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- /*
- * Copyright 2011 Tilera Corporation. All Rights Reserved.
- *
- * 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, version 2.
- *
- * This program 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, GOOD TITLE or
- * NON INFRINGEMENT. See the GNU General Public License for
- * more details.
- *
- * Atomically access user memory, but use MMU to avoid propagating
- * kernel exceptions.
- */
- #include <linux/linkage.h>
- #include <asm/errno.h>
- #include <asm/futex.h>
- #include <asm/page.h>
- #include <asm/processor.h>
- /*
- * Provide a set of atomic memory operations supporting <asm/futex.h>.
- *
- * r0: user address to manipulate
- * r1: new value to write, or for cmpxchg, old value to compare against
- * r2: (cmpxchg only) new value to write
- *
- * Return __get_user struct, r0 with value, r1 with error.
- */
- #define FUTEX_OP(name, ...) \
- STD_ENTRY(futex_##name) \
- __VA_ARGS__; \
- { \
- move r1, zero; \
- jrp lr \
- }; \
- STD_ENDPROC(futex_##name); \
- .pushsection __ex_table,"a"; \
- .quad 1b, get_user_fault; \
- .popsection
- .pushsection .fixup,"ax"
- get_user_fault:
- { movei r1, -EFAULT; jrp lr }
- ENDPROC(get_user_fault)
- .popsection
- FUTEX_OP(cmpxchg, mtspr CMPEXCH_VALUE, r1; 1: cmpexch4 r0, r0, r2)
- FUTEX_OP(set, 1: exch4 r0, r0, r1)
- FUTEX_OP(add, 1: fetchadd4 r0, r0, r1)
- FUTEX_OP(or, 1: fetchor4 r0, r0, r1)
- FUTEX_OP(andn, nor r1, r1, zero; 1: fetchand4 r0, r0, r1)
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