[PATCH 1/1] arm/dts: Tegra30: Add device tree support for SMMU

Arnd Bergmann arnd at arndb.de
Tue Apr 17 01:34:19 EST 2012


On Monday 16 April 2012, Hiroshi Doyu wrote:
> What about using "dma-window" property to specify IOVA range in dtsi as below?
> 
> arch/powerpc/platforms/cell/iommu.c:
> 
> 698 static int __init cell_iommu_get_window(struct device_node *np,
> 699                                          unsigned long *base,
> 700                                          unsigned long *size)
> 701 {
> 702         const void *dma_window;
> 703         unsigned long index;
> 704
> 705         /* Use ibm,dma-window if available, else, hard code ! */
> 706         dma_window = of_get_property(np, "ibm,dma-window", NULL);
> 707         if (dma_window == NULL) {          ^^^^^^^^^^^^^^
> 708                 *base = 0;
> 709                 *size = 0x80000000u;
> 710                 return -ENODEV;
> 711         }
> 712
> 713         of_parse_dma_window(np, dma_window, &index, base, size);
> 714         return 0;
> 715 }
> 

Yes, that's the right way to do it, but I would use the more generic
"dma-window" name rather than "ibm,dma-window", which was originally
introduced for pseries and for some reason copied into the cell qs2x
firmware.

	Arnd


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