other BAR registers, it has an
"entangled partner" in register 0xD0075920, which does address translation
for the BAR in 0xD0070030:

  - the BAR register sets the address from the view of PCIe bus

  - the translation register sets the address from the view of the CPU

The other BAR registers also have this entangled partner, and they can be
used to:

  - in RC mode: address-checking on the receive side of the RC (they can
    define address ranges for memory accesses from remote Endpoints to the
    RC)

  - in Endpoint mode: allow the remote CPU to access memory on A3720

The Expansion ROM BAR has only the Endpoint part documented, but from the
similarities we think that it can also be used in RC mode in that way.

So either Expansion ROM BAR has different meaning (if the hypothesis above
is true), or we don't know it's meaning (since it is not documented for RC
mode).

Remove the register from the emulated bridge accessing functions.

[bhelgaas: summarize reason for removal (first paragraph)]
Fixes: 239edf686c ("PCI: aardvark: Fix support for PCI_ROM_ADDRESS1 on emulated bridge")
Link: https://lore.kernel.org/r/20211125160148.26029-3-kabel@kernel.org
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 11:32:42 +01:00
arch KVM: x86: Wait for IPIs to be delivered when handling Hyper-V TLB flush hypercall 2021-12-14 11:32:37 +01:00
block block: fix ioprio_get(IOPRIO_WHO_PGRP) vs setuid(2) 2021-12-14 11:32:40 +01:00
certs certs: Trigger creation of RSA module signing key if it's not an RSA key 2021-09-15 09:50:29 +02:00
crypto crypto: pcrypt - Delay write to padata->info 2021-11-18 14:04:12 +01:00
Documentation netfilter: ipvs: Fix reuse connection if RS weight is 0 2021-12-01 09:19:02 +01:00
drivers Revert "PCI: aardvark: Fix support for PCI_ROM_ADDRESS1 on emulated bridge" 2021-12-14 11:32:42 +01:00
fs tracefs: Set all files to the same group ownership as the mount option 2021-12-14 11:32:40 +01:00
include PM: runtime: Fix pm_runtime_active() kerneldoc comment 2021-12-14 11:32:41 +01:00
init bootconfig: init: Fix memblock leak in xbc_make_cmdline() 2021-11-21 13:46:35 +01:00
ipc shm: extend forced shm destroy to support objects from several IPC nses 2021-12-01 09:19:10 +01:00
kernel wait: add wake_up_pollfree() 2021-12-14 11:32:39 +01:00
lib siphash: use _unaligned version by default 2021-12-08 09:03:23 +01:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm: bdi: initialize bdi_min_ratio when bdi is unregistered 2021-12-14 11:32:37 +01:00
net net/sched: fq_pie: prevent dismantle issue 2021-12-14 11:32:37 +01:00
samples samples/kretprobes: Fix return value if register_kretprobe() failed 2021-11-18 14:04:11 +01:00
scripts gcc-plugins: fix gcc 11 indigestion with plugins... 2021-12-14 11:32:33 +01:00
security selinux: fix NULL-pointer dereference when hashtab allocation fails 2021-11-26 10:39:21 +01:00
sound ASoC: codecs: wcd934x: return correct value from mixer put 2021-12-14 11:32:41 +01:00
tools bpf: Fix the off-by-two error in range markings 2021-12-14 11:32:36 +01:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: Disallow user memslot with size that exceeds "unsigned long" 2021-12-08 09:03:21 +01:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.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: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +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 f2fs: move ioctl interface definitions to separated file 2021-05-19 10:13:00 +02:00
Makefile Linux 5.10.84 2021-12-08 09:03:30 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.