From 149b197a652f36ee77bfa8c902b9f83dbfc304fb Mon Sep 17 00:00:00 2001
From: Mathieu Maret <mathieu.maret@gmail.com>
Date: Fri, 9 Nov 2018 17:07:39 +0100
Subject: [PATCH] mem: implement ref to physical page

---
 core/mem.c   | 19 +++++++++++++++++--
 core/mem.h   |  5 +++--
 tests/test.c |  8 ++++----
 3 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/core/mem.c b/core/mem.c
index 19bea4a..8e1bdc7 100644
--- a/core/mem.c
+++ b/core/mem.c
@@ -43,7 +43,7 @@ struct mem_desc *addr2memDesc(unsigned long addr)
 	return page_desc + idx;
 }
 
-unsigned long allocPage(void)
+unsigned long allocPhyPage(void)
 {
 	if (list_is_empty(free_page)) {
 		return (unsigned long)NULL;
@@ -54,7 +54,7 @@ unsigned long allocPage(void)
 	return mem->phy_addr;
 }
 
-int unrefPage(unsigned long addr)
+int unrefPhyPage(unsigned long addr)
 {
 	struct mem_desc *mem = addr2memDesc(addr);
 	if (!mem) {
@@ -68,3 +68,18 @@ int unrefPage(unsigned long addr)
 
 	return 0;
 }
+
+int refPhyPage(unsigned long addr)
+{
+	struct mem_desc *mem = addr2memDesc(addr);
+	if (!mem) {
+		return -1;
+	}
+	mem->ref++;
+	if (mem->ref == 1) {
+		list_add_tail(used_page, mem);
+		list_delete(free_page, mem);
+	}
+
+	return 0;
+}
diff --git a/core/mem.h b/core/mem.h
index 084c214..1249c0d 100644
--- a/core/mem.h
+++ b/core/mem.h
@@ -17,5 +17,6 @@ struct mem_desc{
 
 
 int memSetup(unsigned long upper_mem);
-unsigned long allocPage(void);
-int unrefPage(unsigned long addr);
+unsigned long allocPhyPage(void);
+int unrefPhyPage(unsigned long addr);
+int refPhyPage(unsigned long addr);
diff --git a/tests/test.c b/tests/test.c
index c1271bf..a92b09e 100644
--- a/tests/test.c
+++ b/tests/test.c
@@ -13,7 +13,7 @@ static void testPhymem()
 	int allocCount = 0;
 	int freeCount  = 0;
 
-	while ((page = (struct mem_desc *)allocPage()) != NULL) {
+	while ((page = (struct mem_desc *)allocPhyPage()) != NULL) {
 		page->phy_addr = allocCount;
 		allocCount++;
 		list_add_tail(allocated_page_list, page);
@@ -24,17 +24,17 @@ static void testPhymem()
 		if (page->phy_addr != (ulong)freeCount) {
 			printf("Error page %d modified\n", (ulong)page);
 		}
-		if (unrefPage((ulong)page)) {
+		if (unrefPhyPage((ulong)page)) {
 			printf("Failed to free page %d\n", (ulong)page);
 		}
 		freeCount++;
 	}
 	printf("%d pages freed\n", freeCount);
 
-	if ((page = (struct mem_desc *)allocPage()) == NULL) {
+	if ((page = (struct mem_desc *)allocPhyPage()) == NULL) {
 		printf("Error ! Cannot allocate memory\n");
 	} else {
-		unrefPage((ulong)page);
+		unrefPhyPage((ulong)page);
 	}
 }