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Commit Graph

28 Commits

Author SHA1 Message Date
Andrew Waterman
c366007a0d Tighten PMAs for LR/SC and misaligned accesses
- LR/SC on cacheable memory only (not even scratchpad)
- No misaligned accesses on regions with get/put-effects
2017-04-18 00:47:58 -07:00
Andrew Waterman
fdfcffb0b2 Catch bad physical address MSBs when VA size > PA size 2017-04-14 01:03:11 -07:00
Andrew Waterman
d203c4c654 Check AMO operation legality in TLB 2017-04-14 01:03:11 -07:00
Andrew Waterman
8f73a58d90 Report access exception, not page fault, if page-table walk fails 2017-03-30 00:36:23 -07:00
Andrew Waterman
05cbdced78 Work around zero-entry vec issue in Chisel 2017-03-27 17:57:26 -07:00
Andrew Waterman
069858a20c rocket: separate page faults from physical memory access exceptions 2017-03-27 16:37:09 -07:00
Andrew Waterman
97006ab396 Don't modulate PMP privilege on passsthrough when !usingVM 2017-03-24 16:39:52 -07:00
Andrew Waterman
3951e57789 Force each TLB entry into its own clock-gate group
This ameliorates a PMP critical path.

I can't figure out how to do this without asUInt/asTypeOf.
2017-03-24 16:39:52 -07:00
Andrew Waterman
d3bda9574c Put page homogeneity checker in PMP
Avoids redundancy between ITLB and DTLB
2017-03-24 16:39:52 -07:00
Andrew Waterman
86d84959cf More WIP on PMP 2017-03-24 16:39:52 -07:00
Andrew Waterman
0380aed329 PUM -> SUM 2017-03-24 16:39:52 -07:00
Andrew Waterman
723352c3e2 Mitigate some more PMP critical paths 2017-03-24 16:39:52 -07:00
Andrew Waterman
03fb334c4c Take mprv calculation off critical path 2017-03-24 16:39:52 -07:00
Andrew Waterman
f0796f0509 Pass correct access size information to PMP checker 2017-03-24 16:39:52 -07:00
Andrew Waterman
a6874c03f7 Remove DecoupledTLB 2017-03-24 16:39:52 -07:00
Andrew Waterman
78f9f6b9ef When SFENCE.VMA has rs2 != x0, don't flush global mappings 2017-03-24 16:39:52 -07:00
Andrew Waterman
1b950128e1 PTW should always use S-mode privilege
If an exception occurs while a page-table walk is coincidentally in
progress (e.g., an illegal instruction executes during data TLB refill),
then the processor might enter M-mode.  However, the PTW's accesses
should proceed without M privilege, to avoid bypassing PMPs.

Note, the same argument doesn't apply to the nonblocking cache's replay
queues, because those accesses have already been checked against the PMPs.
The cache correctly ignores access exceptions reported on replays,
provided no exceptions were reported on the initial access.
2017-03-24 16:39:52 -07:00
Andrew Waterman
aace526857 WIP on PMP 2017-03-24 16:39:52 -07:00
Andrew Waterman
b1b405404d Set PRV=M when entering debug mode
Debug mode mostly behaves like M-mode, so this approach avoids having
to check the debug bit in most permission checks.
2017-03-24 16:39:52 -07:00
Andrew Waterman
cf168e419b Support SFENCE.VMA rs1 argument
This one's a little invasive.  To flush a specific entry from the TLB, you
need to reuse its CAM port.  Since the TLB lookup can be on the critical
path, we wish to avoid muxing in another address.

This is simple on the data side, where the datapath already carries rs1 to
the TLB (it's the same path as the AMO address calculation).  It's trickier
for the I$, where the TLB lookup address comes from the fetch stage PC.
The trick is to temporarily redirect the PC to rs1, then redirect the PC
again to the instruction after SFENCE.VMA.
2017-03-24 16:39:52 -07:00
Andrew Waterman
1fea0460ba Support superpage entries in TLB 2017-03-13 14:50:06 -07:00
Andrew Waterman
380c10f7bd Zap conflicting TLB entries, preparing for superpage support
Superpages create the possibility that two entries in the TLB may match.
This corresponds to a software bug, but we can't return complete garbage;
we must return either the old translation or the new translation.  This
isn't compatible with the Mux1H approach.  So, flush the TLB and report
a miss on duplicate entries.
2017-03-10 15:58:23 -08:00
Andrew Waterman
db0a02b78e WIP on priv-1.10 2017-03-09 11:29:51 -08:00
Henry Cook
e8c8d2af71 Heterogeneous Tiles (#550)
Fundamental new features:

* Added tile package: This package is intended to hold components re-usable across different types of tile. Will be the future location of TL2-RoCC accelerators and new diplomatic versions of intra-tile interfaces.
* Adopted [ModuleName]Params convention: Code base was very inconsistent about what to name case classes that provide parameters to modules. Settled on calling them [ModuleName]Params to distinguish them from config.Parameters and config.Config. So far applied mostly only to case classes defined within rocket and tile.
* Defined RocketTileParams: A nested case class containing case classes for all the components of a tile (L1 caches and core). Allows all such parameters to vary per-tile.
* Defined RocketCoreParams: All the parameters that can be varied per-core.
* Defined L1CacheParams: A trait defining the parameters common to L1 caches, made concrete in different derived case classes.
* Defined RocketTilesKey: A sequence of RocketTileParams, one for every tile to be created.
* Provided HeterogeneousDualCoreConfig: An example of making a heterogeneous chip with two cores, one big and one little.
* Changes to legacy code: ReplacementPolicy moved to package util. L1Metadata moved to package tile. Legacy L2 cache agent removed because it can no longer share the metadata array implementation with the L1. Legacy GroundTests on life support.

Additional changes that got rolled in along the way:

* rocket: 	Fix critical path through BTB for I$ index bits > pgIdxBits
* coreplex: tiles connected via :=*
* groundtest: updated to use TileParams
* tilelink: cache cork requirements are relaxed to allow more cacheless masters
2017-02-09 13:59:09 -08:00
Wesley W. Terpstra
5d70265e86 rocket: L1 only needs cache-line transfer sizes 2017-01-19 19:07:14 -08:00
Wesley W. Terpstra
bf7823f1c8 tilelink2: split suportsAcquire into T and B variants 2017-01-19 19:07:13 -08:00
Henry Cook
74b6a8d02b Refactor Tile to use cake pattern (#502)
* [rocket] Refactor Tile into cake pattern with traits
* [rocket] cacheDataBits &etc in HasCoreParameters
* [rocket] pass TLEdgeOut implicitly rather than relying on val edge in HasCoreParameters
* [rocket] frontend and icache now diplomatic
* [rocket] file name capitalization
* [rocket] re-add hook for inserting externally-defined Cores
* [rocket] add FPUCoreIO
* [groundtest] move TL1 Config instances to where they are used
* [unittest] remove legacy unit tests
* [groundtest] remove legacy device tests
2017-01-16 18:24:08 -08:00
Henry Cook
540502f96d Convert frontend and icache to diplomacy/tl2 (#486)
* [rocket] file capitalization

* [rocket] cacheDataBits &etc in HasCoreParameters

* [rocket] pass TLEdgeOut implicitly rather than relying on val edge in HasCoreParameters

* [rocket] frontend and icache now diplomatic
2016-12-12 17:38:55 -08:00