[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / powerpc / platforms / cell / spu_fault.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/export.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 | VM_FAULT_SIGSEGV)) {
			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);
Commit	Line	Data
7cd58e43 JK	1	/*
	2	* SPU mm fault handler
	3	*
	4	* (C) Copyright IBM Deutschland Entwicklung GmbH 2007
	5	*
	6	* Author: Arnd Bergmann <arndb@de.ibm.com>
	7	* Author: Jeremy Kerr <jk@ozlabs.org>
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License as published by
	11	* the Free Software Foundation; either version 2, or (at your option)
	12	* any later version.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License
	20	* along with this program; if not, write to the Free Software
	21	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	22	*/
	23	#include <linux/sched.h>
	24	#include <linux/mm.h>
4b16f8e2	25	#include <linux/export.h>
7cd58e43 JK	26
	27	#include <asm/spu.h>
	28	#include <asm/spu_csa.h>
	29
	30	/*
	31	* This ought to be kept in sync with the powerpc specific do_page_fault
	32	* function. Currently, there are a few corner cases that we haven't had
	33	* to handle fortunately.
	34	*/
	35	int spu_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
	36	unsigned long dsisr, unsigned *flt)
	37	{
	38	struct vm_area_struct *vma;
	39	unsigned long is_write;
	40	int ret;
	41
60ee0319	42	if (mm == NULL)
7cd58e43	43	return -EFAULT;
60ee0319 JK	44
60ee0319 JK	45	if (mm->pgd == NULL)
7cd58e43	46	return -EFAULT;
7cd58e43 JK	47
7cd58e43 JK	48	down_read(&mm->mmap_sem);
60ee0319	49	ret = -EFAULT;
7cd58e43 JK	50	vma = find_vma(mm, ea);
7cd58e43 JK	51	if (!vma)
60ee0319 JK	52	goto out_unlock;
	53
	54	if (ea < vma->vm_start) {
	55	if (!(vma->vm_flags & VM_GROWSDOWN))
	56	goto out_unlock;
	57	if (expand_stack(vma, ea))
	58	goto out_unlock;
	59	}
	60
7cd58e43 JK	61	is_write = dsisr & MFC_DSISR_ACCESS_PUT;
	62	if (is_write) {
	63	if (!(vma->vm_flags & VM_WRITE))
60ee0319	64	goto out_unlock;
7cd58e43 JK	65	} else {
7cd58e43 JK	66	if (dsisr & MFC_DSISR_ACCESS_DENIED)
60ee0319	67	goto out_unlock;
7cd58e43	68	if (!(vma->vm_flags & (VM_READ \| VM_EXEC)))
60ee0319	69	goto out_unlock;
7cd58e43	70	}
60ee0319	71
7cd58e43	72	ret = 0;
d06063cc	73	*flt = handle_mm_fault(mm, vma, ea, is_write ? FAULT_FLAG_WRITE : 0);
7cd58e43 JK	74	if (unlikely(*flt & VM_FAULT_ERROR)) {
	75	if (*flt & VM_FAULT_OOM) {
	76	ret = -ENOMEM;
60ee0319	77	goto out_unlock;
0c42d1fb	78	} else if (*flt & (VM_FAULT_SIGBUS \| VM_FAULT_SIGSEGV)) {
7cd58e43	79	ret = -EFAULT;
60ee0319	80	goto out_unlock;
7cd58e43 JK	81	}
	82	BUG();
	83	}
60ee0319	84
7cd58e43 JK	85	if (*flt & VM_FAULT_MAJOR)
	86	current->maj_flt++;
	87	else
	88	current->min_flt++;
7cd58e43	89
60ee0319	90	out_unlock:
7cd58e43	91	up_read(&mm->mmap_sem);
60ee0319	92	return ret;
7cd58e43 JK	93	}
7cd58e43 JK	94	EXPORT_SYMBOL_GPL(spu_handle_mm_fault);