From patchwork Tue Dec 17 03:20:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sergey Senozhatsky X-Patchwork-Id: 11296455 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 A54A5112B for ; Tue, 17 Dec 2019 03:20:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 700232465E for ; Tue, 17 Dec 2019 03:20:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="nJg1EkAd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726880AbfLQDUo (ORCPT ); Mon, 16 Dec 2019 22:20:44 -0500 Received: from mail-pg1-f174.google.com ([209.85.215.174]:38392 "EHLO mail-pg1-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725836AbfLQDUo (ORCPT ); Mon, 16 Dec 2019 22:20:44 -0500 Received: by mail-pg1-f174.google.com with SMTP id a33so4855618pgm.5 for ; Mon, 16 Dec 2019 19:20:43 -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=8OIkbBGm2/UIWBdt/4gwjBTwZSPsO7hELscBafMhK08=; b=nJg1EkAd+ybAc6ZVbt6WYAZhn496n6O8pCjF99UpEZqCsit12oo2aWCdEA5q3vCptt DjW3f1lXd8ueQyTxe1kcmll7UpvHQZKpHuaq7b/PGmL5GpRChdp/6n94XfA7LH6YliAF kQvcfuaJ6EdK/iL1qU1n5DtD2dza2rvZjsB2k= 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=8OIkbBGm2/UIWBdt/4gwjBTwZSPsO7hELscBafMhK08=; b=bRmIq5FoGd2/a3KsqwHH6NCLB3xAHOc8A60onyGjy56DVf8a4edNkq1ONeLkKVfqba as1XCExveomSATCVdv6yVJnNYcaJ6LlrlehCobb5VYH6OSvu/WfTkfGKqFvC6jLroggV xLZBTJ1r1kKI0rKJORcki57if0isdw/AHMtV/px1+O50m4hh/tbon8CoujjlgDuLn6qG X6wEUgWyUGHUu5PY61MCQ/bUoZdrRVHOGHOHeooazOdObLy0waxvKVSo5qwANRTg+t+7 aTzSJAdcKtVPCht2zSlkS8QKiBvqKpxBBe5slC52AbNstSwx71QjXAzhRNKPTCMmwjhY G1NQ== X-Gm-Message-State: APjAAAWnoxhezmQohSOK+s2cuGDllDv4lt2DNQvh3BlFtcrPkj2ndbqb LTfA/hgOH9hRY6CrxyUEXjB9nA== X-Google-Smtp-Source: APXvYqy2vER++9HLpfOhE1FDCXib9wTZt6yt1GUjs+8EGFMHkytRVF6m4bcdXYLUJlDpk+/M6P/GuA== X-Received: by 2002:a65:4c82:: with SMTP id m2mr21937460pgt.432.1576552843221; Mon, 16 Dec 2019 19:20:43 -0800 (PST) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:250d:e71d:5a0a:9afe]) by smtp.gmail.com with ESMTPSA id j3sm24387455pfi.8.2019.12.16.19.20.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Dec 2019 19:20:42 -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][PATCH 00/15] Implement V4L2_BUF_FLAG_NO_CACHE_* flags Date: Tue, 17 Dec 2019 12:20:19 +0900 Message-Id: <20191217032034.54897-1-senozhatsky@chromium.org> X-Mailer: git-send-email 2.24.1.735.g03f4e72817-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, RFC 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 (15): 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 in REQBUFS videobuf2: handle V4L2_FLAG_MEMORY_NON_CONSISTENT in CREATE_BUFS 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 when 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: do not sync buffers for DMABUF queues videobuf2: don't test db_attach in dma-contig prepare and finish videobuf2: don't test db_attach in dma-sg prepare and finish Documentation/media/uapi/v4l/buffer.rst | 19 ++++ .../media/uapi/v4l/vidioc-create-bufs.rst | 8 +- .../media/uapi/v4l/vidioc-reqbufs.rst | 19 +++- .../media/common/videobuf2/videobuf2-core.c | 107 +++++++++++++----- .../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, 259 insertions(+), 57 deletions(-)