From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1034750AbcIZMcy (ORCPT ); Mon, 26 Sep 2016 08:32:54 -0400 Received: from mail-pa0-f41.google.com ([209.85.220.41]:36802 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1034582AbcIZMct (ORCPT ); Mon, 26 Sep 2016 08:32:49 -0400 From: Ard Biesheuvel To: linux-kernel@vger.kernel.org, bskeggs@redhat.com, airlied@linux.ie, dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org Cc: Ard Biesheuvel Subject: [PATCH v4 1/3] drm/nouveau: set streaming DMA mask early Date: Mon, 26 Sep 2016 05:32:38 -0700 Message-Id: <1474893160-12321-2-git-send-email-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1474893160-12321-1-git-send-email-ard.biesheuvel@linaro.org> References: <1474893160-12321-1-git-send-email-ard.biesheuvel@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some subdevices (i.e., fb/nv50.c and fb/gf100.c) map a scratch page using dma_map_page() way before the TTM layer has had a chance to set the DMA mask. This may prevent the driver from loading at all on platforms whose system memory is not covered by the default DMA mask of 32-bit (i.e., when all RAM is above 4 GB). So set a preliminary DMA mask right after constructing the PCI device, and base it on the .dma_bits member of the MMU subdevice, which is what the TTM layer will base the DMA mask on as well. Signed-off-by: Ard Biesheuvel --- drivers/gpu/drm/nouveau/nouveau_drm.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c index 652ab111dd74..e61e9a0adb51 100644 --- a/drivers/gpu/drm/nouveau/nouveau_drm.c +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c @@ -361,6 +361,17 @@ static int nouveau_drm_probe(struct pci_dev *pdev, pci_set_master(pdev); + /* + * Set a preliminary DMA mask based on the .dma_bits member of the + * MMU subdevice. This allows other subdevices to create DMA mappings + * in their init() function, which are called before the TTM layer sets + * the DMA mask definitively. + * This is necessary for platforms where the default DMA mask of 32 + * does not cover any system memory, i.e., when all RAM is > 4 GB. + */ + dma_set_mask_and_coherent(device->dev, + DMA_BIT_MASK(device->mmu->dma_bits)); + ret = drm_get_pci_dev(pdev, pent, &driver_pci); if (ret) { nvkm_device_del(&device); -- 2.7.4