108 lines
2.4 KiB
C
108 lines
2.4 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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*/
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#ifndef _ASM_FUTEX_H
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#define _ASM_FUTEX_H
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#include <linux/futex.h>
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#include <linux/uaccess.h>
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#include <asm/barrier.h>
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#include <asm/errno.h>
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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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"1: ll.w %1, %4 # __futex_atomic_op\n" \
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" " insn " \n" \
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"2: sc.w $t0, %2 \n" \
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" beqz $t0, 1b \n" \
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"3: \n" \
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" .section .fixup,\"ax\" \n" \
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"4: li.w %0, %6 \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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" "__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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"=ZC" (*uaddr) \
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: "0" (0), "ZC" (*uaddr), "Jr" (oparg), \
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"i" (-EFAULT) \
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: "memory", "t0"); \
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}
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static inline int
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arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
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{
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int oldval = 0, ret = 0;
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pagefault_disable();
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switch (op) {
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case FUTEX_OP_SET:
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__futex_atomic_op("move $t0, %z5", 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.w $t0, %1, %z5", 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 $t0, %1, %z5", 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 $t0, %1, %z5", 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 $t0, %1, %z5", 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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pagefault_enable();
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if (!ret)
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*oval = oldval;
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return ret;
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}
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static inline int
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futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval)
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{
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int ret = 0;
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u32 val = 0;
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if (!access_ok(uaddr, sizeof(u32)))
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return -EFAULT;
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__asm__ __volatile__(
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"# futex_atomic_cmpxchg_inatomic \n"
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"1: ll.w %1, %3 \n"
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" bne %1, %z4, 3f \n"
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" move $t0, %z5 \n"
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"2: sc.w $t0, %2 \n"
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" beqz $t0, 1b \n"
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"3: \n"
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__WEAK_LLSC_MB
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" .section .fixup,\"ax\" \n"
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"4: li.d %0, %6 \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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" "__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" (val), "=ZC" (*uaddr)
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: "ZC" (*uaddr), "Jr" (oldval), "Jr" (newval),
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"i" (-EFAULT)
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: "memory", "t0");
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*uval = val;
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return ret;
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}
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#endif /* _ASM_FUTEX_H */
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