On Mon, Mar 9, 2015 at 11:46 PM, Yingjoe Chen <yingjoe.chen@xxxxxxxxxxxx> wrote: > On Mon, 2015-03-09 at 20:11 +0900, Tomasz Figa wrote: > <...> >> > +/* >> > + * pimudev is a global var for dma_alloc_coherent. >> > + * It is not accepatable, we will delete it if "domain_alloc" is enabled >> > + */ >> > +static struct device *pimudev; >> >> This is indeed not acceptable. Could you replace dma_alloc_coherent() >> with something that doesn't require device pointer, e.g. >> alloc_pages()? (Although that would require you to handle cache >> maintenance in the driver, due to cached memory allocated.) I need to >> think about a better solution for this. > > Hi, > > For 2nd level page table, we use cached memory now. Currently we are > using __dma_flush_range to flush the cache, which is also unacceptable. > > For proper cache management, we'll need to use dma_map_single or > dma_sync_*, which still need a deivce*. Looking at how already mainlined drivers do this, they either use dmac_flush_range() (https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/iommu/msm_iommu.c?id=refs/tags/v4.0-rc3#n80) or directly __cpuc_flush_dcache_area() and outer_flush_range() (https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/iommu/rockchip-iommu.c?id=refs/tags/v4.0-rc3#n93). Joerg, what's your opinion on this? Best regards, Tomasz -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
