Initial Spring 2016 commit.

kern/vm/addrspace.c

@@ -0,0 +1,182 @@
+/*
+ * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
+ *	The President and Fellows of Harvard College.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <types.h>
+#include <kern/errno.h>
+#include <lib.h>
+#include <addrspace.h>
+#include <vm.h>
+#include <proc.h>
+
+/*
+ * Note! If OPT_DUMBVM is set, as is the case until you start the VM
+ * assignment, this file is not compiled or linked or in any way
+ * used. The cheesy hack versions in dumbvm.c are used instead.
+ */
+
+struct addrspace *
+as_create(void)
+{
+	struct addrspace *as;
+
+	as = kmalloc(sizeof(struct addrspace));
+	if (as == NULL) {
+		return NULL;
+	}
+
+	/*
+	 * Initialize as needed.
+	 */
+
+	return as;
+}
+
+int
+as_copy(struct addrspace *old, struct addrspace **ret)
+{
+	struct addrspace *newas;
+
+	newas = as_create();
+	if (newas==NULL) {
+		return ENOMEM;
+	}
+
+	/*
+	 * Write this.
+	 */
+
+	(void)old;
+
+	*ret = newas;
+	return 0;
+}
+
+void
+as_destroy(struct addrspace *as)
+{
+	/*
+	 * Clean up as needed.
+	 */
+
+	kfree(as);
+}
+
+void
+as_activate(void)
+{
+	struct addrspace *as;
+
+	as = proc_getas();
+	if (as == NULL) {
+		/*
+		 * Kernel thread without an address space; leave the
+		 * prior address space in place.
+		 */
+		return;
+	}
+
+	/*
+	 * Write this.
+	 */
+}
+
+void
+as_deactivate(void)
+{
+	/*
+	 * Write this. For many designs it won't need to actually do
+	 * anything. See proc.c for an explanation of why it (might)
+	 * be needed.
+	 */
+}
+
+/*
+ * Set up a segment at virtual address VADDR of size MEMSIZE. The
+ * segment in memory extends from VADDR up to (but not including)
+ * VADDR+MEMSIZE.
+ *
+ * The READABLE, WRITEABLE, and EXECUTABLE flags are set if read,
+ * write, or execute permission should be set on the segment. At the
+ * moment, these are ignored. When you write the VM system, you may
+ * want to implement them.
+ */
+int
+as_define_region(struct addrspace *as, vaddr_t vaddr, size_t memsize,
+		 int readable, int writeable, int executable)
+{
+	/*
+	 * Write this.
+	 */
+
+	(void)as;
+	(void)vaddr;
+	(void)memsize;
+	(void)readable;
+	(void)writeable;
+	(void)executable;
+	return ENOSYS;
+}
+
+int
+as_prepare_load(struct addrspace *as)
+{
+	/*
+	 * Write this.
+	 */
+
+	(void)as;
+	return 0;
+}
+
+int
+as_complete_load(struct addrspace *as)
+{
+	/*
+	 * Write this.
+	 */
+
+	(void)as;
+	return 0;
+}
+
+int
+as_define_stack(struct addrspace *as, vaddr_t *stackptr)
+{
+	/*
+	 * Write this.
+	 */
+
+	(void)as;
+
+	/* Initial user-level stack pointer */
+	*stackptr = USERSTACK;
+
+	return 0;
+}
+