Re: [PATCH RFC 09/15] arm_mpam: Fix MSC MMIO window size to use resource_size() instead of end - start

[Andre Przywara]

Hi,

On 8/11/26 15:30, Yin Li wrote:
> struct resource uses an inclusive end address, so the correct size is
> end - start + 1. The previous calculation of end - start was off by one,
> resulting in a mapped window one byte smaller than the actual resource.
> Use resource_size() which correctly computes end - start + 1.

Yes, thanks for catching this and making a patch. We found this 
independently during other MPAM work, but no one got around to make a 
patch ;-)

> Signed-off-by: Yin Li <yin.li@xxxxxxxxxxxxxxxx>

Reviewed-by: Andre Przywara <andre.przywara@xxxxxxx>

So this patch is independent from and non-conflicting with the DT work, 
so either Ben or James pick this one directly, or you put those kind of 
fixes first in the series, when you repost.

Cheers,
Andre

> ---
>   drivers/resctrl/mpam_devices.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
> index 1e082fb60e30..5d1854d97371 100644
> --- a/drivers/resctrl/mpam_devices.c
> +++ b/drivers/resctrl/mpam_devices.c
> @@ -2296,7 +2296,7 @@ static struct mpam_msc *do_mpam_msc_drv_probe(struct platform_device *pdev)
>   			dev_err_once(dev, "Failed to map MSC base address\n");
>   			return ERR_CAST(io);
>   		}
> -		msc->mapped_hwpage_sz = msc_res->end - msc_res->start;
> +		msc->mapped_hwpage_sz = resource_size(msc_res);
>   		msc->mapped_hwpage = io;
>   	} else {
>   		return ERR_PTR(-EINVAL);