1 files changed, 56 insertions, 0 deletions
diff --git a/src/kernel/ipc/shm.c b/src/kernel/ipc/shm.c
new file mode 100644
index 0000000..0a0d3ee
--- /dev/null
+++ b/src/kernel/ipc/shm.c
@@ -0,0 +1,56 @@
+#include "shm.h"
+#include <mem/mem.h>
+#include <mem/seg.h>
+
+struct segment* shmseg_make(size_t len, struct process* owner) {
+	struct shmseg *ss = kmalloc(sizeof(struct shmseg));
+	struct segment *se = kmalloc(sizeof(struct segment));
+	unsigned i;
+	se->seg_data = ss;
+	se->mappings = 0;
+	se->map = shmseg_map;
+	se->unmap = shmseg_unmap;
+	se->delete = shmseg_delete;
+	se->handle_fault = shmseg_handleFault;
+	ss->len = len;
+	ss->owner = owner;
+	ss->frames = kmalloc((len / 0x1000) * sizeof(uint32_t));
+	for (i = 0; i < (len / 0x1000); i++) ss->frames[i] = 0;
+	return se;
+}
+
+struct segment_map *shmseg_map(struct segment *seg, struct page_directory *pagedir, size_t offset) {
+	struct segment_map *sm = kmalloc(sizeof(struct segment_map));
+	sm->start = offset;
+	sm->len = ((struct shmseg*)(seg->seg_data))->len;
+	return sm;
+}
+
+void shmseg_unmap(struct segment_map *sm) {
+	size_t i;
+	for (i = sm->start; i < sm->start + sm->len; i += 0x1000) {
+		page_unmap(pagedir_getPage(sm->pagedir, i, 0));
+	}
+}
+
+int shmseg_handleFault(struct segment_map *sm, size_t addr, int write) {
+	struct shmseg *ss = sm->seg->seg_data;
+	addr &= 0xFFFFF000;
+	struct page *p = pagedir_getPage(sm->pagedir, addr, 1);
+	if (p->frame != 0) return 1;
+	int frame_idx = (addr - sm->start) / 0x1000;
+	if (ss->frames[frame_idx] == 0) {
+		ss->frames[frame_idx] = frame_alloc();
+	}
+	page_map(p, ss->frames[frame_idx], 1, 1);
+	return 0;
+}
+
+void shmseg_delete(struct segment *seg) {
+	struct shmseg *ss = seg->seg_data;
+	unsigned i;
+	for (i = 0; i < (ss->len / 0x1000); i++) {
+		if (ss->frames[i] != 0) frame_free(ss->frames[i]);
+	}
+	kfree(ss->frames);
+}