Import of uvm from NetBSD. Some local changes, some code disabled

1 files changed, 163 insertions, 0 deletions

diff --git a/sys/uvm/uvm_io.c b/sys/uvm/uvm_io.c
new file mode 100644
index 00000000000..603e04b26d9
--- /dev/null
+++ b/sys/uvm/uvm_io.c
@@ -0,0 +1,163 @@
+/*	$NetBSD: uvm_io.c,v 1.7 1998/10/11 23:18:20 chuck Exp $	*/
+
+/*
+ * XXXCDC: "ROUGH DRAFT" QUALITY UVM PRE-RELEASE FILE!   
+ *	   >>>USE AT YOUR OWN RISK, WORK IS NOT FINISHED<<<
+ */
+/*
+ *
+ * Copyright (c) 1997 Charles D. Cranor and Washington University.
+ * All rights reserved.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed by Charles D. Cranor and
+ *      Washington University.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+ *
+ * from: Id: uvm_io.c,v 1.1.2.2 1997/12/30 12:02:00 mrg Exp
+ */
+
+/*
+ * uvm_io.c: uvm i/o ops
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/mman.h>
+#include <sys/proc.h>
+#include <sys/malloc.h>
+#include <sys/uio.h>
+
+#include <vm/vm.h>
+#include <vm/vm_page.h>
+#include <vm/vm_kern.h>
+
+#include <uvm/uvm.h>
+
+/*
+ * functions
+ */
+
+/*
+ * uvm_io: perform I/O on a map
+ *
+ * => caller must have a reference to "map" so that it doesn't go away
+ *    while we are working.
+ */
+
+int
+uvm_io(map, uio)
+	vm_map_t map;
+	struct uio *uio;
+{
+	vaddr_t baseva, endva, pageoffset, kva;
+	vsize_t chunksz, togo, sz;
+	vm_map_entry_t dead_entries;
+	int error;
+
+	/*
+	 * step 0: sanity checks and set up for copy loop.  start with a
+	 * large chunk size.  if we have trouble finding vm space we will
+	 * reduce it.
+	 */
+
+	if (uio->uio_resid == 0)
+		return(0);
+	togo = uio->uio_resid;
+
+	baseva = (vaddr_t) uio->uio_offset;
+	endva = baseva + (togo - 1);
+
+	if (endva < baseva)   /* wrap around? */
+		return(EIO);
+
+	if (baseva >= VM_MAXUSER_ADDRESS)
+		return(0);
+	if (endva >= VM_MAXUSER_ADDRESS)
+		/* EOF truncate */
+		togo = togo - (endva - VM_MAXUSER_ADDRESS + 1);
+	pageoffset = baseva & PAGE_MASK;
+	baseva = trunc_page(baseva);
+	chunksz = min(round_page(togo + pageoffset), MAXBSIZE);
+	error = 0;
+
+	/*
+	 * step 1: main loop...  while we've got data to move
+	 */
+
+	for (/*null*/; togo > 0 ; pageoffset = 0) {
+
+		/*
+		 * step 2: extract mappings from the map into kernel_map
+		 */
+
+		error = uvm_map_extract(map, baseva, chunksz, kernel_map, &kva,
+			    UVM_EXTRACT_QREF | UVM_EXTRACT_CONTIG | 
+			    UVM_EXTRACT_FIXPROT);
+		if (error) {
+
+			/* retry with a smaller chunk... */
+			if (error == ENOMEM && chunksz > PAGE_SIZE) {
+				chunksz = trunc_page(chunksz / 2);
+				if (chunksz < PAGE_SIZE)
+					chunksz = PAGE_SIZE;
+				continue;
+			}
+
+			break;
+		}
+
+		/*
+		 * step 3: move a chunk of data
+		 */
+
+		sz = chunksz - pageoffset;
+		if (sz > togo)
+			sz = togo;
+		error = uiomove((caddr_t) (kva + pageoffset), sz, uio);
+		if (error)
+			break;
+		togo -= sz;
+		baseva += chunksz;
+
+
+		/*
+		 * step 4: unmap the area of kernel memory
+		 */
+
+		vm_map_lock(kernel_map);
+		(void)uvm_unmap_remove(kernel_map, kva, kva+chunksz,
+		    &dead_entries);
+		vm_map_unlock(kernel_map);
+
+		if (dead_entries != NULL)
+			uvm_unmap_detach(dead_entries, AMAP_REFALL);
+	}
+
+	/*
+	 * done
+	 */
+
+	return (error);
+}