From mboxrd@z Thu Jan 1 00:00:00 1970 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34B69CCA483 for ; Tue, 7 Jun 2022 14:31:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245519AbiFGObe (ORCPT ); Tue, 7 Jun 2022 10:31:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244411AbiFGObc (ORCPT ); Tue, 7 Jun 2022 10:31:32 -0400 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17A6FD106 for ; Tue, 7 Jun 2022 07:31:29 -0700 (PDT) Received: from ip5b412258.dynamic.kabel-deutschland.de ([91.65.34.88] helo=phil.lan) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1nyaEv-0008Ra-ME; Tue, 07 Jun 2022 16:31:25 +0200 From: Heiko Stuebner To: palmer@dabbelt.com, paul.walmsley@sifive.com Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, wefu@redhat.com, guoren@kernel.org, mick@ics.forth.gr, samuel@sholland.org, cmuellner@linux.com, philipp.tomsich@vrull.eu, hch@lst.de, Heiko Stuebner Subject: [PATCH 1/2] riscv: introduce nops and __nops macros for NOP sequences Date: Tue, 7 Jun 2022 16:30:58 +0200 Message-Id: <20220607143059.1054074-2-heiko@sntech.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220607143059.1054074-1-heiko@sntech.de> References: <20220607143059.1054074-1-heiko@sntech.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org NOP sequences tend to get used for padding out alternative sections This change adds macros for generating these sequences as both inline asm blocks, but also as strings suitable for embedding in other asm blocks directly. It essentially mimics similar functionality from arm64 introduced by Wil Deacon in commit f99a250cb6a3 ("arm64: barriers: introduce nops and __nops macros for NOP sequences"). Signed-off-by: Heiko Stuebner --- arch/riscv/include/asm/asm.h | 15 +++++++++++++++ arch/riscv/include/asm/barrier.h | 2 ++ 2 files changed, 17 insertions(+) diff --git a/arch/riscv/include/asm/asm.h b/arch/riscv/include/asm/asm.h index 618d7c5af1a2..1b471ff73178 100644 --- a/arch/riscv/include/asm/asm.h +++ b/arch/riscv/include/asm/asm.h @@ -67,4 +67,19 @@ #error "Unexpected __SIZEOF_SHORT__" #endif +#ifdef __ASSEMBLY__ + +/* Common assembly source macros */ + +/* + * NOP sequence + */ +.macro nops, num + .rept \num + nop + .endr +.endm + +#endif /* __ASSEMBLY__ */ + #endif /* _ASM_RISCV_ASM_H */ diff --git a/arch/riscv/include/asm/barrier.h b/arch/riscv/include/asm/barrier.h index d0e24aaa2aa0..110752594228 100644 --- a/arch/riscv/include/asm/barrier.h +++ b/arch/riscv/include/asm/barrier.h @@ -13,6 +13,8 @@ #ifndef __ASSEMBLY__ #define nop() __asm__ __volatile__ ("nop") +#define __nops(n) ".rept " #n "\nnop\n.endr\n" +#define nops(n) __asm__ __volatile__ (__nops(n)) #define RISCV_FENCE(p, s) \ __asm__ __volatile__ ("fence " #p "," #s : : : "memory") -- 2.35.1