Add pager interface ; implement basic functionnality to replace private maps.

1 files changed, 73 insertions, 0 deletions

diff --git a/src/kernel/include/pager.h b/src/kernel/include/pager.h
new file mode 100644
index 0000000..5491d10
--- /dev/null
+++ b/src/kernel/include/pager.h
@@ -0,0 +1,73 @@
+#pragma once
+
+#include <hashtbl.h>
+#include <mutex.h>
+
+#include <paging.h>
+
+#define PAGE_PINNED		0x01
+#define PAGE_ACCESSED	0x02
+#define PAGE_DIRTY		0x04
+
+typedef struct pager pager_t;
+typedef struct user_region user_region_t;
+typedef struct fs_node fs_node_t;
+
+typedef struct {
+	size_t (*read)(fs_node_t* data, size_t offset, size_t len, char* ptr);
+	size_t (*write)(fs_node_t* data, size_t offset, size_t len, const char* ptr);
+	bool (*resize)(fs_node_t* data, size_t new_size);
+} vfs_pager_ops_t;
+
+typedef struct {
+	void (*page_in)(pager_t *p, size_t offset, size_t len);			// allocates the pages
+	void (*page_commit)(pager_t *p, size_t offset, size_t len);		// writes pages back to storage (if applicable)
+	void (*page_out)(pager_t *p, size_t offset, size_t len);		// frees the pages (no need to write back)
+	void (*page_release)(pager_t *p, size_t offset, size_t len);	// called on delete/resize
+} pager_ops_t;
+
+typedef struct pager {
+	pager_ops_t *ops;
+
+	union {
+		struct {
+			fs_node_t* vfs_data;
+			vfs_pager_ops_t *vfs_ops;
+		} vfs_pager;
+		struct {
+			size_t phys_offset;
+		} device_pager;
+	};
+
+	size_t size;
+
+	hashtbl_t *pages;
+	mutex_t lock;
+
+	user_region_t *maps;
+} pager_t;
+
+pager_t* new_swap_pager(size_t size);
+pager_t* new_vfs_pager(size_t size, fs_node_t* vfs_node, vfs_pager_ops_t *vfs_ops);
+pager_t* new_dev_pager(size_t size, size_t phys_offset);
+
+void delete_pager(pager_t *p);
+
+bool pager_resize(pager_t *p, size_t newsize);
+
+// void pager_pin_region(pager_t *pager, size_t offset, size_t len);	// implement later
+// void pager_unpin_region(pager_t *pager, size_t offset, size_t len);
+
+void pager_access(pager_t *p, size_t offset, size_t len, bool accessed, bool dirty);
+void pager_commit_dirty(pager_t *p);
+
+int pager_get_frame(pager_t *p, size_t offset);
+
+size_t pager_read(pager_t *p, size_t offset, size_t len, char* buf);
+size_t pager_write(pager_t *p, size_t offset, size_t len, const char* buf);
+
+void pager_add_map(pager_t *p, user_region_t *reg);
+void pager_rm_map(pager_t *p, user_region_t *reg);
+
+
+/* vim: set ts=4 sw=4 tw=0 noet :*/