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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 3D9ADC433DF for ; Tue, 13 Oct 2020 23:51:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BC48721D7B for ; Tue, 13 Oct 2020 23:51:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Hpvg8JHO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BC48721D7B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5BB376B00A6; Tue, 13 Oct 2020 19:51:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 56CCD6B00A7; Tue, 13 Oct 2020 19:51:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4A8BE6B00A8; Tue, 13 Oct 2020 19:51:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0208.hostedemail.com [216.40.44.208]) by kanga.kvack.org (Postfix) with ESMTP id 1E9046B00A6 for ; Tue, 13 Oct 2020 19:51:10 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id C8EE1180AD806 for ; Tue, 13 Oct 2020 23:51:09 +0000 (UTC) X-FDA: 77368550658.28.hose68_2d02ece27207 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin28.hostedemail.com (Postfix) with ESMTP id A9DBE6C05 for ; Tue, 13 Oct 2020 23:51:09 +0000 (UTC) X-HE-Tag: hose68_2d02ece27207 X-Filterd-Recvd-Size: 8024 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Tue, 13 Oct 2020 23:51:09 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A86F621D81; Tue, 13 Oct 2020 23:51:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602633068; bh=sokyfmEtwUI9+oH3PBobfQZhK0pyF3bNg5sSRsusGTU=; h=Date:From:To:Subject:In-Reply-To:From; b=Hpvg8JHO2Omls4zu3pFjKN303dM35vk1eDC+jknYwkZVuwNsn0d4jdjgRz9qzMwXP wOrxBfOYBFSrkTD8AaJdYa1vU2Hd1klyD94RhXZYZcN9oeSGtykw8IhthcSpllU7qf VxioBQz9X6sAVMVFd1KEZGpom/IZiKKPHvBizc8A= Date: Tue, 13 Oct 2020 16:51:06 -0700 From: Andrew Morton To: airlied@linux.ie, akpm@linux-foundation.org, ard.biesheuvel@linaro.org, ardb@kernel.org, benh@kernel.crashing.org, bhelgaas@google.com, boris.ostrovsky@oracle.com, bp@alien8.de, Brice.Goglin@inria.fr, bskeggs@redhat.com, catalin.marinas@arm.com, dan.j.williams@intel.com, daniel@ffwll.ch, dave.hansen@linux.intel.com, dave.jiang@intel.com, david@redhat.com, gregkh@linuxfoundation.org, hpa@zytor.com, hulkci@huawei.com, ira.weiny@intel.com, jgg@mellanox.com, jglisse@redhat.com, jgross@suse.com, jmoyer@redhat.com, joao.m.martins@oracle.com, Jonathan.Cameron@huawei.com, justin.he@arm.com, linux-mm@kvack.org, lkp@intel.com, luto@kernel.org, mingo@redhat.com, mm-commits@vger.kernel.org, mpe@ellerman.id.au, pasha.tatashin@soleen.com, paulus@ozlabs.org, peterz@infradead.org, rafael.j.wysocki@intel.com, rdunlap@infradead.org, richard.weiyang@linux.alibaba.com, rppt@linux.ibm.com, sstabellini@kernel.org, tglx@linutronix.de, thomas.lendacky@amd.com, torvalds@linux-foundation.org, vgoyal@redhat.com, vishal.l.verma@intel.com, will@kernel.org, yanaijie@huawei.com Subject: [patch 051/181] device-dax: add a range mapping allocation attribute Message-ID: <20201013235106._mRXUNr8h%akpm@linux-foundation.org> In-Reply-To: <20201013164658.3bfd96cc224d8923e66a9f4e@linux-foundation.org> User-Agent: s-nail v14.8.16 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: =46rom: Joao Martins Subject: device-dax: add a range mapping allocation attribute Add a sysfs attribute which denotes a range from the dax region to be allocated. It's an write only @mapping sysfs attribute in the format of '-' to allocate a range. @start and @end use hexadecimal values and the @pgoff is implicitly ordered wrt to previous writes to @mapping sysfs e.g. a write of a range of length 1G the pgoff is 0..1G(-4K), a second write will use @pgoff for 1G+4K... This range mapping interface is useful for: 1) Application which want to implement its own allocation logic, and thus pick the desired ranges from dax_region. 2) For use cases like VMM fast restart[0] where after kexec we want to the same gpa<->phys mappings (as originally created before kexec). [0] https://static.sched.com/hosted_files/kvmforum2019/66/VMM-fast-restart_= kvmforum2019.pdf Link: https://lkml.kernel.org/r/159643106970.4062302.10402616567780784722.s= tgit@dwillia2-desk3.amr.corp.intel.com Link: https://lore.kernel.org/r/20200716172913.19658-5-joao.m.martins@oracl= e.com Link: https://lkml.kernel.org/r/160106119570.30709.4548889722645210610.stgi= t@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Joao Martins Signed-off-by: Dan Williams Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Ard Biesheuvel Cc: Benjamin Herrenschmidt Cc: Ben Skeggs Cc: Bjorn Helgaas Cc: Borislav Petkov Cc: Boris Ostrovsky Cc: Brice Goglin Cc: Catalin Marinas Cc: Daniel Vetter Cc: Dave Hansen Cc: Dave Jiang Cc: David Airlie Cc: David Hildenbrand Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Hulk Robot Cc: Ingo Molnar Cc: Ira Weiny Cc: Jason Gunthorpe Cc: Jason Yan Cc: Jeff Moyer Cc: "J=C3=A9r=C3=B4me Glisse" Cc: Jia He Cc: Jonathan Cameron Cc: Juergen Gross Cc: kernel test robot Cc: Michael Ellerman Cc: Mike Rapoport Cc: Paul Mackerras Cc: Pavel Tatashin Cc: Peter Zijlstra Cc: "Rafael J. Wysocki" Cc: Randy Dunlap Cc: Stefano Stabellini Cc: Thomas Gleixner Cc: Tom Lendacky Cc: Vishal Verma Cc: Vivek Goyal Cc: Wei Yang Cc: Will Deacon Signed-off-by: Andrew Morton --- drivers/dax/bus.c | 64 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) --- a/drivers/dax/bus.c~device-dax-add-a-range-mapping-allocation-attribute +++ a/drivers/dax/bus.c @@ -1043,6 +1043,67 @@ static ssize_t size_store(struct device } static DEVICE_ATTR_RW(size); =20 +static ssize_t range_parse(const char *opt, size_t len, struct range *rang= e) +{ + unsigned long long addr =3D 0; + char *start, *end, *str; + ssize_t rc =3D EINVAL; + + str =3D kstrdup(opt, GFP_KERNEL); + if (!str) + return rc; + + end =3D str; + start =3D strsep(&end, "-"); + if (!start || !end) + goto err; + + rc =3D kstrtoull(start, 16, &addr); + if (rc) + goto err; + range->start =3D addr; + + rc =3D kstrtoull(end, 16, &addr); + if (rc) + goto err; + range->end =3D addr; + +err: + kfree(str); + return rc; +} + +static ssize_t mapping_store(struct device *dev, struct device_attribute *= attr, + const char *buf, size_t len) +{ + struct dev_dax *dev_dax =3D to_dev_dax(dev); + struct dax_region *dax_region =3D dev_dax->region; + size_t to_alloc; + struct range r; + ssize_t rc; + + rc =3D range_parse(buf, len, &r); + if (rc) + return rc; + + rc =3D -ENXIO; + device_lock(dax_region->dev); + if (!dax_region->dev->driver) { + device_unlock(dax_region->dev); + return rc; + } + device_lock(dev); + + to_alloc =3D range_len(&r); + if (alloc_is_aligned(dev_dax, to_alloc)) + rc =3D alloc_dev_dax_range(dev_dax, r.start, to_alloc); + device_unlock(dev); + device_unlock(dax_region->dev); + + return rc =3D=3D 0 ? len : rc; +} +static DEVICE_ATTR_WO(mapping); + static ssize_t align_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -1175,6 +1236,8 @@ static umode_t dev_dax_visible(struct ko return 0; if (a =3D=3D &dev_attr_numa_node.attr && !IS_ENABLED(CONFIG_NUMA)) return 0; + if (a =3D=3D &dev_attr_mapping.attr && is_static(dax_region)) + return 0; if ((a =3D=3D &dev_attr_align.attr || a =3D=3D &dev_attr_size.attr) && is_static(dax_region)) return 0444; @@ -1184,6 +1247,7 @@ static umode_t dev_dax_visible(struct ko static struct attribute *dev_dax_attributes[] =3D { &dev_attr_modalias.attr, &dev_attr_size.attr, + &dev_attr_mapping.attr, &dev_attr_target_node.attr, &dev_attr_align.attr, &dev_attr_resource.attr, _