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Message-ID: <20241018173632.277333-17-hbathini@linux.ibm.com>
Date: Fri, 18 Oct 2024 23:06:31 +0530
From: Hari Bathini <hbathini@...ux.ibm.com>
To: linuxppc-dev <linuxppc-dev@...ts.ozlabs.org>, bpf@...r.kernel.org,
linux-trace-kernel@...r.kernel.org, linux-kbuild@...r.kernel.org,
linux-kernel@...r.kernel.org
Cc: Michael Ellerman <mpe@...erman.id.au>, "Naveen N. Rao" <naveen@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Daniel Borkmann <daniel@...earbox.net>,
Masahiro Yamada <masahiroy@...nel.org>,
Nicholas Piggin <npiggin@...il.com>,
Alexei Starovoitov <ast@...nel.org>,
Steven Rostedt <rostedt@...dmis.org>,
Masami Hiramatsu <mhiramat@...nel.org>,
Andrii Nakryiko <andrii@...nel.org>,
Christophe Leroy <christophe.leroy@...roup.eu>,
Vishal Chourasia <vishalc@...ux.ibm.com>,
Mahesh J Salgaonkar <mahesh@...ux.ibm.com>
Subject: [PATCH v6 16/17] samples/ftrace: Add support for ftrace direct samples on powerpc
From: Naveen N Rao <naveen@...nel.org>
Add powerpc 32-bit and 64-bit samples for ftrace direct. This serves to
show the sample instruction sequence to be used by ftrace direct calls
to adhere to the ftrace ABI.
On 64-bit powerpc, TOC setup requires some additional work.
Signed-off-by: Naveen N Rao <naveen@...nel.org>
---
arch/powerpc/Kconfig | 2 +
samples/ftrace/ftrace-direct-modify.c | 85 +++++++++++++++-
samples/ftrace/ftrace-direct-multi-modify.c | 101 +++++++++++++++++++-
samples/ftrace/ftrace-direct-multi.c | 79 ++++++++++++++-
samples/ftrace/ftrace-direct-too.c | 83 +++++++++++++++-
samples/ftrace/ftrace-direct.c | 69 ++++++++++++-
6 files changed, 414 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 6ede14e55ee1..c85470b24118 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -275,6 +275,8 @@ config PPC
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RELIABLE_STACKTRACE
select HAVE_RSEQ
+ select HAVE_SAMPLE_FTRACE_DIRECT if HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+ select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
select HAVE_SETUP_PER_CPU_AREA if PPC64
select HAVE_SOFTIRQ_ON_OWN_STACK
select HAVE_STACKPROTECTOR if PPC32 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r2)
diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
index 81220390851a..cfea7a38befb 100644
--- a/samples/ftrace/ftrace-direct-modify.c
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -2,7 +2,7 @@
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/ftrace.h>
-#ifndef CONFIG_ARM64
+#if !defined(CONFIG_ARM64) && !defined(CONFIG_PPC32)
#include <asm/asm-offsets.h>
#endif
@@ -199,6 +199,89 @@ asm (
#endif /* CONFIG_LOONGARCH */
+#ifdef CONFIG_PPC
+#include <asm/ppc_asm.h>
+
+#ifdef CONFIG_PPC64
+#define STACK_FRAME_SIZE 48
+#else
+#define STACK_FRAME_SIZE 24
+#endif
+
+#if defined(CONFIG_PPC64_ELF_ABI_V2) && !defined(CONFIG_PPC_KERNEL_PCREL)
+#define PPC64_TOC_SAVE_AND_UPDATE \
+" std 2, 24(1)\n" \
+" bcl 20, 31, 1f\n" \
+" 1: mflr 12\n" \
+" ld 2, (99f - 1b)(12)\n"
+#define PPC64_TOC_RESTORE \
+" ld 2, 24(1)\n"
+#define PPC64_TOC \
+" 99: .quad .TOC.@...base\n"
+#else
+#define PPC64_TOC_SAVE_AND_UPDATE ""
+#define PPC64_TOC_RESTORE ""
+#define PPC64_TOC ""
+#endif
+
+#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE
+#define PPC_FTRACE_RESTORE_LR \
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n" \
+" mtlr 0\n"
+#define PPC_FTRACE_RET \
+" blr\n"
+#else
+#define PPC_FTRACE_RESTORE_LR \
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n" \
+" mtctr 0\n"
+#define PPC_FTRACE_RET \
+" mtlr 0\n" \
+" bctr\n"
+#endif
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+" mflr 0\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_SIZE)"(1)\n"
+ PPC64_TOC_SAVE_AND_UPDATE
+" bl my_direct_func1\n"
+ PPC64_TOC_RESTORE
+" addi 1, 1, "__stringify(STACK_FRAME_SIZE)"\n"
+ PPC_FTRACE_RESTORE_LR
+" addi 1, 1, "__stringify(STACK_FRAME_MIN_SIZE)"\n"
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_FTRACE_RET
+" .size my_tramp1, .-my_tramp1\n"
+
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+" mflr 0\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_SIZE)"(1)\n"
+ PPC64_TOC_SAVE_AND_UPDATE
+" bl my_direct_func2\n"
+ PPC64_TOC_RESTORE
+" addi 1, 1, "__stringify(STACK_FRAME_SIZE)"\n"
+ PPC_FTRACE_RESTORE_LR
+" addi 1, 1, "__stringify(STACK_FRAME_MIN_SIZE)"\n"
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_FTRACE_RET
+ PPC64_TOC
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_PPC */
+
static struct ftrace_ops direct;
static unsigned long my_tramp = (unsigned long)my_tramp1;
diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
index f943e40d57fd..8f7986d698d8 100644
--- a/samples/ftrace/ftrace-direct-multi-modify.c
+++ b/samples/ftrace/ftrace-direct-multi-modify.c
@@ -2,7 +2,7 @@
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/ftrace.h>
-#ifndef CONFIG_ARM64
+#if !defined(CONFIG_ARM64) && !defined(CONFIG_PPC32)
#include <asm/asm-offsets.h>
#endif
@@ -225,6 +225,105 @@ asm (
#endif /* CONFIG_LOONGARCH */
+#ifdef CONFIG_PPC
+#include <asm/ppc_asm.h>
+
+#ifdef CONFIG_PPC64
+#define STACK_FRAME_SIZE 48
+#else
+#define STACK_FRAME_SIZE 24
+#endif
+
+#if defined(CONFIG_PPC64_ELF_ABI_V2) && !defined(CONFIG_PPC_KERNEL_PCREL)
+#define PPC64_TOC_SAVE_AND_UPDATE \
+" std 2, 24(1)\n" \
+" bcl 20, 31, 1f\n" \
+" 1: mflr 12\n" \
+" ld 2, (99f - 1b)(12)\n"
+#define PPC64_TOC_RESTORE \
+" ld 2, 24(1)\n"
+#define PPC64_TOC \
+" 99: .quad .TOC.@...base\n"
+#else
+#define PPC64_TOC_SAVE_AND_UPDATE ""
+#define PPC64_TOC_RESTORE ""
+#define PPC64_TOC ""
+#endif
+
+#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE
+#define PPC_FTRACE_RESTORE_LR \
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n" \
+" mtlr 0\n"
+#define PPC_FTRACE_RET \
+" blr\n"
+#define PPC_FTRACE_RECOVER_IP \
+" lwz 8, 4(3)\n" \
+" li 9, 6\n" \
+" slw 8, 8, 9\n" \
+" sraw 8, 8, 9\n" \
+" add 3, 3, 8\n" \
+" addi 3, 3, 4\n"
+#else
+#define PPC_FTRACE_RESTORE_LR \
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n" \
+" mtctr 0\n"
+#define PPC_FTRACE_RET \
+" mtlr 0\n" \
+" bctr\n"
+#define PPC_FTRACE_RECOVER_IP ""
+#endif
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+" mflr 0\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_SIZE)"(1)\n"
+ PPC64_TOC_SAVE_AND_UPDATE
+ PPC_STL" 3, "__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+" mr 3, 0\n"
+ PPC_FTRACE_RECOVER_IP
+" bl my_direct_func1\n"
+ PPC_LL" 3, "__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+ PPC64_TOC_RESTORE
+" addi 1, 1, "__stringify(STACK_FRAME_SIZE)"\n"
+ PPC_FTRACE_RESTORE_LR
+" addi 1, 1, "__stringify(STACK_FRAME_MIN_SIZE)"\n"
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_FTRACE_RET
+" .size my_tramp1, .-my_tramp1\n"
+
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+" mflr 0\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_SIZE)"(1)\n"
+ PPC64_TOC_SAVE_AND_UPDATE
+ PPC_STL" 3, "__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+" mr 3, 0\n"
+ PPC_FTRACE_RECOVER_IP
+" bl my_direct_func2\n"
+ PPC_LL" 3, "__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+ PPC64_TOC_RESTORE
+" addi 1, 1, "__stringify(STACK_FRAME_SIZE)"\n"
+ PPC_FTRACE_RESTORE_LR
+" addi 1, 1, "__stringify(STACK_FRAME_MIN_SIZE)"\n"
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_FTRACE_RET
+ PPC64_TOC
+ " .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_PPC */
+
static unsigned long my_tramp = (unsigned long)my_tramp1;
static unsigned long tramps[2] = {
(unsigned long)my_tramp1,
diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
index aed6df2927ce..db326c81a27d 100644
--- a/samples/ftrace/ftrace-direct-multi.c
+++ b/samples/ftrace/ftrace-direct-multi.c
@@ -4,7 +4,7 @@
#include <linux/mm.h> /* for handle_mm_fault() */
#include <linux/ftrace.h>
#include <linux/sched/stat.h>
-#ifndef CONFIG_ARM64
+#if !defined(CONFIG_ARM64) && !defined(CONFIG_PPC32)
#include <asm/asm-offsets.h>
#endif
@@ -141,6 +141,83 @@ asm (
#endif /* CONFIG_LOONGARCH */
+#ifdef CONFIG_PPC
+#include <asm/ppc_asm.h>
+
+#ifdef CONFIG_PPC64
+#define STACK_FRAME_SIZE 48
+#else
+#define STACK_FRAME_SIZE 24
+#endif
+
+#if defined(CONFIG_PPC64_ELF_ABI_V2) && !defined(CONFIG_PPC_KERNEL_PCREL)
+#define PPC64_TOC_SAVE_AND_UPDATE \
+" std 2, 24(1)\n" \
+" bcl 20, 31, 1f\n" \
+" 1: mflr 12\n" \
+" ld 2, (99f - 1b)(12)\n"
+#define PPC64_TOC_RESTORE \
+" ld 2, 24(1)\n"
+#define PPC64_TOC \
+" 99: .quad .TOC.@...base\n"
+#else
+#define PPC64_TOC_SAVE_AND_UPDATE ""
+#define PPC64_TOC_RESTORE ""
+#define PPC64_TOC ""
+#endif
+
+#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE
+#define PPC_FTRACE_RESTORE_LR \
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n" \
+" mtlr 0\n"
+#define PPC_FTRACE_RET \
+" blr\n"
+#define PPC_FTRACE_RECOVER_IP \
+" lwz 8, 4(3)\n" \
+" li 9, 6\n" \
+" slw 8, 8, 9\n" \
+" sraw 8, 8, 9\n" \
+" add 3, 3, 8\n" \
+" addi 3, 3, 4\n"
+#else
+#define PPC_FTRACE_RESTORE_LR \
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n" \
+" mtctr 0\n"
+#define PPC_FTRACE_RET \
+" mtlr 0\n" \
+" bctr\n"
+#define PPC_FTRACE_RECOVER_IP ""
+#endif
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+" mflr 0\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_SIZE)"(1)\n"
+ PPC64_TOC_SAVE_AND_UPDATE
+ PPC_STL" 3, "__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+" mr 3, 0\n"
+ PPC_FTRACE_RECOVER_IP
+" bl my_direct_func\n"
+ PPC_LL" 3, "__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+ PPC64_TOC_RESTORE
+" addi 1, 1, "__stringify(STACK_FRAME_SIZE)"\n"
+ PPC_FTRACE_RESTORE_LR
+" addi 1, 1, "__stringify(STACK_FRAME_MIN_SIZE)"\n"
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_FTRACE_RET
+ PPC64_TOC
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_PPC */
+
static struct ftrace_ops direct;
static int __init ftrace_direct_multi_init(void)
diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
index 6ff546a5d7eb..3d0fa260332d 100644
--- a/samples/ftrace/ftrace-direct-too.c
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -3,7 +3,7 @@
#include <linux/mm.h> /* for handle_mm_fault() */
#include <linux/ftrace.h>
-#ifndef CONFIG_ARM64
+#if !defined(CONFIG_ARM64) && !defined(CONFIG_PPC32)
#include <asm/asm-offsets.h>
#endif
@@ -153,6 +153,87 @@ asm (
#endif /* CONFIG_LOONGARCH */
+#ifdef CONFIG_PPC
+#include <asm/ppc_asm.h>
+
+#ifdef CONFIG_PPC64
+#define STACK_FRAME_SIZE 64
+#define STACK_FRAME_ARG1 32
+#define STACK_FRAME_ARG2 40
+#define STACK_FRAME_ARG3 48
+#define STACK_FRAME_ARG4 56
+#else
+#define STACK_FRAME_SIZE 32
+#define STACK_FRAME_ARG1 16
+#define STACK_FRAME_ARG2 20
+#define STACK_FRAME_ARG3 24
+#define STACK_FRAME_ARG4 28
+#endif
+
+#if defined(CONFIG_PPC64_ELF_ABI_V2) && !defined(CONFIG_PPC_KERNEL_PCREL)
+#define PPC64_TOC_SAVE_AND_UPDATE \
+" std 2, 24(1)\n" \
+" bcl 20, 31, 1f\n" \
+" 1: mflr 12\n" \
+" ld 2, (99f - 1b)(12)\n"
+#define PPC64_TOC_RESTORE \
+" ld 2, 24(1)\n"
+#define PPC64_TOC \
+" 99: .quad .TOC.@...base\n"
+#else
+#define PPC64_TOC_SAVE_AND_UPDATE ""
+#define PPC64_TOC_RESTORE ""
+#define PPC64_TOC ""
+#endif
+
+#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE
+#define PPC_FTRACE_RESTORE_LR \
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n" \
+" mtlr 0\n"
+#define PPC_FTRACE_RET \
+" blr\n"
+#else
+#define PPC_FTRACE_RESTORE_LR \
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n" \
+" mtctr 0\n"
+#define PPC_FTRACE_RET \
+" mtlr 0\n" \
+" bctr\n"
+#endif
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+" mflr 0\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_SIZE)"(1)\n"
+ PPC64_TOC_SAVE_AND_UPDATE
+ PPC_STL" 3, "__stringify(STACK_FRAME_ARG1)"(1)\n"
+ PPC_STL" 4, "__stringify(STACK_FRAME_ARG2)"(1)\n"
+ PPC_STL" 5, "__stringify(STACK_FRAME_ARG3)"(1)\n"
+ PPC_STL" 6, "__stringify(STACK_FRAME_ARG4)"(1)\n"
+" bl my_direct_func\n"
+ PPC_LL" 6, "__stringify(STACK_FRAME_ARG4)"(1)\n"
+ PPC_LL" 5, "__stringify(STACK_FRAME_ARG3)"(1)\n"
+ PPC_LL" 4, "__stringify(STACK_FRAME_ARG2)"(1)\n"
+ PPC_LL" 3, "__stringify(STACK_FRAME_ARG1)"(1)\n"
+ PPC64_TOC_RESTORE
+" addi 1, 1, "__stringify(STACK_FRAME_SIZE)"\n"
+ PPC_FTRACE_RESTORE_LR
+" addi 1, 1, "__stringify(STACK_FRAME_MIN_SIZE)"\n"
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_FTRACE_RET
+ PPC64_TOC
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_PPC */
+
static struct ftrace_ops direct;
static int __init ftrace_direct_init(void)
diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
index ef0945670e1e..956834b0d19a 100644
--- a/samples/ftrace/ftrace-direct.c
+++ b/samples/ftrace/ftrace-direct.c
@@ -3,7 +3,7 @@
#include <linux/sched.h> /* for wake_up_process() */
#include <linux/ftrace.h>
-#ifndef CONFIG_ARM64
+#if !defined(CONFIG_ARM64) && !defined(CONFIG_PPC32)
#include <asm/asm-offsets.h>
#endif
@@ -134,6 +134,73 @@ asm (
#endif /* CONFIG_LOONGARCH */
+#ifdef CONFIG_PPC
+#include <asm/ppc_asm.h>
+
+#ifdef CONFIG_PPC64
+#define STACK_FRAME_SIZE 48
+#else
+#define STACK_FRAME_SIZE 24
+#endif
+
+#if defined(CONFIG_PPC64_ELF_ABI_V2) && !defined(CONFIG_PPC_KERNEL_PCREL)
+#define PPC64_TOC_SAVE_AND_UPDATE \
+" std 2, 24(1)\n" \
+" bcl 20, 31, 1f\n" \
+" 1: mflr 12\n" \
+" ld 2, (99f - 1b)(12)\n"
+#define PPC64_TOC_RESTORE \
+" ld 2, 24(1)\n"
+#define PPC64_TOC \
+" 99: .quad .TOC.@...base\n"
+#else
+#define PPC64_TOC_SAVE_AND_UPDATE ""
+#define PPC64_TOC_RESTORE ""
+#define PPC64_TOC ""
+#endif
+
+#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE
+#define PPC_FTRACE_RESTORE_LR \
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n" \
+" mtlr 0\n"
+#define PPC_FTRACE_RET \
+" blr\n"
+#else
+#define PPC_FTRACE_RESTORE_LR \
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n" \
+" mtctr 0\n"
+#define PPC_FTRACE_RET \
+" mtlr 0\n" \
+" bctr\n"
+#endif
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+" mflr 0\n"
+ PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_STLU" 1, -"__stringify(STACK_FRAME_SIZE)"(1)\n"
+ PPC64_TOC_SAVE_AND_UPDATE
+ PPC_STL" 3, "__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+" bl my_direct_func\n"
+ PPC_LL" 3, "__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
+ PPC64_TOC_RESTORE
+" addi 1, 1, "__stringify(STACK_FRAME_SIZE)"\n"
+ PPC_FTRACE_RESTORE_LR
+" addi 1, 1, "__stringify(STACK_FRAME_MIN_SIZE)"\n"
+ PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
+ PPC_FTRACE_RET
+ PPC64_TOC
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_PPC */
+
static struct ftrace_ops direct;
static int __init ftrace_direct_init(void)
--
2.47.0
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