mirror of
https://github.com/torvalds/linux
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103 lines
2.4 KiB
C
103 lines
2.4 KiB
C
#ifndef _ASM_FUTEX_H
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#define _ASM_FUTEX_H
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#ifdef __KERNEL__
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#include <linux/config.h>
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#include <linux/futex.h>
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#include <asm/errno.h>
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#include <asm/uaccess.h>
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#ifdef CONFIG_SMP
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#define __FUTEX_SMP_SYNC " sync \n"
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#else
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#define __FUTEX_SMP_SYNC
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#endif
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#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
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{ \
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__asm__ __volatile__( \
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" .set push \n" \
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" .set noat \n" \
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" .set mips3 \n" \
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"1: ll %1, (%3) # __futex_atomic_op1 \n" \
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" .set mips0 \n" \
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" " insn " \n" \
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" .set mips3 \n" \
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"2: sc $1, (%3) \n" \
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" beqzl $1, 1b \n" \
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__FUTEX_SMP_SYNC \
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"3: \n" \
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" .set pop \n" \
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" .set mips0 \n" \
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" .section .fixup,\"ax\" \n" \
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"4: li %0, %5 \n" \
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" j 2b \n" \
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" .previous \n" \
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" .section __ex_table,\"a\" \n" \
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" "__UA_ADDR "\t1b, 4b \n" \
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" "__UA_ADDR "\t2b, 4b \n" \
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" .previous \n" \
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: "=r" (ret), "=r" (oldval) \
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: "0" (0), "r" (uaddr), "Jr" (oparg), "i" (-EFAULT)); \
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}
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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("move $1, %z4", ret, oldval, uaddr, oparg);
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break;
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case FUTEX_OP_ADD:
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__futex_atomic_op("addu $1, %1, %z4",
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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, %1, %z4",
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ret, oldval, uaddr, oparg);
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break;
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case FUTEX_OP_ANDN:
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__futex_atomic_op("and $1, %1, %z4",
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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, %1, %z4",
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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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