Andrew Waterman
2e8b02e780
Merge D$ store hits when ECC is enabled
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This avoids pipeline flushes due to subword WAW hazards, as with
consecutive byte stores.
2017-07-28 12:56:36 -07:00
Andrew Waterman
838864870e
Bypass TLB refill signal to halve L2 TLB hit time
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The 4-cycle hit time is 1 cycle too long to avoid a second
pipeline replay, so it was effectively 9 cycles instead of 4.
2017-07-28 12:56:36 -07:00
Andrew Waterman
ae1f7a95f6
Don't nack misses when there's a pending store
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That effectively increased the miss latency by 5 cycles when there was
a store hit followed by a load miss. Since pending stores are drained
when releaseInFlight, the check I removed was redundant.
2017-07-28 12:56:36 -07:00
Andrew Waterman
66d06460fa
Add option for acquire-before-release
2017-07-25 15:19:16 -07:00
Henry Cook
4c595d175c
Refactor package hierarchy and remove legacy bus protocol implementations ( #845 )
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* Refactors package hierarchy.
Additionally:
- Removes legacy ground tests and configs
- Removes legacy bus protocol implementations
- Removes NTiles
- Adds devices package
- Adds more functions to util package
2017-07-07 10:48:16 -07:00
Andrew Waterman
be4eceec0d
Fix stupid D$ probe bug
2017-07-06 01:20:47 -07:00
Andrew Waterman
90a7d6a343
Add L2 TLB option
2017-07-06 01:19:18 -07:00
Andrew Waterman
0ef45fac9b
Add tag ECC to D$
2017-07-03 18:16:37 -07:00
Andrew Waterman
e9752f76ae
Improve probe state machine
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- Reduce reliance on s2_prb_ack_data due to future ECC changes
- Shave a cycle off valid, but clean, probes
- Code cleanup
2017-07-03 16:25:04 -07:00
Richard Xia
5b46350bc3
Make sure that DCache s2_xcpt data scratchpad case is assigned to after initial assignment.
2017-06-30 17:44:16 -07:00
Wesley W. Terpstra
ca3030cba3
dcache: fix a gender inversion bug introduced in #826
2017-06-28 15:38:53 -07:00
Andrew Waterman
b9a934ae28
Support eccBytes > 1
2017-06-28 02:09:18 -07:00
Andrew Waterman
6f8fdff762
Basic L1 D$ ECC support
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Only supports ECC on data, not tags; only supports byte granularity.
2017-06-28 02:09:18 -07:00
Andrew Waterman
6100600179
Minor D$ code cleanup
2017-06-28 02:09:18 -07:00
Andrew Waterman
8aa16a11f3
Reduce D$ access energy when refill width > access width
2017-06-28 02:09:18 -07:00
Andrew Waterman
25f585f2a9
Remove unused signal from TLB interface
2017-06-28 02:09:18 -07:00
Henry Cook
6b79842e66
dcache: just left shift by untagbits to get tag
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Always safe because of the requirement on coreplex/RocketTiles.scala:126
2017-06-20 16:35:28 -07:00
Wesley W. Terpstra
80c63c0da6
rocket: include hartid in cache master names
2017-06-02 15:52:23 -07:00
Andrew Waterman
dbc5e7c494
Add TLB miss performance counters ( #762 )
2017-05-23 12:52:25 -07:00
Andrew Waterman
b2b4c1abcd
Separate tag ECC and data ECC options ( #761 )
2017-05-23 12:51:48 -07:00
Andrew Waterman
3a1a37d41b
Support PutPartial in ScratchpadSlavePort
2017-05-02 03:07:02 -07:00
Andrew Waterman
f8151ce786
Remove subword load muxing in ScratchpadSlavePort
2017-05-02 00:14:46 -07:00
Andrew Waterman
8fd5ecdff8
Set io.cpu.resp.bits.addr for MMIO loads without affecting QoR
2017-04-27 19:50:38 -07:00
Andrew Waterman
80d826b94a
Make DTIM deduplicatable
2017-04-26 19:35:35 -07:00
Wesley W. Terpstra
f3ab23d068
dcache: fix stupidly wrong crossing comparison ( #703 )
2017-04-25 09:18:41 -07:00
Wesley W. Terpstra
4807ce7ced
dcache: put a flow Q to absorb back-pressure without restarting pipeline ( #701 )
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* dcache: put a flow Q to absorb back-pressure without restarting pipeline
When used with a RationalCrossing, pipelined MMIO does not come out cleanly.
The first beat works, but if the second beat gets stalled, the pipeline is
restarted. This is a quick hacky test to absorb the beats. Perhaps a better
fix can be made to achieve the same effect.
* dcache: provision as few stages as possible
2017-04-24 23:28:04 -07:00
Andrew Waterman
d82a0dc231
Mitigate D$ exception critical path, yet again
2017-04-18 00:47:58 -07:00
Andrew Waterman
c99ce7ce5d
Only report D$ exceptions on not-nacked accesses
2017-04-18 00:47:58 -07:00
Andrew Waterman
6de6f38894
Pipeline D$ exception response into s2
2017-04-18 00:47:58 -07:00
Andrew Waterman
cc9ec1d51a
Send D$ grant acks early; accept release acks early
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We now need to block the B-channel for a few cycles after a grant to
allow the processor to get at least one request through, preventing
livelock.
2017-04-18 00:47:58 -07:00
Andrew Waterman
c366007a0d
Tighten PMAs for LR/SC and misaligned accesses
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- 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
7871ec82c4
Guarantee probe forward progress during LR storm
2017-04-18 00:47:58 -07:00
Andrew Waterman
d203c4c654
Check AMO operation legality in TLB
2017-04-14 01:03:11 -07:00
Andrew Waterman
2720095b8e
Give D$ RAMs consistent names
2017-03-30 15:49:14 -07:00
solomatnikov
0b9fc94421
Assertion for back-to-back uncached and cached ops ( #631 )
2017-03-29 23:07:17 -07:00
Andrew Waterman
44fb3be7d0
Fix MMIO/cache refill concurrency bug in DCache
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There's a structural hazard on s2_req, so disallow cache refill initiation
while any MMIO loads are in flight.
2017-03-28 17:16:29 -07:00
Andrew Waterman
069858a20c
rocket: separate page faults from physical memory access exceptions
2017-03-27 16:37:09 -07:00
Wesley W. Terpstra
75eba294ec
DCache: Release from the correct ID as well
2017-03-27 16:30:46 -07:00
Wesley W. Terpstra
4959771c97
Revert "For D$, use source 0 through N-1 for MMIO, not 1 through N"
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This reverts commit 0538dc77ce8c0d017d8168298c4dcb99034977b7.
2017-03-27 16:30:46 -07:00
Wesley W. Terpstra
fa7ead6357
Revert "Use Reg(Vec) instead of Seq(Reg) for DCache MMIO"
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This reverts commit fb6498f2c30fc9fa13756e025e44dbca53108af7.
2017-03-27 16:30:46 -07:00
Andrew Waterman
30415215b8
Don't check for exceptions on ScratchpadSlavePort accesses
2017-03-24 16:39:52 -07:00
Andrew Waterman
e9cadf29d2
Improve DCache MMIO QoR
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No need to store the cmd field. From the perspective of the cache, all
MMIO responses that have data can be treated the same as loads.
2017-03-24 16:39:52 -07:00
Andrew Waterman
fb6498f2c3
Use Reg(Vec) instead of Seq(Reg) for DCache MMIO
2017-03-24 16:39:52 -07:00
Andrew Waterman
0538dc77ce
For D$, use source 0 through N-1 for MMIO, not 1 through N
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This makes the code a bit cleaner.
2017-03-24 16:39:52 -07:00
Andrew Waterman
1875407316
Get TLB permission checks off D$ clock gating critical path
2017-03-24 16:39:52 -07:00
Andrew Waterman
487b8db5ef
Address some PMP critical paths
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
cf168e419b
Support SFENCE.VMA rs1 argument
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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
3609254e4a
There's no structural hazard on MMIO store responses
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So don't stall as though there were.
2017-03-21 14:17:32 -07:00
Yunsup Lee
5eae7e1da4
make DCache s1_nack less conservative for pipelined MMIO requests
2017-03-21 11:16:51 -07:00