USB EHCI/Xen: propagate controller reset information to hypervisor

Just like for the in-tree early console debug port driver, the
hypervisor - when using a debug port based console - also needs to be
told about controller resets, so it can suppress using and then
re-initialize the debug port accordingly.

Other than the in-tree driver, the hypervisor driver actually cares
about doing this only for the device where the debug is port actually
in use, i.e. it needs to be told the coordinates of the device being
reset (quite obviously, leveraging the addition done for that would
likely benefit the in-tree driver too).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 23 insertions, 6 deletions

diff --git a/include/linux/usb/ehci_def.h b/include/linux/usb/ehci_def.h
index de4b9ed5d5dd..9a446302b658 100644
--- a/include/linux/usb/ehci_def.h
+++ b/include/linux/usb/ehci_def.h
@@ -221,18 +221,35 @@ extern int __init early_dbgp_init(char *s);
 extern struct console early_dbgp_console;
 #endif /* CONFIG_EARLY_PRINTK_DBGP */
 
+struct usb_hcd;
+
+#ifdef CONFIG_XEN_DOM0
+extern int xen_dbgp_reset_prep(struct usb_hcd *);
+extern int xen_dbgp_external_startup(struct usb_hcd *);
+#else
+static inline int xen_dbgp_reset_prep(struct usb_hcd *hcd)
+{
+	return 1; /* Shouldn't this be 0? */
+}
+
+static inline int xen_dbgp_external_startup(struct usb_hcd *hcd)
+{
+	return -1;
+}
+#endif
+
 #ifdef CONFIG_EARLY_PRINTK_DBGP
 /* Call backs from ehci host driver to ehci debug driver */
-extern int dbgp_external_startup(void);
-extern int dbgp_reset_prep(void);
+extern int dbgp_external_startup(struct usb_hcd *);
+extern int dbgp_reset_prep(struct usb_hcd *hcd);
 #else
-static inline int dbgp_reset_prep(void)
+static inline int dbgp_reset_prep(struct usb_hcd *hcd)
 {
-	return 1;
+	return xen_dbgp_reset_prep(hcd);
 }
-static inline int dbgp_external_startup(void)
+static inline int dbgp_external_startup(struct usb_hcd *hcd)
 {
-	return -1;
+	return xen_dbgp_external_startup(hcd);
 }
 #endif