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authorJiri Kosina <jkosina@suse.cz>2012-10-28 19:28:52 +0100
committerJiri Kosina <jkosina@suse.cz>2012-10-28 19:29:19 +0100
commit3bd7bf1f0fe14f591c089ae61bbfa9bd356f178a (patch)
tree0058693cc9e70b7461dae551f8a19aff2efd13ca /arch/arm/include/asm/sync_bitops.h
parentf16f84937d769c893492160b1a8c3672e3992beb (diff)
parente657e078d3dfa9f96976db7a2b5fd7d7c9f1f1a6 (diff)
Merge branch 'master' into for-next
Sync up with Linus' tree to be able to apply Cesar's patch against newer version of the code. Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'arch/arm/include/asm/sync_bitops.h')
-rw-r--r--arch/arm/include/asm/sync_bitops.h27
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/arm/include/asm/sync_bitops.h b/arch/arm/include/asm/sync_bitops.h
new file mode 100644
index 00000000000..63479eecbf7
--- /dev/null
+++ b/arch/arm/include/asm/sync_bitops.h
@@ -0,0 +1,27 @@
+#ifndef __ASM_SYNC_BITOPS_H__
+#define __ASM_SYNC_BITOPS_H__
+
+#include <asm/bitops.h>
+#include <asm/system.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