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From: Hari Bathini <hbathini@linux.ibm.com>
To: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
	linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Michael Ellerman <mpe@ellerman.id.au>,
	"Naveen N. Rao" <naveen@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Nicholas Piggin <npiggin@gmail.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Andrii Nakryiko <andrii@kernel.org>,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	Vishal Chourasia <vishalc@linux.ibm.com>,
	Mahesh J Salgaonkar <mahesh@linux.ibm.com>
Subject: [PATCH v6 16/17] samples/ftrace: Add support for ftrace direct samples on powerpc
Date: Fri, 18 Oct 2024 23:06:31 +0530	[thread overview]
Message-ID: <20241018173632.277333-17-hbathini@linux.ibm.com> (raw)
In-Reply-To: <20241018173632.277333-1-hbathini@linux.ibm.com>

From: Naveen N Rao <naveen@kernel.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@kernel.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.@tocbase\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.@tocbase\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.@tocbase\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.@tocbase\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.@tocbase\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


  parent reply	other threads:[~2024-10-18 17:38 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-18 17:36 [PATCH v6 00/17] powerpc: Core ftrace rework, support for ftrace direct and bpf trampolines Hari Bathini
2024-10-18 17:36 ` [PATCH v6 01/17] powerpc/trace: Account for -fpatchable-function-entry support by toolchain Hari Bathini
2024-10-18 17:36 ` [PATCH v6 02/17] powerpc/kprobes: Use ftrace to determine if a probe is at function entry Hari Bathini
2024-10-18 17:36 ` [PATCH v6 03/17] powerpc64/ftrace: Nop out additional 'std' instruction emitted by gcc v5.x Hari Bathini
2024-10-18 17:36 ` [PATCH v6 04/17] powerpc32/ftrace: Unify 32-bit and 64-bit ftrace entry code Hari Bathini
2024-10-18 17:36 ` [PATCH v6 05/17] powerpc/module_64: Convert #ifdef to IS_ENABLED() Hari Bathini
2024-10-18 17:36 ` [PATCH v6 06/17] powerpc/ftrace: Remove pointer to struct module from dyn_arch_ftrace Hari Bathini
2024-10-18 17:36 ` [PATCH v6 07/17] powerpc/ftrace: Skip instruction patching if the instructions are the same Hari Bathini
2024-10-18 17:36 ` [PATCH v6 08/17] powerpc/ftrace: Move ftrace stub used for init text before _einittext Hari Bathini
2024-10-18 17:36 ` [PATCH v6 09/17] powerpc64/bpf: Fold bpf_jit_emit_func_call_hlp() into bpf_jit_emit_func_call_rel() Hari Bathini
2024-10-18 17:36 ` [PATCH v6 10/17] powerpc/ftrace: Add a postlink script to validate function tracer Hari Bathini
2024-10-18 17:36 ` [PATCH v6 11/17] kbuild: Add generic hook for architectures to use before the final vmlinux link Hari Bathini
2024-10-27  9:14   ` Masahiro Yamada
2024-10-18 17:36 ` [PATCH v6 12/17] powerpc64/ftrace: Move ftrace sequence out of line Hari Bathini
2024-10-27  9:21   ` Masahiro Yamada
2024-10-18 17:36 ` [PATCH v6 13/17] powerpc64/ftrace: Support .text larger than 32MB with out-of-line stubs Hari Bathini
2024-10-27  9:17   ` Masahiro Yamada
2024-10-18 17:36 ` [PATCH v6 14/17] powerpc/ftrace: Add support for DYNAMIC_FTRACE_WITH_CALL_OPS Hari Bathini
2024-10-18 17:36 ` [PATCH v6 15/17] powerpc/ftrace: Add support for DYNAMIC_FTRACE_WITH_DIRECT_CALLS Hari Bathini
2024-10-18 17:36 ` Hari Bathini [this message]
2024-10-18 17:36 ` [PATCH v6 17/17] powerpc64/bpf: Add support for bpf trampolines Hari Bathini
2024-10-28  2:23   ` Michael Ellerman
2024-10-29  6:44     ` Hari Bathini

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