lkml.org 
[lkml]   [2024]   [Apr]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v4 1/2] acpi/ghes: Process CXL Component Events
From
Date
On 4/26/2024 8:34 PM, Ira Weiny wrote:
> BIOS can configure memory devices as firmware first. This will send CXL
> events to the firmware instead of the OS. The firmware can then inform
> the OS of these events via UEFI.
>
> UEFI v2.10 section N.2.14 defines a Common Platform Error Record (CPER)
> format for CXL Component Events. The format is mostly the same as the
> CXL Common Event Record Format. The difference lies in the use of a
> GUID as the CPER Section Type which matches the UUID defined in CXL 3.1
> Table 8-43.
>
> Currently a configuration such as this will trace a non standard event
> in the log omitting useful details of the event. In addition the CXL
> sub-system contains additional region and HPA information useful to the
> user.[0]
>
> The CXL code is required to be called from process context as it needs
> to take a device lock. The GHES code may be in interrupt context. This
> complicated the use of a callback. Dan Williams suggested the use of
> work items as an atomic way of switching between the callback execution
> and a default handler.[1]
>
> The use of a kfifo simplifies queue processing by providing lock free
> fifo operations. cxl_cper_kfifo_get() allows easier management of the
> kfifo between the ghes and cxl modules.
>
> CXL 3.1 Table 8-127 requires a device to have a queue depth of 1 for
> each of the four event logs. A combined queue depth of 32 is chosen to
> provide room for 8 entries of each log type.
>
> Add GHES support to detect CXL CPER records. Add the ability for the
> CXL sub-system to register a work queue to process the events.
>
> This patch adds back the functionality which was removed to fix the
> report by Dan Carpenter[2].
>
> Cc: Ard Biesheuvel <ardb@kernel.org>
> Cc: Rafael J. Wysocki <rafael@kernel.org>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
> Suggested-by: Dan Williams <dan.j.williams@intel.com>
> Link: http://lore.kernel.org/r/cover.1711598777.git.alison.schofield@intel.com [0]
> Link: http://lore.kernel.org/r/65d111eb87115_6c745294ac@dwillia2-xfh.jf.intel.com.notmuch [1]
> Link: http://lore.kernel.org/r/b963c490-2c13-4b79-bbe7-34c6568423c7@moroto.mountain [2]
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> ---

Sorry, I couldn't get a chance to follow up with all revisions. But
tested this and it looks good to me.

Tested-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>

\
 
 \ /
  Last update: 2024-05-27 18:11    [W:0.641 / U:0.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site