Messages in this thread | | | From | Michal Sojka <> | Subject | Re: [PATCH 1/3] uio: Allow handling of non page-aligned memory regions | Date | Thu, 16 Mar 2017 14:33:25 +0100 |
| |
On Thu, Mar 16 2017, Greg KH wrote: > On Thu, Mar 16, 2017 at 01:45:50PM +0100, Michal Sojka wrote: >> On Thu, Mar 16 2017, Greg KH wrote: >> > On Tue, Mar 07, 2017 at 03:09:46PM +0100, Michal Sojka wrote: >> >> Since commit b65502879556 ("uio: we cannot mmap unaligned page >> >> contents") addresses and sizes of UIO memory regions must be >> >> page-aligned. If the address in the BAR register is not page-aligned, >> >> the mentioned commit forces the UIO driver to round the address down >> >> to the page size. Then, there is no easy way for user-space to learn >> >> the offset of the actual memory region within the page, because the >> >> offset seen in the sysfs is calculated from the rounded address and >> >> thus it is always zero. >> >> >> >> Fix that problem by including the offset in struct uio_mem. UIO >> >> drivers can set this field and its value is reported via sysfs. >> > >> > It is, where? >> >> /sys/class/uio/uio0/maps/map0/offset > > Did you change the Documentation/ABI entry for it?
No, because it seems that UIO is not documented there.
-Michal
| |