From patchwork Tue Apr 2 20:41:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Jordan X-Patchwork-Id: 10882447 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 5E38413B5 for ; Tue, 2 Apr 2019 23:16:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4D66828986 for ; Tue, 2 Apr 2019 23:16:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 40B1F28989; Tue, 2 Apr 2019 23:16:16 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY 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 B95F528986 for ; Tue, 2 Apr 2019 23:16:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726071AbfDBXQP (ORCPT ); Tue, 2 Apr 2019 19:16:15 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:58158 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725912AbfDBXQP (ORCPT ); Tue, 2 Apr 2019 19:16:15 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x32Kd3oq163977; Tue, 2 Apr 2019 20:44:23 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=corp-2018-07-02; bh=SWwbtSuBuVRAsBvShPwVRYWt3xedhjkFQ6ROdmYUzro=; b=ZHUgm2MuOOV0krty4T7QXlZIWISL8Smr5VxapxX5M+iGYwDtJrdgceBsKxYJad72jdFs WS6PXNlId7SQt1sMM422gZWgqsqdoOXN4TuZV9XoD+5A4MgP2ZHg4kYngmD/wvkJ+Xgj OcxQ0Ed7eusFEwspi+mZ4o+M15eUeGihEv2NnqjMkMR9M/SgYecFbMS2YxvOnsYMm27K DbDjihLSkP5+pHWFMCMIJK0R0jhEKczACn8l1Bgh/JSxMplw+viZEOvNtNzKtkwi8JNd G8lMfgtiWXb7/DUUffMG3VNE5jGReclP09wmyGjuhYIpBk/SM3T6LIXX7CzgD5iDuFEY xw== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by aserp2120.oracle.com with ESMTP id 2rj0dnm0bs-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 02 Apr 2019 20:44:23 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x32KfJxi065003; Tue, 2 Apr 2019 20:42:23 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3030.oracle.com with ESMTP id 2rm8f4yk08-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 02 Apr 2019 20:42:22 +0000 Received: from abhmp0009.oracle.com (abhmp0009.oracle.com [141.146.116.15]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x32KgLio031444; Tue, 2 Apr 2019 20:42:21 GMT Received: from localhost.localdomain (/73.60.114.248) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 02 Apr 2019 13:42:21 -0700 From: Daniel Jordan To: akpm@linux-foundation.org Cc: daniel.m.jordan@oracle.com, Alan Tull , Christoph Lameter , Davidlohr Bueso , Moritz Fischer , Wu Hao , linux-mm@kvack.org, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 4/6] fpga/dlf/afu: drop mmap_sem now that locked_vm is atomic Date: Tue, 2 Apr 2019 16:41:56 -0400 Message-Id: <20190402204158.27582-5-daniel.m.jordan@oracle.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190402204158.27582-1-daniel.m.jordan@oracle.com> References: <20190402204158.27582-1-daniel.m.jordan@oracle.com> MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9215 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=3 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904020138 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9215 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=3 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 lowpriorityscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904020138 Sender: linux-fpga-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP With locked_vm now an atomic, there is no need to take mmap_sem as writer. Delete and refactor accordingly. Signed-off-by: Daniel Jordan Cc: Alan Tull Cc: Andrew Morton Cc: Christoph Lameter Cc: Davidlohr Bueso Cc: Moritz Fischer Cc: Wu Hao Cc: Cc: Cc: --- drivers/fpga/dfl-afu-dma-region.c | 40 ++++++++++++------------------- 1 file changed, 15 insertions(+), 25 deletions(-) diff --git a/drivers/fpga/dfl-afu-dma-region.c b/drivers/fpga/dfl-afu-dma-region.c index 08132fd9b6b7..81e3e3a71758 100644 --- a/drivers/fpga/dfl-afu-dma-region.c +++ b/drivers/fpga/dfl-afu-dma-region.c @@ -35,46 +35,36 @@ void afu_dma_region_init(struct dfl_feature_platform_data *pdata) * afu_dma_adjust_locked_vm - adjust locked memory * @dev: port device * @npages: number of pages - * @incr: increase or decrease locked memory * * Increase or decrease the locked memory size with npages input. * * Return 0 on success. * Return -ENOMEM if locked memory size is over the limit and no CAP_IPC_LOCK. */ -static int afu_dma_adjust_locked_vm(struct device *dev, long npages, bool incr) +static int afu_dma_adjust_locked_vm(struct device *dev, long pages) { - unsigned long locked, lock_limit; + unsigned long lock_limit; s64 locked_vm; int ret = 0; /* the task is exiting. */ - if (!current->mm) + if (!current->mm || !pages) return 0; - down_write(¤t->mm->mmap_sem); - - locked_vm = atomic64_read(¤t->mm->locked_vm); - if (incr) { - locked = locked_vm + npages; + locked_vm = atomic64_add_return(pages, ¤t->mm->locked_vm); + WARN_ON_ONCE(locked_vm < 0); + if (pages > 0 && !capable(CAP_IPC_LOCK)) { lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - - if (locked > lock_limit && !capable(CAP_IPC_LOCK)) + if (locked_vm > lock_limit) { ret = -ENOMEM; - else - atomic64_add(npages, ¤t->mm->locked_vm); - } else { - if (WARN_ON_ONCE(npages > locked_vm)) - npages = locked_vm; - atomic64_sub(npages, ¤t->mm->locked_vm); + atomic64_sub(pages, ¤t->mm->locked_vm); + } } dev_dbg(dev, "[%d] RLIMIT_MEMLOCK %c%ld %lld/%lu%s\n", current->pid, - incr ? '+' : '-', npages << PAGE_SHIFT, - (s64)atomic64_read(¤t->mm->locked_vm) << PAGE_SHIFT, - rlimit(RLIMIT_MEMLOCK), ret ? "- exceeded" : ""); - - up_write(¤t->mm->mmap_sem); + (pages > 0) ? '+' : '-', pages << PAGE_SHIFT, + locked_vm << PAGE_SHIFT, rlimit(RLIMIT_MEMLOCK), + ret ? "- exceeded" : ""); return ret; } @@ -94,7 +84,7 @@ static int afu_dma_pin_pages(struct dfl_feature_platform_data *pdata, struct device *dev = &pdata->dev->dev; int ret, pinned; - ret = afu_dma_adjust_locked_vm(dev, npages, true); + ret = afu_dma_adjust_locked_vm(dev, npages); if (ret) return ret; @@ -123,7 +113,7 @@ static int afu_dma_pin_pages(struct dfl_feature_platform_data *pdata, free_pages: kfree(region->pages); unlock_vm: - afu_dma_adjust_locked_vm(dev, npages, false); + afu_dma_adjust_locked_vm(dev, -npages); return ret; } @@ -143,7 +133,7 @@ static void afu_dma_unpin_pages(struct dfl_feature_platform_data *pdata, put_all_pages(region->pages, npages); kfree(region->pages); - afu_dma_adjust_locked_vm(dev, npages, false); + afu_dma_adjust_locked_vm(dev, -npages); dev_dbg(dev, "%ld pages unpinned\n", npages); }