From d8521afe35862f4fbe3ccd6ca37897c0a304edf3 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 20 May 2014 18:08:28 -0700 Subject: [PATCH] usb: assign default peer ports for root hubs Assume that the peer of a superspeed port is the port with the same id on the shared_hcd root hub. This identification scheme is required of external hubs by the USB3 spec [1]. However, for root hubs, tier mismatch may be in effect [2]. Tier mismatch can only be enumerated via platform firmware. For now, simply perform the nominal association. A new lock 'usb_port_peer_mutex' is introduced to synchronize port device add/remove with peer lookups. It protects peering against changes to hcd->shared_hcd, hcd->self.root_hub, hdev->maxchild, and port_dev->child pointers. [1]: usb 3.1 section 10.3.3 [2]: xhci 1.1 appendix D Cc: Alan Stern [alan: usb_port_peer_mutex locking scheme] Acked-by: Alan Stern Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hcd.c | 43 +++++++++++++++++++----- drivers/usb/core/hub.c | 42 ++++++++++++++++-------- drivers/usb/core/hub.h | 2 ++ drivers/usb/core/port.c | 73 ++++++++++++++++++++++++++++++++++++++--- drivers/usb/core/usb.h | 1 + 5 files changed, 134 insertions(+), 27 deletions(-) diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 174eb857a6b..b81407518fd 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -2458,11 +2458,13 @@ struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver, mutex_init(hcd->bandwidth_mutex); dev_set_drvdata(dev, hcd); } else { + mutex_lock(&usb_port_peer_mutex); hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex; hcd->primary_hcd = primary_hcd; primary_hcd->primary_hcd = primary_hcd; hcd->shared_hcd = primary_hcd; primary_hcd->shared_hcd = hcd; + mutex_unlock(&usb_port_peer_mutex); } kref_init(&hcd->kref); @@ -2514,18 +2516,25 @@ EXPORT_SYMBOL_GPL(usb_create_hcd); * deallocated. * * Make sure to only deallocate the bandwidth_mutex when the primary HCD is - * freed. When hcd_release() is called for the non-primary HCD, set the - * primary_hcd's shared_hcd pointer to null (since the non-primary HCD will be - * freed shortly). + * freed. When hcd_release() is called for either hcd in a peer set + * invalidate the peer's ->shared_hcd and ->primary_hcd pointers to + * block new peering attempts */ -static void hcd_release (struct kref *kref) +static void hcd_release(struct kref *kref) { struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref); + mutex_lock(&usb_port_peer_mutex); if (usb_hcd_is_primary_hcd(hcd)) kfree(hcd->bandwidth_mutex); - else - hcd->shared_hcd->shared_hcd = NULL; + if (hcd->shared_hcd) { + struct usb_hcd *peer = hcd->shared_hcd; + + peer->shared_hcd = NULL; + if (peer->primary_hcd == hcd) + peer->primary_hcd = NULL; + } + mutex_unlock(&usb_port_peer_mutex); kfree(hcd); } @@ -2593,6 +2602,21 @@ static int usb_hcd_request_irqs(struct usb_hcd *hcd, return 0; } +/* + * Before we free this root hub, flush in-flight peering attempts + * and disable peer lookups + */ +static void usb_put_invalidate_rhdev(struct usb_hcd *hcd) +{ + struct usb_device *rhdev; + + mutex_lock(&usb_port_peer_mutex); + rhdev = hcd->self.root_hub; + hcd->self.root_hub = NULL; + mutex_unlock(&usb_port_peer_mutex); + usb_put_dev(rhdev); +} + /** * usb_add_hcd - finish generic HCD structure initialization and register * @hcd: the usb_hcd structure to initialize @@ -2653,7 +2677,9 @@ int usb_add_hcd(struct usb_hcd *hcd, retval = -ENOMEM; goto err_allocate_root_hub; } + mutex_lock(&usb_port_peer_mutex); hcd->self.root_hub = rhdev; + mutex_unlock(&usb_port_peer_mutex); switch (hcd->speed) { case HCD_USB11: @@ -2762,7 +2788,7 @@ err_hcd_driver_start: err_request_irq: err_hcd_driver_setup: err_set_rh_speed: - usb_put_dev(hcd->self.root_hub); + usb_put_invalidate_rhdev(hcd); err_allocate_root_hub: usb_deregister_bus(&hcd->self); err_register_bus: @@ -2842,7 +2868,6 @@ void usb_remove_hcd(struct usb_hcd *hcd) free_irq(hcd->irq, hcd); } - usb_put_dev(hcd->self.root_hub); usb_deregister_bus(&hcd->self); hcd_buffer_destroy(hcd); if (hcd->remove_phy && hcd->phy) { @@ -2850,6 +2875,8 @@ void usb_remove_hcd(struct usb_hcd *hcd) usb_put_phy(hcd->phy); hcd->phy = NULL; } + + usb_put_invalidate_rhdev(hcd); } EXPORT_SYMBOL_GPL(usb_remove_hcd); diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 29129250877..5a909ba6fb6 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -55,6 +55,9 @@ static DECLARE_WAIT_QUEUE_HEAD(khubd_wait); static struct task_struct *khubd_task; +/* synchronize hub-port add/remove and peering operations */ +DEFINE_MUTEX(usb_port_peer_mutex); + /* cycle leds on hubs that aren't blinking for attention */ static bool blinkenlights = 0; module_param (blinkenlights, bool, S_IRUGO); @@ -1323,6 +1326,7 @@ static int hub_configure(struct usb_hub *hub, char *message = "out of memory"; unsigned unit_load; unsigned full_load; + unsigned maxchild; hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL); if (!hub->buffer) { @@ -1361,12 +1365,11 @@ static int hub_configure(struct usb_hub *hub, goto fail; } - hdev->maxchild = hub->descriptor->bNbrPorts; - dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild, - (hdev->maxchild == 1) ? "" : "s"); + maxchild = hub->descriptor->bNbrPorts; + dev_info(hub_dev, "%d port%s detected\n", maxchild, + (maxchild == 1) ? "" : "s"); - hub->ports = kzalloc(hdev->maxchild * sizeof(struct usb_port *), - GFP_KERNEL); + hub->ports = kzalloc(maxchild * sizeof(struct usb_port *), GFP_KERNEL); if (!hub->ports) { ret = -ENOMEM; goto fail; @@ -1387,11 +1390,11 @@ static int hub_configure(struct usb_hub *hub, int i; char portstr[USB_MAXCHILDREN + 1]; - for (i = 0; i < hdev->maxchild; i++) + for (i = 0; i < maxchild; i++) portstr[i] = hub->descriptor->u.hs.DeviceRemovable [((i + 1) / 8)] & (1 << ((i + 1) % 8)) ? 'F' : 'R'; - portstr[hdev->maxchild] = 0; + portstr[maxchild] = 0; dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr); } else dev_dbg(hub_dev, "standalone hub\n"); @@ -1503,7 +1506,7 @@ static int hub_configure(struct usb_hub *hub, if (hcd->power_budget > 0) hdev->bus_mA = hcd->power_budget; else - hdev->bus_mA = full_load * hdev->maxchild; + hdev->bus_mA = full_load * maxchild; if (hdev->bus_mA >= full_load) hub->mA_per_port = full_load; else { @@ -1518,7 +1521,7 @@ static int hub_configure(struct usb_hub *hub, hub->descriptor->bHubContrCurrent); hub->limited_power = 1; - if (remaining < hdev->maxchild * unit_load) + if (remaining < maxchild * unit_load) dev_warn(hub_dev, "insufficient power available " "to use all downstream ports\n"); @@ -1586,15 +1589,19 @@ static int hub_configure(struct usb_hub *hub, if (hub->has_indicators && blinkenlights) hub->indicator[0] = INDICATOR_CYCLE; - for (i = 0; i < hdev->maxchild; i++) { + mutex_lock(&usb_port_peer_mutex); + for (i = 0; i < maxchild; i++) { ret = usb_hub_create_port_device(hub, i + 1); if (ret < 0) { dev_err(hub->intfdev, "couldn't create port%d device.\n", i + 1); - hdev->maxchild = i; - goto fail_keep_maxchild; + break; } } + hdev->maxchild = i; + mutex_unlock(&usb_port_peer_mutex); + if (ret < 0) + goto fail; usb_hub_adjust_deviceremovable(hdev, hub->descriptor); @@ -1602,8 +1609,6 @@ static int hub_configure(struct usb_hub *hub, return 0; fail: - hdev->maxchild = 0; -fail_keep_maxchild: dev_err (hub_dev, "config failed, %s (err %d)\n", message, ret); /* hub_disconnect() frees urb and descriptor */ @@ -1639,6 +1644,8 @@ static void hub_disconnect(struct usb_interface *intf) hub->error = 0; hub_quiesce(hub, HUB_DISCONNECT); + mutex_lock(&usb_port_peer_mutex); + /* Avoid races with recursively_mark_NOTATTACHED() */ spin_lock_irq(&device_state_lock); port1 = hdev->maxchild; @@ -1649,6 +1656,8 @@ static void hub_disconnect(struct usb_interface *intf) for (; port1 > 0; --port1) usb_hub_remove_port_device(hub, port1); + mutex_unlock(&usb_port_peer_mutex); + if (hub->hdev->speed == USB_SPEED_HIGH) highspeed_hubs--; @@ -4608,6 +4617,8 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1, */ status = 0; + mutex_lock(&usb_port_peer_mutex); + /* We mustn't add new devices if the parent hub has * been disconnected; we would race with the * recursively_mark_NOTATTACHED() routine. @@ -4618,14 +4629,17 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1, else port_dev->child = udev; spin_unlock_irq(&device_state_lock); + mutex_unlock(&usb_port_peer_mutex); /* Run it through the hoops (find a driver, etc) */ if (!status) { status = usb_new_device(udev); if (status) { + mutex_lock(&usb_port_peer_mutex); spin_lock_irq(&device_state_lock); port_dev->child = NULL; spin_unlock_irq(&device_state_lock); + mutex_unlock(&usb_port_peer_mutex); } } diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h index 4bd72dd303d..fcad5f9d12f 100644 --- a/drivers/usb/core/hub.h +++ b/drivers/usb/core/hub.h @@ -82,6 +82,7 @@ struct usb_hub { * @child: usb device attached to the port * @dev: generic device interface * @port_owner: port's owner + * @peer: related usb2 and usb3 ports (share the same connector) * @connect_type: port's connect type * @portnum: port index num based one * @power_is_on: port's power state @@ -91,6 +92,7 @@ struct usb_port { struct usb_device *child; struct device dev; struct usb_dev_state *port_owner; + struct usb_port *peer; enum usb_port_connect_type connect_type; u8 portnum; unsigned power_is_on:1; diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c index 6a8999728cb..5ecdbf31dfc 100644 --- a/drivers/usb/core/port.c +++ b/drivers/usb/core/port.c @@ -157,9 +157,66 @@ static struct device_driver usb_port_driver = { .owner = THIS_MODULE, }; +static void link_peers(struct usb_port *left, struct usb_port *right) +{ + if (left->peer == right && right->peer == left) + return; + + if (left->peer || right->peer) { + struct usb_port *lpeer = left->peer; + struct usb_port *rpeer = right->peer; + + WARN(1, "failed to peer %s and %s (%s -> %p) (%s -> %p)\n", + dev_name(&left->dev), dev_name(&right->dev), + dev_name(&left->dev), lpeer, + dev_name(&right->dev), rpeer); + return; + } + + left->peer = right; + right->peer = left; +} + +static void unlink_peers(struct usb_port *left, struct usb_port *right) +{ + WARN(right->peer != left || left->peer != right, + "%s and %s are not peers?\n", + dev_name(&left->dev), dev_name(&right->dev)); + + right->peer = NULL; + left->peer = NULL; +} + +/* set the default peer port for root hubs */ +static void find_and_link_peer(struct usb_hub *hub, int port1) +{ + struct usb_port *port_dev = hub->ports[port1 - 1], *peer; + struct usb_device *hdev = hub->hdev; + + if (!hdev->parent) { + struct usb_hub *peer_hub; + struct usb_device *peer_hdev; + struct usb_hcd *hcd = bus_to_hcd(hdev->bus); + struct usb_hcd *peer_hcd = hcd->shared_hcd; + + if (!peer_hcd) + return; + + peer_hdev = peer_hcd->self.root_hub; + peer_hub = usb_hub_to_struct_hub(peer_hdev); + if (!peer_hub || port1 > peer_hdev->maxchild) + return; + + peer = peer_hub->ports[port1 - 1]; + + if (peer) + link_peers(port_dev, peer); + } +} + int usb_hub_create_port_device(struct usb_hub *hub, int port1) { - struct usb_port *port_dev = NULL; + struct usb_port *port_dev; int retval; port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL); @@ -181,6 +238,8 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1) if (retval) goto error_register; + find_and_link_peer(hub, port1); + pm_runtime_set_active(&port_dev->dev); /* @@ -203,9 +262,13 @@ exit: return retval; } -void usb_hub_remove_port_device(struct usb_hub *hub, - int port1) +void usb_hub_remove_port_device(struct usb_hub *hub, int port1) { - device_unregister(&hub->ports[port1 - 1]->dev); -} + struct usb_port *port_dev = hub->ports[port1 - 1]; + struct usb_port *peer; + peer = port_dev->peer; + if (peer) + unlink_peers(port_dev, peer); + device_unregister(&port_dev->dev); +} diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h index 69bfc253a7b..6afa738b5ba 100644 --- a/drivers/usb/core/usb.h +++ b/drivers/usb/core/usb.h @@ -119,6 +119,7 @@ static inline int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable) #endif extern struct bus_type usb_bus_type; +extern struct mutex usb_port_peer_mutex; extern struct device_type usb_device_type; extern struct device_type usb_if_device_type; extern struct device_type usb_ep_device_type; -- 2.46.0