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 D4AA6C55174 for ; Wed, 5 Aug 2026 03:53:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version: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:In-Reply-To:References:List-Owner; bh=NTcBSlM5LuKCDc9Ov6EpGoH7qPKq43ytKlh8zg6LOU8=; b=XX7j6tP8udBy7og5YUtdLMLhz8 iV7ZSI79KbgcFxQOUlGHVyXQ44y7u3g324Ug+h+CadzS8c7NHQA53t295WdcZjThkmFzdXcdlPCv4 27WrJVvppkJn+5gMGIoMss1/3PYNqWRsMlss9mBCDI05EV20b/D9gvCKWK4/fK7r0vYMbnwr9n8hR /4CMIt5K76n8onbeMzisv2lflmVgWXJOwgNIT3l+PP941/Mck5kGIzxfrEyZkCWNW+xJ4sO6fk5L8 PMMHJDlxSIYRG5+uovNAG/ykVKx6YvwVPIj/v0eSuckyIpguW4G1beOZJXn9ICF+Yf3Ysp18HJmdL SOWpOLsg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wrSgs-00000003CCS-3hFP; Wed, 05 Aug 2026 03:53:14 +0000 Received: from canpmsgout03.his.huawei.com ([113.46.200.218]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wrSgp-00000003CBh-0vfL for linux-arm-kernel@lists.infradead.org; Wed, 05 Aug 2026 03:53:13 +0000 dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=NTcBSlM5LuKCDc9Ov6EpGoH7qPKq43ytKlh8zg6LOU8=; b=ciB7JbH2jOtlsV83or6ZbFuGdUOa/oqJ1sMZT2E+QXFaGj3y9aEbYhCLtAe8hVKsZqPI8XLSO 7F/rXN8KdAlKXWGFzaALI38bXSleMd7DLPmVUdg0C45hIcZvDE5s64xPDAiiLCQSqSDF0zZDZbL WU9PmPjrBg6HwB/tgb33hsU= Received: from mail.maildlp.com (unknown [172.19.162.197]) by canpmsgout03.his.huawei.com (SkyGuard) with ESMTPS id 4hFGTl5JYjzpSvB; Wed, 5 Aug 2026 11:43:23 +0800 (CST) Received: from kwepemj200003.china.huawei.com (unknown [7.202.194.15]) by mail.maildlp.com (Postfix) with ESMTPS id 011704057D; Wed, 5 Aug 2026 11:52:53 +0800 (CST) Received: from localhost.huawei.com (10.90.31.46) by kwepemj200003.china.huawei.com (7.202.194.15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 5 Aug 2026 11:52:52 +0800 From: Qinxin Xia To: , , , , , , CC: , , , , , Subject: [PATCH] arm64: uaccess: Optimize copy_to/from_user with LSUI extension Date: Wed, 5 Aug 2026 11:52:51 +0800 Message-ID: <20260805035251.2813306-1-xiaqinxin@huawei.com> X-Mailer: git-send-email 2.33.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.90.31.46] X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To kwepemj200003.china.huawei.com (7.202.194.15) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260804_205311_974357_04E3DE35 X-CRM114-Status: UNSURE ( 7.82 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add support for the ARMv9.6/LSUI (Load/Store Unprivileged Immediate) extension to optimize copy_from_user operations. The implementation uses the alternative mechanism to select between the standard unprivileged load-pair sequence and the new ldtp/sttp instruction at runtime based on hardware capability. Co-developed-by: Qi Xi Signed-off-by: Qi Xi Signed-off-by: Qinxin Xia --- arch/arm64/include/asm/asm-uaccess.h | 6 ++++++ arch/arm64/lib/copy_from_user.S | 11 +++++++++++ arch/arm64/lib/copy_to_user.S | 11 +++++++++++ 3 files changed, 28 insertions(+) diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h index 12aa6a283249..4c1b94b275e9 100644 --- a/arch/arm64/include/asm/asm-uaccess.h +++ b/arch/arm64/include/asm/asm-uaccess.h @@ -94,4 +94,10 @@ alternative_else_nop_endif _asm_extable_uaccess 8888b, \l; .endm + + .macro user_ldst_pair l, inst, reg1, reg2, addr, post_inc +8888: \inst \reg1, \reg2, [\addr], \post_inc; + + _asm_extable_uaccess 8888b, \l; + .endm #endif diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S index 400057d607ec..f561a9c07345 100644 --- a/arch/arm64/lib/copy_from_user.S +++ b/arch/arm64/lib/copy_from_user.S @@ -45,7 +45,18 @@ .endm .macro ldp1 reg1, reg2, ptr, val +#ifdef CONFIG_ARM64_LSUI + alternative_if_not ARM64_HAS_LSUI + user_ldp 9997f, \reg1, \reg2, \ptr, \val + alternative_else + .arch_extension lsui + user_ldst_pair 9997f, ldtp, \reg1, \reg2, \ptr, \val + nop + nop + alternative_endif +#else user_ldp 9997f, \reg1, \reg2, \ptr, \val +#endif .endm .macro stp1 reg1, reg2, ptr, val diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S index 819f2e3fc7a9..a77dd153566f 100644 --- a/arch/arm64/lib/copy_to_user.S +++ b/arch/arm64/lib/copy_to_user.S @@ -48,7 +48,18 @@ .endm .macro stp1 reg1, reg2, ptr, val +#ifdef CONFIG_ARM64_LSUI + alternative_if_not ARM64_HAS_LSUI + user_stp 9997f, \reg1, \reg2, \ptr, \val + alternative_else + .arch_extension lsui + user_ldst_pair 9997f, sttp, \reg1, \reg2, \ptr, \val + nop + nop + alternative_endif +#else user_stp 9997f, \reg1, \reg2, \ptr, \val +#endif .endm .macro cpy1 dst, src, count -- 2.33.0