d71076d41c
This patch fixes the AArch32-AArch64 interprocessing issue introduced in
3d15150d cpu, arch, arch-arm: Wire unused VecElem code in the O3 model.
When O3CPU switches vector renaming mode, architectural-physical mapping
and physical free list are switched in the following way so that content
of vectors has no change from software view:
Case 1. Full mode -> Elem mode (AArch64 -> AArch32):
1.1. Split vector-vector mapping into element-element mapping.
1.2. Split vectors in free list into elements.
Case 2. Elem mode -> Full mode (AArch32 -> AArch64):
2.1. Move content of all N*M mapped physical elements to first N*M
physical elements in architectural order (N = number of
architectural vectors, M = number of elements per vector).
2.2. Map N architectural vectors to first N physical vectors (i.e.
initial mapping in full mode).
2.3. Place remaining physical vectors in free list (i.e. initial free
list in full mode).
Previous gem5 revision misses step 2.2 when AArch32->AArch64 switch.
The wrong mapping will lead to the situation in which a physical vector
is assigned twice to a same architectural vector without being freed.
Once this occurs, the physical vector will not be freed anymore, since
it is treated as a special register (e.g. zero or misc) by O3CPU's
renaming logic. Eventually O3CPU will either stall forever when all
physical vectors get stuck, or trigger the panic condition "The free
list has lost vector registers" when AArch64->AArch32 switch. This patch
adds the missing step and fixes the issue.
Change-Id: I32233635c28763260bcbb776b52ed198a9abace9
Signed-off-by: Hsuan Hsu <hsuan.hsu@mediatek.com>
Signed-off-by: Howard Wang <Howard.Wang@mediatek.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25743
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
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, SWIG, 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 the aforementioned tools. Once you have all dependencies resolved, type 'scons build/<ARCH>/gem5.opt' where ARCH is one of ARM, NULL, MIPS, POWER, SPARC, or X86. This will build an optimized version of the gem5 binary (gem5.opt) for the the specified architecture. See http://www.gem5.org/documentation/general_docs/building for more details and options. The basic source release includes these subdirectories: - configs: example simulation configuration scripts - ext: less-common external packages needed to build gem5 - 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 will need compiled system firmware (console and PALcode for Alpha), kernel binaries and one or more disk images. If you have questions, please send mail to gem5-users@gem5.org Enjoy using gem5 and please share your modifications and extensions.