1 | /* Low-level functions for atomic operations. ix86 version, x >= 4. |
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2 | Copyright (C) 1997, 2000, 2001 Free Software Foundation, Inc. |
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3 | This file is part of the GNU C Library. |
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4 | |
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5 | The GNU C Library is free software; you can redistribute it and/or |
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6 | modify it under the terms of the GNU Lesser General Public |
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7 | License as published by the Free Software Foundation; either |
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8 | version 2.1 of the License, or (at your option) any later version. |
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9 | |
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10 | The GNU C Library is distributed in the hope that it will be useful, |
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11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 | Lesser General Public License for more details. |
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14 | |
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15 | You should have received a copy of the GNU Lesser General Public |
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16 | License along with the GNU C Library; if not, write to the Free |
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17 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
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18 | 02111-1307 USA. */ |
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19 | |
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20 | #ifndef _ATOMICITY_H |
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21 | #define _ATOMICITY_H 1 |
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22 | |
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23 | |
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24 | |
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25 | static inline uint32_t |
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26 | __attribute__ ((__unused__)) |
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27 | exchange_and_add (volatile uint32_t *mem, uint32_t val) |
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28 | { |
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29 | register uint32_t result; |
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30 | __asm__ __volatile__ ("lock; xaddl %0,%1" |
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31 | : "=r" (result), "=m" (*mem) : "m" (val), "1" (*mem)); |
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32 | return result; |
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33 | } |
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34 | |
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35 | static inline void |
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36 | __attribute__ ((__unused__)) |
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37 | atomic_add (volatile uint32_t *mem, int val) |
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38 | { |
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39 | __asm__ __volatile__ ("lock; addl %1,%0" |
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40 | : "=m" (*mem) : "ir" (val), "m" (*mem)); |
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41 | } |
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42 | |
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43 | static inline char |
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44 | __attribute__ ((__unused__)) |
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45 | compare_and_swap (volatile long int *p, long int oldval, long int newval) |
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46 | { |
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47 | char ret; |
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48 | long int readval; |
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49 | |
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50 | __asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0" |
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51 | : "=q" (ret), "=m" (*p), "=a" (readval) |
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52 | : "r" (newval), "1" (*p), "a" (oldval)); |
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53 | return ret; |
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54 | } |
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55 | |
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56 | #endif /* atomicity.h */ |
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