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 send
> these events to the OS 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 only difference is the UUID is
> passed via the Section Type as a GUID and not included as part of the
> record data.
>
> Add EFI support to detect CXL CPER records and call a notifier chain
> with the record data blobs.
>
> Note that the format of a GUID and UUID are not the same. Therefore the
> Section Type GUID must be converted to a UUID prior to being used by the
> CXL code. Make that conversion and send it along to those registered.
>
> Not-Yet-Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
>
> ---
> RFC comments:
> I'm still not sure if the 'CXL Component Event Log' portion of the CPER
> record includes the UUID from the CXL Common Event Record Format.
>
> The 2.10 version of the UEFI spec says:
>
> "For the CXL Component Event Log: Refer to the Common Event Record field
> (Offset 16) of the Events Record Format for each CXL component."
>
> This implies that the first 16 bytes (the UUID) is not included. It
> would be nice if the UUID were included there as a copy of what would
> normally be in the CXL event log. If so the Section Type GUID could be
> used solely to match for a CXL record and ignored in the CXL code.
>
> For now convert the GUID to UUID and pass to the notifier users.
>
> Smita, Another idea I had was to add your cper_print_comp_event()
> function to the dump here to capture that CPER specific data in the EFI
> log.
> ---
> drivers/firmware/efi/cper.c | 16 ++++++++++++++
> drivers/firmware/efi/cper_cxl.c | 39 ++++++++++++++++++++++++++++++++
> drivers/firmware/efi/cper_cxl.h | 29 ++++++++++++++++++++++++
> include/linux/efi.h | 49 +++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 133 insertions(+)
>
> diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
> index 35c37f667781..af2c59f5e21d 100644
> --- a/drivers/firmware/efi/cper.c
> +++ b/drivers/firmware/efi/cper.c
> @@ -607,6 +607,22 @@ cper_estatus_print_section(const char *pfx, struct acpi_hest_generic_data *gdata
> cper_print_prot_err(newpfx, prot_err);
> else
> goto err_section_too_small;
> + } else if (guid_equal(sec_type, &gen_media_event_guid) ||
> + guid_equal(sec_type, &dram_event_guid) ||
> + guid_equal(sec_type, &mem_mod_event_guid)) {
> + struct cper_cxl_event_rec *rec = acpi_hest_get_payload(gdata);
> +
Smita,
Dan and I were discussing the processing of these GUIDs vs the UUIDs in the
trace prints offline.
Here we could separate out the comparisons and use a token for the events
rather than passing the guid through to be converted into a uuid...
> + printk("%ssection type: CXL Event\n", newpfx);
> +
> + if (rec->hdr.length <= sizeof(rec->hdr))
> + goto err_section_too_small;
> +
> + if (rec->hdr.length > sizeof(*rec)) {
> + pr_err(FW_WARN "error section length is too big\n");
> + return;
> + }
> +
> + cper_post_cxl_event(newpfx, sec_type, rec);
> } else {
> const void *err = acpi_hest_get_payload(gdata);
>
> diff --git a/drivers/firmware/efi/cper_cxl.c b/drivers/firmware/efi/cper_cxl.c
> index a55771b99a97..9b1a64ed542e 100644
> --- a/drivers/firmware/efi/cper_cxl.c
> +++ b/drivers/firmware/efi/cper_cxl.c
> @@ -187,3 +187,42 @@ void cper_print_prot_err(const char *pfx, const struct cper_sec_prot_err *prot_e
> sizeof(cxl_ras->header_log), 0);
> }
> }
> +
> +/* CXL CPER notifier chain */
> +static BLOCKING_NOTIFIER_HEAD(cxl_cper_chain_head);
> +
> +void cper_post_cxl_event(const char *pfx, guid_t *guid, struct cper_cxl_event_rec *rec)
> +{
> + struct cxl_cper_notifier_data nd = {
> + .rec = rec,
> + };
> + char guid_str[UUID_STRING_LEN + 1]; /* + trailing NULL */
> +
> + if (!(rec->hdr.validation_bits & CPER_CXL_COMP_EVENT_LOG_VALID)) {
> + pr_err(FW_WARN "cxl event no Compoent Event Log present\n");
> + return;
> + }
> +
> + snprintf(guid_str, UUID_STRING_LEN + 1, "%pU", guid);
> + if (uuid_parse(guid_str, &nd.uuid))
> + pr_err(FW_WARN "cxl event uuid conversion failed\n");
> +
> + pr_info("%s cxl event guid %pU, uuid %pU\n", pfx, guid, &nd.uuid);
> +
> + if (blocking_notifier_call_chain(&cxl_cper_chain_head, 0, (void *)&nd)
> + == NOTIFY_BAD)
> + pr_err(FW_WARN "cxl event notifier chain failed\n");
> +}
> +
