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