From c56354378426e550aaf6ddf3983f502a8fddeab5 Mon Sep 17 00:00:00 2001 From: Sarah Sharp Date: Thu, 28 Oct 2010 15:40:26 -0700 Subject: [PATCH] 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 --- drivers/usb/core/hcd.c | 108 +++++++++++++++++++++++++++++++++------- include/linux/usb/hcd.h | 7 +++ 2 files changed, 96 insertions(+), 19 deletions(-) diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index a0adcac3da08..ba15eeab824e 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -2143,7 +2143,9 @@ EXPORT_SYMBOL_GPL(usb_hcd_irq); * * This is called by bus glue to report a USB host controller that died * while operations may still have been pending. It's called automatically - * by the PCI glue, so only glue for non-PCI busses should need to call it. + * by the PCI glue, so only glue for non-PCI busses should need to call it. + * + * Only call this function with the primary HCD. */ void usb_hc_died (struct usb_hcd *hcd) { @@ -2162,17 +2164,31 @@ void usb_hc_died (struct usb_hcd *hcd) USB_STATE_NOTATTACHED); usb_kick_khubd (hcd->self.root_hub); } + if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) { + hcd = hcd->shared_hcd; + if (hcd->rh_registered) { + clear_bit(HCD_FLAG_POLL_RH, &hcd->flags); + + /* make khubd clean up old urbs and devices */ + usb_set_device_state(hcd->self.root_hub, + USB_STATE_NOTATTACHED); + usb_kick_khubd(hcd->self.root_hub); + } + } spin_unlock_irqrestore (&hcd_root_hub_lock, flags); + /* Make sure that the other roothub is also deallocated. */ } EXPORT_SYMBOL_GPL (usb_hc_died); /*-------------------------------------------------------------------------*/ /** - * usb_create_hcd - create and initialize an HCD structure + * usb_create_shared_hcd - create and initialize an HCD structure * @driver: HC driver that will use this hcd * @dev: device for this HC, stored in hcd->self.controller * @bus_name: value to store in hcd->self.bus_name + * @primary_hcd: a pointer to the usb_hcd structure that is sharing the + * PCI device. Only allocate certain resources for the primary HCD * Context: !in_interrupt() * * Allocate a struct usb_hcd, with extra space at the end for the @@ -2181,8 +2197,9 @@ EXPORT_SYMBOL_GPL (usb_hc_died); * * If memory is unavailable, returns NULL. */ -struct usb_hcd *usb_create_hcd (const struct hc_driver *driver, - struct device *dev, const char *bus_name) +struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver, + struct device *dev, const char *bus_name, + struct usb_hcd *primary_hcd) { struct usb_hcd *hcd; @@ -2191,16 +2208,24 @@ struct usb_hcd *usb_create_hcd (const struct hc_driver *driver, dev_dbg (dev, "hcd alloc failed\n"); return NULL; } - hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex), - GFP_KERNEL); - if (!hcd->bandwidth_mutex) { - kfree(hcd); - dev_dbg(dev, "hcd bandwidth mutex alloc failed\n"); - return NULL; + if (primary_hcd == NULL) { + hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex), + GFP_KERNEL); + if (!hcd->bandwidth_mutex) { + kfree(hcd); + dev_dbg(dev, "hcd bandwidth mutex alloc failed\n"); + return NULL; + } + mutex_init(hcd->bandwidth_mutex); + dev_set_drvdata(dev, hcd); + } else { + 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_init(hcd->bandwidth_mutex); - dev_set_drvdata(dev, hcd); kref_init(&hcd->kref); usb_bus_init(&hcd->self); @@ -2221,13 +2246,46 @@ struct usb_hcd *usb_create_hcd (const struct hc_driver *driver, "USB Host Controller"; return hcd; } +EXPORT_SYMBOL_GPL(usb_create_shared_hcd); + +/** + * usb_create_hcd - create and initialize an HCD structure + * @driver: HC driver that will use this hcd + * @dev: device for this HC, stored in hcd->self.controller + * @bus_name: value to store in hcd->self.bus_name + * Context: !in_interrupt() + * + * Allocate a struct usb_hcd, with extra space at the end for the + * HC driver's private data. Initialize the generic members of the + * hcd structure. + * + * If memory is unavailable, returns NULL. + */ +struct usb_hcd *usb_create_hcd(const struct hc_driver *driver, + struct device *dev, const char *bus_name) +{ + return usb_create_shared_hcd(driver, dev, bus_name, NULL); +} EXPORT_SYMBOL_GPL(usb_create_hcd); +/* + * Roothubs that share one PCI device must also share the bandwidth mutex. + * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is + * 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). + */ static void hcd_release (struct kref *kref) { struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref); - kfree(hcd->bandwidth_mutex); + if (usb_hcd_is_primary_hcd(hcd)) + kfree(hcd->bandwidth_mutex); + else + hcd->shared_hcd->shared_hcd = NULL; kfree(hcd); } @@ -2246,6 +2304,14 @@ void usb_put_hcd (struct usb_hcd *hcd) } EXPORT_SYMBOL_GPL(usb_put_hcd); +int usb_hcd_is_primary_hcd(struct usb_hcd *hcd) +{ + if (!hcd->primary_hcd) + return 1; + return hcd == hcd->primary_hcd; +} +EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd); + static int usb_hcd_request_irqs(struct usb_hcd *hcd, unsigned int irqnum, unsigned long irqflags) { @@ -2367,9 +2433,11 @@ int usb_add_hcd(struct usb_hcd *hcd, dev_dbg(hcd->self.controller, "supports USB remote wakeup\n"); /* enable irqs just before we start the controller */ - retval = usb_hcd_request_irqs(hcd, irqnum, irqflags); - if (retval) - goto err_request_irq; + if (usb_hcd_is_primary_hcd(hcd)) { + retval = usb_hcd_request_irqs(hcd, irqnum, irqflags); + if (retval) + goto err_request_irq; + } hcd->state = HC_STATE_RUNNING; retval = hcd->driver->start(hcd); @@ -2416,7 +2484,7 @@ err_register_root_hub: clear_bit(HCD_FLAG_POLL_RH, &hcd->flags); del_timer_sync(&hcd->rh_timer); err_hcd_driver_start: - if (hcd->irq >= 0) + if (usb_hcd_is_primary_hcd(hcd) && hcd->irq >= 0) free_irq(irqnum, hcd); err_request_irq: err_hcd_driver_setup: @@ -2480,8 +2548,10 @@ void usb_remove_hcd(struct usb_hcd *hcd) clear_bit(HCD_FLAG_POLL_RH, &hcd->flags); del_timer_sync(&hcd->rh_timer); - if (hcd->irq >= 0) - free_irq(hcd->irq, hcd); + if (usb_hcd_is_primary_hcd(hcd)) { + if (hcd->irq >= 0) + free_irq(hcd->irq, hcd); + } usb_put_dev(hcd->self.root_hub); usb_deregister_bus(&hcd->self); 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); -- 2.20.1