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authorThomas Gleixner <tglx@linutronix.de>2013-07-12 12:34:42 +0200
committerThomas Gleixner <tglx@linutronix.de>2013-07-12 12:34:42 +0200
commitf2006e27396f55276f24434f56e208d86e7f9908 (patch)
tree71896db916d33888b4286f80117d3cac0da40e6d /arch/arm64/include/asm/sync_bitops.h
parente399eb56a6110e13f97e644658648602e2b08de7 (diff)
parent9903883f1dd6e86f286b7bfa6e4b423f98c1cd9e (diff)
Merge branch 'linus' into timers/urgent
Get upstream changes so we can apply fixes against them Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/arm64/include/asm/sync_bitops.h')
-rw-r--r--arch/arm64/include/asm/sync_bitops.h26
1 files changed, 26 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/sync_bitops.h b/arch/arm64/include/asm/sync_bitops.h
new file mode 100644
index 00000000000..8da0bf4f765
--- /dev/null
+++ b/arch/arm64/include/asm/sync_bitops.h
@@ -0,0 +1,26 @@
+#ifndef __ASM_SYNC_BITOPS_H__
+#define __ASM_SYNC_BITOPS_H__
+
+#include <asm/bitops.h>
+#include <asm/cmpxchg.h>
+
+/* sync_bitops functions are equivalent to the SMP implementation of the
+ * original functions, independently from CONFIG_SMP being defined.
+ *
+ * We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But
+ * under Xen you might be communicating with a completely external entity
+ * who might be on another CPU (e.g. two uniprocessor guests communicating
+ * via event channels and grant tables). So we need a variant of the bit
+ * ops which are SMP safe even on a UP kernel.
+ */
+
+#define sync_set_bit(nr, p) set_bit(nr, p)
+#define sync_clear_bit(nr, p) clear_bit(nr, p)
+#define sync_change_bit(nr, p) change_bit(nr, p)
+#define sync_test_and_set_bit(nr, p) test_and_set_bit(nr, p)
+#define sync_test_and_clear_bit(nr, p) test_and_clear_bit(nr, p)
+#define sync_test_and_change_bit(nr, p) test_and_change_bit(nr, p)
+#define sync_test_bit(nr, addr) test_bit(nr, addr)
+#define sync_cmpxchg cmpxchg
+
+#endif