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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0E91BC982C9 for ; Wed, 16 Sep 2026 20:04:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=WC8/pTcNazr1K9NDcSgjZkrCAtMPpi9EWs/x4RXqbf8=; b=gfUDW14B3SuTGJ 0IXLFcXoW+2MMypwIXr4ygHDd5oyretHn9vK1oGtWRN/odOAcimYTTtLEXChZQUiZzpz2knkQUHqf 2D7tcnNqAF1GzX3DFGsY/zb3RzXdTP6sZc595dHrwZVhwqLWZAdS8G6q49I7dFegG7uc0xH5ov+NW GwwfgVZjMD105rgZshnS+Qhv65fNoXckV5oh2DEKjPXim5l6vGUHxmOOu1peuHY44jcd6V0y46BCc dlrtyeJemk0PXpM4tRN+6Lm5gUedbd2geI7S4ra9S4dHZurWton4G/3kNyvaDJKaG4l153EJ9p0Xi jrsUriDSgvujkmNvHU3A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6vs3-0000000A4Jp-2NAD; Wed, 16 Sep 2026 20:04:43 +0000 Received: from mail.mainlining.org ([5.75.144.95]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6vs2-0000000A4JX-0xvr for linux-snps-arc@lists.infradead.org; Wed, 16 Sep 2026 20:04:43 +0000 DKIM-Signature: v=1; a=rsa-sha256; s=202507r; d=mainlining.org; c=relaxed/relaxed; h=Message-ID:Date:Subject:To:From; t=1789588935; bh=1OXxOnbJI64tKjJBlcCcfNg /vmHmtRmMcXj4ssSqyI8=; b=dHD1HWO+3ETnfnxub467tSSinQ6AbN2y51X23r7Bht5gWglVMM Nlok2iptk4U04M82fZ8leUzk+ihL0NaLL0vHYPP724yQVZpGa0nhB+gU/iFlpfsKkxixDusu7lr jNrcKoYFAtqETzQbBh+8faNx0fAIDAJzXgmjmFL/7O9pwJcm2qkOczsS+Y1C2rAGPhsY749WDAS 7QD6arsF02kSpsoXWAicZSTfVh/szo1ff2QIaozy+ivpS0WkK+HyoA64/bjnUA+WbHr4pf5zlmV ZEWf44Kg6LsJGRcm1aQhpiX9vRdMJUTsYyIhtKwB1iy5zZnB74NPLci+wPUR09zctmA==; DKIM-Signature: v=1; a=ed25519-sha256; s=202507e; d=mainlining.org; c=relaxed/relaxed; h=Message-ID:Date:Subject:To:From; t=1789588935; bh=1OXxOnbJI64tKjJBlcCcfNg /vmHmtRmMcXj4ssSqyI8=; b=uI3PUxmRuoMkYc14i+UHDku63fW62n8nkas/svUZhCU0d/DWk0 TsjJew1QWX6XuXf9vkWZTCLMrkejqMK85fDg==; From: Bradley Morgan To: Andrew Morton , Vineet Gupta , Guo Ren , Yoshinori Sato , Rich Felker , Chris Zankel , Max Filippov Cc: Arnd Bergmann , "Paul E . McKenney" , David Laight , John Paul Adrian Glaubitz , linux-snps-arc@lists.infradead.org, linux-csky@vger.kernel.org, linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org, Bradley Morgan Subject: [PATCH v2 2/5] ARC: Emulate two-byte cmpxchg Date: Wed, 16 Sep 2026 20:02:12 +0000 Message-ID: <20260916200215.21774-3-brads@mainlining.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260916200215.21774-1-brads@mainlining.org> References: <20260916200215.21774-1-brads@mainlining.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260916_130442_266787_4A6778D4 X-CRM114-Status: UNSURE ( 8.62 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-snps-arc@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux on Synopsys ARC Processors List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+linux-snps-arc=archiver.kernel.org@lists.infradead.org ARC has no two-byte atomic compare and swap, so the __cmpxchg() macro switch lets case 2 fall through to BUILD_BUG() via default. Route case 2 through the new cmpxchg_emu_u16(), which now takes natural u16 arguments, so the (uintptr_t) casts on _o_ and _n_ become (u16) casts. Signed-off-by: Bradley Morgan --- arch/arc/include/asm/cmpxchg.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arc/include/asm/cmpxchg.h b/arch/arc/include/asm/cmpxchg.h index 76f43db0890f..4451c2011ee3 100644 --- a/arch/arc/include/asm/cmpxchg.h +++ b/arch/arc/include/asm/cmpxchg.h @@ -50,6 +50,9 @@ case 1: \ _prev_ = (__typeof__(*(ptr)))cmpxchg_emu_u8((volatile u8 *__force)_p_, (uintptr_t)_o_, (uintptr_t)_n_); \ break; \ + case 2: \ + _prev_ = (__typeof__(*(ptr)))cmpxchg_emu_u16((volatile u16 *__force)_p_, (u16)_o_, (u16)_n_); \ + break; \ case 4: \ _prev_ = __cmpxchg(_p_, _o_, _n_); \ break; \ -- 2.47.3 _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc