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 E7F7DC982C9 for ; Wed, 16 Sep 2026 20:05:00 +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=BiZixNDc+UETlDdVOu8JeyL+ntclSqjfl4yhKNWnO7c=; b=Q9M5wkPCvZvmuu +C0qDa5L0o8vQMshaiSUTafPMDoOoabw9NWO16kLIuw10jB18USMtx3H9kH6vTYBCYGdQUc7j3nS7 EKnD0w0Qi/93VtUKE+AvYvrg+7iyxM4eFIZkCo3zd8D4Rjfc9JQXzW+8FLSnggnXAFTo2gbAbiISO yz0Aqs/Ol+ElqHn5ACX9ipXvcehrNUUVQvD4mTUKj60iCVR64sm3u131eOsOLNcxqAKbPJZrihBsJ y/72weZhC8Oy8mwA0eqyzPmAAW5M7b7PN4F7shGyAwwLCJONmWn0r92mTU+VOPNxJetvS5yzy03j5 BHCvhfU3pvt5S2qnC0tA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6vsK-0000000A4Ld-2fwQ; Wed, 16 Sep 2026 20:05:00 +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 1x6vsI-0000000A4Kt-1mka for linux-snps-arc@lists.infradead.org; Wed, 16 Sep 2026 20:04:59 +0000 DKIM-Signature: v=1; a=rsa-sha256; s=202507r; d=mainlining.org; c=relaxed/relaxed; h=Message-ID:Date:Subject:To:From; t=1789588936; bh=Cmoc+LvxrB8XTyAuxieF0n1 oKRJqDrHiKarYKzS8wOk=; b=QrcW/ZGsGc/8zHko7LRpzYzG2forpReCVNUoEO/bRUiepdOsvJ Vr1/YF1bZ3Bw296iaAHCQclAkdJYIUR6E02L/Nq8tZfvVx22f7rYSWrsMTbLU1cW0SCq8DSeYnN BVg5WtgXATQq/GpIUm611bYcR9qe+DJR5ZKoAs7PnYH1aR23/+8gPaqNZIrUr/UxGocpngHCThG 6HdW+Z51I7gGEhp+ZvlZ1zvFuicUibVeNY7bBLL5ZQc36Yj4a2dB1Cftd463cVKFVEOrAXDUAFN OOPI0h8Jmnqq22PWIuHK9IRam5z0qayaxb78HeVB4twBKIFxpaTu0fnjuLZrjs0ddrw==; DKIM-Signature: v=1; a=ed25519-sha256; s=202507e; d=mainlining.org; c=relaxed/relaxed; h=Message-ID:Date:Subject:To:From; t=1789588936; bh=Cmoc+LvxrB8XTyAuxieF0n1 oKRJqDrHiKarYKzS8wOk=; b=GUPIOwdm1MvUm482CkvGoF26O4/6Ajr0KBRTAKBF4cQt4KT7lo wqg+pzOKceAgkHmRUcBiSMNVP21Ag6YNpZDg==; 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 5/5] xtensa: Emulate two-byte cmpxchg Date: Wed, 16 Sep 2026 20:02:15 +0000 Message-ID: <20260916200215.21774-6-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_130458_609617_7AFCBD5B X-CRM114-Status: UNSURE ( 9.72 ) 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 Xtensa has no two-byte atomic compare and swap, so the __cmpxchg() switch lets case 2 fall through to __cmpxchg_called_with_bad_pointer(), which is declared but never defined, so a two-byte cmpxchg() fails at link time. Route case 2 through the new cmpxchg_emu_u16(), which takes natural u16 arguments, so the unsigned long old and new narrow at the function boundary. Signed-off-by: Bradley Morgan --- arch/xtensa/include/asm/cmpxchg.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h index b6db4838b175..8dea8e357fc0 100644 --- a/arch/xtensa/include/asm/cmpxchg.h +++ b/arch/xtensa/include/asm/cmpxchg.h @@ -76,6 +76,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) { switch (size) { case 1: return cmpxchg_emu_u8(ptr, old, new); + case 2: return cmpxchg_emu_u16(ptr, old, new); case 4: return __cmpxchg_u32(ptr, old, new); default: __cmpxchg_called_with_bad_pointer(); return old; -- 2.47.3 _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc