diff options
| author | Giacomo Gabrielli <Giacomo.Gabrielli@arm.com> | 2011-02-11 18:29:35 -0600 |
|---|---|---|
| committer | Giacomo Gabrielli <Giacomo.Gabrielli@arm.com> | 2011-02-11 18:29:35 -0600 |
| commit | e2507407b17188dca802082434cfe0230d9bfa61 (patch) | |
| tree | 6913f9325a7c2fc9c6e99119c61f014e10707842 /src/sim | |
| parent | 453dbc772dba92dbceb44eaeef3c617d17d63e84 (diff) | |
| download | gem5-e2507407b17188dca802082434cfe0230d9bfa61.tar.xz | |
O3: Enhance data address translation by supporting hardware page table walkers.
Some ISAs (like ARM) relies on hardware page table walkers. For those ISAs,
when a TLB miss occurs, initiateTranslation() can return with NoFault but with
the translation unfinished.
Instructions experiencing a delayed translation due to a hardware page table
walk are deferred until the translation completes and kept into the IQ. In
order to keep track of them, the IQ has been augmented with a queue of the
outstanding delayed memory instructions. When their translation completes,
instructions are re-executed (only their initiateAccess() was already
executed; their DTB translation is now skipped). The IEW stage has been
modified to support such a 2-pass execution.
Diffstat (limited to 'src/sim')
| -rw-r--r-- | src/sim/tlb.hh | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/src/sim/tlb.hh b/src/sim/tlb.hh index 1512bc0fa..253f12072 100644 --- a/src/sim/tlb.hh +++ b/src/sim/tlb.hh @@ -1,4 +1,16 @@ /* + * Copyright (c) 2011 ARM Limited + * All rights reserved. + * + * The license below extends only to copyright in the software and shall + * not be construed as granting a license to any other intellectual + * property including but not limited to intellectual property relating + * to a hardware implementation of the functionality of the software + * licensed hereunder. You may use the software subject to the license + * terms below provided that you ensure that this notice is replicated + * unmodified and in its entirety in all distributions of the software, + * modified or unmodified, in source code or in binary form. + * * Copyright (c) 2006 The Regents of The University of Michigan * All rights reserved. * @@ -64,6 +76,12 @@ class BaseTLB : public SimObject virtual ~Translation() {} + /** + * Signal that the translation has been delayed due to a hw page table + * walk. + */ + virtual void markDelayed() = 0; + /* * The memory for this object may be dynamically allocated, and it may * be responsible for cleaning itself up which will happen in this |