diff options
Diffstat (limited to 'include/asm-powerpc/futex.h')
-rw-r--r-- | include/asm-powerpc/futex.h | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/include/asm-powerpc/futex.h b/include/asm-powerpc/futex.h new file mode 100644 index 000000000000..f0319d50b129 --- /dev/null +++ b/include/asm-powerpc/futex.h @@ -0,0 +1,85 @@ +#ifndef _ASM_POWERPC_FUTEX_H +#define _ASM_POWERPC_FUTEX_H + +#ifdef __KERNEL__ + +#include <linux/futex.h> +#include <asm/errno.h> +#include <asm/synch.h> +#include <asm/uaccess.h> +#include <asm/asm-compat.h> + +#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ + __asm__ __volatile ( \ + SYNC_ON_SMP \ +"1: lwarx %0,0,%2\n" \ + insn \ + PPC405_ERR77(0, %2) \ +"2: stwcx. %1,0,%2\n" \ + "bne- 1b\n" \ + "li %1,0\n" \ +"3: .section .fixup,\"ax\"\n" \ +"4: li %1,%3\n" \ + "b 3b\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + ".align 3\n" \ + PPC_LONG "1b,4b,2b,4b\n" \ + ".previous" \ + : "=&r" (oldval), "=&r" (ret) \ + : "b" (uaddr), "i" (-EFAULT), "1" (oparg) \ + : "cr0", "memory") + +static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) +{ + int op = (encoded_op >> 28) & 7; + int cmp = (encoded_op >> 24) & 15; + int oparg = (encoded_op << 8) >> 20; + int cmparg = (encoded_op << 20) >> 20; + int oldval = 0, ret; + if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) + oparg = 1 << oparg; + + if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) + return -EFAULT; + + inc_preempt_count(); + + switch (op) { + case FUTEX_OP_SET: + __futex_atomic_op("", ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_ADD: + __futex_atomic_op("add %1,%0,%1\n", ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_OR: + __futex_atomic_op("or %1,%0,%1\n", ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_ANDN: + __futex_atomic_op("andc %1,%0,%1\n", ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_XOR: + __futex_atomic_op("xor %1,%0,%1\n", ret, oldval, uaddr, oparg); + break; + default: + ret = -ENOSYS; + } + + dec_preempt_count(); + + if (!ret) { + switch (cmp) { + case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break; + case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break; + case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break; + case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break; + case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break; + case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break; + default: ret = -ENOSYS; + } + } + return ret; +} + +#endif /* __KERNEL__ */ +#endif /* _ASM_POWERPC_FUTEX_H */ |