Re: [PATCH 1/1] cxl/acpi: Fix using extra xormaps for address translation

[Dave Jiang]

On 1/15/26 6:16 AM, Li Ming wrote:
> CXL r3.1 Table 9-22 defines a fixed number of XOR maps for interleave
> arithmetic based on the number of interleave ways, as reflected by
> hbiw_to_nr_maps[].
> 
> The current implementation applies all XOR maps during address
> translation, but it should use the spec-defined number of XOR maps
> derived from the number of interleave ways.

Can you add what is the current impact without applying the fix pls?

DJ

> 
> Fixes: 3b2fedcd75e3 ("cxl: Restore XOR'd position bits during address translation")
> Signed-off-by: Li Ming <ming.li@xxxxxxxxxxxx>
> ---
>  drivers/cxl/acpi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
> index 77ac940e3013..5f84d01e7d39 100644
> --- a/drivers/cxl/acpi.c
> +++ b/drivers/cxl/acpi.c
> @@ -61,7 +61,7 @@ u64 cxl_do_xormap_calc(struct cxl_cxims_data *cximsd, u64 addr, int hbiw)
>  	 * bits results in val==0, if odd the XOR result is val==1.
>  	 */
>  
> -	for (int i = 0; i < cximsd->nr_maps; i++) {
> +	for (int i = 0; i < nr_maps_to_apply; i++) {
>  		if (!cximsd->xormaps[i])
>  			continue;
>  		pos = __ffs(cximsd->xormaps[i]);