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From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Paul Mackerras <paulus@samba.org>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v3 19/25] powerpc/ftrace: Minimise number of #ifdefs
Date: Wed, 18 May 2022 15:15:40 +0530	[thread overview]
Message-ID: <1652866821.cdcfe8bs78.naveen@linux.ibm.com> (raw)
In-Reply-To: <18ce6708d6f8c71d87436f9c6019f04df4125128.1652074503.git.christophe.leroy@csgroup.eu>

Christophe Leroy wrote:
> A lot of #ifdefs can be replaced by IS_ENABLED()
> 
> Do so.
> 
> This requires to have kernel_toc_addr() defined at all time
> as well as PPC_INST_LD_TOC and PPC_INST_STD_LR.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> v2: Moved the setup of pop outside of the big if()/else() in __ftrace_make_nop()
> ---
>  arch/powerpc/include/asm/code-patching.h |   2 -
>  arch/powerpc/include/asm/module.h        |   2 -
>  arch/powerpc/include/asm/sections.h      |  24 +--
>  arch/powerpc/kernel/trace/ftrace.c       | 182 +++++++++++------------
>  4 files changed, 103 insertions(+), 107 deletions(-)
> 

<snip>

> @@ -710,6 +707,9 @@ void arch_ftrace_update_code(int command)
> 
>  #ifdef CONFIG_PPC64
>  #define PACATOC offsetof(struct paca_struct, kernel_toc)
> +#else
> +#define PACATOC 0
> +#endif

This conflicts with my fix for the ftrace init tramp:
https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20220516071422.463738-1-naveen.n.rao@linux.vnet.ibm.com/

It probably makes sense to retain #ifdef CONFIG_PPC64, so that we can 
get rid of the PACATOC. Here is an incremental diff:

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index da1a2f8ebb72f3..28169a1ccc7377 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -701,11 +701,6 @@ void arch_ftrace_update_code(int command)
 }
 
 #ifdef CONFIG_PPC64
-#define PACATOC offsetof(struct paca_struct, kernel_toc)
-#else
-#define PACATOC 0
-#endif
-
 extern unsigned int ftrace_tramp_text[], ftrace_tramp_init[];
 
 void ftrace_free_init_tramp(void)
@@ -724,7 +719,7 @@ int __init ftrace_dyn_arch_init(void)
 	int i;
 	unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init };
 	u32 stub_insns[] = {
-		PPC_RAW_LD(_R12, _R13, PACATOC),
+		PPC_RAW_LD(_R12, _R13, offsetof(struct paca_struct, kernel_toc)),
 		PPC_RAW_ADDIS(_R12, _R12, 0),
 		PPC_RAW_ADDI(_R12, _R12, 0),
 		PPC_RAW_MTCTR(_R12),
@@ -733,9 +728,6 @@ int __init ftrace_dyn_arch_init(void)
 	unsigned long addr;
 	long reladdr;
 
-	if (IS_ENABLED(CONFIG_PPC32))
-		return 0;
-
 	addr = ppc_global_function_entry((void *)FTRACE_REGS_ADDR);
 	reladdr = addr - kernel_toc_addr();
 
@@ -754,6 +746,7 @@ int __init ftrace_dyn_arch_init(void)
 
 	return 0;
 }
+#endif
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 

- Naveen

  reply	other threads:[~2022-05-18  9:46 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-09  5:35 [PATCH v3 00/25] powerpc: ftrace optimisation and cleanup and more [v3] Christophe Leroy
2022-05-09  5:35 ` [PATCH v3 01/25] powerpc/ftrace: Refactor prepare_ftrace_return() Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 02/25] powerpc/ftrace: Remove redundant create_branch() calls Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 03/25] powerpc/code-patching: Inline is_offset_in_{cond}_branch_range() Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 04/25] powerpc/ftrace: Use is_offset_in_branch_range() Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 05/25] powerpc/code-patching: Inline create_branch() Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 06/25] powerpc/ftrace: Inline ftrace_modify_code() Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 07/25] powerpc/ftrace: Use patch_instruction() return directly Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 08/25] powerpc: Add CONFIG_PPC64_ELF_ABI_V1 and CONFIG_PPC64_ELF_ABI_V2 Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 09/25] powerpc: Replace PPC64_ELF_ABI_v{1/2} by CONFIG_PPC64_ELF_ABI_V{1/2} Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 10/25] powerpc: Finalise cleanup around ABI use Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 11/25] powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64 Christophe Leroy
2022-08-08 18:47   ` Nick Desaulniers
2022-08-09  6:25     ` Naveen N. Rao
2022-05-09  5:36 ` [PATCH v3 12/25] powerpc/ftrace: Don't include ftrace.o for CONFIG_FTRACE_SYSCALLS Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 13/25] powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of CONFIG_DYNAMIC_FTRACE Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 14/25] powerpc/ftrace: Remove ftrace_plt_tramps[] Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 15/25] powerpc/ftrace: Use BRANCH_SET_LINK instead of value 1 Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 16/25] powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 17/25] powerpc/ftrace: Use size macro " Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 18/25] powerpc/ftrace: Simplify expected_nop_sequence() Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 19/25] powerpc/ftrace: Minimise number of #ifdefs Christophe Leroy
2022-05-18  9:45   ` Naveen N. Rao [this message]
2022-05-18 10:08     ` Christophe Leroy
2022-05-18 11:19     ` Michael Ellerman
2022-05-18 12:03       ` Michael Ellerman
2022-05-18 12:12         ` Christophe Leroy
2022-05-18 17:03           ` Naveen N. Rao
2022-05-18 12:04       ` Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 20/25] powerpc/inst: Add __copy_inst_from_kernel_nofault() Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 21/25] powerpc/ftrace: Don't use copy_from_kernel_nofault() in module_trampoline_target() Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 22/25] powerpc/inst: Remove PPC_INST_BRANCH Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 23/25] powerpc/modules: Use PPC_LI macros instead of opencoding Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 24/25] powerpc/inst: Remove PPC_INST_BL Christophe Leroy
2022-05-09  5:36 ` [PATCH v3 25/25] powerpc/opcodes: Remove unused PPC_INST_XXX macros Christophe Leroy
2022-05-24 11:09 ` [PATCH v3 00/25] powerpc: ftrace optimisation and cleanup and more [v3] Michael Ellerman

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