The unused space in the doorbell is now marked as RsvdZ, not RsvdP, so
we can avoid reading the doorbell before writing it.

Update the doorbell-related defines to produce the entire doorbell value
from a single macro.  Document the doorbell format in a comment.
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

printk_ratelimit() is misused in xhci-ring.c.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

dev_dbg() is used to print ordinary transfer messages in xhci-ring.c.
System log messages will be flushed if CONFIG_USB_DEBUG is set. Replace the
dev_dbg() with xhci_dbg().
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

giveback_first_trb() controls the cycle bit set of the start_trb, to ensure
that the start_trb is written last and the host controller will receive a
whole td at a time.

However, if the ring is wrapped and cycle bit is toggled to zero, then
giveback_first_trb() will be of no effect. In this case, set the cycle bit of
start_trb to 1 at the beginning and clear it in giveback_first_trb().
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Parameter *td is not used in giveback_first_trb(). Remove it.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Fix the more_trbs_coming field of queue_trb() in isoc transfer.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The original code that resumed the USB bus on a port status change would
only do so when there was a device connected to the port.  If a device was
just disconnected, the event would be queued for khubd, but khubd wouldn't
run.  That would leave the connect status change (CSC) bit set.

If a USB device was plugged into that same port, the xHCI host controller
would set the current connect status (CCS) bit.  But since the CSC bit was
already set, it would not generate an interrupt for a port status change
event.  That would mean the user could "Safely Remove" a device, have the
bus suspend, disconnect the device, re-plug it in, and then the device
would never be enumerated.

Plugging in a different device on another port would cause the bus to
resume, and khubd would notice the re-connected device.  Running lsusb
would also resume the bus, leading users to report the problem "went away"
when using diagnostic tools.

The solution is to resume the bus when a port status change event is
received, regardless of the port status.

Thank you very much to Maddog for helping me track down this Heisenbug.

This patch should be queued for the 2.6.37 stable tree.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: NJon 'maddog' Hall <maddog@li.org>
Tested-by: NAndiry Xu <andiry.xu@amd.com>
Cc: stable@kernel.org

If the xHCI host controller shares an interrupt line with another device,
the xHCI driver needs to check if the interrupt was generated by its
hardware.  Unfortunately, the user will see a ton of "Spurious interrupt."
lines if the other hardware interrupts often.  Lawrence found his dmesg
output cluttered with this output when the xHCI host shared an interrupt
with his i915 hardware.

Remove the warning, as sharing an interrupt is a normal thing.

This should be applied to the 2.6.36 stable tree.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: NLawrence Rust <lvr@softsystem.co.uk>
Cc: stable@kernel.org

This commit implements port remote wakeup.

When a port is in U3 state and resume signaling is detected from a device,
the port transitions to the Resume state, and the xHC generates a Port Status
Change Event.

For USB3 port, software write a '0' to the PLS field to complete the resume
signaling. For USB2 port, the resume should be signaling for at least 20ms,
irq handler set a timer for port remote wakeup, and then finishes process in
hub_control GetPortStatus.

Some codes are borrowed from EHCI code.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add software trigger USB device suspend resume function hook.
Do port suspend & resume in terms of xHCI spec.

Port Suspend:
Stop all endpoints via Stop Endpoint Command with Suspend (SP) flag set.
Place individual ports into suspend mode by writing '3' for Port Link State
(PLS) field into PORTSC register. This can only be done when the port is in
Enabled state. When writing, the Port Link State Write Strobe (LWS) bit shall
be set to '1'.
Allocate an xhci_command and stash it in xhci_virt_device to wait completion for
the last Stop Endpoint Command.  Use the Suspend bit in TRB to indicate the Stop
Endpoint Command is for port suspend. Based on Sarah's suggestion.

Port Resume:
Write '0' in PLS field, device will transition to running state.
Ring an endpoints' doorbell to restart it.

Ref: USB device remote wake need another patch to implement. For details of
how USB subsystem do power management, please see:
    Documentation/usb/power-management.txt
Signed-off-by: NCrane Cai <crane.cai@amd.com>
Signed-off-by: NLibin Yang <libin.yang@amd.com>
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch fixes a isoc transfer bug reported by Sander Eikelenboom.
When ep->skip is set, endpoint ring dequeue pointer should be updated
when processed every missed td. Although ring dequeue pointer will also
be updated when ep->skip is clear, leave it intact during missed tds
processing may cause two issues:

1). If the very next valid transfer following missed tds is a short
transfer, its actual_length will be miscalculated;
2). If there are too many missed tds during transfer, new inserted tds
may found the transfer ring full and urb enqueue fails.
Reported-by: NSander Eikelenboom <linux@eikelenboom.it>
Tested-by: NSander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The code to increment the TRB pointer has a slight ambiguity that could
lead to a bug on different compilers.  The ANSI C specification does not
specify the precedence of the assignment operator over the postfix
operator.  gcc 4.4 produced the correct code (increment the pointer and
assign the value), but a MIPS compiler that one of John's clients used
assigned the old (unincremented) value.

Remove the unnecessary assignment to make all compilers produce the
correct assembly.
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

To tell the host controller that there are transfers on the endpoint
rings, we need to ring the endpoint doorbell.  This is a PCI MMIO write,
which can be delayed until another register read is queued.

The previous code would flush the doorbell write by reading the doorbell
register after the write.  This may take time, and it's not necessary to
force the host controller to know about the transfers right away.  Don't
flush the doorbell register writes.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The interrupter register set includes a register that says whether interrupts
are pending for each event ring (the IP bit).  Each MSI-X vector will get its
own interrupter set with separate IP bits.  The status register includes an
"Event Interrupt (EINT)" bit that is set when an IP bit is set in any of the
interrupters.

When PCI interrupts are used, the EINT bit exactly mirrors the IP bit in the
single interrupter set, and it is a waste of time to check both registers when
trying to figure out if the xHC interrupted or another device on the shared IRQ
line interrupted.  Only check the IP bit to reduce register reads.

The IP bit is automatically cleared by the xHC when MSI or MSI-X is enabled.  It
doesn't make sense to read that register to check for shared interrupts (since
MSI and MSI-X aren't shared).  It also doesn't make sense to write to that
register to clear the IP bit, since it is cleared by the hardware.

We can tell whether MSI or MSI-X is enabled by looking at the irq number in
hcd->irq.  If it's -1, we know MSI or MSI-X is enabled.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that the event handler functions no longer use xhci_set_hc_event_deq()
to update the event ring dequeue pointer, that function is not used by
anything in xhci-ring.c.  Move that function into xhci-mem.c and make it
static.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The xHCI specification suggests that writing the hardware event ring dequeue
pointer register too often can be an expensive operation for the xHCI hardware
to manage.  It suggests minimizing the number of writes to that register.

Originally, the driver wrote the event ring dequeue pointer after each
event was processed.  Depending on how the event ring moderation register
is set up and how fast the transfers are completing, there may be several
events processed for each interrupt.  This patch makes the hardware event
ring dequeue pointer be written only once per interrupt.

Make the transfer event handler and port status event handler only write
the software event ring dequeue pointer.  Move the updating of the
hardware event ring dequeue pointer into the interrupt function.  Move the
contents of xhci_set_hc_event_deq() into the interrupt handler.  The
interrupt handler must clear the event handler busy flag, so it might as
well also write the dequeue pointer to the same register.  This eliminates
two 32-bit PCI reads and two 32-bit PCI writes.
Reported-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

xhci_handle_event() is now only called from within xhci-ring.c, so make it
static.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Remove a duplicate register read of the interrupt pending register from
xhci_irq().  Also, remove waiting on the posted write of that register.
The host will see it eventually.  It will probably read the register
itself before deciding whether to interrupt the system again, forcing the
posted write to complete.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

When we move xhci_work() into xhci_irq(), we don't need to read the operational
register status field twice.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Most of the work for interrupt handling is done in xhci-ring.c, so it makes
sense to move the functions that are first called when an interrupt happens
(xhci_irq() or xhci_msi_irq()) into xhci-ring.c, so that the compiler can better
optimize them.

Shorten some lines to make it pass checkpatch.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

I've been using perf to measure the top symbols while transferring 1GB of data
on a USB 3.0 drive with dd.  This is using the raw disk with /dev/sdb, with a
block size of 1K.

During performance testing, the top symbol was xhci_triad_to_transfer_ring(), a
function that should return immediately if streams are not enabled for an
endpoint.  It turned out that the functions to find the endpoint ring was
defined in xhci-mem.c and used in xhci-ring.c and xhci-hcd.c.  I moved a copy of
xhci_triad_to_transfer_ring() and xhci_urb_to_transfer_ring() into xhci-ring.c
and declared them static.  I also made a static version of
xhci_urb_to_transfer_ring() in xhci.c.

This improved throughput on a 1GB read of the raw disk with dd from
186MB/s to 195MB/s, and perf reported sampling the xhci_triad_to_transfer_ring()
0.06% of the time, rather than 9.26% of the time.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch implements isochronous urb enqueue and interrupt handler part.

When an isochronous urb is passed to xHCI driver, first check the transfer
ring to guarantee there is enough room for the whole urb. Then update the
start_frame and interval field of the urb. Always assume URB_ISO_ASAP
is set, and never use urb->start_frame as input.

The number of isoc TDs is equal to urb->number_of_packets. One isoc TD is
consumed every Interval. Each isoc TD consists of an Isoch TRB chained to
zero or more Normal TRBs.

Call prepare_transfer for each TD to do initialization; then calculate the
number of TRBs needed for each TD. If the data required by an isoc TD is
physically contiguous (not crosses a page boundary), then only one isoc TRB
is needed; otherwise one or more additional normal TRB shall be chained to
the isoc TRB by the host.

Set TRB_IOC to the last TRB of each isoc TD. Do not ring endpoint doorbell
to start xHC procession until all the TDs are inserted to the endpoint
transer ring.

In irq handler, update urb status and actual_length, increase
urb_priv->td_cnt. When all the TDs are completed(td_cnt is equal to
urb_priv->length), giveback the urb to usbcore.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add urb_priv data structure to xHCI driver. This structure allows multiple
xhci TDs to be linked to one urb, which is essential for isochronous
transfer. For non-isochronous urb, only one TD is needed for one urb;
for isochronous urb, the TD number for the urb is equal to
urb->number_of_packets.

The length field of urb_priv indicates the number of TDs in the urb.
The td_cnt field indicates the number of TDs already processed by xHC.
When td_cnt matches length, the urb can be given back to usbcore.

When an urb is dequeued or cancelled, add all the unprocessed TDs to the
endpoint's cancelled_td_list. When process a cancelled TD, increase
td_cnt field. When td_cnt equals urb_priv->length, giveback the
cancelled urb.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch adds mechanism to process Missed Service Error Event.
Sometimes the xHC is unable to process the isoc TDs in time, it will
generate Missed Service Error Event. In this case some TDs on the ring are
not processed and missed. When encounter a Missed Servce Error Event, set
the skip flag of the ep, and process the missed TDs until reach the next
processed TD, then clear the skip flag.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch adds new cases to trb_comp_code switch, and moves
the switch judgment ahead of fetching td.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Remove redundant print messages in the interrupt context.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch moves the bulk and interrupt td processing part in
handle_tx_event() into a separate function process_bulk_intr_td().
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch moves the ctrl td processing part in handle_tx_event()
into a separate function process_ctrl_td().
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch moves the td universal processing part in handle_tx_event()
into a separate function finish_td().

if finish_td() returns 1, it indicates the urb can be given back.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Commit 6c12db90 also seems to have
introduced a bug that is triggered when the command ring is about to wrap.
The inc_enq() function will not have moved the enqueue pointer past the
link TRB.  It is supposed to be moved past the link TRB in prepare_ring(),
which should be called before a TD is enqueued.  However, the
queue_command() function never calls the prepare_ring() function because
prepare_ring() is only supposed to be used for endpoint rings.  That means
the enqueue pointer will not be moved past the link TRB, and will get
overwritten.

The fix is to make queue_command() call prepare_ring() with a fake
endpoint status (set to running).  Then the enqueue pointer will get moved
past the link TRB.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Commit 6c12db90 introduced a bug for
control transfers.  The patch was supposed to change when the link TRBs at
the end of each ring segment were given to the hardware.  If a transfer
descriptor (TD) ended just before the link TRB, the code wouldn't give
back the link TRB to the hardware; instead it would be given back in
prepare_ring() just before the next TD was enqueued at the top of the
ring.

Unfortunately, the code relied on checking the chain bit of the TRB to
determine whether the TD ended just before the link TRB.  It assumed that
the ring enqueuing code would call prepare_ring() before enqueuing the
next TD.  However, control transfers are made of multiple TDs, and
prepare_ring() is only called once before enqueuing two or three TDs.

If the first or second TD of the control transfer ended just before the
link TRB, then the code in inc_enq() would not move the enqueue pointer
past the link TRB, and the link TRB would get overwritten.  This would
cause the xHCI driver to start writing to memory past the ring segment,
and eventually the system would crash or hang.

The fix is to add a flag to inc_enq() that says whether the caller will
enqueue more TDs before calling prepare_ring().  If the chain bit is
cleared (meaning this is the last TRB in a TD), and the caller will not
enqueue more TDs, then we defer giving back the link TRB.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The NEC xHCI host controller firmware version can be found by putting a
vendor-specific command on the command ring and extracting the BCD
encoded-version out of the vendor-specific event TRB.

The firmware version debug line in dmesg will look like:

xhci_hcd 0000:05:00.0: NEC firmware version 30.21

(NEC merged with Renesas Technologies and became Renesas Electronics on
April 1, 2010.  I have their OK to merge this vendor-specific code.)
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Satoshi Otani <satoshi.otani.xm@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Macro TRB_TYPE is misused in some places. Fix the wrong usage.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Change transfer ring behavior to not follow/activate link TRBs
until active TRBs are queued after it.  This change affects
the behavior when a TD ends just before a link TRB.
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

After using state stored in xhci_virt_ep to clean up a stalled endpoint,
be sure to set the stalled stream ID back to 0.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Change the type of the URB's 'sg' pointer from a usb_sg_request to
a scatterlist.  This allows drivers to submit scatter-gather lists
without using the usb_sg_wait() interface.  It has the added benefit
of removing the typecasts that were added as part of patch as1368 (and
slightly decreasing the number of pointer dereferences).
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Reviewed-by: NAlan Stern <stern@rowland.harvard.edu>
Tested-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fix usb sparse warnings:

drivers/usb/host/isp1362-hcd.c:2220:50: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:43:24: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:49:24: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:161:24: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:198:16: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:319:31: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:1231:33: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-pci.c:177:23: warning: non-ANSI function declaration of function 'xhci_register_pci'
drivers/usb/host/xhci-pci.c:182:26: warning: non-ANSI function declaration of function 'xhci_unregister_pci'
drivers/usb/host/xhci-ring.c:342:32: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:525:34: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1009:32: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1031:32: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1041:16: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1096:30: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1100:27: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:224:27: warning: symbol 'xhci_alloc_container_ctx' was not declared. Should it be static?
drivers/usb/host/xhci-mem.c:242:6: warning: symbol 'xhci_free_container_ctx' was not declared. Should it be static?
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: Lothar Wassmann <LW@KARO-electronics.de>
Signed-off By: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Much of the xHCI driver code assumes that endpoints only have one ring.
Now an endpoint can have one ring per enabled stream ID, so correct that
assumption.  Use functions that translate the stream_id field in the URB
or the DMA address of a TRB into the correct stream ring.

Correct the polling loop to print out all enabled stream rings.  Make the
URB cancellation routine find the correct stream ring if the URB has
stream_id set.  Make sure the URB enqueueing routine does the same.  Also
correct the code that handles stalled/halted endpoints.

Check that commands and registers that can take stream IDs handle them
properly.  That includes ringing an endpoint doorbell, resetting a
stalled/halted endpoint, and setting a transfer ring dequeue pointer
(since that command can set the dequeue pointer in a stream context or an
endpoint context).

Correct the transfer event handler to translate a TRB DMA address into the
stream ring it was enqueued to.  Make the code to allocate and prepare TD
structures adds the TD to the right td_list for the stream ring.  Make
sure the code to give the first TRB in a TD to the hardware manipulates
the correct stream ring.

When an endpoint stalls, store the stream ID of the stream ring that
stalled in the xhci_virt_ep structure.  Use that instead of the stream ID
in the URB, since an URB may be re-used after it is given back after a
non-control endpoint stall.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add support for allocating streams for USB 3.0 bulk endpoints.  See
Documentation/usb/bulk-streams.txt for more information about how and why
you would use streams.

When an endpoint has streams enabled, instead of having one ring where all
transfers are enqueued to the hardware, it has several rings.  The ring
dequeue pointer in the endpoint context is changed to point to a "Stream
Context Array".  This is basically an array of pointers to transfer rings,
one for each stream ID that the driver wants to use.

The Stream Context Array size must be a power of two, and host controllers
can place a limit on the size of the array (4 to 2^16 entries).  These
two facts make calculating the size of the Stream Context Array and the
number of entries actually used by the driver a bit tricky.

Besides the Stream Context Array and rings for all the stream IDs, we need
one more data structure.  The xHCI hardware will not tell us which stream
ID a transfer event was for, but it will give us the slot ID, endpoint
index, and physical address for the TRB that caused the event.  For every
endpoint on a device, add a radix tree to map physical TRB addresses to
virtual segments within a stream ring.

Keep track of whether an endpoint is transitioning to using streams, and
don't enqueue any URBs while that's taking place.  Refuse to transition an
endpoint to streams if there are already URBs enqueued for that endpoint.

We need to make sure that freeing streams does not fail, since a driver's
disconnect() function may attempt to do this, and it cannot fail.
Pre-allocate the command structure used to issue the Configure Endpoint
command, and reserve space on the command ring for each stream endpoint.
This may be a bit overkill, but it is permissible for the driver to
allocate all streams in one call and free them in multiple calls.  (It is
not advised, however, since it is a waste of resources and time.)

Even with the memory and ring room pre-allocated, freeing streams can
still fail because the xHC rejects the configure endpoint command.  It is
valid (by the xHCI 0.96 spec) to return a "Bandwidth Error" or a "Resource
Error" for a configure endpoint command.  We should never see a Bandwidth
Error, since bulk endpoints do not effect the reserved bandwidth.  The
host controller can still return a Resource Error, but it's improbable
since the xHC would be going from a more resource-intensive configuration
(streams) to a less resource-intensive configuration (no streams).

If the xHC returns a Resource Error, the endpoint will be stuck with
streams and will be unusable for drivers.  It's an unavoidable consequence
of broken host controller hardware.

Includes bug fixes from the original patch, contributed by
John Youn <John.Youn@synopsys.com> and Andy Green <AGreen@PLXTech.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>