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 X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55093C43381 for ; Thu, 14 Feb 2019 10:15:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10F64222A1 for ; Thu, 14 Feb 2019 10:15:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="aMWKkEGb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438246AbfBNKPs (ORCPT ); Thu, 14 Feb 2019 05:15:48 -0500 Received: from mail-vk1-f194.google.com ([209.85.221.194]:34004 "EHLO mail-vk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727061AbfBNKPr (ORCPT ); Thu, 14 Feb 2019 05:15:47 -0500 Received: by mail-vk1-f194.google.com with SMTP id y14so1267383vkd.1 for ; Thu, 14 Feb 2019 02:15:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=vNcSyhDa48b59JPN1VQvijxe+4UIRP5B7UqXxeP2Yys=; b=aMWKkEGbNu5tb31bxN6FHciu9DP1xk8xnEW01DfnWGN1w2dLske61OkqNFx9CP51A5 81KYqvQ8zgQlicML93pua4TtQP4L253t06QoseEWqfcdZnsKA/8en4iIBGVMLCjQ2Cyv qi5A4QJrTJWJowXI9U09dzflsVVC4Av9ihNtw9pBB59JCiBCh5WOAv7PjzRUFhUtdhaO DCCDowiWR53a0Pq8solR+sJlNKjmHWsnObgRujNzEef2XqOsEcyKmJyNciwejAHg0eCi pIVldd6HyhBv5ffIdP80urCjNtNf5jjLcb9yOy72j36+CTmsxmycmL0Xhi9Lq6r1mcf9 85ZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=vNcSyhDa48b59JPN1VQvijxe+4UIRP5B7UqXxeP2Yys=; b=ah5ElEuMOzvz3l0xdRETMI5wlaIHsbjrC7HeuLix1Y3IbotsZObPAROIwvUdNChC3q 7Uk9GIyG1JpTvPPe4ssgRRWT2iOfp76ORYTFuUXtQaBm5xBSqM6QpbKHOP/WJGoaH+a0 1fNtpwxVN6ndXTPKv+D5YfkLpevnZH2q+9qnKsVeeziSBSUmRKFFBeLQ3HwDhuOsu758 1xkGLCLdeV6wOhBIv2X/nHLZ+0ObQeTdkMjktqYPN2eX2FpJMI6PeQN3K21DMZ/pn8fR 6KH0/cpeLvQdRO+djycDHFsMVajZcqwxnM1E0vSWMfFZ/B/xhvUIH5E/Ct75GxoTIiF+ CIZw== X-Gm-Message-State: AHQUAuaSXz4SxpU1xo7KXA01FnjshlXfWQcCzb567vWaHUz9lIyfOgO9 +vyk923qc259VGAiLi7qC8VUE6bgpa5L9xXbvXvH+fIB X-Google-Smtp-Source: AHgI3IaIF+idRD+3JXKRg5raSyJRkkznFacUMrhp6oSWF6HHWAvZt9xeyj0gIfh4XF8QhS/F71LtLoWtTsKqMaV+9tY= X-Received: by 2002:a1f:9042:: with SMTP id s63mr1462479vkd.17.1550139346077; Thu, 14 Feb 2019 02:15:46 -0800 (PST) MIME-Version: 1.0 References: <20190211151751.12336-1-oded.gabbay@gmail.com> <20190214071114.GA21381@kroah.com> <20190214100727.GA10405@kroah.com> In-Reply-To: <20190214100727.GA10405@kroah.com> From: Oded Gabbay Date: Thu, 14 Feb 2019 12:15:19 +0200 Message-ID: Subject: Re: [PATCH v4 00/15] Habana Labs kernel driver To: Greg KH Cc: "Linux-Kernel@Vger. Kernel. Org" , Mike Rapoport , Olof Johansson , ogabbay@habana.ai, Arnd Bergmann , Joe Perches Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 14, 2019 at 12:07 PM Greg KH wrote: > > On Thu, Feb 14, 2019 at 11:58:41AM +0200, Oded Gabbay wrote: > > On Thu, Feb 14, 2019 at 9:13 AM Oded Gabbay wrote: > > > > > > On Thu, Feb 14, 2019 at 9:11 AM Greg KH wrote: > > > > > > > > On Mon, Feb 11, 2019 at 05:17:36PM +0200, Oded Gabbay wrote: > > > > > Hello, > > > > > This is v4 of the Habana Labs kernel driver patch-set. It contains fixes > > > > > according to reviews done on v3, mainly for the command buffer, sysfs and MMU > > > > > patches. In addition, patch 2/15 was reduced in size from 4.3MB to 1.4MB. > > > > > > > > > > The patch-set is rebased on v5.0-rc6. > > > > > > > > > > Link to v3 cover letter: https://lkml.org/lkml/2019/2/4/1033 > > > > > > > > > > Link to v2 cover letter: https://lkml.org/lkml/2019/1/30/1003 > > > > > > > > > > Link to v1 cover letter: https://lwn.net/Articles/777342/ > > > > > > > > > > I would appricate any feedback, question and/or review. > > > > > > > > There's been some 0-day bot feedback on some of these patches now that I > > > > put them in my -testing branch. So I'm going to drop the patch series > > > > from there now and wait for a v5 of the series that hopefully will have > > > > those issues fixed :) > > > > > > Hi Greg, > > I looked at the 4 warnings I received from your emails, and they all > > appear in i386 architecture. > > I don't want to support 32-bit kernel and I don't intend to support it. > > Can we just specify in kconfig that we don't support it, and then you > > won't get these warnings ? > > No, if you use the correct kernel types and castings, you should be > fine. > > > I initially set in kconfig to support only x86_64, and you told me > > (and you were right) not to limit to that. But I do think I would like > > to disable the driver on i386. > > You might want to not support it on 32bit kernels, but even then, I > think all you need to do here is use the proper kernel types and you > will be ok. > > As an example: > drivers/misc/habanalabs/goya/goya.c: In function 'goya_early_init': > drivers/misc/habanalabs/goya/goya.c:404:4: warning: format '%llu' expects argument of type 'long long unsigned int', but argument 4 has type 'resource_size_t' {aka 'unsigned int'} [-Wformat=] > "Not " HL_NAME "? BAR %d size %llu, expecting %llu\n", > ^~~~~~ > > Use the correct printk type for a resource_size_t. > > You got that warning twice. > > Another one is: > >> drivers/misc/habanalabs/device.c:283:24: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] > volatile u32 *paddr = (volatile u32 *) addr; > > Now using a volatile makes me want to say "you are doing it wrong!", as > yes, you shouldn't be reading directly from a memory pointer, you need > to use the correct iomem accessors, right? > > So I think just fixing this stuff up should be simple, the > resource_size_t fix is needed no matter what size kernel you run on. > > thanks, > > greg k-h ok, got it, will be fixed. Regarding the volatile, this is not an I/O memory. This is host memory that is changed by the device. That's why I wrote in the comment there: /* * paddr is defined as volatile because it points to HOST memory, * which is being written to by the device. Therefore, we can't use * locks to synchronize it and it is not a memory-mapped register space */ Am I missing something here ? I don't think I should use the iomem accessors on host memory, right ? Assuming I'm right, is there another way to ensure the compiler won't optimize this without using the volatile keyword ? Thanks, Oded