a bit more but unfinished

2 files changed, 158 insertions, 0 deletions

diff --git a/vm/vm_anon.c b/vm/vm_anon.c
new file mode 100644
index 00000000..fac7528c
--- /dev/null
+++ b/vm/vm_anon.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2013 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <kern/kmem.h>
+#include <kern/init.h>
+#include <kern/list.h>
+#include <kern/llsync.h>
+#include <kern/macros.h>
+#include <kern/mutex.h>
+#include <kern/panic.h>
+#include <kern/stddef.h>
+#include <kern/stdint.h>
+#include <vm/vm_anon.h>
+#include <vm/vm_object.h>
+
+/*
+ * Anonymous memory container.
+ */
+struct vm_anon {
+    struct vm_object object;
+    unsigned long nr_refs;
+    size_t size;
+};
+
+/*
+ * Anonymous pager operations.
+ */
+static void vm_anon_ref(struct vm_object *object);
+static void vm_anon_unref(struct vm_object *object);
+static int vm_anon_get(struct vm_object *object, uint64_t offset,
+                       struct list *pages, int access_prot, int advice);
+
+static struct vm_object_pager vm_anon_pager = {
+    .ref = vm_anon_ref,
+    .unref = vm_anon_unref,
+    .get = vm_anon_get,
+};
+
+static struct kmem_cache vm_anon_cache;
+
+void __init
+vm_anon_setup(void)
+{
+    kmem_cache_init(&vm_anon_cache, "vm_anon", sizeof(struct vm_anon), 0,
+                    NULL, NULL, NULL, 0);
+}
+
+struct vm_object *
+vm_anon_create(size_t size)
+{
+    struct vm_anon *anon;
+
+    anon = kmem_cache_alloc(&vm_anon_cache);
+
+    if (anon == NULL)
+        return NULL;
+
+    vm_object_init(&anon->object, &vm_anon_pager);
+    anon->nr_refs = 1;
+    anon->size = size;
+    return &anon->object;
+}
+
+static void
+vm_anon_ref(struct vm_object *object)
+{
+    struct vm_anon *anon;
+
+    anon = structof(object, struct vm_anon, object);
+
+    /* TODO Use atomic operations */
+    mutex_lock(&anon->object.lock);
+    anon->nr_refs++;
+    mutex_unlock(&anon->object.lock);
+}
+
+static void
+vm_anon_unref(struct vm_object *object)
+{
+    struct vm_anon *anon;
+    unsigned int nr_refs;
+
+    anon = structof(object, struct vm_anon, object);
+
+    mutex_lock(&anon->object.lock);
+    anon->nr_refs--;
+    nr_refs = anon->nr_refs;
+    mutex_unlock(&anon->object.lock);
+
+    if (nr_refs == 0)
+        panic("vm_anon: destruction not implemented");
+}
+
+static int
+vm_anon_get(struct vm_object *object, uint64_t offset, struct list *pages,
+            int access_prot, int advice)
+{
+    (void)object;
+    (void)offset;
+    (void)pages;
+    (void)access_prot;
+    (void)advice;
+
+    return -1;
+}
diff --git a/vm/vm_anon.h b/vm/vm_anon.h
new file mode 100644
index 00000000..f3839233
--- /dev/null
+++ b/vm/vm_anon.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2013 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * Anonymous memory.
+ *
+ * Historically, this memory type refers to memory that isn't backed by a file
+ * on Unix, and as a result has no name.
+ */
+
+#ifndef _VM_VM_ANON_H
+#define _VM_VM_ANON_H
+
+#include <kern/stddef.h>
+#include <vm/vm_object.h>
+
+/*
+ * Initialize the vm_anon module.
+ */
+void vm_anon_setup(void);
+
+/*
+ * Create an anonymous memory object.
+ */
+struct vm_object * vm_anon_create(size_t size);
+#endif /* _VM_VM_ANON_H */