/* * drivers/usb/core/usb.c * * (C) Copyright Linus Torvalds 1999 * (C) Copyright Johannes Erdfelt 1999-2001 * (C) Copyright Andreas Gal 1999 * (C) Copyright Gregory P. Smith 1999 * (C) Copyright Deti Fliegl 1999 (new USB architecture) * (C) Copyright Randy Dunlap 2000 * (C) Copyright David Brownell 2000-2004 * (C) Copyright Yggdrasil Computing, Inc. 2000 * (usb_device_id matching changes by Adam J. Richter) * (C) Copyright Greg Kroah-Hartman 2002-2003 * * NOTE! This is not actually a driver at all, rather this is * just a collection of helper routines that implement the * generic USB things that the real drivers can use.. * * Think of this as a "USB library" rather than anything else. * It should be considered a slave, with no callbacks. Callbacks * are evil. */ #include #include #include #include #include #include /* for in_interrupt() */ #include #include #include #include #include #include #include #include #include #include #include #include "hcd.h" #include "usb.h" const char *usbcore_name = "usbcore"; static int nousb; /* Disable USB when built into kernel image */ /* Workqueue for autosuspend and for remote wakeup of root hubs */ struct workqueue_struct *ksuspend_usb_wq; #ifdef CONFIG_USB_SUSPEND static int usb_autosuspend_delay = 2; /* Default delay value, * in seconds */ module_param_named(autosuspend, usb_autosuspend_delay, int, 0644); MODULE_PARM_DESC(autosuspend, "default autosuspend delay"); #else #define usb_autosuspend_delay 0 #endif /** * usb_ifnum_to_if - get the interface object with a given interface number * @dev: the device whose current configuration is considered * @ifnum: the desired interface * * This walks the device descriptor for the currently active configuration * and returns a pointer to the interface with that particular interface * number, or null. * * Note that configuration descriptors are not required to assign interface * numbers sequentially, so that it would be incorrect to assume that * the first interface in that descriptor corresponds to interface zero. * This routine helps device drivers avoid such mistakes. * However, you should make sure that you do the right thing with any * alternate settings available for this interfaces. * * Don't call this function unless you are bound to one of the interfaces * on this device or you have locked the device! */ struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev, unsigned ifnum) { struct usb_host_config *config = dev->actconfig; int i; if (!config) return NULL; for (i = 0; i < config->desc.bNumInterfaces; i++) if (config->interface[i]->altsetting[0] .desc.bInterfaceNumber == ifnum) return config->interface[i]; return NULL; } EXPORT_SYMBOL_GPL(usb_ifnum_to_if); /** * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number. * @intf: the interface containing the altsetting in question * @altnum: the desired alternate setting number * * This searches the altsetting array of the specified interface for * an entry with the correct bAlternateSetting value and returns a pointer * to that entry, or null. * * Note that altsettings need not be stored sequentially by number, so * it would be incorrect to assume that the first altsetting entry in * the array corresponds to altsetting zero. This routine helps device * drivers avoid such mistakes. * * Don't call this function unless you are bound to the intf interface * or you have locked the device! */ struct usb_host_interface *usb_altnum_to_altsetting( const struct usb_interface *intf, unsigned int altnum) { int i; for (i = 0; i < intf->num_altsetting; i++) { if (intf->altsetting[i].desc.bAlternateSetting == altnum) return &intf->altsetting[i]; } return NULL; } EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting); struct find_interface_arg { int minor; struct usb_interface *interface; }; static int __find_interface(struct device *dev, void *data) { struct find_interface_arg *arg = data; struct usb_interface *intf; /* can't look at usb devices, only interfaces */ if (is_usb_device(dev)) return 0; intf = to_usb_interface(dev); if (intf->minor != -1 && intf->minor == arg->minor) { arg->interface = intf; return 1; } return 0; } /** * usb_find_interface - find usb_interface pointer for driver and device * @drv: the driver whose current configuration is considered * @minor: the minor number of the desired device * * This walks the driver device list and returns a pointer to the interface * with the matching minor. Note, this only works for devices that share the * USB major number. */ struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor) { struct find_interface_arg argb; int retval; argb.minor = minor; argb.interface = NULL; /* eat the error, it will be in argb.interface */ retval = driver_for_each_device(&drv->drvwrap.driver, NULL, &argb, __find_interface); return argb.interface; } EXPORT_SYMBOL_GPL(usb_find_interface); /** * usb_release_dev - free a usb device structure when all users of it are finished. * @dev: device that's been disconnected * * Will be called only by the device core when all users of this usb device are * done. */ static void usb_release_dev(struct device *dev) { struct usb_device *udev; udev = to_usb_device(dev); usb_destroy_configuration(udev); usb_put_hcd(bus_to_hcd(udev->bus)); kfree(udev->product); kfree(udev->manufacturer); kfree(udev->serial); kfree(udev); } #ifdef CONFIG_HOTPLUG static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env) { struct usb_device *usb_dev; usb_dev = to_usb_device(dev); if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum)) return -ENOMEM; if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum)) return -ENOMEM; return 0; } #else static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env) { return -ENODEV; } #endif /* CONFIG_HOTPLUG */ #ifdef CONFIG_PM static int ksuspend_usb_init(void) { /* This workqueue is supposed to be both freezable and * singlethreaded. Its job doesn't justify running on more * than one CPU. */ ksuspend_usb_wq = create_freezeable_workqueue("ksuspend_usbd"); if (!ksuspend_usb_wq) return -ENOMEM; return 0; } static void ksuspend_usb_cleanup(void) { destroy_workqueue(ksuspend_usb_wq); } /* USB device Power-Management thunks. * There's no need to distinguish here between quiescing a USB device * and powering it down; the generic_suspend() routine takes care of * it by skipping the usb_port_suspend() call for a quiesce. And for * USB interfaces there's no difference at all. */ static int usb_dev_prepare(struct device *dev) { return 0; /* Implement eventually? */ } static void usb_dev_complete(struct device *dev) { /* Currently used only for rebinding interfaces */ usb_resume(dev); /* Implement eventually? */ } static int usb_dev_suspend(struct device *dev) { return usb_suspend(dev, PMSG_SUSPEND); } static int usb_dev_resume(struct device *dev) { return usb_resume(dev); } static int usb_dev_freeze(struct device *dev) { return usb_suspend(dev, PMSG_FREEZE); } static int usb_dev_thaw(struct device *dev) { return usb_resume(dev); } static int usb_dev_poweroff(struct device *dev) { return usb_suspend(dev, PMSG_HIBERNATE); } static int usb_dev_restore(struct device *dev) { return usb_resume(dev); } static struct dev_pm_ops usb_device_pm_ops = { .prepare = usb_dev_prepare, .complete = usb_dev_complete, .suspend = usb_dev_suspend, .resume = usb_dev_resume, .freeze = usb_dev_freeze, .thaw = usb_dev_thaw, .poweroff = usb_dev_poweroff, .restore = usb_dev_restore, }; #else #define ksuspend_usb_init() 0 #define ksuspend_usb_cleanup() do {} while (0) #define usb_device_pm_ops (*(struct dev_pm_ops *)0) #endif /* CONFIG_PM */ struct device_type usb_device_type = { .name = "usb_device", .release = usb_release_dev, .uevent = usb_dev_uevent, .pm = &usb_device_pm_ops, }; /* Returns 1 if @usb_bus is WUSB, 0 otherwise */ static unsigned usb_bus_is_wusb(struct usb_bus *bus) { struct usb_hcd *hcd = container_of(bus, struct usb_hcd, self); return hcd->wireless; } /** * usb_alloc_dev - usb device constructor (usbcore-internal) * @parent: hub to which device is connected; null to allocate a root hub * @bus: bus used to access the device * @port1: one-based index of port; ignored for root hubs * Context: !in_interrupt() * * Only hub drivers (including virtual root hub drivers for host * controllers) should ever call this. * * This call may not be used in a non-sleeping context. */ struct usb_device *usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1) { struct usb_device *dev; struct usb_hcd *usb_hcd = container_of(bus, struct usb_hcd, self); unsigned root_hub = 0; dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (!dev) return NULL; if (!usb_get_hcd(bus_to_hcd(bus))) { kfree(dev); return NULL; } device_initialize(&dev->dev); dev->dev.bus = &usb_bus_type; dev->dev.type = &usb_device_type; dev->dev.groups = usb_device_groups; dev->dev.dma_mask = bus->controller->dma_mask; set_dev_node(&dev->dev, dev_to_node(bus->controller)); dev->state = USB_STATE_ATTACHED; atomic_set(&dev->urbnum, 0); INIT_LIST_HEAD(&dev->ep0.urb_list); dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE; dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT; /* ep0 maxpacket comes later, from device descriptor */ usb_enable_endpoint(dev, &dev->ep0); dev->can_submit = 1; /* Save readable and stable topology id, distinguishing devices * by location for diagnostics, tools, driver model, etc. The * string is a path along hub ports, from the root. Each device's * dev->devpath will be stable until USB is re-cabled, and hubs * are often labeled with these port numbers. The name isn't * as stable: bus->busnum changes easily from modprobe order, * cardbus or pci hotplugging, and so on. */ if (unlikely(!parent)) { dev->devpath[0] = '0'; dev->dev.parent = bus->controller; dev_set_name(&dev->dev, "usb%d", bus->busnum); root_hub = 1; } else { /* match any labeling on the hubs; it's one-based */ if (parent->devpath[0] == '0') snprintf(dev->devpath, sizeof dev->devpath, "%d", port1); else snprintf(dev->devpath, sizeof dev->devpath, "%s.%d", parent->devpath, port1); dev->dev.parent = &parent->dev; dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath); /* hub driver sets up TT records */ } dev->portnum = port1; dev->bus = bus; dev->parent = parent; INIT_LIST_HEAD(&dev->filelist); #ifdef CONFIG_PM mutex_init(&dev->pm_mutex); INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work); INIT_WORK(&dev->autoresume, usb_autoresume_work); dev->autosuspend_delay = usb_autosuspend_delay * HZ; dev->connect_time = jiffies; dev->active_duration = -jiffies; #endif if (root_hub) /* Root hub always ok [and always wired] */ dev->authorized = 1; else { dev->authorized = usb_hcd->authorized_default; dev->wusb = usb_bus_is_wusb(bus)? 1 : 0; } return dev; } /** * usb_get_dev - increments the reference count of the usb device structure * @dev: the device being referenced * * Each live reference to a device should be refcounted. * * Drivers for USB interfaces should normally record such references in * their probe() methods, when they bind to an interface, and release * them by calling usb_put_dev(), in their disconnect() methods. * * A pointer to the device with the incremented reference counter is returned. */ struct usb_device *usb_get_dev(struct usb_device *dev) { if (dev) get_device(&dev->dev); return dev; } EXPORT_SYMBOL_GPL(usb_get_dev); /** * usb_put_dev - release a use of the usb device structure * @dev: device that's been disconnected * * Must be called when a user of a device is finished with it. When the last * user of the device calls this function, the memory of the device is freed. */ void usb_put_dev(struct usb_device *dev) { if (dev) put_device(&dev->dev); } EXPORT_SYMBOL_GPL(usb_put_dev); /** * usb_get_intf - increments the reference count of the usb interface structure * @intf: the interface being referenced * * Each live reference to a interface must be refcounted. * * Drivers for USB interfaces should normally record such references in * their probe() methods, when they bind to an interface, and release * them by calling usb_put_intf(), in their disconnect() methods. * * A pointer to the interface with the incremented reference counter is * returned. */ struct usb_interface *usb_get_intf(struct usb_interface *intf) { if (intf) get_device(&intf->dev); return intf; } EXPORT_SYMBOL_GPL(usb_get_intf); /** * usb_put_intf - release a use of the usb interface structure * @intf: interface that's been decremented * * Must be called when a user of an interface is finished with it. When the * last user of the interface calls this function, the memory of the interface * is freed. */ void usb_put_intf(struct usb_interface *intf) { if (intf) put_device(&intf->dev); } EXPORT_SYMBOL_GPL(usb_put_intf); /* USB device locking * * USB devices and interfaces are locked using the semaphore in their * embedded struct device. The hub driver guarantees that whenever a * device is connected or disconnected, drivers are called with the * USB device locked as well as their particular interface. * * Complications arise when several devices are to be locked at the same * time. Only hub-aware drivers that are part of usbcore ever have to * do this; nobody else needs to worry about it. The rule for locking * is simple: * * When locking both a device and its parent, always lock the * the parent first. */ /** * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure * @udev: device that's being locked * @iface: interface bound to the driver making the request (optional) * * Attempts to acquire the device lock, but fails if the device is * NOTATTACHED or SUSPENDED, or if iface is specified and the interface * is neither BINDING nor BOUND. Rather than sleeping to wait for the * lock, the routine polls repeatedly. This is to prevent deadlock with * disconnect; in some drivers (such as usb-storage) the disconnect() * or suspend() method will block waiting for a device reset to complete. * * Returns a negative error code for failure, otherwise 0. */ int usb_lock_device_for_reset(struct usb_device *udev, const struct usb_interface *iface) { unsigned long jiffies_expire = jiffies + HZ; if (udev->state == USB_STATE_NOTATTACHED) return -ENODEV; if (udev->state == USB_STATE_SUSPENDED) return -EHOSTUNREACH; if (iface && (iface->condition == USB_INTERFACE_UNBINDING || iface->condition == USB_INTERFACE_UNBOUND)) return -EINTR; while (usb_trylock_device(udev) != 0) { /* If we can't acquire the lock after waiting one second, * we're probably deadlocked */ if (time_after(jiffies, jiffies_expire)) return -EBUSY; msleep(15); if (udev->state == USB_STATE_NOTATTACHED) return -ENODEV; if (udev->state == USB_STATE_SUSPENDED) return -EHOSTUNREACH; if (iface && (iface->condition == USB_INTERFACE_UNBINDING || iface->condition == USB_INTERFACE_UNBOUND)) return -EINTR; } return 0; } EXPORT_SYMBOL_GPL(usb_lock_device_for_reset); static struct usb_device *match_device(struct usb_device *dev, u16 vendor_id, u16 product_id) { struct usb_device *ret_dev = NULL; int child; dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n", le16_to_cpu(dev->descriptor.idVendor), le16_to_cpu(dev->descriptor.idProduct)); /* see if this device matches */ if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) && (product_id == le16_to_cpu(dev->descriptor.idProduct))) { dev_dbg(&dev->dev, "matched this device!\n"); ret_dev = usb_get_dev(dev); goto exit; } /* look through all of the children of this device */ for (child = 0; child < dev->maxchild; ++child) { if (dev->children[child]) { usb_lock_device(dev->children[child]); ret_dev = match_device(dev->children[child], vendor_id, product_id); usb_unlock_device(dev->children[child]); if (ret_dev) goto exit; } } exit: return ret_dev; } /** * usb_find_device - find a specific usb device in the system * @vendor_id: the vendor id of the device to find * @product_id: the product id of the device to find * * Returns a pointer to a struct usb_device if such a specified usb * device is present in the system currently. The usage count of the * device will be incremented if a device is found. Make sure to call * usb_put_dev() when the caller is finished with the device. * * If a device with the specified vendor and product id is not found, * NULL is returned. */ struct usb_device *usb_find_device(u16 vendor_id, u16 product_id) { struct list_head *buslist; struct usb_bus *bus; struct usb_device *dev = NULL; mutex_lock(&usb_bus_list_lock); for (buslist = usb_bus_list.next; buslist != &usb_bus_list; buslist = buslist->next) { bus = container_of(buslist, struct usb_bus, bus_list); if (!bus->root_hub) continue; usb_lock_device(bus->root_hub); dev = match_device(bus->root_hub, vendor_id, product_id); usb_unlock_device(bus->root_hub); if (dev) goto exit; } exit: mutex_unlock(&usb_bus_list_lock); return dev; } /** * usb_get_current_frame_number - return current bus frame number * @dev: the device whose bus is being queried * * Returns the current frame number for the USB host controller * used with the given USB device. This can be used when scheduling * isochronous requests. * * Note that different kinds of host controller have different * "scheduling horizons". While one type might support scheduling only * 32 frames into the future, others could support scheduling up to * 1024 frames into the future. */ int usb_get_current_frame_number(struct usb_device *dev) { return usb_hcd_get_frame_number(dev); } EXPORT_SYMBOL_GPL(usb_get_current_frame_number); /*-------------------------------------------------------------------*/ /* * __usb_get_extra_descriptor() finds a descriptor of specific type in the * extra field of the interface and endpoint descriptor structs. */ int __usb_get_extra_descriptor(char *buffer, unsigned size, unsigned char type, void **ptr) { struct usb_descriptor_header *header; while (size >= sizeof(struct usb_descriptor_header)) { header = (struct usb_descriptor_header *)buffer; if (header->bLength < 2) { printk(KERN_ERR "%s: bogus descriptor, type %d length %d\n", usbcore_name, header->bDescriptorType, header->bLength); return -1; } if (header->bDescriptorType == type) { *ptr = header; return 0; } buffer += header->bLength; size -= header->bLength; } return -1; } EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor); /** * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP * @dev: device the buffer will be used with * @size: requested buffer size * @mem_flags: affect whether allocation may block * @dma: used to return DMA address of buffer * * Return value is either null (indicating no buffer could be allocated), or * the cpu-space pointer to a buffer that may be used to perform DMA to the * specified device. Such cpu-space buffers are returned along with the DMA * address (through the pointer provided). * * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU * hardware during URB completion/resubmit. The implementation varies between * platforms, depending on details of how DMA will work to this device. * Using these buffers also eliminates cacheline sharing problems on * architectures where CPU caches are not DMA-coherent. On systems without * bus-snooping caches, these buffers are uncached. * * When the buffer is no longer used, free it with usb_buffer_free(). */ void *usb_buffer_alloc(struct usb_device *dev, size_t size, gfp_t mem_flags, dma_addr_t *dma) { if (!dev || !dev->bus) return NULL; return hcd_buffer_alloc(dev->bus, size, mem_flags, dma); } EXPORT_SYMBOL_GPL(usb_buffer_alloc); /** * usb_buffer_free - free memory allocated with usb_buffer_alloc() * @dev: device the buffer was used with * @size: requested buffer size * @addr: CPU address of buffer * @dma: DMA address of buffer * * This reclaims an I/O buffer, letting it be reused. The memory must have * been allocated using usb_buffer_alloc(), and the parameters must match * those provided in that allocation request. */ void usb_buffer_free(struct usb_device *dev, size_t size, void *addr, dma_addr_t dma) { if (!dev || !dev->bus) return; if (!addr) return; hcd_buffer_free(dev->bus, size, addr, dma); } EXPORT_SYMBOL_GPL(usb_buffer_free); /** * usb_buffer_map - create DMA mapping(s) for an urb * @urb: urb whose transfer_buffer/setup_packet will be mapped * * Return value is either null (indicating no buffer could be mapped), or * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are * added to urb->transfer_flags if the operation succeeds. If the device * is connected to this system through a non-DMA controller, this operation * always succeeds. * * This call would normally be used for an urb which is reused, perhaps * as the target of a large periodic transfer, with usb_buffer_dmasync() * calls to synchronize memory and dma state. * * Reverse the effect of this call with usb_buffer_unmap(). */ #if 0 struct urb *usb_buffer_map(struct urb *urb) { struct usb_bus *bus; struct device *controller; if (!urb || !urb->dev || !(bus = urb->dev->bus) || !(controller = bus->controller)) return NULL; if (controller->dma_mask) { urb->transfer_dma = dma_map_single(controller, urb->transfer_buffer, urb->transfer_buffer_length, usb_pipein(urb->pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); if (usb_pipecontrol(urb->pipe)) urb->setup_dma = dma_map_single(controller, urb->setup_packet, sizeof(struct usb_ctrlrequest), DMA_TO_DEVICE); /* FIXME generic api broken like pci, can't report errors */ /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */ } else urb->transfer_dma = ~0; urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP | URB_NO_SETUP_DMA_MAP); return urb; } EXPORT_SYMBOL_GPL(usb_buffer_map); #endif /* 0 */ /* XXX DISABLED, no users currently. If you wish to re-enable this * XXX please determine whether the sync is to transfer ownership of * XXX the buffer from device to cpu or vice verse, and thusly use the * XXX appropriate _for_{cpu,device}() method. -DaveM */ #if 0 /** * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s) * @urb: urb whose transfer_buffer/setup_packet will be synchronized */ void usb_buffer_dmasync(struct urb *urb) { struct usb_bus *bus; struct device *controller; if (!urb || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) || !urb->dev || !(bus = urb->dev->bus) || !(controller = bus->controller)) return; if (controller->dma_mask) { dma_sync_single(controller, urb->transfer_dma, urb->transfer_buffer_length, usb_pipein(urb->pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); if (usb_pipecontrol(urb->pipe)) dma_sync_single(controller, urb->setup_dma, sizeof(struct usb_ctrlrequest), DMA_TO_DEVICE); } } EXPORT_SYMBOL_GPL(usb_buffer_dmasync); #endif /** * usb_buffer_unmap - free DMA mapping(s) for an urb * @urb: urb whose transfer_buffer will be unmapped * * Reverses the effect of usb_buffer_map(). */ #if 0 void usb_buffer_unmap(struct urb *urb) { struct usb_bus *bus; struct device *controller; if (!urb || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) || !urb->dev || !(bus = urb->dev->bus) || !(controller = bus->controller)) return; if (controller->dma_mask) { dma_unmap_single(controller, urb->transfer_dma, urb->transfer_buffer_length, usb_pipein(urb->pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); if (usb_pipecontrol(urb->pipe)) dma_unmap_single(controller, urb->setup_dma, sizeof(struct usb_ctrlrequest), DMA_TO_DEVICE); } urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP | URB_NO_SETUP_DMA_MAP); } EXPORT_SYMBOL_GPL(usb_buffer_unmap); #endif /* 0 */ /** * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint * @dev: device to which the scatterlist will be mapped * @is_in: mapping transfer direction * @sg: the scatterlist to map * @nents: the number of entries in the scatterlist * * Return value is either < 0 (indicating no buffers could be mapped), or * the number of DMA mapping array entries in the scatterlist. * * The caller is responsible for placing the resulting DMA addresses from * the scatterlist into URB transfer buffer pointers, and for setting the * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs. * * Top I/O rates come from queuing URBs, instead of waiting for each one * to complete before starting the next I/O. This is particularly easy * to do with scatterlists. Just allocate and submit one URB for each DMA * mapping entry returned, stopping on the first error or when all succeed. * Better yet, use the usb_sg_*() calls, which do that (and more) for you. * * This call would normally be used when translating scatterlist requests, * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it * may be able to coalesce mappings for improved I/O efficiency. * * Reverse the effect of this call with usb_buffer_unmap_sg(). */ int usb_buffer_map_sg(const struct usb_device *dev, int is_in, struct scatterlist *sg, int nents) { struct usb_bus *bus; struct device *controller; if (!dev || !(bus = dev->bus) || !(controller = bus->controller) || !controller->dma_mask) return -1; /* FIXME generic api broken like pci, can't report errors */ return dma_map_sg(controller, sg, nents, is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } EXPORT_SYMBOL_GPL(usb_buffer_map_sg); /* XXX DISABLED, no users currently. If you wish to re-enable this * XXX please determine whether the sync is to transfer ownership of * XXX the buffer from device to cpu or vice verse, and thusly use the * XXX appropriate _for_{cpu,device}() method. -DaveM */ #if 0 /** * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s) * @dev: device to which the scatterlist will be mapped * @is_in: mapping transfer direction * @sg: the scatterlist to synchronize * @n_hw_ents: the positive return value from usb_buffer_map_sg * * Use this when you are re-using a scatterlist's data buffers for * another USB request. */ void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in, struct scatterlist *sg, int n_hw_ents) { struct usb_bus *bus; struct device *controller; if (!dev || !(bus = dev->bus) || !(controller = bus->controller) || !controller->dma_mask) return; dma_sync_sg(controller, sg, n_hw_ents, is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg); #endif /** * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist * @dev: device to which the scatterlist will be mapped * @is_in: mapping transfer direction * @sg: the scatterlist to unmap * @n_hw_ents: the positive return value from usb_buffer_map_sg * * Reverses the effect of usb_buffer_map_sg(). */ void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in, struct scatterlist *sg, int n_hw_ents) { struct usb_bus *bus; struct device *controller; if (!dev || !(bus = dev->bus) || !(controller = bus->controller) || !controller->dma_mask) return; dma_unmap_sg(controller, sg, n_hw_ents, is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg); /* format to disable USB on kernel command line is: nousb */ __module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444); /* * for external read access to */ int usb_disabled(void) { return nousb; } EXPORT_SYMBOL_GPL(usb_disabled); /* * Init */ static int __init usb_init(void) { int retval; if (nousb) { pr_info("%s: USB support disabled\n", usbcore_name); return 0; } retval = ksuspend_usb_init(); if (retval) goto out; retval = bus_register(&usb_bus_type); if (retval) goto bus_register_failed; retval = usb_host_init(); if (retval) goto host_init_failed; retval = usb_major_init(); if (retval) goto major_init_failed; retval = usb_register(&usbfs_driver); if (retval) goto driver_register_failed; retval = usb_devio_init(); if (retval) goto usb_devio_init_failed; retval = usbfs_init(); if (retval) goto fs_init_failed; retval = usb_hub_init(); if (retval) goto hub_init_failed; retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE); if (!retval) goto out; usb_hub_cleanup(); hub_init_failed: usbfs_cleanup(); fs_init_failed: usb_devio_cleanup(); usb_devio_init_failed: usb_deregister(&usbfs_driver); driver_register_failed: usb_major_cleanup(); major_init_failed: usb_host_cleanup(); host_init_failed: bus_unregister(&usb_bus_type); bus_register_failed: ksuspend_usb_cleanup(); out: return retval; } /* * Cleanup */ static void __exit usb_exit(void) { /* This will matter if shutdown/reboot does exitcalls. */ if (nousb) return; usb_deregister_device_driver(&usb_generic_driver); usb_major_cleanup(); usbfs_cleanup(); usb_deregister(&usbfs_driver); usb_devio_cleanup(); usb_hub_cleanup(); usb_host_cleanup(); bus_unregister(&usb_bus_type); ksuspend_usb_cleanup(); } subsys_initcall(usb_init); module_exit(usb_exit); MODULE_LICENSE("GPL");