commit d0c7d235c09fc65dbdb278e7016a96f79c6a49cc
Make the Altera JTAG UART device driver slightly more forgiving of
the foibles of a sub-par hrdware interface by increasing the timeout
for spotting JTAG polling from one to two seconds.
commit 19ed45a18832560dab967c179d83b71081c3a220
Update comment.
commit 8edfe803f033cc8e33229f99894c2b7496a44d5f
Add a comment about a device-driver race condition that could cause the BERI
pipeline to wedge awaiting JTAG in the event that both the low-level console
and the tty layer decide to write to the JTAG FIFO just before JTAG is
disconnected. Resolving this race is a bit tricky as it looks like there
isn't a way to 'give the character back' to the tty layer when we discover
the race. The easy fix is to drop the character, which we don't yet do, but
perhaps should as that is a better outcome than wedging the pipeline.
commit 2ea26cf579c9defcf31e413e7c9b0fbc159237fc
Add a comment about an inherent race with hardware in the Altera JTAG
UART's low-level console code.
Submitted by: rwatson
MFC after: 1 week
Sponsored by: DARPA, AFRL
commit 8bd88585ed8e3f7def0d780a1bc30d96fe642b9c
Rework atse_rx_cycles handling: count packets instead of fills, and use the
limit only when polling, not when in interrupt mode. Otherwise, we may
stop reading the FIFO midpacket and clear the event mask even though the
FIFO still has data to read, which could stall receive when a large packet
arrives. Add a comment about races in the Altera FIFO interface: we may
need to do a little more work to handle races than we are.
commit 20b39086cc612f8874dc9e6ef4c0c2eb777ba92a
Use 'sizeof(data)' rather than '4' when checking an mbuf bound, as is the
case for adjusting length/etc.
commit e18953174a265f40e9ba60d76af7d288927f5382
Break out atse_intr() into two separate routines, one for each of the two
interrupt sources: receive and transmit.
commit 6deedb43246ab3f9f597918361831fbab7fac4ce
For the RX interrupt, take interest only in ALMOSTEMPTY and OVERFLOW.
For the TX interrupt, take interest only in ALMOSTFULL and UNDERFLOW.
Perform TX atse_start_locked() once rather than twice in TX interrupt
handling -- and only if !FULL, rather than unconditionally.
commit 12601972ba08d4380201a74f5b967bdaeb23092c
Experimentation suggests that the Altera Triple-Speed Ethernet documentation
is incorrect and bits in the event and interrupt-enable registers are not
irrationally rearranged relative to the status register.
commit 3cff2ffad769289fce3a728152e7be09405385d8
Substantially rework interrupt handling in the atse(4) driver:
- Introduce a new macro ATSE_TX_PENDING() which checks whether there is
any pending data to transmit, either in an in-progress packet or in
the TX queue.
- Introduce new ATSE_RX_STATUS_READ() and ATSE_TX_STAUTS_WRITE() macros
that query the FIFO status registers rather than event registers,
offering level- rather than edge-triggered FIFO conditions.
- For RX, interrupt only on full/overflow/underflow; for TX, interrupt
only on empty/overflow/underflow.
- Add new ATSE_RX_INTR_READ() and ATSE_RX_INTR_WRITE() macros useful for
debugging interrupt behaviour.
- Add a debug.atse_intr_debug_enable sysctl that causes various pieces
of FIFO state to be printed out on each RX or TX interrupt. This is
disabled by default but good to turn on if the interface appears to
wedge. Also print debugging information when polling.
- In the watchdog handler, do receive, not just transmit, processing, to
ensure that the rx, not just tx, queue is being handled -- and, in
particular, will be drained such that interrupts can resume.
- Rework both atse_rx_intr() and atse_tx_intr() to eliminate many race
conditions, and add comments on why various things are in various
orders. Interactions between modifications to the event and interrupt
masks are quite subtle indeed, and we must actively check for a number
of races (e.g., event mask cleared; packet arrives; interrupts enabled).
We also now use the status registers rather than event registers for
FIFO status checks to avoid other races; we continue to use event
registers for underflow/overflow.
With this change, interrupt-driven operation of atse appears (for the
time being) robust.
commit 3393bbff5c68a4e61699f9b4a62af5d2a5f918f8
atse: Fix build after 3cff2ffa
Obtained from: cheribsd
Submitted by: rwatson, emaste
Sponsored by: DARPA/AFRL
MFC after: 3 days
to check the status property in their probe routines.
Simplebus used to only instantiate its children whose status="okay"
but that was improper behavior, fixed in r261352. Now that it doesn't
check anymore and probes all its children; the children all have to
do the check because really only the children know how to properly
interpret their status property strings.
Right now all existing drivers only understand "okay" versus something-
that's-not-okay, so they all use the new ofw_bus_status_okay() helper.
221804, 221805, 222004, 222006, 222055, 222820, 1135077, 1135118, 1136259
Add atse(4), a driver for the Altera Triple Speed Ethernet MegaCore.
The current driver support gigabit Ethernet speeds only and works with
the MegaCore only in the internal FIFO configuration in the soon to be
open sourced BERI CPU configuration.
Submitted by: bz
MFC after: 3 days
Sponsored by: DARPA/AFRL
Change 231100 by brooks@brooks_zenith on 2013/07/12 21:01:31
Add a new option ALTERA_SDCARD_FAST_SIM which checks immediatly
for success of I/O operations rather than queuing a task.
MFC after: 3 days
Sponsored by: DARPA/AFRL
Change 227594 by brooks@brooks_zenith on 2013/04/11 17:10:14
When we fail, print the error that occured if we are giving
up or if bootverbose is set.
MFC after: 3 days
Sponsored by: DARPA/AFRL
Add a missing 0 to the mask for byte0 of C_SIZE.
The previous mask (0xc) worked except that the last 0-1536K of the disk
could not be accessed since we were shifting the (wrong) bits we did
mask off the right edge.
Implement an FDT attachment for altera_avgen(4).
Portions of the changeset updating DTS and device.hints will be merged
separately.
Sponsored by: DARPA, AFRL
Rework altera_avgen(4) to cleanly(ish) separate nexus bus
attachment from the driver itself. This should allow us to
plug in an fdt attachment more easily.
Sponsored by: DARPA, AFRL
Start restructuring of altera_avgen(4) so that it can have an FDT
attachment -- this requires first properly breaking out the current
nexus attachment from the driver implementation.
Sponsored by: DARPA, AFRL
which presents a UART-like interface over the Avalon bus that can be
addressed over JTAG. This IP core proves extremely useful, allowing us to
connect trivially to the FreeBSD console over JTAG for FPGA-embedded hard
and soft cores. As interrupts are optionally configured for this soft
core, we support both interrupt-driven and polled modes of operation,
which must be selected using device.hints. UART instances appear in /dev
as ttyu0, ttyu1, etc.
However, it also contains a number of quirks, which make it difficult to
tell when JTAG is connected, and some buffering issues. We work around
these as best we can, using various heuristics.
While the majority of this device driver is not only not BERI-specific,
but also not MIPS-specific, for now add its defines in the BERI files
list, as the console-level parts are aware of where the first JTAG UART
is mapped on Avalon, and contain MIPS-specific address translation, to
use before Newbus and device.hints are available.
Sponsored by: DARPA, AFRL
which can be synthesised in Altera FPGAs. An altera_sdcardc device
probes during the boot, and /dev/altera_sdcard devices come and go as
inserted and removed. The device driver attaches directly to the
Nexus, as is common for system-on-chip device drivers.
This IP core suffers a number of significant limitations, including a
lack of interrupt-driven I/O -- we must implement timer-driven polling,
only CSD 0 cards (up to 2G) are supported, there are serious memory
access issues that require the driver to verify writes to memory-mapped
buffers, undocumented alignment requirements, and erroneous error
returns. The driver must therefore work quite hard, despite a fairly
simple hardware-software interface. The IP core also supports at most
one outstanding I/O at a time, so is not a speed demon.
However, with the above workarounds, and subject to performance
problems, it works quite reliably in practice, and we can use it for
read-write mounts of root file systems, etc.
Sponsored by: DARPA, AFRL
CPU cores on Altera FPGAs. The device driver allows memory-mapped devices
on Altera's Avalon SoC bus to be exported to userspace via device nodes.
device.hints directories dictate device name, permissible access methods,
physical address and length, and I/O alignment. Devices can be accessed
using read(2)/write(2), but also memory mapped in userspace using mmap(2).
Devices attach directly to the Nexus, as is common for embedded device
drivers; in the future something more mature might be desirable. There is
currently no facility to support directing device-originated interrupts to
userspace.
In the future, this device driver may be renamed to socgen(4), as it can
in principle also be used with other system-on-chip (SoC) busses, such as
Axi on ASICs and FPGAs. However, we have only tested it on Avalon busses
with memory-mapped ROMs, frame buffers, etc.
Sponsored by: DARPA, AFRL
