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
70