From patchwork Tue Nov 20 23:12:54 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 10691421 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5CE5816B1 for ; Tue, 20 Nov 2018 23:25:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4A0652AC4E for ; Tue, 20 Nov 2018 23:25:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3DD8C2AC59; Tue, 20 Nov 2018 23:25:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D12812AC4E for ; Tue, 20 Nov 2018 23:25:25 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A516D6E48E; Tue, 20 Nov 2018 23:25:24 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id 90A976E48E for ; Tue, 20 Nov 2018 23:25:22 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Nov 2018 15:25:22 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,258,1539673200"; d="scan'208";a="107958492" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by fmsmga004.fm.intel.com with ESMTP; 20 Nov 2018 15:25:21 -0800 Subject: [PATCH v8 1/7] mm, devm_memremap_pages: Mark devm_memremap_pages() EXPORT_SYMBOL_GPL From: Dan Williams To: akpm@linux-foundation.org Date: Tue, 20 Nov 2018 15:12:54 -0800 Message-ID: <154275557457.76910.16923571232582744134.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <154275556908.76910.8966087090637564219.stgit@dwillia2-desk3.amr.corp.intel.com> References: <154275556908.76910.8966087090637564219.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Michal Hocko , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org, =?utf-8?b?SsOpcsO0bWU=?= Glisse , torvalds@linux-foundation.org, Christoph Hellwig Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP devm_memremap_pages() is a facility that can create struct page entries for any arbitrary range and give drivers the ability to subvert core aspects of page management. Specifically the facility is tightly integrated with the kernel's memory hotplug functionality. It injects an altmap argument deep into the architecture specific vmemmap implementation to allow allocating from specific reserved pages, and it has Linux specific assumptions about page structure reference counting relative to get_user_pages() and get_user_pages_fast(). It was an oversight and a mistake that this was not marked EXPORT_SYMBOL_GPL from the outset. Again, devm_memremap_pagex() exposes and relies upon core kernel internal assumptions and will continue to evolve along with 'struct page', memory hotplug, and support for new memory types / topologies. Only an in-kernel GPL-only driver is expected to keep up with this ongoing evolution. This interface, and functionality derived from this interface, is not suitable for kernel-external drivers. Cc: Michal Hocko Cc: "Jérôme Glisse" Reviewed-by: Christoph Hellwig Signed-off-by: Dan Williams Acked-by: Michal Hocko --- kernel/memremap.c | 2 +- tools/testing/nvdimm/test/iomap.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/memremap.c b/kernel/memremap.c index 9eced2cc9f94..61dbcaa95530 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -233,7 +233,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) err_array: return ERR_PTR(error); } -EXPORT_SYMBOL(devm_memremap_pages); +EXPORT_SYMBOL_GPL(devm_memremap_pages); unsigned long vmem_altmap_offset(struct vmem_altmap *altmap) { diff --git a/tools/testing/nvdimm/test/iomap.c b/tools/testing/nvdimm/test/iomap.c index ff9d3a5825e1..ed18a0cbc0c8 100644 --- a/tools/testing/nvdimm/test/iomap.c +++ b/tools/testing/nvdimm/test/iomap.c @@ -113,7 +113,7 @@ void *__wrap_devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) return nfit_res->buf + offset - nfit_res->res.start; return devm_memremap_pages(dev, pgmap); } -EXPORT_SYMBOL(__wrap_devm_memremap_pages); +EXPORT_SYMBOL_GPL(__wrap_devm_memremap_pages); pfn_t __wrap_phys_to_pfn_t(phys_addr_t addr, unsigned long flags) {