From patchwork Tue Feb 4 02:56:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sergey Senozhatsky X-Patchwork-Id: 11363923 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 318111395 for ; Tue, 4 Feb 2020 02:56:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0BBE820732 for ; Tue, 4 Feb 2020 02:56:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Em5+Jugv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726984AbgBDC4u (ORCPT ); Mon, 3 Feb 2020 21:56:50 -0500 Received: from mail-pg1-f193.google.com ([209.85.215.193]:45548 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726924AbgBDC4u (ORCPT ); Mon, 3 Feb 2020 21:56:50 -0500 Received: by mail-pg1-f193.google.com with SMTP id b9so8876964pgk.12 for ; Mon, 03 Feb 2020 18:56:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=XCoXerpkibNMJc6Hgw89GNrbvkXQaydO3ktnkMY7ZuE=; b=Em5+Jugv6xehllNNi4uXLdPgJKITfVmMdCMwbomGAaIkpILIy4eYQPGKhp1NtWjVq2 ye3lOS2fg8bMbgh/kA3dW/ky3AU7lYGliacB1ILU4nhkHM7LknL91+8RTQs/a1qXo8tp kDP78o2Z4gdEWplfC18X7pnQJfBZITHEHcoQA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=XCoXerpkibNMJc6Hgw89GNrbvkXQaydO3ktnkMY7ZuE=; b=bjG+Q22kJHM0jwfrj//Ax60pvQRotxq+sI5hFX8rurhg+U3FUEXapZzEpj1yvjFqPC Mw2kJHZWGdxsxfEdj+EuAM25JU9jyXdwgF9YZ0JZ1R/2IEkSXrOm3CozzaHIjHRwiI5G 5HT6bqTZAjMzAX3sD3TUmt5yBdiwPu9oDxYNt+pDimFSwGaSHSk6gFlk+g5QsgGLP6LC UCJ8dsR4Yj6QYzqBjePweOu5WvRHm1rwRH5oNeTs8A20hXcGECRGt6S5qqv8jUlklcH8 NdV1DGNMhid9kgCz0F/7qOHbWpjIgCRqn3J7PGh/XBRGP1/kgaRrk5je2rrQoaNZWr/a ZOgQ== X-Gm-Message-State: APjAAAXrSFKE0iVhItbY9X4JFDhhsZrbQLDPnCyVvh/l+0cs1xOaxASm roQQMksxtjwt7je8hw7ByoNo3g== X-Google-Smtp-Source: APXvYqzrHo6Lx8inQHoBqC92w70TYwWYudny/6+lO98FORxU86UKTPmvJKWhS25QNHxrDMpyvwaiQA== X-Received: by 2002:a63:cd15:: with SMTP id i21mr23171308pgg.453.1580785008498; Mon, 03 Feb 2020 18:56:48 -0800 (PST) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:5bbb:c872:f2b1:f53b]) by smtp.gmail.com with ESMTPSA id e1sm22491971pfl.98.2020.02.03.18.56.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Feb 2020 18:56:47 -0800 (PST) From: Sergey Senozhatsky To: Hans Verkuil , Tomasz Figa , Mauro Carvalho Chehab , Kyungmin Park , Marek Szyprowski Cc: Sakari Ailus , Laurent Pinchart , Pawel Osciak , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky Subject: [RFC][PATCHv2 00/12] Implement V4L2_BUF_FLAG_NO_CACHE_* flags Date: Tue, 4 Feb 2020 11:56:29 +0900 Message-Id: <20200204025641.218376-1-senozhatsky@chromium.org> X-Mailer: git-send-email 2.25.0.341.g760bfbb309-goog MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hello, V2 of the patchset, reshuffled, added more documentation, addressed some of the feedback ;) Still in RFC, tho v1 link: https://lore.kernel.org/lkml/20191217032034.54897-1-senozhatsky@chromium.org/ --- This is a reworked version of the vb2 cache hints (V4L2_BUF_FLAG_NO_CACHE_INVALIDATE / V4L2_BUF_FLAG_NO_CACHE_CLEAN) support patch series which previsouly was developed by Sakari and Laurent [0]. The patch set attempts to preserve the existing behvaiour - cache sync is performed in ->prepare() and ->finish() (unless the buffer is DMA exported). User space can request “default behavior” override with cache management hints, which are handled on a per-buffer basis and should be supplied with v4l2_buffer ->flags during buffer preparation. There are two possible hints: - V4L2_BUF_FLAG_NO_CACHE_INVALIDATE No cache sync on ->finish() - V4L2_BUF_FLAG_NO_CACHE_CLEAN No cache sync on ->prepare() In order to keep things on the safe side, we also require driver to explicitly state which of its queues (if any) support user space cache management hints (such queues should have ->allow_cache_hints bit set). The patch set also (to some extent) simplifies allocators' ->prepare() and ->finish() callbacks. Namely, we move cache management decision making to the upper - core - layer. For example, if, previously, we would have something like this vb2_buffer_done() vb2_dc_finish() if (buf->db_attach) return; where each allocators' ->finish() callback would either bail out (DMA exported buffer, for instance) or sync, now that "bail out or sync" decision is made before we call into the allocator. Along with cache management hints, user space is also able to adjust queue's memory consistency attributes. Memory consistency attribute (dma_attrs) is per-queue, yet it plays its role on the allocator level, when we allocate buffers’ private memory (planes). For the time being, only one consistency attribute is supported: DMA_ATTR_NON_CONSISTENT. [0] https://www.mail-archive.com/linux-media@vger.kernel.org/msg112459.html Sergey Senozhatsky (12): videobuf2: add cache management members videobuf2: handle V4L2 buffer cache flags videobuf2: add V4L2_FLAG_MEMORY_NON_CONSISTENT flag videobuf2: add queue memory consistency parameter videobuf2: handle V4L2_FLAG_MEMORY_NON_CONSISTENT flag videobuf2: factor out planes prepare/finish functions videobuf2: do not sync caches when we are allowed not to videobuf2: check ->synced flag in prepare() and finish() videobuf2: let user-space know if driver supports cache hints videobuf2: add begin/end cpu_access callbacks to dma-contig videobuf2: add begin/end cpu_access callbacks to dma-sg videobuf2: don't test db_attach in dma-contig prepare and finish Documentation/media/uapi/v4l/buffer.rst | 27 +++++ .../media/uapi/v4l/vidioc-create-bufs.rst | 9 +- .../media/uapi/v4l/vidioc-reqbufs.rst | 22 +++- .../media/common/videobuf2/videobuf2-core.c | 110 +++++++++++++----- .../common/videobuf2/videobuf2-dma-contig.c | 39 ++++++- .../media/common/videobuf2/videobuf2-dma-sg.c | 30 +++-- .../media/common/videobuf2/videobuf2-v4l2.c | 59 +++++++++- drivers/media/dvb-core/dvb_vb2.c | 2 +- drivers/media/v4l2-core/v4l2-ioctl.c | 5 +- include/media/videobuf2-core.h | 17 ++- include/uapi/linux/videodev2.h | 11 +- 11 files changed, 273 insertions(+), 58 deletions(-)