Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Fri, 30 Nov 2018 11:32:22 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Rui Salvaterra <rsalvaterra@gmail.com>
Cc:     hch@lst.de, linux-kernel@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org
Subject: Re: use generic DMA mapping code in powerpc V4
Message-ID: <20181130103222.GA23393@lst.de>
References: <CALjTZvZzHSZ=s0W0Pd-MVd7OA0hYxu0LzsZ+GxYybXKoUQQR6Q@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CALjTZvZzHSZ=s0W0Pd-MVd7OA0hYxu0LzsZ+GxYybXKoUQQR6Q@mail.gmail.com>
User-Agent: Mutt/1.5.17 (2007-11-01)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Rui,

can you check if the patch below fixes the issue for you?

diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c
index 2e24fc87ed84..809797dbe169 100644
--- a/arch/powerpc/sysdev/dart_iommu.c
+++ b/arch/powerpc/sysdev/dart_iommu.c
@@ -392,7 +392,9 @@ static void pci_dma_dev_setup_dart(struct pci_dev *dev)
 
 static bool iommu_bypass_supported_dart(struct pci_dev *dev, u64 mask)
 {
-	return dart_is_u4 && dart_device_on_pcie(&dev->dev);
+	return dart_is_u4 &&
+		dart_device_on_pcie(&dev->dev) &&
+		mask >= DMA_BIT_MASK(40);
 }
 
 void __init iommu_init_early_dart(struct pci_controller_ops *controller_ops)