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Robert Richter f05fd10d13 cxl/pci: Add RCH downstream port AER register discovery
Restricted CXL host (RCH) downstream port AER information is not currently
logged while in the error state. One problem preventing the error logging
is the AER and RAS registers are not accessible. The CXL driver requires
changes to find RCH downstream port AER and RAS registers for purpose of
error logging.

RCH downstream ports are not enumerated during a PCI bus scan and are
instead discovered using system firmware, ACPI in this case.[1] The
downstream port is implemented as a Root Complex Register Block (RCRB).
The RCRB is a 4k memory block containing PCIe registers based on the PCIe
root port.[2] The RCRB includes AER extended capability registers used for
reporting errors. Note, the RCH's AER Capability is located in the RCRB
memory space instead of PCI configuration space, thus its register access
is different. Existing kernel PCIe AER functions can not be used to manage
the downstream port AER capabilities and RAS registers because the port was
not enumerated during PCI scan and the registers are not PCI config
accessible.

Discover RCH downstream port AER extended capability registers. Use MMIO
accesses to search for extended AER capability in RCRB register space.

[1] CXL 3.0 Spec, 9.11.2 - System Firmware View of CXL 1.1 Hierarchy
[2] CXL 3.0 Spec, 8.2.1.1 - RCH Downstream Port RCRB

Co-developed-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20231018171713.1883517-12-rrichter@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27 20:13:38 -07:00
arch Fourteen hotfixes, eleven of which are cc:stable. The remainder pertain 2023-10-01 13:33:25 -07:00
block block: fix kernel-doc for disk_force_media_change() 2023-09-26 00:43:34 -06:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: sm2 - Fix crash caused by uninitialized context 2023-09-20 13:10:10 +08:00
Documentation Kbuild fixes for v6.6 (2nd) 2023-10-01 13:48:46 -07:00
drivers cxl/pci: Add RCH downstream port AER register discovery 2023-10-27 20:13:38 -07:00
fs Fourteen hotfixes, eleven of which are cc:stable. The remainder pertain 2023-10-01 13:33:25 -07:00
include Kbuild fixes for v6.6 (2nd) 2023-10-01 13:48:46 -07:00
init workqueue: Changes for v6.6 2023-09-01 16:06:32 -07:00
io_uring io_uring/fs: remove sqe->rw_flags checking from LINKAT 2023-09-29 03:07:09 -06:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel Fourteen hotfixes, eleven of which are cc:stable. The remainder pertain 2023-10-01 13:33:25 -07:00
lib maple_tree: add MAS_UNDERFLOW and MAS_OVERFLOW states 2023-09-29 17:20:46 -07:00
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mm Fourteen hotfixes, eleven of which are cc:stable. The remainder pertain 2023-10-01 13:33:25 -07:00
net Networking fixes for 6.6-rc2, including fixes from netfilter and bpf 2023-09-21 11:28:16 -07:00
rust Documentation work keeps chugging along; stuff for 6.6 includes: 2023-08-30 20:05:42 -07:00
samples VFIO updates for v6.6-rc1 2023-08-30 20:36:01 -07:00
scripts kbuild: remove stale code for 'source' symlink in packaging scripts 2023-10-01 23:06:06 +09:00
security selinux: fix handling of empty opts in selinux_fs_context_submount() 2023-09-12 17:31:08 -04:00
sound ASoC: Fixes for v6.6 2023-09-20 15:02:16 +02:00
tools cxl/pci: Remove Component Register base address from struct cxl_dev_state 2023-10-27 20:13:37 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
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.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS ARM: SoC fixes for 6.6 2023-09-30 18:41:37 -07:00
Makefile Linux 6.6-rc4 2023-10-01 14:15:13 -07:00
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.