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 35D13C77B7D for ; Thu, 18 May 2023 13:16:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231591AbjERNQH (ORCPT ); Thu, 18 May 2023 09:16:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231701AbjERNPr (ORCPT ); Thu, 18 May 2023 09:15:47 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE95C1735; Thu, 18 May 2023 06:15:12 -0700 (PDT) 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 8015264F46; Thu, 18 May 2023 13:14:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97AA5C433A8; Thu, 18 May 2023 13:13:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684415640; bh=1Q2OacXMgaOE1GaE82tcNP9mKmi++bzDbv1pyxwUhQs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E58RuOsyjDm0MSwqlPq2VfQw6WjfUgQVPzQemHtJ/mDL9a2shJvWKDryIjGnpK05X keC8NjhdHnpy5I71eEfiJMFTPpQ9k5iHl3josQCI8r9MZd8+adNza+aDLARO/5KGe9 dfE1rnK/7jCAE14U89IFb5B2/CfJWk2VmHkFbSFBjUh2RrwjpzbTp6U2XVScSw7FU2 6kroejxVAfIp7cjFoeQUkSdcjdkCbm3o09VBhCychkxxAxmdcZEIVz+GbgrEWHJyZi lMVRCRRErqxFb1hO5UmUj+ne/WYlU1JkFaxd1vrwKijk1neFq97kvrWVhX0neSaJ7D PBW6h3qYogesg== From: guoren@kernel.org To: arnd@arndb.de, guoren@kernel.org, palmer@rivosinc.com, tglx@linutronix.de, peterz@infradead.org, luto@kernel.org, conor.dooley@microchip.com, heiko@sntech.de, jszhang@kernel.org, chenhuacai@kernel.org, apatel@ventanamicro.com, atishp@atishpatra.org, mark.rutland@arm.com, bjorn@kernel.org, paul.walmsley@sifive.com, catalin.marinas@arm.com, will@kernel.org, rppt@kernel.org, anup@brainfault.org, shihua@iscas.ac.cn, jiawei@iscas.ac.cn, liweiwei@iscas.ac.cn, luxufan@iscas.ac.cn, chunyu@iscas.ac.cn, tsu.yubo@gmail.com, wefu@redhat.com, wangjunqiang@iscas.ac.cn, kito.cheng@sifive.com, andy.chiu@sifive.com, vincent.chen@sifive.com, greentime.hu@sifive.com, corbet@lwn.net, wuwei2016@iscas.ac.cn, jrtc27@jrtc27.com Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Guo Ren Subject: [RFC PATCH 17/22] riscv: s64ilp32: Implement cmpxchg_double Date: Thu, 18 May 2023 09:10:08 -0400 Message-Id: <20230518131013.3366406-18-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20230518131013.3366406-1-guoren@kernel.org> References: <20230518131013.3366406-1-guoren@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org From: Guo Ren The s64ilp32 has the ability to exclusively load and store (ld/sd) a pair of words from an address. Then the SLUB can take advantage of a cmpxchg_double implementation to avoid taking some locks. This patch provides an implementation of cmpxchg_double for 64-bit pairs, and activates the logic required for the SLUB to use these functions (HAVE_ALIGNED_STRUCT_PAGE and HAVE_CMPXCHG_DOUBLE). Similar commit: 5284e1b4bc8a ("arm64: xchg: Implement cmpxchg_double") Signed-off-by: Guo Ren Signed-off-by: Guo Ren --- arch/riscv/Kconfig | 2 ++ arch/riscv/include/asm/cmpxchg.h | 53 ++++++++++++++++++++++++++++++++ 2 files changed, 55 insertions(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index e0c3dee68510..51853f883fc5 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -78,6 +78,7 @@ config RISCV select GENERIC_TIME_VSYSCALL if MMU select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO select HARDIRQS_SW_RESEND + select HAVE_ALIGNED_STRUCT_PAGE if SLUB && ARCH_RV64ILP32 select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL @@ -96,6 +97,7 @@ config RISCV select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU select HAVE_ARCH_VMAP_STACK if MMU && 64BIT select HAVE_ASM_MODVERSIONS + select HAVE_CMPXCHG_DOUBLE if ARCH_RV64ILP32 select HAVE_CONTEXT_TRACKING_USER select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_CONTIGUOUS if MMU diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h index 12debce235e5..808730d151e7 100644 --- a/arch/riscv/include/asm/cmpxchg.h +++ b/arch/riscv/include/asm/cmpxchg.h @@ -7,6 +7,7 @@ #define _ASM_RISCV_CMPXCHG_H #include +#include #include #include @@ -360,4 +361,56 @@ arch_cmpxchg_relaxed((ptr), (o), (n)); \ }) +#ifdef CONFIG_ARCH_RV64ILP32 +#define system_has_cmpxchg_double() 1 + +#define __cmpxchg_double_check(ptr1, ptr2) \ +({ \ + if (sizeof(*(ptr1)) != 4) \ + BUILD_BUG(); \ + if (sizeof(*(ptr2)) != 4) \ + BUILD_BUG(); \ + VM_BUG_ON((ulong *)(ptr2) - (ulong *)(ptr1) != 1); \ + VM_BUG_ON(((ulong)ptr1 & 0x7) != 0); \ +}) + +#define __cmpxchg_double(old1, old2, new1, new2, ptr) \ +({ \ + __typeof__(ptr) __ptr = (ptr); \ + register unsigned int __ret; \ + u64 __old; \ + u64 __new; \ + u64 __tmp; \ + switch (sizeof(*(ptr))) { \ + case 4: \ + __old = ((u64)old2 << 32) | (u64)old1; \ + __new = ((u64)new2 << 32) | (u64)new1; \ + __asm__ __volatile__ ( \ + "0: lr.d %0, %2\n" \ + " bne %0, %z3, 1f\n" \ + " sc.d %1, %z4, %2\n" \ + " bnez %1, 0b\n" \ + "1:\n" \ + : "=&r" (__tmp), "=&r" (__ret), "+A" (*__ptr) \ + : "rJ" (__old), "rJ" (__new) \ + : "memory"); \ + __ret = (__old == __tmp); \ + break; \ + default: \ + BUILD_BUG(); \ + } \ + __ret; \ +}) + +#define arch_cmpxchg_double(ptr1, ptr2, o1, o2, n1, n2) \ +({ \ + int __ret; \ + __cmpxchg_double_check(ptr1, ptr2); \ + __ret = __cmpxchg_double((ulong)(o1), (ulong)(o2), \ + (ulong)(n1), (ulong)(n2), \ + ptr1); \ + __ret; \ +}) +#endif + #endif /* _ASM_RISCV_CMPXCHG_H */ -- 2.36.1