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 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2F9EFFCC9AD for ; Tue, 10 Mar 2026 03:25:51 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9104610E632; Tue, 10 Mar 2026 03:25:50 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.b="TXXPFpJ3"; dkim-atps=neutral Received: from mail-pl1-f181.google.com (mail-pl1-f181.google.com [209.85.214.181]) by gabe.freedesktop.org (Postfix) with ESMTPS id CFEDB10E633 for ; Tue, 10 Mar 2026 03:25:48 +0000 (UTC) Received: by mail-pl1-f181.google.com with SMTP id d9443c01a7336-2ab46931cf1so84671925ad.0 for ; Mon, 09 Mar 2026 20:25:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1773113148; x=1773717948; darn=lists.freedesktop.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=9DNho1J2CisM3xAD9Y1bBejtF+SOOT6CZm5ayFQyPks=; b=TXXPFpJ3I5rWi6NUSQkJE65U04DaBU7gufKijQ88otIBUKd+uIJkIGCMoEiLLVDtEC x94N074KuYy5nYsLdAIycN4UGADSam55ziKE/2jBtk4seLbRxhecMDWSnmWrYUNUVV6B Il2/kEo4MwdIvJZibz7adDlH6Jccp1Pl9SIJs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1773113148; x=1773717948; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=9DNho1J2CisM3xAD9Y1bBejtF+SOOT6CZm5ayFQyPks=; b=DQw/JPyD+xHVdqCW7gewAolB8Nof72TkpFyP/Jw+kfe+XY1mbFm6CKN22NxpAkMda+ uqs2Giil+c1l7mupzFt82OWOvu8IKfyFYNjC80eN0rO03i8pDLsNFehpvUXJoxP9yDLQ EdxFJyL+FURZVnhvD/17pTqSFeaEADKWrXd+zoZ5dv05YbknWRZt9BoiRnYduGwU9Fox aM0XXKdWQykCda9vwl1H9FwtKttv2YN1lcr+CuUTQ28/IbVx4/jlMC8f2IsZWRAmfZwc +KFjcMgPTjHtkuqUW4he6z04s9p7DDH66zRzyQzdHc2Vrpvs46U+D736YTc0u2dLvE34 pRmw== X-Forwarded-Encrypted: i=1; AJvYcCVTn0tpzMkeHIzXbclgSavaGL6XMcLJuNAupmkz0X8DDTi9hLT1b3/VWXLq0nFhucQIdE+2LQXOxkU=@lists.freedesktop.org X-Gm-Message-State: AOJu0YzkwdhZytTngI6vKzyp3wIT+m4CkswQNaEUEV7ysS3f2bl75eYC pvYAqXqTkIjJ9aZT3qRbfgfIppn3hhqIG2MrUATVuYuIFKlS6OsiiamOHmYq4XGf1Q== X-Gm-Gg: ATEYQzxQB8JI6Q4ZffLAKY4hBM3WkSRBZxtMt3Cbcgy4fMRVfV38dSwhmZ4hyv3V9k/ U157K8sx0qxOvB61viLH5QvCPh6Btko6uvuMJS+en+bLF6Zyfwuv8xo/UJBEnxGYGApH06SatBd 6dvDNthyfo+GSvItpCf5Dvi2VsEzFo5tlqW96WEvsMI6s6dP/7lIqgEtQNSrJBdD3V035lz/3J8 hV2xihFWpXUXiJPWi++5+4ysvLWhl6GxuQteiwJpn6cVrPXclZMrQXk5Ilq4j2oN/HC2jSk6Og2 Ku2081i/HOT5trysaTwOj9PsqrXevh8QHRVQO2KIrupI7cbSLUMMKhoY0bPAvIKEfoGLJH5hvcw D1rC3QHouIIN6b/zXDc31HFyjOfXuCtMWmrwUuR1l6NMflZmWTCB+QAZKXO2fNnTo+1ucnc4cqB HLG+NHHKa4NNMM6NlTselN88AnZ7GLh9b3tBQE55IgZ4vuCt6fQz73ABVRQLEMAkFmY/2b0rrlU LI/Y5OSz/I0qorujiI= X-Received: by 2002:a17:902:da2d:b0:2a7:aac1:7201 with SMTP id d9443c01a7336-2aea197b887mr18842765ad.3.1773113148339; Mon, 09 Mar 2026 20:25:48 -0700 (PDT) Received: from wenstp920.tpe.corp.google.com ([2a00:79e0:201d:8:ee38:e01e:e888:6900]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2ae83e575e6sm126695095ad.5.2026.03.09.20.25.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Mar 2026 20:25:47 -0700 (PDT) From: Chen-Yu Tsai To: Matthias Brugger , AngeloGioacchino Del Regno , Chun-Kuang Hu , Philipp Zabel , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , David Airlie , Simona Vetter Cc: Chen-Yu Tsai , linux-sunxi@lists.linux.dev, Paul Kocialkowski , linux-mediatek@lists.infradead.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH RESEND 2/4] drm/gem-dma: Support dedicated DMA device for allocation and mapping Date: Tue, 10 Mar 2026 11:25:07 +0800 Message-ID: <20260310032511.2545500-3-wenst@chromium.org> X-Mailer: git-send-email 2.53.0.473.g4a7958ca14-goog In-Reply-To: <20260310032511.2545500-1-wenst@chromium.org> References: <20260310032511.2545500-1-wenst@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Support for a dedicated DMA device for prime imports was added in commit 143ec8d3f939 ("drm/prime: Support dedicated DMA device for dma-buf imports"). This allowed the DRM driver to provide a dedicated DMA device when its own underlying device was not capable of DMA, for example when it is a USB device (the original target) or a virtual device. The latter case is common on embedded SoCs, on which the display pipeline is composed of various fixed function blocks, and the DRM device is simply a made-up device, an address space managing the routing between the blocks, or whichever block the implementor thought made sense at the time. The point is that the chosen device is often not the actual device doing the DMA. Various drivers have used workarounds or reimplemented the GEM DMA helpers to get the DMA addresses and IOMMUs to work correctly. Add support for the dedicated DMA device to the GEM DMA helpers. No existing driver currently uses the GEM DMA helpers and calls drm_dev_set_dma_dev() to set a dedicated DMA device, so no existing users should be affected. Signed-off-by: Chen-Yu Tsai --- drivers/gpu/drm/drm_gem_dma_helper.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/drm_gem_dma_helper.c b/drivers/gpu/drm/drm_gem_dma_helper.c index ecb9746f4da8..70f83e464476 100644 --- a/drivers/gpu/drm/drm_gem_dma_helper.c +++ b/drivers/gpu/drm/drm_gem_dma_helper.c @@ -146,12 +146,13 @@ struct drm_gem_dma_object *drm_gem_dma_create(struct drm_device *drm, return dma_obj; if (dma_obj->map_noncoherent) { - dma_obj->vaddr = dma_alloc_noncoherent(drm->dev, size, + dma_obj->vaddr = dma_alloc_noncoherent(drm_dev_dma_dev(drm), + size, &dma_obj->dma_addr, DMA_TO_DEVICE, GFP_KERNEL | __GFP_NOWARN); } else { - dma_obj->vaddr = dma_alloc_wc(drm->dev, size, + dma_obj->vaddr = dma_alloc_wc(drm_dev_dma_dev(drm), size, &dma_obj->dma_addr, GFP_KERNEL | __GFP_NOWARN); } @@ -236,12 +237,14 @@ void drm_gem_dma_free(struct drm_gem_dma_object *dma_obj) drm_prime_gem_destroy(gem_obj, dma_obj->sgt); } else if (dma_obj->vaddr) { if (dma_obj->map_noncoherent) - dma_free_noncoherent(gem_obj->dev->dev, dma_obj->base.size, + dma_free_noncoherent(drm_dev_dma_dev(gem_obj->dev), + dma_obj->base.size, dma_obj->vaddr, dma_obj->dma_addr, DMA_TO_DEVICE); else - dma_free_wc(gem_obj->dev->dev, dma_obj->base.size, - dma_obj->vaddr, dma_obj->dma_addr); + dma_free_wc(drm_dev_dma_dev(gem_obj->dev), + dma_obj->base.size, dma_obj->vaddr, + dma_obj->dma_addr); } drm_gem_object_release(gem_obj); @@ -432,7 +435,7 @@ struct sg_table *drm_gem_dma_get_sg_table(struct drm_gem_dma_object *dma_obj) if (!sgt) return ERR_PTR(-ENOMEM); - ret = dma_get_sgtable(obj->dev->dev, sgt, dma_obj->vaddr, + ret = dma_get_sgtable(drm_dev_dma_dev(obj->dev), sgt, dma_obj->vaddr, dma_obj->dma_addr, obj->size); if (ret < 0) goto out; @@ -539,12 +542,12 @@ int drm_gem_dma_mmap(struct drm_gem_dma_object *dma_obj, struct vm_area_struct * if (dma_obj->map_noncoherent) { vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); - ret = dma_mmap_pages(dma_obj->base.dev->dev, + ret = dma_mmap_pages(drm_dev_dma_dev(dma_obj->base.dev), vma, vma->vm_end - vma->vm_start, virt_to_page(dma_obj->vaddr)); } else { - ret = dma_mmap_wc(dma_obj->base.dev->dev, vma, dma_obj->vaddr, - dma_obj->dma_addr, + ret = dma_mmap_wc(drm_dev_dma_dev(dma_obj->base.dev), vma, + dma_obj->vaddr, dma_obj->dma_addr, vma->vm_end - vma->vm_start); } if (ret) -- 2.53.0.473.g4a7958ca14-goog