Re: [PATCH v3 6/7] acpi/ghes, cper: Recognize and cache CXL Protocol errors

[Koralahalli Channabasappa, Smita]

Hi Ira,

On 12/2/2024 10:41 AM, Ira Weiny wrote:
> Smita Koralahalli wrote:
> > Add support in GHES to detect and process CXL CPER Protocol errors, as
> > defined in UEFI v2.10, section N.2.13.
> >
> > Define struct cxl_cper_prot_err_work_data to cache CXL protocol error
> > information, including RAS capabilities and severity, for further
> > handling.
> >
> > These cached CXL CPER records will later be processed by workqueues
> > within the CXL subsystem.
> >
> > Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@xxxxxxx>
> > ---
> >   drivers/acpi/apei/ghes.c | 52 ++++++++++++++++++++++++++++++++++++++++
> >   include/cxl/event.h      |  6 +++++
> >   2 files changed, 58 insertions(+)
> >
> > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> > index 62ffe6eb5503..6cd9d5375d7c 100644
> > --- a/drivers/acpi/apei/ghes.c
> > +++ b/drivers/acpi/apei/ghes.c
> > @@ -676,6 +676,54 @@ static void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
> >   	schedule_work(&entry->work);
> >   }
> >   
> > +static void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err,
> > +				   int severity)
> > +{
> > +	struct cxl_cper_prot_err_work_data wd;
> > +	u8 *dvsec_start, *cap_start;
> > +
> > +	if (!(prot_err->valid_bits & PROT_ERR_VALID_AGENT_ADDRESS)) {
> > +		pr_err_ratelimited("CXL CPER invalid agent type\n");
> > +		return;
> > +	}
> > +
> > +	if (!(prot_err->valid_bits & PROT_ERR_VALID_ERROR_LOG)) {
> > +		pr_err_ratelimited("CXL CPER invalid protocol error log\n");
> > +		return;
> > +	}
> > +
> > +	if (prot_err->err_len != sizeof(struct cxl_ras_capability_regs)) {
> > +		pr_err_ratelimited("CXL CPER invalid RAS Cap size (%u)\n",
> > +				   prot_err->err_len);
> > +		return;
> > +	}
> > +
> > +	if (!(prot_err->valid_bits & PROT_ERR_VALID_SERIAL_NUMBER))
> > +		pr_warn(FW_WARN "CXL CPER no device serial number\n");
> > +
> > +	switch (prot_err->agent_type) {
> > +	case RCD:
> > +	case DEVICE:
> > +	case LD:
> > +	case FMLD:
> > +	case RP:
> > +	case DSP:
> > +	case USP:
> > +		memcpy(&wd.prot_err, prot_err, sizeof(wd.prot_err));
> > +
> > +		dvsec_start = (u8 *)(prot_err + 1);
> > +		cap_start = dvsec_start + prot_err->dvsec_len;
> > +
> > +		wd.ras_cap = *(struct cxl_ras_capability_regs *)cap_start;
> Why not memcpy()?

Thanks for pointing out. Yes, I will change to memcpy() in next 
revision. I think

memcpy() may suit more better here due to consistency and as well addressing

alignment concerns.


Thanks

Smita

> Ira
>
> [snip]