3 based on Anton Blanchard microwatt dcache.vhdl
7 from enum
import Enum
, unique
9 from nmigen
import Module
, Signal
, Elaboratable
, Cat
, Repl
, Array
, Const
10 from nmutil
.util
import Display
12 from random
import randint
14 from nmigen
.cli
import main
15 from nmutil
.iocontrol
import RecordObject
16 from nmigen
.utils
import log2_int
17 from soc
.experiment
.mem_types
import (LoadStore1ToDCacheType
,
18 DCacheToLoadStore1Type
,
22 from soc
.experiment
.wb_types
import (WB_ADDR_BITS
, WB_DATA_BITS
, WB_SEL_BITS
,
23 WBAddrType
, WBDataType
, WBSelType
,
24 WBMasterOut
, WBSlaveOut
,
25 WBMasterOutVector
, WBSlaveOutVector
,
26 WBIOMasterOut
, WBIOSlaveOut
)
28 from soc
.experiment
.cache_ram
import CacheRam
29 #from soc.experiment.plru import PLRU
30 from nmutil
.plru
import PLRU
33 from nmigen_soc
.wishbone
.sram
import SRAM
34 from nmigen
import Memory
35 from nmigen
.cli
import rtlil
37 from nmigen
.back
.pysim
import Simulator
, Delay
, Settle
39 from nmigen
.sim
.cxxsim
import Simulator
, Delay
, Settle
40 from nmutil
.util
import wrap
43 # TODO: make these parameters of DCache at some point
44 LINE_SIZE
= 64 # Line size in bytes
45 NUM_LINES
= 16 # Number of lines in a set
46 NUM_WAYS
= 4 # Number of ways
47 TLB_SET_SIZE
= 64 # L1 DTLB entries per set
48 TLB_NUM_WAYS
= 2 # L1 DTLB number of sets
49 TLB_LG_PGSZ
= 12 # L1 DTLB log_2(page_size)
50 LOG_LENGTH
= 0 # Non-zero to enable log data collection
52 # BRAM organisation: We never access more than
53 # -- WB_DATA_BITS at a time so to save
54 # -- resources we make the array only that wide, and
55 # -- use consecutive indices for to make a cache "line"
57 # -- ROW_SIZE is the width in bytes of the BRAM
58 # -- (based on WB, so 64-bits)
59 ROW_SIZE
= WB_DATA_BITS
// 8;
61 # ROW_PER_LINE is the number of row (wishbone
62 # transactions) in a line
63 ROW_PER_LINE
= LINE_SIZE
// ROW_SIZE
65 # BRAM_ROWS is the number of rows in BRAM needed
66 # to represent the full dcache
67 BRAM_ROWS
= NUM_LINES
* ROW_PER_LINE
69 print ("ROW_SIZE", ROW_SIZE
)
70 print ("ROW_PER_LINE", ROW_PER_LINE
)
71 print ("BRAM_ROWS", BRAM_ROWS
)
72 print ("NUM_WAYS", NUM_WAYS
)
74 # Bit fields counts in the address
76 # REAL_ADDR_BITS is the number of real address
80 # ROW_BITS is the number of bits to select a row
81 ROW_BITS
= log2_int(BRAM_ROWS
)
83 # ROW_LINE_BITS is the number of bits to select
85 ROW_LINE_BITS
= log2_int(ROW_PER_LINE
)
87 # LINE_OFF_BITS is the number of bits for
88 # the offset in a cache line
89 LINE_OFF_BITS
= log2_int(LINE_SIZE
)
91 # ROW_OFF_BITS is the number of bits for
93 ROW_OFF_BITS
= log2_int(ROW_SIZE
)
95 # INDEX_BITS is the number if bits to
97 INDEX_BITS
= log2_int(NUM_LINES
)
99 # SET_SIZE_BITS is the log base 2 of the set size
100 SET_SIZE_BITS
= LINE_OFF_BITS
+ INDEX_BITS
102 # TAG_BITS is the number of bits of
103 # the tag part of the address
104 TAG_BITS
= REAL_ADDR_BITS
- SET_SIZE_BITS
106 # TAG_WIDTH is the width in bits of each way of the tag RAM
107 TAG_WIDTH
= TAG_BITS
+ 7 - ((TAG_BITS
+ 7) % 8)
109 # WAY_BITS is the number of bits to select a way
110 WAY_BITS
= log2_int(NUM_WAYS
)
112 # Example of layout for 32 lines of 64 bytes:
114 .. tag |index| line |
116 .. | |---| | ROW_LINE_BITS (3)
117 .. | |--- - --| LINE_OFF_BITS (6)
118 .. | |- --| ROW_OFF_BITS (3)
119 .. |----- ---| | ROW_BITS (8)
120 .. |-----| | INDEX_BITS (5)
121 .. --------| | TAG_BITS (45)
124 print ("Dcache TAG %d IDX %d ROW %d ROFF %d LOFF %d RLB %d" % \
125 (TAG_BITS
, INDEX_BITS
, ROW_BITS
,
126 ROW_OFF_BITS
, LINE_OFF_BITS
, ROW_LINE_BITS
))
127 print ("index @: %d-%d" % (LINE_OFF_BITS
, SET_SIZE_BITS
))
128 print ("row @: %d-%d" % (LINE_OFF_BITS
, ROW_OFF_BITS
))
129 print ("tag @: %d-%d width %d" % (SET_SIZE_BITS
, REAL_ADDR_BITS
, TAG_WIDTH
))
131 TAG_RAM_WIDTH
= TAG_WIDTH
* NUM_WAYS
134 return Array(Signal(TAG_RAM_WIDTH
, name
="cachetag_%d" % x
) \
135 for x
in range(NUM_LINES
))
137 def CacheValidBitsArray():
138 return Array(Signal(NUM_WAYS
, name
="cachevalid_%d" % x
) \
139 for x
in range(NUM_LINES
))
141 def RowPerLineValidArray():
142 return Array(Signal(name
="rows_valid%d" % x
) \
143 for x
in range(ROW_PER_LINE
))
146 TLB_SET_BITS
= log2_int(TLB_SET_SIZE
)
147 TLB_WAY_BITS
= log2_int(TLB_NUM_WAYS
)
148 TLB_EA_TAG_BITS
= 64 - (TLB_LG_PGSZ
+ TLB_SET_BITS
)
149 TLB_TAG_WAY_BITS
= TLB_NUM_WAYS
* TLB_EA_TAG_BITS
151 TLB_PTE_WAY_BITS
= TLB_NUM_WAYS
* TLB_PTE_BITS
;
154 return (1<<log2_int(x
, False)) == x
156 assert (LINE_SIZE
% ROW_SIZE
) == 0, "LINE_SIZE not multiple of ROW_SIZE"
157 assert ispow2(LINE_SIZE
), "LINE_SIZE not power of 2"
158 assert ispow2(NUM_LINES
), "NUM_LINES not power of 2"
159 assert ispow2(ROW_PER_LINE
), "ROW_PER_LINE not power of 2"
160 assert ROW_BITS
== (INDEX_BITS
+ ROW_LINE_BITS
), "geometry bits don't add up"
161 assert (LINE_OFF_BITS
== ROW_OFF_BITS
+ ROW_LINE_BITS
), \
162 "geometry bits don't add up"
163 assert REAL_ADDR_BITS
== (TAG_BITS
+ INDEX_BITS
+ LINE_OFF_BITS
), \
164 "geometry bits don't add up"
165 assert REAL_ADDR_BITS
== (TAG_BITS
+ ROW_BITS
+ ROW_OFF_BITS
), \
166 "geometry bits don't add up"
167 assert 64 == WB_DATA_BITS
, "Can't yet handle wb width that isn't 64-bits"
168 assert SET_SIZE_BITS
<= TLB_LG_PGSZ
, "Set indexed by virtual address"
171 def TLBValidBitsArray():
172 return Array(Signal(TLB_NUM_WAYS
) for x
in range(TLB_SET_SIZE
))
175 return Array(Signal(TLB_EA_TAG_BITS
) for x
in range (TLB_NUM_WAYS
))
178 return Array(Signal(TLB_TAG_WAY_BITS
) for x
in range (TLB_SET_SIZE
))
181 return Array(Signal(TLB_PTE_WAY_BITS
) for x
in range(TLB_SET_SIZE
))
184 return Array(Signal(WAY_BITS
, name
="hitway_%d" % x
) \
185 for x
in range(TLB_NUM_WAYS
))
187 # Cache RAM interface
189 return Array(Signal(WB_DATA_BITS
, name
="cache_out%d" % x
) \
190 for x
in range(NUM_WAYS
))
192 # PLRU output interface
194 return Array(Signal(WAY_BITS
) for x
in range(NUM_LINES
))
196 # TLB PLRU output interface
198 return Array(Signal(TLB_WAY_BITS
) for x
in range(TLB_SET_SIZE
))
200 # Helper functions to decode incoming requests
202 # Return the cache line index (tag index) for an address
204 return addr
[LINE_OFF_BITS
:SET_SIZE_BITS
]
206 # Return the cache row index (data memory) for an address
208 return addr
[ROW_OFF_BITS
:SET_SIZE_BITS
]
210 # Return the index of a row within a line
211 def get_row_of_line(row
):
212 return row
[:ROW_BITS
][:ROW_LINE_BITS
]
214 # Returns whether this is the last row of a line
215 def is_last_row_addr(addr
, last
):
216 return addr
[ROW_OFF_BITS
:LINE_OFF_BITS
] == last
218 # Returns whether this is the last row of a line
219 def is_last_row(row
, last
):
220 return get_row_of_line(row
) == last
222 # Return the next row in the current cache line. We use a
223 # dedicated function in order to limit the size of the
224 # generated adder to be only the bits within a cache line
225 # (3 bits with default settings)
227 row_v
= row
[0:ROW_LINE_BITS
] + 1
228 return Cat(row_v
[:ROW_LINE_BITS
], row
[ROW_LINE_BITS
:])
230 # Get the tag value from the address
232 return addr
[SET_SIZE_BITS
:REAL_ADDR_BITS
]
234 # Read a tag from a tag memory row
235 def read_tag(way
, tagset
):
236 return tagset
.word_select(way
, TAG_WIDTH
)[:TAG_BITS
]
238 # Read a TLB tag from a TLB tag memory row
239 def read_tlb_tag(way
, tags
):
240 return tags
.word_select(way
, TLB_EA_TAG_BITS
)
242 # Write a TLB tag to a TLB tag memory row
243 def write_tlb_tag(way
, tags
, tag
):
244 return read_tlb_tag(way
, tags
).eq(tag
)
246 # Read a PTE from a TLB PTE memory row
247 def read_tlb_pte(way
, ptes
):
248 return ptes
.word_select(way
, TLB_PTE_BITS
)
250 def write_tlb_pte(way
, ptes
, newpte
):
251 return read_tlb_pte(way
, ptes
).eq(newpte
)
254 # Record for storing permission, attribute, etc. bits from a PTE
255 class PermAttr(RecordObject
):
256 def __init__(self
, name
=None):
257 super().__init
__(name
=name
)
258 self
.reference
= Signal()
259 self
.changed
= Signal()
260 self
.nocache
= Signal()
262 self
.rd_perm
= Signal()
263 self
.wr_perm
= Signal()
266 def extract_perm_attr(pte
):
271 # Type of operation on a "valid" input
275 OP_BAD
= 1 # NC cache hit, TLB miss, prot/RC failure
276 OP_STCX_FAIL
= 2 # conditional store w/o reservation
277 OP_LOAD_HIT
= 3 # Cache hit on load
278 OP_LOAD_MISS
= 4 # Load missing cache
279 OP_LOAD_NC
= 5 # Non-cachable load
280 OP_STORE_HIT
= 6 # Store hitting cache
281 OP_STORE_MISS
= 7 # Store missing cache
284 # Cache state machine
287 IDLE
= 0 # Normal load hit processing
288 RELOAD_WAIT_ACK
= 1 # Cache reload wait ack
289 STORE_WAIT_ACK
= 2 # Store wait ack
290 NC_LOAD_WAIT_ACK
= 3 # Non-cachable load wait ack
295 # In order to make timing, we use the BRAMs with
296 # an output buffer, which means that the BRAM
297 # output is delayed by an extra cycle.
299 # Thus, the dcache has a 2-stage internal pipeline
300 # for cache hits with no stalls.
302 # All other operations are handled via stalling
303 # in the first stage.
305 # The second stage can thus complete a hit at the same
306 # time as the first stage emits a stall for a complex op.
308 # Stage 0 register, basically contains just the latched request
310 class RegStage0(RecordObject
):
311 def __init__(self
, name
=None):
312 super().__init
__(name
=name
)
313 self
.req
= LoadStore1ToDCacheType(name
="lsmem")
314 self
.tlbie
= Signal()
315 self
.doall
= Signal()
316 self
.tlbld
= Signal()
317 self
.mmu_req
= Signal() # indicates source of request
320 class MemAccessRequest(RecordObject
):
321 def __init__(self
, name
=None):
322 super().__init
__(name
=name
)
324 self
.valid
= Signal()
326 self
.real_addr
= Signal(REAL_ADDR_BITS
)
327 self
.data
= Signal(64)
328 self
.byte_sel
= Signal(8)
329 self
.hit_way
= Signal(WAY_BITS
)
330 self
.same_tag
= Signal()
331 self
.mmu_req
= Signal()
334 # First stage register, contains state for stage 1 of load hits
335 # and for the state machine used by all other operations
336 class RegStage1(RecordObject
):
337 def __init__(self
, name
=None):
338 super().__init
__(name
=name
)
339 # Info about the request
340 self
.full
= Signal() # have uncompleted request
341 self
.mmu_req
= Signal() # request is from MMU
342 self
.req
= MemAccessRequest(name
="reqmem")
345 self
.hit_way
= Signal(WAY_BITS
)
346 self
.hit_load_valid
= Signal()
347 self
.hit_index
= Signal(INDEX_BITS
)
348 self
.cache_hit
= Signal()
351 self
.tlb_hit
= Signal()
352 self
.tlb_hit_way
= Signal(TLB_NUM_WAYS
)
353 self
.tlb_hit_index
= Signal(TLB_WAY_BITS
)
355 # 2-stage data buffer for data forwarded from writes to reads
356 self
.forward_data1
= Signal(64)
357 self
.forward_data2
= Signal(64)
358 self
.forward_sel1
= Signal(8)
359 self
.forward_valid1
= Signal()
360 self
.forward_way1
= Signal(WAY_BITS
)
361 self
.forward_row1
= Signal(ROW_BITS
)
362 self
.use_forward1
= Signal()
363 self
.forward_sel
= Signal(8)
365 # Cache miss state (reload state machine)
366 self
.state
= Signal(State
)
368 self
.write_bram
= Signal()
369 self
.write_tag
= Signal()
370 self
.slow_valid
= Signal()
371 self
.real_adr
= Signal(REAL_ADDR_BITS
)
372 self
.wb
= WBMasterOut("wb")
373 self
.reload_tag
= Signal(TAG_BITS
)
374 self
.store_way
= Signal(WAY_BITS
)
375 self
.store_row
= Signal(ROW_BITS
)
376 self
.store_index
= Signal(INDEX_BITS
)
377 self
.end_row_ix
= Signal(ROW_LINE_BITS
)
378 self
.rows_valid
= RowPerLineValidArray()
379 self
.acks_pending
= Signal(3)
380 self
.inc_acks
= Signal()
381 self
.dec_acks
= Signal()
383 # Signals to complete (possibly with error)
384 self
.ls_valid
= Signal()
385 self
.ls_error
= Signal()
386 self
.mmu_done
= Signal()
387 self
.mmu_error
= Signal()
388 self
.cache_paradox
= Signal()
390 # Signal to complete a failed stcx.
391 self
.stcx_fail
= Signal()
394 # Reservation information
395 class Reservation(RecordObject
):
398 self
.valid
= Signal()
399 self
.addr
= Signal(64-LINE_OFF_BITS
)
402 class DTLBUpdate(Elaboratable
):
404 self
.tlbie
= Signal()
405 self
.tlbwe
= Signal()
406 self
.doall
= Signal()
407 self
.updated
= Signal()
408 self
.v_updated
= Signal()
409 self
.tlb_hit
= Signal()
410 self
.tlb_req_index
= Signal(TLB_SET_BITS
)
412 self
.tlb_hit_way
= Signal(TLB_WAY_BITS
)
413 self
.tlb_tag_way
= Signal(TLB_TAG_WAY_BITS
)
414 self
.tlb_pte_way
= Signal(TLB_PTE_WAY_BITS
)
415 self
.repl_way
= Signal(TLB_WAY_BITS
)
416 self
.eatag
= Signal(TLB_EA_TAG_BITS
)
417 self
.pte_data
= Signal(TLB_PTE_BITS
)
419 self
.dv
= Signal(TLB_PTE_WAY_BITS
)
421 self
.tb_out
= Signal(TLB_TAG_WAY_BITS
)
422 self
.pb_out
= Signal(TLB_NUM_WAYS
)
423 self
.db_out
= Signal(TLB_PTE_WAY_BITS
)
425 def elaborate(self
, platform
):
430 tagset
= Signal(TLB_TAG_WAY_BITS
)
431 pteset
= Signal(TLB_PTE_WAY_BITS
)
433 tb_out
, pb_out
, db_out
= self
.tb_out
, self
.pb_out
, self
.db_out
435 with m
.If(self
.tlbie
& self
.doall
):
436 pass # clear all back in parent
437 with m
.Elif(self
.tlbie
):
438 with m
.If(self
.tlb_hit
):
439 comb
+= db_out
.eq(self
.dv
)
440 comb
+= db_out
.bit_select(self
.tlb_hit_way
, 1).eq(1)
441 comb
+= self
.v_updated
.eq(1)
443 with m
.Elif(self
.tlbwe
):
445 comb
+= tagset
.eq(self
.tlb_tag_way
)
446 comb
+= write_tlb_tag(self
.repl_way
, tagset
, self
.eatag
)
447 comb
+= tb_out
.eq(tagset
)
449 comb
+= pteset
.eq(self
.tlb_pte_way
)
450 comb
+= write_tlb_pte(self
.repl_way
, pteset
, self
.pte_data
)
451 comb
+= pb_out
.eq(pteset
)
453 comb
+= db_out
.bit_select(self
.repl_way
, 1).eq(1)
455 comb
+= self
.updated
.eq(1)
456 comb
+= self
.v_updated
.eq(1)
461 class DCachePendingHit(Elaboratable
):
463 def __init__(self
, tlb_pte_way
, tlb_valid_way
, tlb_hit_way
,
464 cache_valid_idx
, cache_tag_set
,
469 self
.virt_mode
= Signal()
470 self
.is_hit
= Signal()
471 self
.tlb_hit
= Signal()
472 self
.hit_way
= Signal(WAY_BITS
)
473 self
.rel_match
= Signal()
474 self
.req_index
= Signal(INDEX_BITS
)
475 self
.reload_tag
= Signal(TAG_BITS
)
477 self
.tlb_hit_way
= tlb_hit_way
478 self
.tlb_pte_way
= tlb_pte_way
479 self
.tlb_valid_way
= tlb_valid_way
480 self
.cache_valid_idx
= cache_valid_idx
481 self
.cache_tag_set
= cache_tag_set
482 self
.req_addr
= req_addr
483 self
.hit_set
= hit_set
485 def elaborate(self
, platform
):
491 virt_mode
= self
.virt_mode
493 tlb_pte_way
= self
.tlb_pte_way
494 tlb_valid_way
= self
.tlb_valid_way
495 cache_valid_idx
= self
.cache_valid_idx
496 cache_tag_set
= self
.cache_tag_set
497 req_addr
= self
.req_addr
498 tlb_hit_way
= self
.tlb_hit_way
499 tlb_hit
= self
.tlb_hit
500 hit_set
= self
.hit_set
501 hit_way
= self
.hit_way
502 rel_match
= self
.rel_match
503 req_index
= self
.req_index
504 reload_tag
= self
.reload_tag
506 rel_matches
= Array(Signal(name
="rel_matches_%d" % i
) \
507 for i
in range(TLB_NUM_WAYS
))
508 hit_way_set
= HitWaySet()
510 # Test if pending request is a hit on any way
511 # In order to make timing in virtual mode,
512 # when we are using the TLB, we compare each
513 # way with each of the real addresses from each way of
514 # the TLB, and then decide later which match to use.
516 with m
.If(virt_mode
):
517 for j
in range(TLB_NUM_WAYS
):
518 s_tag
= Signal(TAG_BITS
, name
="s_tag%d" % j
)
520 s_pte
= Signal(TLB_PTE_BITS
)
521 s_ra
= Signal(REAL_ADDR_BITS
)
522 comb
+= s_pte
.eq(read_tlb_pte(j
, tlb_pte_way
))
523 comb
+= s_ra
.eq(Cat(req_addr
[0:TLB_LG_PGSZ
],
524 s_pte
[TLB_LG_PGSZ
:REAL_ADDR_BITS
]))
525 comb
+= s_tag
.eq(get_tag(s_ra
))
527 for i
in range(NUM_WAYS
):
528 is_tag_hit
= Signal(name
="is_tag_hit_%d_%d" % (j
, i
))
529 comb
+= is_tag_hit
.eq(go
& cache_valid_idx
[i
] &
530 (read_tag(i
, cache_tag_set
) == s_tag
)
532 with m
.If(is_tag_hit
):
533 comb
+= hit_way_set
[j
].eq(i
)
535 comb
+= hit_set
[j
].eq(s_hit
)
536 with m
.If(s_tag
== reload_tag
):
537 comb
+= rel_matches
[j
].eq(1)
539 comb
+= is_hit
.eq(hit_set
[tlb_hit_way
])
540 comb
+= hit_way
.eq(hit_way_set
[tlb_hit_way
])
541 comb
+= rel_match
.eq(rel_matches
[tlb_hit_way
])
543 s_tag
= Signal(TAG_BITS
)
544 comb
+= s_tag
.eq(get_tag(req_addr
))
545 for i
in range(NUM_WAYS
):
546 is_tag_hit
= Signal(name
="is_tag_hit_%d" % i
)
547 comb
+= is_tag_hit
.eq(go
& cache_valid_idx
[i
] &
548 (read_tag(i
, cache_tag_set
) == s_tag
))
549 with m
.If(is_tag_hit
):
550 comb
+= hit_way
.eq(i
)
552 with m
.If(s_tag
== reload_tag
):
553 comb
+= rel_match
.eq(1)
558 class DCache(Elaboratable
):
559 """Set associative dcache write-through
560 TODO (in no specific order):
561 * See list in icache.vhdl
562 * Complete load misses on the cycle when WB data comes instead of
563 at the end of line (this requires dealing with requests coming in
567 self
.d_in
= LoadStore1ToDCacheType("d_in")
568 self
.d_out
= DCacheToLoadStore1Type("d_out")
570 self
.m_in
= MMUToDCacheType("m_in")
571 self
.m_out
= DCacheToMMUType("m_out")
573 self
.stall_out
= Signal()
575 self
.wb_out
= WBMasterOut()
576 self
.wb_in
= WBSlaveOut()
578 self
.log_out
= Signal(20)
580 def stage_0(self
, m
, r0
, r1
, r0_full
):
581 """Latch the request in r0.req as long as we're not stalling
585 d_in
, d_out
, m_in
= self
.d_in
, self
.d_out
, self
.m_in
587 r
= RegStage0("stage0")
589 # TODO, this goes in unit tests and formal proofs
590 with m
.If(d_in
.valid
& m_in
.valid
):
591 sync
+= Display("request collision loadstore vs MMU")
593 with m
.If(m_in
.valid
):
594 sync
+= r
.req
.valid
.eq(1)
595 sync
+= r
.req
.load
.eq(~
(m_in
.tlbie | m_in
.tlbld
))
596 sync
+= r
.req
.dcbz
.eq(0)
597 sync
+= r
.req
.nc
.eq(0)
598 sync
+= r
.req
.reserve
.eq(0)
599 sync
+= r
.req
.virt_mode
.eq(0)
600 sync
+= r
.req
.priv_mode
.eq(1)
601 sync
+= r
.req
.addr
.eq(m_in
.addr
)
602 sync
+= r
.req
.data
.eq(m_in
.pte
)
603 sync
+= r
.req
.byte_sel
.eq(~
0) # Const -1 sets all to 0b111....
604 sync
+= r
.tlbie
.eq(m_in
.tlbie
)
605 sync
+= r
.doall
.eq(m_in
.doall
)
606 sync
+= r
.tlbld
.eq(m_in
.tlbld
)
607 sync
+= r
.mmu_req
.eq(1)
609 sync
+= r
.req
.eq(d_in
)
610 sync
+= r
.tlbie
.eq(0)
611 sync
+= r
.doall
.eq(0)
612 sync
+= r
.tlbld
.eq(0)
613 sync
+= r
.mmu_req
.eq(0)
614 with m
.If(~
(r1
.full
& r0_full
)):
616 sync
+= r0_full
.eq(r
.req
.valid
)
618 def tlb_read(self
, m
, r0_stall
, tlb_valid_way
,
619 tlb_tag_way
, tlb_pte_way
, dtlb_valid_bits
,
620 dtlb_tags
, dtlb_ptes
):
622 Operates in the second cycle on the request latched in r0.req.
623 TLB updates write the entry at the end of the second cycle.
627 m_in
, d_in
= self
.m_in
, self
.d_in
629 index
= Signal(TLB_SET_BITS
)
630 addrbits
= Signal(TLB_SET_BITS
)
633 amax
= TLB_LG_PGSZ
+ TLB_SET_BITS
635 with m
.If(m_in
.valid
):
636 comb
+= addrbits
.eq(m_in
.addr
[amin
: amax
])
638 comb
+= addrbits
.eq(d_in
.addr
[amin
: amax
])
639 comb
+= index
.eq(addrbits
)
641 # If we have any op and the previous op isn't finished,
642 # then keep the same output for next cycle.
643 with m
.If(~r0_stall
):
644 sync
+= tlb_valid_way
.eq(dtlb_valid_bits
[index
])
645 sync
+= tlb_tag_way
.eq(dtlb_tags
[index
])
646 sync
+= tlb_pte_way
.eq(dtlb_ptes
[index
])
648 def maybe_tlb_plrus(self
, m
, r1
, tlb_plru_victim
):
649 """Generate TLB PLRUs
654 if TLB_NUM_WAYS
== 0:
656 for i
in range(TLB_SET_SIZE
):
658 tlb_plru
= PLRU(TLB_WAY_BITS
)
659 setattr(m
.submodules
, "maybe_plru_%d" % i
, tlb_plru
)
660 tlb_plru_acc_en
= Signal()
662 comb
+= tlb_plru_acc_en
.eq(r1
.tlb_hit
& (r1
.tlb_hit_index
== i
))
663 comb
+= tlb_plru
.acc_en
.eq(tlb_plru_acc_en
)
664 comb
+= tlb_plru
.acc_i
.eq(r1
.tlb_hit_way
)
665 comb
+= tlb_plru_victim
[i
].eq(tlb_plru
.lru_o
)
667 def tlb_search(self
, m
, tlb_req_index
, r0
, r0_valid
,
668 tlb_valid_way
, tlb_tag_way
, tlb_hit_way
,
669 tlb_pte_way
, pte
, tlb_hit
, valid_ra
, perm_attr
, ra
):
674 hitway
= Signal(TLB_WAY_BITS
)
676 eatag
= Signal(TLB_EA_TAG_BITS
)
678 TLB_LG_END
= TLB_LG_PGSZ
+ TLB_SET_BITS
679 comb
+= tlb_req_index
.eq(r0
.req
.addr
[TLB_LG_PGSZ
: TLB_LG_END
])
680 comb
+= eatag
.eq(r0
.req
.addr
[TLB_LG_END
: 64 ])
682 for i
in range(TLB_NUM_WAYS
):
683 is_tag_hit
= Signal()
684 comb
+= is_tag_hit
.eq(tlb_valid_way
[i
]
685 & (read_tlb_tag(i
, tlb_tag_way
) == eatag
))
686 with m
.If(is_tag_hit
):
690 comb
+= tlb_hit
.eq(hit
& r0_valid
)
691 comb
+= tlb_hit_way
.eq(hitway
)
694 comb
+= pte
.eq(read_tlb_pte(hitway
, tlb_pte_way
))
697 comb
+= valid_ra
.eq(tlb_hit | ~r0
.req
.virt_mode
)
698 with m
.If(r0
.req
.virt_mode
):
699 comb
+= ra
.eq(Cat(Const(0, ROW_OFF_BITS
),
700 r0
.req
.addr
[ROW_OFF_BITS
:TLB_LG_PGSZ
],
701 pte
[TLB_LG_PGSZ
:REAL_ADDR_BITS
]))
702 comb
+= perm_attr
.reference
.eq(pte
[8])
703 comb
+= perm_attr
.changed
.eq(pte
[7])
704 comb
+= perm_attr
.nocache
.eq(pte
[5])
705 comb
+= perm_attr
.priv
.eq(pte
[3])
706 comb
+= perm_attr
.rd_perm
.eq(pte
[2])
707 comb
+= perm_attr
.wr_perm
.eq(pte
[1])
709 comb
+= ra
.eq(Cat(Const(0, ROW_OFF_BITS
),
710 r0
.req
.addr
[ROW_OFF_BITS
:REAL_ADDR_BITS
]))
712 comb
+= perm_attr
.reference
.eq(1)
713 comb
+= perm_attr
.changed
.eq(1)
714 comb
+= perm_attr
.nocache
.eq(0)
715 comb
+= perm_attr
.priv
.eq(1)
716 comb
+= perm_attr
.rd_perm
.eq(1)
717 comb
+= perm_attr
.wr_perm
.eq(1)
719 def tlb_update(self
, m
, r0_valid
, r0
, dtlb_valid_bits
, tlb_req_index
,
720 tlb_hit_way
, tlb_hit
, tlb_plru_victim
, tlb_tag_way
,
721 dtlb_tags
, tlb_pte_way
, dtlb_ptes
):
729 comb
+= tlbie
.eq(r0_valid
& r0
.tlbie
)
730 comb
+= tlbwe
.eq(r0_valid
& r0
.tlbld
)
732 m
.submodules
.tlb_update
= d
= DTLBUpdate()
733 with m
.If(tlbie
& r0
.doall
):
734 # clear all valid bits at once
735 for i
in range(TLB_SET_SIZE
):
736 sync
+= dtlb_valid_bits
[i
].eq(0)
737 with m
.If(d
.updated
):
738 sync
+= dtlb_tags
[tlb_req_index
].eq(d
.tb_out
)
739 sync
+= dtlb_ptes
[tlb_req_index
].eq(d
.pb_out
)
740 with m
.If(d
.v_updated
):
741 sync
+= dtlb_valid_bits
[tlb_req_index
].eq(d
.db_out
)
743 comb
+= d
.dv
.eq(dtlb_valid_bits
[tlb_req_index
])
745 comb
+= d
.tlbie
.eq(tlbie
)
746 comb
+= d
.tlbwe
.eq(tlbwe
)
747 comb
+= d
.doall
.eq(r0
.doall
)
748 comb
+= d
.tlb_hit
.eq(tlb_hit
)
749 comb
+= d
.tlb_hit_way
.eq(tlb_hit_way
)
750 comb
+= d
.tlb_tag_way
.eq(tlb_tag_way
)
751 comb
+= d
.tlb_pte_way
.eq(tlb_pte_way
)
752 comb
+= d
.tlb_req_index
.eq(tlb_req_index
)
755 comb
+= d
.repl_way
.eq(tlb_hit_way
)
757 comb
+= d
.repl_way
.eq(tlb_plru_victim
[tlb_req_index
])
758 comb
+= d
.eatag
.eq(r0
.req
.addr
[TLB_LG_PGSZ
+ TLB_SET_BITS
:64])
759 comb
+= d
.pte_data
.eq(r0
.req
.data
)
761 def maybe_plrus(self
, m
, r1
, plru_victim
):
767 if TLB_NUM_WAYS
== 0:
770 for i
in range(NUM_LINES
):
772 plru
= PLRU(WAY_BITS
)
773 setattr(m
.submodules
, "plru%d" % i
, plru
)
774 plru_acc_en
= Signal()
776 comb
+= plru_acc_en
.eq(r1
.cache_hit
& (r1
.hit_index
== i
))
777 comb
+= plru
.acc_en
.eq(plru_acc_en
)
778 comb
+= plru
.acc_i
.eq(r1
.hit_way
)
779 comb
+= plru_victim
[i
].eq(plru
.lru_o
)
781 def cache_tag_read(self
, m
, r0_stall
, req_index
, cache_tag_set
, cache_tags
):
782 """Cache tag RAM read port
786 m_in
, d_in
= self
.m_in
, self
.d_in
788 index
= Signal(INDEX_BITS
)
791 comb
+= index
.eq(req_index
)
792 with m
.Elif(m_in
.valid
):
793 comb
+= index
.eq(get_index(m_in
.addr
))
795 comb
+= index
.eq(get_index(d_in
.addr
))
796 sync
+= cache_tag_set
.eq(cache_tags
[index
])
798 def dcache_request(self
, m
, r0
, ra
, req_index
, req_row
, req_tag
,
799 r0_valid
, r1
, cache_valids
, replace_way
,
800 use_forward1_next
, use_forward2_next
,
801 req_hit_way
, plru_victim
, rc_ok
, perm_attr
,
802 valid_ra
, perm_ok
, access_ok
, req_op
, req_go
,
804 tlb_hit
, tlb_hit_way
, tlb_valid_way
, cache_tag_set
,
805 cancel_store
, req_same_tag
, r0_stall
, early_req_row
):
806 """Cache request parsing and hit detection
811 m_in
, d_in
= self
.m_in
, self
.d_in
814 hit_way
= Signal(WAY_BITS
)
819 hit_set
= Array(Signal(name
="hit_set_%d" % i
) \
820 for i
in range(TLB_NUM_WAYS
))
821 cache_valid_idx
= Signal(NUM_WAYS
)
823 # Extract line, row and tag from request
824 comb
+= req_index
.eq(get_index(r0
.req
.addr
))
825 comb
+= req_row
.eq(get_row(r0
.req
.addr
))
826 comb
+= req_tag
.eq(get_tag(ra
))
828 if False: # display on comb is a bit... busy.
829 comb
+= Display("dcache_req addr:%x ra: %x idx: %x tag: %x row: %x",
830 r0
.req
.addr
, ra
, req_index
, req_tag
, req_row
)
832 comb
+= go
.eq(r0_valid
& ~
(r0
.tlbie | r0
.tlbld
) & ~r1
.ls_error
)
833 comb
+= cache_valid_idx
.eq(cache_valids
[req_index
])
835 m
.submodules
.dcache_pend
= dc
= DCachePendingHit(tlb_pte_way
,
836 tlb_valid_way
, tlb_hit_way
,
837 cache_valid_idx
, cache_tag_set
,
841 comb
+= dc
.tlb_hit
.eq(tlb_hit
)
842 comb
+= dc
.reload_tag
.eq(r1
.reload_tag
)
843 comb
+= dc
.virt_mode
.eq(r0
.req
.virt_mode
)
845 comb
+= dc
.req_index
.eq(req_index
)
846 comb
+= is_hit
.eq(dc
.is_hit
)
847 comb
+= hit_way
.eq(dc
.hit_way
)
848 comb
+= req_same_tag
.eq(dc
.rel_match
)
850 # See if the request matches the line currently being reloaded
851 with m
.If((r1
.state
== State
.RELOAD_WAIT_ACK
) &
852 (req_index
== r1
.store_index
) & req_same_tag
):
853 # For a store, consider this a hit even if the row isn't
854 # valid since it will be by the time we perform the store.
855 # For a load, check the appropriate row valid bit.
856 rrow
= Signal(ROW_LINE_BITS
)
857 comb
+= rrow
.eq(req_row
)
858 valid
= r1
.rows_valid
[rrow
]
859 comb
+= is_hit
.eq(~r0
.req
.load | valid
)
860 comb
+= hit_way
.eq(replace_way
)
862 # Whether to use forwarded data for a load or not
863 with m
.If((get_row(r1
.req
.real_addr
) == req_row
) &
864 (r1
.req
.hit_way
== hit_way
)):
865 # Only need to consider r1.write_bram here, since if we
866 # are writing refill data here, then we don't have a
867 # cache hit this cycle on the line being refilled.
868 # (There is the possibility that the load following the
869 # load miss that started the refill could be to the old
870 # contents of the victim line, since it is a couple of
871 # cycles after the refill starts before we see the updated
872 # cache tag. In that case we don't use the bypass.)
873 comb
+= use_forward1_next
.eq(r1
.write_bram
)
874 with m
.If((r1
.forward_row1
== req_row
) & (r1
.forward_way1
== hit_way
)):
875 comb
+= use_forward2_next
.eq(r1
.forward_valid1
)
877 # The way that matched on a hit
878 comb
+= req_hit_way
.eq(hit_way
)
880 # The way to replace on a miss
881 with m
.If(r1
.write_tag
):
882 comb
+= replace_way
.eq(plru_victim
[r1
.store_index
])
884 comb
+= replace_way
.eq(r1
.store_way
)
886 # work out whether we have permission for this access
887 # NB we don't yet implement AMR, thus no KUAP
888 comb
+= rc_ok
.eq(perm_attr
.reference
889 & (r0
.req
.load | perm_attr
.changed
)
891 comb
+= perm_ok
.eq((r0
.req
.priv_mode | ~perm_attr
.priv
) &
893 (r0
.req
.load
& perm_attr
.rd_perm
)))
894 comb
+= access_ok
.eq(valid_ra
& perm_ok
& rc_ok
)
895 # Combine the request and cache hit status to decide what
896 # operation needs to be done
897 comb
+= nc
.eq(r0
.req
.nc | perm_attr
.nocache
)
898 comb
+= op
.eq(Op
.OP_NONE
)
900 with m
.If(~access_ok
):
901 comb
+= op
.eq(Op
.OP_BAD
)
902 with m
.Elif(cancel_store
):
903 comb
+= op
.eq(Op
.OP_STCX_FAIL
)
905 comb
+= opsel
.eq(Cat(is_hit
, nc
, r0
.req
.load
))
906 with m
.Switch(opsel
):
907 with m
.Case(0b101): comb
+= op
.eq(Op
.OP_LOAD_HIT
)
908 with m
.Case(0b100): comb
+= op
.eq(Op
.OP_LOAD_MISS
)
909 with m
.Case(0b110): comb
+= op
.eq(Op
.OP_LOAD_NC
)
910 with m
.Case(0b001): comb
+= op
.eq(Op
.OP_STORE_HIT
)
911 with m
.Case(0b000): comb
+= op
.eq(Op
.OP_STORE_MISS
)
912 with m
.Case(0b010): comb
+= op
.eq(Op
.OP_STORE_MISS
)
913 with m
.Case(0b011): comb
+= op
.eq(Op
.OP_BAD
)
914 with m
.Case(0b111): comb
+= op
.eq(Op
.OP_BAD
)
915 comb
+= req_op
.eq(op
)
916 comb
+= req_go
.eq(go
)
918 # Version of the row number that is valid one cycle earlier
919 # in the cases where we need to read the cache data BRAM.
920 # If we're stalling then we need to keep reading the last
922 with m
.If(~r0_stall
):
923 with m
.If(m_in
.valid
):
924 comb
+= early_req_row
.eq(get_row(m_in
.addr
))
926 comb
+= early_req_row
.eq(get_row(d_in
.addr
))
928 comb
+= early_req_row
.eq(req_row
)
930 def reservation_comb(self
, m
, cancel_store
, set_rsrv
, clear_rsrv
,
931 r0_valid
, r0
, reservation
):
932 """Handle load-with-reservation and store-conditional instructions
937 with m
.If(r0_valid
& r0
.req
.reserve
):
938 # XXX generate alignment interrupt if address
939 # is not aligned XXX or if r0.req.nc = '1'
940 with m
.If(r0
.req
.load
):
941 comb
+= set_rsrv
.eq(1) # load with reservation
943 comb
+= clear_rsrv
.eq(1) # store conditional
944 with m
.If(~reservation
.valid |
945 (r0
.req
.addr
[LINE_OFF_BITS
:64] != reservation
.addr
)):
946 comb
+= cancel_store
.eq(1)
948 def reservation_reg(self
, m
, r0_valid
, access_ok
, set_rsrv
, clear_rsrv
,
954 with m
.If(r0_valid
& access_ok
):
955 with m
.If(clear_rsrv
):
956 sync
+= reservation
.valid
.eq(0)
957 with m
.Elif(set_rsrv
):
958 sync
+= reservation
.valid
.eq(1)
959 sync
+= reservation
.addr
.eq(r0
.req
.addr
[LINE_OFF_BITS
:64])
961 def writeback_control(self
, m
, r1
, cache_out
):
962 """Return data for loads & completion control logic
966 d_out
, m_out
= self
.d_out
, self
.m_out
968 data_out
= Signal(64)
969 data_fwd
= Signal(64)
971 # Use the bypass if are reading the row that was
972 # written 1 or 2 cycles ago, including for the
973 # slow_valid = 1 case (i.e. completing a load
974 # miss or a non-cacheable load).
975 with m
.If(r1
.use_forward1
):
976 comb
+= data_fwd
.eq(r1
.forward_data1
)
978 comb
+= data_fwd
.eq(r1
.forward_data2
)
980 comb
+= data_out
.eq(cache_out
[r1
.hit_way
])
983 with m
.If(r1
.forward_sel
[i
]):
984 dsel
= data_fwd
.word_select(i
, 8)
985 comb
+= data_out
.word_select(i
, 8).eq(dsel
)
987 comb
+= d_out
.valid
.eq(r1
.ls_valid
)
988 comb
+= d_out
.data
.eq(data_out
)
989 comb
+= d_out
.store_done
.eq(~r1
.stcx_fail
)
990 comb
+= d_out
.error
.eq(r1
.ls_error
)
991 comb
+= d_out
.cache_paradox
.eq(r1
.cache_paradox
)
994 comb
+= m_out
.done
.eq(r1
.mmu_done
)
995 comb
+= m_out
.err
.eq(r1
.mmu_error
)
996 comb
+= m_out
.data
.eq(data_out
)
998 # We have a valid load or store hit or we just completed
999 # a slow op such as a load miss, a NC load or a store
1001 # Note: the load hit is delayed by one cycle. However it
1002 # can still not collide with r.slow_valid (well unless I
1003 # miscalculated) because slow_valid can only be set on a
1004 # subsequent request and not on its first cycle (the state
1005 # machine must have advanced), which makes slow_valid
1006 # at least 2 cycles from the previous hit_load_valid.
1008 # Sanity: Only one of these must be set in any given cycle
1010 if False: # TODO: need Display to get this to work
1011 assert (r1
.slow_valid
& r1
.stcx_fail
) != 1, \
1012 "unexpected slow_valid collision with stcx_fail"
1014 assert ((r1
.slow_valid | r1
.stcx_fail
) | r1
.hit_load_valid
) != 1, \
1015 "unexpected hit_load_delayed collision with slow_valid"
1017 with m
.If(~r1
.mmu_req
):
1018 # Request came from loadstore1...
1019 # Load hit case is the standard path
1020 with m
.If(r1
.hit_load_valid
):
1021 sync
+= Display("completing load hit data=%x", data_out
)
1023 # error cases complete without stalling
1024 with m
.If(r1
.ls_error
):
1025 sync
+= Display("completing ld/st with error")
1027 # Slow ops (load miss, NC, stores)
1028 with m
.If(r1
.slow_valid
):
1029 sync
+= Display("completing store or load miss data=%x",
1033 # Request came from MMU
1034 with m
.If(r1
.hit_load_valid
):
1035 sync
+= Display("completing load hit to MMU, data=%x",
1037 # error cases complete without stalling
1038 with m
.If(r1
.mmu_error
):
1039 sync
+= Display("combpleting MMU ld with error")
1041 # Slow ops (i.e. load miss)
1042 with m
.If(r1
.slow_valid
):
1043 sync
+= Display("completing MMU load miss, data=%x",
1046 def rams(self
, m
, r1
, early_req_row
, cache_out
, replace_way
):
1048 Generate a cache RAM for each way. This handles the normal
1049 reads, writes from reloads and the special store-hit update
1052 Note: the BRAMs have an extra read buffer, meaning the output
1053 is pipelined an extra cycle. This differs from the
1054 icache. The writeback logic needs to take that into
1055 account by using 1-cycle delayed signals for load hits.
1060 for i
in range(NUM_WAYS
):
1061 do_read
= Signal(name
="do_rd%d" % i
)
1062 rd_addr
= Signal(ROW_BITS
)
1063 do_write
= Signal(name
="do_wr%d" % i
)
1064 wr_addr
= Signal(ROW_BITS
)
1065 wr_data
= Signal(WB_DATA_BITS
)
1066 wr_sel
= Signal(ROW_SIZE
)
1067 wr_sel_m
= Signal(ROW_SIZE
)
1068 _d_out
= Signal(WB_DATA_BITS
, name
="dout_%d" % i
)
1070 way
= CacheRam(ROW_BITS
, WB_DATA_BITS
, True)
1071 setattr(m
.submodules
, "cacheram_%d" % i
, way
)
1073 comb
+= way
.rd_en
.eq(do_read
)
1074 comb
+= way
.rd_addr
.eq(rd_addr
)
1075 comb
+= _d_out
.eq(way
.rd_data_o
)
1076 comb
+= way
.wr_sel
.eq(wr_sel_m
)
1077 comb
+= way
.wr_addr
.eq(wr_addr
)
1078 comb
+= way
.wr_data
.eq(wr_data
)
1081 comb
+= do_read
.eq(1)
1082 comb
+= rd_addr
.eq(early_req_row
[:ROW_BITS
])
1083 comb
+= cache_out
[i
].eq(_d_out
)
1087 # Defaults to wishbone read responses (cache refill)
1089 # For timing, the mux on wr_data/sel/addr is not
1090 # dependent on anything other than the current state.
1092 with m
.If(r1
.write_bram
):
1093 # Write store data to BRAM. This happens one
1094 # cycle after the store is in r0.
1095 comb
+= wr_data
.eq(r1
.req
.data
)
1096 comb
+= wr_sel
.eq(r1
.req
.byte_sel
)
1097 comb
+= wr_addr
.eq(get_row(r1
.req
.real_addr
))
1099 with m
.If(i
== r1
.req
.hit_way
):
1100 comb
+= do_write
.eq(1)
1102 # Otherwise, we might be doing a reload or a DCBZ
1104 comb
+= wr_data
.eq(0)
1106 comb
+= wr_data
.eq(wb_in
.dat
)
1107 comb
+= wr_addr
.eq(r1
.store_row
)
1108 comb
+= wr_sel
.eq(~
0) # all 1s
1110 with m
.If((r1
.state
== State
.RELOAD_WAIT_ACK
)
1111 & wb_in
.ack
& (replace_way
== i
)):
1112 comb
+= do_write
.eq(1)
1114 # Mask write selects with do_write since BRAM
1115 # doesn't have a global write-enable
1116 with m
.If(do_write
):
1117 comb
+= wr_sel_m
.eq(wr_sel
)
1119 # Cache hit synchronous machine for the easy case.
1120 # This handles load hits.
1121 # It also handles error cases (TLB miss, cache paradox)
1122 def dcache_fast_hit(self
, m
, req_op
, r0_valid
, r0
, r1
,
1123 req_hit_way
, req_index
, req_tag
, access_ok
,
1124 tlb_hit
, tlb_hit_way
, tlb_req_index
):
1129 with m
.If(req_op
!= Op
.OP_NONE
):
1130 sync
+= Display("op:%d addr:%x nc: %d idx: %x tag: %x way: %x",
1131 req_op
, r0
.req
.addr
, r0
.req
.nc
,
1132 req_index
, req_tag
, req_hit_way
)
1134 with m
.If(r0_valid
):
1135 sync
+= r1
.mmu_req
.eq(r0
.mmu_req
)
1137 # Fast path for load/store hits.
1138 # Set signals for the writeback controls.
1139 sync
+= r1
.hit_way
.eq(req_hit_way
)
1140 sync
+= r1
.hit_index
.eq(req_index
)
1142 with m
.If(req_op
== Op
.OP_LOAD_HIT
):
1143 sync
+= r1
.hit_load_valid
.eq(1)
1145 sync
+= r1
.hit_load_valid
.eq(0)
1147 with m
.If((req_op
== Op
.OP_LOAD_HIT
) |
(req_op
== Op
.OP_STORE_HIT
)):
1148 sync
+= r1
.cache_hit
.eq(1)
1150 sync
+= r1
.cache_hit
.eq(0)
1152 with m
.If(req_op
== Op
.OP_BAD
):
1153 # Display(f"Signalling ld/st error valid_ra={valid_ra}"
1154 # f"rc_ok={rc_ok} perm_ok={perm_ok}"
1155 sync
+= r1
.ls_error
.eq(~r0
.mmu_req
)
1156 sync
+= r1
.mmu_error
.eq(r0
.mmu_req
)
1157 sync
+= r1
.cache_paradox
.eq(access_ok
)
1160 sync
+= r1
.ls_error
.eq(0)
1161 sync
+= r1
.mmu_error
.eq(0)
1162 sync
+= r1
.cache_paradox
.eq(0)
1164 with m
.If(req_op
== Op
.OP_STCX_FAIL
):
1167 sync
+= r1
.stcx_fail
.eq(0)
1169 # Record TLB hit information for updating TLB PLRU
1170 sync
+= r1
.tlb_hit
.eq(tlb_hit
)
1171 sync
+= r1
.tlb_hit_way
.eq(tlb_hit_way
)
1172 sync
+= r1
.tlb_hit_index
.eq(tlb_req_index
)
1174 # Memory accesses are handled by this state machine:
1176 # * Cache load miss/reload (in conjunction with "rams")
1177 # * Load hits for non-cachable forms
1178 # * Stores (the collision case is handled in "rams")
1180 # All wishbone requests generation is done here.
1181 # This machine operates at stage 1.
1182 def dcache_slow(self
, m
, r1
, use_forward1_next
, use_forward2_next
,
1183 cache_valids
, r0
, replace_way
,
1184 req_hit_way
, req_same_tag
,
1185 r0_valid
, req_op
, cache_tags
, req_go
, ra
):
1191 req
= MemAccessRequest("mreq_ds")
1193 adjust_acks
= Signal(3)
1195 req_row
= Signal(ROW_BITS
)
1196 req_idx
= Signal(INDEX_BITS
)
1197 req_tag
= Signal(TAG_BITS
)
1198 comb
+= req_idx
.eq(get_index(req
.real_addr
))
1199 comb
+= req_row
.eq(get_row(req
.real_addr
))
1200 comb
+= req_tag
.eq(get_tag(req
.real_addr
))
1202 sync
+= r1
.use_forward1
.eq(use_forward1_next
)
1203 sync
+= r1
.forward_sel
.eq(0)
1205 with m
.If(use_forward1_next
):
1206 sync
+= r1
.forward_sel
.eq(r1
.req
.byte_sel
)
1207 with m
.Elif(use_forward2_next
):
1208 sync
+= r1
.forward_sel
.eq(r1
.forward_sel1
)
1210 sync
+= r1
.forward_data2
.eq(r1
.forward_data1
)
1211 with m
.If(r1
.write_bram
):
1212 sync
+= r1
.forward_data1
.eq(r1
.req
.data
)
1213 sync
+= r1
.forward_sel1
.eq(r1
.req
.byte_sel
)
1214 sync
+= r1
.forward_way1
.eq(r1
.req
.hit_way
)
1215 sync
+= r1
.forward_row1
.eq(get_row(r1
.req
.real_addr
))
1216 sync
+= r1
.forward_valid1
.eq(1)
1219 sync
+= r1
.forward_data1
.eq(0)
1221 sync
+= r1
.forward_data1
.eq(wb_in
.dat
)
1222 sync
+= r1
.forward_sel1
.eq(~
0) # all 1s
1223 sync
+= r1
.forward_way1
.eq(replace_way
)
1224 sync
+= r1
.forward_row1
.eq(r1
.store_row
)
1225 sync
+= r1
.forward_valid1
.eq(0)
1227 # One cycle pulses reset
1228 sync
+= r1
.slow_valid
.eq(0)
1229 sync
+= r1
.write_bram
.eq(0)
1230 sync
+= r1
.inc_acks
.eq(0)
1231 sync
+= r1
.dec_acks
.eq(0)
1233 sync
+= r1
.ls_valid
.eq(0)
1234 # complete tlbies and TLB loads in the third cycle
1235 sync
+= r1
.mmu_done
.eq(r0_valid
& (r0
.tlbie | r0
.tlbld
))
1237 with m
.If((req_op
== Op
.OP_LOAD_HIT
)
1238 |
(req_op
== Op
.OP_STCX_FAIL
)):
1239 with m
.If(~r0
.mmu_req
):
1240 sync
+= r1
.ls_valid
.eq(1)
1242 sync
+= r1
.mmu_done
.eq(1)
1244 with m
.If(r1
.write_tag
):
1245 # Store new tag in selected way
1246 for i
in range(NUM_WAYS
):
1247 with m
.If(i
== replace_way
):
1248 ct
= Signal(TAG_RAM_WIDTH
)
1249 comb
+= ct
.eq(cache_tags
[r1
.store_index
])
1250 comb
+= ct
.word_select(i
, TAG_WIDTH
).eq(r1
.reload_tag
)
1251 sync
+= cache_tags
[r1
.store_index
].eq(ct
)
1252 sync
+= r1
.store_way
.eq(replace_way
)
1253 sync
+= r1
.write_tag
.eq(0)
1255 # Take request from r1.req if there is one there,
1256 # else from req_op, ra, etc.
1258 comb
+= req
.eq(r1
.req
)
1260 comb
+= req
.op
.eq(req_op
)
1261 comb
+= req
.valid
.eq(req_go
)
1262 comb
+= req
.mmu_req
.eq(r0
.mmu_req
)
1263 comb
+= req
.dcbz
.eq(r0
.req
.dcbz
)
1264 comb
+= req
.real_addr
.eq(ra
)
1266 with m
.If(~r0
.req
.dcbz
):
1267 comb
+= req
.data
.eq(r0
.req
.data
)
1269 comb
+= req
.data
.eq(0)
1271 # Select all bytes for dcbz
1272 # and for cacheable loads
1273 with m
.If(r0
.req
.dcbz |
(r0
.req
.load
& ~r0
.req
.nc
)):
1274 comb
+= req
.byte_sel
.eq(~
0) # all 1s
1276 comb
+= req
.byte_sel
.eq(r0
.req
.byte_sel
)
1277 comb
+= req
.hit_way
.eq(req_hit_way
)
1278 comb
+= req
.same_tag
.eq(req_same_tag
)
1280 # Store the incoming request from r0,
1281 # if it is a slow request
1282 # Note that r1.full = 1 implies req_op = OP_NONE
1283 with m
.If((req_op
== Op
.OP_LOAD_MISS
)
1284 |
(req_op
== Op
.OP_LOAD_NC
)
1285 |
(req_op
== Op
.OP_STORE_MISS
)
1286 |
(req_op
== Op
.OP_STORE_HIT
)):
1287 sync
+= r1
.req
.eq(req
)
1288 sync
+= r1
.full
.eq(1)
1290 # Main state machine
1291 with m
.Switch(r1
.state
):
1293 with m
.Case(State
.IDLE
):
1294 sync
+= r1
.real_adr
.eq(req
.real_addr
)
1295 sync
+= r1
.wb
.sel
.eq(req
.byte_sel
)
1296 sync
+= r1
.wb
.dat
.eq(req
.data
)
1297 sync
+= r1
.dcbz
.eq(req
.dcbz
)
1299 # Keep track of our index and way
1300 # for subsequent stores.
1301 sync
+= r1
.store_index
.eq(req_idx
)
1302 sync
+= r1
.store_row
.eq(req_row
)
1303 sync
+= r1
.end_row_ix
.eq(get_row_of_line(req_row
))
1304 sync
+= r1
.reload_tag
.eq(req_tag
)
1305 sync
+= r1
.req
.same_tag
.eq(1)
1307 with m
.If(req
.op
== Op
.OP_STORE_HIT
):
1308 sync
+= r1
.store_way
.eq(req
.hit_way
)
1310 # Reset per-row valid bits,
1311 # ready for handling OP_LOAD_MISS
1312 for i
in range(ROW_PER_LINE
):
1313 sync
+= r1
.rows_valid
[i
].eq(0)
1315 with m
.If(req_op
!= Op
.OP_NONE
):
1316 sync
+= Display("cache op %d", req
.op
)
1318 with m
.Switch(req
.op
):
1319 with m
.Case(Op
.OP_LOAD_HIT
):
1320 # stay in IDLE state
1323 with m
.Case(Op
.OP_LOAD_MISS
):
1324 sync
+= Display("cache miss real addr: %x " \
1326 req
.real_addr
, req_row
, req_tag
)
1328 # Start the wishbone cycle
1329 sync
+= r1
.wb
.we
.eq(0)
1330 sync
+= r1
.wb
.cyc
.eq(1)
1331 sync
+= r1
.wb
.stb
.eq(1)
1333 # Track that we had one request sent
1334 sync
+= r1
.state
.eq(State
.RELOAD_WAIT_ACK
)
1335 sync
+= r1
.write_tag
.eq(1)
1337 with m
.Case(Op
.OP_LOAD_NC
):
1338 sync
+= r1
.wb
.cyc
.eq(1)
1339 sync
+= r1
.wb
.stb
.eq(1)
1340 sync
+= r1
.wb
.we
.eq(0)
1341 sync
+= r1
.state
.eq(State
.NC_LOAD_WAIT_ACK
)
1343 with m
.Case(Op
.OP_STORE_HIT
, Op
.OP_STORE_MISS
):
1344 with m
.If(~req
.dcbz
):
1345 sync
+= r1
.state
.eq(State
.STORE_WAIT_ACK
)
1346 sync
+= r1
.acks_pending
.eq(1)
1347 sync
+= r1
.full
.eq(0)
1348 sync
+= r1
.slow_valid
.eq(1)
1350 with m
.If(~req
.mmu_req
):
1351 sync
+= r1
.ls_valid
.eq(1)
1353 sync
+= r1
.mmu_done
.eq(1)
1355 with m
.If(req
.op
== Op
.OP_STORE_HIT
):
1356 sync
+= r1
.write_bram
.eq(1)
1358 # dcbz is handled much like a load miss except
1359 # that we are writing to memory instead of reading
1360 sync
+= r1
.state
.eq(State
.RELOAD_WAIT_ACK
)
1362 with m
.If(req
.op
== Op
.OP_STORE_MISS
):
1363 sync
+= r1
.write_tag
.eq(1)
1365 sync
+= r1
.wb
.we
.eq(1)
1366 sync
+= r1
.wb
.cyc
.eq(1)
1367 sync
+= r1
.wb
.stb
.eq(1)
1369 # OP_NONE and OP_BAD do nothing
1370 # OP_BAD & OP_STCX_FAIL were
1371 # handled above already
1372 with m
.Case(Op
.OP_NONE
):
1374 with m
.Case(Op
.OP_BAD
):
1376 with m
.Case(Op
.OP_STCX_FAIL
):
1379 with m
.Case(State
.RELOAD_WAIT_ACK
):
1380 ld_stbs_done
= Signal()
1381 # Requests are all sent if stb is 0
1382 comb
+= ld_stbs_done
.eq(~r1
.wb
.stb
)
1384 with m
.If((~wb_in
.stall
) & r1
.wb
.stb
):
1385 # That was the last word?
1386 # We are done sending.
1387 # Clear stb and set ld_stbs_done
1388 # so we can handle an eventual
1389 # last ack on the same cycle.
1390 with m
.If(is_last_row_addr(r1
.real_adr
, r1
.end_row_ix
)):
1391 sync
+= r1
.wb
.stb
.eq(0)
1392 comb
+= ld_stbs_done
.eq(1)
1394 # Calculate the next row address in the current cache line
1395 row
= Signal(LINE_OFF_BITS
-ROW_OFF_BITS
)
1396 comb
+= row
.eq(r1
.real_adr
[ROW_OFF_BITS
:])
1397 sync
+= r1
.real_adr
[ROW_OFF_BITS
:LINE_OFF_BITS
].eq(row
+1)
1399 # Incoming acks processing
1400 sync
+= r1
.forward_valid1
.eq(wb_in
.ack
)
1401 with m
.If(wb_in
.ack
):
1402 srow
= Signal(ROW_LINE_BITS
)
1403 comb
+= srow
.eq(r1
.store_row
)
1404 sync
+= r1
.rows_valid
[srow
].eq(1)
1406 # If this is the data we were looking for,
1407 # we can complete the request next cycle.
1408 # Compare the whole address in case the
1409 # request in r1.req is not the one that
1410 # started this refill.
1411 with m
.If(r1
.full
& r1
.req
.same_tag
&
1412 ((r1
.dcbz
& r1
.req
.dcbz
) |
1413 (~r1
.dcbz
& (r1
.req
.op
== Op
.OP_LOAD_MISS
))) &
1414 (r1
.store_row
== get_row(r1
.req
.real_addr
))):
1415 sync
+= r1
.full
.eq(0)
1416 sync
+= r1
.slow_valid
.eq(1)
1417 with m
.If(~r1
.mmu_req
):
1418 sync
+= r1
.ls_valid
.eq(1)
1420 sync
+= r1
.mmu_done
.eq(1)
1421 sync
+= r1
.forward_sel
.eq(~
0) # all 1s
1422 sync
+= r1
.use_forward1
.eq(1)
1424 # Check for completion
1425 with m
.If(ld_stbs_done
& is_last_row(r1
.store_row
,
1427 # Complete wishbone cycle
1428 sync
+= r1
.wb
.cyc
.eq(0)
1430 # Cache line is now valid
1431 cv
= Signal(INDEX_BITS
)
1432 comb
+= cv
.eq(cache_valids
[r1
.store_index
])
1433 comb
+= cv
.bit_select(r1
.store_way
, 1).eq(1)
1434 sync
+= cache_valids
[r1
.store_index
].eq(cv
)
1435 sync
+= r1
.state
.eq(State
.IDLE
)
1437 # Increment store row counter
1438 sync
+= r1
.store_row
.eq(next_row(r1
.store_row
))
1440 with m
.Case(State
.STORE_WAIT_ACK
):
1441 st_stbs_done
= Signal()
1442 comb
+= st_stbs_done
.eq(~r1
.wb
.stb
)
1443 comb
+= acks
.eq(r1
.acks_pending
)
1445 with m
.If(r1
.inc_acks
!= r1
.dec_acks
):
1446 with m
.If(r1
.inc_acks
):
1447 comb
+= adjust_acks
.eq(acks
+ 1)
1449 comb
+= adjust_acks
.eq(acks
- 1)
1451 comb
+= adjust_acks
.eq(acks
)
1453 sync
+= r1
.acks_pending
.eq(adjust_acks
)
1455 # Clear stb when slave accepted request
1456 with m
.If(~wb_in
.stall
):
1457 # See if there is another store waiting
1458 # to be done which is in the same real page.
1459 with m
.If(req
.valid
):
1460 ra
= req
.real_addr
[0:SET_SIZE_BITS
]
1461 sync
+= r1
.real_adr
[0:SET_SIZE_BITS
].eq(ra
)
1462 sync
+= r1
.wb
.dat
.eq(req
.data
)
1463 sync
+= r1
.wb
.sel
.eq(req
.byte_sel
)
1465 with m
.Elif((adjust_acks
< 7) & req
.same_tag
&
1466 ((req
.op
== Op
.OP_STORE_MISS
)
1467 |
(req
.op
== Op
.OP_STORE_HIT
))):
1468 sync
+= r1
.wb
.stb
.eq(1)
1469 comb
+= st_stbs_done
.eq(0)
1471 with m
.If(req
.op
== Op
.OP_STORE_HIT
):
1472 sync
+= r1
.write_bram
.eq(1)
1473 sync
+= r1
.full
.eq(0)
1474 sync
+= r1
.slow_valid
.eq(1)
1476 # Store requests never come from the MMU
1477 sync
+= r1
.ls_valid
.eq(1)
1478 comb
+= st_stbs_done
.eq(0)
1479 sync
+= r1
.inc_acks
.eq(1)
1481 sync
+= r1
.wb
.stb
.eq(0)
1482 comb
+= st_stbs_done
.eq(1)
1484 # Got ack ? See if complete.
1485 with m
.If(wb_in
.ack
):
1486 with m
.If(st_stbs_done
& (adjust_acks
== 1)):
1487 sync
+= r1
.state
.eq(State
.IDLE
)
1488 sync
+= r1
.wb
.cyc
.eq(0)
1489 sync
+= r1
.wb
.stb
.eq(0)
1490 sync
+= r1
.dec_acks
.eq(1)
1492 with m
.Case(State
.NC_LOAD_WAIT_ACK
):
1493 # Clear stb when slave accepted request
1494 with m
.If(~wb_in
.stall
):
1495 sync
+= r1
.wb
.stb
.eq(0)
1497 # Got ack ? complete.
1498 with m
.If(wb_in
.ack
):
1499 sync
+= r1
.state
.eq(State
.IDLE
)
1500 sync
+= r1
.full
.eq(0)
1501 sync
+= r1
.slow_valid
.eq(1)
1503 with m
.If(~r1
.mmu_req
):
1504 sync
+= r1
.ls_valid
.eq(1)
1506 sync
+= r1
.mmu_done
.eq(1)
1508 sync
+= r1
.forward_sel
.eq(~
0) # all 1s
1509 sync
+= r1
.use_forward1
.eq(1)
1510 sync
+= r1
.wb
.cyc
.eq(0)
1511 sync
+= r1
.wb
.stb
.eq(0)
1513 def dcache_log(self
, m
, r1
, valid_ra
, tlb_hit_way
, stall_out
):
1516 d_out
, wb_in
, log_out
= self
.d_out
, self
.wb_in
, self
.log_out
1518 sync
+= log_out
.eq(Cat(r1
.state
[:3], valid_ra
, tlb_hit_way
[:3],
1519 stall_out
, req_op
[:3], d_out
.valid
, d_out
.error
,
1520 r1
.wb
.cyc
, r1
.wb
.stb
, wb_in
.ack
, wb_in
.stall
,
1523 def elaborate(self
, platform
):
1528 # Storage. Hopefully "cache_rows" is a BRAM, the rest is LUTs
1529 cache_tags
= CacheTagArray()
1530 cache_tag_set
= Signal(TAG_RAM_WIDTH
)
1531 cache_valids
= CacheValidBitsArray()
1533 # TODO attribute ram_style : string;
1534 # TODO attribute ram_style of cache_tags : signal is "distributed";
1536 """note: these are passed to nmigen.hdl.Memory as "attributes".
1537 don't know how, just that they are.
1539 dtlb_valid_bits
= TLBValidBitsArray()
1540 dtlb_tags
= TLBTagsArray()
1541 dtlb_ptes
= TLBPtesArray()
1542 # TODO attribute ram_style of
1543 # dtlb_tags : signal is "distributed";
1544 # TODO attribute ram_style of
1545 # dtlb_ptes : signal is "distributed";
1547 r0
= RegStage0("r0")
1550 r1
= RegStage1("r1")
1552 reservation
= Reservation()
1554 # Async signals on incoming request
1555 req_index
= Signal(INDEX_BITS
)
1556 req_row
= Signal(ROW_BITS
)
1557 req_hit_way
= Signal(WAY_BITS
)
1558 req_tag
= Signal(TAG_BITS
)
1560 req_data
= Signal(64)
1561 req_same_tag
= Signal()
1564 early_req_row
= Signal(ROW_BITS
)
1566 cancel_store
= Signal()
1568 clear_rsrv
= Signal()
1573 use_forward1_next
= Signal()
1574 use_forward2_next
= Signal()
1576 cache_out
= CacheRamOut()
1578 plru_victim
= PLRUOut()
1579 replace_way
= Signal(WAY_BITS
)
1581 # Wishbone read/write/cache write formatting signals
1585 tlb_tag_way
= Signal(TLB_TAG_WAY_BITS
)
1586 tlb_pte_way
= Signal(TLB_PTE_WAY_BITS
)
1587 tlb_valid_way
= Signal(TLB_NUM_WAYS
)
1588 tlb_req_index
= Signal(TLB_SET_BITS
)
1590 tlb_hit_way
= Signal(TLB_WAY_BITS
)
1591 pte
= Signal(TLB_PTE_BITS
)
1592 ra
= Signal(REAL_ADDR_BITS
)
1594 perm_attr
= PermAttr("dc_perms")
1597 access_ok
= Signal()
1599 tlb_plru_victim
= TLBPLRUOut()
1601 # we don't yet handle collisions between loadstore1 requests
1603 comb
+= self
.m_out
.stall
.eq(0)
1605 # Hold off the request in r0 when r1 has an uncompleted request
1606 comb
+= r0_stall
.eq(r0_full
& r1
.full
)
1607 comb
+= r0_valid
.eq(r0_full
& ~r1
.full
)
1608 comb
+= self
.stall_out
.eq(r0_stall
)
1610 # Wire up wishbone request latch out of stage 1
1611 comb
+= r1
.wb
.adr
.eq(r1
.real_adr
[ROW_OFF_BITS
:]) # truncate LSBs
1612 comb
+= self
.wb_out
.eq(r1
.wb
)
1614 # call sub-functions putting everything together, using shared
1615 # signals established above
1616 self
.stage_0(m
, r0
, r1
, r0_full
)
1617 self
.tlb_read(m
, r0_stall
, tlb_valid_way
,
1618 tlb_tag_way
, tlb_pte_way
, dtlb_valid_bits
,
1619 dtlb_tags
, dtlb_ptes
)
1620 self
.tlb_search(m
, tlb_req_index
, r0
, r0_valid
,
1621 tlb_valid_way
, tlb_tag_way
, tlb_hit_way
,
1622 tlb_pte_way
, pte
, tlb_hit
, valid_ra
, perm_attr
, ra
)
1623 self
.tlb_update(m
, r0_valid
, r0
, dtlb_valid_bits
, tlb_req_index
,
1624 tlb_hit_way
, tlb_hit
, tlb_plru_victim
, tlb_tag_way
,
1625 dtlb_tags
, tlb_pte_way
, dtlb_ptes
)
1626 self
.maybe_plrus(m
, r1
, plru_victim
)
1627 self
.maybe_tlb_plrus(m
, r1
, tlb_plru_victim
)
1628 self
.cache_tag_read(m
, r0_stall
, req_index
, cache_tag_set
, cache_tags
)
1629 self
.dcache_request(m
, r0
, ra
, req_index
, req_row
, req_tag
,
1630 r0_valid
, r1
, cache_valids
, replace_way
,
1631 use_forward1_next
, use_forward2_next
,
1632 req_hit_way
, plru_victim
, rc_ok
, perm_attr
,
1633 valid_ra
, perm_ok
, access_ok
, req_op
, req_go
,
1635 tlb_hit
, tlb_hit_way
, tlb_valid_way
, cache_tag_set
,
1636 cancel_store
, req_same_tag
, r0_stall
, early_req_row
)
1637 self
.reservation_comb(m
, cancel_store
, set_rsrv
, clear_rsrv
,
1638 r0_valid
, r0
, reservation
)
1639 self
.reservation_reg(m
, r0_valid
, access_ok
, set_rsrv
, clear_rsrv
,
1641 self
.writeback_control(m
, r1
, cache_out
)
1642 self
.rams(m
, r1
, early_req_row
, cache_out
, replace_way
)
1643 self
.dcache_fast_hit(m
, req_op
, r0_valid
, r0
, r1
,
1644 req_hit_way
, req_index
, req_tag
, access_ok
,
1645 tlb_hit
, tlb_hit_way
, tlb_req_index
)
1646 self
.dcache_slow(m
, r1
, use_forward1_next
, use_forward2_next
,
1647 cache_valids
, r0
, replace_way
,
1648 req_hit_way
, req_same_tag
,
1649 r0_valid
, req_op
, cache_tags
, req_go
, ra
)
1650 #self.dcache_log(m, r1, valid_ra, tlb_hit_way, stall_out)
1654 def dcache_load(dut
, addr
, nc
=0):
1655 yield dut
.d_in
.load
.eq(1)
1656 yield dut
.d_in
.nc
.eq(nc
)
1657 yield dut
.d_in
.addr
.eq(addr
)
1658 yield dut
.d_in
.byte_sel
.eq(~
0)
1659 yield dut
.d_in
.valid
.eq(1)
1661 yield dut
.d_in
.valid
.eq(0)
1662 yield dut
.d_in
.byte_sel
.eq(0)
1664 while not (yield dut
.d_out
.valid
):
1666 data
= yield dut
.d_out
.data
1670 def dcache_store(dut
, addr
, data
, nc
=0):
1671 yield dut
.d_in
.load
.eq(0)
1672 yield dut
.d_in
.nc
.eq(nc
)
1673 yield dut
.d_in
.data
.eq(data
)
1674 yield dut
.d_in
.byte_sel
.eq(~
0)
1675 yield dut
.d_in
.addr
.eq(addr
)
1676 yield dut
.d_in
.valid
.eq(1)
1678 yield dut
.d_in
.valid
.eq(0)
1679 yield dut
.d_in
.byte_sel
.eq(0)
1681 while not (yield dut
.d_out
.valid
):
1685 def dcache_random_sim(dut
):
1687 # start with stack of zeros
1691 yield dut
.d_in
.valid
.eq(0)
1692 yield dut
.d_in
.load
.eq(0)
1693 yield dut
.d_in
.priv_mode
.eq(1)
1694 yield dut
.d_in
.nc
.eq(0)
1695 yield dut
.d_in
.addr
.eq(0)
1696 yield dut
.d_in
.data
.eq(0)
1697 yield dut
.m_in
.valid
.eq(0)
1698 yield dut
.m_in
.addr
.eq(0)
1699 yield dut
.m_in
.pte
.eq(0)
1700 # wait 4 * clk_period
1708 for i
in range(256):
1709 addr
= randint(0, 255)
1710 data
= randint(0, (1<<64)-1)
1711 sim_mem
[addr
] = data
1714 print ("testing %x data %x" % (addr
, data
))
1716 yield from dcache_load(dut
, addr
)
1717 yield from dcache_store(dut
, addr
, data
)
1719 addr
= randint(0, 255)
1720 sim_data
= sim_mem
[addr
]
1723 data
= yield from dcache_load(dut
, addr
)
1724 assert data
== sim_data
, \
1725 "check %x data %x != %x" % (addr
, data
, sim_data
)
1727 for addr
in range(256):
1728 data
= yield from dcache_load(dut
, addr
*8)
1729 assert data
== sim_mem
[addr
], \
1730 "final check %x data %x != %x" % (addr
*8, data
, sim_mem
[addr
])
1732 def dcache_sim(dut
):
1734 yield dut
.d_in
.valid
.eq(0)
1735 yield dut
.d_in
.load
.eq(0)
1736 yield dut
.d_in
.priv_mode
.eq(1)
1737 yield dut
.d_in
.nc
.eq(0)
1738 yield dut
.d_in
.addr
.eq(0)
1739 yield dut
.d_in
.data
.eq(0)
1740 yield dut
.m_in
.valid
.eq(0)
1741 yield dut
.m_in
.addr
.eq(0)
1742 yield dut
.m_in
.pte
.eq(0)
1743 # wait 4 * clk_period
1749 # Cacheable read of address 4
1750 data
= yield from dcache_load(dut
, 0x58)
1751 addr
= yield dut
.d_in
.addr
1752 assert data
== 0x0000001700000016, \
1753 f
"data @%x=%x expected 0x0000001700000016" % (addr
, data
)
1755 # Cacheable read of address 20
1756 data
= yield from dcache_load(dut
, 0x20)
1757 addr
= yield dut
.d_in
.addr
1758 assert data
== 0x0000000900000008, \
1759 f
"data @%x=%x expected 0x0000000900000008" % (addr
, data
)
1761 # Cacheable read of address 30
1762 data
= yield from dcache_load(dut
, 0x530)
1763 addr
= yield dut
.d_in
.addr
1764 assert data
== 0x0000014D0000014C, \
1765 f
"data @%x=%x expected 0000014D0000014C" % (addr
, data
)
1767 # 2nd Cacheable read of address 30
1768 data
= yield from dcache_load(dut
, 0x530)
1769 addr
= yield dut
.d_in
.addr
1770 assert data
== 0x0000014D0000014C, \
1771 f
"data @%x=%x expected 0000014D0000014C" % (addr
, data
)
1773 # Non-cacheable read of address 100
1774 data
= yield from dcache_load(dut
, 0x100, nc
=1)
1775 addr
= yield dut
.d_in
.addr
1776 assert data
== 0x0000004100000040, \
1777 f
"data @%x=%x expected 0000004100000040" % (addr
, data
)
1779 # Store at address 530
1780 yield from dcache_store(dut
, 0x530, 0x121)
1782 # Store at address 30
1783 yield from dcache_store(dut
, 0x530, 0x12345678)
1785 # 3nd Cacheable read of address 530
1786 data
= yield from dcache_load(dut
, 0x530)
1787 addr
= yield dut
.d_in
.addr
1788 assert data
== 0x12345678, \
1789 f
"data @%x=%x expected 0x12345678" % (addr
, data
)
1791 # 4th Cacheable read of address 20
1792 data
= yield from dcache_load(dut
, 0x20)
1793 addr
= yield dut
.d_in
.addr
1794 assert data
== 0x0000000900000008, \
1795 f
"data @%x=%x expected 0x0000000900000008" % (addr
, data
)
1803 def test_dcache(mem
, test_fn
, test_name
):
1806 memory
= Memory(width
=64, depth
=16*64, init
=mem
)
1807 sram
= SRAM(memory
=memory
, granularity
=8)
1810 m
.submodules
.dcache
= dut
1811 m
.submodules
.sram
= sram
1813 m
.d
.comb
+= sram
.bus
.cyc
.eq(dut
.wb_out
.cyc
)
1814 m
.d
.comb
+= sram
.bus
.stb
.eq(dut
.wb_out
.stb
)
1815 m
.d
.comb
+= sram
.bus
.we
.eq(dut
.wb_out
.we
)
1816 m
.d
.comb
+= sram
.bus
.sel
.eq(dut
.wb_out
.sel
)
1817 m
.d
.comb
+= sram
.bus
.adr
.eq(dut
.wb_out
.adr
)
1818 m
.d
.comb
+= sram
.bus
.dat_w
.eq(dut
.wb_out
.dat
)
1820 m
.d
.comb
+= dut
.wb_in
.ack
.eq(sram
.bus
.ack
)
1821 m
.d
.comb
+= dut
.wb_in
.dat
.eq(sram
.bus
.dat_r
)
1827 sim
.add_sync_process(wrap(test_fn(dut
)))
1828 with sim
.write_vcd('test_dcache%s.vcd' % test_name
):
1831 if __name__
== '__main__':
1833 vl
= rtlil
.convert(dut
, ports
=[])
1834 with
open("test_dcache.il", "w") as f
:
1838 for i
in range(0,512):
1839 mem
.append((i
*2)|
((i
*2+1)<<32))
1841 test_dcache(mem
, dcache_sim
, "")
1842 test_dcache(None, dcache_random_sim
, "random")