1/*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2016 Matthew Macy (mmacy@mattmacy.io)
4 * Copyright (c) 2017 Mellanox Technologies, Ltd.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice unmodified, this list of conditions, and the following
12 *    disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/rwlock.h>
32
33#include <vm/vm.h>
34#include <vm/pmap.h>
35#include <vm/vm_object.h>
36#include <vm/vm_map.h>
37#include <vm/vm_page.h>
38#include <vm/vm_pager.h>
39
40#include <linux/fs.h>
41#include <linux/mm.h>
42#include <linux/shmem_fs.h>
43
44struct page *
45linux_shmem_read_mapping_page_gfp(vm_object_t obj, int pindex, gfp_t gfp)
46{
47	struct page *page;
48	int rv;
49
50	if ((gfp & GFP_NOWAIT) != 0)
51		panic("GFP_NOWAIT is unimplemented");
52
53	VM_OBJECT_WLOCK(obj);
54	rv = vm_page_grab_valid(&page, obj, pindex, VM_ALLOC_NORMAL |
55	    VM_ALLOC_NOBUSY | VM_ALLOC_WIRED);
56	VM_OBJECT_WUNLOCK(obj);
57	if (rv != VM_PAGER_OK)
58		return (ERR_PTR(-EINVAL));
59	return (page);
60}
61
62struct linux_file *
63linux_shmem_file_setup(const char *name, loff_t size, unsigned long flags)
64{
65	struct fileobj {
66		struct linux_file file __aligned(sizeof(void *));
67		struct vnode vnode __aligned(sizeof(void *));
68	};
69	struct fileobj *fileobj;
70	struct linux_file *filp;
71	struct vnode *vp;
72	int error;
73
74	fileobj = kzalloc(sizeof(*fileobj), GFP_KERNEL);
75	if (fileobj == NULL) {
76		error = -ENOMEM;
77		goto err_0;
78	}
79	filp = &fileobj->file;
80	vp = &fileobj->vnode;
81
82	filp->f_count = 1;
83	filp->f_vnode = vp;
84	filp->f_shmem = vm_pager_allocate(OBJT_SWAP, NULL, size,
85	    VM_PROT_READ | VM_PROT_WRITE, 0, curthread->td_ucred);
86	if (filp->f_shmem == NULL) {
87		error = -ENOMEM;
88		goto err_1;
89	}
90	return (filp);
91err_1:
92	kfree(filp);
93err_0:
94	return (ERR_PTR(error));
95}
96
97static vm_ooffset_t
98linux_invalidate_mapping_pages_sub(vm_object_t obj, vm_pindex_t start,
99    vm_pindex_t end, int flags)
100{
101	int start_count, end_count;
102
103	VM_OBJECT_WLOCK(obj);
104	start_count = obj->resident_page_count;
105	vm_object_page_remove(obj, start, end, flags);
106	end_count = obj->resident_page_count;
107	VM_OBJECT_WUNLOCK(obj);
108	return (start_count - end_count);
109}
110
111unsigned long
112linux_invalidate_mapping_pages(vm_object_t obj, pgoff_t start, pgoff_t end)
113{
114
115	return (linux_invalidate_mapping_pages_sub(obj, start, end, OBJPR_CLEANONLY));
116}
117
118void
119linux_shmem_truncate_range(vm_object_t obj, loff_t lstart, loff_t lend)
120{
121	vm_pindex_t start = OFF_TO_IDX(lstart + PAGE_SIZE - 1);
122	vm_pindex_t end = OFF_TO_IDX(lend + 1);
123
124	(void) linux_invalidate_mapping_pages_sub(obj, start, end, 0);
125}
126