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Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation 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 see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
134 lines
2.9 KiB
C
134 lines
2.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2012 ARM Ltd.
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*/
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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 <linux/uaccess.h>
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#include <asm/errno.h>
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#define FUTEX_MAX_LOOPS 128 /* What's the largest number you can think of? */
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#define __futex_atomic_op(insn, ret, oldval, uaddr, tmp, oparg) \
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do { \
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unsigned int loops = FUTEX_MAX_LOOPS; \
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\
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uaccess_enable(); \
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asm volatile( \
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" prfm pstl1strm, %2\n" \
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"1: ldxr %w1, %2\n" \
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insn "\n" \
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"2: stlxr %w0, %w3, %2\n" \
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" cbz %w0, 3f\n" \
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" sub %w4, %w4, %w0\n" \
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" cbnz %w4, 1b\n" \
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" mov %w0, %w7\n" \
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"3:\n" \
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" dmb ish\n" \
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" .pushsection .fixup,\"ax\"\n" \
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" .align 2\n" \
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"4: mov %w0, %w6\n" \
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" b 3b\n" \
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" .popsection\n" \
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_ASM_EXTABLE(1b, 4b) \
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_ASM_EXTABLE(2b, 4b) \
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: "=&r" (ret), "=&r" (oldval), "+Q" (*uaddr), "=&r" (tmp), \
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"+r" (loops) \
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: "r" (oparg), "Ir" (-EFAULT), "Ir" (-EAGAIN) \
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: "memory"); \
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uaccess_disable(); \
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} while (0)
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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, tmp;
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u32 __user *uaddr = __uaccess_mask_ptr(_uaddr);
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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("mov %w3, %w5",
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ret, oldval, uaddr, tmp, oparg);
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break;
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case FUTEX_OP_ADD:
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__futex_atomic_op("add %w3, %w1, %w5",
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ret, oldval, uaddr, tmp, oparg);
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break;
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case FUTEX_OP_OR:
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__futex_atomic_op("orr %w3, %w1, %w5",
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ret, oldval, uaddr, tmp, oparg);
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break;
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case FUTEX_OP_ANDN:
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__futex_atomic_op("and %w3, %w1, %w5",
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ret, oldval, uaddr, tmp, ~oparg);
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break;
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case FUTEX_OP_XOR:
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__futex_atomic_op("eor %w3, %w1, %w5",
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ret, oldval, uaddr, tmp, 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,
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u32 oldval, u32 newval)
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{
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int ret = 0;
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unsigned int loops = FUTEX_MAX_LOOPS;
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u32 val, tmp;
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u32 __user *uaddr;
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if (!access_ok(_uaddr, sizeof(u32)))
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return -EFAULT;
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uaddr = __uaccess_mask_ptr(_uaddr);
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uaccess_enable();
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asm volatile("// futex_atomic_cmpxchg_inatomic\n"
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" prfm pstl1strm, %2\n"
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"1: ldxr %w1, %2\n"
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" sub %w3, %w1, %w5\n"
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" cbnz %w3, 4f\n"
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"2: stlxr %w3, %w6, %2\n"
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" cbz %w3, 3f\n"
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" sub %w4, %w4, %w3\n"
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" cbnz %w4, 1b\n"
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" mov %w0, %w8\n"
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"3:\n"
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" dmb ish\n"
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"4:\n"
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" .pushsection .fixup,\"ax\"\n"
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"5: mov %w0, %w7\n"
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" b 4b\n"
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" .popsection\n"
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_ASM_EXTABLE(1b, 5b)
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_ASM_EXTABLE(2b, 5b)
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: "+r" (ret), "=&r" (val), "+Q" (*uaddr), "=&r" (tmp), "+r" (loops)
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: "r" (oldval), "r" (newval), "Ir" (-EFAULT), "Ir" (-EAGAIN)
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: "memory");
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uaccess_disable();
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if (!ret)
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*uval = val;
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return ret;
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}
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#endif /* __KERNEL__ */
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#endif /* __ASM_FUTEX_H */
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