@@ -18,12 +18,12 @@ __xchg_u32(volatile void *p, unsigned long val)
unsigned long prev;
__asm__ __volatile__(
- PPC_RELEASE_BARRIER
+ PPC_ATOMIC_ENTRY_BARRIER
"1: lwarx %0,0,%2 \n"
PPC405_ERR77(0,%2)
" stwcx. %3,0,%2 \n\
bne- 1b"
- PPC_ACQUIRE_BARRIER
+ PPC_ATOMIC_EXIT_BARRIER
: "=&r" (prev), "+m" (*(volatile unsigned int *)p)
: "r" (p), "r" (val)
: "cc", "memory");
@@ -61,12 +61,12 @@ __xchg_u64(volatile void *p, unsigned long val)
unsigned long prev;
__asm__ __volatile__(
- PPC_RELEASE_BARRIER
+ PPC_ATOMIC_ENTRY_BARRIER
"1: ldarx %0,0,%2 \n"
PPC405_ERR77(0,%2)
" stdcx. %3,0,%2 \n\
bne- 1b"
- PPC_ACQUIRE_BARRIER
+ PPC_ATOMIC_EXIT_BARRIER
: "=&r" (prev), "+m" (*(volatile unsigned long *)p)
: "r" (p), "r" (val)
: "cc", "memory");
@@ -152,14 +152,14 @@ __cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new)
unsigned int prev;
__asm__ __volatile__ (
- PPC_RELEASE_BARRIER
+ PPC_ATOMIC_ENTRY_BARRIER
"1: lwarx %0,0,%2 # __cmpxchg_u32\n\
cmpw 0,%0,%3\n\
bne- 2f\n"
PPC405_ERR77(0,%2)
" stwcx. %4,0,%2\n\
bne- 1b"
- PPC_ACQUIRE_BARRIER
+ PPC_ATOMIC_EXIT_BARRIER
"\n\
2:"
: "=&r" (prev), "+m" (*p)
@@ -198,13 +198,13 @@ __cmpxchg_u64(volatile unsigned long *p, unsigned long old, unsigned long new)
unsigned long prev;
__asm__ __volatile__ (
- PPC_RELEASE_BARRIER
+ PPC_ATOMIC_ENTRY_BARRIER
"1: ldarx %0,0,%2 # __cmpxchg_u64\n\
cmpd 0,%0,%3\n\
bne- 2f\n\
stdcx. %4,0,%2\n\
bne- 1b"
- PPC_ACQUIRE_BARRIER
+ PPC_ATOMIC_EXIT_BARRIER
"\n\
2:"
: "=&r" (prev), "+m" (*p)
This is a note to let you know that I have just added a patch titled powerpc: Make {cmp}xchg* and their atomic_ versions fully ordered to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue This patch is scheduled to be released in version 3.13.11-ckt34. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.13.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 8d7383708d2ca4b8ffc76df82fd0b5fb9b4e64a7 Mon Sep 17 00:00:00 2001 From: Boqun Feng <boqun.feng@gmail.com> Date: Mon, 2 Nov 2015 09:30:32 +0800 Subject: powerpc: Make {cmp}xchg* and their atomic_ versions fully ordered commit 81d7a3294de7e9828310bbf986a67246b13fa01e upstream. According to memory-barriers.txt, xchg*, cmpxchg* and their atomic_ versions all need to be fully ordered, however they are now just RELEASE+ACQUIRE, which are not fully ordered. So also replace PPC_RELEASE_BARRIER and PPC_ACQUIRE_BARRIER with PPC_ATOMIC_ENTRY_BARRIER and PPC_ATOMIC_EXIT_BARRIER in __{cmp,}xchg_{u32,u64} respectively to guarantee fully ordered semantics of atomic{,64}_{cmp,}xchg() and {cmp,}xchg(), as a complement of commit b97021f85517 ("powerpc: Fix atomic_xxx_return barrier semantics") This patch depends on patch "powerpc: Make value-returning atomics fully ordered" for PPC_ATOMIC_ENTRY_BARRIER definition. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/powerpc/include/asm/cmpxchg.h | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) -- 1.9.1