implement sys_munmap()

kernel/include/page.h

@@ -1,7 +1,21 @@
 #ifndef __HEADER_PAGE_H
 #define __HEADER_PAGE_H
 
+struct page {
+	struct list_head list;
+	uint64_t flags;
+	int64_t count;
+};
+
+/* flags */
+#define	PAGE_IN_LIST	0x0001UL
+
+struct page *phys_to_page(uintptr_t phys);
+uintptr_t page_to_phys(struct page *page);
+
 void *allocate_pages(int npages, enum ihk_mc_ap_flag flag);
 void free_pages(void *va, int npages);
+void begin_free_pages_pending(void);
+void finish_free_pages_pending(void);
 
 #endif