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 D330BC433FE for ; Sun, 24 Apr 2022 07:30:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238519AbiDXHc5 (ORCPT ); Sun, 24 Apr 2022 03:32:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238489AbiDXHcs (ORCPT ); Sun, 24 Apr 2022 03:32:48 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E770F151F4B; Sun, 24 Apr 2022 00:29:47 -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 2F19861305; Sun, 24 Apr 2022 07:29:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DAC45C385AC; Sun, 24 Apr 2022 07:29:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1650785386; bh=FQV8N0eLk4AtQ1VH8mq3+se93l+0KbFwvJtFQphXmxE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LSeeL9QRrlImtNcEzsT/DeqqmU+ixGcecS4w8gnug0ve9xyoL1qgfv+S54+86tC/7 jU/sx1b+27bi6lhpl5XZ8iUYHYb5THPqdqfCVRH8IB72bwamebNAxWkf4yGUUmkR8R LD4a6yD8ukXt1I55I0Ih5+CUx39GAsAjOT++bfuho6kPTzV5e5XCLrwigFnclnqssD 3snud2iqCV/shdF/F8QhieWIZrcxxgHLl8Q2tcCS2UuDbgCTZHhA/mBCvpGcn1vh0l lpfQO4ayZw714G4stlGT6EjcBPbYlxiHt9sJRep7zy03vZP/q6HLx4V0stRVcaWw+8 Gnom9vN0SfzsA== From: guoren@kernel.org To: guoren@kernel.org, arnd@arndb.de, mark.rutland@arm.com, boqun.feng@gmail.com, peterz@infradead.org, will@kernel.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, Guo Ren Subject: [PATCH V4 2/3] csky: atomic: Add custom atomic.h implementation Date: Sun, 24 Apr 2022 15:29:17 +0800 Message-Id: <20220424072918.2596899-3-guoren@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220424072918.2596899-1-guoren@kernel.org> References: <20220424072918.2596899-1-guoren@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Guo Ren The generic atomic.h used cmpxchg to implement the atomic operations, it will cause daul loop to reduce the forward guarantee. The patch implement csky custom atomic operations with ldex/stex instructions for the best performance. Important comment by Rutland: 8e86f0b409a4 ("arm64: atomics: fix use of acquire + release for full barrier semantics") Link: https://lore.kernel.org/linux-riscv/CAJF2gTSAxpAi=LbAdu7jntZRUa=-dJwL0VfmDfBV5MHB=rcZ-w@mail.gmail.com/T/#m27a0f1342995deae49ce1d0e1f2683f8a181d6c3 Signed-off-by: Guo Ren Signed-off-by: Guo Ren Cc: Mark Rutland --- arch/csky/include/asm/atomic.h | 142 +++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 arch/csky/include/asm/atomic.h diff --git a/arch/csky/include/asm/atomic.h b/arch/csky/include/asm/atomic.h new file mode 100644 index 000000000000..56c9dc8e91b3 --- /dev/null +++ b/arch/csky/include/asm/atomic.h @@ -0,0 +1,142 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __ASM_CSKY_ATOMIC_H +#define __ASM_CSKY_ATOMIC_H + +#ifdef CONFIG_SMP +#include + +#include +#include + +#define __atomic_acquire_fence() __bar_brarw() + +#define __atomic_release_fence() __bar_brwaw() + +static __always_inline int arch_atomic_read(const atomic_t *v) +{ + return READ_ONCE(v->counter); +} +static __always_inline void arch_atomic_set(atomic_t *v, int i) +{ + WRITE_ONCE(v->counter, i); +} + +#define ATOMIC_OP(op) \ +static __always_inline \ +void arch_atomic_##op(int i, atomic_t *v) \ +{ \ + unsigned long tmp; \ + __asm__ __volatile__ ( \ + "1: ldex.w %0, (%2) \n" \ + " " #op " %0, %1 \n" \ + " stex.w %0, (%2) \n" \ + " bez %0, 1b \n" \ + : "=&r" (tmp) \ + : "r" (i), "r" (&v->counter) \ + : "memory"); \ +} + +ATOMIC_OP(add) +ATOMIC_OP(sub) +ATOMIC_OP(and) +ATOMIC_OP( or) +ATOMIC_OP(xor) + +#undef ATOMIC_OP + +#define ATOMIC_FETCH_OP(op) \ +static __always_inline \ +int arch_atomic_fetch_##op##_relaxed(int i, atomic_t *v) \ +{ \ + register int ret, tmp; \ + __asm__ __volatile__ ( \ + "1: ldex.w %0, (%3) \n" \ + " mov %1, %0 \n" \ + " " #op " %0, %2 \n" \ + " stex.w %0, (%3) \n" \ + " bez %0, 1b \n" \ + : "=&r" (tmp), "=&r" (ret) \ + : "r" (i), "r"(&v->counter) \ + : "memory"); \ + return ret; \ +} + +#define ATOMIC_OP_RETURN(op, c_op) \ +static __always_inline \ +int arch_atomic_##op##_return_relaxed(int i, atomic_t *v) \ +{ \ + return arch_atomic_fetch_##op##_relaxed(i, v) c_op i; \ +} + +#define ATOMIC_OPS(op, c_op) \ + ATOMIC_FETCH_OP(op) \ + ATOMIC_OP_RETURN(op, c_op) + +ATOMIC_OPS(add, +) +ATOMIC_OPS(sub, -) + +#define arch_atomic_fetch_add_relaxed arch_atomic_fetch_add_relaxed +#define arch_atomic_fetch_sub_relaxed arch_atomic_fetch_sub_relaxed + +#define arch_atomic_add_return_relaxed arch_atomic_add_return_relaxed +#define arch_atomic_sub_return_relaxed arch_atomic_sub_return_relaxed + +#undef ATOMIC_OPS +#undef ATOMIC_OP_RETURN + +#define ATOMIC_OPS(op) \ + ATOMIC_FETCH_OP(op) + +ATOMIC_OPS(and) +ATOMIC_OPS( or) +ATOMIC_OPS(xor) + +#define arch_atomic_fetch_and_relaxed arch_atomic_fetch_and_relaxed +#define arch_atomic_fetch_or_relaxed arch_atomic_fetch_or_relaxed +#define arch_atomic_fetch_xor_relaxed arch_atomic_fetch_xor_relaxed + +#undef ATOMIC_OPS + +#undef ATOMIC_FETCH_OP + +#define ATOMIC_OP() \ +static __always_inline \ +int arch_atomic_xchg_relaxed(atomic_t *v, int n) \ +{ \ + return __xchg_relaxed(n, &(v->counter), 4); \ +} \ +static __always_inline \ +int arch_atomic_cmpxchg_relaxed(atomic_t *v, int o, int n) \ +{ \ + return __cmpxchg_relaxed(&(v->counter), o, n, 4); \ +} \ +static __always_inline \ +int arch_atomic_cmpxchg_acquire(atomic_t *v, int o, int n) \ +{ \ + return __cmpxchg_acquire(&(v->counter), o, n, 4); \ +} \ +static __always_inline \ +int arch_atomic_cmpxchg(atomic_t *v, int o, int n) \ +{ \ + return __cmpxchg(&(v->counter), o, n, 4); \ +} + +#define ATOMIC_OPS() \ + ATOMIC_OP() + +ATOMIC_OPS() + +#define arch_atomic_xchg_relaxed arch_atomic_xchg_relaxed +#define arch_atomic_cmpxchg_relaxed arch_atomic_cmpxchg_relaxed +#define arch_atomic_cmpxchg_acquire arch_atomic_cmpxchg_acquire +#define arch_atomic_cmpxchg arch_atomic_cmpxchg + +#undef ATOMIC_OPS +#undef ATOMIC_OP + +#else +#include +#endif + +#endif /* __ASM_CSKY_ATOMIC_H */ -- 2.25.1