Merge 5.13-rc2 into staging-next

We need the staging and iio fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 10 insertions, 1 deletions

diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index 33832e36bdb7..e2ed355438c9 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -157,7 +157,16 @@ void __init setup_arch_memory(void)
 	min_high_pfn = PFN_DOWN(high_mem_start);
 	max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
 
-	max_zone_pfn[ZONE_HIGHMEM] = min_low_pfn;
+	/*
+	 * max_high_pfn should be ok here for both HIGHMEM and HIGHMEM+PAE.
+	 * For HIGHMEM without PAE max_high_pfn should be less than
+	 * min_low_pfn to guarantee that these two regions don't overlap.
+	 * For PAE case highmem is greater than lowmem, so it is natural
+	 * to use max_high_pfn.
+	 *
+	 * In both cases, holes should be handled by pfn_valid().
+	 */
+	max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn;
 
 	high_memory = (void *)(min_high_pfn << PAGE_SHIFT);