page_alloc: Introduce get_order()

Compute the power of 2 order of a size. Use it in
page_memalign. Other users are looming.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Andrew Jones <drjones@redhat.com>

2 files changed, 7 insertions, 1 deletions

diff --git a/lib/alloc_page.c b/lib/alloc_page.c
index ed23638..7c8461a 100644
--- a/lib/alloc_page.c
+++ b/lib/alloc_page.c
@@ -155,7 +155,7 @@ static void *page_memalign(size_t alignment, size_t size)
 	if (!size)
 		return NULL;
 
-	order = is_power_of_2(n) ? fls(n) : fls(n) + 1;
+	order = get_order(n);
 
 	return alloc_pages(order);
 }
@@ -175,3 +175,8 @@ void page_alloc_ops_enable(void)
 {
 	alloc_ops = &page_alloc_ops;
 }
+
+int get_order(size_t size)
+{
+	return is_power_of_2(size) ? fls(size) : fls(size) + 1;
+}
diff --git a/lib/alloc_page.h b/lib/alloc_page.h
index 739a91d..e6a51d2 100644
--- a/lib/alloc_page.h
+++ b/lib/alloc_page.h
@@ -15,5 +15,6 @@ void *alloc_pages(unsigned long order);
 void free_page(void *page);
 void free_pages(void *mem, unsigned long size);
 void free_pages_by_order(void *mem, unsigned long order);
+int get_order(size_t size);
 
 #endif