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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 04/25] powerpc/ftrace: Use is_offset_in_branch_range()
Date: Sat,  7 May 2022 08:46:06 +0200	[thread overview]
Message-ID: <912ae51782f5a53c44e435497c8c3fb5cc632387.1651905939.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1651905939.git.christophe.leroy@csgroup.eu>

Use is_offset_in_branch_range() instead of create_branch()
to check if a target is within branch range.

This patch together with the previous one improves
ftrace activation time by 7%

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/trace/ftrace.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 3ce3697e8a7c..41c45b9c7f39 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -89,11 +89,9 @@ ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
  */
 static int test_24bit_addr(unsigned long ip, unsigned long addr)
 {
-	ppc_inst_t op;
 	addr = ppc_function_entry((void *)addr);
 
-	/* use the create_branch to verify that this offset can be branched */
-	return create_branch(&op, (u32 *)ip, addr, 0) == 0;
+	return is_offset_in_branch_range(addr - ip);
 }
 
 static int is_bl_op(ppc_inst_t op)
@@ -261,7 +259,6 @@ __ftrace_make_nop(struct module *mod,
 static unsigned long find_ftrace_tramp(unsigned long ip)
 {
 	int i;
-	ppc_inst_t instr;
 
 	/*
 	 * We have the compiler generated long_branch tramps at the end
@@ -270,8 +267,7 @@ static unsigned long find_ftrace_tramp(unsigned long ip)
 	for (i = NUM_FTRACE_TRAMPS - 1; i >= 0; i--)
 		if (!ftrace_tramps[i])
 			continue;
-		else if (create_branch(&instr, (void *)ip,
-				       ftrace_tramps[i], 0) == 0)
+		else if (is_offset_in_branch_range(ftrace_tramps[i] - ip))
 			return ftrace_tramps[i];
 
 	return 0;
-- 
2.35.1


  parent reply	other threads:[~2022-05-07  6:48 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 ` Christophe Leroy [this message]
2022-05-07  6:46 ` [PATCH v2 05/25] powerpc/code-patching: Inline create_branch() Christophe Leroy
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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