From patchwork Wed Nov 23 15:39:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guo Ren X-Patchwork-Id: 13053957 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 66AABC433FE for ; Wed, 23 Nov 2022 16:46:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=hyKHys7CJ+E/XNSeLqo7kUI5lVtm0y8opQTqTckBQcQ=; b=iR3znoKppvwRO/ jFLaLsq9KUSGGl0DN08+xdQXks3pRdZt4V7OyUazpR3w03VJTNDHhjh9dfkns/omC38knxS1OOlTm bKtJKY4lmEd4nQ4byxSrEK3zzJSixYTV/wYofhpWxHNJ+/XWlP1XqsGsVGOwRfR3JXPgJr4SiW3Gp PM+r10qt8IapIT9VTtaw4du7Edr58SpfzqWd6/ORi2iJGZBxlGAYwR+qE9kwljjNnvpGHLuUvZApq 3uSi2EC50qzpUZojj/SkjbJix021NE81+JMML5xdFuA8gbVlQJS9+w/HCh0JVXPw6vaGhzxkBv8Aq F9Kplg3iMaIJrljjERKg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oxssx-000xZa-FE; Wed, 23 Nov 2022 16:46:07 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oxrrF-000X1d-Q4 for linux-riscv@lists.infradead.org; Wed, 23 Nov 2022 15:40:19 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 4CF06B82141; Wed, 23 Nov 2022 15:40:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F281C433C1; Wed, 23 Nov 2022 15:40:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669218015; bh=K44IU5zSr+xRSYeCBFFHSvlbL/P6QS9pgaMT4XAkl6o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vRSCEWckR+qyWbBwXdDb1HYy7iZFIr/KBzkURDpS8Px1CDdbR6wes8ltwnXbGCEm5 wy/VDWMU1S/B1GT1t8GP78yB1Blh8+svK3vMGbH96vKxRK5wBmRwl8KP9NuHQStdkx OvVaDH/8Qv+VTG6Lm3PMgjurnElt7HTx+5SoV9+Axrxou5ocuOFQ7tJW62xGrHxrzr 8NhwJ6NFw/CgeJgzMJsviFaLo48Rv7Ild9yInafyfBP9gdvvU3ItR4L81D6fyhpHwY zkcnpvfxvQK8QJeGDVtIhcDktiq31DSJ+8dlyukYet2l6DDuDOwMiDAucwyFQwZd2Q b+242c6ae8lKA== From: guoren@kernel.org To: anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, conor.dooley@microchip.com, heiko@sntech.de, rostedt@goodmis.org, mhiramat@kernel.org, jolsa@redhat.com, bp@suse.de, jpoimboe@kernel.org, suagrfillet@gmail.com, andy.chiu@sifive.com Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Guo Ren , Guo Ren Subject: [PATCH V3 2/5] riscv: ftrace: Remove wasted nops for !RISCV_ISA_C Date: Wed, 23 Nov 2022 10:39:47 -0500 Message-Id: <20221123153950.2911981-3-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20221123153950.2911981-1-guoren@kernel.org> References: <20221123153950.2911981-1-guoren@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221123_074018_099348_922CD378 X-CRM114-Status: UNSURE ( 7.79 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Guo Ren When CONFIG_RISCV_ISA_C=n, -fpatchable-function-entry=8 would generate more nops than we expect. Because it treat nop opcode as 0x00000013 instead of 0x0001. Dump of assembler code for function dw_pcie_free_msi: 0xffffffff806fce94 <+0>: sd ra,-8(sp) 0xffffffff806fce98 <+4>: auipc ra,0xff90f 0xffffffff806fce9c <+8>: jalr -684(ra) # 0xffffffff8000bbec 0xffffffff806fcea0 <+12>: ld ra,-8(sp) 0xffffffff806fcea4 <+16>: nop /* wasted */ 0xffffffff806fcea8 <+20>: nop /* wasted */ 0xffffffff806fceac <+24>: nop /* wasted */ 0xffffffff806fceb0 <+28>: nop /* wasted */ 0xffffffff806fceb4 <+0>: addi sp,sp,-48 0xffffffff806fceb8 <+4>: sd s0,32(sp) 0xffffffff806fcebc <+8>: sd s1,24(sp) 0xffffffff806fcec0 <+12>: sd s2,16(sp) 0xffffffff806fcec4 <+16>: sd s3,8(sp) 0xffffffff806fcec8 <+20>: sd ra,40(sp) 0xffffffff806fcecc <+24>: addi s0,sp,48 Signed-off-by: Guo Ren Signed-off-by: Guo Ren --- arch/riscv/Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 1c8ec656e916..36cc609c5d03 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -11,7 +11,11 @@ LDFLAGS_vmlinux := ifeq ($(CONFIG_DYNAMIC_FTRACE),y) LDFLAGS_vmlinux := --no-relax KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY +ifeq ($(CONFIG_RISCV_ISA_C),y) CC_FLAGS_FTRACE := -fpatchable-function-entry=8 +else + CC_FLAGS_FTRACE := -fpatchable-function-entry=4 +endif endif ifeq ($(CONFIG_CMODEL_MEDLOW),y)