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 11CC3C43219 for ; Thu, 24 Nov 2022 09:59:39 +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:In-Reply-To:MIME-Version:References: Message-ID:Subject:CC:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=VfGX5TrBx4MVsl4TmEzmLImt46RSGAIO5L1lGB+eU/U=; b=irK7jzzECTgc/Q RZMCdT2/hL7qUuDUCIW6mXLue++HUl+QFtsCR0bMZAbGDPDO/94jTQ6/cSoewWHIwRfR3iL0goNI/ 5oR7HbyUgaDWwolLRRe76+dyiiGpi/95qI77ZnqH3+6UbVjlEll8fG/1LvKxWyr/FXCMsts00Hi7A yuKfF2YmoQG11dopcyxdvrp7hFO7xLswgssyIIdUeisSFMVXvljNrr0EYJ4YbRwzuKQvSuwcfi/4l iyww/AY+do5CDXU2Q0h+dpDFHHlZgJX7VKxTOo8sR/25POnwij1LrdbcBcJ9U9JixuUCfiiycPxLj bbuYn0LlIiIYi4rgTZsQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oy911-007ORP-Hi; Thu, 24 Nov 2022 09:59:31 +0000 Received: from esa.microchip.iphmx.com ([68.232.154.123]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oy90u-007ONC-Vl for linux-riscv@lists.infradead.org; Thu, 24 Nov 2022 09:59:29 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1669283964; x=1700819964; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=Vwfci9L8RiCJZJk4q1ZcbZBshRi/h91hw6qStmAse7s=; b=ZJ71JOJLZn0u0OoCS2RvdVQX9zsfAyzv/rjO1b13egKJQ+vUz9aWEYls qyOIHZiGOk/HiUWNR63IundZ/2VvKatzH8tLBYLESYuq/tDjNdn+a//g4 pyxRmM1OgtxdELG++W5AlS+kc4O9WQMnT5j4pIPMNFajHosGLSbBXwssA /dlrVqhbfO+AcFlxfkTAr14ZvbGLz48BO03dkAJ8FzOEY5iUBwBY/mApV A56UpT9QuhK1FElHS8tHalWLv/Uci8WXeJTEvQDnlR7QCHdSovG2AOTJ/ sspFctzMRm8JBOoB1HPn6ZDU/F1Hd0aeoK4Q1Vi5/ujaDVg3EeC9bb2WQ A==; X-IronPort-AV: E=Sophos;i="5.96,190,1665471600"; d="scan'208";a="188489524" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa2.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 24 Nov 2022 02:59:18 -0700 Received: from chn-vm-ex02.mchp-main.com (10.10.85.144) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.12; Thu, 24 Nov 2022 02:59:14 -0700 Received: from wendy (10.10.115.15) by chn-vm-ex02.mchp-main.com (10.10.85.144) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.12 via Frontend Transport; Thu, 24 Nov 2022 02:59:11 -0700 Date: Thu, 24 Nov 2022 09:58:53 +0000 From: Conor Dooley To: Samuel Ortiz CC: "Hongren (Zenithal) Zheng" , Palmer Dabbelt , Paul Walmsley , Albert Ou , Atish Patra , Anup Patel , Eric Biederman , Kees Cook , , , , , Michael Kerrisk , , Jiatai He , Heiko Stuebner Subject: Re: [PATCH v3 2/3] RISC-V: uapi: add HWCAP for Bitmanip/Scalar Crypto Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221124_015925_096780_CA056280 X-CRM114-Status: GOOD ( 18.00 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Thu, Nov 24, 2022 at 10:30:21AM +0100, Samuel Ortiz wrote: > On Mon, Jun 13, 2022 at 02:46:35AM +0800, Hongren (Zenithal) Zheng wrote: > > diff --git a/arch/riscv/include/uapi/asm/hwcap.h b/arch/riscv/include/uapi/asm/hwcap.h > > index 46dc3f5ee99f..bfed3e5c338c 100644 > > --- a/arch/riscv/include/uapi/asm/hwcap.h > > +++ b/arch/riscv/include/uapi/asm/hwcap.h > > @@ -22,4 +22,26 @@ > > #define COMPAT_HWCAP_ISA_D (1 << ('D' - 'A')) > > #define COMPAT_HWCAP_ISA_C (1 << ('C' - 'A')) > > > > +/* > > + * HWCAP2 flags - for elf_hwcap2 (in kernel) and AT_HWCAP2 > > + * > > + * As only 32 bits of elf_hwcap (in kernel) could be used > > + * and RISC-V has reserved 26 bits of it, other caps like > > + * bitmanip and crypto can not be placed in AT_HWCAP > > + */ > > Have we agreed that multi-letter ISA extensions would use hwcap to be > exposed to userspace? With so many potential extensions, we could > quickly run out of space on AT_HWCAP2 as well. Palmer whipped up a PoC hwprobe interface (during Plumbers I think) that Heiko is currently looking into - I think his motivation is misaligned access performance. There's a branch but I have no idea if it even compiles... I'm mostly waiting for whatever Heiko comes up with ;) https://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git/log/?h=riscv-hwprobe-v1 This patchset seems to need a rebase anyway per your other reply, but I guess that the new proposed interface would be preferable? Thanks, Conor. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv