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| /*
| * atomic64_t for 586+
| *
| * Copyright © 2010 Luca Barbieri
| *
| * This program is free software; you can redistribute it and/or modify
| * it under the terms of the GNU General Public License as published by
| * the Free Software Foundation; either version 2 of the License, or
| * (at your option) any later version.
| */
|
| #include <linux/linkage.h>
| #include <asm/alternative-asm.h>
|
| .macro read64 reg
| movl %ebx, %eax
| movl %ecx, %edx
| /* we need LOCK_PREFIX since otherwise cmpxchg8b always does the write */
| LOCK_PREFIX
| cmpxchg8b (\reg)
| .endm
|
| ENTRY(atomic64_read_cx8)
| read64 %ecx
| ret
| ENDPROC(atomic64_read_cx8)
|
| ENTRY(atomic64_set_cx8)
| 1:
| /* we don't need LOCK_PREFIX since aligned 64-bit writes
| * are atomic on 586 and newer */
| cmpxchg8b (%esi)
| jne 1b
|
| ret
| ENDPROC(atomic64_set_cx8)
|
| ENTRY(atomic64_xchg_cx8)
| 1:
| LOCK_PREFIX
| cmpxchg8b (%esi)
| jne 1b
|
| ret
| ENDPROC(atomic64_xchg_cx8)
|
| .macro addsub_return func ins insc
| ENTRY(atomic64_\func\()_return_cx8)
| pushl %ebp
| pushl %ebx
| pushl %esi
| pushl %edi
|
| movl %eax, %esi
| movl %edx, %edi
| movl %ecx, %ebp
|
| read64 %ecx
| 1:
| movl %eax, %ebx
| movl %edx, %ecx
| \ins\()l %esi, %ebx
| \insc\()l %edi, %ecx
| LOCK_PREFIX
| cmpxchg8b (%ebp)
| jne 1b
|
| 10:
| movl %ebx, %eax
| movl %ecx, %edx
| popl %edi
| popl %esi
| popl %ebx
| popl %ebp
| ret
| ENDPROC(atomic64_\func\()_return_cx8)
| .endm
|
| addsub_return add add adc
| addsub_return sub sub sbb
|
| .macro incdec_return func ins insc
| ENTRY(atomic64_\func\()_return_cx8)
| pushl %ebx
|
| read64 %esi
| 1:
| movl %eax, %ebx
| movl %edx, %ecx
| \ins\()l $1, %ebx
| \insc\()l $0, %ecx
| LOCK_PREFIX
| cmpxchg8b (%esi)
| jne 1b
|
| 10:
| movl %ebx, %eax
| movl %ecx, %edx
| popl %ebx
| ret
| ENDPROC(atomic64_\func\()_return_cx8)
| .endm
|
| incdec_return inc add adc
| incdec_return dec sub sbb
|
| ENTRY(atomic64_dec_if_positive_cx8)
| pushl %ebx
|
| read64 %esi
| 1:
| movl %eax, %ebx
| movl %edx, %ecx
| subl $1, %ebx
| sbb $0, %ecx
| js 2f
| LOCK_PREFIX
| cmpxchg8b (%esi)
| jne 1b
|
| 2:
| movl %ebx, %eax
| movl %ecx, %edx
| popl %ebx
| ret
| ENDPROC(atomic64_dec_if_positive_cx8)
|
| ENTRY(atomic64_add_unless_cx8)
| pushl %ebp
| pushl %ebx
| /* these just push these two parameters on the stack */
| pushl %edi
| pushl %ecx
|
| movl %eax, %ebp
| movl %edx, %edi
|
| read64 %esi
| 1:
| cmpl %eax, 0(%esp)
| je 4f
| 2:
| movl %eax, %ebx
| movl %edx, %ecx
| addl %ebp, %ebx
| adcl %edi, %ecx
| LOCK_PREFIX
| cmpxchg8b (%esi)
| jne 1b
|
| movl $1, %eax
| 3:
| addl $8, %esp
| popl %ebx
| popl %ebp
| ret
| 4:
| cmpl %edx, 4(%esp)
| jne 2b
| xorl %eax, %eax
| jmp 3b
| ENDPROC(atomic64_add_unless_cx8)
|
| ENTRY(atomic64_inc_not_zero_cx8)
| pushl %ebx
|
| read64 %esi
| 1:
| movl %eax, %ecx
| orl %edx, %ecx
| jz 3f
| movl %eax, %ebx
| xorl %ecx, %ecx
| addl $1, %ebx
| adcl %edx, %ecx
| LOCK_PREFIX
| cmpxchg8b (%esi)
| jne 1b
|
| movl $1, %eax
| 3:
| popl %ebx
| ret
| ENDPROC(atomic64_inc_not_zero_cx8)
|
|
