Revised task initialisation, revising mmap yet.

tasks/mm0/src/dev.c

@@ -0,0 +1,45 @@
+/*
+ * This is yet unused, it is more of an anticipation
+ * of how mmaped devices would be mapped with a pager.
+ */
+
+struct mmap_device {
+	struct list_head page_list;	/* Dyn-allocated page list */
+	unsigned long pfn_start;	/* Physical pfn start */
+	unsigned long pfn_end;		/* Physical pfn end */
+};
+
+struct page *mmap_device_page_in(struct vm_object *vm_obj,
+				 unsigned long pfn_offset)
+{
+	struct vm_file *f = vm_obj_to_file(vm_obj);
+	struct mmap_device *mmdev = f->private_data;
+	struct page *page;
+
+	/* Check if its within device boundary */
+	if (pfn_offset >= mmdev->pfn_end - mmdev->pfn_start)
+		return -1;
+
+	/* Simply return the page if found */
+	list_for_each_entry(page, &mmdev->page_list, list)
+		if (page->offset == pfn_offset)
+			return page;
+
+	/* Otherwise allocate one of our own for that offset and return it */
+	page = kzalloc(sizeof(struct page));
+	INIT_LIST_HEAD(&page->list);
+	spin_lock_init(&page->lock);
+	page->offset = pfn_offset;
+	page->owner = vm_obj;
+	page->flags = DEVICE_PAGE;
+	list_add(&page->list, &mmdev->page_list)
+
+	return page;
+}
+
+/* All mmapable devices are handled by this */
+struct vm_pager mmap_device_pager {
+	.page_in = mmap_device_page_in,
+};
+
+