uio: introduce UIO_MEM_IOVA

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: Stephen Hemminger <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
soumdtt · Sep 25, 2018 · bfddabf · bfddabf
1 parent ae6935e
commit bfddabf
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Showing 2 changed files with 14 additions and 11 deletions.
diff --git a/drivers/uio/uio.c b/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;
 }

diff --git a/include/linux/uio_driver.h b/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