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 5FC6FC636CD for ; Tue, 7 Feb 2023 08:01:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229831AbjBGIB3 (ORCPT ); Tue, 7 Feb 2023 03:01:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229656AbjBGIB2 (ORCPT ); Tue, 7 Feb 2023 03:01:28 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E21B367CA for ; Tue, 7 Feb 2023 00:01:13 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 2AF0F61204 for ; Tue, 7 Feb 2023 08:01:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20237C433D2; Tue, 7 Feb 2023 08:01:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675756872; bh=x0R8KhTLUoO8CkejbGXYa3ImxphYEkMChMOeIENOy9o=; h=Subject:To:Cc:From:Date:From; b=O6X5kDd3GfHM9R5fQzzP997LWggfmUlhTH5fj4mvBhCgGAgJBKtOUsLWJOd2QtpwB adDQhDLIaDdTP3XACo2TTdMY9rqoqtiEEiG28+TUpQ8La+dYcWxEW3eQ30gn8CKjVc qF4+FVleFE2Frps9Of3rqgfCdRB0D15gfitHX974= Subject: FAILED: patch "[PATCH] riscv: Fix build with CONFIG_CC_OPTIMIZE_FOR_SIZE=y" failed to apply to 6.1-stable tree To: samuel@sholland.org, conor.dooley@microchip.com, palmer@rivosinc.com Cc: From: Date: Tue, 07 Feb 2023 09:01:09 +0100 Message-ID: <167575686919491@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . Possible dependencies: 0b1d60d6dd9e ("riscv: Fix build with CONFIG_CC_OPTIMIZE_FOR_SIZE=y") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 0b1d60d6dd9e2e867cc6e4277d73ea5a7ff2d4d0 Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Thu, 22 Sep 2022 01:09:58 -0500 Subject: [PATCH] riscv: Fix build with CONFIG_CC_OPTIMIZE_FOR_SIZE=y commit 8eb060e10185 ("arch/riscv: add Zihintpause support") broke building with CONFIG_CC_OPTIMIZE_FOR_SIZE enabled (gcc 11.1.0): CC arch/riscv/kernel/vdso/vgettimeofday.o In file included from : ./arch/riscv/include/asm/jump_label.h: In function 'cpu_relax': ././include/linux/compiler_types.h:285:33: warning: 'asm' operand 0 probably does not match constraints 285 | #define asm_volatile_goto(x...) asm goto(x) | ^~~ ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro 'asm_volatile_goto' 41 | asm_volatile_goto( | ^~~~~~~~~~~~~~~~~ ././include/linux/compiler_types.h:285:33: error: impossible constraint in 'asm' 285 | #define asm_volatile_goto(x...) asm goto(x) | ^~~ ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro 'asm_volatile_goto' 41 | asm_volatile_goto( | ^~~~~~~~~~~~~~~~~ make[1]: *** [scripts/Makefile.build:249: arch/riscv/kernel/vdso/vgettimeofday.o] Error 1 make: *** [arch/riscv/Makefile:128: vdso_prepare] Error 2 Having a static branch in cpu_relax() is problematic because that function is widely inlined, including in some quite complex functions like in the VDSO. A quick measurement shows this static branch is responsible by itself for around 40% of the jump table. Drop the static branch, which ends up being the same number of instructions anyway. If Zihintpause is supported, we trade the nop from the static branch for a div. If Zihintpause is unsupported, we trade the jump from the static branch for (what gets interpreted as) a nop. Fixes: 8eb060e10185 ("arch/riscv: add Zihintpause support") Signed-off-by: Samuel Holland Reviewed-by: Conor Dooley Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index 3c8a5ca95c72..3bf10a8e665a 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -67,7 +67,6 @@ enum riscv_isa_ext_id { */ enum riscv_isa_ext_key { RISCV_ISA_EXT_KEY_FPU, /* For 'F' and 'D' */ - RISCV_ISA_EXT_KEY_ZIHINTPAUSE, RISCV_ISA_EXT_KEY_MAX, }; @@ -87,8 +86,6 @@ static __always_inline int riscv_isa_ext2key(int num) return RISCV_ISA_EXT_KEY_FPU; case RISCV_ISA_EXT_d: return RISCV_ISA_EXT_KEY_FPU; - case RISCV_ISA_EXT_ZIHINTPAUSE: - return RISCV_ISA_EXT_KEY_ZIHINTPAUSE; default: return -EINVAL; } diff --git a/arch/riscv/include/asm/vdso/processor.h b/arch/riscv/include/asm/vdso/processor.h index 1e4f8b4aef79..789bdb8211a2 100644 --- a/arch/riscv/include/asm/vdso/processor.h +++ b/arch/riscv/include/asm/vdso/processor.h @@ -4,30 +4,25 @@ #ifndef __ASSEMBLY__ -#include #include -#include static inline void cpu_relax(void) { - if (!static_branch_likely(&riscv_isa_ext_keys[RISCV_ISA_EXT_KEY_ZIHINTPAUSE])) { #ifdef __riscv_muldiv - int dummy; - /* In lieu of a halt instruction, induce a long-latency stall. */ - __asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy)); + int dummy; + /* In lieu of a halt instruction, induce a long-latency stall. */ + __asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy)); #endif - } else { - /* - * Reduce instruction retirement. - * This assumes the PC changes. - */ + /* + * Reduce instruction retirement. + * This assumes the PC changes. + */ #ifdef __riscv_zihintpause - __asm__ __volatile__ ("pause"); + __asm__ __volatile__ ("pause"); #else - /* Encoding of the pause instruction */ - __asm__ __volatile__ (".4byte 0x100000F"); + /* Encoding of the pause instruction */ + __asm__ __volatile__ (".4byte 0x100000F"); #endif - } barrier(); }