From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liu Gang Subject: [PATCH] PCI: layerscape: Add 'dma-coherent' property Date: Tue, 7 Jun 2016 14:55:45 +0800 Message-ID: <1465282546-28256-1-git-send-email-Gang.Liu@nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, shawnguo@kernel.org, robh@kernel.org Cc: minghuan.lian@nxp.com, Liu Gang , leoyang.li@nxp.com, mingkai.hu@nxp.com, scott.wood@nxp.com List-Id: devicetree@vger.kernel.org Add 'dma-coherent' description for PCI nodes. The 'dma-coherent' indicates that the hardware IP block can ensure the coherency of the data transferred from/to the IP block. This can avoid the software cache flush/invalid actions, and improve the performance significantly. The PCI IP block of ls1043a has this capability, so adding this feature to improve the PCI performance. Signed-off-by: Liu Gang --- Documentation/devicetree/bindings/pci/layerscape-pci.txt | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Documentation/devicetree/bindings/pci/layerscape-pci.txt b/Documentation/devicetree/bindings/pci/layerscape-pci.txt index ef683b2..41e9f55 100644 --- a/Documentation/devicetree/bindings/pci/layerscape-pci.txt +++ b/Documentation/devicetree/bindings/pci/layerscape-pci.txt @@ -24,6 +24,9 @@ Required properties: The first entry must be a link to the SCFG device node The second entry must be '0' or '1' based on physical PCIe controller index. This is used to get SCFG PEXN registers +- dma-coherent: Indicates that the hardware IP block can ensure the coherency + of the data transferred from/to the IP block. This can avoid the software + cache flush/invalid actions, and improve the performance significantly. Example: @@ -38,6 +41,7 @@ Example: #address-cells = <3>; #size-cells = <2>; device_type = "pci"; + dma-coherent; num-lanes = <4>; bus-range = <0x0 0xff>; ranges = <0x81000000 0x0 0x00000000 0x40 0x00010000 0x0 0x00010000 /* downstream I/O */ -- 2.1.0.27.g96db324