51 lines
1.5 KiB
C
51 lines
1.5 KiB
C
/*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* 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, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*
|
|
* Copyright (C) IBM Corporation, 2011
|
|
*
|
|
* Authors: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
|
|
* Anton Blanchard <anton@au.ibm.com>
|
|
*/
|
|
#include <linux/uaccess.h>
|
|
#include <linux/hardirq.h>
|
|
|
|
int enter_vmx_copy(void)
|
|
{
|
|
if (in_interrupt())
|
|
return 0;
|
|
|
|
/* This acts as preempt_disable() as well and will make
|
|
* enable_kernel_altivec(). We need to disable page faults
|
|
* as they can call schedule and thus make us lose the VMX
|
|
* context. So on page faults, we just fail which will cause
|
|
* a fallback to the normal non-vmx copy.
|
|
*/
|
|
pagefault_disable();
|
|
|
|
enable_kernel_altivec();
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* This function must return 0 because we tail call optimise when calling
|
|
* from __copy_tofrom_user_power7 which returns 0 on success.
|
|
*/
|
|
int exit_vmx_copy(void)
|
|
{
|
|
pagefault_enable();
|
|
return 0;
|
|
}
|