84 lines
1.9 KiB
C
84 lines
1.9 KiB
C
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#ifndef _ASM_FUTEX_H
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#define _ASM_FUTEX_H
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#ifdef __KERNEL__
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#include <linux/futex.h>
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#include <asm/errno.h>
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#include <asm/memory.h>
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#include <asm/uaccess.h>
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#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
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__asm__ __volatile (SYNC_ON_SMP \
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"1: lwarx %0,0,%2\n" \
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insn \
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"2: stwcx. %1,0,%2\n\
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bne- 1b\n\
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li %1,0\n\
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3: .section .fixup,\"ax\"\n\
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4: li %1,%3\n\
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b 3b\n\
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.previous\n\
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.section __ex_table,\"a\"\n\
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.align 3\n\
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.llong 1b,4b,2b,4b\n\
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.previous" \
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: "=&r" (oldval), "=&r" (ret) \
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: "b" (uaddr), "i" (-EFAULT), "1" (oparg) \
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: "cr0", "memory")
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static inline int
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futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
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{
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int op = (encoded_op >> 28) & 7;
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int cmp = (encoded_op >> 24) & 15;
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int oparg = (encoded_op << 8) >> 20;
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int cmparg = (encoded_op << 20) >> 20;
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int oldval = 0, ret;
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if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
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oparg = 1 << oparg;
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if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
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return -EFAULT;
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inc_preempt_count();
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switch (op) {
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case FUTEX_OP_SET:
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__futex_atomic_op("", ret, oldval, uaddr, oparg);
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break;
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case FUTEX_OP_ADD:
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__futex_atomic_op("add %1,%0,%1\n", ret, oldval, uaddr, oparg);
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break;
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case FUTEX_OP_OR:
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__futex_atomic_op("or %1,%0,%1\n", ret, oldval, uaddr, oparg);
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break;
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case FUTEX_OP_ANDN:
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__futex_atomic_op("andc %1,%0,%1\n", ret, oldval, uaddr, oparg);
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break;
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case FUTEX_OP_XOR:
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__futex_atomic_op("xor %1,%0,%1\n", ret, oldval, uaddr, oparg);
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break;
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default:
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ret = -ENOSYS;
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}
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dec_preempt_count();
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if (!ret) {
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switch (cmp) {
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case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
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case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
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case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
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case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
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case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
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case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
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default: ret = -ENOSYS;
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}
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}
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return ret;
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}
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#endif
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#endif
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