1 files changed, 113 insertions, 0 deletions
diff --git a/src/kernel/mem/seg.cpp b/src/kernel/mem/seg.cpp
new file mode 100644
index 0000000..c29e94e
--- /dev/null
+++ b/src/kernel/mem/seg.cpp
@@ -0,0 +1,113 @@
+#include "seg.h"
+#include "mem.h"
+#include <core/sys.h>
+
+/*	Call this function when mapping a segment to a page directory.
+	Calls the appropriate map method and updates the segment's and pagedir's information. */
+segment_map *seg_map(segment* seg, page_directory *pagedir, size_t offset) {
+	segment_map *sm = seg->map(seg, pagedir, offset);
+	if (sm == 0) return 0;
+	seg->mappings++;
+	sm->seg = seg;
+	sm->pagedir = pagedir;
+	sm->next = pagedir->mappedSegs;
+	pagedir->mappedSegs = sm;
+	return sm;
+}
+
+/*	Call this function when unmapping a segment from a page directory.
+	The segment will automatically be deleted if it is not mapped.
+	Calls the appropriate unmap method and updates the segment's and pagedir's information. */
+void seg_unmap(segment_map *map) {
+	map->seg->unmap(map);
+	if (map->pagedir->mappedSegs == map) {
+		map->pagedir->mappedSegs = map->pagedir->mappedSegs->next;
+	} else {
+		segment_map *m = map->pagedir->mappedSegs;
+		while (m->next != 0 && m->next != map) m = m->next;
+		if (m->next == map) m->next = map->next;
+	}
+	map->seg->mappings--;
+	if (map->seg->mappings == 0) {
+		map->seg->del(map->seg);
+		kfree(map->seg->seg_data);
+		kfree(map->seg);
+	}
+	kfree (map);
+}
+
+// ************************************   SIMPLESEG stuff *************
+ 
+static segment_map* simpleseg_map(segment* seg, page_directory* pagedir, size_t offset);
+static void simpleseg_unmap(segment_map*);
+static void simpleseg_delete(segment *seg);
+static int simpleseg_handleFault(segment_map* map, size_t addr, int write);
+
+/*	Call this when creating a simpleseg.
+	Creates the simpleseg structure and the segment structure and fills them up. */
+segment* simpleseg_make(size_t start, size_t len, int writable) {
+	simpleseg *ss = new simpleseg(); 
+	segment *se = new segment();
+	se->seg_data = ss;
+	se->mappings = 0;
+	se->map = simpleseg_map;
+	se->unmap = simpleseg_unmap;
+	se->del = simpleseg_delete;
+	se->handle_fault = simpleseg_handleFault;
+	ss->writable = writable; ss->start = start; ss->len = len;
+	return se;
+}
+
+/*	For internal use only. Called when a simpleseg is mapped to a pagedirectory. */
+segment_map* simpleseg_map(segment* seg, page_directory* pagedir, size_t offset) {
+	segment_map *sm = new segment_map();
+	sm->start = ((simpleseg*)(seg->seg_data))->start;
+	sm->len = ((simpleseg*)(seg->seg_data))->len;
+	return sm;
+}
+
+/*	For internal use only. Called when a simpleseg is unmapped.
+	Frees all the allocated pages. */
+void simpleseg_unmap(segment_map* sm) {
+	size_t i;
+	for (i = sm->start; i < sm->start + sm->len; i += 0x1000) {
+		page_unmapFree(pagedir_getPage(sm->pagedir, i, 0));
+	}
+}
+
+/*	For internal use only. Handles a page fault. Can allocate and map a frame if necessary. */
+int simpleseg_handleFault(segment_map* sm, size_t addr, int write) {
+	simpleseg *ss = (simpleseg*)sm->seg->seg_data;
+	if (write && !ss->writable) return 1;
+	addr &= 0xFFFFF000;
+	page *p = pagedir_getPage(sm->pagedir, addr, 1);
+	if (p->frame != 0) return 1;
+	page_map(p, frame_alloc(), 1, ss->writable);
+	return 0;
+}
+
+/*	For internal use only. Called when the simpleseg is deleted. Does nothing. */
+void simpleseg_delete(segment* seg) {
+}
+
+/*	Call this to resize a simpleseg. Ajusts the size and frees pages if the new size is smaller.*/
+int simpleseg_resize(segment_map *map, size_t len) {
+	size_t i;
+
+	if (map == 0) return -1;
+	if (map->seg->del != simpleseg_delete) return -2;	//check segment is a simpleseg
+
+	simpleseg *s = (simpleseg*)map->seg->seg_data;
+	if (len & 0xFFF) len = (len & 0xFFFFF000) + 0x1000;
+	if (len < map->len) {
+		for (i = map->start + len; i < map->start + map->len; i += 0x1000) {
+			page_unmapFree(pagedir_getPage(map->pagedir, i, 0));
+		}
+		map->len = len;
+		s->len = len;
+	} else if (len > map->len) {
+		map->len = len;
+		s->len = len;
+	}
+	return 0;
+}