commit 17bcff4475474bcbfe6b709186250b42db7d2b6b
Author: Stacey Son <sson@FreeBSD.org>
Date:   Mon Feb 17 04:42:51 2014 -0600

    Move the machine dependent code parts out of vm_thread_new().
    
    This change moves the machine dependent code for allocating memory,
    for both virtual and physical, out of vm_thread_new().  The reason
    this code is machine dependent is the memory has to be contiguous
    and properly aligned for MIPS.  In the future it might be best if
    this code is moved to maybe the pmap layer or vm_machdep.c.

diff --git a/sys/mips/include/param.h b/sys/mips/include/param.h
index 264a847..0d6ffae 100644
--- a/sys/mips/include/param.h
+++ b/sys/mips/include/param.h
@@ -165,6 +165,9 @@
  * The kernel stack needs to be aligned on a (PAGE_SIZE * 2) boundary.
  */
 #define	KSTACK_PAGES		2	/* kernel stack */
+#define	KSTACK_SIZE		(KSTACK_PAGES * PAGE_SIZE)
+#define	KSTACK_PAGE_SIZE	PAGE_SIZE
+#define	KSTACK_PAGE_MASK	(PAGE_SIZE - 1)
 #define	KSTACK_GUARD_PAGES	2	/* pages of kstack guard; 0 disables */
 
 /*
diff --git a/sys/vm/vm_glue.c b/sys/vm/vm_glue.c
index ecd5d20..265e8c4 100644
--- a/sys/vm/vm_glue.c
+++ b/sys/vm/vm_glue.c
@@ -311,6 +311,89 @@ SYSCTL_INT(_vm, OID_AUTO, kstacks, CTLFLAG_RD, &kstacks, 0,
 #define KSTACK_MAX_PAGES 32
 #endif
 
+#if defined(__mips__)
+
+static vm_offset_t
+vm_kstack_valloc(int pages)
+{
+	vm_offset_t ks;
+
+	/*
+	 * We need to align the kstack's mapped address to fit within
+	 * a single TLB entry.
+	 */
+	if (vmem_xalloc(kernel_arena,
+	    (pages + KSTACK_GUARD_PAGES) * PAGE_SIZE,
+	    KSTACK_PAGE_SIZE * 2, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX,
+	    M_BESTFIT | M_NOWAIT, &ks)) {
+		return (0);
+	}
+
+	return (ks);
+}
+
+#define	KSTACK_OBJT		OBJT_DEFAULT
+
+static int
+vm_kstack_palloc(vm_object_t ksobj, vm_offset_t ks, int allocflags, int pages,
+    vm_page_t ma[])
+{
+	int i;
+
+	VM_OBJECT_ASSERT_WLOCKED(ksobj);
+
+	allocflags = (allocflags & ~VM_ALLOC_CLASS_MASK) | VM_ALLOC_NORMAL;
+
+	for (i = 0; i < pages; i++) {
+		/*
+		 * Get a kernel stack page.
+		 */
+		ma[i] = vm_page_grab(ksobj, i, allocflags);
+		if (allocflags & VM_ALLOC_NOBUSY)
+			ma[i]->valid = VM_PAGE_BITS_ALL;
+	}
+
+	return (i);
+}
+
+#else /* ! __mips__ */
+
+#define	KSTACK_OBJT		OBJT_DEFAULT
+
+static vm_offset_t
+vm_kstack_valloc(int pages)
+{
+	vm_offset_t ks;
+
+	ks = kva_alloc((pages + KSTACK_GUARD_PAGES) * PAGE_SIZE);
+
+	return(ks);
+}
+
+static int
+vm_kstack_palloc(vm_object_t ksobj, vm_offset_t ks, int allocflags, int pages,
+    vm_page_t ma[])
+{
+	int i;
+
+	VM_OBJECT_ASSERT_WLOCKED(ksobj);
+
+	allocflags = (allocflags & ~VM_ALLOC_CLASS_MASK) | VM_ALLOC_NORMAL;
+
+	for (i = 0; i < pages; i++) {
+		/*
+		 * Get a kernel stack page.
+		 */
+		ma[i] = vm_page_grab(ksobj, i, allocflags);
+		if (allocflags & VM_ALLOC_NOBUSY)
+			ma[i]->valid = VM_PAGE_BITS_ALL;
+	}
+
+	return (i);
+}
+#endif /* ! __mips__ */
+
+
 /*
  * Create the kernel stack (including pcb for i386) for a new thread.
  * This routine directly affects the fork perf for a process and
@@ -321,9 +404,8 @@ vm_thread_new(struct thread *td, int pages)
 {
 	vm_object_t ksobj;
 	vm_offset_t ks;
-	vm_page_t m, ma[KSTACK_MAX_PAGES];
+	vm_page_t ma[KSTACK_MAX_PAGES];
 	struct kstack_cache_entry *ks_ce;
-	int i;
 
 	/* Bounds check */
 	if (pages <= 1)
@@ -349,24 +431,12 @@ vm_thread_new(struct thread *td, int pages)
 	/*
 	 * Allocate an object for the kstack.
 	 */
-	ksobj = vm_object_allocate(OBJT_DEFAULT, pages);
-	
+	ksobj = vm_object_allocate(KSTACK_OBJT, pages);
+
 	/*
 	 * Get a kernel virtual address for this thread's kstack.
 	 */
-#if defined(__mips__)
-	/*
-	 * We need to align the kstack's mapped address to fit within
-	 * a single TLB entry.
-	 */
-	if (vmem_xalloc(kernel_arena, (pages + KSTACK_GUARD_PAGES) * PAGE_SIZE,
-	    PAGE_SIZE * 2, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX,
-	    M_BESTFIT | M_NOWAIT, &ks)) {
-		ks = 0;
-	}
-#else
-	ks = kva_alloc((pages + KSTACK_GUARD_PAGES) * PAGE_SIZE);
-#endif
+	ks = vm_kstack_valloc(pages);
 	if (ks == 0) {
 		printf("vm_thread_new: kstack allocation failed\n");
 		vm_object_deallocate(ksobj);
@@ -385,21 +455,15 @@ vm_thread_new(struct thread *td, int pages)
 	 * want to deallocate them.
 	 */
 	td->td_kstack_pages = pages;
-	/* 
-	 * For the length of the stack, link in a real page of ram for each
-	 * page of stack.
-	 */
+
 	VM_OBJECT_WLOCK(ksobj);
-	for (i = 0; i < pages; i++) {
-		/*
-		 * Get a kernel stack page.
-		 */
-		m = vm_page_grab(ksobj, i, VM_ALLOC_NOBUSY |
-		    VM_ALLOC_NORMAL | VM_ALLOC_WIRED);
-		ma[i] = m;
-		m->valid = VM_PAGE_BITS_ALL;
-	}
+	pages = vm_kstack_palloc(ksobj, ks, (VM_ALLOC_NOBUSY | VM_ALLOC_WIRED),
+	    pages, ma);
 	VM_OBJECT_WUNLOCK(ksobj);
+	if (pages == 0) {
+		printf("vm_thread_new: vm_kstack_palloc() failed\n");
+		return (0);
+	}
 	pmap_qenter(ks, ma, pages);
 	return (1);
 }
@@ -526,9 +590,8 @@ vm_thread_swapin(struct thread *td)
 	pages = td->td_kstack_pages;
 	ksobj = td->td_kstack_obj;
 	VM_OBJECT_WLOCK(ksobj);
-	for (i = 0; i < pages; i++)
-		ma[i] = vm_page_grab(ksobj, i, VM_ALLOC_NORMAL |
-		    VM_ALLOC_WIRED);
+	rv = vm_kstack_palloc(ksobj, td->td_kstack, VM_ALLOC_WIRED, pages, ma);
+	KASSERT(rv != 0, ("vm_thread_swapin: vm_kstack_palloc() failed"));
 	for (i = 0; i < pages; i++) {
 		if (ma[i]->valid != VM_PAGE_BITS_ALL) {
 			vm_page_assert_xbusied(ma[i]);