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Jonathan Cameron 721992163e cxl/regs: Fix size of CXL Capability Header Register
[ Upstream commit 74b0fe8040 ]

In CXL 2.0, 8.2.5.1 CXL Capability Header Register: this register
is given as 32 bits.

8.2.3 which covers the CXL 2.0 Component registers, including the
CXL Capability Header Register states that access restrictions
specified in Section 8.2.2 apply.

8.2.2 includes:
* A 32 bit register shall be accessed as a 4 Byte quantity.
...
If these rules are not followed, the behavior is undefined.

Discovered during review of CXL QEMU emulation. Alex Bennée pointed
out there was a comment saying that 4 byte registers must be read
with a 4 byte read, but 8 byte reads were being emulated.

https://lore.kernel.org/qemu-devel/87bkzyd3c7.fsf@linaro.org/

Fixing that, led to this code failing. Whilst a given hardware
implementation 'might' work with an 8 byte read, it should not be relied
upon. The QEMU emulation v5 will return 0 and log the wrong access width.

The code moved, so one fixes tag for where this will directly apply and
also a reference to the earlier introduction of the code for backports.

Fixes: 0f06157e01 ("cxl/core: Move register mapping infrastructure")
Fixes: 08422378c4 ("cxl/pci: Add HDM decoder capabilities")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Ben Widawsky <ben.widawsky@intel.com>
Link: https://lore.kernel.org/r/20220201153437.2873-1-Jonathan.Cameron@huawei.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:23:30 +02:00
arch powerpc/perf: Don't use perf_hw_context for trace IMC PMU 2022-04-08 14:23:27 +02:00
block block: don't delete queue kobject before its children 2022-04-08 14:23:07 +02:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto crypto: authenc - Fix sleep in atomic context in decrypt_tail 2022-04-08 14:23:05 +02:00
Documentation vsprintf: Fix %pK with kptr_restrict == 0 2022-04-08 14:23:18 +02:00
drivers cxl/regs: Fix size of CXL Capability Header Register 2022-04-08 14:23:30 +02:00
fs f2fs: fix compressed file start atomic write may cause data corruption 2022-04-08 14:23:11 +02:00
include drm/edid: Split deep color modes between RGB and YUV444 2022-04-08 14:23:25 +02:00
init init: make unknown command line param message clearer 2021-11-18 19:17:11 +01:00
ipc ipc/sem: do not sleep with a spin lock held 2022-02-08 18:34:03 +01:00
kernel livepatch: Fix build failure on 32 bits processors 2022-04-08 14:23:29 +02:00
lib vsprintf: Fix %pK with kptr_restrict == 0 2022-04-08 14:23:18 +02:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm mm/kmemleak: reset tag when compare object pointer 2022-04-08 14:22:56 +02:00
net mac80211: limit bandwidth in HE capabilities 2022-04-08 14:23:28 +02:00
samples samples/landlock: Fix path_list memory leak 2022-04-08 14:22:59 +02:00
scripts scripts/dtc: Call pkg-config POSIXly correct 2022-04-08 14:23:29 +02:00
security KEYS: trusted: Avoid calling null function trusted_key_exit 2022-04-08 14:23:09 +02:00
sound ASoC: amd: Fix reference to PCM buffer address 2022-04-08 14:23:22 +02:00
tools libbpf: Fix signedness bug in btf_dump_array_data() 2022-04-08 14:23:30 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt KVM: Fix lockdep false negative during host resume 2022-03-16 14:23:40 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +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 .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
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 MAINTAINERS: adjust file entry for of_net.c after movement 2022-03-08 19:12:53 +01:00
Makefile Linux 5.15.32 2022-03-28 09:58:46 +02:00
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.