xref: /netbsd-src/sys/external/bsd/drm2/include/linux/mm.h (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /*	$NetBSD: mm.h,v 1.2 2014/03/18 18:20:43 riastradh Exp $	*/
2 
3 /*-
4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Taylor R. Campbell.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef _LINUX_MM_H_
33 #define _LINUX_MM_H_
34 
35 #include <sys/kauth.h>
36 #include <sys/file.h>
37 #include <sys/mman.h>
38 #include <sys/proc.h>
39 #include <sys/vnode.h>
40 
41 #include <uvm/uvm_extern.h>
42 
43 /* XXX Ugh bletch!  Whattakludge!  Linux's sense is reversed...  */
44 #undef	PAGE_MASK
45 #define	PAGE_MASK	(~(PAGE_SIZE-1))
46 
47 #define	PAGE_ALIGN(x)		(((x) + (PAGE_SIZE-1)) & ~(PAGE_SIZE-1))
48 #define	offset_in_page(x)	((x) & (PAGE_SIZE-1))
49 
50 /*
51  * ###################################################################
52  * ############### XXX THIS NEEDS SERIOUS SCRUTINY XXX ###############
53  * ###################################################################
54  */
55 
56 /*
57  * XXX unsigned long is a loser but will probably work accidentally.
58  * XXX struct file might not map quite right between Linux and NetBSD.
59  * XXX This is large enough it should take its own file.
60  */
61 
62 static inline unsigned long
63 vm_mmap(struct file *file, unsigned long base, unsigned long size,
64     unsigned long prot, unsigned long flags, unsigned long token)
65 {
66 	struct vnode *vnode;
67 	vaddr_t addr;
68 	int error;
69 
70 	/*
71 	 * Cargo-culted from sys_mmap.  Various conditions kasserted
72 	 * rather than checked for expedience and safey.
73 	 */
74 
75 	KASSERT(base == 0);
76 	KASSERT(prot == (PROT_READ | PROT_WRITE));
77 	KASSERT(flags == MAP_SHARED);
78 
79 	KASSERT(file->f_type == DTYPE_VNODE);
80 	vnode = file->f_data;
81 
82 	KASSERT(vnode->v_type == VCHR);
83 	KASSERT((file->f_flag & (FREAD | FWRITE)) == (FREAD | FWRITE));
84 
85 	{
86 		struct vattr va;
87 
88 		vn_lock(vnode, (LK_SHARED | LK_RETRY));
89 		error = VOP_GETATTR(vnode, &va, kauth_cred_get());
90 		VOP_UNLOCK(vnode);
91 		if (error)
92 			goto out;
93 		/* XXX kassert?  */
94 		if ((va.va_flags & (SF_SNAPSHOT | IMMUTABLE | APPEND)) != 0) {
95 			error = EACCES;
96 			goto out;
97 		}
98 	}
99 
100 	/* XXX pax_mprotect?  pax_aslr?  */
101 
102 	addr = (*curproc->p_emul->e_vm_default_addr)(curproc,
103 	    (vaddr_t)curproc->p_vmspace->vm_daddr, size);
104 	error = uvm_mmap(&curproc->p_vmspace->vm_map, &addr, size,
105 	    (VM_PROT_READ | VM_PROT_WRITE), (VM_PROT_READ | VM_PROT_WRITE),
106 	    MAP_SHARED, vnode, base,
107 	    curproc->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
108 	if (error)
109 		goto out;
110 
111 	KASSERT(addr <= -1024UL); /* XXX Kludgerosity!  */
112 
113 out:	/* XXX errno NetBSD->Linux (kludgerific) */
114 	return (error? (-error) : (unsigned long)addr);
115 }
116 
117 #endif  /* _LINUX_MM_H_ */
118