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 A3D31C433F5 for ; Thu, 5 May 2022 03:56:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242377AbiEED7t (ORCPT ); Wed, 4 May 2022 23:59:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242381AbiEED7i (ORCPT ); Wed, 4 May 2022 23:59:38 -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 4EF674A3FD; Wed, 4 May 2022 20:55:54 -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 D18FC6135D; Thu, 5 May 2022 03:55:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10CE0C385AE; Thu, 5 May 2022 03:55:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1651722953; bh=PFNl6xABaY2in+HPLdVvyvlQKRywP5jYrBLTCrJwmLQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EUpRYvGbqagkM91KCHl9lnkgT0M4jydo1Y6ta+GWU2KUqBmrdLFm8jStVLcZIFsed a1RIgXuZWvD+s5Y13WJ0IQrQUKU4fwTb5IpgbM3TMbXKpuM8ipOoLuqko9QFs8Ybrc Qh9TnQk9+vMsNht8F/daDwNtQZ8jDPd5wvWbgzB/EgDJtEvTI8ToXhDjmrVbO3puHO oRiB0XGP9uSm6NMcM6QhpwLZ24EMTJuKrLNUpa2Dn6+UsWJ5mCOxIrHOONSpJEvjTo BW1TM8HoViprvZV+l/ZWMdKFMQZAkBcEnkyYClT4Ku7p8JDwg8V/L3DpN/HVdN4r8c zJwNNZFNa3lxQ== From: guoren@kernel.org To: guoren@kernel.org, arnd@arndb.de, palmer@dabbelt.com, mark.rutland@arm.com, will@kernel.org, peterz@infradead.org, boqun.feng@gmail.com, dlustig@nvidia.com, parri.andrea@gmail.com Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Guo Ren Subject: [PATCH V4 3/5] riscv: atomic: Add custom conditional atomic operation implementation Date: Thu, 5 May 2022 11:55:24 +0800 Message-Id: <20220505035526.2974382-4-guoren@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220505035526.2974382-1-guoren@kernel.org> References: <20220505035526.2974382-1-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 Add conditional atomic operations' custom implementation (similar to dec_if_positive), here is the list: - arch_atomic_inc_unless_negative - arch_atomic_dec_unless_positive - arch_atomic64_inc_unless_negative - arch_atomic64_dec_unless_positive Signed-off-by: Guo Ren Signed-off-by: Guo Ren Cc: Palmer Dabbelt Cc: Mark Rutland Cc: Andrea Parri Cc: Dan Lustig --- arch/riscv/include/asm/atomic.h | 82 +++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) diff --git a/arch/riscv/include/asm/atomic.h b/arch/riscv/include/asm/atomic.h index f3c6a6eac02a..0dfe9d857a76 100644 --- a/arch/riscv/include/asm/atomic.h +++ b/arch/riscv/include/asm/atomic.h @@ -310,6 +310,46 @@ ATOMIC_OPS() #undef ATOMIC_OPS #undef ATOMIC_OP +static __always_inline bool arch_atomic_inc_unless_negative(atomic_t *v) +{ + int prev, rc; + + __asm__ __volatile__ ( + "0: lr.w %[p], %[c]\n" + " bltz %[p], 1f\n" + " addi %[rc], %[p], 1\n" + " sc.w.rl %[rc], %[rc], %[c]\n" + " bnez %[rc], 0b\n" + " fence rw, rw\n" + "1:\n" + : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) + : + : "memory"); + return !(prev < 0); +} + +#define arch_atomic_inc_unless_negative arch_atomic_inc_unless_negative + +static __always_inline bool arch_atomic_dec_unless_positive(atomic_t *v) +{ + int prev, rc; + + __asm__ __volatile__ ( + "0: lr.w %[p], %[c]\n" + " bgtz %[p], 1f\n" + " addi %[rc], %[p], -1\n" + " sc.w.rl %[rc], %[rc], %[c]\n" + " bnez %[rc], 0b\n" + " fence rw, rw\n" + "1:\n" + : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) + : + : "memory"); + return !(prev > 0); +} + +#define arch_atomic_dec_unless_positive arch_atomic_dec_unless_positive + static __always_inline int arch_atomic_dec_if_positive(atomic_t *v) { int prev, rc; @@ -331,6 +371,48 @@ static __always_inline int arch_atomic_dec_if_positive(atomic_t *v) #define arch_atomic_dec_if_positive arch_atomic_dec_if_positive #ifndef CONFIG_GENERIC_ATOMIC64 +static __always_inline bool arch_atomic64_inc_unless_negative(atomic64_t *v) +{ + s64 prev; + long rc; + + __asm__ __volatile__ ( + "0: lr.d %[p], %[c]\n" + " bltz %[p], 1f\n" + " addi %[rc], %[p], 1\n" + " sc.d.rl %[rc], %[rc], %[c]\n" + " bnez %[rc], 0b\n" + " fence rw, rw\n" + "1:\n" + : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) + : + : "memory"); + return !(prev < 0); +} + +#define arch_atomic64_inc_unless_negative arch_atomic64_inc_unless_negative + +static __always_inline bool arch_atomic64_dec_unless_positive(atomic64_t *v) +{ + s64 prev; + long rc; + + __asm__ __volatile__ ( + "0: lr.d %[p], %[c]\n" + " bgtz %[p], 1f\n" + " addi %[rc], %[p], -1\n" + " sc.d.rl %[rc], %[rc], %[c]\n" + " bnez %[rc], 0b\n" + " fence rw, rw\n" + "1:\n" + : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) + : + : "memory"); + return !(prev > 0); +} + +#define arch_atomic64_dec_unless_positive arch_atomic64_dec_unless_positive + static __always_inline s64 arch_atomic64_dec_if_positive(atomic64_t *v) { s64 prev; -- 2.25.1