powerpc64: port of the function graph tracer

[deliverable/linux.git] / arch / powerpc / kernel / entry_64.S

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 383ed6eb00850d2a7ab89b3b54b4677a3b9b1478..a32699e74c3cf94d21316bab96362ed17f6a8fc9 100644 (file)
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -931,13 +931,65 @@ _GLOBAL(_mcount)
        ld      r5,0(r5)
        mtctr   r5
        bctrl
-
        nop
+
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+       b       ftrace_graph_caller
+#endif
        ld      r0, 128(r1)
        mtlr    r0
        addi    r1, r1, 112
 _GLOBAL(ftrace_stub)
        blr
 
-#endif
-#endif
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ftrace_graph_caller:
+       /* load r4 with local address */
+       ld      r4, 128(r1)
+       subi    r4, r4, MCOUNT_INSN_SIZE
+
+       /* get the parent address */
+       ld      r11, 112(r1)
+       addi    r3, r11, 16
+
+       bl      .prepare_ftrace_return
+       nop
+
+       ld      r0, 128(r1)
+       mtlr    r0
+       addi    r1, r1, 112
+       blr
+
+_GLOBAL(return_to_handler)
+       /* need to save return values */
+       std     r4,  -32(r1)
+       std     r3,  -24(r1)
+       /* save TOC */
+       std     r2,  -16(r1)
+       std     r31, -8(r1)
+       mr      r31, r1
+       stdu    r1, -112(r1)
+
+       /* update the TOC */
+       LOAD_REG_IMMEDIATE(r4,ftrace_return_to_handler)
+       ld      r2, 8(r4)
+
+       bl      .ftrace_return_to_handler
+       nop
+
+       /* return value has real return address */
+       mtlr    r3
+
+       ld      r1, 0(r1)
+       ld      r4,  -32(r1)
+       ld      r3,  -24(r1)
+       ld      r2,  -16(r1)
+       ld      r31, -8(r1)
+
+       /* Jump back to real return address */
+       blr
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+#endif /* CONFIG_FUNCTION_TRACER */