[PATCH 6/6 v6] ACPI: extlog: Trace CPER CXL Protocol Error Section

[Fabio M. De Francesco]

On Tuesday, October 28, 2025 4:06:09 PM Central European Standard Time Jonathan Cameron wrote:
> On Thu, 23 Oct 2025 14:25:41 +0200
> "Fabio M. De Francesco" <fabio.m.de.francesco at linux.intel.com> wrote:
> 
> > When Firmware First is enabled, BIOS handles errors first and then it makes
> > them available to the kernel via the Common Platform Error Record (CPER)
> > sections (UEFI 2.10 Appendix N). Linux parses the CPER sections via one of
> > two similar paths, either ELOG or GHES. The errors managed by ELOG are
> > signaled to the BIOS by the I/O Machine Check Architecture (I/O MCA).
> > 
> > Currently, ELOG and GHES show some inconsistencies in how they report to
> > userspace via trace events.
> > 
> > Therefore, make the two mentioned paths act similarly by tracing the CPER
> > CXL Protocol Error Section (UEFI v2.10, Appendix N.2.13).
> > 
> > Cc: Dan Williams <dan.j.williams at intel.com>
> > Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy at linux.intel.com>
> > Signed-off-by: Fabio M. De Francesco <fabio.m.de.francesco at linux.intel.com>
> 
> Just one small question.   With that addressed, 
> Reviewed-by: Jonathan Cameron <jonathan.cameron at huawei.com>
> 
> > diff --git a/drivers/cxl/core/ras.c b/drivers/cxl/core/ras.c
> > index 2731ba3a0799..3f527b0c6509 100644
> > --- a/drivers/cxl/core/ras.c
> > +++ b/drivers/cxl/core/ras.c
> > @@ -105,6 +105,12 @@ static void cxl_cper_handle_prot_err(struct cxl_cper_prot_err_work_data *data)
> >  		cxl_cper_trace_uncorr_prot_err(cxlmd, data->ras_cap);
> >  }
> >  
> > +void cxl_cper_ras_handle_prot_err(struct cxl_cper_prot_err_work_data *wd)
> 
> Why do we need this wrapper?  The name is a bit more general, so if you
> do need it, then why not instead just rename cxl_cper_handle_prot_err()
> 
Actually, on a second thought I believe that we don't need either this
wrapper or renaming cxl_cper_handle_prot_err(). I'll export the latter
as it is.

Fabio
> > +{
> > +	cxl_cper_handle_prot_err(wd);
> > +}
> > +EXPORT_SYMBOL_GPL(cxl_cper_ras_handle_prot_err);
> > +
> >  static void cxl_cper_prot_err_work_fn(struct work_struct *work)
> >  {
> >  	struct cxl_cper_prot_err_work_data wd;
> > diff --git a/include/cxl/event.h b/include/cxl/event.h
> > index 94081aec597a..a37eef112411 100644
> > --- a/include/cxl/event.h
> > +++ b/include/cxl/event.h
> > @@ -340,4 +340,6 @@ cxl_cper_setup_prot_err_work_data(struct cxl_cper_prot_err_work_data *wd,
> >  }
> >  #endif
> >  
> > +void cxl_cper_ras_handle_prot_err(struct cxl_cper_prot_err_work_data *wd);
> > +
> >  #endif /* _LINUX_CXL_EVENT_H */
> 
>