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authorYunhong Jiang <yunhong.jiang@linux.intel.com>2017-03-08 23:13:28 -0800
committerYunhong Jiang <yunhong.jiang@linux.intel.com>2017-03-08 23:36:15 -0800
commit52f993b8e89487ec9ee15a7fb4979e0f09a45b27 (patch)
treed65304486afe0bea4a311c783c0d72791c8c0aa2 /kernel/arch/arm64/include/asm/spinlock.h
parentc189ccac5702322ed843fe17057035b7222a59b6 (diff)
Upgrade to 4.4.50-rt62
The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it to 4.4.50-rt62. The command to achieve it is: a) Clone a git repo from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git b) Get the diff between this two changesets: git diff 640eca2901f3435e616157b11379d3223a44b391 705619beeea1b0b48219a683fd1a901a86fdaf5e where the two commits are: [yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only 640eca2901f3435e616157b11379d3223a44b391 640eca2901f3 v4.4.6-rt14 localversion-rt [yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only 705619beeea1b0b48219a683fd1a901a86fdaf5e 705619beeea1 Linux 4.4.50-rt62 localversion-rt c) One patch has been backported thus revert the patch before applying. filterdiff -p1 -x scripts/package/Makefile ~/tmp/v4.4.6-rt14-4.4.50-rt62.diff |patch -p1 --dry-run Upstream status: backport Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01 Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>
Diffstat (limited to 'kernel/arch/arm64/include/asm/spinlock.h')
-rw-r--r--kernel/arch/arm64/include/asm/spinlock.h10
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/arch/arm64/include/asm/spinlock.h b/kernel/arch/arm64/include/asm/spinlock.h
index c85e96d17..499e8de33 100644
--- a/kernel/arch/arm64/include/asm/spinlock.h
+++ b/kernel/arch/arm64/include/asm/spinlock.h
@@ -312,4 +312,14 @@ static inline int arch_read_trylock(arch_rwlock_t *rw)
#define arch_read_relax(lock) cpu_relax()
#define arch_write_relax(lock) cpu_relax()
+/*
+ * Accesses appearing in program order before a spin_lock() operation
+ * can be reordered with accesses inside the critical section, by virtue
+ * of arch_spin_lock being constructed using acquire semantics.
+ *
+ * In cases where this is problematic (e.g. try_to_wake_up), an
+ * smp_mb__before_spinlock() can restore the required ordering.
+ */
+#define smp_mb__before_spinlock() smp_mb()
+
#endif /* __ASM_SPINLOCK_H */