Re: [PATCH v2 2/3] cxl/edac: Fix wrong dpa checking for PPR operation

[Alison Schofield <alison.schofield@intel.com>]

On Wed, Jul 02, 2025 at 03:20:07PM +0800, Li Ming wrote:
> DPA 0 is considered invalid in cxl_do_ppr(), but per Table 8-143. "Get
> Partition Info Output Payload" in CXL r3.2 section 8.2.10.9.2.1 "Get
> Partition Info(Opcode 4100h)", it mentions that DPA 0 is a valid address
> of a CXL device. So the correct implementation should be checking if the
> DPA is in the DPA range of the CXL device rather than checking if the
> DPA is equal to 0.
> 
> Fixes: be9b359e056a ("cxl/edac: Add CXL memory device soft PPR control feature")
> Signed-off-by: Li Ming <ming.li@zohomail.com>
> ---
>  drivers/cxl/core/edac.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/core/edac.c b/drivers/cxl/core/edac.c
> index 623aaa4439c4..1cf65b1538b9 100644
> --- a/drivers/cxl/core/edac.c
> +++ b/drivers/cxl/core/edac.c
> @@ -1923,8 +1923,11 @@ static int cxl_ppr_set_nibble_mask(struct device *dev, void *drv_data,
>  static int cxl_do_ppr(struct device *dev, void *drv_data, u32 val)
>  {
>  	struct cxl_ppr_context *cxl_ppr_ctx = drv_data;
> +	struct cxl_memdev *cxlmd = cxl_ppr_ctx->cxlmd;
> +	struct cxl_dev_state *cxlds = cxlmd->cxlds;
>  
> -	if (!cxl_ppr_ctx->dpa || val != EDAC_DO_MEM_REPAIR)
> +	if (!resource_contains_addr(&cxlds->dpa_res, cxl_ppr_ctx->dpa) ||
> +	    val != EDAC_DO_MEM_REPAIR)
>  		return -EINVAL;

Hi Ming,

I think this one needs a user visible impact statement.

I'm hoping the broader helper gets accepted. That may be the ioport.h
addition, or maybe we end up with a CXL special helper.

However, if this patch is aiming to go upstream as a FIX in a 6.16 rc,
then we are probably better off fixing the check inline right here, and
then you follow on with the other 2 patches to be considered for the
next merge window.

Please share that impact and suggest whether it can wait for next merge
window.

-- Alison


>  
>  	return cxl_mem_perform_ppr(cxl_ppr_ctx);
> -- 
> 2.34.1
>