linux-kernel - Re: [PATCH v3 2/3] cxl/edac: Fix wrong dpa checking for PPR operation

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Message-ID: <aG3I9ooPm0eJnMPn@aschofie-mobl2.lan>
Date: Tue, 8 Jul 2025 18:42:14 -0700
From: Alison Schofield <alison.schofield@...el.com>
To: Li Ming <ming.li@...omail.com>
CC: <dave@...olabs.net>, <jonathan.cameron@...wei.com>,
	<dave.jiang@...el.com>, <vishal.l.verma@...el.com>, <ira.weiny@...el.com>,
	<dan.j.williams@...el.com>, <shiju.jose@...wei.com>,
	<andriy.shevchenko@...ux.intel.com>, <linux-cxl@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 2/3] cxl/edac: Fix wrong dpa checking for PPR operation

On Tue, Jul 08, 2025 at 01:15:35PM +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.
> 

If it needs a fixes tag, doesn't it also need a user visible impact
statement? I get that the PPR won't happen. What does that look like
to the user? Is there a user level error message we can add to the
commit log?

With that, you can add:
Reviewed-by: Alison Schofield <alison.schofield@...el.com>



> Fixes: be9b359e056a ("cxl/edac: Add CXL memory device soft PPR control feature")
> Signed-off-by: Li Ming <ming.li@...omail.com>
> Tested-by: Shiju Jose <shiju.jose@...wei.com>
> Reviewed-by: Shiju Jose <shiju.jose@...wei.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;
>  
>  	return cxl_mem_perform_ppr(cxl_ppr_ctx);
> -- 
> 2.34.1
>