On Thu, Jan 21, 2016 at 8:15 AM, Vasant Hegde
[off-list ref] wrote:

With commit 90a545e9 (restrict /dev/mem to idle io memory ranges) mapping
rtas_rmo_buf from user space is failing. Hence we are not able to make
RTAS syscall.

This patch calls page_is_rtas_user_buf before calling iomem_is_exclusive
in  devmem_is_allowed(). This will allow user space to map rtas_rmo_buf
and we are able to make RTAS syscall.

Reported-by: Bharata B Rao <redacted>
CC: Dan Williams <redacted>

Acked-by: Dan Williams <redacted>