[U-Boot] [PATCH v2 07/23] armv8: add simple sdelay implementation

[Simon Glass]

Hi Andre,

On 4 December 2016 at 18:52, Andre Przywara <andre.przywara at arm.com> wrote:
> The sunxi DRAM setup code needs an sdelay() implementation, which
> wasn't defined for armv8 so far.
> Shamelessly copy the armv7 version and adjust it to work in AArch64.
>
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> ---
>  arch/arm/cpu/armv8/cpu.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/arch/arm/cpu/armv8/cpu.c b/arch/arm/cpu/armv8/cpu.c
> index e06c3cc..0366ff4 100644
> --- a/arch/arm/cpu/armv8/cpu.c
> +++ b/arch/arm/cpu/armv8/cpu.c
> @@ -16,6 +16,19 @@
>  #include <asm/system.h>
>  #include <linux/compiler.h>
>
> +/************************************************************

Can we drop the extra stars and use the normal function comment style?

> + * sdelay() - simple spin loop.  Will be constant time as
> + *  its generally used in bypass conditions only.  This
> + *  is necessary until timers are accessible.
> + *
> + *  not inline to increase chances its in cache when called

Should mention the meaning of the parameter and that it cannot be called with 0.

> + *************************************************************/
> +void sdelay(unsigned long loops)
> +{
> +       __asm__ volatile ("1:\n" "subs %0, %0, #1\n"
> +                         "b.ne 1b" : "=r" (loops) : "0"(loops) : "cc");
> +}
> +
>  int cleanup_before_linux(void)
>  {
>         /*
> --
> 2.8.2
>

Regards,
Simon