Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754845AbdGJWXl (ORCPT ); Mon, 10 Jul 2017 18:23:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:46540 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754041AbdGJWXj (ORCPT ); Mon, 10 Jul 2017 18:23:39 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6B5B322BD0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=helgaas@kernel.org Date: Mon, 10 Jul 2017 17:23:35 -0500 From: Bjorn Helgaas To: Christian =?iso-8859-1?Q?K=F6nig?= Cc: linux-pci@vger.kernel.org, dri-devel@lists.freedesktop.org, platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org Subject: Re: [PATCH v8 6/6] drm/amdgpu: resize VRAM BAR for CPU access v4 Message-ID: <20170710222335.GG5610@bhelgaas-glaptop.roam.corp.google.com> References: <1499698794-1718-1-git-send-email-deathsimple@vodafone.de> <1499698794-1718-7-git-send-email-deathsimple@vodafone.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1499698794-1718-7-git-send-email-deathsimple@vodafone.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4628 Lines: 120 On Mon, Jul 10, 2017 at 04:59:54PM +0200, Christian K?nig wrote: > From: Christian K?nig > > Try to resize BAR0 to let CPU access all of VRAM. > > v2: rebased, style cleanups, disable mem decode before resize, > handle gmc_v9 as well, round size up to power of two. > v3: handle gmc_v6 as well, release and reassign all BARs in the driver. > v4: rename new function to amdgpu_device_resize_fb_bar, > reenable mem decoding only if all resources are assigned. > > Signed-off-by: Christian K?nig > --- > drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 + > drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 46 ++++++++++++++++++++++++++++++ > drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c | 8 ++++-- > drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c | 8 ++++-- > drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c | 8 ++++-- > drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c | 10 ++++--- > 6 files changed, 68 insertions(+), 13 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h > index ff7bf1a..5809e0e 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h > @@ -1944,6 +1944,7 @@ uint64_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt *ttm, > struct ttm_mem_reg *mem); > void amdgpu_vram_location(struct amdgpu_device *adev, struct amdgpu_mc *mc, u64 base); > void amdgpu_gtt_location(struct amdgpu_device *adev, struct amdgpu_mc *mc); > +void amdgpu_device_resize_fb_bar(struct amdgpu_device *adev); > void amdgpu_ttm_set_active_vram_size(struct amdgpu_device *adev, u64 size); > int amdgpu_ttm_init(struct amdgpu_device *adev); > void amdgpu_ttm_fini(struct amdgpu_device *adev); > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > index 7d1a04a..a5123f5 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > @@ -428,6 +428,9 @@ static int amdgpu_doorbell_init(struct amdgpu_device *adev) > return 0; > } > > + if (pci_resource_flags(adev->pdev, 2) & IORESOURCE_UNSET) > + return -EINVAL; > + > /* doorbell bar mapping */ > adev->doorbell.base = pci_resource_start(adev->pdev, 2); > adev->doorbell.size = pci_resource_len(adev->pdev, 2); > @@ -709,6 +712,49 @@ void amdgpu_gtt_location(struct amdgpu_device *adev, struct amdgpu_mc *mc) > mc->gtt_size >> 20, mc->gtt_start, mc->gtt_end); > } > > +/** > + * amdgpu_device_resize_fb_bar - try to resize FB BAR > + * > + * @adev: amdgpu_device pointer > + * > + * Try to resize FB BAR to make all VRAM CPU accessible. > + */ > +void amdgpu_device_resize_fb_bar(struct amdgpu_device *adev) > +{ > + u64 space_needed = roundup_pow_of_two(adev->mc.real_vram_size); > + u32 rbar_size = order_base_2(((space_needed >> 20) | 1)) - 1; > + u16 cmd; > + int r; > + > + /* Disable memory decoding while we change the BAR addresses and size */ > + pci_read_config_word(adev->pdev, PCI_COMMAND, &cmd); > + pci_write_config_word(adev->pdev, PCI_COMMAND, > + cmd & ~PCI_COMMAND_MEMORY); > + > + /* Free the VRAM and doorbell BAR, we most likely need to move both. */ > + amdgpu_doorbell_fini(adev); > + pci_release_resource(adev->pdev, 0); > + if (adev->asic_type >= CHIP_BONAIRE) > + pci_release_resource(adev->pdev, 2); The related pieces should be together, e.g., amdgpu_doorbell_fini(adev); if (adev->asic_type >= CHIP_BONAIRE) pci_release_resource(adev->pdev, 2); pci_release_resource(adev->pdev, 0); > + r = pci_resize_resource(adev->pdev, 0, rbar_size); > + if (r == -ENOSPC) > + DRM_INFO("Not enough PCI address space for a large BAR."); > + else if (r && r != -ENOTSUPP) > + DRM_ERROR("Problem resizing BAR0 (%d).", r); > + > + pci_assign_unassigned_bus_resources(adev->pdev->bus); > + > + /* When the doorbell or fb BAR isn't available we have no chance of > + * using the device. > + */ > + r = amdgpu_doorbell_init(adev); > + if ((pci_resource_flags(adev->pdev, 0) & IORESOURCE_UNSET) || r) > + BUG(); Seems extreme to panic the system in this case. I don't think IORESOURCE_UNSET should appear in a driver. I think that's an internal property that should be handled in the core. What if you added something like this: int pci_enable_mem_decoding(struct pci_dev *dev) { unsigned int bars = 0; for (i = 0; i <= PCI_ROM_RESOURCE; i++) if (dev->resource[i].flags & IORESOURCE_MEM) bars |= (1 << i); return pci_enable_resources(pdev, bars); } > + else > + pci_write_config_word(adev->pdev, PCI_COMMAND, cmd); > +}