vm_object: Modify various drivers to allocate OBJT_SWAP objects

This is in preparation for removal of OBJT_DEFAULT.  In particular, it
is now cheap to check whether an OBJT_SWAP object has any swap blocks
allocated, so the benefit of having a separate OBJT_DEFAULT type is
quite marginal, and the OBJT_DEFAULT->SWAP transition is a source of
bugs.

Reviewed by:	alc, hselasky, kib
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D35779

sys/amd64/vmm/vmm.c

@@ -697,7 +697,7 @@ vm_alloc_memseg(struct vm *vm, int ident, size_t len, bool sysmem)
 			return (EINVAL);
 	}
 
-	obj = vm_object_allocate(OBJT_DEFAULT, len >> PAGE_SHIFT);
+	obj = vm_object_allocate(OBJT_SWAP, len >> PAGE_SHIFT);
 	if (obj == NULL)
 		return (ENOMEM);
 

sys/compat/linuxkpi/common/src/linux_shmemfs.c

@@ -84,7 +84,7 @@ linux_shmem_file_setup(const char *name, loff_t size, unsigned long flags)
 
 	filp->f_count = 1;
 	filp->f_vnode = vp;
-	filp->f_shmem = vm_pager_allocate(OBJT_DEFAULT, NULL, size,
+	filp->f_shmem = vm_pager_allocate(OBJT_SWAP, NULL, size,
 	    VM_PROT_READ | VM_PROT_WRITE, 0, curthread->td_ucred);
 	if (filp->f_shmem == NULL) {
 		error = -ENOMEM;

sys/dev/agp/agp.c

@@ -514,7 +514,7 @@ agp_generic_alloc_memory(device_t dev, int type, vm_size_t size)
 	mem->am_id = sc->as_nextid++;
 	mem->am_size = size;
 	mem->am_type = 0;
-	mem->am_obj = vm_object_allocate(OBJT_DEFAULT, atop(round_page(size)));
+	mem->am_obj = vm_object_allocate(OBJT_SWAP, atop(round_page(size)));
 	mem->am_physical = 0;
 	mem->am_offset = 0;
 	mem->am_is_bound = 0;

sys/dev/agp/agp_i810.c

@@ -1744,7 +1744,7 @@ agp_i810_alloc_memory(device_t dev, int type, vm_size_t size)
 	mem->am_size = size;
 	mem->am_type = type;
 	if (type != 1 && (type != 2 || size == AGP_PAGE_SIZE))
-		mem->am_obj = vm_object_allocate(OBJT_DEFAULT,
+		mem->am_obj = vm_object_allocate(OBJT_SWAP,
 		    atop(round_page(size)));
 	else
 		mem->am_obj = 0;

sys/dev/drm2/drm_gem.c

@@ -111,7 +111,7 @@ int drm_gem_object_init(struct drm_device *dev,
 	    ("Bad size %ju", (uintmax_t)size));
 
 	obj->dev = dev;
-	obj->vm_obj = vm_pager_allocate(OBJT_DEFAULT, NULL, size,
+	obj->vm_obj = vm_pager_allocate(OBJT_SWAP, NULL, size,
 	    VM_PROT_READ | VM_PROT_WRITE, 0, curthread->td_ucred);
 
 	obj->refcount = 1;