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From:   Christophe Leroy <christophe.leroy@csgroup.eu>
To:     "Naveen N . Rao" <naveen.n.rao@linux.vnet.ibm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>
Cc:     Christophe Leroy <christophe.leroy@csgroup.eu>,
        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v1 05/22] powerpc/code-patching: Inline create_branch()
Date:   Thu, 24 Mar 2022 15:29:55 +0100
Message-Id: <2b0c4291fbf2e467fbae9c504bf671bfc29df70a.1648131740.git.christophe.leroy@csgroup.eu>
In-Reply-To: <cover.1648131740.git.christophe.leroy@csgroup.eu>
References: <cover.1648131740.git.christophe.leroy@csgroup.eu>
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create_branch() is a good candidate for inlining because:
- Flags can be folded in.
- Range tests are likely to be already done.

Hence reducing the create_branch() to only a set of instructions.

So inline it.

It improves ftrace activation by 10%.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/code-patching.h | 22 ++++++++++++++++++++--
 arch/powerpc/lib/code-patching.c         | 20 --------------------
 2 files changed, 20 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
index e7c5df50cb4e..4260e89f62b1 100644
--- a/arch/powerpc/include/asm/code-patching.h
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -49,8 +49,26 @@ static inline bool is_offset_in_cond_branch_range(long offset)
 	return offset >= -0x8000 && offset <= 0x7fff && !(offset & 0x3);
 }
 
-int create_branch(ppc_inst_t *instr, const u32 *addr,
-		  unsigned long target, int flags);
+static inline int create_branch(ppc_inst_t *instr, const u32 *addr,
+				unsigned long target, int flags)
+{
+	long offset;
+
+	*instr = ppc_inst(0);
+	offset = target;
+	if (! (flags & BRANCH_ABSOLUTE))
+		offset = offset - (unsigned long)addr;
+
+	/* Check we can represent the target in the instruction format */
+	if (!is_offset_in_branch_range(offset))
+		return 1;
+
+	/* Mask out the flags and target, so they don't step on each other. */
+	*instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC));
+
+	return 0;
+}
+
 int create_cond_branch(ppc_inst_t *instr, const u32 *addr,
 		       unsigned long target, int flags);
 int patch_branch(u32 *addr, unsigned long target, int flags);
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 58262c7e447c..7adbdb05fee7 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -230,26 +230,6 @@ bool is_conditional_branch(ppc_inst_t instr)
 }
 NOKPROBE_SYMBOL(is_conditional_branch);
 
-int create_branch(ppc_inst_t *instr, const u32 *addr,
-		  unsigned long target, int flags)
-{
-	long offset;
-
-	*instr = ppc_inst(0);
-	offset = target;
-	if (! (flags & BRANCH_ABSOLUTE))
-		offset = offset - (unsigned long)addr;
-
-	/* Check we can represent the target in the instruction format */
-	if (!is_offset_in_branch_range(offset))
-		return 1;
-
-	/* Mask out the flags and target, so they don't step on each other. */
-	*instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC));
-
-	return 0;
-}
-
 int create_cond_branch(ppc_inst_t *instr, const u32 *addr,
 		       unsigned long target, int flags)
 {
-- 
2.35.1