578eaead47
The PCI read/write functions are atomic functions in gem5, meaning they
expect a response with a latency value on the same simulation Tick. For
reads to a PCI device, the response must also include a data value read
from the device.
The AMDGPU device has a PCI BAR which mirrors the frame buffer memory.
Currently reads are done atomically, but writes are sent to a DMA device
without waiting for a write completion ACK. As a result, it is possible
that writes can be queued in the DMA device long enough that another
read for a queued address arrives. This happens very deterministically
with the AtomicSimpleCPU and causes GPUFS to break with that CPU.
This change makes writes to the frame BAR atomic the same as reads. This
avoids that problem and as a result the AtomicSimpleCPU can now load the
driver for GPUFS simulations.
Change-Id: I9a8e8b172712c78b667ebcec81a0c5d0060234db
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/71898
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Matthew Poremba <matthew.poremba@amd.com>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
(cherry picked from commit 079fc47dc2)
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/72079
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
This is the gem5 simulator. The main website can be found at http://www.gem5.org A good starting point is http://www.gem5.org/about, and for more information about building the simulator and getting started please see http://www.gem5.org/documentation and http://www.gem5.org/documentation/learning_gem5/introduction. To build gem5, you will need the following software: g++ or clang, Python (gem5 links in the Python interpreter), SCons, zlib, m4, and lastly protobuf if you want trace capture and playback support. Please see http://www.gem5.org/documentation/general_docs/building for more details concerning the minimum versions of these tools. Once you have all dependencies resolved, type 'scons build/<CONFIG>/gem5.opt' where CONFIG is one of the options in build_opts like ARM, NULL, MIPS, POWER, SPARC, X86, Garnet_standalone, etc. This will build an optimized version of the gem5 binary (gem5.opt) with the the specified configuration. See http://www.gem5.org/documentation/general_docs/building for more details and options. The main source tree includes these subdirectories: - build_opts: pre-made default configurations for gem5 - build_tools: tools used internally by gem5's build process. - configs: example simulation configuration scripts - ext: less-common external packages needed to build gem5 - include: include files for use in other programs - site_scons: modular components of the build system - src: source code of the gem5 simulator - system: source for some optional system software for simulated systems - tests: regression tests - util: useful utility programs and files To run full-system simulations, you may need compiled system firmware, kernel binaries and one or more disk images, depending on gem5's configuration and what type of workload you're trying to run. Many of those resources can be downloaded from http://resources.gem5.org, and/or from the git repository here: https://gem5.googlesource.com/public/gem5-resources/ If you have questions, please send mail to gem5-users@gem5.org Enjoy using gem5 and please share your modifications and extensions.