On 23.02.2024 08:58, Nicola Vetrini wrote: > On 2024-02-19 16:14, Nicola Vetrini wrote: >> The cache clearing and invalidation helpers in x86 and Arm didn't >> comply with MISRA C Rule 17.7: "The value returned by a function >> having non-void return type shall be used". On Arm they >> were always returning 0, while some in x86 returned -EOPNOTSUPP >> and in common/grant_table the return value is saved. >> >> As a consequence, a common helper arch_grant_cache_flush that returns >> an integer is introduced, so that each architecture can choose whether >> to >> return an error value on certain conditions, and the helpers have >> either >> been changed to return void (on Arm) or deleted entirely (on x86). >> >> Signed-off-by: Julien Grall <[email protected]> >> Signed-off-by: Nicola Vetrini <[email protected]> >> --- >> The original refactor idea came from Julien Grall in [1]; I edited that >> proposal >> to fix build errors. >> >> I did introduce a cast to void for the call to flush_area_local on x86, >> because >> even before this patch the return value of that function wasn't checked >> in all >> but one use in x86/smp.c, and in this context the helper (perhaps >> incidentally) >> ignored the return value of flush_area_local. >> >> [1] >> https://lore.kernel.org/xen-devel/[email protected]/ >> --- >> xen/arch/arm/include/asm/page.h | 33 ++++++++++++++++++----------- >> xen/arch/x86/include/asm/flushtlb.h | 23 ++++++++++---------- >> xen/common/grant_table.c | 9 +------- >> 3 files changed, 34 insertions(+), 31 deletions(-) >> > > I'll put this patch in the backlog at the moment: too many intricacies > while trying to untangle xen/flushtlb from xen/mm.h, and there are > easier cases that can be done faster. If someone is interested I can > post the partial work I've done so far, even though it doesn't > build on x86.
This https://lists.xen.org/archives/html/xen-devel/2024-02/msg01513.html may be of interest to you in the context here. Jan
