From: Nick Piggin Signed-off-by: Nick Piggin Acked-by: Jes Sorensen Signed-off-by: Andrew Morton --- drivers/char/mspec.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff -puN drivers/char/mspec.c~mspec-convert-nopfn-to-fault drivers/char/mspec.c --- a/drivers/char/mspec.c~mspec-convert-nopfn-to-fault +++ a/drivers/char/mspec.c @@ -193,25 +193,24 @@ mspec_close(struct vm_area_struct *vma) } /* - * mspec_nopfn + * mspec_fault * * Creates a mspec page and maps it to user space. */ -static unsigned long -mspec_nopfn(struct vm_area_struct *vma, unsigned long address) +static int +mspec_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { unsigned long paddr, maddr; unsigned long pfn; + pgoff_t index = vmf->pgoff; int index; struct vma_data *vdata = vma->vm_private_data; - BUG_ON(address < vdata->vm_start || address >= vdata->vm_end); - index = (address - vdata->vm_start) >> PAGE_SHIFT; maddr = (volatile unsigned long) vdata->maddr[index]; if (maddr == 0) { maddr = uncached_alloc_page(numa_node_id(), 1); if (maddr == 0) - return NOPFN_OOM; + return VM_FAULT_OOM; spin_lock(&vdata->lock); if (vdata->maddr[index] == 0) { @@ -231,13 +230,20 @@ mspec_nopfn(struct vm_area_struct *vma, pfn = paddr >> PAGE_SHIFT; - return pfn; + /* + * vm_insert_pfn can fail with -EBUSY, but in that case it will + * be because another thread has installed the pte first, so it + * is no problem. + */ + vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn); + + return VM_FAULT_NOPAGE; } static struct vm_operations_struct mspec_vm_ops = { .open = mspec_open, .close = mspec_close, - .nopfn = mspec_nopfn + .fault = mspec_fault, }; /* _