Re: [kvm-unit-tests PATCH 4/8] lib: s390x: Start using bitops instead of magic constants

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

On Fri, 13 Aug 2021 07:36:11 +0000
Janosch Frank <frankja@linux.ibm.com> wrote:

> TEID data is specified in the Principles of Operation as bits so it
> makes more sens to test the bits instead of anding the mask.
> 
> We need to set -Wno-address-of-packed-member since for test bit we
> take an address of a struct lowcore member.

and s390x has no alignment requirements

> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

> ---
>  lib/s390x/interrupt.c | 5 +++--
>  s390x/Makefile        | 1 +
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
> index 1248bceb..e05c212e 100644
> --- a/lib/s390x/interrupt.c
> +++ b/lib/s390x/interrupt.c
> @@ -8,6 +8,7 @@
>   *  David Hildenbrand <david@redhat.com>
>   */
>  #include <libcflat.h>
> +#include <bitops.h>
>  #include <asm/barrier.h>
>  #include <sclp.h>
>  #include <interrupt.h>
> @@ -77,8 +78,8 @@ static void fixup_pgm_int(struct stack_frame_int
> *stack) break;
>  	case PGM_INT_CODE_PROTECTION:
>  		/* Handling for iep.c test case. */
> -		if (lc->trans_exc_id & 0x80UL && lc->trans_exc_id &
> 0x04UL &&
> -		    !(lc->trans_exc_id & 0x08UL))
> +		if (test_bit_inv(56, &lc->trans_exc_id) &&
> test_bit_inv(61, &lc->trans_exc_id) &&
> +		    !test_bit_inv(60, &lc->trans_exc_id))
>  			/*
>  			 * We branched to the instruction that caused
>  			 * the exception so we can use the return
> diff --git a/s390x/Makefile b/s390x/Makefile
> index ef8041a6..d260b336 100644
> --- a/s390x/Makefile
> +++ b/s390x/Makefile
> @@ -45,6 +45,7 @@ CFLAGS += -O2
>  CFLAGS += -march=zEC12
>  CFLAGS += -mbackchain
>  CFLAGS += -fno-delete-null-pointer-checks
> +CFLAGS += -Wno-address-of-packed-member
>  LDFLAGS += -nostdlib -Wl,--build-id=none
>  
>  # We want to keep intermediate files