Changeset 4702bde in mainline

Timestamp:

2009-12-02T18:53:26Z (15 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

e15e0e8

Parents:

12bef5b

Message:

Fix atomic addition in arm32 kernel.

File:

• kernel/arch/arm32/include/atomic.h (modified) (2 diffs)

kernel/arch/arm32/include/atomic.h

@@ -37 +37 @@
 #define KERN_arm32_ATOMIC_H_
 
+#include <arch/asm.h>
+
 /** Atomic addition.
  *
@@ -47 +49 @@
 static inline long atomic_add(atomic_t *val, int i)
 {
-        int ret;
-        volatile long *mem = &(val->count);
-        
-        asm volatile (
-                "1:\n"
-                        "ldr r2, [%[mem]]\n"
-                        "add r3, r2, %[i]\n"
-                        "str r3, %[ret]\n"
-                        "swp r3, r3, [%[mem]]\n"
-                        "cmp r3, r2\n"
-                        "bne 1b\n"
-                : [ret] "=m" (ret)
-                : [mem] "r" (mem), [i] "r" (i)
-                : "r3", "r2"
-        );
+        long ret;
+
+        /*
+         * This implementation is for UP pre-ARMv6 systems where we do not have
+         * the LDREX and STREX instructions.
+         */
+        ipl_t ipl = interrupts_disable();
+        val->count += i;
+        ret = val->count;
+        interrupts_restore(ipl);
         
         return ret;