Re: [PATCH v5 3/3] cxl/edac: Mask DPA flags in the event record cache key

[Li Ming <ming.li@zohomail.com>]

在 2026/11/8 10:20, Jongwon Lee 写道:
> The low bits of the DPA field in General Media and DRAM event records
> are flags. Bit 0 is VOLATILE and bit 1 is NOT_REPAIRABLE. The trace
> events print the DPA with CXL_DPA_MASK applied, while
> cxl_store_rec_gen_media() and cxl_store_rec_dram() use the raw value as
> the xarray key.
>
> User space takes the DPA from the trace event and writes it to the
> mem_repair dpa attribute. If the record has any flag set, xa_load() does
> not find it and the repair fails with -EINVAL.
>
> Use the masked DPA as the key. Records marked NOT_REPAIRABLE are still
> rejected, because the lookup skips them.
>
> Fixes: 0b5ccb0de1e2 ("cxl/edac: Support for finding memory operation attributes from the current boot")
> Signed-off-by: Jongwon Lee <ai@linux.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>

> ---
>   drivers/cxl/core/edac.c | 16 ++++++++++++----
>   1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/cxl/core/edac.c b/drivers/cxl/core/edac.c
> index 42683b7c54..f627c73ff6 100644
> --- a/drivers/cxl/core/edac.c
> +++ b/drivers/cxl/core/edac.c
> @@ -918,6 +918,16 @@ struct cxl_mem_repair_attrbs {
>   	enum cxl_mem_repair_type repair_type;
>   };
>   
> +/*
> + * The low bits of the event record DPA are flags (VOLATILE, NOT_REPAIRABLE).
> + * Records are looked up by the DPA user space writes back, which comes from
> + * the trace event and has the flags masked off, so key them the same way.
> + */
> +static inline unsigned long cxl_rec_dpa(const struct cxl_event_media_hdr *hdr)
> +{
> +	return le64_to_cpu(hdr->phys_addr) & CXL_DPA_MASK;
> +}
> +
>   static inline bool cxl_rec_not_repairable(const struct cxl_event_media_hdr *hdr)
>   {
>   	return le64_to_cpu(hdr->phys_addr) & CXL_DPA_NOT_REPAIRABLE;
> @@ -1131,8 +1141,7 @@ int cxl_store_rec_gen_media(struct cxl_memdev *cxlmd, union cxl_event *evt)
>   		return -ENOMEM;
>   
>   	old_rec = xa_store(&array_rec->rec_gen_media,
> -			   le64_to_cpu(rec->media_hdr.phys_addr), rec,
> -			   GFP_KERNEL);
> +			   cxl_rec_dpa(&rec->media_hdr), rec, GFP_KERNEL);
>   	if (xa_is_err(old_rec)) {
>   		kfree(rec);
>   		return xa_err(old_rec);
> @@ -1161,8 +1170,7 @@ int cxl_store_rec_dram(struct cxl_memdev *cxlmd, union cxl_event *evt)
>   		return -ENOMEM;
>   
>   	old_rec = xa_store(&array_rec->rec_dram,
> -			   le64_to_cpu(rec->media_hdr.phys_addr), rec,
> -			   GFP_KERNEL);
> +			   cxl_rec_dpa(&rec->media_hdr), rec, GFP_KERNEL);
>   	if (xa_is_err(old_rec)) {
>   		kfree(rec);
>   		return xa_err(old_rec);