[xhci] Do not release ownership back to BIOS when booting an OS
xHCI (and EHCI) nominally provide a mechanism for releasing ownership
of the host controller back to the BIOS, which can then potentially
restore legacy USB keyboard functionality.
This is a rarely used code path, since most operating systems claim
ownership and never attempt to later return to the BIOS. On some
systems (observed with a Lenovo X1 Carbon), this code path leads to
obscure and interesting bugs: if the xHCI and EHCI controllers are
both claimed and later released back to the BIOS, then a subsequent
call to INT 16,0305 to set the keyboard repeat rate to a non-default
value will lock the system.
Obscure though this sequence of operations may sound, it is exactly
what happens when using iPXE to boot a Linux kernel via a USB network
card. There is old and probably unwanted code in Linux's
arch/x86/boot/main.c which sets the keyboard repeat rate (with the
accompanying comment "Set keyboard repeat rate (why?)"). When booting
Linux via a USB network card on a Lenovo X1 Carbon, the system
therefore locks up immediately after jumping to the kernel's entry
point.
Work around this problem by preventing the release of ownership back
to the BIOS if it is known that we are shutting down to boot an OS.
This should allow legacy USB keyboard functionality to be restored if
the user chooses to exit iPXE, while avoiding the rarely used code
paths (and corresponding BIOS bugs) if the user chooses instead to
boot an OS.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Forcibly disable SMIs if BIOS fails to release ownership
If the BIOS fails to gracefully release ownership of the xHCI
controller, we can forcibly claim it by disabling all SMIs via the
USB legacy support control/status register.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[smsc75xx] Move RX FIFO overflow message to DBGLVL_EXTRA
RX FIFO overflow is almost inevitable since the (usable) USB2 bus
bandwidth is approximately one quarter of the Ethernet bandwidth.
Avoid flooding the console with RX FIFO overflow messages in a
standard debug build.
With TCP SACK implemented, the RX FIFO overflow no longer causes a
catastrophic drop in throughput. Experimentation shows that HTTP
downloads now progress at a fairly smooth 250Mbps, which is around the
maximum speed attainable for a USB2 NIC.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[smsc75xx] Add driver for SMSC/Microchip LAN75xx USB Ethernet NICs
This driver is functional but any downloads via a TCP-based protocol
tend to perform poorly. The 1Gbps Ethernet line rate is substantially
higher than the 480Mbps (in practice around 280Mbps) provided by USB2,
and the device has only 32kB of internal buffer memory. Our 256kB TCP
receive window therefore rapidly overflows the RX FIFO, leading to
multiple dropped packets (usually within the same TCP window) and
hence a low overall throughput.
Reducing the TCP window size so that the RX FIFO does not overflow
greatly increases throughput, but is not a general-purpose solution.
Further investigation is required to determine how other OSes
(e.g. Linux) cope with this scenario. It is possible that
implementing TCP SACK would provide some benefit.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Most devices expose at least the link up/down status via a bit in a
MAC register, since the MAC generally already needs to know whether or
not the link is up. Some devices (e.g. the SMSC75xx USB NIC) expose
this information to software only via the MII registers.
Provide a generic mii_check_link() implementation to check the BMSR
and report the link status via netdev_link_{up,down}().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xen] Set the "feature-rx-notify" flag for netfront devices
iPXE already sends RX notifications to the backend when needed, but
does not set the "feature-rx-notify" flag. As of XenServer 6.5, this
flag is mandatory and omitting it will cause the backend to fail.
Fix by setting the "feature-rx-notify" flag, to inform the backend
that we will send notifications.
Reported-by: Shalom Bhooshi <shalom.bhooshi@citrix.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Undo PCH-specific quirk fixes when removing device
Restore the original values of XUSB2PR and USB3PSSEN, in case we are
booting an OS with no support for xHCI.
Suggested-by: Dan Ellis <Dan.Ellis@displaylink.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Enable USB3 ports on Intel PCH8/PCH9 controllers
Intel PCH controllers default to routing USB2 ports to EHCI rather
than xHCI, and default to disabling SuperSpeed connections.
Manipulate the PCI configuration space registers as necessary to
reroute ports and enable SuperSpeed.
Originally-fixed-by: Dan Ellis <Dan.Ellis@displaylink.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[legal] Relicense files under GPL2_OR_LATER_OR_UBDL
Relicense files with kind permission from
Stefan Hajnoczi <stefanha@redhat.com>
alongside the contributors who have already granted such relicensing
permission.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
At some point in the past few years, binutils became more aggressive
at removing unused symbols. To function as a symbol requirement, a
relocation record must now be in a section marked with @progbits and
must not be in a section which gets discarded during the link (either
via --gc-sections or via /DISCARD/).
Update REQUIRE_SYMBOL() to generate relocation records meeting these
criteria. To minimise the impact upon the final binary size, we use
existing symbols (specified via the REQUIRING_SYMBOL() macro) as the
relocation targets where possible. We use R_386_NONE or R_X86_64_NONE
relocation types to prevent any actual unwanted relocation taking
place. Where no suitable symbol exists for REQUIRING_SYMBOL() (such
as in config.c), the macro PROVIDE_REQUIRING_SYMBOL() can be used to
generate a one-byte-long symbol to act as the relocation target.
If there are versions of binutils for which this approach fails, then
the fallback will probably involve killing off REQUEST_SYMBOL(),
redefining REQUIRE_SYMBOL() to use the current definition of
REQUEST_SYMBOL(), and postprocessing the linked ELF file with
something along the lines of "nm -u | wc -l" to check that there are
no undefined symbols remaining.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[legal] Relicense files under GPL2_OR_LATER_OR_UBDL
These files cannot be automatically relicensed by util/relicense.pl
since they either contain unusual but trivial contributions (such as
the addition of __nonnull function attributes), or contain lines
dating back to the initial git revision (and so require manual
knowledge of the code's origin).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[legal] Include full licence text for all GPL2_OR_LATER files
Add the standard warranty disclaimer and Free Software Foundation
address paragraphs to the licence text where these are not currently
present.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When a command times out, abort it (via the Command Abort bit in the
Command Ring Control Register) so that subsequent commands may execute
as expected.
This improves robustness when a device fails to respond to the Set
Address command, since the subsequent Disable Slot command will now
succeed.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Leak memory if controller fails to disable slot
If the Disable Slot command fails then the hardware may continue to
write to the slot context. Leak the memory used by the slot context
to avoid future memory corruption.
This situation has been observed in practice when a Set Address
command fails, causing the command ring to become temporarily
unresponsive.
Note that there is no need to similarly leak memory on the failure
path in xhci_device_open(), since in the event of a failure the
hardware is never informed of the slot context address.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[usb] Provide generic framework for refilling receive endpoints
Provide a generic framework for allocating, refilling, and optionally
recycling I/O buffers used by bulk IN and interrupt endpoints.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[usb] Handle port status changes received after failing to find a driver
Commit a60f2dd ("[usb] Try multiple USB device configurations")
changed the behaviour of register_usb() such that if no drivers are
found then the device will be closed and the memory used will be
freed.
If a port status change subsequently occurs while the device is still
physically attached, then usb_hotplug() will see this as a new device
having been attached, since there is no device recorded as being
currently attached to the port. This can lead to spurious hotplug
events (or even endless loops of hotplug events, if the process of
opening and closing the device happens to generate a port status
change).
Fix by using a separate flag to indicate that a device is physically
attached (even if we have no corresponding struct usb_device).
Reported-by: Dan Ellis <Dan.Ellis@displaylink.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Delay after (possibly) forcing port link state to RxDetect
Some xHCI controllers (observed with a Renesas Electronics PCIe USB3
card) seem to require a delay after forcing the link state of USB3
ports to RxDetect. Omitting this delay causes strange behaviour
including system lockups.
Add an unconditional 20ms delay after writing the port link states.
This seems to be sufficient to avoid the problem.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[usb] Allow usb_stream() to enforce a terminating short packet
Some USB endpoints require that a short packet be used to terminate
transfers, since they have no other way to determine message
boundaries. If the message length happens to be an exact multiple of
the USB packet size, then this requires the use of an additional
zero-length packet.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
USB Communications Device Class devices may use a union functional
descriptor to group several interfaces into a function.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Iterate over a USB device's available configurations until we find one
for which we have working drivers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some protocols (such as ARP) may modify the received packet and re-use
the same I/O buffer for transmission of a reply. To allow this,
reserve sufficient headroom at the start of each received packet
buffer for our transmit datapath headers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some devices have a very small number of internal buffers, and rely on
being able to pack multiple packets into each buffer. Using 2048-byte
buffers on such devices produces throughput of around 100Mbps. Using
a small number of much larger buffers (e.g. 32kB) increases the
throughput to around 780Mbps. (The full 1Gbps is not reached because
the high RTT induced by the use of multi-packet buffers causes us to
saturate our 256kB TCP window.)
Since allocation of large buffers is very likely to fail, allocate the
buffer set only once when the device is opened and recycle buffers
immediately after use. Received data is now always copied to
per-packet buffers.
If allocation of large buffers fails, fall back to allocating a larger
number of smaller buffers. This will give reduced performance, but
the device will at least still be functional.
Share code between the interrupt and bulk IN endpoint handlers, since
the buffer handling is now very similar.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow drivers to specify a supported PCI class code. To save space in
the final binary, make this an attribute of the driver rather than an
attribute of a PCI device ID list entry.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[hyperv] Assume that VMBus xfer page ranges correspond to RNDIS messages
The (undocumented) VMBus protocol seems to allow for transfer
page-based packets where the data payload is split into an arbitrary
set of ranges within the transfer page set.
The RNDIS protocol includes a length field within the header of each
message, and it is known from observation that multiple RNDIS messages
can be concatenated into a single VMBus message.
iPXE currently assumes that the transfer page range boundaries are
entirely arbitrary, and uses the RNDIS header length to determine the
RNDIS message boundaries.
Windows Server 2012 R2 generates an RNDIS_INDICATE_STATUS_MSG for an
undocumented and unknown status code (0x40020006) with a malformed
RNDIS header length: the length does not cover the StatusBuffer
portion of the message. This causes iPXE to report a malformed RNDIS
message and to discard any further RNDIS messages within the same
VMBus message.
The Linux Hyper-V driver assumes that the transfer page range
boundaries correspond to RNDIS message boundaries, and so does not
notice the malformed length field in the RNDIS header.
Match the behaviour of the Linux Hyper-V driver: assume that the
transfer page range boundaries correspond to the RNDIS message
boundaries and ignore the RNDIS header length. This avoids triggering
the "malformed packet" error and also avoids unnecessary data copying:
since we now have one I/O buffer per RNDIS message, there is no longer
any need to use iob_split().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Empirical observation suggests that 32 is a sensible size to minimise
the number of deferred packet transmissions without overflowing the
VMBus transmit ring buffer.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown