alistair23-linux/arch/powerpc/mm/copro_fault.c
Ian Munsie 73d16a6e0e powerpc/cell: Move data segment faulting code out of cell platform
__spu_trap_data_seg() currently contains code to determine the VSID and ESID
required for a particular EA and mm struct.

This code is generically useful for other co-processors. This moves the code of
the cell platform so it can be used by other powerpc code. It also adds 1TB
segment handling which Cell didn't support.  The new function is called
copro_calculate_slb().

This also moves the internal struct spu_slb to a generic struct copro_slb which
is now used in the Cell and copro code.  We use this new struct instead of
passing around esid and vsid parameters.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-08 20:14:55 +11:00

139 lines
3.4 KiB
C

/*
* CoProcessor (SPU/AFU) 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/reg.h>
#include <asm/copro.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 copro_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 & DSISR_ISSTORE;
if (is_write) {
if (!(vma->vm_flags & VM_WRITE))
goto out_unlock;
} else {
if (dsisr & DSISR_PROTFAULT)
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(copro_handle_mm_fault);
int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
{
u64 vsid;
int psize, ssize;
slb->esid = (ea & ESID_MASK) | SLB_ESID_V;
switch (REGION_ID(ea)) {
case USER_REGION_ID:
pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
psize = get_slice_psize(mm, ea);
ssize = user_segment_size(ea);
vsid = get_vsid(mm->context.id, ea, ssize);
break;
case VMALLOC_REGION_ID:
pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
if (ea < VMALLOC_END)
psize = mmu_vmalloc_psize;
else
psize = mmu_io_psize;
ssize = mmu_kernel_ssize;
vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
break;
case KERNEL_REGION_ID:
pr_devel("%s: 0x%llx -- KERNEL_REGION_ID\n", __func__, ea);
psize = mmu_linear_psize;
ssize = mmu_kernel_ssize;
vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
break;
default:
pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
return 1;
}
vsid = (vsid << slb_vsid_shift(ssize)) | SLB_VSID_USER;
vsid |= mmu_psize_defs[psize].sllp |
((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
slb->vsid = vsid;
return 0;
}
EXPORT_SYMBOL_GPL(copro_calculate_slb);