Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
new file mode 100644
index 0000000..dc838f8
--- /dev/null
+++ b/drivers/usb/core/urb.c
@@ -0,0 +1,511 @@
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/bitops.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+
+#ifdef CONFIG_USB_DEBUG
+ #define DEBUG
+#else
+ #undef DEBUG
+#endif
+#include <linux/usb.h>
+#include "hcd.h"
+
+#define to_urb(d) container_of(d, struct urb, kref)
+
+static void urb_destroy(struct kref *kref)
+{
+ struct urb *urb = to_urb(kref);
+ kfree(urb);
+}
+
+/**
+ * usb_init_urb - initializes a urb so that it can be used by a USB driver
+ * @urb: pointer to the urb to initialize
+ *
+ * Initializes a urb so that the USB subsystem can use it properly.
+ *
+ * If a urb is created with a call to usb_alloc_urb() it is not
+ * necessary to call this function. Only use this if you allocate the
+ * space for a struct urb on your own. If you call this function, be
+ * careful when freeing the memory for your urb that it is no longer in
+ * use by the USB core.
+ *
+ * Only use this function if you _really_ understand what you are doing.
+ */
+void usb_init_urb(struct urb *urb)
+{
+ if (urb) {
+ memset(urb, 0, sizeof(*urb));
+ kref_init(&urb->kref);
+ spin_lock_init(&urb->lock);
+ }
+}
+
+/**
+ * usb_alloc_urb - creates a new urb for a USB driver to use
+ * @iso_packets: number of iso packets for this urb
+ * @mem_flags: the type of memory to allocate, see kmalloc() for a list of
+ * valid options for this.
+ *
+ * Creates an urb for the USB driver to use, initializes a few internal
+ * structures, incrementes the usage counter, and returns a pointer to it.
+ *
+ * If no memory is available, NULL is returned.
+ *
+ * If the driver want to use this urb for interrupt, control, or bulk
+ * endpoints, pass '0' as the number of iso packets.
+ *
+ * The driver must call usb_free_urb() when it is finished with the urb.
+ */
+struct urb *usb_alloc_urb(int iso_packets, int mem_flags)
+{
+ struct urb *urb;
+
+ urb = (struct urb *)kmalloc(sizeof(struct urb) +
+ iso_packets * sizeof(struct usb_iso_packet_descriptor),
+ mem_flags);
+ if (!urb) {
+ err("alloc_urb: kmalloc failed");
+ return NULL;
+ }
+ usb_init_urb(urb);
+ return urb;
+}
+
+/**
+ * usb_free_urb - frees the memory used by a urb when all users of it are finished
+ * @urb: pointer to the urb to free, may be NULL
+ *
+ * Must be called when a user of a urb is finished with it. When the last user
+ * of the urb calls this function, the memory of the urb is freed.
+ *
+ * Note: The transfer buffer associated with the urb is not freed, that must be
+ * done elsewhere.
+ */
+void usb_free_urb(struct urb *urb)
+{
+ if (urb)
+ kref_put(&urb->kref, urb_destroy);
+}
+
+/**
+ * usb_get_urb - increments the reference count of the urb
+ * @urb: pointer to the urb to modify, may be NULL
+ *
+ * This must be called whenever a urb is transferred from a device driver to a
+ * host controller driver. This allows proper reference counting to happen
+ * for urbs.
+ *
+ * A pointer to the urb with the incremented reference counter is returned.
+ */
+struct urb * usb_get_urb(struct urb *urb)
+{
+ if (urb)
+ kref_get(&urb->kref);
+ return urb;
+}
+
+
+/*-------------------------------------------------------------------*/
+
+/**
+ * usb_submit_urb - issue an asynchronous transfer request for an endpoint
+ * @urb: pointer to the urb describing the request
+ * @mem_flags: the type of memory to allocate, see kmalloc() for a list
+ * of valid options for this.
+ *
+ * This submits a transfer request, and transfers control of the URB
+ * describing that request to the USB subsystem. Request completion will
+ * be indicated later, asynchronously, by calling the completion handler.
+ * The three types of completion are success, error, and unlink
+ * (a software-induced fault, also called "request cancelation").
+ *
+ * URBs may be submitted in interrupt context.
+ *
+ * The caller must have correctly initialized the URB before submitting
+ * it. Functions such as usb_fill_bulk_urb() and usb_fill_control_urb() are
+ * available to ensure that most fields are correctly initialized, for
+ * the particular kind of transfer, although they will not initialize
+ * any transfer flags.
+ *
+ * Successful submissions return 0; otherwise this routine returns a
+ * negative error number. If the submission is successful, the complete()
+ * callback from the URB will be called exactly once, when the USB core and
+ * Host Controller Driver (HCD) are finished with the URB. When the completion
+ * function is called, control of the URB is returned to the device
+ * driver which issued the request. The completion handler may then
+ * immediately free or reuse that URB.
+ *
+ * With few exceptions, USB device drivers should never access URB fields
+ * provided by usbcore or the HCD until its complete() is called.
+ * The exceptions relate to periodic transfer scheduling. For both
+ * interrupt and isochronous urbs, as part of successful URB submission
+ * urb->interval is modified to reflect the actual transfer period used
+ * (normally some power of two units). And for isochronous urbs,
+ * urb->start_frame is modified to reflect when the URB's transfers were
+ * scheduled to start. Not all isochronous transfer scheduling policies
+ * will work, but most host controller drivers should easily handle ISO
+ * queues going from now until 10-200 msec into the future.
+ *
+ * For control endpoints, the synchronous usb_control_msg() call is
+ * often used (in non-interrupt context) instead of this call.
+ * That is often used through convenience wrappers, for the requests
+ * that are standardized in the USB 2.0 specification. For bulk
+ * endpoints, a synchronous usb_bulk_msg() call is available.
+ *
+ * Request Queuing:
+ *
+ * URBs may be submitted to endpoints before previous ones complete, to
+ * minimize the impact of interrupt latencies and system overhead on data
+ * throughput. With that queuing policy, an endpoint's queue would never
+ * be empty. This is required for continuous isochronous data streams,
+ * and may also be required for some kinds of interrupt transfers. Such
+ * queuing also maximizes bandwidth utilization by letting USB controllers
+ * start work on later requests before driver software has finished the
+ * completion processing for earlier (successful) requests.
+ *
+ * As of Linux 2.6, all USB endpoint transfer queues support depths greater
+ * than one. This was previously a HCD-specific behavior, except for ISO
+ * transfers. Non-isochronous endpoint queues are inactive during cleanup
+ * after faults (transfer errors or cancelation).
+ *
+ * Reserved Bandwidth Transfers:
+ *
+ * Periodic transfers (interrupt or isochronous) are performed repeatedly,
+ * using the interval specified in the urb. Submitting the first urb to
+ * the endpoint reserves the bandwidth necessary to make those transfers.
+ * If the USB subsystem can't allocate sufficient bandwidth to perform
+ * the periodic request, submitting such a periodic request should fail.
+ *
+ * Device drivers must explicitly request that repetition, by ensuring that
+ * some URB is always on the endpoint's queue (except possibly for short
+ * periods during completion callacks). When there is no longer an urb
+ * queued, the endpoint's bandwidth reservation is canceled. This means
+ * drivers can use their completion handlers to ensure they keep bandwidth
+ * they need, by reinitializing and resubmitting the just-completed urb
+ * until the driver longer needs that periodic bandwidth.
+ *
+ * Memory Flags:
+ *
+ * The general rules for how to decide which mem_flags to use
+ * are the same as for kmalloc. There are four
+ * different possible values; GFP_KERNEL, GFP_NOFS, GFP_NOIO and
+ * GFP_ATOMIC.
+ *
+ * GFP_NOFS is not ever used, as it has not been implemented yet.
+ *
+ * GFP_ATOMIC is used when
+ * (a) you are inside a completion handler, an interrupt, bottom half,
+ * tasklet or timer, or
+ * (b) you are holding a spinlock or rwlock (does not apply to
+ * semaphores), or
+ * (c) current->state != TASK_RUNNING, this is the case only after
+ * you've changed it.
+ *
+ * GFP_NOIO is used in the block io path and error handling of storage
+ * devices.
+ *
+ * All other situations use GFP_KERNEL.
+ *
+ * Some more specific rules for mem_flags can be inferred, such as
+ * (1) start_xmit, timeout, and receive methods of network drivers must
+ * use GFP_ATOMIC (they are called with a spinlock held);
+ * (2) queuecommand methods of scsi drivers must use GFP_ATOMIC (also
+ * called with a spinlock held);
+ * (3) If you use a kernel thread with a network driver you must use
+ * GFP_NOIO, unless (b) or (c) apply;
+ * (4) after you have done a down() you can use GFP_KERNEL, unless (b) or (c)
+ * apply or your are in a storage driver's block io path;
+ * (5) USB probe and disconnect can use GFP_KERNEL unless (b) or (c) apply; and
+ * (6) changing firmware on a running storage or net device uses
+ * GFP_NOIO, unless b) or c) apply
+ *
+ */
+int usb_submit_urb(struct urb *urb, int mem_flags)
+{
+ int pipe, temp, max;
+ struct usb_device *dev;
+ struct usb_operations *op;
+ int is_out;
+
+ if (!urb || urb->hcpriv || !urb->complete)
+ return -EINVAL;
+ if (!(dev = urb->dev) ||
+ (dev->state < USB_STATE_DEFAULT) ||
+ (!dev->bus) || (dev->devnum <= 0))
+ return -ENODEV;
+ if (dev->state == USB_STATE_SUSPENDED)
+ return -EHOSTUNREACH;
+ if (!(op = dev->bus->op) || !op->submit_urb)
+ return -ENODEV;
+
+ urb->status = -EINPROGRESS;
+ urb->actual_length = 0;
+ urb->bandwidth = 0;
+
+ /* Lots of sanity checks, so HCDs can rely on clean data
+ * and don't need to duplicate tests
+ */
+ pipe = urb->pipe;
+ temp = usb_pipetype (pipe);
+ is_out = usb_pipeout (pipe);
+
+ if (!usb_pipecontrol (pipe) && dev->state < USB_STATE_CONFIGURED)
+ return -ENODEV;
+
+ /* FIXME there should be a sharable lock protecting us against
+ * config/altsetting changes and disconnects, kicking in here.
+ * (here == before maxpacket, and eventually endpoint type,
+ * checks get made.)
+ */
+
+ max = usb_maxpacket (dev, pipe, is_out);
+ if (max <= 0) {
+ dev_dbg(&dev->dev,
+ "bogus endpoint ep%d%s in %s (bad maxpacket %d)\n",
+ usb_pipeendpoint (pipe), is_out ? "out" : "in",
+ __FUNCTION__, max);
+ return -EMSGSIZE;
+ }
+
+ /* periodic transfers limit size per frame/uframe,
+ * but drivers only control those sizes for ISO.
+ * while we're checking, initialize return status.
+ */
+ if (temp == PIPE_ISOCHRONOUS) {
+ int n, len;
+
+ /* "high bandwidth" mode, 1-3 packets/uframe? */
+ if (dev->speed == USB_SPEED_HIGH) {
+ int mult = 1 + ((max >> 11) & 0x03);
+ max &= 0x07ff;
+ max *= mult;
+ }
+
+ if (urb->number_of_packets <= 0)
+ return -EINVAL;
+ for (n = 0; n < urb->number_of_packets; n++) {
+ len = urb->iso_frame_desc [n].length;
+ if (len < 0 || len > max)
+ return -EMSGSIZE;
+ urb->iso_frame_desc [n].status = -EXDEV;
+ urb->iso_frame_desc [n].actual_length = 0;
+ }
+ }
+
+ /* the I/O buffer must be mapped/unmapped, except when length=0 */
+ if (urb->transfer_buffer_length < 0)
+ return -EMSGSIZE;
+
+#ifdef DEBUG
+ /* stuff that drivers shouldn't do, but which shouldn't
+ * cause problems in HCDs if they get it wrong.
+ */
+ {
+ unsigned int orig_flags = urb->transfer_flags;
+ unsigned int allowed;
+
+ /* enforce simple/standard policy */
+ allowed = URB_ASYNC_UNLINK; // affects later unlinks
+ allowed |= (URB_NO_TRANSFER_DMA_MAP | URB_NO_SETUP_DMA_MAP);
+ allowed |= URB_NO_INTERRUPT;
+ switch (temp) {
+ case PIPE_BULK:
+ if (is_out)
+ allowed |= URB_ZERO_PACKET;
+ /* FALLTHROUGH */
+ case PIPE_CONTROL:
+ allowed |= URB_NO_FSBR; /* only affects UHCI */
+ /* FALLTHROUGH */
+ default: /* all non-iso endpoints */
+ if (!is_out)
+ allowed |= URB_SHORT_NOT_OK;
+ break;
+ case PIPE_ISOCHRONOUS:
+ allowed |= URB_ISO_ASAP;
+ break;
+ }
+ urb->transfer_flags &= allowed;
+
+ /* fail if submitter gave bogus flags */
+ if (urb->transfer_flags != orig_flags) {
+ err ("BOGUS urb flags, %x --> %x",
+ orig_flags, urb->transfer_flags);
+ return -EINVAL;
+ }
+ }
+#endif
+ /*
+ * Force periodic transfer intervals to be legal values that are
+ * a power of two (so HCDs don't need to).
+ *
+ * FIXME want bus->{intr,iso}_sched_horizon values here. Each HC
+ * supports different values... this uses EHCI/UHCI defaults (and
+ * EHCI can use smaller non-default values).
+ */
+ switch (temp) {
+ case PIPE_ISOCHRONOUS:
+ case PIPE_INTERRUPT:
+ /* too small? */
+ if (urb->interval <= 0)
+ return -EINVAL;
+ /* too big? */
+ switch (dev->speed) {
+ case USB_SPEED_HIGH: /* units are microframes */
+ // NOTE usb handles 2^15
+ if (urb->interval > (1024 * 8))
+ urb->interval = 1024 * 8;
+ temp = 1024 * 8;
+ break;
+ case USB_SPEED_FULL: /* units are frames/msec */
+ case USB_SPEED_LOW:
+ if (temp == PIPE_INTERRUPT) {
+ if (urb->interval > 255)
+ return -EINVAL;
+ // NOTE ohci only handles up to 32
+ temp = 128;
+ } else {
+ if (urb->interval > 1024)
+ urb->interval = 1024;
+ // NOTE usb and ohci handle up to 2^15
+ temp = 1024;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+ /* power of two? */
+ while (temp > urb->interval)
+ temp >>= 1;
+ urb->interval = temp;
+ }
+
+ return op->submit_urb (urb, mem_flags);
+}
+
+/*-------------------------------------------------------------------*/
+
+/**
+ * usb_unlink_urb - abort/cancel a transfer request for an endpoint
+ * @urb: pointer to urb describing a previously submitted request,
+ * may be NULL
+ *
+ * This routine cancels an in-progress request. URBs complete only
+ * once per submission, and may be canceled only once per submission.
+ * Successful cancelation means the requests's completion handler will
+ * be called with a status code indicating that the request has been
+ * canceled (rather than any other code) and will quickly be removed
+ * from host controller data structures.
+ *
+ * In the past, clearing the URB_ASYNC_UNLINK transfer flag for the
+ * URB indicated that the request was synchronous. This usage is now
+ * deprecated; if the flag is clear the call will be forwarded to
+ * usb_kill_urb() and the return value will be 0. In the future, drivers
+ * should call usb_kill_urb() directly for synchronous unlinking.
+ *
+ * When the URB_ASYNC_UNLINK transfer flag for the URB is set, this
+ * request is asynchronous. Success is indicated by returning -EINPROGRESS,
+ * at which time the URB will normally have been unlinked but not yet
+ * given back to the device driver. When it is called, the completion
+ * function will see urb->status == -ECONNRESET. Failure is indicated
+ * by any other return value. Unlinking will fail when the URB is not
+ * currently "linked" (i.e., it was never submitted, or it was unlinked
+ * before, or the hardware is already finished with it), even if the
+ * completion handler has not yet run.
+ *
+ * Unlinking and Endpoint Queues:
+ *
+ * Host Controller Drivers (HCDs) place all the URBs for a particular
+ * endpoint in a queue. Normally the queue advances as the controller
+ * hardware processes each request. But when an URB terminates with any
+ * fault (such as an error, or being unlinked) its queue stops, at least
+ * until that URB's completion routine returns. It is guaranteed that
+ * the queue will not restart until all its unlinked URBs have been fully
+ * retired, with their completion routines run, even if that's not until
+ * some time after the original completion handler returns.
+ *
+ * This means that USB device drivers can safely build deep queues for
+ * large or complex transfers, and clean them up reliably after any sort
+ * of aborted transfer by unlinking all pending URBs at the first fault.
+ *
+ * Note that an URB terminating early because a short packet was received
+ * will count as an error if and only if the URB_SHORT_NOT_OK flag is set.
+ * Also, that all unlinks performed in any URB completion handler must
+ * be asynchronous.
+ *
+ * Queues for isochronous endpoints are treated differently, because they
+ * advance at fixed rates. Such queues do not stop when an URB is unlinked.
+ * An unlinked URB may leave a gap in the stream of packets. It is undefined
+ * whether such gaps can be filled in.
+ *
+ * When a control URB terminates with an error, it is likely that the
+ * status stage of the transfer will not take place, even if it is merely
+ * a soft error resulting from a short-packet with URB_SHORT_NOT_OK set.
+ */
+int usb_unlink_urb(struct urb *urb)
+{
+ if (!urb)
+ return -EINVAL;
+ if (!(urb->transfer_flags & URB_ASYNC_UNLINK)) {
+#ifdef CONFIG_DEBUG_KERNEL
+ if (printk_ratelimit()) {
+ printk(KERN_NOTICE "usb_unlink_urb() is deprecated for "
+ "synchronous unlinks. Use usb_kill_urb() instead.\n");
+ WARN_ON(1);
+ }
+#endif
+ usb_kill_urb(urb);
+ return 0;
+ }
+ if (!(urb->dev && urb->dev->bus && urb->dev->bus->op))
+ return -ENODEV;
+ return urb->dev->bus->op->unlink_urb(urb, -ECONNRESET);
+}
+
+/**
+ * usb_kill_urb - cancel a transfer request and wait for it to finish
+ * @urb: pointer to URB describing a previously submitted request,
+ * may be NULL
+ *
+ * This routine cancels an in-progress request. It is guaranteed that
+ * upon return all completion handlers will have finished and the URB
+ * will be totally idle and available for reuse. These features make
+ * this an ideal way to stop I/O in a disconnect() callback or close()
+ * function. If the request has not already finished or been unlinked
+ * the completion handler will see urb->status == -ENOENT.
+ *
+ * While the routine is running, attempts to resubmit the URB will fail
+ * with error -EPERM. Thus even if the URB's completion handler always
+ * tries to resubmit, it will not succeed and the URB will become idle.
+ *
+ * This routine may not be used in an interrupt context (such as a bottom
+ * half or a completion handler), or when holding a spinlock, or in other
+ * situations where the caller can't schedule().
+ */
+void usb_kill_urb(struct urb *urb)
+{
+ if (!(urb && urb->dev && urb->dev->bus && urb->dev->bus->op))
+ return;
+ spin_lock_irq(&urb->lock);
+ ++urb->reject;
+ spin_unlock_irq(&urb->lock);
+
+ urb->dev->bus->op->unlink_urb(urb, -ENOENT);
+ wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0);
+
+ spin_lock_irq(&urb->lock);
+ --urb->reject;
+ spin_unlock_irq(&urb->lock);
+}
+
+EXPORT_SYMBOL(usb_init_urb);
+EXPORT_SYMBOL(usb_alloc_urb);
+EXPORT_SYMBOL(usb_free_urb);
+EXPORT_SYMBOL(usb_get_urb);
+EXPORT_SYMBOL(usb_submit_urb);
+EXPORT_SYMBOL(usb_unlink_urb);
+EXPORT_SYMBOL(usb_kill_urb);
+