[PATCH v2 1/4] mm/page_reporting: add PAGE_REPORTING_ORDER_UNSPECIFIED

[Yuvraj Sakshith <yuvraj.sakshith@oss.qualcomm.com>]

Drivers can pass order of pages to be reported while
registering itself. Today, this is a magic number, 0.

Label this with PAGE_REPORTING_ORDER_UNSPECIFIED and
check for it when the driver is being registered.

This macro will be used in relevant drivers next.

Signed-off-by: Yuvraj Sakshith <yuvraj.sakshith@oss.qualcomm.com>
---
 include/linux/page_reporting.h |  1 +
 mm/page_reporting.c            | 14 +++++---------
 2 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/include/linux/page_reporting.h b/include/linux/page_reporting.h
index fe648dfa3..d1886c657 100644
--- a/include/linux/page_reporting.h
+++ b/include/linux/page_reporting.h
@@ -7,6 +7,7 @@
 
 /* This value should always be a power of 2, see page_reporting_cycle() */
 #define PAGE_REPORTING_CAPACITY		32
+#define PAGE_REPORTING_ORDER_UNSPECIFIED	0
 
 struct page_reporting_dev_info {
 	/* function that alters pages to make them "reported" */
diff --git a/mm/page_reporting.c b/mm/page_reporting.c
index e4c428e61..51cd88faf 100644
--- a/mm/page_reporting.c
+++ b/mm/page_reporting.c
@@ -12,7 +12,7 @@
 #include "internal.h"
 
 /* Initialize to an unsupported value */
-unsigned int page_reporting_order = -1;
+unsigned int page_reporting_order = PAGE_REPORTING_ORDER_UNSPECIFIED;
 
 static int page_order_update_notify(const char *val, const struct kernel_param *kp)
 {
@@ -25,12 +25,7 @@ static int page_order_update_notify(const char *val, const struct kernel_param *
 
 static const struct kernel_param_ops page_reporting_param_ops = {
 	.set = &page_order_update_notify,
-	/*
-	 * For the get op, use param_get_int instead of param_get_uint.
-	 * This is to make sure that when unset the initialized value of
-	 * -1 is shown correctly
-	 */
-	.get = &param_get_int,
+	.get = &param_get_uint,
 };
 
 module_param_cb(page_reporting_order, &page_reporting_param_ops,
@@ -369,8 +364,9 @@ int page_reporting_register(struct page_reporting_dev_info *prdev)
 	 * pageblock_order.
 	 */
 
-	if (page_reporting_order == -1) {
-		if (prdev->order > 0 && prdev->order <= MAX_PAGE_ORDER)
+	if (page_reporting_order == PAGE_REPORTING_ORDER_UNSPECIFIED) {
+		if (prdev->order != PAGE_REPORTING_ORDER_UNSPECIFIED &&
+			prdev->order <= MAX_PAGE_ORDER)
 			page_reporting_order = prdev->order;
 		else
 			page_reporting_order = pageblock_order;
-- 
2.34.1