* [PATCH RFC cmpxchg 5/8] sh: Emulate one-byte and two-byte cmpxchg
[not found] <31c82dcc-e203-48a9-aadd-f2fcd57d94c1@paulmck-laptop>
@ 2024-04-01 21:39 ` Paul E. McKenney
0 siblings, 0 replies; only message in thread
From: Paul E. McKenney @ 2024-04-01 21:39 UTC (permalink / raw)
To: linux-kernel
Cc: kernel-team, Paul E. McKenney, Andi Shyti, Palmer Dabbelt,
Masami Hiramatsu, linux-sh
Use the new cmpxchg_emu_u8() and cmpxchg_emu_u16() to emulate one-byte
and two-byte cmpxchg() on sh.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: <linux-sh@vger.kernel.org>
---
arch/sh/Kconfig | 1 +
arch/sh/include/asm/cmpxchg.h | 4 ++++
2 files changed, 5 insertions(+)
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 2ad3e29f0ebec..43a121c6ca0f3 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -16,6 +16,7 @@ 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_2_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..18233cc14419e 100644
--- a/arch/sh/include/asm/cmpxchg.h
+++ b/arch/sh/include/asm/cmpxchg.h
@@ -56,6 +56,10 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
unsigned long new, int size)
{
switch (size) {
+ case 1:
+ return cmpxchg_emu_u8((volatile u8 *)ptr, old, new);
+ case 2:
+ return cmpxchg_emu_u16((volatile u16 *)ptr, old, new);
case 4:
return __cmpxchg_u32(ptr, old, new);
}
--
2.40.1
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