powerpc: Don't use a 16G page if beyond mem= limits

If mem= is used on the boot command line to limit memory then the memory block where a 16G page resides may not be available.

Thanks to Michael Ellerman for finding the problem.

---

arch/powerpc/mm/hash_utils_64.c | 6 ++++--

1 file changed, 4 insertions(+), 2 deletions(-)

index 5c64af1..8d5b475 100644
@@ -382,8 +382,10 @@ static int __init htab_dt_scan_hugepage_blocks(unsigned long node,

	printk(KERN_INFO "Huge page(16GB) memory: "
			"addr = 0x%lX size = 0x%lX pages = %d\n",
			phys_addr, block_size, expected_pages);

- lmb_reserve(phys_addr, block_size * expected_pages);
- add_gpage(phys_addr, block_size, expected_pages);
+ if (phys_addr + (16 * GB) <= lmb_end_of_DRAM()) {
+ lmb_reserve(phys_addr, block_size * expected_pages);
+ add_gpage(phys_addr, block_size, expected_pages);
+ }

	return 0;
}

#endif /* CONFIG_HUGETLB_PAGE */