From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C66E2153BE4 for ; Tue, 22 Oct 2024 21:00:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.177.32 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729630845; cv=none; b=X1ulNH5ZjdvkT9XmdR7RTTD89mhBxquvaevG2rwFzBEf8zDpYV+PbXOQq//CI3H2jPDya4PyHBMuckwJfVyTgwscRTmzb1ZmVrueYcFXpMHJwb83FM6pVEPJDgknmK/r/Jsuq5GkhGPlERejtuH70E2OI2ffC7dc4ol3xboAs9o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729630845; c=relaxed/simple; bh=975ZlWrtltl9tmjelYdfVdmVkrY/EgswLs1eBXVDGI4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=D1P4f925iUS6SSD+a9eoPnvWumaGaJMd7JnlMCLZ3QR7m74kqJi0D8dD7XqeTwP6vZZL2FVrJ0GV9ssaHGKIxZQpLK4BSxdMtWQV7r08tNIQKlqTygPv8Wt1HL3Dm5iXDyIn3Vop5tWtr3LNrm4ugUwbxHX40CRYYPGrYqr3Vbw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com; spf=pass smtp.mailfrom=oracle.com; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b=RYkTrAIh; arc=none smtp.client-ip=205.220.177.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="RYkTrAIh" Received: from pps.filterd (m0333520.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 49MKqLn5009702; Tue, 22 Oct 2024 21:00:41 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :date:from:in-reply-to:message-id:references:subject:to; s= corp-2023-11-20; bh=LzaKpkZYRJZsQLdeV5e4KMjA+eBDzDZi/X3sdKgMo4c=; b= RYkTrAIhm9ovT8XaW3Mnc8y8NuCh5uHoFdCpjhiNtbwORE8lS3u99w07JRzhWYRZ tLquyIrcG/Wx53DLqHGdDK3qtOiEA6rKZAPfw5ouoTFHYlANiT9BkDHBID2gzZti E08Lvn39XeSdyCPTzLw4zGoxB0q2C8XrTHXprdwxDsgm4xLwcTGO6LciDm+LEShV qBjsJuKfSaiCEFGQj3VJY9WEpHvEyR2Qw5ORgyd9/I7H8RlBcV5O5aSYDcJF9ZZN jDlxRCguUBYOHiFT2xh48kO5nXb0K+Dt3LD+kjT3kR9+5mdpG3TjO9X+WkwrNQIk 7RF88OJDr8Rj7hFxnEWxEQ== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 42c5456s6r-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 22 Oct 2024 21:00:41 +0000 (GMT) Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 49MJpfIF012058; Tue, 22 Oct 2024 21:00:40 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 42c3781aak-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 22 Oct 2024 21:00:40 +0000 Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 49ML0dEc016716; Tue, 22 Oct 2024 21:00:40 GMT Received: from ca-dev63.us.oracle.com (ca-dev63.us.oracle.com [10.211.8.221]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 42c3781a7p-2; Tue, 22 Oct 2024 21:00:40 +0000 From: Steve Sistare To: iommu@lists.linux.dev Cc: Jason Gunthorpe , Kevin Tian , Nicolin Chen , Steve Sistare Subject: [PATCH V5 1/9] mm/gup: folio_add_pins Date: Tue, 22 Oct 2024 14:00:30 -0700 Message-Id: <1729630838-24586-2-git-send-email-steven.sistare@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1729630838-24586-1-git-send-email-steven.sistare@oracle.com> References: <1729630838-24586-1-git-send-email-steven.sistare@oracle.com> X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-22_23,2024-10-22_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 malwarescore=0 suspectscore=0 adultscore=0 mlxscore=0 spamscore=0 mlxlogscore=999 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2409260000 definitions=main-2410220135 X-Proofpoint-ORIG-GUID: OiFEb4A-bpf2lw-smiPmmNM76HGYmffr X-Proofpoint-GUID: OiFEb4A-bpf2lw-smiPmmNM76HGYmffr Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Export a function that adds pins to an already-pinned huge-page folio. This allows any range of small pages within the folio to be unpinned later. For example, pages pinned via memfd_pin_folios and modified by folio_add_pins could be unpinned via unpin_user_page(s). Suggested-by: Jason Gunthorpe Suggested-by: David Hildenbrand Signed-off-by: Steve Sistare Acked-by: David Hildenbrand Reviewed-by: Jason Gunthorpe --- include/linux/mm.h | 1 + mm/gup.c | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index ecf63d2..f9de33a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2524,6 +2524,7 @@ long pin_user_pages_unlocked(unsigned long start, unsigned long nr_pages, long memfd_pin_folios(struct file *memfd, loff_t start, loff_t end, struct folio **folios, unsigned int max_folios, pgoff_t *offset); +int folio_add_pins(struct folio *folio, unsigned int pins); int get_user_pages_fast(unsigned long start, int nr_pages, unsigned int gup_flags, struct page **pages); diff --git a/mm/gup.c b/mm/gup.c index a82890b..4ac3e567 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -3717,3 +3717,27 @@ long memfd_pin_folios(struct file *memfd, loff_t start, loff_t end, return ret; } EXPORT_SYMBOL_GPL(memfd_pin_folios); + +/** + * folio_add_pins() - add pins to an already-pinned folio + * @folio: the folio to add more pins to + * @pins: number of pins to add + * + * Try to add more pins to an already-pinned folio. The semantics + * of the pin (e.g., FOLL_WRITE) follow any existing pin and cannot + * be changed. + * + * This function is helpful when having obtained a pin on a large folio + * using memfd_pin_folios(), but wanting to logically unpin parts + * (e.g., individual pages) of the folio later, for example, using + * unpin_user_page_range_dirty_lock(). + * + * This is not the right interface to initially pin a folio. + */ +int folio_add_pins(struct folio *folio, unsigned int pins) +{ + VM_WARN_ON_ONCE(!folio_maybe_dma_pinned(folio)); + + return try_grab_folio(folio, pins, FOLL_PIN); +} +EXPORT_SYMBOL_GPL(folio_add_pins); -- 1.8.3.1