On Mon, Aug 05, 2024 at 10:13:38PM +0200, John Paul Adrian Glaubitz wrote:
> On Mon, 2024-08-05 at 12:21 -0700, Paul E. McKenney wrote:
> > Use the new cmpxchg_emu_u8() to emulate one-byte cmpxchg() on sh.
> >
> > [ paulmck: Drop two-byte support per Arnd Bergmann feedback. ]
> > [ paulmck: Apply feedback from Naresh Kamboju. ]
> > [ Apply Geert Uytterhoeven feedback. ]
> >
> > Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
> > Cc: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
> > Cc: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
> > Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> > Cc: Arnd Bergmann <arnd@xxxxxxxx>
> > Cc: <linux-sh@xxxxxxxxxxxxxxx>
> > ---
> > arch/sh/Kconfig | 1 +
> > arch/sh/include/asm/cmpxchg.h | 3 +++
> > 2 files changed, 4 insertions(+)
> >
> > diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
> > index 1aa3c4a0c5b27..e9103998cca91 100644
> > --- a/arch/sh/Kconfig
> > +++ b/arch/sh/Kconfig
> > @@ -14,6 +14,7 @@ config SUPERH
> > select ARCH_HIBERNATION_POSSIBLE if MMU
> > select ARCH_MIGHT_HAVE_PC_PARPORT
> > select ARCH_WANT_IPC_PARSE_VERSION
> > + select ARCH_NEED_CMPXCHG_1_EMU
> > select CPU_NO_EFFICIENT_FFS
> > select DMA_DECLARE_COHERENT
> > select GENERIC_ATOMIC64
> > diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
> > index 5d617b3ef78f7..1e5dc5ccf7bf5 100644
> > --- a/arch/sh/include/asm/cmpxchg.h
> > +++ b/arch/sh/include/asm/cmpxchg.h
> > @@ -9,6 +9,7 @@
> >
> > #include <linux/compiler.h>
> > #include <linux/types.h>
> > +#include <linux/cmpxchg-emu.h>
> >
> > #if defined(CONFIG_GUSA_RB)
> > #include <asm/cmpxchg-grb.h>
> > @@ -56,6 +57,8 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
> > unsigned long new, int size)
> > {
> > switch (size) {
> > + case 1:
> > + return cmpxchg_emu_u8(ptr, old, new);
> > case 4:
> > return __cmpxchg_u32(ptr, old, new);
> > }
>
> Acked-by: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Thank you very much! I will apply this on my next rebase.
Thanx, Paul
