summaryrefslogtreecommitdiff
path: root/drivers/usb/core/usb.c
diff options
context:
space:
mode:
authorBorislav Petkov <bp@suse.de>2021-03-18 18:43:11 +0300
committerBorislav Petkov <bp@suse.de>2021-03-18 18:43:11 +0300
commitafb4a37778491eae010a43edebea32ff2d45f01c (patch)
treec40bcc6143e5542134477dd96a108d24b1f9074f /drivers/usb/core/usb.c
parent229164175ff0c61ff581e6bf37fbfcb608b6e9bb (diff)
parent1e28eed17697bcf343c6743f0028cc3b5dd88bf0 (diff)
downloadlinux-afb4a37778491eae010a43edebea32ff2d45f01c.tar.xz
Merge tag 'v5.12-rc3' into x86/seves
Pick up dependent SEV-ES urgent changes which went into -rc3 to base new work ontop. Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'drivers/usb/core/usb.c')
-rw-r--r--drivers/usb/core/usb.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 8f07b0516100..a566bb494e24 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -748,6 +748,38 @@ void usb_put_intf(struct usb_interface *intf)
}
EXPORT_SYMBOL_GPL(usb_put_intf);
+/**
+ * usb_intf_get_dma_device - acquire a reference on the usb interface's DMA endpoint
+ * @intf: the usb interface
+ *
+ * While a USB device cannot perform DMA operations by itself, many USB
+ * controllers can. A call to usb_intf_get_dma_device() returns the DMA endpoint
+ * for the given USB interface, if any. The returned device structure must be
+ * released with put_device().
+ *
+ * See also usb_get_dma_device().
+ *
+ * Returns: A reference to the usb interface's DMA endpoint; or NULL if none
+ * exists.
+ */
+struct device *usb_intf_get_dma_device(struct usb_interface *intf)
+{
+ struct usb_device *udev = interface_to_usbdev(intf);
+ struct device *dmadev;
+
+ if (!udev->bus)
+ return NULL;
+
+ dmadev = get_device(udev->bus->sysdev);
+ if (!dmadev || !dmadev->dma_mask) {
+ put_device(dmadev);
+ return NULL;
+ }
+
+ return dmadev;
+}
+EXPORT_SYMBOL_GPL(usb_intf_get_dma_device);
+
/* USB device locking
*
* USB devices and interfaces are locked using the semaphore in their