| yuezonghe | 824eb0c | 2024-06-27 02:32:26 -0700 | [diff] [blame^] | 1 | /* Machine-dependent pthreads configuration and inline functions. |
| 2 | Copyright (C) 1996, 1998, 2000, 2002 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | Contributed by Richard Henderson <rth@tamu.edu>. |
| 5 | |
| 6 | The GNU C Library is free software; you can redistribute it and/or |
| 7 | modify it under the terms of the GNU Lesser General Public License as |
| 8 | published by the Free Software Foundation; either version 2.1 of the |
| 9 | License, or (at your option) any later version. |
| 10 | |
| 11 | The GNU C Library is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | Lesser General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU Lesser General Public |
| 17 | License along with the GNU C Library; see the file COPYING.LIB. If |
| 18 | not, write to the Free Software Foundation, Inc., |
| 19 | 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | #ifndef _PT_MACHINE_H |
| 22 | #define _PT_MACHINE_H 1 |
| 23 | |
| 24 | #include <features.h> |
| 25 | |
| 26 | #ifndef PT_EI |
| 27 | # define PT_EI __extern_always_inline |
| 28 | #endif |
| 29 | |
| 30 | #include <asm/fixed_code.h> |
| 31 | |
| 32 | /* Spinlock implementation; required. */ |
| 33 | /* The semantics of the TESTSET instruction cannot be guaranteed. We cannot |
| 34 | easily move all locks used by linux kernel to non-cacheable memory. |
| 35 | EXCPT 0x4 is used to trap into kernel to do the atomic testandset. |
| 36 | It's ugly. But it's the only thing we can do now. |
| 37 | The handler of EXCPT 0x4 expects the address of the lock is passed through |
| 38 | R0. And the result is returned by R0. */ |
| 39 | PT_EI long int |
| 40 | testandset (int *spinlock) |
| 41 | { |
| 42 | long int res; |
| 43 | |
| 44 | __asm__ __volatile__ ( |
| 45 | "CALL (%4);" |
| 46 | : "=q0" (res), "=m" (*spinlock) |
| 47 | : "qA" (spinlock), "m" (*spinlock), "a" (ATOMIC_XCHG32), "q1" (1) |
| 48 | : "RETS", "cc", "memory"); |
| 49 | |
| 50 | return res; |
| 51 | } |
| 52 | |
| 53 | #define HAS_COMPARE_AND_SWAP |
| 54 | PT_EI int |
| 55 | __compare_and_swap (long int *p, long int oldval, long int newval) |
| 56 | { |
| 57 | long int readval; |
| 58 | __asm__ __volatile__ ( |
| 59 | "CALL (%5);" |
| 60 | : "=q0" (readval), "=m" (*p) |
| 61 | : "qA" (p), |
| 62 | "q1" (oldval), |
| 63 | "q2" (newval), |
| 64 | "a" (ATOMIC_CAS32), |
| 65 | "m" (*p) |
| 66 | : "RETS", "memory", "cc"); |
| 67 | return readval == oldval; |
| 68 | } |
| 69 | |
| 70 | #ifdef SHARED |
| 71 | # define PTHREAD_STATIC_FN_REQUIRE(name) |
| 72 | #else |
| 73 | # define PTHREAD_STATIC_FN_REQUIRE(name) __asm__ (".globl " "_"#name); |
| 74 | #endif |
| 75 | |
| 76 | #endif /* pt-machine.h */ |