From: Michael Ellerman Date: Tue, 7 Feb 2017 10:01:01 +0000 (+1100) Subject: powerpc/powernv: Fix opal_exit tracepoint opcode X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a7e0fb6c2029a780444d09560f739e020d54fe4d;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git powerpc/powernv: Fix opal_exit tracepoint opcode Currently the opal_exit tracepoint usually shows the opcode as 0: -0 [047] d.h. 635.654292: opal_entry: opcode=63 -0 [047] d.h. 635.654296: opal_exit: opcode=0 retval=0 kopald-1209 [019] d... 636.420943: opal_entry: opcode=10 kopald-1209 [019] d... 636.420959: opal_exit: opcode=0 retval=0 This is because we incorrectly load the opcode into r0 before calling __trace_opal_exit(), whereas it expects the opcode in r3 (first function parameter). In fact we are leaving the retval in r3, so opcode and retval will always show the same value. Instead load the opcode into r3, resulting in: -0 [040] d.h. 636.618625: opal_entry: opcode=63 -0 [040] d.h. 636.618627: opal_exit: opcode=63 retval=0 Fixes: c49f63530bb6 ("powernv: Add OPAL tracepoints") Signed-off-by: Michael Ellerman --- diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S index f7c19c9c57ed..63fe1b2b1175 100644 --- a/arch/powerpc/platforms/powernv/opal-wrappers.S +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S @@ -146,7 +146,7 @@ opal_tracepoint_entry: opal_tracepoint_return: std r3,STK_REG(R31)(r1) mr r4,r3 - ld r0,STK_REG(R23)(r1) + ld r3,STK_REG(R23)(r1) bl __trace_opal_exit ld r3,STK_REG(R31)(r1) addi r1,r1,STACKFRAMESIZE