Commit b85a2ebd authored by Wesley Cheng's avatar Wesley Cheng Committed by Greg Kroah-Hartman
Browse files

usb: host: xhci: Notify xHCI sideband on transfer ring free 



In the case of handling a USB bus reset, the xhci_discover_or_reset_device
can run without first notifying the xHCI sideband client driver to stop or
prevent the use of the transfer ring.  It was seen that when a bus reset
situation happened, the USB offload driver was attempting to fetch the xHCI
transfer ring information, which was already freed.

Tested-by: default avatarPuma Hsu <pumahsu@google.com>
Tested-by: default avatarDaehwan Jung <dh10.jung@samsung.com>
Signed-off-by: default avatarWesley Cheng <quic_wcheng@quicinc.com>
Acked-by: default avatarMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409194804.3773260-6-quic_wcheng@quicinc.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 000ab7da

drivers/usb/host/xhci-sideband.c

+28 −1
Original line number Diff line number Diff line
@@ -88,6 +88,30 @@ __xhci_sideband_remove_endpoint(struct xhci_sideband *sb, struct xhci_virt_ep *e 


/* sideband api functions */



/**

 * xhci_sideband_notify_ep_ring_free - notify client of xfer ring free

 * @sb: sideband instance for this usb device

 * @ep_index: usb endpoint index

 *

 * Notifies the xHCI sideband client driver of a xHCI transfer ring free

 * routine.  This will allow for the client to ensure that all transfers

 * are completed.

 *

 * The callback should be synchronous, as the ring free happens after.

 */

void xhci_sideband_notify_ep_ring_free(struct xhci_sideband *sb,

				       unsigned int ep_index)

{

	struct xhci_sideband_event evt;



	evt.type = XHCI_SIDEBAND_XFER_RING_FREE;

	evt.evt_data = &ep_index;



	if (sb->notify_client)

		sb->notify_client(sb->intf, &evt);

}

EXPORT_SYMBOL_GPL(xhci_sideband_notify_ep_ring_free);



/**

 * xhci_sideband_add_endpoint - add endpoint to sideband access list

 * @sb: sideband instance for this usb device
@@ -342,7 +366,9 @@ EXPORT_SYMBOL_GPL(xhci_sideband_interrupter_id); 
 * Return: pointer to a new xhci_sideband instance if successful. NULL otherwise.

 */

struct xhci_sideband *

xhci_sideband_register(struct usb_interface *intf, enum xhci_sideband_type type)

xhci_sideband_register(struct usb_interface *intf, enum xhci_sideband_type type,

		       int (*notify_client)(struct usb_interface *intf,

				    struct xhci_sideband_event *evt))

{

	struct usb_device *udev = interface_to_usbdev(intf);

	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
@@ -381,6 +407,7 @@ xhci_sideband_register(struct usb_interface *intf, enum xhci_sideband_type type) 
	sb->vdev = vdev;

	sb->intf = intf;

	sb->type = type;

	sb->notify_client = notify_client;

	vdev->sideband = sb;



	spin_unlock_irq(&xhci->lock);

drivers/usb/host/xhci.c

+3 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/string_choices.h>

#include <linux/dmi.h>

#include <linux/dma-mapping.h>

#include <linux/usb/xhci-sideband.h>



#include "xhci.h"

#include "xhci-trace.h"
@@ -3919,6 +3920,8 @@ static int xhci_discover_or_reset_device(struct usb_hcd *hcd, 
		}



		if (ep->ring) {

			if (ep->sideband)

				xhci_sideband_notify_ep_ring_free(ep->sideband, i);

			xhci_debugfs_remove_endpoint(xhci, virt_dev, i);

			xhci_free_endpoint_ring(xhci, virt_dev, i);

		}

include/linux/usb/xhci-sideband.h

+29 −1
Original line number Diff line number Diff line
@@ -21,6 +21,20 @@ enum xhci_sideband_type { 
	XHCI_SIDEBAND_VENDOR,

};



enum xhci_sideband_notify_type {

	XHCI_SIDEBAND_XFER_RING_FREE,

};



/**

 * struct xhci_sideband_event - sideband event

 * @type: notifier type

 * @evt_data: event data

 */

struct xhci_sideband_event {

	enum xhci_sideband_notify_type type;

	void *evt_data;

};



/**

 * struct xhci_sideband - representation of a sideband accessed usb device.

 * @xhci: The xhci host controller the usb device is connected to
@@ -30,6 +44,7 @@ enum xhci_sideband_type { 
 * @type: xHCI sideband type

 * @mutex: mutex for sideband operations

 * @intf: USB sideband client interface

 * @notify_client: callback for xHCI sideband sequences

 *

 * FIXME usb device accessed via sideband Keeping track of sideband accessed usb devices.

 */
@@ -44,10 +59,14 @@ struct xhci_sideband { 
	struct mutex			mutex;



	struct usb_interface		*intf;

	int (*notify_client)(struct usb_interface *intf,

			     struct xhci_sideband_event *evt);

};



struct xhci_sideband *

xhci_sideband_register(struct usb_interface *intf, enum xhci_sideband_type type);

xhci_sideband_register(struct usb_interface *intf, enum xhci_sideband_type type,

		       int (*notify_client)(struct usb_interface *intf,

				    struct xhci_sideband_event *evt));

void

xhci_sideband_unregister(struct xhci_sideband *sb);

int
@@ -71,4 +90,13 @@ void 
xhci_sideband_remove_interrupter(struct xhci_sideband *sb);

int

xhci_sideband_interrupter_id(struct xhci_sideband *sb);



#if IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND)

void xhci_sideband_notify_ep_ring_free(struct xhci_sideband *sb,

				       unsigned int ep_index);

#else

static inline void xhci_sideband_notify_ep_ring_free(struct xhci_sideband *sb,

						     unsigned int ep_index)

{ }

#endif /* IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND) */

#endif /* __LINUX_XHCI_SIDEBAND_H */