| 1 | 1275 | phoenix | /*
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         | 2 |  |  |  * fixmap.h: compile-time virtual memory allocation
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         | 3 |  |  |  *
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         | 4 |  |  |  * This file is subject to the terms and conditions of the GNU General Public
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         | 5 |  |  |  * License.  See the file "COPYING" in the main directory of this archive
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         | 6 |  |  |  * for more details.
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         | 7 |  |  |  *
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         | 8 |  |  |  * Copyright (C) 1998 Ingo Molnar
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         | 9 |  |  |  *
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         | 10 |  |  |  * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
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         | 11 |  |  |  */
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         | 12 |  |  |  
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         | 13 |  |  | #ifndef _ASM_FIXMAP_H
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         | 14 |  |  | #define _ASM_FIXMAP_H
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         | 15 |  |  |  
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         | 16 |  |  | #include <linux/config.h>
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         | 17 |  |  | #include <linux/kernel.h>
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         | 18 |  |  | #include <asm/apicdef.h>
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         | 19 |  |  | #include <asm/page.h>
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         | 20 |  |  | #include <asm/vsyscall.h>
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         | 21 |  |  |  
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         | 22 |  |  | /*
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         | 23 |  |  |  * Here we define all the compile-time 'special' virtual
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         | 24 |  |  |  * addresses. The point is to have a constant address at
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         | 25 |  |  |  * compile time, but to set the physical address only
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         | 26 |  |  |  * in the boot process.
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         | 27 |  |  |  *
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         | 28 |  |  |  * these 'compile-time allocated' memory buffers are
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         | 29 |  |  |  * fixed-size 4k pages. (or larger if used with an increment
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         | 30 |  |  |  * highger than 1) use fixmap_set(idx,phys) to associate
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         | 31 |  |  |  * physical memory with fixmap indices.
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         | 32 |  |  |  *
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         | 33 |  |  |  * TLB entries of such buffers will not be flushed across
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         | 34 |  |  |  * task switches.
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         | 35 |  |  |  */
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         | 36 |  |  |  
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         | 37 |  |  | enum fixed_addresses {
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         | 38 |  |  |         VSYSCALL_LAST_PAGE,
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         | 39 |  |  |         VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
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         | 40 |  |  |         VSYSCALL_HPET,
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         | 41 |  |  |         FIX_HPET_BASE,
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         | 42 |  |  | #ifdef CONFIG_X86_LOCAL_APIC
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         | 43 |  |  |         FIX_APIC_BASE,  /* local (CPU) APIC) -- required for SMP or not */
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         | 44 |  |  | #endif
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         | 45 |  |  | #ifdef CONFIG_X86_IO_APIC
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         | 46 |  |  |         FIX_IO_APIC_BASE_0,
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         | 47 |  |  |         FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS-1,
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         | 48 |  |  | #endif
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         | 49 |  |  |         __end_of_fixed_addresses
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         | 50 |  |  | };
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         | 51 |  |  |  
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         | 52 |  |  | extern void __set_fixmap (enum fixed_addresses idx,
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         | 53 |  |  |                                         unsigned long phys, pgprot_t flags);
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         | 54 |  |  |  
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         | 55 |  |  | #define set_fixmap(idx, phys) \
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         | 56 |  |  |                 __set_fixmap(idx, phys, PAGE_KERNEL)
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         | 57 |  |  | /*
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         | 58 |  |  |  * Some hardware wants to get fixmapped without caching.
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         | 59 |  |  |  */
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         | 60 |  |  | #define set_fixmap_nocache(idx, phys) \
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         | 61 |  |  |                 __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
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         | 62 |  |  |  
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         | 63 |  |  | #define FIXADDR_TOP     (VSYSCALL_END-PAGE_SIZE)
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         | 64 |  |  | #define FIXADDR_SIZE    (__end_of_fixed_addresses << PAGE_SHIFT)
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         | 65 |  |  | #define FIXADDR_START   (FIXADDR_TOP - FIXADDR_SIZE)
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         | 66 |  |  |  
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         | 67 |  |  | #define __fix_to_virt(x)        (FIXADDR_TOP - ((x) << PAGE_SHIFT))
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         | 68 |  |  |  
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         | 69 |  |  | extern void __this_fixmap_does_not_exist(void);
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         | 70 |  |  |  
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         | 71 |  |  | /*
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         | 72 |  |  |  * 'index to address' translation. If anyone tries to use the idx
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         | 73 |  |  |  * directly without tranlation, we catch the bug with a NULL-deference
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         | 74 |  |  |  * kernel oops. Illegal ranges of incoming indices are caught too.
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         | 75 |  |  |  */
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         | 76 |  |  | extern inline unsigned long fix_to_virt(const unsigned int idx)
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         | 77 |  |  | {
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         | 78 |  |  |         /*
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         | 79 |  |  |          * this branch gets completely eliminated after inlining,
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         | 80 |  |  |          * except when someone tries to use fixaddr indices in an
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         | 81 |  |  |          * illegal way. (such as mixing up address types or using
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         | 82 |  |  |          * out-of-range indices).
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         | 83 |  |  |          *
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         | 84 |  |  |          * If it doesn't get removed, the linker will complain
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         | 85 |  |  |          * loudly with a reasonably clear error message..
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         | 86 |  |  |          */
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         | 87 |  |  |         if (idx >= __end_of_fixed_addresses)
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         | 88 |  |  |                 __this_fixmap_does_not_exist();
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         | 89 |  |  |  
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         | 90 |  |  |         return __fix_to_virt(idx);
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         | 91 |  |  | }
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         | 92 |  |  |  
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         | 93 |  |  | #endif
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