first commit

1 files changed, 31 insertions, 0 deletions

diff --git a/arch/arm64/lib/call_with_stack.S b/arch/arm64/lib/call_with_stack.S
new file mode 100644
index 000000000..6f527fe50
--- /dev/null
+++ b/arch/arm64/lib/call_with_stack.S
@@ -0,0 +1,31 @@
+/*
+ * arch/arm64/lib/call_with_stack.S
+ *
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+/*
+ * void call_with_stack(void (*fn)(void *), void *arg, void *sp)
+ *
+ * Change the stack to that pointed at by sp, then invoke fn(arg) with
+ * the new stack.
+ */
+ENTRY(call_with_stack)
+        mov     x3, sp
+	str	x3, [x2, #-8]!
+	str	lr, [x2, #-8]!
+
+	mov	sp, x2
+	mov	x2, x0
+	mov	x0, x1
+
+	adr	lr, 1f
+	br	x2
+
+1:	ldr	lr, [sp]
+	ldr	x3, [sp, #8]
+        mov     sp, x3
+	br	lr
+ENDPROC(call_with_stack)