xref: /freebsd/sys/sys/devmap.h (revision 5df74441b35f2303ecdc7b79f9d331f5e77a07db)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2013 Ian Lepore <ian@freebsd.org>
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, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifndef	_SYS_DEVMAP_H_
30 #define	_SYS_DEVMAP_H_
31 
32 #ifndef _KERNEL
33 #error "no user-serviceable parts inside"
34 #endif
35 
36 /*
37  * This structure is used by MD code to describe static mappings of devices
38  * which are established as part of bringing up the MMU early in the boot.
39  */
40 struct devmap_entry {
41 	vm_offset_t	pd_va;		/* virtual address */
42 	vm_paddr_t	pd_pa;		/* physical address */
43 	vm_size_t	pd_size;	/* size of region */
44 };
45 
46 /*
47  * Return the lowest KVA address used in any entry in the registered devmap
48  * table.  This works with whatever table is registered, including the internal
49  * table used by devmap_add_entry() if that routine was used. Platforms can
50  * implement platform_lastaddr() by calling this if static device mappings are
51  * their only use of high KVA space.
52  */
53 vm_offset_t devmap_lastaddr(void);
54 
55 /*
56  * Automatically allocate KVA (from the top of the address space downwards) and
57  * make static device mapping entries in an internal table.  The internal table
58  * is automatically registered on the first call to this.
59  */
60 void devmap_add_entry(vm_paddr_t pa, vm_size_t sz);
61 
62 /*
63  * Register a platform-local table to be bootstrapped by the generic
64  * platform-specific init function in <ARCH>/machdep.c.  This is used by newer
65  * code that allocates and fills in its own local table but does not have its
66  * own platform-specific init routine.
67  */
68 void devmap_register_table(const struct devmap_entry * _table);
69 
70 /*
71  * Establish mappings for all the entries in the table.  This is called
72  * automatically from the common platform-specific init function in
73  * <ARCH>/machdep.c, and also from the custom platform-specific init routines
74  * in older code.  This function only has an effect when a table was installed
75  * previously by devmap_register_table().
76  */
77 void devmap_bootstrap(void);
78 
79 /*
80  * Translate between virtual and physical addresses within a region that is
81  * static-mapped by the devmap code.  If the given address range isn't
82  * static-mapped, then ptov returns NULL and vtop returns DEVMAP_PADDR_NOTFOUND.
83  * The latter implies that you can't vtop just the last byte of physical address
84  * space.  This is not as limiting as it might sound, because even if a device
85  * occupies the end of the physical address space, you're only prevented from
86  * doing vtop for that single byte.  If you vtop a size bigger than 1 it works.
87  */
88 #define	DEVMAP_PADDR_NOTFOUND	((vm_paddr_t)(-1))
89 
90 void *     devmap_ptov(vm_paddr_t _pa, vm_size_t _sz);
91 vm_paddr_t devmap_vtop(void * _va, vm_size_t _sz);
92 
93 /* Print the static mapping table; used for bootverbose output. */
94 void devmap_print_table(void);
95 
96 #endif /* !_SYS_DEVMAP_H_ */
97