Messages in this thread | | | Date | Fri, 05 Nov 1999 22:30:27 -0500 | From | Douglas Gilbert <> | Subject | Re: map_user_kiobuf question |
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> What type of address gets passed to the third argument of > map_user_kiobuf? > > can I do something like > > addr = vmalloc (size); > ... > map_user_kiobuf (xxx, iobuf, (unsigned long) addr, xxx); > [ ... mess around with iobuf'd pages ... ] > unmap_kiobuf (iobuf);
An address from the user space. For example the 2nd argument of a read() [both the user space system call and a character device read]. Not sure about the vmalloc() aspect.
Just to save you a little time, you may be needing the recently added page_address() macro as well to get a 32 bit address back out of a page object suitable for a DMA chip.
Doug Gilbert
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