From patchwork Sun May 31 22:48:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11581013 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 280DF60D for ; Sun, 31 May 2020 22:48:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E8A7F20707 for ; Sun, 31 May 2020 22:48:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="OtxxSXSK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E8A7F20707 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 98C298E0003; 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Sun, 31 May 2020 22:48:29 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Sun, 31 May 2020 22:48:29 +0000 Received: from sandstorm.nvidia.com (Not Verified[10.2.56.10]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Sun, 31 May 2020 15:48:29 -0700 From: John Hubbard To: Andrew Morton CC: Andy Walls , Mauro Carvalho Chehab , Souptick Joarder , , LKML , , John Hubbard Subject: [PATCH v2 1/2] mm/gup: introduce pin_user_pages_unlocked Date: Sun, 31 May 2020 15:48:26 -0700 Message-ID: <20200531224827.769427-2-jhubbard@nvidia.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200531224827.769427-1-jhubbard@nvidia.com> References: <20200531224827.769427-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1590965215; bh=V53v56y9lJXy8Ev50du65kbxD+j1cmQc1YhH71s5Kv8=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=OtxxSXSKgIPisVTVmn6pmBnG+uyjI9ccPbrXFSxcz+rpwSv3CFnLtIdjgxZxSSv2p 5ks5OVP/8liP8Ad+e2VVOvJRaW0ctGiBqlegn/Nddg008DoU0xK+QBtWD6enAeS3iR NLE6UZpUXfQsHUiXRMRiAHKD3jw+v3ltspRBycmnMcq8AT6q22UNcAig/yL8rS5moz EKvyLMII8e0BxV1LIGrZo5ZKcrkq1WsvzWN2KI8AElOamFIxHoCkLForTeMcfZiOha UPiTGflB11+Rttp+fbJrz8IoNvXbsPm5XABDBtkW2ghMU25oxrzsBFHYSLbJ9M4NfS 39k1p7v/16HCQ== X-Rspamd-Queue-Id: 199C26C2C X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 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: Introduce pin_user_pages_unlocked(), which is nearly identical to the get_user_pages_unlocked() that it wraps, except that it sets FOLL_PIN and rejects FOLL_GET. As with other pairs of get_user_pages*() and pin_user_pages() API calls, it's prudent to assert that FOLL_PIN is *not* set in the get_user_pages*() call, so add that as part of this. Cc: Souptick Joarder Signed-off-by: John Hubbard --- include/linux/mm.h | 2 ++ mm/gup.c | 23 +++++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index f3fe7371855c..a84befdb54b2 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1713,6 +1713,8 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, int *locked); long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, struct page **pages, unsigned int gup_flags); +long pin_user_pages_unlocked(unsigned long start, unsigned long nr_pages, + struct page **pages, unsigned int gup_flags); 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 87a6a59fe667..8ae5d09adb6b 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2030,6 +2030,12 @@ long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, */ if (WARN_ON_ONCE(gup_flags & FOLL_LONGTERM)) return -EINVAL; + /* + * FOLL_PIN must only be set internally by the pin_user_pages*() APIs, + * never directly by the caller, so enforce that: + */ + if (WARN_ON_ONCE(gup_flags & FOLL_PIN)) + return -EINVAL; down_read(&mm->mmap_sem); ret = __get_user_pages_locked(current, mm, start, nr_pages, pages, NULL, @@ -2939,3 +2945,20 @@ long pin_user_pages(unsigned long start, unsigned long nr_pages, pages, vmas, gup_flags); } EXPORT_SYMBOL(pin_user_pages); + +/* + * pin_user_pages_unlocked() is the FOLL_PIN variant of + * get_user_pages_unlocked(). Behavior is the same, except that this one sets + * FOLL_PIN and rejects FOLL_GET. + */ +long pin_user_pages_unlocked(unsigned long start, unsigned long nr_pages, + struct page **pages, unsigned int gup_flags) +{ + /* FOLL_GET and FOLL_PIN are mutually exclusive. */ + if (WARN_ON_ONCE(gup_flags & FOLL_GET)) + return -EINVAL; + + gup_flags |= FOLL_PIN; + return get_user_pages_unlocked(start, nr_pages, pages, gup_flags); +} +EXPORT_SYMBOL(pin_user_pages_unlocked); From patchwork Sun May 31 22:48:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11581015 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 50BC4913 for ; Sun, 31 May 2020 22:48:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 10B3D2074A for ; 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Sun, 31 May 2020 15:48:18 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Sun, 31 May 2020 15:48:30 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Sun, 31 May 2020 15:48:30 -0700 Received: from HQMAIL109.nvidia.com (172.20.187.15) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Sun, 31 May 2020 22:48:29 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Sun, 31 May 2020 22:48:29 +0000 Received: from sandstorm.nvidia.com (Not Verified[10.2.56.10]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Sun, 31 May 2020 15:48:29 -0700 From: John Hubbard To: Andrew Morton CC: Andy Walls , Mauro Carvalho Chehab , Souptick Joarder , , LKML , , John Hubbard Subject: [PATCH v2 2/2] ivtv: convert get_user_pages() --> pin_user_pages() Date: Sun, 31 May 2020 15:48:27 -0700 Message-ID: <20200531224827.769427-3-jhubbard@nvidia.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200531224827.769427-1-jhubbard@nvidia.com> References: <20200531224827.769427-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1590965298; bh=xH5C6dG4bePEiW5mi0F4Wccp6bZO0ppe4EGiUHwyKL4=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=EPYECVgKWlvBx7tKYa81xMDO35Ip6n41Q8Q3Db4HXLPfCm3EYZO9rz9Ob/ieJmp6/ 66OnusV+qlnv37ZNAoFdRqkxNjXZFwGwQKABQwbRECaPIjmHCsCX5ojsM3NP5CzFkq lKxje8mwJugXFM1noM0aFme0oWXvHLn0rd5q1sQ8nxAsBive1ELKTDydUYE0QRnEae QrD5CXPO2SYEaISjKo96Ac3D+gpJC0cOweclCpoXKzocWoKFiRWcqn5lz27hh+EAJD wQYUUQSISX3zPOpM3IglFGGImq9pfCTItPHlqlR6gcfviCjfsH+4wLRgVhKjKY3xVx vgw5Jpq02Iazg== X-Rspamd-Queue-Id: 6DDFD180D0180 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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: This code was using get_user_pages*(), in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Signed-off-by: John Hubbard --- drivers/media/pci/ivtv/ivtv-udma.c | 19 ++++++------------- drivers/media/pci/ivtv/ivtv-yuv.c | 17 ++++++----------- drivers/media/pci/ivtv/ivtvfb.c | 4 ++-- 3 files changed, 14 insertions(+), 26 deletions(-) diff --git a/drivers/media/pci/ivtv/ivtv-udma.c b/drivers/media/pci/ivtv/ivtv-udma.c index 5f8883031c9c..0d8372cc364a 100644 --- a/drivers/media/pci/ivtv/ivtv-udma.c +++ b/drivers/media/pci/ivtv/ivtv-udma.c @@ -92,7 +92,7 @@ int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr, { struct ivtv_dma_page_info user_dma; struct ivtv_user_dma *dma = &itv->udma; - int i, err; + int err; IVTV_DEBUG_DMA("ivtv_udma_setup, dst: 0x%08x\n", (unsigned int)ivtv_dest_addr); @@ -111,16 +111,15 @@ int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr, return -EINVAL; } - /* Get user pages for DMA Xfer */ - err = get_user_pages_unlocked(user_dma.uaddr, user_dma.page_count, + /* Pin user pages for DMA Xfer */ + err = pin_user_pages_unlocked(user_dma.uaddr, user_dma.page_count, dma->map, FOLL_FORCE); if (user_dma.page_count != err) { IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n", err, user_dma.page_count); if (err >= 0) { - for (i = 0; i < err; i++) - put_page(dma->map[i]); + unpin_user_pages(dma->map, err); return -EINVAL; } return err; @@ -130,9 +129,7 @@ int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr, /* Fill SG List with new values */ if (ivtv_udma_fill_sg_list(dma, &user_dma, 0) < 0) { - for (i = 0; i < dma->page_count; i++) { - put_page(dma->map[i]); - } + unpin_user_pages(dma->map, dma->page_count); dma->page_count = 0; return -ENOMEM; } @@ -153,7 +150,6 @@ int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr, void ivtv_udma_unmap(struct ivtv *itv) { struct ivtv_user_dma *dma = &itv->udma; - int i; IVTV_DEBUG_INFO("ivtv_unmap_user_dma\n"); @@ -169,10 +165,7 @@ void ivtv_udma_unmap(struct ivtv *itv) /* sync DMA */ ivtv_udma_sync_for_cpu(itv); - /* Release User Pages */ - for (i = 0; i < dma->page_count; i++) { - put_page(dma->map[i]); - } + unpin_user_pages(dma->map, dma->page_count); dma->page_count = 0; } diff --git a/drivers/media/pci/ivtv/ivtv-yuv.c b/drivers/media/pci/ivtv/ivtv-yuv.c index cd2fe2d444c0..5f7dc9771f8d 100644 --- a/drivers/media/pci/ivtv/ivtv-yuv.c +++ b/drivers/media/pci/ivtv/ivtv-yuv.c @@ -30,7 +30,6 @@ static int ivtv_yuv_prep_user_dma(struct ivtv *itv, struct ivtv_user_dma *dma, struct yuv_playback_info *yi = &itv->yuv_info; u8 frame = yi->draw_frame; struct yuv_frame_info *f = &yi->new_frame_info[frame]; - int i; int y_pages, uv_pages; unsigned long y_buffer_offset, uv_buffer_offset; int y_decode_height, uv_decode_height, y_size; @@ -62,12 +61,12 @@ static int ivtv_yuv_prep_user_dma(struct ivtv *itv, struct ivtv_user_dma *dma, ivtv_udma_get_page_info (&y_dma, (unsigned long)args->y_source, 720 * y_decode_height); ivtv_udma_get_page_info (&uv_dma, (unsigned long)args->uv_source, 360 * uv_decode_height); - /* Get user pages for DMA Xfer */ - y_pages = get_user_pages_unlocked(y_dma.uaddr, + /* Pin user pages for DMA Xfer */ + y_pages = pin_user_pages_unlocked(y_dma.uaddr, y_dma.page_count, &dma->map[0], FOLL_FORCE); uv_pages = 0; /* silence gcc. value is set and consumed only if: */ if (y_pages == y_dma.page_count) { - uv_pages = get_user_pages_unlocked(uv_dma.uaddr, + uv_pages = pin_user_pages_unlocked(uv_dma.uaddr, uv_dma.page_count, &dma->map[y_pages], FOLL_FORCE); } @@ -81,8 +80,7 @@ static int ivtv_yuv_prep_user_dma(struct ivtv *itv, struct ivtv_user_dma *dma, uv_pages, uv_dma.page_count); if (uv_pages >= 0) { - for (i = 0; i < uv_pages; i++) - put_page(dma->map[y_pages + i]); + unpin_user_pages(&dma->map[y_pages], uv_pages); rc = -EFAULT; } else { rc = uv_pages; @@ -93,8 +91,7 @@ static int ivtv_yuv_prep_user_dma(struct ivtv *itv, struct ivtv_user_dma *dma, y_pages, y_dma.page_count); } if (y_pages >= 0) { - for (i = 0; i < y_pages; i++) - put_page(dma->map[i]); + unpin_user_pages(dma->map, y_pages); /* * Inherit the -EFAULT from rc's * initialization, but allow it to be @@ -112,9 +109,7 @@ static int ivtv_yuv_prep_user_dma(struct ivtv *itv, struct ivtv_user_dma *dma, /* Fill & map SG List */ if (ivtv_udma_fill_sg_list (dma, &uv_dma, ivtv_udma_fill_sg_list (dma, &y_dma, 0)) < 0) { IVTV_DEBUG_WARN("could not allocate bounce buffers for highmem userspace buffers\n"); - for (i = 0; i < dma->page_count; i++) { - put_page(dma->map[i]); - } + unpin_user_pages(dma->map, dma->page_count); dma->page_count = 0; return -ENOMEM; } diff --git a/drivers/media/pci/ivtv/ivtvfb.c b/drivers/media/pci/ivtv/ivtvfb.c index 0c2859844081..e2d56dca5be4 100644 --- a/drivers/media/pci/ivtv/ivtvfb.c +++ b/drivers/media/pci/ivtv/ivtvfb.c @@ -281,10 +281,10 @@ static int ivtvfb_prep_dec_dma_to_device(struct ivtv *itv, /* Map User DMA */ if (ivtv_udma_setup(itv, ivtv_dest_addr, userbuf, size_in_bytes) <= 0) { mutex_unlock(&itv->udma.lock); - IVTVFB_WARN("ivtvfb_prep_dec_dma_to_device, Error with get_user_pages: %d bytes, %d pages returned\n", + IVTVFB_WARN("ivtvfb_prep_dec_dma_to_device, Error with pin_user_pages: %d bytes, %d pages returned\n", size_in_bytes, itv->udma.page_count); - /* get_user_pages must have failed completely */ + /* pin_user_pages must have failed completely */ return -EIO; }