Messages in this thread |  | | | From | Thomas Koeller <> | | Subject | Re: DMA using data buffer vmapped in kernel space | | Date | Sat, 6 Mar 2010 14:07:12 +0100 |
| |
Am Donnerstag, 4. März 2010 22:36:34 schrieb Russell King - ARM Linux: > Cache maintainence is done using virtual addresses for L1, and > physical addresses for L2. There's the need for virtual addresses > to be translatable to physical addresses, which is only true for > the kernel direct mapped region (pages between PAGE_OFFSET and > high_memory).
Isn't the mapping created by vmap() sufficient for the virt/phys translation? In which way is this case different from a buffer passed in from user space, where the constituent pages are not in the directly mapped kernel region either?
tk
-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |