* mem: support ld-ld violation check
* mem: do not fast wakeup if ld vio check failed
* mem: disable ld-ld vio check after core reset

add mmu's asid support.
1. put asid inside sram (if the entry is sram), or it will take too many sources.
2. when sfence, just flush it all, don't care asid.
3. when hit check, check asid.
4. when asid changed, flush all the inflight ptw req for safety
5. simple asid unit test:
asid 1 write, asid 2 read and check, asid 2 write, asid 1 read and check. same va, different pa

* ASID: make satp's asid bits configurable to RW
* use AsidLength to control it

* ASID: implement asid refilling and hit checking
* TODO: sfence flush with asid

* ASID: implement sfence with asid
* TODO: extract asid from SRAMTemplate

* ASID: extract asid from SRAMTemplate
* all is down
* TODO: test

* fix write to asid

* Sfence: support rs2 of sfence and fix Fence Unit
* rs2 of Sfence should be Reg and pass it to Fence Unit
* judge the value of reg instead of the index in Fence Unit

* mmu: re-write asid

now, asid is stored inside sram, so sfence just flush it
it's a complex job to handle the problem that asid is changed but
no sfence.vma is executed. when asid is changed, all the inflight
mmu reqs are flushed but entries in storage is not influenced.
so the inflight reqs do not need to record asid, just use satp.asid

* tlb: fix bug of refill mask

* ci: add asid unit test
Co-authored-by: NZhangZifei <zhangzifei20z@ict.ac.cn>

* Refactor cache params

* L2: support multi-bank

* fix l2 size

* remove 'IgnoreNode'

* bump difftest and huancun

* rename Roq to Rob

* remove trailing whitespaces

* remove unused parameters

This commit adds load balance strategy in issue selection logic for
reservation stations.

Previously we have a load balance option in ExuBlock, but it cannot work
if the function units have feedbacks to RS. In this commit it is
removed.

This commit adds a victim index option for oldestFirst. For LOAD, the
first issue port has better performance and thus we set the victim index
to 0. For other function units, we use the last issue port.

* mmu.l2tlb: add object TimeOutAssert

* mmu.l2tlb: add TimeOutAssert to Repeater

* mmu.l2tlb: cut down mem req buffer from 8 ptes to 1 pte each

* util: move some utils from MMUBundle to utils

This commit adds assertion in MaskData to check the width of mask
and data. When the width of mask is smaller than the width of data,
(~mask & data) and (mask & data) will always clear the upper bits
of the data. This usually causes unexpected behavior.

This commit adds explicit width declarations where MaskData is used.

* Revert "Revert "l0tlb: add a new level tlb to each mem pipeline (#936)" (#945)"

This reverts commit b052b972.

* fu: remove unused import

* mmu.tlb: 2 load/store pipeline has 1 dtlb

* mmu: remove btlb, the l1-tlb

* mmu: set split-tlb to 32 to check perf effect

* mmu: wrap tlb's param with TLBParameters

* mmu: add params 'useBTlb'

dtlb size is small: normal 8, super 2

* mmu.tlb: add Bundle TlbEntry, simplify tlb hit logic(coding)

* mmu.tlb: seperate tlb's storage, relative hit/sfence logic

tlb now supports full-associate, set-associate, directive-associate.
more: change tlb's parameter usage, change util.Random to support
case that mod is 1.

* mmu.tlb: support normalAsVictim, super(fa) -> normal(sa/da)

be carefull to use tlb's parameter, only a part of param combination
is supported

* mmu.tlb: fix bug of hit method and victim write

* mmu.tlb: add tlb storage's perf counter

* mmu.tlb: rewrite replace part, support set or non-set

* mmu.tlb: add param outReplace to receive out replace index

* mmu.tlb: change param superSize to superNWays

add param superNSets, which should always be 1

* mmu.tlb: change some perf counter's name and change some params

* mmu.tlb: fix bug of replace io bundle

* mmu.tlb: remove unused signal wayIdx in tlbstorageio

* mmu.tlb: separate tlb_ld/st into two 'same' tlb

* mmu.tlb: when nWays is 1, replace returns 0.U

before, replace will return 1.U, no influence for refill but bad
for perf counter

* mmu.tlb: give tlb_ld and tlb_st a name (in waveform)

* bump chisel to 3.5

* Remove deprecated 'toBool' && disable tl monitor

* Update RocketChip / Re-enable TLMonitor

* Makefile: remove '--infer-rw'

XiangShan is jointly released by ICT and PCL.

* better select policy timing
* unified RS enqueue ports for 4 ALUs
* wrap imm extractor into a module
* backend,rs: wrap dataArray in RawDataModuleTemplate
* should only bypass data between the same addr when allocate.valid

* better select policy timing
* unified RS enqueue ports for 4 ALUs
* wrap imm extractor into a module
* backend,rs: wrap dataArray in RawDataModuleTemplate
* should only bypass data between the same addr when allocate.valid

In this commit, we add License for XiangShan project. 

* emu: add --no-perf-counter option

Now perf counter result print will no longer be controlled by
--log-begin / --log-end

* emu: add --force-dump-result option

This option will override log_end to -1 when simulation finishs.
--no-perf-counter option is removed.

In this commit, we add support for using DPI-C calls to replace
DCache, PTW and L1plusCache. L2Cache and L3 Cache are also allowed to
be ignored or bypassed. Configurations are controlled by useFakeDCache,
useFakePTW, useFakeL1plusCache, useFakeL2Cache and useFakeL3Cache.
However, some configurations may not work correctly.

* difftest: use DPI-C to refactor difftest

In this commit, difftest is refactored with DPI-C calls.
There're a few reasons:
(1) From Verilator's manual, DPI-C calls should be more efficient than accessing from dut_ptr.
(2) DPI-C is cross-platform (Verilator, VCS, ...)
(3) difftest APIs are splited from emu.cpp to possibly support more backend platforms
(NEMU, Spike, ...)

The performance at this commit is quite slower than the original emu.
Performance issues will be fixed later.

* [WIP] SimTop: try to use 'XSTop' as soc

* CircularQueuePtr: ues F-bounded polymorphis instead implict helper

* Refactor parameters & Clean up code

* difftest: support basic difftest

* Support diffetst in new sim top

* Difftest; convert recode fmt to ieee754 when comparing fp regs

* Difftest: pass sign-ext pc to dpic functions && fix exception pc

* Debug: add int/exc inst wb to debug queue

* Difftest: pass sign-ext pc to dpic functions && fix exception pc

* Difftest: fix naive commit num limit
Co-authored-by: NYinan Xu <xuyinan1997@gmail.com>
Co-authored-by: NWilliam Wang <zeweiwang@outlook.com>

* Add ResetRegGen module to generate reset signals for different modules

To meet physical design requirements, reset signals for different modules
need to be generated respectively. This commit adds a ResetRegGen module
to automatically generate reset registers and connects different reset
signals to different modules, including l3cache, l2cache, core.
L1plusCache, MemBlock, IntegerBlock, FloatBlock, CtrlBlock, Frontend are
reset one by one.

XSPerfAccumulate: sum up performance values.
XSPerfHistogram: count the occurrence of performance values, split them
into bins, so that we can estimate their distribution.
XSPerfMax: get max of performance values.

Now we can put a performance value into several bins and count them.
In this way, we can get a distribution of this performance value.

* perf: set acc arg of XSPerf as false by default

* perf: add write-port competition counter for intBlock & floatBlock

* perf: remove prefix of perf signal

* perf: add perf-cnt for interface between frontend & backend

* perf: modify perf-cnt for prefetchers

* Ftq: bypass 'commit state' to fix dequeue bug

* perf: uptimize perf-cnt in ctrlblock & ftq

* perf: fix compilation problem in ftq

* perf: remove duplicate perf-cnt

* perf: calcu extra walk cycle exceeding frontend flush bubble

* Revert "perf: calcu extra walk cycle exceeding frontend flush bubble"

This reverts commit 2c30e9896b6af93a34e2d8d78055d810ebd0ac70.

* perf: add perf-cnt for ifu

* perf: add perf-cnt for rs

* RS: optimize numExist signal

* RS: fix some typo

* perf: add QueuePerf util to monitor usage info of queues

* perf: remove some duprecate perfcnt

previously the biggest problem was using '+' instead of '+&' to
do sums

* L1I/L1+:  Add performance counters for each way.

* Replacement: fix that lfsr always changes in random.

* Replacement: fix way method bugs

We do state change when calling way method, but in lack of a signal to
inform whether it is necessary to do state change, this might cause
problem.

* ICache: use new replacement method

* L1plusCache: change replacement method

* L1plusCache: add performance counters.

* L1plusCache: fix performance bug.

ICache miss penalty increases because that we miss the access method
in L1plusCache for replacement :)

* Replacement: change state in way method.

* State change is also needed when miss occurs, otherwise we will choose
a way that has been just refilled into cache as the victim.

* Optimize ctrlblock timing (#620)

* CtrlBlock: delay exception flush for 1 cycle

* CtrlBlock: delay load replay for 1 cycle

* roq: delay wb from exu for one clock cycle to meet timing

* CtrlBlock: fix pipeline bug between decode and rename
Co-authored-by: NYinan Xu <xuyinan1997@gmail.com>

* L1plusCache: use plru replacement policy.

* ICache: fix mmio bugs

1. MMIO cut helper uses packet align logic
2. still send req to uncache when flush

* ICache: change packet from mmio

use packet align as the mem

* IntrUncache: fix state bug

state will change into s_invalid and get stuck

* fix Registers that not being initiated

* perf: set acc arg of XSPerf as false by default

* perf: add write-port competition counter for intBlock & floatBlock

* perf: remove prefix of perf signal

* perf: add perf-cnt for interface between frontend & backend

* perf: modify perf-cnt for prefetchers

* WaitTable: add waittable framework

* WaitTable: get replay info from RedirectGenerator

* StoreQueue: maintain issuePtr for load rs

* RS: add loadWait to rs (only for load Unit's rs)

* WaitTable: fix update logic

* StoreQueue: fix issuePtr update logic

* chore: set loadWaitBit in ibuffer

* StoreQueue: fix issuePtrExt update logic

Former logic does not work well with mmio logic

We may also make sure that issuePtrExt is not before cmtPtrExt

* WaitTable: write with priority

* StoreQueue: fix issuePtrExt update logic for mmio

* chore: fix typos

* CSR: add slvpredctrl

* slvpredctrl will control load violation predict micro architecture

* WaitTable: use xor folded pc to index waittable
Co-authored-by: NZhangZifei <1773908404@qq.com>