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Commit 2f082b13 authored by Liu Gang's avatar Liu Gang Committed by Shawn Guo
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bindings: PCI: layerscape: Add 'dma-coherent' property 



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: default avatarLiu Gang <Gang.Liu@nxp.com>
Acked-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarShawn Guo <shawnguo@kernel.org>
parent bf26225f

Documentation/devicetree/bindings/pci/layerscape-pci.txt

+4 −0
Original line number Diff line number Diff line
@@ -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 */