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The Tile architecture port was added by Chris Metcalf in 2010, and
maintained until early 2018 when he orphaned it due to his departure
from Mellanox, and nobody else stepped up to maintain it. The product
line is still around in the form of the BlueField SoC, but no longer
uses the Tile architecture.
There are also still products for sale with Tile-GX SoCs, notably the
Mikrotik CCR router family. The products all use old (linux-3.3) kernels
with lots of patches and won't be upgraded by their manufacturers. There
have been efforts to port both OpenWRT and Debian to these, but both
projects have stalled and are very unlikely to be continued in the future.
Given that we are reasonably sure that nobody is still using the port
with an upstream kernel any more, it seems better to remove it now while
the port is in a good shape than to let it bitrot for a few years first.
Cc: Chris Metcalf <chris.d.metcalf@gmail.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: http://www.mellanox.com/page/npu_multicore_overview
Link: https://jenkins.debian.net/view/rebootstrap/job/rebootstrap_tilegx_gcc7/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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The GXIO I/O RPC subsystem handles exporting I/O hardware resources to
Linux and to applications running under Linux.
For instance, memory which is made available for I/O DMA must be mapped
by an I/O TLB; that means that such memory must be locked down by Linux,
so that it is not swapped or otherwise reused, as long as those I/O
TLB entries are active. Similarly, configuring direct hardware access
introduces new validation requirements. If a user application registers
memory, Linux must ensure that the supplied virtual addresses are valid,
and turn them into client physical addresses. Similarly, when Linux then
supplies those client physical addresses to the Tilera hypervisor, it
must in turn validate those before turning them into the real physical
addresses which are required by the hardware.
To the extent that these sorts of activities were required on previous
TILE architecture processors, they were implemented in a device-specific
fashion. This meant that every I/O device had its own Tilera hypervisor
driver, its own Linux driver, and in some cases its own user-level
library support. There was a large amount of more-or-less functionally
identical code in different places, particularly in the different Linux
drivers. For TILE-Gx, this support has been generalized into a common
framework, known as the I/O RPC framework or just IORPC.
The two "gxio" directories (one for headers, one for sources) start
with just a few files in each with this infrastructure commit, but
after adding support for the on-board I/O shims for networking, PCI,
USB, crypto, compression, I2CS, etc., there end up being about 20 files
in each directory.
More information on the IORPC framework is in the <hv/iorpc.h> header,
included in this commit.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
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