[RFC v3] arm:extend the reserved mrmory for initrd to be page aligned

[Wang, Yalin]

this patch extend the start and end address of initrd to be page aligned,
so that we can free all memory including the un-page aligned head or tail
page of initrd, if the start or end address of initrd are not page
aligned, the page can't be freed by free_initrd_mem() function.

Signed-off-by: Yalin Wang <yalin.wang at sonymobile.com>
---
 arch/arm/mm/init.c   | 5 +++++
 arch/arm64/mm/init.c | 8 +++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 659c75d..9221645 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -636,6 +636,11 @@ static int keep_initrd;
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
 	if (!keep_initrd) {
+		if (start == initrd_start)
+			start = round_down(start, PAGE_SIZE);
+		if (end == initrd_end)
+			end = round_up(end, PAGE_SIZE);
+
 		poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
 		free_reserved_area((void *)start, (void *)end, -1, "initrd");
 	}
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 5472c24..c5512f6 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -334,8 +334,14 @@ static int keep_initrd;
 
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
-	if (!keep_initrd)
+	if (!keep_initrd) {
+		if (start == initrd_start)
+			start = round_down(start, PAGE_SIZE);
+		if (end == initrd_end)
+			end = round_up(end, PAGE_SIZE);
+
 		free_reserved_area((void *)start, (void *)end, 0, "initrd");
+	}
 }
 
 static int __init keepinitrd_setup(char *__unused)
-- 
2.1.0