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, 130 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0c8614d9875c..0e6221889ca9 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1035,3 +1035,133 @@ machine_check_in_rtas:
         /* XXX load up BATs and panic */
 
 #endif /* CONFIG_PPC_RTAS */
+
+#ifdef CONFIG_FTRACE
+#ifdef CONFIG_DYNAMIC_FTRACE
+_GLOBAL(mcount)
+_GLOBAL(_mcount)
+        stwu    r1,-48(r1)
+        stw     r3, 12(r1)
+        stw     r4, 16(r1)
+        stw     r5, 20(r1)
+        stw     r6, 24(r1)
+        mflr    r3
+        stw     r7, 28(r1)
+        mfcr    r5
+        stw     r8, 32(r1)
+        stw     r9, 36(r1)
+        stw     r10,40(r1)
+        stw     r3, 44(r1)
+        stw     r5, 8(r1)
+        .globl mcount_call
+mcount_call:
+        bl      ftrace_stub
+        nop
+        lwz     r6, 8(r1)
+        lwz     r0, 44(r1)
+        lwz     r3, 12(r1)
+        mtctr   r0
+        lwz     r4, 16(r1)
+        mtcr    r6
+        lwz     r5, 20(r1)
+        lwz     r6, 24(r1)
+        lwz     r0, 52(r1)
+        lwz     r7, 28(r1)
+        lwz     r8, 32(r1)
+        mtlr    r0
+        lwz     r9, 36(r1)
+        lwz     r10,40(r1)
+        addi    r1, r1, 48
+        bctr
+
+_GLOBAL(ftrace_caller)
+        /* Based off of objdump optput from glibc */
+        stwu    r1,-48(r1)
+        stw     r3, 12(r1)
+        stw     r4, 16(r1)
+        stw     r5, 20(r1)
+        stw     r6, 24(r1)
+        mflr    r3
+        lwz     r4, 52(r1)
+        mfcr    r5
+        stw     r7, 28(r1)
+        stw     r8, 32(r1)
+        stw     r9, 36(r1)
+        stw     r10,40(r1)
+        stw     r3, 44(r1)
+        stw     r5, 8(r1)
+.globl ftrace_call
+ftrace_call:
+        bl      ftrace_stub
+        nop
+        lwz     r6, 8(r1)
+        lwz     r0, 44(r1)
+        lwz     r3, 12(r1)
+        mtctr   r0
+        lwz     r4, 16(r1)
+        mtcr    r6
+        lwz     r5, 20(r1)
+        lwz     r6, 24(r1)
+        lwz     r0, 52(r1)
+        lwz     r7, 28(r1)
+        lwz     r8, 32(r1)
+        mtlr    r0
+        lwz     r9, 36(r1)
+        lwz     r10,40(r1)
+        addi    r1, r1, 48
+        bctr
+#else
+_GLOBAL(mcount)
+_GLOBAL(_mcount)
+        stwu    r1,-48(r1)
+        stw     r3, 12(r1)
+        stw     r4, 16(r1)
+        stw     r5, 20(r1)
+        stw     r6, 24(r1)
+        mflr    r3
+        lwz     r4, 52(r1)
+        mfcr    r5
+        stw     r7, 28(r1)
+        stw     r8, 32(r1)
+        stw     r9, 36(r1)
+        stw     r10,40(r1)
+        stw     r3, 44(r1)
+        stw     r5, 8(r1)
+
+        LOAD_REG_ADDR(r5, ftrace_trace_function)
+#if 0
+        mtctr   r3
+        mr      r1, r5
+        bctrl
+#endif
+        lwz     r5,0(r5)
+#if 1
+        mtctr   r5
+        bctrl
+#else
+        bl      ftrace_stub
+#endif
+        nop
+
+        lwz     r6, 8(r1)
+        lwz     r0, 44(r1)
+        lwz     r3, 12(r1)
+        mtctr   r0
+        lwz     r4, 16(r1)
+        mtcr    r6
+        lwz     r5, 20(r1)
+        lwz     r6, 24(r1)
+        lwz     r0, 52(r1)
+        lwz     r7, 28(r1)
+        lwz     r8, 32(r1)
+        mtlr    r0
+        lwz     r9, 36(r1)
+        lwz     r10,40(r1)
+        addi    r1, r1, 48
+        bctr
+#endif
+
+_GLOBAL(ftrace_stub)
+        blr
+
+#endif /* CONFIG_MCOUNT */