From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (bilbo.ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3xWQJv4QbGzDqXp for ; Tue, 15 Aug 2017 05:14:23 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [103.22.144.67]) by bilbo.ozlabs.org (Postfix) with ESMTP id 3xWQJt0QwVz8tV0 for ; Tue, 15 Aug 2017 05:14:22 +1000 (AEST) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3xWQJq0Tm4z9t3p for ; Tue, 15 Aug 2017 05:14:18 +1000 (AEST) Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v7EJ9VGg062870 for ; Mon, 14 Aug 2017 15:14:16 -0400 Received: from e14.ny.us.ibm.com (e14.ny.us.ibm.com [129.33.205.204]) by mx0b-001b2d01.pphosted.com with ESMTP id 2cbevh09r1-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 14 Aug 2017 15:14:15 -0400 Received: from localhost by e14.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 14 Aug 2017 15:14:15 -0400 Date: Mon, 14 Aug 2017 12:14:09 -0700 From: Sukadev Bhattiprolu To: Nicholas Piggin Cc: Michael Ellerman , Benjamin Herrenschmidt , mikey@neuling.org, stewart@linux.vnet.ibm.com, apopple@au1.ibm.com, hbabu@us.ibm.com, oohall@gmail.com, linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 01/17] powerpc/vas: Define macros, register fields and structures References: <1502233622-9330-1-git-send-email-sukadev@linux.vnet.ibm.com> <1502233622-9330-2-git-send-email-sukadev@linux.vnet.ibm.com> <877ey6sp03.fsf@concordia.ellerman.id.au> <20170814160522.4f9b517a@roar.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170814160522.4f9b517a@roar.ozlabs.ibm.com> Message-Id: <20170814191409.GA24096@us.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Nicholas Piggin [npiggin@gmail.com] wrote: > On Mon, 14 Aug 2017 15:21:48 +1000 > Michael Ellerman wrote: > > > Sukadev Bhattiprolu writes: > > > > arch/powerpc/include/asm/vas.h | 35 ++++ > > > arch/powerpc/include/uapi/asm/vas.h | 25 +++ > > > > I thought we weren't exposing VAS to userspace yet? > > > > If we are then we need to get things straight WRT copy/paste abort. > > No we should not be. This might be just a leftover hunk that should > be moved to a future series. Yes, I should have posted patches 14..17 separately as an RFC that goes on top of the VAS kernel patches 1..13. > > At the moment (as far as I understand) it should be limited to > preempt-disabled, process context, kernel users which avoids any > concern for switch_to. > In the FTW case, there is no data transfer from user space to the hardware. i.e the copy/paste submit a NULL CRB and hardware will be configured (see ->fifo_disable setting in winctx) to ignore any data they specify in the CRB. Would we be able to allow copy/paste from user space in that case? Sukadev