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authorPaul E. McKenney <paulmck@kernel.org>2024-03-27 15:28:04 -0700
committerPaul E. McKenney <paulmck@kernel.org>2024-09-13 07:10:38 -0700
commite799bef0d9c85b963938d8f31806a898385a5b09 (patch)
tree76231fcc340ff3b3be611ee142b098c5490eed1a /arch/xtensa
parentc81a748edefd098ea21dd35d4bba03f69412fc26 (diff)
xtensa: Emulate one-byte cmpxchg
Use the new cmpxchg_emu_u8() to emulate one-byte cmpxchg() on xtensa. [ paulmck: Apply kernel test robot feedback. ] [ paulmck: Drop two-byte support per Arnd Bergmann feedback. ] [ Apply Geert Uytterhoeven feedback. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Yujie Liu <yujie.liu@intel.com> Cc: Andi Shyti <andi.shyti@linux.intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Diffstat (limited to 'arch/xtensa')
-rw-r--r--arch/xtensa/Kconfig1
-rw-r--r--arch/xtensa/include/asm/cmpxchg.h2
2 files changed, 3 insertions, 0 deletions
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index f200a4ec044e..d3db28f2f811 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -14,6 +14,7 @@ config XTENSA
select ARCH_HAS_DMA_SET_UNCACHED if MMU
select ARCH_HAS_STRNCPY_FROM_USER if !KASAN
select ARCH_HAS_STRNLEN_USER
+ select ARCH_NEED_CMPXCHG_1_EMU
select ARCH_USE_MEMTEST
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS
diff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h
index 675a11ea8de7..95e33a913962 100644
--- a/arch/xtensa/include/asm/cmpxchg.h
+++ b/arch/xtensa/include/asm/cmpxchg.h
@@ -15,6 +15,7 @@
#include <linux/bits.h>
#include <linux/stringify.h>
+#include <linux/cmpxchg-emu.h>
/*
* cmpxchg
@@ -74,6 +75,7 @@ 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);
default: __cmpxchg_called_with_bad_pointer();
return old;