From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0DCD4C4338F for ; Fri, 30 Jul 2021 14:15:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DFFDD60EBB for ; Fri, 30 Jul 2021 14:15:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239089AbhG3OPt (ORCPT ); Fri, 30 Jul 2021 10:15:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230260AbhG3OPs (ORCPT ); Fri, 30 Jul 2021 10:15:48 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF11DC06175F; Fri, 30 Jul 2021 07:15:43 -0700 (PDT) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 6781D89B; Fri, 30 Jul 2021 16:15:42 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1627654542; bh=I47/3VgnbXDDTIxk3lXwXPjZ50+PwFOgzhoG7cS9jUY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Hoihlif92s/+4pHa9zbrQOZGtGmOIOA81C5y4AgRo8WWejrzKMdovNILAowQ1SwPh xt6mLCeg85ZUe6U/LKoFHcnhxX3W5tJ3cZH7lMmdIWISk4ADJBoRY3dk/ZS5L6E0Jv yh4wXhbh6prTrhdnmukb6REPJVZsUXPrBAibL8aE= Date: Fri, 30 Jul 2021 17:15:34 +0300 From: Laurent Pinchart To: Dafna Hirschfeld Cc: linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Helen Koike , Shuah Khan Subject: Re: [PATCH] media: vimc: Add support for contiguous DMA buffers Message-ID: References: <20210730001939.30769-1-laurent.pinchart+renesas@ideasonboard.com> <40a1fed8-456e-97c5-9aa7-715a4a4c816b@collabora.com> <69e4b3fe-5e31-840a-9ea6-a3050f9a6a20@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <69e4b3fe-5e31-840a-9ea6-a3050f9a6a20@collabora.com> Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org Hi Dafna, On Fri, Jul 30, 2021 at 04:08:11PM +0200, Dafna Hirschfeld wrote: > On 30.07.21 15:11, Laurent Pinchart wrote: > > On Fri, Jul 30, 2021 at 02:35:20PM +0200, Dafna Hirschfeld wrote: > >> On 30.07.21 02:19, Laurent Pinchart wrote: > >>> The vimc driver is used for testing purpose, and some test use cases > >>> involve sharing buffers with a consumer device. Consumers often require > >>> DMA contiguous memory, which vimc doesn't currently support. This leads > >>> in the best case to usage of bounce buffers, which is very slow, and in > >>> the worst case in a complete failure. > >>> > >>> Add support for the dma-contig allocator in vimc to support those use > >>> cases properly. The allocator is selected through a new "allocator" > >>> module parameter, which defaults to vmalloc. > >>> > >>> Signed-off-by: Laurent Pinchart > >>> --- > >>> drivers/media/test-drivers/vimc/vimc-capture.c | 9 +++++++-- > >>> drivers/media/test-drivers/vimc/vimc-common.h | 2 ++ > >>> drivers/media/test-drivers/vimc/vimc-core.c | 10 ++++++++++ > >>> 3 files changed, 19 insertions(+), 2 deletions(-) > >>> > >>> diff --git a/drivers/media/test-drivers/vimc/vimc-capture.c b/drivers/media/test-drivers/vimc/vimc-capture.c > >>> index 5e9fd902cd37..92b69a6529fb 100644 > >>> --- a/drivers/media/test-drivers/vimc/vimc-capture.c > >>> +++ b/drivers/media/test-drivers/vimc/vimc-capture.c > >>> @@ -7,6 +7,7 @@ > >>> > >>> #include > >>> #include > >>> +#include > >>> #include > >>> > >>> #include "vimc-common.h" > >>> @@ -423,14 +424,18 @@ static struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc, > >>> /* Initialize the vb2 queue */ > >>> q = &vcap->queue; > >>> q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE; > >>> - q->io_modes = VB2_MMAP | VB2_DMABUF | VB2_USERPTR; > >>> + q->io_modes = VB2_MMAP | VB2_DMABUF; > >> > >> maybe to be on the safe side VB2_DMABUF should be set only if vimc_allocator==1 ? > > > > Why so ? vb2-vmalloc can import dma-bufs. > > oh, I meant that exporting should not be supported. > I see that vimc set ".vidioc_expbuf = vb2_ioctl_expbuf", maybe remove that if allocator is vmalloc? If the importer support non-contiguous buffers, vb2-vmalloc can be used as an exporter. I've successfully used this to test sharing buffers between vimc in vmalloc mode and the R-Car H3 display driver with an IOMMU. > >>> + if (vimc_allocator != 1) > >> > >> maybe define a macro instead of `1` ? > > > > Good idea. > > > >>> + q->io_modes |= VB2_USERPTR; > >>> q->drv_priv = vcap; > >>> q->buf_struct_size = sizeof(struct vimc_cap_buffer); > >>> q->ops = &vimc_cap_qops; > >>> - q->mem_ops = &vb2_vmalloc_memops; > >>> + q->mem_ops = vimc_allocator == 1 > >>> + ? &vb2_dma_contig_memops : &vb2_vmalloc_memops; > >>> q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; > >>> q->min_buffers_needed = 2; > >>> q->lock = &vcap->lock; > >>> + q->dev = v4l2_dev->dev; > >>> > >>> ret = vb2_queue_init(q); > >>> if (ret) { > >>> diff --git a/drivers/media/test-drivers/vimc/vimc-common.h b/drivers/media/test-drivers/vimc/vimc-common.h > >>> index a289434e75ba..b77939123501 100644 > >>> --- a/drivers/media/test-drivers/vimc/vimc-common.h > >>> +++ b/drivers/media/test-drivers/vimc/vimc-common.h > >>> @@ -35,6 +35,8 @@ > >>> > >>> #define VIMC_PIX_FMT_MAX_CODES 8 > >>> > >>> +extern unsigned int vimc_allocator; > >>> + > >>> /** > >>> * vimc_colorimetry_clamp - Adjust colorimetry parameters > >>> * > >>> diff --git a/drivers/media/test-drivers/vimc/vimc-core.c b/drivers/media/test-drivers/vimc/vimc-core.c > >>> index 4b0ae6f51d76..7badcecb7aed 100644 > >>> --- a/drivers/media/test-drivers/vimc/vimc-core.c > >>> +++ b/drivers/media/test-drivers/vimc/vimc-core.c > >>> @@ -5,6 +5,7 @@ > >>> * Copyright (C) 2015-2017 Helen Koike > >>> */ > >>> > >>> +#include > >>> #include > >>> #include > >>> #include > >>> @@ -15,6 +16,12 @@ > >>> > >>> #include "vimc-common.h" > >>> > >>> +unsigned int vimc_allocator; > >>> +module_param_named(allocator, vimc_allocator, uint, 0444); > >>> +MODULE_PARM_DESC(allocator, " memory allocator selection, default is 0.\n" > >>> + "\t\t 0 == vmalloc\n" > >>> + "\t\t 1 == dma-contig"); > >>> + > >> > >> There is a section 'Module options' in vimc.rst. So a doc should be added there. > > > > OK, I'll update that. > > > >>> #define VIMC_MDEV_MODEL_NAME "VIMC MDEV" > >>> > >>> #define VIMC_ENT_LINK(src, srcpad, sink, sinkpad, link_flags) { \ > >>> @@ -278,6 +285,9 @@ static int vimc_probe(struct platform_device *pdev) > >>> > >>> tpg_set_font(font->data); > >>> > >>> + if (vimc_allocator == 1) > >>> + dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); > >>> + > >>> vimc = kzalloc(sizeof(*vimc), GFP_KERNEL); > >>> if (!vimc) > >>> return -ENOMEM; > >>> -- Regards, Laurent Pinchart