Changeset b17518e in mainline for kernel/arch/ia32/include/atomic.h

Timestamp:

2012-08-05T01:18:21Z (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:

bc216a0

Parents:

f1c7755

Message:

Renamed atomic_swap_* to atmoic_set_return_* and added a local cpu native_t variant.

File:

• kernel/arch/ia32/include/atomic.h (modified) (4 diffs)

kernel/arch/ia32/include/atomic.h

@@ -144 +144 @@
 
 
-#define _atomic_cas_ptr_impl(pptr, exp_val, new_val, old_val, prefix) \
+#define _atomic_cas_impl(pptr, exp_val, new_val, old_val, prefix) \
         asm volatile ( \
                 prefix " cmpxchgl %[newval], %[ptr]\n" \
@@ -165 +165 @@
 {
         void *old_val;
-        _atomic_cas_ptr_impl(pptr, exp_val, new_val, old_val, "lock\n");
+        _atomic_cas_impl(pptr, exp_val, new_val, old_val, "lock\n");
         return old_val;
 }
@@ -177 +177 @@
 {
         void *old_val;
-        _atomic_cas_ptr_impl(pptr, exp_val, new_val, old_val, "");
+        _atomic_cas_impl(pptr, exp_val, new_val, old_val, "");
         return old_val;
 }
 
 
-/** Atomicaly sets *ptr to new_val and returns the previous value. */
-NO_TRACE static inline void * atomic_swap_ptr(void **pptr, void *new_val)
-{
-        void *new_in_old_out = new_val;
-        
-        asm volatile (
-                "xchgl %[val], %[pptr]\n"
-                : [val] "+r" (new_in_old_out),
-                  [pptr] "+m" (*pptr)
-        );
-        
-        return new_in_old_out;
+#define _atomic_swap_impl(pptr, new_val) \
+({ \
+        typeof(*(pptr)) new_in_old_out = new_val; \
+        asm volatile ( \
+                "xchgl %[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);
 }
 
@@ -201 +224 @@
  * NOT atomic wrt to other cpus.
  */
-NO_TRACE static inline void * atomic_swap_ptr_local(void **pptr, void *new_val)
-{
-        /* 
-         * Issuing a xchg instruction always implies lock prefix semantics.
-         * Therefore, it is cheaper to use a cmpxchg without a lock prefix 
-         * in a loop.
-         */
-        void *exp_val;
-        void *old_val;
-        
-        do {
-                exp_val = *pptr;
-                old_val = atomic_cas_ptr_local(pptr, exp_val, new_val);
-        } while (old_val != exp_val);
-        
-        return old_val;
-}
+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