Re: [PATCH rc] s390: Use the correct count for __iowrite64_copy()

[Heiko Carstens <hca@linux.ibm.com>]

On Fri, Feb 16, 2024 at 08:48:14PM -0400, Jason Gunthorpe wrote:
> The signature for __iowrite64_copy() requires the number of 64 bit
> quantities, not bytes. Multiple by 8 to get to a byte length before
> invoking zpci_memcpy_toio()
> 
> Fixes: 87bc359b9822 ("s390/pci: speed up __iowrite64_copy by using pci store block insn")
> Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  arch/s390/pci/pci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
> index 676ac74026a82b..52a44e353796c0 100644
> --- a/arch/s390/pci/pci.c
> +++ b/arch/s390/pci/pci.c
> @@ -252,7 +252,7 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
>  /* combine single writes by using store-block insn */
>  void __iowrite64_copy(void __iomem *to, const void *from, size_t count)
>  {
> -       zpci_memcpy_toio(to, from, count);
> +	zpci_memcpy_toio(to, from, count * 8);
>  }

Odd, this bug is 11 years old, and there was never any bug report.
Is this never called, or how is this possible?

Niklas, would you happen to have an idea?