uio: introduce UIO_MEM_IOVA

mainline inclusion
from mainline-v4.20-rc1
commit bfddabfa
category: bugfix
bugzilla: 180968
CVE: NA

-------------------------------------------------

Introduce the concept of mapping physical memory locations that
are normal memory. The new type UIO_MEM_IOVA are similar to
existing UIO_MEM_PHYS but the backing memory is not marked as uncached.

Also, indent related switch to the currently used style.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Huang <chenhuang5@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/uio/uio.c

@@ -738,7 +738,8 @@ static int uio_mmap_physical(struct vm_area_struct *vma)
 		return -EINVAL;
 
 	vma->vm_ops = &uio_physical_vm_ops;
-	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+	if (idev->info->mem[mi].memtype == UIO_MEM_PHYS)
+		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
 	/*
 	 * We cannot use the vm_iomap_memory() helper here,
@@ -795,18 +796,19 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
 	}
 
 	switch (idev->info->mem[mi].memtype) {
-		case UIO_MEM_PHYS:
-			ret = uio_mmap_physical(vma);
-			break;
-		case UIO_MEM_LOGICAL:
-		case UIO_MEM_VIRTUAL:
-			ret = uio_mmap_logical(vma);
-			break;
-		default:
-			ret = -EINVAL;
+	case UIO_MEM_IOVA:
+	case UIO_MEM_PHYS:
+		ret = uio_mmap_physical(vma);
+		break;
+	case UIO_MEM_LOGICAL:
+	case UIO_MEM_VIRTUAL:
+		ret = uio_mmap_logical(vma);
+		break;
+	default:
+		ret = -EINVAL;
 	}
 
-out:
+ out:
 	mutex_unlock(&idev->info_lock);
 	return ret;
 }

include/linux/uio_driver.h

@@ -133,6 +133,7 @@ extern void uio_event_notify(struct uio_info *info);
 #define UIO_MEM_PHYS	1
 #define UIO_MEM_LOGICAL	2
 #define UIO_MEM_VIRTUAL 3
+#define UIO_MEM_IOVA	4
 
 /* defines for uio_port->porttype */
 #define UIO_PORT_NONE	0