Commit Graph

6 Commits

Author SHA1 Message Date
Chris Metcalf 6ec006ede5 tilegx: provide kernel support for the tilegx UART shim
The TILE-Gx chip includes an on-chip UART.  This change adds support
for using the UART from within the kernel.  The UART shim has more
functionality than is exposed here, but to keep the kernel code and
binary simpler, this is a subset of the full API designed to enable
a standard Linux tty serial driver only.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-09-03 14:50:36 -04:00
Chris Metcalf d1cc1732cc arch/tile: provide kernel support for the tilegx USB shim
This change adds support for accessing the USB shim from within the
kernel.  Note that this change by itself does not allow the kernel
to act as a host or as a device; it merely exposes the built-in on-chip
hardware to the kernel.

The <arch/usb_host.h> and <arch/usb_host_def.h> headers are empty at
the moment because the kernel does not require any types or definitions
specific to the tilegx USB shim; the generic USB core code is all we need.
The headers are left in as stubs so that we don't need to modify the
hypervisor header (drv_usb_host_intf.h) from upstream.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-07-18 16:40:24 -04:00
Chris Metcalf bce5bbbb23 arch/tile: provide kernel support for the tilegx TRIO shim
Provide kernel support for the tilegx "Transaction I/O" (TRIO) on-chip
hardware.  This hardware implements the PCIe interface for tilegx;
the driver changes to use TRIO for PCIe are in a subsequent commit.

The change is layered on top of the tilegx GXIO IORPC subsystem.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-07-11 16:04:58 -04:00
Chris Metcalf 4875f69fec arch/tile: provide kernel support for the tilegx mPIPE shim
The TILE-Gx chip includes a packet-processing network engine called
mPIPE ("Multicore Programmable Intelligent Packet Engine").  This
change adds support for using the mPIPE engine from within the
kernel.  The engine has more functionality than is exposed here,
but to keep the kernel code and binary simpler, this is a subset
of the full API designed to enable standard Linux networking only.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-07-11 16:04:55 -04:00
Chris Metcalf 6369798037 arch/tile: common DMA code for the GXIO IORPC subsystem
The dma_queue support is used by both the mPipe (networking)
and Trio (PCI) hardware shims on tilegx.  This common code is
selected when either of those drivers is built.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-07-11 16:04:54 -04:00
Chris Metcalf 37b82b5de7 arch/tile: introduce GXIO IORPC framework for tilegx
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>
2012-07-11 16:04:52 -04:00