usb: Make core allocate resources per PCI-device.

Introduce the notion of a PCI device that may be associated with more than
one USB host controller driver (struct usb_hcd).  This patch is the start
of the work to separate the xHCI host controller into two roothubs: a USB
3.0 roothub with SuperSpeed-only ports, and a USB 2.0 roothub with
HS/FS/LS ports.

One usb_hcd structure is designated to be the "primary HCD", and a pointer
is added to the usb_hcd structure to keep track of that.  A new function
call, usb_hcd_is_primary_hcd() is added to check whether the USB hcd is
marked as the primary HCD (or if it is not part of a roothub pair).  To
allow the USB core and xHCI driver to access either roothub in a pair, a
"shared_hcd" pointer is added to the usb_hcd structure.

Add a new function, usb_create_shared_hcd(), that does roothub allocation
for paired roothubs.  It will act just like usb_create_hcd() did if the
primary_hcd pointer argument is NULL.  If it is passed a non-NULL
primary_hcd pointer, it sets usb_hcd->shared_hcd and usb_hcd->primary_hcd
fields.  It will also skip the bandwidth_mutex allocation, and set the
secondary hcd's bandwidth_mutex pointer to the primary HCD's mutex.

IRQs are only allocated once for the primary roothub.

Introduce a new usb_hcd driver flag that indicates the host controller
driver wants to create two roothubs.  If the HCD_SHARED flag is set, then
the USB core PCI probe methods will allocate a second roothub, and make
sure that second roothub gets freed during rmmod and in initialization
error paths.

When usb_hc_died() is called with the primary HCD, make sure that any
roothubs that share that host controller are also marked as being dead.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index b8bb6934f30b..0097136ba45d 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -147,6 +147,8 @@ struct usb_hcd {
          * to the device, or resetting the bandwidth after a failed attempt.
          */
         struct mutex            *bandwidth_mutex;
+        struct usb_hcd          *shared_hcd;
+        struct usb_hcd          *primary_hcd;
 
 
 #define HCD_BUFFER_POOLS        4
@@ -209,6 +211,7 @@ struct hc_driver {
         int     flags;
 #define HCD_MEMORY      0x0001          /* HC regs use memory (else I/O) */
 #define HCD_LOCAL_MEM   0x0002          /* HC needs local memory */
+#define HCD_SHARED      0x0004          /* Two (or more) usb_hcds share HW */
 #define HCD_USB11       0x0010          /* USB 1.1 */
 #define HCD_USB2        0x0020          /* USB 2.0 */
 #define HCD_USB3        0x0040          /* USB 3.0 */
@@ -370,8 +373,12 @@ extern int usb_hcd_get_frame_number(struct usb_device *udev);
 
 extern struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
                 struct device *dev, const char *bus_name);
+extern struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
+                struct device *dev, const char *bus_name,
+                struct usb_hcd *shared_hcd);
 extern struct usb_hcd *usb_get_hcd(struct usb_hcd *hcd);
 extern void usb_put_hcd(struct usb_hcd *hcd);
+extern int usb_hcd_is_primary_hcd(struct usb_hcd *hcd);
 extern int usb_add_hcd(struct usb_hcd *hcd,
                 unsigned int irqnum, unsigned long irqflags);
 extern void usb_remove_hcd(struct usb_hcd *hcd);