Changeset 2708f6a in mainline for kernel/arch/amd64/include/atomic.h

Timestamp:

2012-11-07T10:59:34Z (12 years ago)

Author:

Adam Hraska <adam.hraska+hos@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

cc106e4

Parents:

c8fccf5

Message:

Removed ia32 and amd64 specific atomic compare-and-swap operations (use compiler builtins instead).

File:

• kernel/arch/amd64/include/atomic.h (modified) (1 diff)

kernel/arch/amd64/include/atomic.h

@@ -141 +141 @@
 
 
-#define _atomic_cas_impl(pptr, exp_val, new_val, old_val, prefix) \
-        asm volatile ( \
-                prefix " cmpxchgq %[newval], %[ptr]\n" \
-                : /* Output operands. */ \
-                /* Old/current value is returned in eax. */ \
-                [oldval] "=a" (old_val), \
-                /* (*ptr) will be read and written to, hence "+" */ \
-                [ptr] "+m" (*pptr) \
-                : /* Input operands. */ \
-                /* Expected value must be in eax. */ \
-                [expval] "a" (exp_val), \
-                /* The new value may be in any register. */ \
-                [newval] "r" (new_val) \
-                : "memory" \
-        )
-        
-/** Atomically compares and swaps the pointer at pptr. */
-NO_TRACE static inline void * atomic_cas_ptr(void **pptr, 
-        void *exp_val, void *new_val)
-{
-        void *old_val;
-        _atomic_cas_impl(pptr, exp_val, new_val, old_val, "lock\n");
-        return old_val;
-}
-
-/** Compare-and-swap of a pointer that is atomic wrt to local cpu's interrupts.
- * 
- * This function is NOT smp safe and is not atomic with respect to other cpus.
- */
-NO_TRACE static inline void * atomic_cas_ptr_local(void **pptr, 
-        void *exp_val, void *new_val)
-{
-        void *old_val;
-        _atomic_cas_impl(pptr, exp_val, new_val, old_val, "");
-        return old_val;
-}
-
-
-#define _atomic_swap_impl(pptr, new_val) \
-({ \
-        typeof(*(pptr)) new_in_old_out = new_val; \
-        asm volatile ( \
-                "xchgq %[val], %[p_ptr]\n" \
-                : [val] "+r" (new_in_old_out), \
-                  [p_ptr] "+m" (*pptr) \
-        ); \
-        \
-        new_in_old_out; \
-})
-
-/* 
- * Issuing a xchg instruction always implies lock prefix semantics.
- * Therefore, it is cheaper to use a cmpxchg without a lock prefix 
- * in a loop.
- */
-#define _atomic_swap_local_impl(pptr, new_val) \
-({ \
-        typeof(*(pptr)) exp_val; \
-        typeof(*(pptr)) old_val; \
-        \
-        do { \
-                exp_val = *pptr; \
-                _atomic_cas_impl(pptr, exp_val, new_val, old_val, ""); \
-        } while (old_val != exp_val); \
-        \
-        old_val; \
-})
-
-
-/** Atomicaly sets *ptr to val and returns the previous value. */
-NO_TRACE static inline void * atomic_set_return_ptr(void **pptr, void *val)
-{
-        return _atomic_swap_impl(pptr, val);
-}
-
-/** Sets *ptr to new_val and returns the previous value. NOT smp safe.
- * 
- * This function is only atomic wrt to local interrupts and it is
- * NOT atomic wrt to other cpus.
- */
-NO_TRACE static inline void * atomic_set_return_ptr_local(
-        void **pptr, void *new_val)
-{
-        return _atomic_swap_local_impl(pptr, new_val);
-}
-
-/** Atomicaly sets *ptr to val and returns the previous value. */
-NO_TRACE static inline native_t atomic_set_return_native_t(
-        native_t *p, native_t val)
-{
-        return _atomic_swap_impl(p, val);
-}
-
-/** Sets *ptr to new_val and returns the previous value. NOT smp safe.
- * 
- * This function is only atomic wrt to local interrupts and it is
- * NOT atomic wrt to other cpus.
- */
-NO_TRACE static inline native_t atomic_set_return_native_t_local(
-        native_t *p, native_t new_val)
-{
-        return _atomic_swap_local_impl(p, new_val);
-}
-
-
-#undef _atomic_cas_ptr_impl
-#undef _atomic_swap_impl
-#undef _atomic_swap_local_impl
-
 #endif