This patch apply against a clean 2.2.9 kernel. It can be found
at the url http://www.ie2.u-psud.fr/~arnal/linux/index.html.
The main goal is to change the rtc driver so many process can
access the interrupt counter at the same time. To obtain this,
process can read the value of the counter via a new entry in
the proc filesystem "/proc/rtcitr".
Other change make by this patch is the modularization of the driver.
I have some question about the mapping of memory in the kernel. At this
time, operation support by the "/proc/rtcitr" is only read and select.
I would like to add mapping, but have no success with it. I try to
vmalloc a buffer in the driver, and then to call remap_page_range
to mmap this buffer into user space. When I call mmap from the user
process, it go in the get_rtc_intr_mmap function, calling the remap
function with no error, but after this, try to display the buffer
in user process give nothing. I can't find any documentation about
mapping anywhere, so can anyone tell me what's wrong with this code.
Laurent.
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