[PATCH 5.17 328/343] Revert "powerpc: Set max_mapnr correctly"

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>

commit 1ff5c8e8c835e8a81c0868e3050c76563dd56a2c upstream.

This reverts commit 602946ec2f90d5bd965857753880db29d2d9a1e9.

If CONFIG_HIGHMEM is enabled, no highmem will be added with max_mapnr
set to max_low_pfn, see mem_init():

  for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
        ...
        free_highmem_page();
  }

Now that virt_addr_valid() has been fixed in the previous commit, we can
revert the change to max_mapnr.

Fixes: 602946ec2f90 ("powerpc: Set max_mapnr correctly")
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Reported-by: Erhard F. <erhard_f@xxxxxxxxxxx>
[mpe: Update change log to reflect series reordering]
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220406145802.538416-2-mpe@xxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/powerpc/mm/mem.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -255,7 +255,7 @@ void __init mem_init(void)
 #endif
 
 	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
-	set_max_mapnr(max_low_pfn);
+	set_max_mapnr(max_pfn);
 
 	kasan_late_init();