mm: enhance free_reserved_area() to support poisoning memory with zero

Address more review comments from last round of code review.
1) Enhance free_reserved_area() to support poisoning freed memory with
   pattern '0'. This could be used to get rid of poison_init_mem()
   on ARM64.
2) A previous patch has disabled memory poison for initmem on s390
   by mistake, so restore to the original behavior.
3) Remove redundant PAGE_ALIGN() when calling free_reserved_area().

Signed-off-by: Jiang Liu <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: David Howells <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jeremy Fitzhardinge <[email protected]>
Cc: Jianguo Wu <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Kamezawa Hiroyuki <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Michel Lespinasse <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Rusty Russell <[email protected]>
Cc: Tang Chen <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Wen Congyang <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Cc: Yinghai Lu <[email protected]>
Cc: Russell King <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c
index d54848d4e464..218c29c14bb3 100644
--- a/arch/alpha/mm/init.c
+++ b/arch/alpha/mm/init.c
@@ -319,13 +319,13 @@ mem_init(void)
 void
 free_initmem(void)
 {
-	free_initmem_default(0);
+	free_initmem_default(-1);
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD
 void
 free_initrd_mem(unsigned long start, unsigned long end)
 {
-	free_reserved_area((void *)start, (void *)end, 0, "initrd");
+	free_reserved_area((void *)start, (void *)end, -1, "initrd");
 }
 #endif