1 /*
2 * fixmap.h: compile-time virtual memory allocation
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (C) 1998 Ingo Molnar
9 *
10 * Copyright 2008 Freescale Semiconductor Inc.
11 * Port to powerpc added by Kumar Gala
12 *
13 * Copyright 2011 Michal Simek <monstr@monstr.eu>
14 * Copyright 2011 PetaLogix Qld Pty Ltd
15 * Port to Microblaze
16 */
17
18 #ifndef _ASM_FIXMAP_H
19 #define _ASM_FIXMAP_H
20
21 #ifndef __ASSEMBLY__
22 #include <linux/kernel.h>
23 #include <asm/page.h>
24 #ifdef CONFIG_HIGHMEM
25 #include <linux/threads.h>
26 #include <asm/kmap_types.h>
27 #endif
28
29 #define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE))
30
31 /*
32 * Here we define all the compile-time 'special' virtual
33 * addresses. The point is to have a constant address at
34 * compile time, but to set the physical address only
35 * in the boot process. We allocate these special addresses
36 * from the end of virtual memory (0xfffff000) backwards.
37 * Also this lets us do fail-safe vmalloc(), we
38 * can guarantee that these special addresses and
39 * vmalloc()-ed addresses never overlap.
40 *
41 * these 'compile-time allocated' memory buffers are
42 * fixed-size 4k pages. (or larger if used with an increment
43 * highger than 1) use fixmap_set(idx,phys) to associate
44 * physical memory with fixmap indices.
45 *
46 * TLB entries of such buffers will not be flushed across
47 * task switches.
48 */
49 enum fixed_addresses {
50 FIX_HOLE,
51 #ifdef CONFIG_HIGHMEM
52 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
53 FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * num_possible_cpus()) - 1,
54 #endif
55 __end_of_fixed_addresses
56 };
57
58 extern void __set_fixmap(enum fixed_addresses idx,
59 phys_addr_t phys, pgprot_t flags);
60
61 #define __FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
62 #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
63
64 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_CI
65
66 #include <asm-generic/fixmap.h>
67
68 #endif /* !__ASSEMBLY__ */
69 #endif