On Tue, 2015-07-21 at 14:39 -0600, Toshi Kani wrote: > On Tue, 2015-07-21 at 08:17 -0700, Ashutosh Dixit wrote: > > On Mon, Jul 20 2015 at 12:21:18 PM, Toshi Kani <toshi.k...@hp.com>
: > > Yes, you are correct, the 'struct page' pointer returned by > > vmalloc_to_page does not point to a "real" struct page entry. Neither > > have we allocated a struct page for the range. However, because we pass > > the returned pointer to streaming DMA mapping API's > > (dma_map_ops->dma_map_sg or dma_map_ops->dma_map_page) and all those > > functions do is call page_to_phys, they only care about the physical > > address, it used to work. > > > > Would it be possible to have a different API which can do this or can > > vmalloc_to_page be updated to handle huge ioremaps without crashing? > > Or > > would you have a suggestion for doing this differently? > > You can do the following instead. If you have the physical address > already > (i.e. the address you passed to ioremap), you can skip > slow_virt_to_phys(). > pfn_to_page() is a hack for the time being so that you can use the same > DMA mapping APIs. > > phys = slow_virt_to_phys(vaddr); > page = pfn_to_page(phys >> PAGE_SHIFT); Forgot to mention. slow_virt_to_phys() is only defined in x86, but I think your driver is x86-only. Let me know if this is a problem. Thanks, -Toshi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
