Hello, On Thu, May 19, 2011 at 3:19 AM, Shaohua Li <shaohua.li@xxxxxxxxx> wrote: > On Wed, 2011-05-18 at 21:02 +0800, Leon Woestenberg wrote: > why use pci_alloc_consistent? you can allocate pages and mmap it to > userspace. when you want to do dma, you can use pci_map_page to get dma > address for the pages and do whatever. > Thanks for thinking along. I need contiguous memory in this case. But yes, I have just found out that __get_free_pages() with pci_map_single() does work with my mmap() fault() handler. See my other thread with the code posted. I just want to understand how this would work with pci_alloc_consistent(), as that is the generic interface for PCI drivers. Note that the latter provides consistent / coherent mapping, whereas pci_map_single() does not in general. On x86 it probably is the same due to bus-snooping (right?). Regards, -- Leon -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>