On Tue, 7 Nov 2017 18:24:33 +0100
Pierre Morel <pmo...@linux.vnet.ibm.com> wrote:
> There are two places where the same endianness conversion
> is done.
> Let's factor this out into a static function.
>
> Signed-off-by: Pierre Morel <pmo...@linux.vnet.ibm.com>
> Reviewed-by: Yi Min Zhao <zyi...@linux.vnet.ibm.com>
> ---
> hw/s390x/s390-pci-inst.c | 58
> ++++++++++++++++++++++++++----------------------
> 1 file changed, 32 insertions(+), 26 deletions(-)
>
> diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
> index 8e088f3..8fcb02d 100644
> --- a/hw/s390x/s390-pci-inst.c
> +++ b/hw/s390x/s390-pci-inst.c
> @@ -314,6 +314,35 @@ out:
> return 0;
> }
>
> +/**
> + * This function swaps the data at ptr according from one
> + * endianness to the other.
> + * valid data in the uint64_t data field.
I'm not sure what that line is supposed to mean?
> + * @ptr: a pointer to a uint64_t data field
> + * @len: the length of the valid data, must be 1,2,4 or 8
> + */
> +static int zpci_endian_swap(uint64_t *ptr, uint8_t len)
> +{
> + uint64_t data = *ptr;
> + switch (len) {
> + case 1:
> + break;
> + case 2:
> + data = bswap16(data);
> + break;
> + case 4:
> + data = bswap32(data);
> + break;
> + case 8:
> + data = bswap64(data);
> + break;
> + default:
> + return -EINVAL;
> + }
> + *ptr = data;
> + return 0;
> +}
> +
I was expecting more code to use a similar pattern, but it seems
surprisingly uncommon.
