| yuezonghe | 824eb0c | 2024-06-27 02:32:26 -0700 | [diff] [blame] | 1 | /* Machine-dependent pthreads configuration and inline functions. |
| 2 | * |
| 3 | * Copyright (C) 2005-2007 Atmel Corporation |
| 4 | * |
| 5 | * This file is subject to the terms and conditions of the GNU Lesser General |
| 6 | * Public License. See the file "COPYING.LIB" in the main directory of this |
| 7 | * archive for more details. |
| 8 | */ |
| 9 | #ifndef _PT_MACHINE_H |
| 10 | #define _PT_MACHINE_H 1 |
| 11 | |
| 12 | #include <features.h> |
| 13 | |
| 14 | #ifndef PT_EI |
| 15 | # define PT_EI __extern_always_inline |
| 16 | #endif |
| 17 | |
| 18 | static __inline__ int |
| 19 | _test_and_set (int *p, int v) |
| 20 | { |
| 21 | int result; |
| 22 | |
| 23 | __asm__ __volatile__( |
| 24 | "/* Inline test and set */\n" |
| 25 | " xchg %[old], %[mem], %[new]" |
| 26 | : [old] "=&r"(result) |
| 27 | : [mem] "r"(p), [new] "r"(v) |
| 28 | : "memory"); |
| 29 | |
| 30 | return result; |
| 31 | } |
| 32 | |
| 33 | extern long int testandset (int *spinlock); |
| 34 | extern int __compare_and_swap (long int *p, long int oldval, long int newval); |
| 35 | |
| 36 | /* Spinlock implementation; required. */ |
| 37 | PT_EI long int |
| 38 | testandset (int *spinlock) |
| 39 | { |
| 40 | return _test_and_set(spinlock, 1); |
| 41 | } |
| 42 | |
| 43 | |
| 44 | /* Get some notion of the current stack. Need not be exactly the top |
| 45 | of the stack, just something somewhere in the current frame. */ |
| 46 | #define CURRENT_STACK_FRAME stack_pointer |
| 47 | register char * stack_pointer __asm__ ("sp"); |
| 48 | |
| 49 | /* Compare-and-swap for semaphores. */ |
| 50 | |
| 51 | #define HAS_COMPARE_AND_SWAP |
| 52 | PT_EI int |
| 53 | __compare_and_swap(long int *p, long int oldval, long int newval) |
| 54 | { |
| 55 | long int result; |
| 56 | |
| 57 | __asm__ __volatile__( |
| 58 | "/* Inline compare and swap */\n" |
| 59 | "1: ssrf 5\n" |
| 60 | " ld.w %[result], %[mem]\n" |
| 61 | " eor %[result], %[old]\n" |
| 62 | " brne 2f\n" |
| 63 | " stcond %[mem], %[new]\n" |
| 64 | " brne 1b\n" |
| 65 | "2:" |
| 66 | : [result] "=&r"(result), [mem] "=m"(*p) |
| 67 | : "m"(*p), [new] "r"(newval), [old] "r"(oldval) |
| 68 | : "cc", "memory"); |
| 69 | |
| 70 | return result == 0; |
| 71 | } |
| 72 | |
| 73 | #endif /* pt-machine.h */ |