Index: kernel/arch/riscv64/include/arch/atomic.h
===================================================================
--- kernel/arch/riscv64/include/arch/atomic.h	(revision 0a78e4fc664e59673629dee0fb20855def1120d4)
+++ kernel/arch/riscv64/include/arch/atomic.h	(revision bb3ba5137bd607b9877ff92aaf085748b2ab8fda)
@@ -40,34 +40,70 @@
 NO_TRACE static inline void atomic_inc(atomic_t *val)
 {
-	// FIXME
+	asm volatile (
+		"amoadd.d zero, %[inc], %[addr]\n"
+		: [addr] "+A" (val->count)
+		: [inc] "r" (1)
+	);
 }
 
 NO_TRACE static inline void atomic_dec(atomic_t *val)
 {
-	// FIXME
+	asm volatile (
+		"amoadd.d zero, %[inc], %[addr]\n"
+		: [addr] "+A" (val->count)
+		: [inc] "r" (-1)
+	);
 }
 
 NO_TRACE static inline atomic_count_t atomic_postinc(atomic_t *val)
 {
-	atomic_inc(val);
-	return val->count - 1;
+	atomic_count_t orig;
+	
+	asm volatile (
+		"amoadd.d %[orig], %[inc], %[addr]\n"
+		: [orig] "=r" (orig), [addr] "+A" (val->count)
+		: [inc] "r" (1)
+	);
+	
+	return orig;
 }
 
 NO_TRACE static inline atomic_count_t atomic_postdec(atomic_t *val)
 {
-	atomic_dec(val);
-	return val->count + 1;
+	atomic_count_t orig;
+	
+	asm volatile (
+		"amoadd.d %[orig], %[inc], %[addr]\n"
+		: [orig] "=r" (orig), [addr] "+A" (val->count)
+		: [inc] "r" (-1)
+	);
+	
+	return orig;
 }
 
 NO_TRACE static inline atomic_count_t atomic_preinc(atomic_t *val)
 {
-	atomic_inc(val);
-	return val->count;
+	atomic_count_t orig;
+	
+	asm volatile (
+		"amoadd.d %[orig], %[inc], %[addr]\n"
+		: [orig] "=r" (orig), [addr] "+A" (val->count)
+		: [inc] "r" (1)
+	);
+	
+	return orig - 1;
 }
 
 NO_TRACE static inline atomic_count_t atomic_predec(atomic_t *val)
 {
-	atomic_dec(val);
-	return val->count;
+	atomic_count_t orig;
+	
+	asm volatile (
+		"amoadd.d %[orig], %[inc], %[addr]\n"
+		: [orig] "=r" (orig), [addr] "+A" (val->count)
+		: [inc] "r" (-1)
+	);
+	
+	return orig + 1;
 }