From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
naveen.n.rao@linux.vnet.ibm.com
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>,
linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v2 05/25] powerpc/code-patching: Inline create_branch()
Date: Sat, 7 May 2022 08:46:07 +0200 [thread overview]
Message-ID: <69851cc9a7bf8f03d025e6d29e165f2d0bd3bb6e.1651905939.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1651905939.git.christophe.leroy@csgroup.eu>
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
next prev parent reply other threads:[~2022-05-07 6:47 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-07 6:46 [PATCH v2 00/25] powerpc: ftrace optimisation and cleanup and more [v2] Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 01/25] powerpc/ftrace: Refactor prepare_ftrace_return() Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 02/25] powerpc/ftrace: Remove redundant create_branch() calls Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 03/25] powerpc/code-patching: Inline is_offset_in_{cond}_branch_range() Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 04/25] powerpc/ftrace: Use is_offset_in_branch_range() Christophe Leroy
2022-05-07 6:46 ` Christophe Leroy [this message]
2022-05-07 6:46 ` [PATCH v2 06/25] powerpc/ftrace: Inline ftrace_modify_code() Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 07/25] powerpc/ftrace: Use patch_instruction() return directly Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 08/25] powerpc: Add CONFIG_PPC64_ELF_ABI_V1 and CONFIG_PPC64_ELF_ABI_V2 Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 09/25] powerpc: Replace PPC64_ELF_ABI_v{1/2} by CONFIG_PPC64_ELF_ABI_V{1/2} Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 10/25] powerpc: Finalise cleanup around ABI use Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 11/25] powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64 Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 12/25] powerpc/ftrace: Don't include ftrace.o for CONFIG_FTRACE_SYSCALLS Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 13/25] powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of CONFIG_DYNAMIC_FTRACE Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 14/25] powerpc/ftrace: Remove ftrace_plt_tramps[] Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 15/25] powerpc/ftrace: Use BRANCH_SET_LINK instead of value 1 Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 16/25] powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 17/25] powerpc/ftrace: Use size macro " Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 18/25] powerpc/ftrace: Simplify expected_nop_sequence() Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 19/25] powerpc/ftrace: Minimise number of #ifdefs Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 20/25] powerpc/inst: Add __copy_inst_from_kernel_nofault() Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 21/25] powerpc/ftrace: Don't use copy_from_kernel_nofault() in module_trampoline_target() Christophe Leroy
2022-05-07 11:29 ` kernel test robot
2022-05-07 6:46 ` [PATCH v2 22/25] powerpc/inst: Remove PPC_INST_BRANCH Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 23/25] powerpc/modules: Use PPC_LI macros instead of opencoding Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 24/25] powerpc/inst: Remove PPC_INST_BL Christophe Leroy
2022-05-07 6:46 ` [PATCH v2 25/25] powerpc/opcodes: Remove unused PPC_INST_XXX macros Christophe Leroy
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