On 10.01.20 19:40, Claudio Imbrenda wrote:
> Add a wrapper for the SET PREFIX and STORE PREFIX instructions, and
> use it instead of using inline assembly.
>
> Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
> Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx>
> ---
> lib/s390x/asm/arch_def.h | 13 +++++++++++++
> s390x/intercept.c | 23 ++++++++---------------
> 2 files changed, 21 insertions(+), 15 deletions(-)
>
> diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
> index 1a5e3c6..15a4d49 100644
> --- a/lib/s390x/asm/arch_def.h
> +++ b/lib/s390x/asm/arch_def.h
> @@ -284,4 +284,17 @@ static inline int servc(uint32_t command, unsigned long sccb)
> return cc;
> }
>
> +static inline void set_prefix(uint32_t new_prefix)
> +{
> + asm volatile(" spx %0" : : "Q" (new_prefix) : "memory");
> +}
> +
> +static inline uint32_t get_prefix(void)
> +{
> + uint32_t current_prefix;
> +
> + asm volatile(" stpx %0" : "=Q" (current_prefix));
> + return current_prefix;
> +}
> +
> #endif
> diff --git a/s390x/intercept.c b/s390x/intercept.c
> index 3696e33..cd96121 100644
> --- a/s390x/intercept.c
> +++ b/s390x/intercept.c
> @@ -26,13 +26,10 @@ static void test_stpx(void)
> uint32_t new_prefix = (uint32_t)(intptr_t)pagebuf;
>
> /* Can we successfully change the prefix? */
> - asm volatile (
> - " stpx %0\n"
> - " spx %2\n"
> - " stpx %1\n"
> - " spx %0\n"
> - : "+Q"(old_prefix), "+Q"(tst_prefix)
> - : "Q"(new_prefix));
> + old_prefix = get_prefix();
> + set_prefix(new_prefix);
> + tst_prefix = get_prefix();
> + set_prefix(old_prefix);
> report(old_prefix == 0 && tst_prefix == new_prefix, "store prefix");
>
> expect_pgm_int();
> @@ -63,14 +60,10 @@ static void test_spx(void)
> * some facility bits there ... at least some of them should be
> * set in our buffer afterwards.
> */
> - asm volatile (
> - " stpx %0\n"
> - " spx %1\n"
> - " stfl 0\n"
> - " spx %0\n"
> - : "+Q"(old_prefix)
> - : "Q"(new_prefix)
> - : "memory");
> + old_prefix = get_prefix();
> + set_prefix(new_prefix);
> + asm volatile(" stfl 0" : : : "memory");
> + set_prefix(old_prefix);
> report(pagebuf[GEN_LC_STFL] != 0, "stfl to new prefix");
>
> expect_pgm_int();
>
Besides the comments from Janosch, looks good to me.
--
Thanks,
David / dhildenb
