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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 |