Re: [PATCH v1 2/4] powerpc/ftrace: Refactor ftrace_{regs_}caller

From: Naveen N. Rao
Date: Thu Mar 03 2022 - 12:00:26 EST


Christophe Leroy wrote:
ftrace_caller() and frace_regs_caller() have now a lot in common.

Refactor them using GAS macros.

Thanks for doing this - this looks much better.


Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/kernel/trace/ftrace_mprofile.S | 147 ++++++--------------
1 file changed, 45 insertions(+), 102 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace_mprofile.S b/arch/powerpc/kernel/trace/ftrace_mprofile.S
index 76dab07fd8fd..630b2de9957b 100644
--- a/arch/powerpc/kernel/trace/ftrace_mprofile.S
+++ b/arch/powerpc/kernel/trace/ftrace_mprofile.S
@@ -32,7 +32,7 @@
* Our job is to save the register state into a struct pt_regs (on the stack)
* and then arrange for the ftrace function to be called.
*/
-_GLOBAL(ftrace_regs_caller)
+.macro ftrace_regs_entry allregs
/* Save the original return address in A's stack frame */
#ifdef CONFIG_MPROFILE_KERNEL
PPC_STL r0,LRSAVE(r1)
@@ -43,7 +43,7 @@ _GLOBAL(ftrace_regs_caller)

/* Save all gprs to pt_regs */
SAVE_GPR(0, r1)
- SAVE_GPRS(2, 11, r1)
+ SAVE_GPRS(3, 10, r1)

#ifdef CONFIG_PPC64
/* Ok to continue? */
@@ -52,17 +52,29 @@ _GLOBAL(ftrace_regs_caller)
beq ftrace_no_trace
#endif

The ability to disable ftrace in certain code paths through paca_struct->ftrace_enabled will also be relevant on ppc32 - it will be nice if it can be introduced there.

For this series though:
Reviewed-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>


- Naveen