From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Ira Weiny <ira.weiny@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>,
Shiju Jose <shiju.jose@huawei.com>,
Dan Carpenter <dan.carpenter@linaro.org>,
"Yazen Ghannam" <yazen.ghannam@amd.com>,
Davidlohr Bueso <dave@stgolabs.net>,
Alison Schofield <alison.schofield@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>,
Ard Biesheuvel <ardb@kernel.org>, <linux-efi@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <linux-cxl@vger.kernel.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
"Tony Luck" <tony.luck@intel.com>, Borislav Petkov <bp@alien8.de>
Subject: Re: [PATCH v4 1/2] acpi/ghes: Process CXL Component Events
Date: Mon, 29 Apr 2024 17:24:18 +0100 [thread overview]
Message-ID: <20240429172418.0000534c@Huawei.com> (raw)
In-Reply-To: <20240426-cxl-cper3-v4-1-58076cce1624@intel.com>
On Fri, 26 Apr 2024 20:34:00 -0700
Ira Weiny <ira.weiny@intel.com> 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>
Totally trivial comment inline. Maybe Dave can tweak whilst applying...
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> diff --git a/include/linux/cxl-event.h b/include/linux/cxl-event.h
> index 03fa6d50d46f..a0067c49e2ca 100644
> --- a/include/linux/cxl-event.h
> +++ b/include/linux/cxl-event.h
> @@ -3,6 +3,8 @@
> #ifndef _LINUX_CXL_EVENT_H
> #define _LINUX_CXL_EVENT_H
>
> +#include <linux/workqueue_types.h>
> +
> /*
> * Common Event Record Format
> * CXL rev 3.0 section 8.2.9.2.1; Table 8-42
> @@ -140,4 +142,29 @@ struct cxl_cper_event_rec {
> union cxl_event event;
> } __packed;
>
> +struct cxl_cper_work_data {
> + enum cxl_event_type event_type;
> + struct cxl_cper_event_rec rec;
> +};
> +
> +#ifdef CONFIG_ACPI_APEI_GHES
> +int cxl_cper_register_work(struct work_struct *work);
> +int cxl_cper_unregister_work(struct work_struct *work);
> +int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd);
> +#else
> +static inline int cxl_cper_register_work(struct work_struct *work);
> +{
> + return 0;
> +}
> +
> +static inline int cxl_cper_unregister_work(struct work_struct *work);
> +{
> + return 0;
> +}
Trivial note of the day: Inconsistent spacing - add a blank line here.
> +static inline int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd)
> +{
> + return 0;
> +}
> +#endif
> +
> #endif /* _LINUX_CXL_EVENT_H */
>
next prev parent reply other threads:[~2024-04-29 16:24 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-27 3:33 [PATCH v4 0/2] efi/cxl-cper: Report CXL CPER events through tracing Ira Weiny
2024-04-27 3:34 ` [PATCH v4 1/2] acpi/ghes: Process CXL Component Events Ira Weiny
2024-04-29 16:24 ` Jonathan Cameron [this message]
2024-04-29 16:47 ` Ira Weiny
2024-04-30 18:32 ` Tony Luck
2024-04-30 18:50 ` Ira Weiny
2024-04-30 19:33 ` Luck, Tony
2024-05-01 6:36 ` Smita Koralahalli
2024-05-01 17:26 ` Ira Weiny
2024-04-27 3:34 ` [PATCH v4 2/2] cxl/pci: Process CPER events Ira Weiny
2024-04-29 16:25 ` Jonathan Cameron
2024-05-01 6:38 ` Smita Koralahalli
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