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Diffstat (limited to 'linux-2.4.26-xen-sparse/include/asm-xen/synch_bitops.h')
-rw-r--r--linux-2.4.26-xen-sparse/include/asm-xen/synch_bitops.h83
1 files changed, 83 insertions, 0 deletions
diff --git a/linux-2.4.26-xen-sparse/include/asm-xen/synch_bitops.h b/linux-2.4.26-xen-sparse/include/asm-xen/synch_bitops.h
new file mode 100644
index 0000000000..8093de0ac9
--- /dev/null
+++ b/linux-2.4.26-xen-sparse/include/asm-xen/synch_bitops.h
@@ -0,0 +1,83 @@
+#ifndef __XEN_SYNCH_BITOPS_H__
+#define __XEN_SYNCH_BITOPS_H__
+
+/*
+ * Copyright 1992, Linus Torvalds.
+ * Heavily modified to provide guaranteed strong synchronisation
+ * when communicating with Xen or other guest OSes running on other CPUs.
+ */
+
+#include <linux/config.h>
+
+#define ADDR (*(volatile long *) addr)
+
+static __inline__ void synch_set_bit(int nr, volatile void * addr)
+{
+ __asm__ __volatile__ (
+ "lock btsl %1,%0"
+ : "=m" (ADDR) : "Ir" (nr) : "memory" );
+}
+
+static __inline__ void synch_clear_bit(int nr, volatile void * addr)
+{
+ __asm__ __volatile__ (
+ "lock btrl %1,%0"
+ : "=m" (ADDR) : "Ir" (nr) : "memory" );
+}
+
+static __inline__ void synch_change_bit(int nr, volatile void * addr)
+{
+ __asm__ __volatile__ (
+ "lock btcl %1,%0"
+ : "=m" (ADDR) : "Ir" (nr) : "memory" );
+}
+
+static __inline__ int synch_test_and_set_bit(int nr, volatile void * addr)
+{
+ int oldbit;
+ __asm__ __volatile__ (
+ "lock btsl %2,%1\n\tsbbl %0,%0"
+ : "=r" (oldbit), "=m" (ADDR) : "Ir" (nr) : "memory");
+ return oldbit;
+}
+
+static __inline__ int synch_test_and_clear_bit(int nr, volatile void * addr)
+{
+ int oldbit;
+ __asm__ __volatile__ (
+ "lock btrl %2,%1\n\tsbbl %0,%0"
+ : "=r" (oldbit), "=m" (ADDR) : "Ir" (nr) : "memory");
+ return oldbit;
+}
+
+static __inline__ int synch_test_and_change_bit(int nr, volatile void * addr)
+{
+ int oldbit;
+
+ __asm__ __volatile__ (
+ "lock btcl %2,%1\n\tsbbl %0,%0"
+ : "=r" (oldbit), "=m" (ADDR) : "Ir" (nr) : "memory");
+ return oldbit;
+}
+
+static __inline__ int synch_const_test_bit(int nr, const volatile void * addr)
+{
+ return ((1UL << (nr & 31)) &
+ (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
+}
+
+static __inline__ int synch_var_test_bit(int nr, volatile void * addr)
+{
+ int oldbit;
+ __asm__ __volatile__ (
+ "btl %2,%1\n\tsbbl %0,%0"
+ : "=r" (oldbit) : "m" (ADDR), "Ir" (nr) );
+ return oldbit;
+}
+
+#define synch_test_bit(nr,addr) \
+(__builtin_constant_p(nr) ? \
+ synch_const_test_bit((nr),(addr)) : \
+ synch_var_test_bit((nr),(addr)))
+
+#endif /* __XEN_SYNCH_BITOPS_H__ */