Each event segment has been exposed through debugfs. There is no
need to dump ERST content with printk in code. Remove it to make
code more concise and readable.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The content of each register has been exposed through debugfs.
There is no need to dump register content with printk in code
lines. Remove them to make code more concise and readable.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be removed as it is no longer needed at all.
This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.
No copyright headers or other non-license-description text was removed.
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.
Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.
This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
XHCI context changes have already been traced by the trace
events. It's unnecessary to put the same message in kernel
log. This patch removes the use of xhci_dbg_ctx().
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Every XHCI TRB has already been traced by the trb trace events.
It is unnecessary to put the same message in kernel log. This
patch removes xhci_debug_trb().
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
XHCI ring changes have already been traced by the ring trace
events. It's unnecessary to put the same messages in kernel
log. This patch removes the debugging code for a ring.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
enq_updates and deq_updates were introduced in the first place
to check whether an xhci hardware is able to respond to trbs
enqueued in the ring. We now have trb tracers to trace every
single enqueue/dequeue trb. It's time to remove them and the
associated debugging code.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xhci_dbg_ep_rings() isn't used in xhci driver anymore. Remove
it to reduce the module binary size.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
By extracting and exposing xhci_slot_state_string() in a header file, we
can re-use it to print Slot Context State from our tracepoints, which
can aid in tracking down problems related to command execution.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
According to xHCI spec, HCIVERSION containing a BCD encoding
of the xHCI specification revision number, 0100h corresponds
to xHCI version 1.0. Change "100" as "0x100".
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Fixes: 04abb6de28 ("xhci: Read and parse new xhci
1.1 capability register")
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When calling xhci_dbg_regs() we actually _do_ want to know XHCI's
version. This might help figure out why certain problems only happen
in some cases.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is a cleanup patch only, no functional changes. The idea is just to
make sure for loops look the same all over the driver.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xhci 1.1 capable controllers have a new HCCPARAMS2 registers
with bits indicating support for new xhci 1.1 capabilities.
Also add support for the new xhci 1.1 bits in the config operational
opertational register that used to be reserved
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
[modified and left out parts not related to HCCPARAMS2 -Mathias]
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch enables xhci driver to support SPC by handling
Stopped - Short Packet event in transfer event path.
If SPC = '1' and the stop endpoint command is executed, after a Short
Packet condition has been detected, but before the end of the TD has been
reached, (i.e. the TD is in progress for pipe), then a Transfer Event TRB
with its Completion Code set to Stopped - Short Packet and its TRB
Transfer Length set to value of the EDTLA shall be forced for the
interrupted TRB, irrespective of whether its IOC or ISP flags are set.
This Transfer Event TRB will precede the Command Completion Event TRB for
the command, and is referred to as a Stopped Transfer Event.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the Contiguous Frame ID Capability is supported (CFC = 1),
then the xHC shall match the Frame ID in every Isoch TD with
SIA = 0 against the Frame Index of the MFINDEX register. This
rule ensures resynchronization of Isoch TDs even if some are
dropped due to Missed Service Errors or Stopping the endpoint.
This patch enables xHCI driver to support CFC by calculating
and setting the Frame ID field of an Isoch TRB.
[made some dbg messages checkpatch friendly -Mathias]
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some parameters are not used by functions in xhci-mem.c, just
remove it.
Changes compared to v1:
- Rebase to the latest usb-next branch
Signed-off-by: Lin Wang <lin.x.wang@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation for allowing the xHCI host controller drivers to be built
as separate modules, export symbols from the xHCI core that may be used
by the host controller drivers.
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit e8b373326d. Many xHCI
host controllers can only handle 32-bit addresses, and writing 64-bits
at a time causes them to fail. Reading 64-bits at a time may also cause
them to return 0xffffffff, so revert this commit as well.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Function xhci_read_64() is used to read 64bit xHC registers residing in MMIO.
On 32bit systems, xHC registers need to be read with 32bit accesses by
reading first the lower 32bits and then the higher 32bits.
Replace all calls to xhci_read_64() with calls to readq() and include
asm-generic/io-64-nonatomic-lo-hi.h header file, so that if the system
is not 64bit, readq() will read registers in 32bit chunks with low-high order.
This is done to reduce code duplication since 64bit low-high read logic
is already implemented and to take advantage of inherent "atomic" 64bit
read operations on 64bit systems.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Function xhci_readl() is used to read 32bit xHC registers residing in MMIO
address space. It takes as first argument a pointer to the xhci_hcd although
it does not use it. xhci_readl() internally simply calls readl(). This creates
an illusion that xhci_readl() is an xhci specific function that has to be
called in a context where a pointer to xhci_hcd is available.
Remove the unnecessary xhci_readl() wrapper function and replace its calls to
with calls to readl() to make the code more straightforward.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
This patch declares an event class for trace events that
trace messages with variadic arguments, called xhci_log_msg,
and defines a trace event for tracing the debug messages in
xhci_address_device() function, called xhci_dbg_address.
In order to implement this type of trace events, a wrapper function,
called xhci_dbg_trace(), was created that records the format string
and variadic arguments into a va_format structure which is passed as
argument to the tracepoints of the class xhci_log_msg.
All the xhci_dbg() calls in xhci_address_device() are replaced
with calls to xhci_dbg_trace(). The functionality of xhci_dbg()
log messages was not removed though, but it is placed inside
xhci_dbg_trace().
This trace event aims to give the ability to the user or the
developper to isolate and trace the debug messages generated
when an Address Device Command is issued to xHC.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Fail gracefully, instead of causing the kernel to panic, if the input
control context doesn't have the right type (XHCI_CTX_TYPE_INPUT). Push
finding the pointer to the input control context up into functions that
can fail.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: John Youn <johnyoun@synopsys.com>
When CONFIG_XHCI_HCD_DEBUGGING is activated, the XHCI driver can dump
device and input contexts to the console. The endpoint contexts in that
dump are labeled "Endpoint N Context", where N is the XHCI endpoint
index (DCI - 1). This can be very confusing, especially for people who
are not that familiar with the XHCI specification. This patch introduces
an xhci_get_endpoint_address function (as a counterpart to the reverse
xhci_get_endpoint_index), and uses it to additionally display the
endpoint number and direction when dumping contexts, which are much more
commonly used concepts in USB.
Signed-off-by: Julius Werner <jwerner@chromium.org>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Remove the variable slot_ctx from xhci_dbg_ctx(), since it is assigned
but unused. Caught by Coverity.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
This needs to be added to the stable trees back to 2.6.34 to support an
upcoming bug fix.
Signed-off-by: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
Some of the recently-added cpu_to_leXX and leXX_to_cpu made things somewhat
messy; this patch neatens some of these areas, removing unnecessary casts
in those parts also. In some places (where Y & Z are constants) a
comparison of (leXX_to_cpu(X) & Y) == Z has been replaced with
(X & cpu_to_leXX(Y)) == cpu_to_leXX(Z). The endian reversal of the
constants should wash out at compile time.
Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
This patch changes the struct members defining access to xHCI device-visible
memory to use __le32/__le64 where appropriate, and then adds swaps where
required. Checked with sparse that all accesses are correct.
MMIO accesses use readl/writel so already are performed LE, but prototypes
now reflect this with __le*.
There were a couple of (debug) instances of DMA pointers being truncated to
32bits which have been fixed too.
Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Functions that are not used outsde of the module they are defined
should be marked as static.
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
xhci->ir_set points to __iomem region, but xhci_print_ir_set accepts
plain struct xhci_intr_reg * causing multiple sparse warning at call
sites and inside the fucntion when we try to read that memory.
Instead of adding __iomem qualifier to the argument let's rework the
function so it itself gets needed register set from xhci and prints
it.
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
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: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Randy Dunlap reported this error when compiling the xHCI driver:
linux-next-20100104/drivers/usb/host/xhci.h:1214:
sorry, unimplemented: inlining failed in call to 'xhci_get_slot_state': function body not available
The xhci_get_slot_state() function belongs in xhci-dbg.c, since it
involves debugging internal xHCI structures. However, it is only used in
xhci-hcd.c. Some toolchains may have issues since the inlined function
body is not in the xhci.h header file. Remove the inline keyword to avoid
this.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When a USB device is reset, the xHCI hardware must know, in order to match
the device state and disable all endpoints except control endpoint 0.
Issue a Reset Device command after a USB device is successfully reset.
Wait on the command to finish, and then cache or free the disabled
endpoint rings.
There are four different USB device states that the xHCI hardware tracks:
- disabled/enabled - device connection has just been detected,
- default - the device has been reset and has an address of 0,
- addressed - the device has a non-zero address but no configuration has
been set,
- configured - a set configuration succeeded.
The USB core may issue a port reset when a device is in any state, but the
Reset Device command will fail for a 0.96 xHC if the device is not in the
addressed or configured state. Don't consider this failure as an error,
but don't free any endpoint rings if this command fails.
A storage driver may request that the USB device be reset during error
handling, so use GPF_NOIO instead of GPF_KERNEL while allocating memory
for the Reset Device command.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use the virtual address of the memory hardware uses, not the address for
the container of that memory.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Adds support for controllers that use 64-byte contexts. The following context
data structures are affected by this: Device, Input, Input Control, Endpoint,
and Slot. To accommodate the use of either 32 or 64-byte contexts, a Device or
Input context can only be accessed through functions which look-up and return
pointers to their contained contexts.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sure the xHCI output device context is 64-byte aligned. Previous
code was using the same structure for both the output device context and
the input control context. Since the structure had 32 bytes of flags
before the device context, the output device context wouldn't be 64-byte
aligned. Define a new structure to use for the output device context and
clean up the debugging for these two structures.
The copy of the device context in the input control context does *not*
need to be 64-byte aligned.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are several xHCI data structures that use two 32-bit fields to
represent a 64-bit address. Since some architectures don't support 64-bit
PCI writes, the fields need to be written in two 32-bit writes. The xHCI
specification says that if a platform is incapable of generating 64-bit
writes, software must write the low 32-bits first, then the high 32-bits.
Hardware that supports 64-bit addressing will wait for the high 32-bit
write before reading the revised value, and hardware that only supports
32-bit writes will ignore the high 32-bit write.
Previous xHCI code represented 64-bit addresses with two u32 values. This
lead to buggy code that would write the 32-bits in the wrong order, or
forget to write the upper 32-bits. Change the two u32s to one u64 and
create a function call to write all 64-bit addresses in the proper order.
This new function could be modified in the future if all platforms support
64-bit writes.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Without this change the loops won't start
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg 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: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg 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: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Turns out someone never built this code on a 64bit platform.
Someone owes me a beer...
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg 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: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg 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: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg 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: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg 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: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg 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: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
