In the near future, we are considering to use a common xen/domain heap for
Arm 32-bit V8-R. In this setup, both PADDR_BITS and BITS_PER_LONG will be
32. Therefore, the condition PADDR_BITS >= BITS_PER_LONG will become true.
Looking at the commit that introduce the BUILD_BUG_ON (88e3ed6164
"x86/NUMA: make init_node_heap() respect Xen heap limit") and the current
use, it seems this check was mainly to ensure that the shift of xenheap_bits
is not going to be undefined (>> N for a N-bit type is undefined).
So far, all the shifts are using "xenheap_bits - PAGE_SHIFT". Therefore, the
existing code should work for 32-bit architecture as long as the result of
the substraction is below 32.
Therefore relax the BUILD_BUG_ON() to check that (PADDR_BITS - PAGE_SHIFT)
is not equal of above BITS_PER_LONG.
Note that we would need further precaution if we ended up to use
'xenheap_bits' alone in shifts.
Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com>
Signed-off-by: Julien Grall <julien@xen.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
