ftrace: support for PowerPC

This patch adds full support for ftrace for PowerPC (both 64 and 32 bit).
This includes dynamic tracing and function filtering.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 62 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index c0db5b769e55..2c4d9e056ead 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -870,3 +870,65 @@ _GLOBAL(enter_prom)
         ld      r0,16(r1)
         mtlr    r0
         blr
+
+#ifdef CONFIG_FTRACE
+#ifdef CONFIG_DYNAMIC_FTRACE
+_GLOBAL(mcount)
+_GLOBAL(_mcount)
+        /* Taken from output of objdump from lib64/glibc */
+        mflr    r3
+        stdu    r1, -112(r1)
+        std     r3, 128(r1)
+        .globl mcount_call
+mcount_call:
+        bl      ftrace_stub
+        nop
+        ld      r0, 128(r1)
+        mtlr    r0
+        addi    r1, r1, 112
+        blr
+
+_GLOBAL(ftrace_caller)
+        /* Taken from output of objdump from lib64/glibc */
+        mflr    r3
+        ld      r11, 0(r1)
+        stdu    r1, -112(r1)
+        std     r3, 128(r1)
+        ld      r4, 16(r11)
+.globl ftrace_call
+ftrace_call:
+        bl      ftrace_stub
+        nop
+        ld      r0, 128(r1)
+        mtlr    r0
+        addi    r1, r1, 112
+_GLOBAL(ftrace_stub)
+        blr
+#else
+_GLOBAL(mcount)
+        blr
+
+_GLOBAL(_mcount)
+        /* Taken from output of objdump from lib64/glibc */
+        mflr    r3
+        ld      r11, 0(r1)
+        stdu    r1, -112(r1)
+        std     r3, 128(r1)
+        ld      r4, 16(r11)
+
+
+        LOAD_REG_ADDR(r5,ftrace_trace_function)
+        ld      r5,0(r5)
+        ld      r5,0(r5)
+        mtctr   r5
+        bctrl
+
+        nop
+        ld      r0, 128(r1)
+        mtlr    r0
+        addi    r1, r1, 112
+_GLOBAL(ftrace_stub)
+        blr
+
+#endif
+#endif