Implemented the atomic functions to get in touch with PPC assembly.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@3196 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kernel/libroot/os/arch/ppc/Jamfile

@@ -1,7 +1,7 @@
 SubDir OBOS_TOP src kernel libroot os arch ppc ;
 
 KernelMergeObject os_arch_$(OBOS_ARCH).o :
-#	<$(SOURCE_GRIST)>atomic.S
+	<$(SOURCE_GRIST)>atomic.S
 #	<$(SOURCE_GRIST)>cpuid.S
 #	<$(SOURCE_GRIST)>systeminfo.c
 #	<$(SOURCE_GRIST)>thread.c
@@ -11,7 +11,6 @@ KernelMergeObject os_arch_$(OBOS_ARCH).o :
 	;
 
 MergeObjectFromObjects kernel_os_arch_$(OBOS_ARCH).o :
-	# ToDo: remove atomic_xxx() functions from the kernel's libx86.a
-	#<$(SOURCE_GRIST)>atomic.o
+	<$(SOURCE_GRIST)>atomic.o
 	#<$(SOURCE_GRIST)>cpuid.o
 	;

src/kernel/libroot/os/arch/ppc/atomic.S

@@ -0,0 +1,63 @@
+/*
+** Copyright 2003, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
+** Distributed under the terms of the OpenBeOS License.
+*/
+
+#define FUNCTION(x) .global x; .type x,@function; x
+
+.text
+
+/* int atomic_add(int *value, int increment)
+ *                r3          r4
+ */
+FUNCTION(atomic_add):
+lost1:	lwarx	%r5, 0, %r3		// reserve memory address located in "r3"
+		add		%r0, %r5, %r4	// (contents are stored in "r5")
+		stwcx.	%r0, 0, %r3
+		bne-	lost1			// try again if reservation was lost
+		mr		%r3, %r5		// return old value (was in "r5")
+		blr
+
+/* int atomic_and(int *value, int andValue)
+ *                r3          r4
+ */
+FUNCTION(atomic_and):
+lost2:	lwarx	%r5, 0, %r3
+		and		%r0, %r5, %r4
+		stwcx.	%r0, 0, %r3
+		bne-	lost2
+		mr		%r3, %r5
+		blr
+
+/* int atomic_or(int *value, int orValue)
+ *               r3          r4
+ */
+FUNCTION(atomic_or):
+lost3:	lwarx	%r5, 0, %r3
+		or		%r0, %r5, %r4
+		stwcx.	%r0, 0, %r3
+		bne-	lost3
+		mr		%r3, %r5
+		blr
+
+/* int atomic_set(int *value, int setTo)
+ *                r3          r4
+ */
+FUNCTION(atomic_set):
+lost4:	lwarx	%r5, 0, %r3
+		stwcx.	%r4, 0, %r3
+		bne-	lost4
+		mr		%r3, %r5
+		blr
+
+/* int test_and_set(int *value, int setTo, int testValue) 
+ *                  r3          r4         r5
+ */
+FUNCTION(test_and_set):
+lost5:	lwarx	%r6, 0, %r3
+		cmpw	%r6, %r5
+		bne		out5
+		stwcx.	%r4, 0, %r3
+out5:	mr		%r3, %r6
+		blr
+