Fwd: DMA sync operation on user space address

From: Kallol Biswas
Date: Sat Aug 01 2009 - 17:36:30 EST


---------- Forwarded message ----------
From: Kallol Biswas <nucleodyne@xxxxxxxxx>
Date: Fri, Jul 31, 2009 at 10:47 AM
Subject: DMA sync operation on user space address
To: linux-arm@xxxxxxxxxxxxxxx


 I need to implement a DMA sync (flush and invalidate) operation on
user space address.

It seems that the routine blk_dma_flush_range() that is defined in
arch/arm/mm/blockops.c can do the sync operation. Also the function
takes virtual address.

Need to consult an ARM acrh manual to find out if the processor uses
virtual addresses to access the cache. It seems so.

The question is will there be protection or any other issue calling
the above routine from kernel space while the address used as argument
is a user space address?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/