From patchwork Thu Jun 13 09:43:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 10992511 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 04C1514BB for ; Thu, 13 Jun 2019 15:44:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E662E21EEB for ; Thu, 13 Jun 2019 15:44:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D9B3B26255; Thu, 13 Jun 2019 15:44:57 +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=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5743F22ADC for ; Thu, 13 Jun 2019 15:44:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727232AbfFMPo4 (ORCPT ); Thu, 13 Jun 2019 11:44:56 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:33468 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731813AbfFMJoH (ORCPT ); Thu, 13 Jun 2019 05:44:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=+F36Qtp9KNZlJRbFfbQN1eq8EHq+227/7sfzGGclHLw=; b=VblDbKsZb0RRpnPdAvevOdbtuG 06yzYUmtWkiIPsoP1nmvo3AnrsDTuJovv6fNdum1MQwQKL25pb99SXJvc4gW0o62hlT7lLlTc/WjS K8qZKqiBN5WxofN6jGW7fAo3QUQf+dfuCfyvrfo4N272eB6mZoLfEfgv+BoGYRDNyl7Vb5xEuzWlM N6FMty3/n4xFBrIv2BT8kRH14dLL54XD4q2x0fsA6G1rQEvtBsX62S7CCnV4Mt/JdWcLV2XjWf64q xbmSBMtbYVIv7Cq/AJJH58RKU1ONXDRSyMYUcP30T1sQI1wMywIlngAo880SbnoVdXJORn4vkMSFl G7SCcZbA==; Received: from mpp-cp1-natpool-1-198.ethz.ch ([82.130.71.198] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hbMH5-0001qr-IT; Thu, 13 Jun 2019 09:44:03 +0000 From: Christoph Hellwig To: Dan Williams , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Jason Gunthorpe , Ben Skeggs Cc: linux-mm@kvack.org, nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-nvdimm@lists.01.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 12/22] memremap: provide an optional internal refcount in struct dev_pagemap Date: Thu, 13 Jun 2019 11:43:15 +0200 Message-Id: <20190613094326.24093-13-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190613094326.24093-1-hch@lst.de> References: <20190613094326.24093-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Provide an internal refcounting logic if no ->ref field is provided in the pagemap passed into devm_memremap_pages so that callers don't have to reinvent it poorly. Signed-off-by: Christoph Hellwig --- include/linux/memremap.h | 4 +++ kernel/memremap.c | 60 ++++++++++++++++++++++++++----- tools/testing/nvdimm/test/iomap.c | 9 +++-- 3 files changed, 62 insertions(+), 11 deletions(-) diff --git a/include/linux/memremap.h b/include/linux/memremap.h index 75b80de6394a..b77ed00851ce 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -88,6 +88,8 @@ struct dev_pagemap_ops { * @altmap: pre-allocated/reserved memory for vmemmap allocations * @res: physical address range covered by @ref * @ref: reference count that pins the devm_memremap_pages() mapping + * @internal_ref: internal reference if @ref is not provided by the caller + * @done: completion for @internal_ref * @dev: host device of the mapping for debug * @data: private data pointer for page_free() * @type: memory type: see MEMORY_* in memory_hotplug.h @@ -98,6 +100,8 @@ struct dev_pagemap { bool altmap_valid; struct resource res; struct percpu_ref *ref; + struct percpu_ref internal_ref; + struct completion done; struct device *dev; enum memory_type type; u64 pci_p2pdma_bus_offset; diff --git a/kernel/memremap.c b/kernel/memremap.c index 5c94ad4f5783..edca4389da68 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -83,6 +83,14 @@ static unsigned long pfn_next(unsigned long pfn) #define for_each_device_pfn(pfn, map) \ for (pfn = pfn_first(map); pfn < pfn_end(map); pfn = pfn_next(pfn)) +static void dev_pagemap_kill(struct dev_pagemap *pgmap) +{ + if (pgmap->ops && pgmap->ops->kill) + pgmap->ops->kill(pgmap); + else + percpu_ref_kill(pgmap->ref); +} + static void devm_memremap_pages_release(void *data) { struct dev_pagemap *pgmap = data; @@ -92,7 +100,8 @@ static void devm_memremap_pages_release(void *data) unsigned long pfn; int nid; - pgmap->ops->kill(pgmap); + dev_pagemap_kill(pgmap); + for_each_device_pfn(pfn, pgmap) put_page(pfn_to_page(pfn)); @@ -121,20 +130,37 @@ static void devm_memremap_pages_release(void *data) "%s: failed to free all reserved pages\n", __func__); } +static void dev_pagemap_percpu_release(struct percpu_ref *ref) +{ + struct dev_pagemap *pgmap = + container_of(ref, struct dev_pagemap, internal_ref); + + complete(&pgmap->done); +} + +static void dev_pagemap_percpu_exit(void *data) +{ + struct dev_pagemap *pgmap = data; + + wait_for_completion(&pgmap->done); + percpu_ref_exit(pgmap->ref); +} + /** * devm_memremap_pages - remap and provide memmap backing for the given resource * @dev: hosting device for @res * @pgmap: pointer to a struct dev_pagemap * * Notes: - * 1/ At a minimum the res, ref and type and ops members of @pgmap must be - * initialized by the caller before passing it to this function + * 1/ At a minimum the res and type members of @pgmap must be initialized + * by the caller before passing it to this function * * 2/ The altmap field may optionally be initialized, in which case altmap_valid * must be set to true * - * 3/ pgmap->ref must be 'live' on entry and will be killed at - * devm_memremap_pages_release() time, or if this routine fails. + * 3/ The ref field may optionally be provided, in which pgmap->ref must be + * 'live' on entry and will be killed at devm_memremap_pages_release() time, + * or if this routine fails. * * 4/ res is expected to be a host memory range that could feasibly be * treated as a "System RAM" range, i.e. not a device mmio range, but @@ -156,10 +182,26 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) pgprot_t pgprot = PAGE_KERNEL; int error, nid, is_ram; - if (!pgmap->ref || !pgmap->ops || !pgmap->ops->kill) - return ERR_PTR(-EINVAL); + if (!pgmap->ref) { + if (pgmap->ops && pgmap->ops->kill) + return ERR_PTR(-EINVAL); + + init_completion(&pgmap->done); + error = percpu_ref_init(&pgmap->internal_ref, + dev_pagemap_percpu_release, 0, GFP_KERNEL); + if (error) + return ERR_PTR(error); + pgmap->ref = &pgmap->internal_ref; + error = devm_add_action_or_reset(dev, dev_pagemap_percpu_exit, + pgmap); + if (error) + return ERR_PTR(error); + } else { + if (!pgmap->ops || !pgmap->ops->kill) + return ERR_PTR(-EINVAL); + } - if (pgmap->ops->page_free) { + if (pgmap->ops && pgmap->ops->page_free) { error = dev_pagemap_enable(dev); if (error) return ERR_PTR(error); @@ -272,7 +314,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) err_pfn_remap: pgmap_array_delete(res); err_array: - pgmap->ops->kill(pgmap); + dev_pagemap_kill(pgmap); return ERR_PTR(error); } EXPORT_SYMBOL_GPL(devm_memremap_pages); diff --git a/tools/testing/nvdimm/test/iomap.c b/tools/testing/nvdimm/test/iomap.c index ee07c4de2b35..3d0e916f9fff 100644 --- a/tools/testing/nvdimm/test/iomap.c +++ b/tools/testing/nvdimm/test/iomap.c @@ -104,9 +104,14 @@ void *__wrap_devm_memremap(struct device *dev, resource_size_t offset, } EXPORT_SYMBOL(__wrap_devm_memremap); -static void nfit_test_kill(void *pgmap) +static void nfit_test_kill(void *data) { - pgmap->ops->kill(pgmap); + struct dev_pagemap *pgmap = data; + + if (pgmap->ops && pgmap->ops->kill) + pgmap->ops->kill(pgmap); + else + percpu_ref_kill(pgmap->ref); } void *__wrap_devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)