Messages in this thread | | | Date | Tue, 6 Apr 2021 18:57:53 +0800 | From | Gao Xiang <> | Subject | Re: [PATCH] parisc: avoid a warning on u8 cast for cmpxchg on u8 pointers |
| |
On Tue, Apr 06, 2021 at 12:08:55PM +0200, Helge Deller wrote: > On 4/6/21 6:59 AM, Gao Xiang wrote: > > From: Gao Xiang <hsiangkao@redhat.com> > > > > commit b344d6a83d01 ("parisc: add support for cmpxchg on u8 pointers") > > can generate a sparse warningi ("cast truncates bits from constant > > value"), which has been reported several times [1] [2] [3]. > > > > The original code worked as expected, but anyway, let silence such > > sparse warning as what others did [4]. > > > > [1] https://lore.kernel.org/r/202104061220.nRMBwCXw-lkp@intel.com > > [2] https://lore.kernel.org/r/202012291914.T5Agcn99-lkp@intel.com > > [3] https://lore.kernel.org/r/202008210829.KVwn7Xeh%25lkp@intel.com > > [4] https://lore.kernel.org/r/20210315131512.133720-2-jacopo+renesas@jmondi.org > > Cc: Liam Beguin <liambeguin@gmail.com> > > Cc: Helge Deller <deller@gmx.de> > > Signed-off-by: Gao Xiang <hsiangkao@redhat.com> > > applied to the parisc for-next git tree. > (I fixed up the typo above too)
Thanks all! :)
Thanks, Gao Xiang
> > Thanks! > Helge > > > --- > > arch/parisc/include/asm/cmpxchg.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/parisc/include/asm/cmpxchg.h b/arch/parisc/include/asm/cmpxchg.h > > index cf5ee9b0b393..84ee232278a6 100644 > > --- a/arch/parisc/include/asm/cmpxchg.h > > +++ b/arch/parisc/include/asm/cmpxchg.h > > @@ -72,7 +72,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size) > > #endif > > case 4: return __cmpxchg_u32((unsigned int *)ptr, > > (unsigned int)old, (unsigned int)new_); > > - case 1: return __cmpxchg_u8((u8 *)ptr, (u8)old, (u8)new_); > > + case 1: return __cmpxchg_u8((u8 *)ptr, old & 0xff, new_ & 0xff); > > } > > __cmpxchg_called_with_bad_pointer(); > > return old; > > >
| |