Re: [kvm-unit-tests PATCH v6 08/10] s390x: define wfi: wait for interrupt

Janosch Frank
2020-04-27T12:59:24Z

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On 4/24/20 12:45 PM, Pierre Morel wrote:
> wfi(irq_mask) allows the programm to wait for an interrupt.

s/programm/program/

> The interrupt handler is in charge to remove the WAIT bit
> when it finished handling interrupt.

...finished handling the interrupt.

>
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
> lib/s390x/asm/arch_def.h | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
> index a0d2362..e04866c 100644
> --- a/lib/s390x/asm/arch_def.h
> +++ b/lib/s390x/asm/arch_def.h
> @@ -13,6 +13,7 @@
> #define PSW_MASK_EXT 0x0100000000000000UL
> #define PSW_MASK_DAT 0x0400000000000000UL
> #define PSW_MASK_SHORT_PSW 0x0008000000000000UL
> +#define PSW_MASK_WAIT 0x0002000000000000UL
> #define PSW_MASK_PSTATE 0x0001000000000000UL
> #define PSW_MASK_BA 0x0000000080000000UL
> #define PSW_MASK_EA 0x0000000100000000UL
> @@ -254,6 +255,16 @@ static inline void load_psw_mask(uint64_t mask)
> : "+r" (tmp) : "a" (&psw) : "memory", "cc" );
> }
>
> +static inline void wfi(uint64_t irq_mask)

enabled_wait()

> +{
> + uint64_t psw_mask;

You can directly initialize this variable.

> +
> + psw_mask = extract_psw_mask();
> + load_psw_mask(psw_mask | irq_mask | PSW_MASK_WAIT);

Maybe add a comment here:

/*
* After being woken and having processed the interrupt, let's restore
the PSW mask.
*/

> + load_psw_mask(psw_mask);
> +}
> +
> +
> static inline void enter_pstate(void)
> {
> uint64_t mask;
>

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