diff options
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.h | 83 |
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__ */ |