Narrow down time spent holding the xHCI spinlock so that it's only used to
protect the xHCI rings, not as mutual exclusion.  Stop allocating memory
while holding the spinlock and calling xhci_alloc_virt_device() and
xhci_endpoint_init().

The USB core should have locking in it to prevent device state to be
manipulated by more than one kernel thread.  E.g. you can't free a device
while you're in the middle of setting a new configuration.  So removing
the locks from the sections where xhci_alloc_dev() and
xhci_reset_bandwidth() touch xHCI's representation of the device should be
OK.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Mask off the lower 16 bits of the interrupt control register, instead of
masking off the upper 16 bits.  The interrupt moderation interval field is
the lower 16 bytes, and is set to 0x4000 (1ms) by default.  The previous
code was adding 40 us to the default value, instead of setting it to 40
us.  This makes performance really bad.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The packed attribute allows gcc to muck with the alignment of data
structures, which may lead to byte-wise writes that break atomicity of
writes.  Packed should only be used when the compile may add undesired
padding to the structure.  Each element of the structure will be aligned
by C based on its size and the size of the elements around it.  E.g. a u64
would be aligned on an 8 byte boundary, the next u32 would be aligned on a
four byte boundary, etc.

Since most of the xHCI structures contain only u32 bit values, removing
the packed attribute for them should be harmless.  (A future patch will
change some of the twin 32-bit address fields to one 64-bit field, but all
those places have an even number of 32-bit fields before them, so the
alignment should be correct.)  Add BUILD_BUG_ON statements to check that
the compiler doesn't add padding to the data structures that have a
hardware-defined layout.

While we're modifying the registers, change the name of intr_reg to
xhci_intr_reg to avoid global conflicts.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Greg KH introduced a bug into xhci_trb_virt_to_dma() when he changed the
type of offset to dma_addr_t from unsigned int and dropped the casts to
unsigned int around the virtual address pointer subtraction.

trb and seg->trbs are both valid pointers to virtual addresses, so the
compiler will mod the subtraction by the size of union trb (16 bytes).
segment_offset is an unsigned long, which is guaranteed to be at least as
big as a void *.

Drop the void * casts in the first if statement because trb and seg->trbs
are both pointers of the same type (pointers to union trb).
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Replace if-elseif-else with switch-case
to keep the code consistent which is semantically same

Switch-case is used here,
http://www.spinics.net/lists/linux-usb/msg17201.html
Making consistent at other places in usb/core

Also easier to read and maintain when USB4.0, 5.0, ... comes
Signed-off-by: NViral Mehta <viral.mehta@einfochips.com>
Tested-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

xhci-mem.c includes calls to dma_pool_alloc() and other functions defined
in linux/dmapool.h.  Make sure to include that header file.
Reported-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Make sure the error path in xhci_urb_enqueue() releases the spinlock
before it returns.  Reported by Oliver in
	http://marc.info/?l=linux-usb&m=124091637311832&w=2Reported-by: NOliver Neukum <oliver@neukum.org>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Differentiate between SuperSpeed endpoint companion descriptor and the
wireless USB endpoint companion descriptor.  Make all structure names for
this descriptor have "ss" (SuperSpeed) in them.  David Vrabel asked for
this change in http://marc.info/?l=linux-usb&m=124091465109367&w=2Reported-by: NDavid Vrabel <david.vrabel@csr.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Force the compiler to write the cycle bit of the Link TRB last.  This
ensures that the hardware doesn't think it owns the Link TRB before we set
the chain bit.  Reported by Oliver in this thread:
	http://marc.info/?l=linux-usb&m=124091532410219&w=2Reported-by: NOliver Neukum <oliver@neukum.org>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Drop spinlock in xhci_irq() error path.
This fixes the issue reported by Oliver Neukum on this thread:
	http://marc.info/?l=linux-usb&m=124090924401444&w=2

Remove unnecessary register read reported by Viral Mehta:
	http://marc.info/?l=linux-usb&m=124091326007398&w=2Reported-by: NOliver Neukum <oliver@neukum.org>
Reported-by: NViral Mehta <viral.mehta@einfochips.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Make all globally visible functions start with xhci_ and mark functions as
static if they're only called within the same C file.  Fix some long lines
while we're at it.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Make sure to preserve all bits *except* the TRB_CHAIN bit when giving a
Link TRB to the hardware.  We need to save things like TRB type and the
toggle bit in the control dword.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The 0.95 xHCI spec says that if the xHCI HW support 64-bit addressing, you
must write the whole 64-bit address as one atomic operation, or write the
low 32 bits, and then the high 32 bits.  I had the register writes
swapped in some places.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This fixes the warning:
drivers/usb/host/xhci.h:1083: warning: passing argument 1 of ‘xhci_to_hcd’ discards qualifiers from pointer target type
drivers/usb/host/xhci.h:1083: warning: passing argument 1 of ‘xhci_to_hcd’ discards qualifiers from pointer target type
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>

Turns out someone never built this code on a 64bit platform.

Someone owes me a beer...
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>

The former is way to generic for a global symbol.

Fixes this build error:

drivers/usb/built-in.o: In function `.handle_event': (.text+0x67dd0): multiple definition of `.handle_event'
drivers/pcmcia/built-in.o:(.text+0xcfcc): first defined here
drivers/usb/built-in.o: In function `handle_event': (.opd+0x5bc8): multiple definition of `handle_event'
drivers/pcmcia/built-in.o:(.opd+0xed0): first defined here
Signed-off-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>

Add URB cancellation support to the xHCI host controller driver.  This
currently supports cancellation for endpoints that do not have streams
enabled.

An URB is represented by a number of Transaction Request Buffers (TRBs),
that are chained together to make one (or more) Transaction Descriptors
(TDs) on an endpoint ring.  The ring is comprised of contiguous segments,
linked together with Link TRBs (which may or may not be chained into a TD).

To cancel an URB, we must stop the endpoint ring, make the hardware skip
over the TDs in the URB (either by turning them into No-op TDs, or by
moving the hardware's ring dequeue pointer past the last TRB in the last
TD), and then restart the ring.

There are times when we must drop the xHCI lock during this process, like
when we need to complete cancelled URBs.  We must ensure that additional
URBs can be marked as cancelled, and that new URBs can be enqueued (since
the URB completion handlers can do either).  The new endpoint ring
variables cancels_pending and state (which can only be modified while
holding the xHCI lock) ensure that future cancellation and enqueueing do
not interrupt any pending cancellation code.

To facilitate cancellation, we must keep track of the starting ring
segment, first TRB, and last TRB for each URB.  We also need to keep track
of the list of TDs that have been marked as cancelled, separate from the
list of TDs that are queued for this endpoint.  The new variables and
cancellation list are stored in the xhci_td structure.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add support for bulk URBs that pass scatter gather lists to xHCI.  This allows
xHCI to more efficiently enqueue these transfers, and allows the host
controller to take advantage of USB 3.0 "bursts" for bulk endpoints.

Use requested length to calculate the number of TRBs needed for a scatter gather
list transfer, instead of using the number of sglist entries.  The application
can pass down a scatter gather list that is bigger than it needs for the
requested transfer.

Scatter gather entries can cross 64KB boundaries, so be careful to setup TRBs
such that no buffer crosses a 64KB boundary.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This is the original patch I created before David Vrabel posted a better
patch (http://marc.info/?l=linux-usb&m=123377477209109&w=2) that does
basically the same thing.  This patch will get replaced with his
(modified) patch later.

Allow USB device drivers that use usb_sg_init() and usb_sg_wait() to push
bulk endpoint scatter gather lists down to the host controller drivers.
This allows host controller drivers to more efficiently enqueue these
transfers, and allows the xHCI host controller to better take advantage of
USB 3.0 "bursts" for bulk endpoints.

This patch currently only enables scatter gather lists for bulk endpoints.
Other endpoint types that use the usb_sg_* functions will not have their
scatter gather lists pushed down to the host controller.  For periodic
endpoints, we want each scatterlist entry to be a separate transfer.
Eventually, HCDs could parse these scatter-gather lists for periodic
endpoints also.  For now, we use the old code and call usb_submit_urb()
for each scatterlist entry.

The caller of usb_sg_init() can request that all bytes in the scatter
gather list be transferred by passing in a length of zero.  Handle that
request for a bulk endpoint under xHCI by walking the scatter gather list
and calculating the length.  We could let the HCD handle a zero length in
this case, but I'm not sure if the core layers in between will get
confused by this.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Allow device drivers to submit URBs to bulk endpoints on devices under an
xHCI host controller.  Share code between the control and bulk enqueueing
functions when it makes sense.

To get the best performance out of bulk transfers, SuperSpeed devices must
have the bMaxBurst size copied from their endpoint companion controller
into the xHCI device context.  This allows the host controller to "burst"
up to 16 packets before it has to wait for the device to acknowledge the
first packet.

The buffers in Transfer Request Blocks (TRBs) can cross page boundaries,
but they cannot cross 64KB boundaries.  The buffer must be broken into
multiple TRBs if a 64KB boundary is crossed.

The sum of buffer lengths in all the TRBs in a Transfer Descriptor (TD)
cannot exceed 64MB.  To work around this, the enqueueing code must enqueue
multiple TDs.  The transfer event handler may incorrectly give back the
URB in this case, if it gets a transfer event that points somewhere in the
first TD.  FIXME later.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Since the xHCI host controller hardware (xHC) has an internal schedule, it
needs a better representation of what devices are consuming bandwidth on
the bus.  Each device is represented by a device context, with data about
the device, endpoints, and pointers to each endpoint ring.

We need to update the endpoint information for a device context before a
new configuration or alternate interface setting is selected.  We setup an
input device context with modified endpoint information and newly
allocated endpoint rings, and then submit a Configure Endpoint Command to
the hardware.

The host controller can reject the new configuration if it exceeds the bus
bandwidth, or the host controller doesn't have enough internal resources
for the configuration.  If the command fails, we still have the older
device context with the previous configuration.  If the command succeeds,
we free the old endpoint rings.

The root hub isn't a real device, so always say yes to any bandwidth
changes for it.

The USB core will enable, disable, and then enable endpoint 0 several
times during the initialization sequence.  The device will always have an
endpoint ring for endpoint 0 and bandwidth allocated for that, unless the
device is disconnected or gets a SetAddress 0 request.  So we don't pay
attention for when xhci_check_bandwidth() is called for a re-add of
endpoint 0.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Originally, the USB core had no support for allocating bandwidth when a
particular configuration or alternate setting for an interface was
selected.  Instead, the device driver's URB submission would fail if
there was not enough bandwidth for a periodic endpoint.  Drivers could
work around this, by using the scatter-gather list API to guarantee
bandwidth.

This patch adds host controller API to allow the USB core to allocate or
deallocate bandwidth for an endpoint.  Endpoints are added to or dropped
from a copy of the current schedule by calling add_endpoint() or
drop_endpoint(), and then the schedule is atomically evaluated with a
call to check_bandwidth().  This allows all the endpoints for a new
configuration or alternate setting to be added at the same time that the
endpoints from the old configuration or alt setting are dropped.

Endpoints must be added to the schedule before any URBs are submitted to
them.  The HCD must be allowed to reject a new configuration or alt
setting before the control transfer is sent to the device requesting the
change.  It may reject the change because there is not enough bandwidth,
not enough internal resources (such as memory on an embedded host
controller), or perhaps even for security reasons in a virtualized
environment.

If the call to check_bandwidth() fails, the USB core must call
reset_bandwidth().  This causes the schedule to be reverted back to the
state it was in just after the last successful check_bandwidth() call.

If the call succeeds, the host controller driver (and hardware) will have
changed its internal state to match the new configuration or alternate
setting.  The USB core can then issue a control transfer to the device to
change the configuration or alt setting.  This allows the core to test new
configurations or alternate settings before unbinding drivers bound to
interfaces in the old configuration.

WIP:

The USB core must add endpoints from all interfaces in a configuration
to the schedule, because a driver may claim that interface at any time.
A slight optimization might be to add the endpoints to the schedule once
a driver claims that interface.  FIXME

This patch does not cover changing alternate settings, but it does
handle a configuration change or de-configuration.  FIXME

The code for managing the schedule is currently HCD specific.  A generic
scheduling algorithm could be added for host controllers without
built-in scheduling support.  For now, if a host controller does not
define the check_bandwidth() function, the call to
usb_hcd_check_bandwidth() will always succeed.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The USB 3.0 bus specification added an "Endpoint Companion" descriptor that is
supposed to follow all SuperSpeed Endpoint descriptors.  This descriptor is used
to extend the bus protocol to allow more packets to be sent to an endpoint per
"microframe".  The word microframe was removed from the USB 3.0 specification
because the host controller does not send Start Of Frame (SOF) symbols down the
USB 3.0 wires.

The descriptor defines a bMaxBurst field, which indicates the number of packets
of wMaxPacketSize that a SuperSpeed device can send or recieve in a service
interval.  All non-control endpoints may set this value as high as 16 packets
(bMaxBurst = 15).

The descriptor also allows isochronous endpoints to further specify that they
can send and receive multiple bursts per service interval.  The bmAttributes
allows them to specify a "Mult" of up to 3 (bmAttributes = 2).

Bulk endpoints use bmAttributes to report the number of "Streams" they support.
This was an extension of the endpoint pipe concept to allow multiple mass
storage device commands to be outstanding for one bulk endpoint at a time.  This
should allow USB 3.0 mass storage devices to support SCSI command queueing.
Bulk endpoints can say they support up to 2^16 (65,536) streams.

The information in the endpoint companion descriptor must be stored with the
other device, config, interface, and endpoint descriptors because the host
controller needs to access them quickly, and we need to install some default
values if a SuperSpeed device doesn't provide an endpoint companion descriptor.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Allow device drivers to enqueue URBs to control endpoints on devices under
an xHCI host controller.  Each control transfer is represented by a
series of Transfer Descriptors (TDs) written to an endpoint ring.  There
is one TD for the Setup phase, (optionally) one TD for the Data phase, and
one TD for the Status phase.

Enqueue these TDs onto the endpoint ring that represents the control
endpoint.  The host controller hardware will return an event on the event
ring that points to the (DMA) address of one of the TDs on the endpoint
ring.  If the transfer was successful, the transfer event TRB will have a
completion code of success, and it will point to the Status phase TD.
Anything else is considered an error.

This should work for control endpoints besides the default endpoint, but
that hasn't been tested.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Warn users of URB_NO_SETUP_DMA_MAP about xHCI behavior.

Device drivers can choose to DMA map the setup packet of a control transfer
before submitting the URB to the USB core.  Drivers then set the
URB_NO_SETUP_DMA_MAP and pass in the DMA memory address in setup_dma, instead of
providing a kernel address for setup_packet.  However, xHCI requires that the
setup packet be copied into an internal data structure, and we need a kernel
memory address pointer for that.  Warn users of URB_NO_SETUP_DMA_MAP that they
should provide a valid pointer for setup_packet, along with the DMA address.

FIXME:  I'm not entirely sure how to work around this in the xHCI driver
or USB core.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

xHCI needs to get a "Slot ID" from the host controller and allocate other
data structures for every USB device.  Make usb_alloc_dev() and
usb_release_dev() allocate and free these device structures.  After
setting up the xHC device structures, usb_alloc_dev() must wait for the
hardware to respond to an Enable Slot command.  usb_alloc_dev() fires off
a Disable Slot command and does not wait for it to complete.

When the USB core wants to choose an address for the device, the xHCI
driver must issue a Set Address command and wait for an event for that
command.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add host controller driver API and a slot_id variable to struct
usb_device.  This allows the xHCI host controller driver to ask the
hardware to allocate a slot for the device when a struct usb_device is
allocated.  The slot needs to be allocated at that point because the
hardware can run out of internal resources, and we want to know that very
early in the device connection process.  Don't call this new API for root
hubs, since they aren't real devices.

Add HCD API to let the host controller choose the device address.  This is
especially important for xHCI hardware running in a virtualized
environment.  The guests running under the VM don't need to know which
addresses on the bus are taken, because the hardware picks the address for
them.  Announce SuperSpeed USB devices after the address has been assigned
by the hardware.

Don't use the new get descriptor/set address scheme with xHCI.  Unless
special handling is done in the host controller driver, the xHC can't
issue control transfers before you set the device address.  Support for
the older addressing scheme will be added when the xHCI driver supports
the Block Set Address Request (BSR) flag in the Address Device command.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add functionality for getting port status and hub descriptor for xHCI root
hubs.  This is WIP because the USB 3.0 hub descriptor is different from
the USB 2.0 hub descriptor.  For now, we lie about the root hub descriptor
because the changes won't effect how the core talks to the root hub.
Later we will need to add the USB 3.0 hub descriptor for real hubs, and
this code might change.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch adds a hex route string to each USB device.  The route string is used
by the USB 3.0 host controller to send packets through the device tree.  USB 3.0
hubs use this string to route packets to the correct port.  This is fundamental
bus change from USB 2.0, where all packets were broadcast across the bus.

Devices (including hubs) under a root port receive the route string 0x0.  Every
four bits in the route string represent a port on a hub.  This length works
because USB 3.0 hubs are limited to 15 ports, and USB 2.0 hubs (with potentially
more ports) will never see packets with a route string.  A port number of 0
means the packet is destined for that hub.

For example, a peripheral device might have a route string of 0x00097.
This means the device is connected to port 9 of the hub at depth 1.
The hub at depth 1 is connected to port 7 of a hub at depth 0.
The hub at depth 0 is connected to a root port.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The USB 3.0 bus specification defines a new connection sequence for USB 3.0
hubs and roothubs.  USB 3.0 devices are reset and link trained by the hub
before the port status change notification is sent to the host OS.  This means
that an entire tree of devices can be trained in parallel on power up, and the
OS no longer needs to reset USB 3.0 devices.  Change the USB core's hub port
init sequence so that it does not reset USB 3.0 devices.

The port status change from the roothub and from the USB 3.0 hub will report
the SuperSpeed connect correctly.  This patch currently only handles the
roothub case.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add USB 3.0 root hub descriptors.  This is a kludge because I reused the old
USB 2.0 descriptors, instead of using the new USB 3.0 hub descriptors with
endpoint companion descriptors and other descriptors.  I did this because I
wasn't ready to add USB 3.0 hub changes to khubd.  For now, a USB 3.0 roothub
looks like a USB 2.0 roothub, with a higher speed.

USB 3.0 hubs have no transaction translator (TT).

Make USB core debugging handle super speed ports.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Modify the USB core to handle the new USB 3.0 speed, "SuperSpeed".  This
is 5.0 Gbps (wire speed).  There are probably more places that check for
speed that I've missed.

SuperSpeed devices have a 512 byte endpoint 0 max packet size.  This shows
up as a bMaxPacketSize0 set to 0x09 (see table 9-8 of the USB 3.0 bus
spec).

xHCI spec says that the xHC can handle intervals up to 2^15 microframes.  That
might change when real silicon becomes available.

Add FIXME note for SuperSpeed isochronous endpoints.  They can transmit up
to 16 packets in one "burst" before they wait for an acknowledgment of the
packets.  They can do up to 3 bursts per microframe (determined by the
mult value in the endpoint companion descriptor).  The xHCI driver doesn't
have support for isoc yet, so fix this later.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

xHCI host controllers can optionally implement a no-op test.  This
simple test ensures the OS has correctly setup all basic data structures
and can correctly respond to interrupts from the host controller
hardware.

There are two rings exercised by the no-op test:  the command ring, and
the event ring.

The host controller driver writes a no-op command TRB to the command
ring, and rings the doorbell for the command ring (the first entry in
the doorbell array).  The hardware receives this event, places a command
completion event on the event ring, and fires an interrupt.

The host controller driver sees the interrupt, and checks the event ring
for TRBs it can process, and sees the command completion event.  (See
the rules in xhci-ring.c for who "owns" a TRB.  This is a simplified set
of rules, and may not contain all the details that are in the xHCI 0.95
spec.)

A timer fires every 60 seconds to debug the state of the hardware and
command and event rings.  This timer only runs if
CONFIG_USB_XHCI_HCD_DEBUGGING is 'y'.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Instead of keeping a "frame list" like older host controllers, the xHCI
host controller keeps internal representations of the USB devices, with a
transfer ring per endpoint.  The host controller queues Transfer Request
Blocks (TRBs) to the endpoint ring, and then "rings the doorbell" for that
device.  The host controller processes the transfer, places a transfer
completion event on the event ring, and interrupts the system.

The device context base address array must be allocated by the xHCI host
controller driver, along with the device contexts it points to.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Allocate basic xHCI host controller data structures.  For every xHC, there
is a command ring, an event ring, and a doorbell array.

The doorbell array is used to notify the host controller that work has
been enqueued onto one of the rings.  The host controller driver enqueues
commands on the command ring.  The HW enqueues command completion events
on the event ring and interrupts the system (currently using PCI
interrupts, although the xHCI HW will use MSI interrupts eventually).

All rings and the doorbell array must be allocated by the xHCI host
controller driver.

Each ring is comprised of one or more segments, which consists of 16-byte
Transfer Request Blocks (TRBs) that can be chained to form a Transfer
Descriptor (TD) that represents a multiple-buffer request.  Segments are
linked into a ring using Link TRBs, which means they are dynamically
growable.

The producer of the ring enqueues a TD by writing one or more TRBs in the
ring and toggling the TRB cycle bit for each TRB.  The consumer knows it
can process the TRB when the cycle bit matches its internal consumer cycle
state for the ring.  The consumer cycle state is toggled an odd amount of
times in the ring.

An example ring (a ring must have a minimum of 16 TRBs on it, but that's
too big to draw in ASCII art):

              chain  cycle
               bit    bit
 ------------------------
| TD A TRB 1 |  1  |  1  |<-------------  <-- consumer dequeue ptr
 ------------------------               |     consumer cycle state = 1
| TD A TRB 2 |  1  |  1  |              |
 ------------------------               |
| TD A TRB 3 |  0  |  1  |  segment 1   |
 ------------------------               |
| TD B TRB 1 |  1  |  1  |              |
 ------------------------               |
| TD B TRB 2 |  0  |  1  |              |
 ------------------------               |
| Link TRB   |  0  |  1  |-----         |
 ------------------------     |         |
                              |         |
              chain  cycle    |         |
               bit    bit     |         |
 ------------------------     |         |
| TD C TRB 1 |  0  |  1  |<----         |
 ------------------------               |
| TD D TRB 1 |  1  |  1  |              |
 ------------------------               |
| TD D TRB 2 |  1  |  1  |   segment 2  |
 ------------------------               |
| TD D TRB 3 |  1  |  1  |              |
 ------------------------               |
| TD D TRB 4 |  1  |  1  |              |
 ------------------------               |
| Link TRB   |  1  |  1  |-----         |
 ------------------------     |         |
                              |         |
              chain  cycle    |         |
               bit    bit     |         |
 ------------------------     |         |
| TD D TRB 5 |  1  |  1  |<----         |
 ------------------------               |
| TD D TRB 6 |  0  |  1  |              |
 ------------------------               |
| TD E TRB 1 |  0  |  1  |   segment 3  |
 ------------------------               |
|            |  0  |  0  |              | <-- producer enqueue ptr
 ------------------------               |
|            |  0  |  0  |              |
 ------------------------               |
| Link TRB   |  0  |  0  |---------------
 ------------------------
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add PCI initialization code to take control of the xHCI host controller
away from the BIOS, halt, and reset the host controller.  The xHCI spec
says that BIOSes must give up the host controller within 5 seconds.

Add some host controller glue functions to handle hardware initialization
and memory allocation for the host controller.  The current xHCI
prototypes use PCI interrupts, but the xHCI spec requires MSI-X
interrupts.  Add code to support MSI-X interrupts, but use the PCI
interrupts for now.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This is the first of many patches to add support for USB 3.0 devices and
the hardware that implements the eXtensible Host Controller Interface
(xHCI) 0.95 specification.  This specification is not yet publicly
available, but companies can receive a copy by becoming an xHCI
Contributor (see http://www.intel.com/technology/usb/xhcispec.htm).

No xHCI hardware has made it onto the market yet, but these patches have
been tested under the Fresco Logic host controller prototype.

This patch adds the xHCI register sets, which are grouped into five sets:
 - Generic PCI registers
 - Host controller "capabilities" registers (cap_regs) short
 - Host controller "operational" registers (op_regs)
 - Host controller "runtime" registers (run_regs)
 - Host controller "doorbell" registers

These some of these registers may be virtualized if the Linux driver is
running under a VM.  Virtualization has not been tested for this patch.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Steve Holland pointed out that we forgot to call break; in the switch
statment.  This probably resolves a lot of the bug reports I've gotten
for the driver lately.

Stupid me...
Reported-by: NSteve Holland <sdh4@iastate.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

In tests 11 and 12 if the URB completes with an error status (eg babble)
the asynchrous unlink entered an endless loop trying to unlink
a non resubmitted URB.
Signed-off-by: NMartin Fuzzey <mfuzzey@gmail.com>
Acked-by: NDavid Brownell <david-b@pacbell.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The toggle_bias() function was specified differently for avr32 and at91
architectures. Now, new at91 have the same behavior as avr32.
Consequently, we change to a particular chip function definition: only for
at91sam9rl.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>