[PATCH v2] mm/mm_init.c: Extend init unavailable range doc info

[Serge Semin <fancer.lancer@gmail.com>]

Besides of the already described reasons the pages backended memory holes
might present due to having non-memory regions covered by the contiguous
flatmem mapping. Add such note to the init_unavailable_range() method kdoc
in order to point out to one more reason of having the function executed
for such regions.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>

---

Link: https://lore.kernel.org/linux-mips/20231122182419.30633-6-fancer.lancer@gmail.com/
Changelog v2:
- The holes in the memory are actually justified by having the flatmem
  mapping model. Change the patch and the log accordingly. (@Mike)
---
 mm/mm_init.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 077bfe393b5e..824bf53e8253 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -796,6 +796,7 @@ overlap_memmap_init(unsigned long zone, unsigned long *pfn)
  * - physical memory bank size is not necessarily the exact multiple of the
  *   arbitrary section size
  * - early reserved memory may not be listed in memblock.memory
+ * - non-memory regions covered by the contigious flatmem mapping
  * - memory layouts defined with memmap= kernel parameter may not align
  *   nicely with memmap sections
  *
-- 
2.42.1