78 lines
1.9 KiB
C
78 lines
1.9 KiB
C
/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* Copyright (C) IBM Corporation, 2011
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*
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* Authors: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
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* Anton Blanchard <anton@au.ibm.com>
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*/
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#include <linux/uaccess.h>
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#include <linux/hardirq.h>
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#include <asm/switch_to.h>
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int enter_vmx_usercopy(void)
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{
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if (in_interrupt())
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return 0;
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preempt_disable();
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/*
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* We need to disable page faults as they can call schedule and
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* thus make us lose the VMX context. So on page faults, we just
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* fail which will cause a fallback to the normal non-vmx copy.
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*/
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pagefault_disable();
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enable_kernel_altivec();
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return 1;
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}
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/*
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* This function must return 0 because we tail call optimise when calling
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* from __copy_tofrom_user_power7 which returns 0 on success.
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*/
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int exit_vmx_usercopy(void)
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{
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disable_kernel_altivec();
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pagefault_enable();
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preempt_enable();
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return 0;
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}
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int enter_vmx_copy(void)
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{
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if (in_interrupt())
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return 0;
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preempt_disable();
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enable_kernel_altivec();
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return 1;
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}
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/*
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* All calls to this function will be optimised into tail calls. We are
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* passed a pointer to the destination which we return as required by a
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* memcpy implementation.
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*/
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void *exit_vmx_copy(void *dest)
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{
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disable_kernel_altivec();
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preempt_enable();
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return dest;
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}
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