uio: provide vm access to UIO_MEM_PHYS maps

This makes it possible to let gdb access mappings of the process that is
being debugged.

uio_mmap_logical was moved and uio_vm_ops renamed to group related code
and differentiate to new stuff.

CRs-Fixed: 570735
Change-Id: I8a5ff343727cc58fedfeb73f3466cc9a7f153e84
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 7294151d
Git-repo: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git


Signed-off-by: Pratibhasagar V <pratibha@codeaurora.org>
Signed-off-by: Ed Tam <etam@google.com>

drivers/uio/uio.c

@@ -640,12 +640,26 @@ static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	return 0;
 }
 
-static const struct vm_operations_struct uio_vm_ops = {
+static const struct vm_operations_struct uio_logical_vm_ops = {
 	.open = uio_vma_open,
 	.close = uio_vma_close,
 	.fault = uio_vma_fault,
 };
 
+static int uio_mmap_logical(struct vm_area_struct *vma)
+{
+	vma->vm_flags |= VM_DONTEXPAND | VM_NODUMP;
+	vma->vm_ops = &uio_logical_vm_ops;
+	uio_vma_open(vma);
+	return 0;
+}
+
+static const struct vm_operations_struct uio_physical_vm_ops = {
+#ifdef CONFIG_HAVE_IOREMAP_PROT
+	.access = generic_access_phys,
+#endif
+};
+
 static int uio_mmap_physical(struct vm_area_struct *vma)
 {
 	struct uio_device *idev = vma->vm_private_data;
@@ -653,7 +667,7 @@ static int uio_mmap_physical(struct vm_area_struct *vma)
 	if (mi < 0)
 		return -EINVAL;
 
-	vma->vm_flags |= VM_IO | VM_RESERVED;
+	vma->vm_ops = &uio_physical_vm_ops;
 
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
@@ -664,14 +678,6 @@ static int uio_mmap_physical(struct vm_area_struct *vma)
 			       vma->vm_page_prot);
 }
 
-static int uio_mmap_logical(struct vm_area_struct *vma)
-{
-	vma->vm_flags |= VM_RESERVED;
-	vma->vm_ops = &uio_vm_ops;
-	uio_vma_open(vma);
-	return 0;
-}
-
 static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
 {
 	struct uio_listener *listener = filep->private_data;