From patchwork Mon Mar 2 04:12:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergey Senozhatsky X-Patchwork-Id: 11414743 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 40795930 for ; Mon, 2 Mar 2020 04:12:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1734E246B6 for ; Mon, 2 Mar 2020 04:12:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="LeRfzwHi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727060AbgCBEMm (ORCPT ); Sun, 1 Mar 2020 23:12:42 -0500 Received: from mail-pl1-f194.google.com ([209.85.214.194]:44686 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726876AbgCBEMm (ORCPT ); Sun, 1 Mar 2020 23:12:42 -0500 Received: by mail-pl1-f194.google.com with SMTP id d9so3652961plo.11 for ; Sun, 01 Mar 2020 20:12:41 -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:in-reply-to:references :mime-version:content-transfer-encoding; bh=CoetZS9vuxTZ+PyAPLZRJLnoTD2MnEuUAYGHdJwiBqs=; b=LeRfzwHi8oJoYEV2ftWQe6u50EWhhQZErNapDPcIjTb+Sd6R+fd6x2IjxUt+XQhNf8 j3ZI4/4J3cIKXc7PaiH6lBD/2Pp+QwBfngL7jp79eovCh7kgZhzCiYbhKnbAVb5NPsbJ F0Ds2wnMtOJjpW89Q27zB3LGw0t3dUbPoNZ98= 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=CoetZS9vuxTZ+PyAPLZRJLnoTD2MnEuUAYGHdJwiBqs=; b=jDT5TyExsuHOaViN1hL2LsOHLtMD91NOo3OEhS3Im5A840Xtqp0wtObqEiCUQ6HzEO KSP4y2D2ymncR9ikW+xptaRUkpJ13ztwNYxwxqKWsuMOHa1myIwQZJDULONEDwjSQ7Lm mngfp7L46ml6jIQuD3K0qHqKRUpmyy746Nx32jUNGHmjwB72FV+XYkqYt1v4PDgqXN6N yupss444U3KxuezDFbv/piYpwgegyP8XGD4TfwyYlmz4/MziWrcjBgywsOciGCnSxgxY eL9B9LTSxIq1zIcQWV+Erz0rWVPPPrOT+kamqf0LjbZfSxjoWhPr8J2DICViopK1ibFk Vs1g== X-Gm-Message-State: APjAAAVaP9wHHj402ojADTNQIyqK1b0gKVwXmQ8yGaRG04CoguXyIHYf xJaEKmqknN+Xqjpn/KQwYfy24A== X-Google-Smtp-Source: APXvYqwY5WpLZv1Aq5NZ/mOTGi+TcrYj2pNF50u0UD6ple9/IyZ6BApso8aJfGPcuzqnCQ/dbUaULQ== X-Received: by 2002:a17:90a:a88d:: with SMTP id h13mr17972603pjq.55.1583122360698; Sun, 01 Mar 2020 20:12:40 -0800 (PST) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:5bbb:c872:f2b1:f53b]) by smtp.gmail.com with ESMTPSA id d82sm1698114pfd.187.2020.03.01.20.12.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 01 Mar 2020 20:12:40 -0800 (PST) From: Sergey Senozhatsky To: Hans Verkuil , Tomasz Figa Cc: Mauro Carvalho Chehab , Kyungmin Park , Marek Szyprowski , Sakari Ailus , Laurent Pinchart , Pawel Osciak , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky Subject: [PATCHv4 03/11] videobuf2: add V4L2_FLAG_MEMORY_NON_CONSISTENT flag Date: Mon, 2 Mar 2020 13:12:05 +0900 Message-Id: <20200302041213.27662-4-senozhatsky@chromium.org> X-Mailer: git-send-email 2.25.0.265.gbab2e86ba0-goog In-Reply-To: <20200302041213.27662-1-senozhatsky@chromium.org> References: <20200302041213.27662-1-senozhatsky@chromium.org> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org By setting or clearing V4L2_FLAG_MEMORY_NON_CONSISTENT flag user-space should be able to set or clear queue's NON_CONSISTENT ->dma_attrs. Queue's ->dma_attrs are passed to the underlying allocator in __vb2_buf_mem_alloc(), so thus user-space is able to request vb2 buffer's memory to be either consistent (coherent) or non-consistent. The patch set also adds a corresponding capability flag: fill_buf_caps() reports V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS when queue supports user-space cache management hints. Signed-off-by: Sergey Senozhatsky --- Documentation/media/uapi/v4l/buffer.rst | 29 +++++++++++++++++++ .../media/uapi/v4l/vidioc-reqbufs.rst | 7 +++++ .../media/common/videobuf2/videobuf2-v4l2.c | 2 ++ include/uapi/linux/videodev2.h | 3 ++ 4 files changed, 41 insertions(+) diff --git a/Documentation/media/uapi/v4l/buffer.rst b/Documentation/media/uapi/v4l/buffer.rst index 3112300c2fa0..8084e3f2a58d 100644 --- a/Documentation/media/uapi/v4l/buffer.rst +++ b/Documentation/media/uapi/v4l/buffer.rst @@ -681,6 +681,35 @@ Buffer Flags \normalsize +.. _memory-flags: + +Memory Consistency Flags +======================== + +.. tabularcolumns:: |p{7.0cm}|p{2.2cm}|p{8.3cm}| + +.. cssclass:: longtable + +.. flat-table:: + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 4 + + * .. _`V4L2_FLAG_MEMORY_NON_CONSISTENT`: + + - ``V4L2_FLAG_MEMORY_NON_CONSISTENT`` + - 0x00000001 + - A buffer is allocated either in consistent (it will be automatically + coherent between the CPU and the bus) or non-consistent memory. The + latter can provide performance gains, for instance the CPU cache + sync/flush operations can be avoided if the buffer is accessed by the + corresponding device only and the CPU does not read/write to/from that + buffer. However, this requires extra care from the driver -- it must + guarantee memory consistency by issuing a cache flush/sync when + consistency is needed. If this flag is set V4L2 will attempt to + allocate the buffer in non-consistent memory. The flag takes effect + only if the buffer is used for :ref:`memory mapping ` I/O and the + queue reports the :ref:`V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS` capability. .. c:type:: v4l2_memory diff --git a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst index d0c643db477a..21ecacc72487 100644 --- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst +++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst @@ -156,6 +156,13 @@ aborting or finishing any DMA in progress, an implicit - Only valid for stateless decoders. If set, then userspace can set the ``V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF`` flag to hold off on returning the capture buffer until the OUTPUT timestamp changes. + * - ``V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS`` + - 0x00000040 + - Set when the queue/buffer supports memory consistency and cache + management hints. See :ref:`V4L2_FLAG_MEMORY_NON_CONSISTENT`, + :ref:`V4L2_BUF_FLAG_NO_CACHE_INVALIDATE` and + :ref:`V4L2_BUF_FLAG_NO_CACHE_CLEAN`. + Return Value ============ diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index 2a604bd7793a..c847bcea6e95 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -711,6 +711,8 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps) *caps |= V4L2_BUF_CAP_SUPPORTS_DMABUF; if (q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF) *caps |= V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF; + if (q->allow_cache_hints && (q->io_modes & VB2_MMAP)) + *caps |= V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS; #ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API if (q->supports_requests) *caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS; diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 5f9357dcb060..e92c29864730 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -189,6 +189,8 @@ enum v4l2_memory { V4L2_MEMORY_DMABUF = 4, }; +#define V4L2_FLAG_MEMORY_NON_CONSISTENT (1 << 0) + /* see also http://vektor.theorem.ca/graphics/ycbcr/ */ enum v4l2_colorspace { /* @@ -946,6 +948,7 @@ struct v4l2_requestbuffers { #define V4L2_BUF_CAP_SUPPORTS_REQUESTS (1 << 3) #define V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS (1 << 4) #define V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF (1 << 5) +#define V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS (1 << 6) /** * struct v4l2_plane - plane info for multi-planar buffers