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123 lines
2.6 KiB
123 lines
2.6 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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#ifndef _ASM_PARISC_FUTEX_H |
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#define _ASM_PARISC_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/atomic.h> |
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#include <asm/errno.h> |
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/* The following has to match the LWS code in syscall.S. We have |
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sixteen four-word locks. */ |
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static inline void |
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_futex_spin_lock_irqsave(u32 __user *uaddr, unsigned long int *flags) |
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{ |
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extern u32 lws_lock_start[]; |
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long index = ((long)uaddr & 0x3f8) >> 1; |
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arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index]; |
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local_irq_save(*flags); |
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arch_spin_lock(s); |
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} |
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static inline void |
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_futex_spin_unlock_irqrestore(u32 __user *uaddr, unsigned long int *flags) |
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{ |
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extern u32 lws_lock_start[]; |
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long index = ((long)uaddr & 0x3f8) >> 1; |
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arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index]; |
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arch_spin_unlock(s); |
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local_irq_restore(*flags); |
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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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unsigned long int flags; |
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int oldval, ret; |
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u32 tmp; |
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_futex_spin_lock_irqsave(uaddr, &flags); |
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ret = -EFAULT; |
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if (unlikely(get_user(oldval, uaddr) != 0)) |
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goto out_pagefault_enable; |
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ret = 0; |
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tmp = oldval; |
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switch (op) { |
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case FUTEX_OP_SET: |
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tmp = oparg; |
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break; |
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case FUTEX_OP_ADD: |
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tmp += oparg; |
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break; |
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case FUTEX_OP_OR: |
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tmp |= oparg; |
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break; |
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case FUTEX_OP_ANDN: |
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tmp &= ~oparg; |
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break; |
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case FUTEX_OP_XOR: |
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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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if (ret == 0 && unlikely(put_user(tmp, uaddr) != 0)) |
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ret = -EFAULT; |
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out_pagefault_enable: |
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_futex_spin_unlock_irqrestore(uaddr, &flags); |
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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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u32 val; |
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unsigned long flags; |
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/* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is |
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* our gateway page, and causes no end of trouble... |
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*/ |
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if (uaccess_kernel() && !uaddr) |
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return -EFAULT; |
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if (!access_ok(uaddr, sizeof(u32))) |
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return -EFAULT; |
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/* HPPA has no cmpxchg in hardware and therefore the |
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* best we can do here is use an array of locks. The |
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* lock selected is based on a hash of the userspace |
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* address. This should scale to a couple of CPUs. |
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*/ |
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_futex_spin_lock_irqsave(uaddr, &flags); |
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if (unlikely(get_user(val, uaddr) != 0)) { |
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_futex_spin_unlock_irqrestore(uaddr, &flags); |
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return -EFAULT; |
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} |
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if (val == oldval && unlikely(put_user(newval, uaddr) != 0)) { |
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_futex_spin_unlock_irqrestore(uaddr, &flags); |
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return -EFAULT; |
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} |
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*uval = val; |
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_futex_spin_unlock_irqrestore(uaddr, &flags); |
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return 0; |
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} |
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#endif /*__KERNEL__*/ |
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#endif /*_ASM_PARISC_FUTEX_H*/
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