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/*
* SPU mm fault handler
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2007
*
* Author: Arnd Bergmann <arndb@de.ibm.com>
* Author: Jeremy Kerr <jk@ozlabs.org>
*
* 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <asm/spu.h>
#include <asm/spu_csa.h>
/*
* This ought to be kept in sync with the powerpc specific do_page_fault
* function. Currently, there are a few corner cases that we haven't had
* to handle fortunately.
*/
int spu_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
unsigned long dsisr, unsigned *flt)
{
struct vm_area_struct *vma;
unsigned long is_write;
int ret;
#if 0
if (!IS_VALID_EA(ea)) {
return -EFAULT;
}
#endif /* XXX */
if (mm == NULL) {
return -EFAULT;
}
if (mm->pgd == NULL) {
return -EFAULT;
}
down_read(&mm->mmap_sem);
vma = find_vma(mm, ea);
if (!vma)
goto bad_area;
if (vma->vm_start <= ea)
goto good_area;
if (!(vma->vm_flags & VM_GROWSDOWN))
goto bad_area;
if (expand_stack(vma, ea))
goto bad_area;
good_area:
is_write = dsisr & MFC_DSISR_ACCESS_PUT;
if (is_write) {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
} else {
if (dsisr & MFC_DSISR_ACCESS_DENIED)
goto bad_area;
if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
goto bad_area;
}
ret = 0;
*flt = handle_mm_fault(mm, vma, ea, is_write);
if (unlikely(*flt & VM_FAULT_ERROR)) {
if (*flt & VM_FAULT_OOM) {
ret = -ENOMEM;
goto bad_area;
} else if (*flt & VM_FAULT_SIGBUS) {
ret = -EFAULT;
goto bad_area;
}
BUG();
}
if (*flt & VM_FAULT_MAJOR)
current->maj_flt++;
else
current->min_flt++;
up_read(&mm->mmap_sem);
return ret;
bad_area:
up_read(&mm->mmap_sem);
return -EFAULT;
}
EXPORT_SYMBOL_GPL(spu_handle_mm_fault);
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