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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 141 | trimarchi | 1 | /* |
| 2 | * Some of this code has been taken from bitops.h |
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| 3 | * Copyright 1992, Linus Torvalds. |
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| 4 | * |
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| 5 | * Others functions has been added by |
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| 6 | * Miguel Masmano Tello <mmasmano@disca.upv.es> |
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| 7 | * Copyright (C) Feb, 2003 OCERA Consortium |
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| 8 | * Release under the terms of the GNU General Public License Version 2 |
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| 9 | */ |
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| 10 | |||
| 11 | #define ADDR (*(volatile long *) addr) |
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| 12 | |||
| 13 | /** |
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| 14 | * ffs - find first bit set |
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| 15 | * @x: the word to search |
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| 16 | * |
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| 17 | * This is defined the same way as |
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| 18 | * the libc and compiler builtin ffs routines, therefore |
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| 19 | * differs in spirit from the above ffz (man ffs). |
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| 20 | */ |
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| 21 | |||
| 22 | |||
| 23 | static __inline__ int DIDMA_ffs(int x) |
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| 24 | { |
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| 25 | int r; |
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| 26 | |||
| 27 | __asm__("bsfl %1,%0\n\t" |
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| 28 | "jnz 1f\n\t" |
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| 29 | "movl $-1,%0\n" |
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| 30 | "1:" : "=r" (r) : "g" (x)); |
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| 31 | return r; |
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| 32 | } |
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| 33 | |||
| 34 | |||
| 35 | /** |
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| 36 | * fls - find last bit set |
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| 37 | * @x: the word to search |
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| 38 | * |
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| 39 | * This is defined the same way as |
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| 40 | * the libc and compiler builtin ffs routines, therefore |
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| 41 | * differs in spirit from the above ffz (man ffs). |
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| 42 | */ |
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| 43 | static __inline__ int DIDMA_fls(int x) |
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| 44 | { |
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| 45 | int r; |
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| 46 | |||
| 47 | __asm__("bsrl %1,%0\n\t" |
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| 48 | "jnz 1f\n\t" |
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| 49 | "movl $-1,%0\n" |
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| 50 | "1:" : "=r" (r) : "g" (x)); |
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| 51 | return r; |
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| 52 | } |
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| 53 | |||
| 54 | /** |
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| 55 | * __set_bit - Set a bit in memory |
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| 56 | * @nr: the bit to set |
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| 57 | * @addr: the address to start counting from |
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| 58 | * |
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| 59 | * Unlike set_bit(), this function is non-atomic and may be reordered. |
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| 60 | * If it's called on the same region of memory simultaneously, the effect |
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| 61 | * may be that only one operation succeeds. |
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| 62 | */ |
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| 63 | /* |
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| 64 | static __inline__ void __set_bit(int nr, volatile void * addr) |
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| 65 | { |
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| 66 | __asm__( |
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| 67 | "btsl %1,%0" |
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| 68 | :"=m" (ADDR) |
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| 69 | :"Ir" (nr)); |
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| 70 | } |
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| 71 | */ |
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| 72 | /** |
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| 73 | * __clear_bit - Clears a bit in memory |
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| 74 | * @nr: Bit to clear |
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| 75 | * @addr: Address to start counting from |
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| 76 | * |
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| 77 | * clear_bit() is non-atomic and may be reordered. However, it does |
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| 78 | * not contain a memory barrier, so if it is used for locking purposes, |
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| 79 | * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit() |
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| 80 | * in order to ensure changes are visible on other processors. |
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| 81 | */ |
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| 82 | static __inline__ void __clear_bit(int nr, volatile void * addr) |
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| 83 | { |
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| 84 | __asm__ __volatile__( |
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| 85 | "btrl %1,%0" |
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| 86 | :"=m" (ADDR) |
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| 87 | :"Ir" (nr)); |
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| 88 | } |
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| 89 | |||
| 90 | |||
| 91 | |||
| 92 |