95 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			95 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * 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 (mm == NULL)
 | |
| 		return -EFAULT;
 | |
| 
 | |
| 	if (mm->pgd == NULL)
 | |
| 		return -EFAULT;
 | |
| 
 | |
| 	down_read(&mm->mmap_sem);
 | |
| 	ret = -EFAULT;
 | |
| 	vma = find_vma(mm, ea);
 | |
| 	if (!vma)
 | |
| 		goto out_unlock;
 | |
| 
 | |
| 	if (ea < vma->vm_start) {
 | |
| 		if (!(vma->vm_flags & VM_GROWSDOWN))
 | |
| 			goto out_unlock;
 | |
| 		if (expand_stack(vma, ea))
 | |
| 			goto out_unlock;
 | |
| 	}
 | |
| 
 | |
| 	is_write = dsisr & MFC_DSISR_ACCESS_PUT;
 | |
| 	if (is_write) {
 | |
| 		if (!(vma->vm_flags & VM_WRITE))
 | |
| 			goto out_unlock;
 | |
| 	} else {
 | |
| 		if (dsisr & MFC_DSISR_ACCESS_DENIED)
 | |
| 			goto out_unlock;
 | |
| 		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
 | |
| 			goto out_unlock;
 | |
| 	}
 | |
| 
 | |
| 	ret = 0;
 | |
| 	*flt = handle_mm_fault(mm, vma, ea, is_write ? FAULT_FLAG_WRITE : 0);
 | |
| 	if (unlikely(*flt & VM_FAULT_ERROR)) {
 | |
| 		if (*flt & VM_FAULT_OOM) {
 | |
| 			ret = -ENOMEM;
 | |
| 			goto out_unlock;
 | |
| 		} else if (*flt & VM_FAULT_SIGBUS) {
 | |
| 			ret = -EFAULT;
 | |
| 			goto out_unlock;
 | |
| 		}
 | |
| 		BUG();
 | |
| 	}
 | |
| 
 | |
| 	if (*flt & VM_FAULT_MAJOR)
 | |
| 		current->maj_flt++;
 | |
| 	else
 | |
| 		current->min_flt++;
 | |
| 
 | |
| out_unlock:
 | |
| 	up_read(&mm->mmap_sem);
 | |
| 	return ret;
 | |
| }
 | |
| EXPORT_SYMBOL_GPL(spu_handle_mm_fault);
 |