linux-stable/arch/powerpc/mm/copro_fault.c
Ian Munsie 4c6d9acce1 powerpc/mm: Add hooks for cxl
This adds hooks into the core powerpc mm code for cxl.

The core powerpc code sometimes uses local tlbie. Unfortunately this won't
work with the current cxl driver as it relies on snooping tlbie broadcasts.

The cxl hardware can have TLB entries invalidated via MMIO but this is not
currently supported by the driver. In future we can make local tlbie smarter so
that it invalidates cxl contexts via MMIO when it needs to but for now we have
this workaround.

This workaround checks for any active cxl contexts and if so, disables local
tlbie.

This also adds a hook for when SLBs are invalidated. This ensures any
corresponding SLBs in cxl are also invalidated at the same time. This is
required for segment demotion.

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 20:15:55 +11:00

149 lines
3.6 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>
#include <asm/spu.h>
#include <misc/cxl.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);
void copro_flush_all_slbs(struct mm_struct *mm)
{
#ifdef CONFIG_SPU_BASE
spu_flush_all_slbs(mm);
#endif
cxl_slbia(mm);
}
EXPORT_SYMBOL_GPL(copro_flush_all_slbs);