Add uvm_objwire() and uvm_objunwire(), I need this for some of my crazy

shitz.

Code mostly from netbsd with some tweaks from me. The loaning case is
specifcically if 0ed out right now because we do not do loaning.

ok ariane@, art@.

1 files changed, 159 insertions, 0 deletions

diff --git a/sys/uvm/uvm_object.c b/sys/uvm/uvm_object.c
new file mode 100644
index 00000000000..9eaaf575f50
--- /dev/null
+++ b/sys/uvm/uvm_object.c
@@ -0,0 +1,159 @@
+/*	$OpenBSD: uvm_object.c,v 1.1 2009/06/06 03:45:08 oga Exp $	*/
+
+/*
+ * Copyright (c) 2006 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Mindaugas Rasiukevicius.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+/*
+ * uvm_object.c: operate with memory objects
+ *
+ */
+
+#include <sys/cdefs.h>
+
+#include <sys/param.h>
+
+#include <uvm/uvm.h>
+
+/* We will fetch this page count per step */
+#define	FETCH_PAGECOUNT	16
+
+/*
+ * uvm_objwire: wire the pages of entire uobj
+ *
+ * => caller must pass page-aligned start and end values
+ * => if the caller passes in a pageq pointer, we'll return a list of
+ *  wired pages.
+ */
+
+int
+uvm_objwire(struct uvm_object *uobj, off_t start, off_t end,
+    struct pglist *pageq)
+{
+	int i, npages, error;
+	struct vm_page *pgs[FETCH_PAGECOUNT];
+	off_t offset = start, left;
+
+	left = (end - start) >> PAGE_SHIFT;
+
+	simple_lock(&uobj->vmobjlock);
+	while (left) {
+
+		npages = MIN(FETCH_PAGECOUNT, left);
+
+		/* Get the pages */
+		memset(pgs, 0, sizeof(pgs));
+		error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0,
+			VM_PROT_READ | VM_PROT_WRITE, UVM_ADV_SEQUENTIAL,
+			PGO_ALLPAGES | PGO_SYNCIO);
+
+		if (error)
+			goto error;
+
+		simple_lock(&uobj->vmobjlock);
+		for (i = 0; i < npages; i++) {
+
+			KASSERT(pgs[i] != NULL);
+			KASSERT(!(pgs[i]->pg_flags & PG_RELEASED));
+
+#if 0
+			/*
+			 * Loan break
+			 */
+			if (pgs[i]->loan_count) {
+				while (pgs[i]->loan_count) {
+					pg = uvm_loanbreak(pgs[i]);
+					if (!pg) {
+						simple_unlock(&uobj->vmobjlock);
+						uvm_wait("uobjwirepg");
+						simple_lock(&uobj->vmobjlock);
+						continue;
+					}
+				}
+				pgs[i] = pg;
+			}
+#endif
+
+			if (pgs[i]->pg_flags & PQ_AOBJ) {
+				atomic_clearbits_int(&pgs[i]->pg_flags,
+				    PG_CLEAN);
+				uao_dropswap(uobj, i);
+			}
+		}
+
+		/* Wire the pages */
+		uvm_lock_pageq();
+		for (i = 0; i < npages; i++) {
+			uvm_pagewire(pgs[i]);
+			if (pageq != NULL)
+				TAILQ_INSERT_TAIL(pageq, pgs[i], pageq);
+		}
+		uvm_unlock_pageq();
+
+		/* Unbusy the pages */
+		uvm_page_unbusy(pgs, npages);
+
+		left -= npages;
+		offset += npages << PAGE_SHIFT;
+	}
+	simple_unlock(&uobj->vmobjlock);
+
+	return 0;
+
+error:
+	/* Unwire the pages which have been wired */
+	uvm_objunwire(uobj, start, offset);
+
+	return error;
+}
+
+/*
+ * uobj_unwirepages: unwire the pages of entire uobj
+ *
+ * => caller must pass page-aligned start and end values
+ */
+
+void
+uvm_objunwire(struct uvm_object *uobj, off_t start, off_t end)
+{
+	struct vm_page *pg;
+	off_t offset;
+
+	simple_lock(&uobj->vmobjlock);
+	uvm_lock_pageq();
+	for (offset = start; offset < end; offset += PAGE_SIZE) {
+		pg = uvm_pagelookup(uobj, offset);
+
+		KASSERT(pg != NULL);
+		KASSERT(!(pg->pg_flags & PG_RELEASED));
+
+		uvm_pageunwire(pg);
+	}
+	uvm_unlock_pageq();
+	simple_unlock(&uobj->vmobjlock);
+}