| /* Copyright (C) 2003-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <sysdep.h> |
| #include <lowlevellock.h> |
| #include <lowlevelrwlock.h> |
| #include <pthread-errnos.h> |
| #include <tcb-offsets.h> |
| #include <kernel-features.h> |
| #include "lowlevel-atomic.h" |
| |
| |
| .text |
| |
| .globl __pthread_rwlock_rdlock |
| .type __pthread_rwlock_rdlock,@function |
| .align 5 |
| cfi_startproc |
| __pthread_rwlock_rdlock: |
| mov.l r12, @-r15 |
| cfi_adjust_cfa_offset (4) |
| cfi_rel_offset (r12, 0) |
| mov.l r9, @-r15 |
| cfi_adjust_cfa_offset (4) |
| cfi_rel_offset (r9, 0) |
| mov.l r8, @-r15 |
| cfi_adjust_cfa_offset (4) |
| cfi_rel_offset (r8, 0) |
| sts.l pr, @-r15 |
| cfi_adjust_cfa_offset (4) |
| cfi_rel_offset (pr, 0) |
| mov r4, r8 |
| |
| /* Get the lock. */ |
| mov #0, r3 |
| mov #1, r4 |
| #if MUTEX == 0 |
| CMPXCHG (r3, @r8, r4, r2) |
| #else |
| CMPXCHG (r3, @(MUTEX,r8), r4, r2) |
| #endif |
| bf 1f |
| 2: |
| mov.l @(WRITER,r8), r0 |
| tst r0, r0 |
| bf 14f |
| mov.l @(WRITERS_QUEUED,r8), r0 |
| tst r0, r0 |
| bt 5f |
| mov #FLAGS, r0 |
| mov.b @(r0,r8), r0 |
| tst r0, r0 |
| bt 5f |
| 3: |
| mov.l @(READERS_QUEUED,r8), r0 |
| add #1, r0 |
| mov.l r0, @(READERS_QUEUED,r8) |
| tst r0, r0 |
| bt 4f |
| |
| mov.l @(READERS_WAKEUP,r8), r9 |
| |
| #if MUTEX == 0 |
| DEC (@r8, r2) |
| #else |
| DEC (@(MUTEX,r8), r2) |
| #endif |
| tst r2, r2 |
| bf 10f |
| 11: |
| #ifdef __ASSUME_PRIVATE_FUTEX |
| mov #PSHARED, r0 |
| mov.b @(r0,r8), r5 |
| mov #(FUTEX_PRIVATE_FLAG|FUTEX_WAIT), r0 |
| xor r0, r5 |
| extu.b r5, r5 |
| #else |
| mov #PSHARED, r0 |
| mov.b @(r0,r8), r5 |
| extu.b r5, r5 |
| # if FUTEX_WAIT != 0 |
| mov #FUTEX_WAIT, r0 |
| or r0, r5 |
| # endif |
| stc gbr, r1 |
| mov.w .Lpfoff, r2 |
| add r2, r1 |
| mov.l @r1, r0 |
| xor r0, r5 |
| #endif |
| mov r8, r4 |
| add #READERS_WAKEUP, r4 |
| mov r9, r6 |
| mov #0, r7 |
| mov #SYS_futex, r3 |
| extu.b r3, r3 |
| trapa #0x14 |
| SYSCALL_INST_PAD |
| |
| /* Reget the lock. */ |
| mov #0, r3 |
| mov #1, r4 |
| #if MUTEX == 0 |
| CMPXCHG (r3, @r8, r4, r2) |
| #else |
| CMPXCHG (r3, @(MUTEX,r8), r4, r2) |
| #endif |
| bf 12f |
| 13: |
| mov.l @(READERS_QUEUED,r8), r0 |
| add #-1, r0 |
| bra 2b |
| mov.l r0, @(READERS_QUEUED,r8) |
| |
| 5: |
| mov #0, r3 |
| mov.l @(NR_READERS,r8), r0 |
| add #1, r0 |
| mov.l r0, @(NR_READERS,r8) |
| tst r0, r0 |
| bt 8f |
| |
| 9: |
| #if MUTEX == 0 |
| DEC (@r8, r2) |
| #else |
| DEC (@(MUTEX,r8), r2) |
| #endif |
| tst r2, r2 |
| bf 6f |
| 7: |
| cfi_remember_state |
| lds.l @r15+, pr |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (pr) |
| mov.l @r15+, r8 |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (r8) |
| mov.l @r15+, r9 |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (r9) |
| mov.l @r15+, r12 |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (r12) |
| rts |
| mov r3, r0 |
| cfi_restore_state |
| |
| #ifndef __ASSUME_PRIVATE_FUTEX |
| .Lpfoff: |
| .word PRIVATE_FUTEX - TLS_PRE_TCB_SIZE |
| #endif |
| |
| 1: |
| mov r8, r5 |
| #if MUTEX != 0 |
| add #MUTEX, r5 |
| #endif |
| mov #PSHARED, r0 |
| mov.b @(r0,r8), r6 |
| extu.b r6, r6 |
| mov.l .Lwait0, r1 |
| bsrf r1 |
| mov r2, r4 |
| .Lwait0b: |
| bra 2b |
| nop |
| 14: |
| stc gbr, r1 |
| mov.w .Ltidoff, r2 |
| add r2, r1 |
| mov.l @r1, r1 |
| cmp/eq r1, r0 |
| bf 3b |
| /* Deadlock detected. */ |
| bra 9b |
| mov #EDEADLK, r3 |
| |
| .Ltidoff: |
| .word TID - TLS_PRE_TCB_SIZE |
| |
| 6: |
| mov r8, r4 |
| #if MUTEX != 0 |
| add #MUTEX, r4 |
| #endif |
| mov #PSHARED, r0 |
| mov.b @(r0,r8), r5 |
| extu.b r5, r5 |
| mov.l .Lwake0, r1 |
| bsrf r1 |
| nop |
| .Lwake0b: |
| bra 7b |
| mov #0, r3 |
| |
| 8: |
| /* Overflow. */ |
| mov.l @(NR_READERS,r8), r1 |
| add #-1, r1 |
| mov.l r1, @(NR_READERS,r8) |
| bra 9b |
| mov #EAGAIN, r3 |
| |
| 4: |
| /* Overflow. */ |
| mov.l @(READERS_QUEUED,r8), r1 |
| add #-1, r1 |
| mov.l r1, @(READERS_QUEUED,r8) |
| bra 9b |
| mov #EAGAIN, r3 |
| |
| 10: |
| mov r8, r4 |
| #if MUTEX != 0 |
| add #MUTEX, r4 |
| #endif |
| mov #PSHARED, r0 |
| mov.b @(r0,r8), r5 |
| extu.b r5, r5 |
| mov.l .Lwake1, r1 |
| bsrf r1 |
| nop |
| .Lwake1b: |
| bra 11b |
| nop |
| |
| 12: |
| mov r8, r5 |
| #if MUTEX != 0 |
| add #MUTEX, r5 |
| #endif |
| mov #PSHARED, r0 |
| mov.b @(r0,r8), r6 |
| extu.b r6, r6 |
| mov.l .Lwait1, r1 |
| bsrf r1 |
| mov r2, r4 |
| .Lwait1b: |
| bra 13b |
| nop |
| cfi_endproc |
| |
| .align 2 |
| .Lwait0: |
| .long __lll_lock_wait-.Lwait0b |
| .Lwake0: |
| .long __lll_unlock_wake-.Lwake0b |
| .Lwait1: |
| .long __lll_lock_wait-.Lwait1b |
| .Lwake1: |
| .long __lll_unlock_wake-.Lwake1b |
| .size __pthread_rwlock_rdlock,.-__pthread_rwlock_rdlock |
| |
| strong_alias (__pthread_rwlock_rdlock, pthread_rwlock_rdlock) |
| hidden_def (__pthread_rwlock_rdlock) |
