replace PartitionedSignal with SimdSignal
[soc.git] / src / soc / experiment / dcache.py
1 """DCache
2
3 based on Anton Blanchard microwatt dcache.vhdl
4
5 note that the microwatt dcache wishbone interface expects "stall".
6 for simplicity at the moment this is hard-coded to cyc & ~ack.
7 see WB4 spec, p84, section 5.2.1
8
9 IMPORTANT: for store, the data is sampled the cycle AFTER the "valid"
10 is raised. sigh
11
12 Links:
13
14 * https://libre-soc.org/3d_gpu/architecture/set_associative_cache.jpg
15 * https://bugs.libre-soc.org/show_bug.cgi?id=469
16
17 """
18
19 import sys
20
21 from nmutil.gtkw import write_gtkw
22
23 sys.setrecursionlimit(1000000)
24
25 from enum import Enum, unique
26
27 from nmigen import Module, Signal, Elaboratable, Cat, Repl, Array, Const
28 from nmutil.util import Display
29
30 from copy import deepcopy
31 from random import randint, seed
32
33 from nmigen.cli import main
34 from nmutil.iocontrol import RecordObject
35 from nmigen.utils import log2_int
36 from soc.experiment.mem_types import (LoadStore1ToDCacheType,
37 DCacheToLoadStore1Type,
38 MMUToDCacheType,
39 DCacheToMMUType)
40
41 from soc.experiment.wb_types import (WB_ADDR_BITS, WB_DATA_BITS, WB_SEL_BITS,
42 WBAddrType, WBDataType, WBSelType,
43 WBMasterOut, WBSlaveOut,
44 WBMasterOutVector, WBSlaveOutVector,
45 WBIOMasterOut, WBIOSlaveOut)
46
47 from soc.experiment.cache_ram import CacheRam
48 #from soc.experiment.plru import PLRU
49 from nmutil.plru import PLRU
50
51 # for test
52 from soc.bus.sram import SRAM
53 from nmigen import Memory
54 from nmigen.cli import rtlil
55
56 # NOTE: to use cxxsim, export NMIGEN_SIM_MODE=cxxsim from the shell
57 # Also, check out the cxxsim nmigen branch, and latest yosys from git
58 from nmutil.sim_tmp_alternative import Simulator
59
60 from nmutil.util import wrap
61
62
63 # TODO: make these parameters of DCache at some point
64 LINE_SIZE = 64 # Line size in bytes
65 NUM_LINES = 16 # Number of lines in a set
66 NUM_WAYS = 4 # Number of ways
67 TLB_SET_SIZE = 64 # L1 DTLB entries per set
68 TLB_NUM_WAYS = 2 # L1 DTLB number of sets
69 TLB_LG_PGSZ = 12 # L1 DTLB log_2(page_size)
70 LOG_LENGTH = 0 # Non-zero to enable log data collection
71
72 # BRAM organisation: We never access more than
73 # -- WB_DATA_BITS at a time so to save
74 # -- resources we make the array only that wide, and
75 # -- use consecutive indices for to make a cache "line"
76 # --
77 # -- ROW_SIZE is the width in bytes of the BRAM
78 # -- (based on WB, so 64-bits)
79 ROW_SIZE = WB_DATA_BITS // 8;
80
81 # ROW_PER_LINE is the number of row (wishbone
82 # transactions) in a line
83 ROW_PER_LINE = LINE_SIZE // ROW_SIZE
84
85 # BRAM_ROWS is the number of rows in BRAM needed
86 # to represent the full dcache
87 BRAM_ROWS = NUM_LINES * ROW_PER_LINE
88
89 print ("ROW_SIZE", ROW_SIZE)
90 print ("ROW_PER_LINE", ROW_PER_LINE)
91 print ("BRAM_ROWS", BRAM_ROWS)
92 print ("NUM_WAYS", NUM_WAYS)
93
94 # Bit fields counts in the address
95
96 # REAL_ADDR_BITS is the number of real address
97 # bits that we store
98 REAL_ADDR_BITS = 56
99
100 # ROW_BITS is the number of bits to select a row
101 ROW_BITS = log2_int(BRAM_ROWS)
102
103 # ROW_LINE_BITS is the number of bits to select
104 # a row within a line
105 ROW_LINE_BITS = log2_int(ROW_PER_LINE)
106
107 # LINE_OFF_BITS is the number of bits for
108 # the offset in a cache line
109 LINE_OFF_BITS = log2_int(LINE_SIZE)
110
111 # ROW_OFF_BITS is the number of bits for
112 # the offset in a row
113 ROW_OFF_BITS = log2_int(ROW_SIZE)
114
115 # INDEX_BITS is the number if bits to
116 # select a cache line
117 INDEX_BITS = log2_int(NUM_LINES)
118
119 # SET_SIZE_BITS is the log base 2 of the set size
120 SET_SIZE_BITS = LINE_OFF_BITS + INDEX_BITS
121
122 # TAG_BITS is the number of bits of
123 # the tag part of the address
124 TAG_BITS = REAL_ADDR_BITS - SET_SIZE_BITS
125
126 # TAG_WIDTH is the width in bits of each way of the tag RAM
127 TAG_WIDTH = TAG_BITS + 7 - ((TAG_BITS + 7) % 8)
128
129 # WAY_BITS is the number of bits to select a way
130 WAY_BITS = log2_int(NUM_WAYS)
131
132 # Example of layout for 32 lines of 64 bytes:
133 layout = """\
134 .. tag |index| line |
135 .. | row | |
136 .. | |---| | ROW_LINE_BITS (3)
137 .. | |--- - --| LINE_OFF_BITS (6)
138 .. | |- --| ROW_OFF_BITS (3)
139 .. |----- ---| | ROW_BITS (8)
140 .. |-----| | INDEX_BITS (5)
141 .. --------| | TAG_BITS (45)
142 """
143 print (layout)
144 print ("Dcache TAG %d IDX %d ROW_BITS %d ROFF %d LOFF %d RLB %d" % \
145 (TAG_BITS, INDEX_BITS, ROW_BITS,
146 ROW_OFF_BITS, LINE_OFF_BITS, ROW_LINE_BITS))
147 print ("index @: %d-%d" % (LINE_OFF_BITS, SET_SIZE_BITS))
148 print ("row @: %d-%d" % (LINE_OFF_BITS, ROW_OFF_BITS))
149 print ("tag @: %d-%d width %d" % (SET_SIZE_BITS, REAL_ADDR_BITS, TAG_WIDTH))
150
151 TAG_RAM_WIDTH = TAG_WIDTH * NUM_WAYS
152
153 print ("TAG_RAM_WIDTH", TAG_RAM_WIDTH)
154
155 def CacheTagArray():
156 return Array(Signal(TAG_RAM_WIDTH, name="cachetag_%d" % x) \
157 for x in range(NUM_LINES))
158
159 def CacheValidBitsArray():
160 return Array(Signal(NUM_WAYS, name="cachevalid_%d" % x) \
161 for x in range(NUM_LINES))
162
163 def RowPerLineValidArray():
164 return Array(Signal(name="rows_valid%d" % x) \
165 for x in range(ROW_PER_LINE))
166
167 # L1 TLB
168 TLB_SET_BITS = log2_int(TLB_SET_SIZE)
169 TLB_WAY_BITS = log2_int(TLB_NUM_WAYS)
170 TLB_EA_TAG_BITS = 64 - (TLB_LG_PGSZ + TLB_SET_BITS)
171 TLB_TAG_WAY_BITS = TLB_NUM_WAYS * TLB_EA_TAG_BITS
172 TLB_PTE_BITS = 64
173 TLB_PTE_WAY_BITS = TLB_NUM_WAYS * TLB_PTE_BITS;
174
175 def ispow2(x):
176 return (1<<log2_int(x, False)) == x
177
178 assert (LINE_SIZE % ROW_SIZE) == 0, "LINE_SIZE not multiple of ROW_SIZE"
179 assert ispow2(LINE_SIZE), "LINE_SIZE not power of 2"
180 assert ispow2(NUM_LINES), "NUM_LINES not power of 2"
181 assert ispow2(ROW_PER_LINE), "ROW_PER_LINE not power of 2"
182 assert ROW_BITS == (INDEX_BITS + ROW_LINE_BITS), "geometry bits don't add up"
183 assert (LINE_OFF_BITS == ROW_OFF_BITS + ROW_LINE_BITS), \
184 "geometry bits don't add up"
185 assert REAL_ADDR_BITS == (TAG_BITS + INDEX_BITS + LINE_OFF_BITS), \
186 "geometry bits don't add up"
187 assert REAL_ADDR_BITS == (TAG_BITS + ROW_BITS + ROW_OFF_BITS), \
188 "geometry bits don't add up"
189 assert 64 == WB_DATA_BITS, "Can't yet handle wb width that isn't 64-bits"
190 assert SET_SIZE_BITS <= TLB_LG_PGSZ, "Set indexed by virtual address"
191
192
193 def TLBValidBitsArray():
194 return Array(Signal(TLB_NUM_WAYS, name="tlbvalid%d" % x) \
195 for x in range(TLB_SET_SIZE))
196
197 def TLBTagEAArray():
198 return Array(Signal(TLB_EA_TAG_BITS, name="tlbtagea%d" % x) \
199 for x in range (TLB_NUM_WAYS))
200
201 def TLBTagsArray():
202 return Array(Signal(TLB_TAG_WAY_BITS, name="tlbtags%d" % x) \
203 for x in range (TLB_SET_SIZE))
204
205 def TLBPtesArray():
206 return Array(Signal(TLB_PTE_WAY_BITS, name="tlbptes%d" % x) \
207 for x in range(TLB_SET_SIZE))
208
209 def HitWaySet():
210 return Array(Signal(WAY_BITS, name="hitway_%d" % x) \
211 for x in range(TLB_NUM_WAYS))
212
213 # Cache RAM interface
214 def CacheRamOut():
215 return Array(Signal(WB_DATA_BITS, name="cache_out%d" % x) \
216 for x in range(NUM_WAYS))
217
218 # PLRU output interface
219 def PLRUOut():
220 return Array(Signal(WAY_BITS, name="plru_out%d" % x) \
221 for x in range(NUM_LINES))
222
223 # TLB PLRU output interface
224 def TLBPLRUOut():
225 return Array(Signal(TLB_WAY_BITS, name="tlbplru_out%d" % x) \
226 for x in range(TLB_SET_SIZE))
227
228 # Helper functions to decode incoming requests
229 #
230 # Return the cache line index (tag index) for an address
231 def get_index(addr):
232 return addr[LINE_OFF_BITS:SET_SIZE_BITS]
233
234 # Return the cache row index (data memory) for an address
235 def get_row(addr):
236 return addr[ROW_OFF_BITS:SET_SIZE_BITS]
237
238 # Return the index of a row within a line
239 def get_row_of_line(row):
240 return row[:ROW_BITS][:ROW_LINE_BITS]
241
242 # Returns whether this is the last row of a line
243 def is_last_row_addr(addr, last):
244 return addr[ROW_OFF_BITS:LINE_OFF_BITS] == last
245
246 # Returns whether this is the last row of a line
247 def is_last_row(row, last):
248 return get_row_of_line(row) == last
249
250 # Return the next row in the current cache line. We use a
251 # dedicated function in order to limit the size of the
252 # generated adder to be only the bits within a cache line
253 # (3 bits with default settings)
254 def next_row(row):
255 row_v = row[0:ROW_LINE_BITS] + 1
256 return Cat(row_v[:ROW_LINE_BITS], row[ROW_LINE_BITS:])
257
258 # Get the tag value from the address
259 def get_tag(addr):
260 return addr[SET_SIZE_BITS:REAL_ADDR_BITS]
261
262 # Read a tag from a tag memory row
263 def read_tag(way, tagset):
264 return tagset.word_select(way, TAG_WIDTH)[:TAG_BITS]
265
266 # Read a TLB tag from a TLB tag memory row
267 def read_tlb_tag(way, tags):
268 return tags.word_select(way, TLB_EA_TAG_BITS)
269
270 # Write a TLB tag to a TLB tag memory row
271 def write_tlb_tag(way, tags, tag):
272 return read_tlb_tag(way, tags).eq(tag)
273
274 # Read a PTE from a TLB PTE memory row
275 def read_tlb_pte(way, ptes):
276 return ptes.word_select(way, TLB_PTE_BITS)
277
278 def write_tlb_pte(way, ptes, newpte):
279 return read_tlb_pte(way, ptes).eq(newpte)
280
281
282 # Record for storing permission, attribute, etc. bits from a PTE
283 class PermAttr(RecordObject):
284 def __init__(self, name=None):
285 super().__init__(name=name)
286 self.reference = Signal()
287 self.changed = Signal()
288 self.nocache = Signal()
289 self.priv = Signal()
290 self.rd_perm = Signal()
291 self.wr_perm = Signal()
292
293
294 def extract_perm_attr(pte):
295 pa = PermAttr()
296 return pa;
297
298
299 # Type of operation on a "valid" input
300 @unique
301 class Op(Enum):
302 OP_NONE = 0
303 OP_BAD = 1 # NC cache hit, TLB miss, prot/RC failure
304 OP_STCX_FAIL = 2 # conditional store w/o reservation
305 OP_LOAD_HIT = 3 # Cache hit on load
306 OP_LOAD_MISS = 4 # Load missing cache
307 OP_LOAD_NC = 5 # Non-cachable load
308 OP_STORE_HIT = 6 # Store hitting cache
309 OP_STORE_MISS = 7 # Store missing cache
310
311
312 # Cache state machine
313 @unique
314 class State(Enum):
315 IDLE = 0 # Normal load hit processing
316 RELOAD_WAIT_ACK = 1 # Cache reload wait ack
317 STORE_WAIT_ACK = 2 # Store wait ack
318 NC_LOAD_WAIT_ACK = 3 # Non-cachable load wait ack
319
320
321 # Dcache operations:
322 #
323 # In order to make timing, we use the BRAMs with
324 # an output buffer, which means that the BRAM
325 # output is delayed by an extra cycle.
326 #
327 # Thus, the dcache has a 2-stage internal pipeline
328 # for cache hits with no stalls.
329 #
330 # All other operations are handled via stalling
331 # in the first stage.
332 #
333 # The second stage can thus complete a hit at the same
334 # time as the first stage emits a stall for a complex op.
335 #
336 # Stage 0 register, basically contains just the latched request
337
338 class RegStage0(RecordObject):
339 def __init__(self, name=None):
340 super().__init__(name=name)
341 self.req = LoadStore1ToDCacheType(name="lsmem")
342 self.tlbie = Signal() # indicates a tlbie request (from MMU)
343 self.doall = Signal() # with tlbie, indicates flush whole TLB
344 self.tlbld = Signal() # indicates a TLB load request (from MMU)
345 self.mmu_req = Signal() # indicates source of request
346 self.d_valid = Signal() # indicates req.data is valid now
347
348
349 class MemAccessRequest(RecordObject):
350 def __init__(self, name=None):
351 super().__init__(name=name)
352 self.op = Signal(Op)
353 self.valid = Signal()
354 self.dcbz = Signal()
355 self.real_addr = Signal(REAL_ADDR_BITS)
356 self.data = Signal(64)
357 self.byte_sel = Signal(8)
358 self.hit_way = Signal(WAY_BITS)
359 self.same_tag = Signal()
360 self.mmu_req = Signal()
361
362
363 # First stage register, contains state for stage 1 of load hits
364 # and for the state machine used by all other operations
365 class RegStage1(RecordObject):
366 def __init__(self, name=None):
367 super().__init__(name=name)
368 # Info about the request
369 self.full = Signal() # have uncompleted request
370 self.mmu_req = Signal() # request is from MMU
371 self.req = MemAccessRequest(name="reqmem")
372
373 # Cache hit state
374 self.hit_way = Signal(WAY_BITS)
375 self.hit_load_valid = Signal()
376 self.hit_index = Signal(INDEX_BITS)
377 self.cache_hit = Signal()
378
379 # TLB hit state
380 self.tlb_hit = Signal()
381 self.tlb_hit_way = Signal(TLB_NUM_WAYS)
382 self.tlb_hit_index = Signal(TLB_WAY_BITS)
383
384 # 2-stage data buffer for data forwarded from writes to reads
385 self.forward_data1 = Signal(64)
386 self.forward_data2 = Signal(64)
387 self.forward_sel1 = Signal(8)
388 self.forward_valid1 = Signal()
389 self.forward_way1 = Signal(WAY_BITS)
390 self.forward_row1 = Signal(ROW_BITS)
391 self.use_forward1 = Signal()
392 self.forward_sel = Signal(8)
393
394 # Cache miss state (reload state machine)
395 self.state = Signal(State)
396 self.dcbz = Signal()
397 self.write_bram = Signal()
398 self.write_tag = Signal()
399 self.slow_valid = Signal()
400 self.wb = WBMasterOut("wb")
401 self.reload_tag = Signal(TAG_BITS)
402 self.store_way = Signal(WAY_BITS)
403 self.store_row = Signal(ROW_BITS)
404 self.store_index = Signal(INDEX_BITS)
405 self.end_row_ix = Signal(ROW_LINE_BITS)
406 self.rows_valid = RowPerLineValidArray()
407 self.acks_pending = Signal(3)
408 self.inc_acks = Signal()
409 self.dec_acks = Signal()
410
411 # Signals to complete (possibly with error)
412 self.ls_valid = Signal()
413 self.ls_error = Signal()
414 self.mmu_done = Signal()
415 self.mmu_error = Signal()
416 self.cache_paradox = Signal()
417
418 # Signal to complete a failed stcx.
419 self.stcx_fail = Signal()
420
421
422 # Reservation information
423 class Reservation(RecordObject):
424 def __init__(self):
425 super().__init__()
426 self.valid = Signal()
427 self.addr = Signal(64-LINE_OFF_BITS)
428
429
430 class DTLBUpdate(Elaboratable):
431 def __init__(self):
432 self.tlbie = Signal()
433 self.tlbwe = Signal()
434 self.doall = Signal()
435 self.updated = Signal()
436 self.v_updated = Signal()
437 self.tlb_hit = Signal()
438 self.tlb_req_index = Signal(TLB_SET_BITS)
439
440 self.tlb_hit_way = Signal(TLB_WAY_BITS)
441 self.tlb_tag_way = Signal(TLB_TAG_WAY_BITS)
442 self.tlb_pte_way = Signal(TLB_PTE_WAY_BITS)
443 self.repl_way = Signal(TLB_WAY_BITS)
444 self.eatag = Signal(TLB_EA_TAG_BITS)
445 self.pte_data = Signal(TLB_PTE_BITS)
446
447 self.dv = Signal(TLB_NUM_WAYS) # tlb_way_valids_t
448
449 self.tb_out = Signal(TLB_TAG_WAY_BITS) # tlb_way_tags_t
450 self.db_out = Signal(TLB_NUM_WAYS) # tlb_way_valids_t
451 self.pb_out = Signal(TLB_PTE_WAY_BITS) # tlb_way_ptes_t
452
453 def elaborate(self, platform):
454 m = Module()
455 comb = m.d.comb
456 sync = m.d.sync
457
458 tagset = Signal(TLB_TAG_WAY_BITS)
459 pteset = Signal(TLB_PTE_WAY_BITS)
460
461 tb_out, pb_out, db_out = self.tb_out, self.pb_out, self.db_out
462 comb += db_out.eq(self.dv)
463
464 with m.If(self.tlbie & self.doall):
465 pass # clear all back in parent
466 with m.Elif(self.tlbie):
467 with m.If(self.tlb_hit):
468 comb += db_out.bit_select(self.tlb_hit_way, 1).eq(0)
469 comb += self.v_updated.eq(1)
470
471 with m.Elif(self.tlbwe):
472
473 comb += tagset.eq(self.tlb_tag_way)
474 comb += write_tlb_tag(self.repl_way, tagset, self.eatag)
475 comb += tb_out.eq(tagset)
476
477 comb += pteset.eq(self.tlb_pte_way)
478 comb += write_tlb_pte(self.repl_way, pteset, self.pte_data)
479 comb += pb_out.eq(pteset)
480
481 comb += db_out.bit_select(self.repl_way, 1).eq(1)
482
483 comb += self.updated.eq(1)
484 comb += self.v_updated.eq(1)
485
486 return m
487
488
489 class DCachePendingHit(Elaboratable):
490
491 def __init__(self, tlb_pte_way, tlb_valid_way, tlb_hit_way,
492 cache_i_validdx, cache_tag_set,
493 req_addr,
494 hit_set):
495
496 self.go = Signal()
497 self.virt_mode = Signal()
498 self.is_hit = Signal()
499 self.tlb_hit = Signal()
500 self.hit_way = Signal(WAY_BITS)
501 self.rel_match = Signal()
502 self.req_index = Signal(INDEX_BITS)
503 self.reload_tag = Signal(TAG_BITS)
504
505 self.tlb_hit_way = tlb_hit_way
506 self.tlb_pte_way = tlb_pte_way
507 self.tlb_valid_way = tlb_valid_way
508 self.cache_i_validdx = cache_i_validdx
509 self.cache_tag_set = cache_tag_set
510 self.req_addr = req_addr
511 self.hit_set = hit_set
512
513 def elaborate(self, platform):
514 m = Module()
515 comb = m.d.comb
516 sync = m.d.sync
517
518 go = self.go
519 virt_mode = self.virt_mode
520 is_hit = self.is_hit
521 tlb_pte_way = self.tlb_pte_way
522 tlb_valid_way = self.tlb_valid_way
523 cache_i_validdx = self.cache_i_validdx
524 cache_tag_set = self.cache_tag_set
525 req_addr = self.req_addr
526 tlb_hit_way = self.tlb_hit_way
527 tlb_hit = self.tlb_hit
528 hit_set = self.hit_set
529 hit_way = self.hit_way
530 rel_match = self.rel_match
531 req_index = self.req_index
532 reload_tag = self.reload_tag
533
534 rel_matches = Array(Signal(name="rel_matches_%d" % i) \
535 for i in range(TLB_NUM_WAYS))
536 hit_way_set = HitWaySet()
537
538 # Test if pending request is a hit on any way
539 # In order to make timing in virtual mode,
540 # when we are using the TLB, we compare each
541 # way with each of the real addresses from each way of
542 # the TLB, and then decide later which match to use.
543
544 with m.If(virt_mode):
545 for j in range(TLB_NUM_WAYS): # tlb_num_way_t
546 s_tag = Signal(TAG_BITS, name="s_tag%d" % j)
547 s_hit = Signal()
548 s_pte = Signal(TLB_PTE_BITS)
549 s_ra = Signal(REAL_ADDR_BITS)
550 comb += s_pte.eq(read_tlb_pte(j, tlb_pte_way))
551 comb += s_ra.eq(Cat(req_addr[0:TLB_LG_PGSZ],
552 s_pte[TLB_LG_PGSZ:REAL_ADDR_BITS]))
553 comb += s_tag.eq(get_tag(s_ra))
554
555 for i in range(NUM_WAYS): # way_t
556 is_tag_hit = Signal(name="is_tag_hit_%d_%d" % (j, i))
557 comb += is_tag_hit.eq(go & cache_i_validdx[i] &
558 (read_tag(i, cache_tag_set) == s_tag)
559 & tlb_valid_way[j])
560 with m.If(is_tag_hit):
561 comb += hit_way_set[j].eq(i)
562 comb += s_hit.eq(1)
563 comb += hit_set[j].eq(s_hit)
564 with m.If(s_tag == reload_tag):
565 comb += rel_matches[j].eq(1)
566 with m.If(tlb_hit):
567 comb += is_hit.eq(hit_set[tlb_hit_way])
568 comb += hit_way.eq(hit_way_set[tlb_hit_way])
569 comb += rel_match.eq(rel_matches[tlb_hit_way])
570 with m.Else():
571 s_tag = Signal(TAG_BITS)
572 comb += s_tag.eq(get_tag(req_addr))
573 for i in range(NUM_WAYS): # way_t
574 is_tag_hit = Signal(name="is_tag_hit_%d" % i)
575 comb += is_tag_hit.eq(go & cache_i_validdx[i] &
576 (read_tag(i, cache_tag_set) == s_tag))
577 with m.If(is_tag_hit):
578 comb += hit_way.eq(i)
579 comb += is_hit.eq(1)
580 with m.If(s_tag == reload_tag):
581 comb += rel_match.eq(1)
582
583 return m
584
585
586 class DCache(Elaboratable):
587 """Set associative dcache write-through
588
589 TODO (in no specific order):
590 * See list in icache.vhdl
591 * Complete load misses on the cycle when WB data comes instead of
592 at the end of line (this requires dealing with requests coming in
593 while not idle...)
594 """
595 def __init__(self):
596 self.d_in = LoadStore1ToDCacheType("d_in")
597 self.d_out = DCacheToLoadStore1Type("d_out")
598
599 self.m_in = MMUToDCacheType("m_in")
600 self.m_out = DCacheToMMUType("m_out")
601
602 self.stall_out = Signal()
603
604 self.wb_out = WBMasterOut("wb_out")
605 self.wb_in = WBSlaveOut("wb_in")
606
607 self.log_out = Signal(20)
608
609 def stage_0(self, m, r0, r1, r0_full):
610 """Latch the request in r0.req as long as we're not stalling
611 """
612 comb = m.d.comb
613 sync = m.d.sync
614 d_in, d_out, m_in = self.d_in, self.d_out, self.m_in
615
616 r = RegStage0("stage0")
617
618 # TODO, this goes in unit tests and formal proofs
619 with m.If(d_in.valid & m_in.valid):
620 sync += Display("request collision loadstore vs MMU")
621
622 with m.If(m_in.valid):
623 comb += r.req.valid.eq(1)
624 comb += r.req.load.eq(~(m_in.tlbie | m_in.tlbld))# no invalidate
625 comb += r.req.dcbz.eq(0)
626 comb += r.req.nc.eq(0)
627 comb += r.req.reserve.eq(0)
628 comb += r.req.virt_mode.eq(0)
629 comb += r.req.priv_mode.eq(1)
630 comb += r.req.addr.eq(m_in.addr)
631 comb += r.req.data.eq(m_in.pte)
632 comb += r.req.byte_sel.eq(~0) # Const -1 sets all to 0b111....
633 comb += r.tlbie.eq(m_in.tlbie)
634 comb += r.doall.eq(m_in.doall)
635 comb += r.tlbld.eq(m_in.tlbld)
636 comb += r.mmu_req.eq(1)
637 m.d.sync += Display(" DCACHE req mmu addr %x pte %x ld %d",
638 m_in.addr, m_in.pte, r.req.load)
639
640 with m.Else():
641 comb += r.req.eq(d_in)
642 comb += r.req.data.eq(0)
643 comb += r.tlbie.eq(0)
644 comb += r.doall.eq(0)
645 comb += r.tlbld.eq(0)
646 comb += r.mmu_req.eq(0)
647 with m.If((~r1.full & ~d_in.hold) | ~r0_full):
648 sync += r0.eq(r)
649 sync += r0_full.eq(r.req.valid)
650 # Sample data the cycle after a request comes in from loadstore1.
651 # If another request has come in already then the data will get
652 # put directly into req.data below.
653 with m.If(r0.req.valid & ~r.req.valid & ~r0.d_valid &
654 ~r0.mmu_req):
655 sync += r0.req.data.eq(d_in.data)
656 sync += r0.d_valid.eq(1)
657 with m.If(d_in.valid):
658 m.d.sync += Display(" DCACHE req cache "
659 "virt %d addr %x data %x ld %d",
660 r.req.virt_mode, r.req.addr,
661 r.req.data, r.req.load)
662
663 def tlb_read(self, m, r0_stall, tlb_valid_way,
664 tlb_tag_way, tlb_pte_way, dtlb_valid_bits,
665 dtlb_tags, dtlb_ptes):
666 """TLB
667 Operates in the second cycle on the request latched in r0.req.
668 TLB updates write the entry at the end of the second cycle.
669 """
670 comb = m.d.comb
671 sync = m.d.sync
672 m_in, d_in = self.m_in, self.d_in
673
674 index = Signal(TLB_SET_BITS)
675 addrbits = Signal(TLB_SET_BITS)
676
677 amin = TLB_LG_PGSZ
678 amax = TLB_LG_PGSZ + TLB_SET_BITS
679
680 with m.If(m_in.valid):
681 comb += addrbits.eq(m_in.addr[amin : amax])
682 with m.Else():
683 comb += addrbits.eq(d_in.addr[amin : amax])
684 comb += index.eq(addrbits)
685
686 # If we have any op and the previous op isn't finished,
687 # then keep the same output for next cycle.
688 with m.If(~r0_stall):
689 sync += tlb_valid_way.eq(dtlb_valid_bits[index])
690 sync += tlb_tag_way.eq(dtlb_tags[index])
691 sync += tlb_pte_way.eq(dtlb_ptes[index])
692
693 def maybe_tlb_plrus(self, m, r1, tlb_plru_victim):
694 """Generate TLB PLRUs
695 """
696 comb = m.d.comb
697 sync = m.d.sync
698
699 if TLB_NUM_WAYS == 0:
700 return
701 for i in range(TLB_SET_SIZE):
702 # TLB PLRU interface
703 tlb_plru = PLRU(TLB_WAY_BITS)
704 setattr(m.submodules, "maybe_plru_%d" % i, tlb_plru)
705 tlb_plru_acc_en = Signal()
706
707 comb += tlb_plru_acc_en.eq(r1.tlb_hit & (r1.tlb_hit_index == i))
708 comb += tlb_plru.acc_en.eq(tlb_plru_acc_en)
709 comb += tlb_plru.acc_i.eq(r1.tlb_hit_way)
710 comb += tlb_plru_victim[i].eq(tlb_plru.lru_o)
711
712 def tlb_search(self, m, tlb_req_index, r0, r0_valid,
713 tlb_valid_way, tlb_tag_way, tlb_hit_way,
714 tlb_pte_way, pte, tlb_hit, valid_ra, perm_attr, ra):
715
716 comb = m.d.comb
717
718 hitway = Signal(TLB_WAY_BITS)
719 hit = Signal()
720 eatag = Signal(TLB_EA_TAG_BITS)
721
722 TLB_LG_END = TLB_LG_PGSZ + TLB_SET_BITS
723 comb += tlb_req_index.eq(r0.req.addr[TLB_LG_PGSZ : TLB_LG_END])
724 comb += eatag.eq(r0.req.addr[TLB_LG_END : 64 ])
725
726 for i in range(TLB_NUM_WAYS):
727 is_tag_hit = Signal(name="is_tag_hit%d" % i)
728 tlb_tag = Signal(TLB_EA_TAG_BITS, name="tlb_tag%d" % i)
729 comb += tlb_tag.eq(read_tlb_tag(i, tlb_tag_way))
730 comb += is_tag_hit.eq(tlb_valid_way[i] & (tlb_tag == eatag))
731 with m.If(is_tag_hit):
732 comb += hitway.eq(i)
733 comb += hit.eq(1)
734
735 comb += tlb_hit.eq(hit & r0_valid)
736 comb += tlb_hit_way.eq(hitway)
737
738 with m.If(tlb_hit):
739 comb += pte.eq(read_tlb_pte(hitway, tlb_pte_way))
740 comb += valid_ra.eq(tlb_hit | ~r0.req.virt_mode)
741
742 with m.If(r0.req.virt_mode):
743 comb += ra.eq(Cat(Const(0, ROW_OFF_BITS),
744 r0.req.addr[ROW_OFF_BITS:TLB_LG_PGSZ],
745 pte[TLB_LG_PGSZ:REAL_ADDR_BITS]))
746 comb += perm_attr.reference.eq(pte[8])
747 comb += perm_attr.changed.eq(pte[7])
748 comb += perm_attr.nocache.eq(pte[5])
749 comb += perm_attr.priv.eq(pte[3])
750 comb += perm_attr.rd_perm.eq(pte[2])
751 comb += perm_attr.wr_perm.eq(pte[1])
752 with m.Else():
753 comb += ra.eq(Cat(Const(0, ROW_OFF_BITS),
754 r0.req.addr[ROW_OFF_BITS:REAL_ADDR_BITS]))
755 comb += perm_attr.reference.eq(1)
756 comb += perm_attr.changed.eq(1)
757 comb += perm_attr.nocache.eq(0)
758 comb += perm_attr.priv.eq(1)
759 comb += perm_attr.rd_perm.eq(1)
760 comb += perm_attr.wr_perm.eq(1)
761
762 with m.If(valid_ra):
763 m.d.sync += Display("DCACHE virt mode %d hit %d ra %x pte %x",
764 r0.req.virt_mode, tlb_hit, ra, pte)
765 m.d.sync += Display(" perm ref=%d", perm_attr.reference)
766 m.d.sync += Display(" perm chg=%d", perm_attr.changed)
767 m.d.sync += Display(" perm noc=%d", perm_attr.nocache)
768 m.d.sync += Display(" perm prv=%d", perm_attr.priv)
769 m.d.sync += Display(" perm rdp=%d", perm_attr.rd_perm)
770 m.d.sync += Display(" perm wrp=%d", perm_attr.wr_perm)
771
772 def tlb_update(self, m, r0_valid, r0, dtlb_valid_bits, tlb_req_index,
773 tlb_hit_way, tlb_hit, tlb_plru_victim, tlb_tag_way,
774 dtlb_tags, tlb_pte_way, dtlb_ptes):
775
776 dtlb_valids = TLBValidBitsArray()
777
778 comb = m.d.comb
779 sync = m.d.sync
780
781 tlbie = Signal()
782 tlbwe = Signal()
783
784 comb += tlbie.eq(r0_valid & r0.tlbie)
785 comb += tlbwe.eq(r0_valid & r0.tlbld)
786
787 m.submodules.tlb_update = d = DTLBUpdate()
788 with m.If(tlbie & r0.doall):
789 # clear all valid bits at once
790 for i in range(TLB_SET_SIZE):
791 sync += dtlb_valid_bits[i].eq(0)
792 with m.If(d.updated):
793 sync += dtlb_tags[tlb_req_index].eq(d.tb_out)
794 sync += dtlb_ptes[tlb_req_index].eq(d.pb_out)
795 with m.If(d.v_updated):
796 sync += dtlb_valid_bits[tlb_req_index].eq(d.db_out)
797
798 comb += d.dv.eq(dtlb_valid_bits[tlb_req_index])
799
800 comb += d.tlbie.eq(tlbie)
801 comb += d.tlbwe.eq(tlbwe)
802 comb += d.doall.eq(r0.doall)
803 comb += d.tlb_hit.eq(tlb_hit)
804 comb += d.tlb_hit_way.eq(tlb_hit_way)
805 comb += d.tlb_tag_way.eq(tlb_tag_way)
806 comb += d.tlb_pte_way.eq(tlb_pte_way)
807 comb += d.tlb_req_index.eq(tlb_req_index)
808
809 with m.If(tlb_hit):
810 comb += d.repl_way.eq(tlb_hit_way)
811 with m.Else():
812 comb += d.repl_way.eq(tlb_plru_victim[tlb_req_index])
813 comb += d.eatag.eq(r0.req.addr[TLB_LG_PGSZ + TLB_SET_BITS:64])
814 comb += d.pte_data.eq(r0.req.data)
815
816 def maybe_plrus(self, m, r1, plru_victim):
817 """Generate PLRUs
818 """
819 comb = m.d.comb
820 sync = m.d.sync
821
822 if TLB_NUM_WAYS == 0:
823 return
824
825 for i in range(NUM_LINES):
826 # PLRU interface
827 plru = PLRU(WAY_BITS)
828 setattr(m.submodules, "plru%d" % i, plru)
829 plru_acc_en = Signal()
830
831 comb += plru_acc_en.eq(r1.cache_hit & (r1.hit_index == i))
832 comb += plru.acc_en.eq(plru_acc_en)
833 comb += plru.acc_i.eq(r1.hit_way)
834 comb += plru_victim[i].eq(plru.lru_o)
835
836 def cache_tag_read(self, m, r0_stall, req_index, cache_tag_set, cache_tags):
837 """Cache tag RAM read port
838 """
839 comb = m.d.comb
840 sync = m.d.sync
841 m_in, d_in = self.m_in, self.d_in
842
843 index = Signal(INDEX_BITS)
844
845 with m.If(r0_stall):
846 comb += index.eq(req_index)
847 with m.Elif(m_in.valid):
848 comb += index.eq(get_index(m_in.addr))
849 with m.Else():
850 comb += index.eq(get_index(d_in.addr))
851 sync += cache_tag_set.eq(cache_tags[index])
852
853 def dcache_request(self, m, r0, ra, req_index, req_row, req_tag,
854 r0_valid, r1, cache_valids, replace_way,
855 use_forward1_next, use_forward2_next,
856 req_hit_way, plru_victim, rc_ok, perm_attr,
857 valid_ra, perm_ok, access_ok, req_op, req_go,
858 tlb_pte_way,
859 tlb_hit, tlb_hit_way, tlb_valid_way, cache_tag_set,
860 cancel_store, req_same_tag, r0_stall, early_req_row):
861 """Cache request parsing and hit detection
862 """
863
864 comb = m.d.comb
865 m_in, d_in = self.m_in, self.d_in
866
867 is_hit = Signal()
868 hit_way = Signal(WAY_BITS)
869 op = Signal(Op)
870 opsel = Signal(3)
871 go = Signal()
872 nc = Signal()
873 hit_set = Array(Signal(name="hit_set_%d" % i) \
874 for i in range(TLB_NUM_WAYS))
875 cache_i_validdx = Signal(NUM_WAYS)
876
877 # Extract line, row and tag from request
878 comb += req_index.eq(get_index(r0.req.addr))
879 comb += req_row.eq(get_row(r0.req.addr))
880 comb += req_tag.eq(get_tag(ra))
881
882 if False: # display on comb is a bit... busy.
883 comb += Display("dcache_req addr:%x ra: %x idx: %x tag: %x row: %x",
884 r0.req.addr, ra, req_index, req_tag, req_row)
885
886 comb += go.eq(r0_valid & ~(r0.tlbie | r0.tlbld) & ~r1.ls_error)
887 comb += cache_i_validdx.eq(cache_valids[req_index])
888
889 m.submodules.dcache_pend = dc = DCachePendingHit(tlb_pte_way,
890 tlb_valid_way, tlb_hit_way,
891 cache_i_validdx, cache_tag_set,
892 r0.req.addr,
893 hit_set)
894
895 comb += dc.tlb_hit.eq(tlb_hit)
896 comb += dc.reload_tag.eq(r1.reload_tag)
897 comb += dc.virt_mode.eq(r0.req.virt_mode)
898 comb += dc.go.eq(go)
899 comb += dc.req_index.eq(req_index)
900 comb += is_hit.eq(dc.is_hit)
901 comb += hit_way.eq(dc.hit_way)
902 comb += req_same_tag.eq(dc.rel_match)
903
904 # See if the request matches the line currently being reloaded
905 with m.If((r1.state == State.RELOAD_WAIT_ACK) &
906 (req_index == r1.store_index) & req_same_tag):
907 # For a store, consider this a hit even if the row isn't
908 # valid since it will be by the time we perform the store.
909 # For a load, check the appropriate row valid bit.
910 rrow = Signal(ROW_LINE_BITS)
911 comb += rrow.eq(req_row)
912 valid = r1.rows_valid[rrow]
913 comb += is_hit.eq((~r0.req.load) | valid)
914 comb += hit_way.eq(replace_way)
915
916 # Whether to use forwarded data for a load or not
917 with m.If((get_row(r1.req.real_addr) == req_row) &
918 (r1.req.hit_way == hit_way)):
919 # Only need to consider r1.write_bram here, since if we
920 # are writing refill data here, then we don't have a
921 # cache hit this cycle on the line being refilled.
922 # (There is the possibility that the load following the
923 # load miss that started the refill could be to the old
924 # contents of the victim line, since it is a couple of
925 # cycles after the refill starts before we see the updated
926 # cache tag. In that case we don't use the bypass.)
927 comb += use_forward1_next.eq(r1.write_bram)
928 with m.If((r1.forward_row1 == req_row) & (r1.forward_way1 == hit_way)):
929 comb += use_forward2_next.eq(r1.forward_valid1)
930
931 # The way that matched on a hit
932 comb += req_hit_way.eq(hit_way)
933
934 # The way to replace on a miss
935 with m.If(r1.write_tag):
936 comb += replace_way.eq(plru_victim[r1.store_index])
937 with m.Else():
938 comb += replace_way.eq(r1.store_way)
939
940 # work out whether we have permission for this access
941 # NB we don't yet implement AMR, thus no KUAP
942 comb += rc_ok.eq(perm_attr.reference
943 & (r0.req.load | perm_attr.changed))
944 comb += perm_ok.eq((r0.req.priv_mode | (~perm_attr.priv)) &
945 (perm_attr.wr_perm |
946 (r0.req.load & perm_attr.rd_perm)))
947 comb += access_ok.eq(valid_ra & perm_ok & rc_ok)
948 # Combine the request and cache hit status to decide what
949 # operation needs to be done
950 comb += nc.eq(r0.req.nc | perm_attr.nocache)
951 comb += op.eq(Op.OP_NONE)
952 with m.If(go):
953 with m.If(~access_ok):
954 m.d.sync += Display("DCACHE access fail valid_ra=%d p=%d rc=%d",
955 valid_ra, perm_ok, rc_ok)
956 comb += op.eq(Op.OP_BAD)
957 with m.Elif(cancel_store):
958 m.d.sync += Display("DCACHE cancel store")
959 comb += op.eq(Op.OP_STCX_FAIL)
960 with m.Else():
961 m.d.sync += Display("DCACHE valid_ra=%d nc=%d ld=%d",
962 valid_ra, nc, r0.req.load)
963 comb += opsel.eq(Cat(is_hit, nc, r0.req.load))
964 with m.Switch(opsel):
965 with m.Case(0b101): comb += op.eq(Op.OP_LOAD_HIT)
966 with m.Case(0b100): comb += op.eq(Op.OP_LOAD_MISS)
967 with m.Case(0b110): comb += op.eq(Op.OP_LOAD_NC)
968 with m.Case(0b001): comb += op.eq(Op.OP_STORE_HIT)
969 with m.Case(0b000): comb += op.eq(Op.OP_STORE_MISS)
970 with m.Case(0b010): comb += op.eq(Op.OP_STORE_MISS)
971 with m.Case(0b011): comb += op.eq(Op.OP_BAD)
972 with m.Case(0b111): comb += op.eq(Op.OP_BAD)
973 comb += req_op.eq(op)
974 comb += req_go.eq(go)
975
976 # Version of the row number that is valid one cycle earlier
977 # in the cases where we need to read the cache data BRAM.
978 # If we're stalling then we need to keep reading the last
979 # row requested.
980 with m.If(~r0_stall):
981 with m.If(m_in.valid):
982 comb += early_req_row.eq(get_row(m_in.addr))
983 with m.Else():
984 comb += early_req_row.eq(get_row(d_in.addr))
985 with m.Else():
986 comb += early_req_row.eq(req_row)
987
988 def reservation_comb(self, m, cancel_store, set_rsrv, clear_rsrv,
989 r0_valid, r0, reservation):
990 """Handle load-with-reservation and store-conditional instructions
991 """
992 comb = m.d.comb
993
994 with m.If(r0_valid & r0.req.reserve):
995 # XXX generate alignment interrupt if address
996 # is not aligned XXX or if r0.req.nc = '1'
997 with m.If(r0.req.load):
998 comb += set_rsrv.eq(r0.req.atomic_last) # load with reservation
999 with m.Else():
1000 comb += clear_rsrv.eq(r0.req.atomic_last) # store conditional
1001 with m.If((~reservation.valid) |
1002 (r0.req.addr[LINE_OFF_BITS:64] != reservation.addr)):
1003 comb += cancel_store.eq(1)
1004
1005 def reservation_reg(self, m, r0_valid, access_ok, set_rsrv, clear_rsrv,
1006 reservation, r0):
1007
1008 comb = m.d.comb
1009 sync = m.d.sync
1010
1011 with m.If(r0_valid & access_ok):
1012 with m.If(clear_rsrv):
1013 sync += reservation.valid.eq(0)
1014 with m.Elif(set_rsrv):
1015 sync += reservation.valid.eq(1)
1016 sync += reservation.addr.eq(r0.req.addr[LINE_OFF_BITS:64])
1017
1018 def writeback_control(self, m, r1, cache_out_row):
1019 """Return data for loads & completion control logic
1020 """
1021 comb = m.d.comb
1022 sync = m.d.sync
1023 d_out, m_out = self.d_out, self.m_out
1024
1025 data_out = Signal(64)
1026 data_fwd = Signal(64)
1027
1028 # Use the bypass if are reading the row that was
1029 # written 1 or 2 cycles ago, including for the
1030 # slow_valid = 1 case (i.e. completing a load
1031 # miss or a non-cacheable load).
1032 with m.If(r1.use_forward1):
1033 comb += data_fwd.eq(r1.forward_data1)
1034 with m.Else():
1035 comb += data_fwd.eq(r1.forward_data2)
1036
1037 comb += data_out.eq(cache_out_row)
1038
1039 for i in range(8):
1040 with m.If(r1.forward_sel[i]):
1041 dsel = data_fwd.word_select(i, 8)
1042 comb += data_out.word_select(i, 8).eq(dsel)
1043
1044 comb += d_out.valid.eq(r1.ls_valid)
1045 comb += d_out.data.eq(data_out)
1046 comb += d_out.store_done.eq(~r1.stcx_fail)
1047 comb += d_out.error.eq(r1.ls_error)
1048 comb += d_out.cache_paradox.eq(r1.cache_paradox)
1049
1050 # Outputs to MMU
1051 comb += m_out.done.eq(r1.mmu_done)
1052 comb += m_out.err.eq(r1.mmu_error)
1053 comb += m_out.data.eq(data_out)
1054
1055 # We have a valid load or store hit or we just completed
1056 # a slow op such as a load miss, a NC load or a store
1057 #
1058 # Note: the load hit is delayed by one cycle. However it
1059 # can still not collide with r.slow_valid (well unless I
1060 # miscalculated) because slow_valid can only be set on a
1061 # subsequent request and not on its first cycle (the state
1062 # machine must have advanced), which makes slow_valid
1063 # at least 2 cycles from the previous hit_load_valid.
1064
1065 # Sanity: Only one of these must be set in any given cycle
1066
1067 if False: # TODO: need Display to get this to work
1068 assert (r1.slow_valid & r1.stcx_fail) != 1, \
1069 "unexpected slow_valid collision with stcx_fail"
1070
1071 assert ((r1.slow_valid | r1.stcx_fail) | r1.hit_load_valid) != 1, \
1072 "unexpected hit_load_delayed collision with slow_valid"
1073
1074 with m.If(~r1.mmu_req):
1075 # Request came from loadstore1...
1076 # Load hit case is the standard path
1077 with m.If(r1.hit_load_valid):
1078 sync += Display("completing load hit data=%x", data_out)
1079
1080 # error cases complete without stalling
1081 with m.If(r1.ls_error):
1082 with m.If(r1.dcbz):
1083 sync += Display("completing dcbz with error")
1084 with m.Else():
1085 sync += Display("completing ld/st with error")
1086
1087 # Slow ops (load miss, NC, stores)
1088 with m.If(r1.slow_valid):
1089 sync += Display("completing store or load miss adr=%x data=%x",
1090 r1.req.real_addr, data_out)
1091
1092 with m.Else():
1093 # Request came from MMU
1094 with m.If(r1.hit_load_valid):
1095 sync += Display("completing load hit to MMU, data=%x",
1096 m_out.data)
1097 # error cases complete without stalling
1098 with m.If(r1.mmu_error):
1099 sync += Display("combpleting MMU ld with error")
1100
1101 # Slow ops (i.e. load miss)
1102 with m.If(r1.slow_valid):
1103 sync += Display("completing MMU load miss, adr=%x data=%x",
1104 r1.req.real_addr, m_out.data)
1105
1106 def rams(self, m, r1, early_req_row, cache_out_row, replace_way):
1107 """rams
1108 Generate a cache RAM for each way. This handles the normal
1109 reads, writes from reloads and the special store-hit update
1110 path as well.
1111
1112 Note: the BRAMs have an extra read buffer, meaning the output
1113 is pipelined an extra cycle. This differs from the
1114 icache. The writeback logic needs to take that into
1115 account by using 1-cycle delayed signals for load hits.
1116 """
1117 comb = m.d.comb
1118 wb_in = self.wb_in
1119
1120 for i in range(NUM_WAYS):
1121 do_read = Signal(name="do_rd%d" % i)
1122 rd_addr = Signal(ROW_BITS, name="rd_addr_%d" % i)
1123 do_write = Signal(name="do_wr%d" % i)
1124 wr_addr = Signal(ROW_BITS, name="wr_addr_%d" % i)
1125 wr_data = Signal(WB_DATA_BITS, name="din_%d" % i)
1126 wr_sel = Signal(ROW_SIZE)
1127 wr_sel_m = Signal(ROW_SIZE)
1128 _d_out = Signal(WB_DATA_BITS, name="dout_%d" % i) # cache_row_t
1129
1130 way = CacheRam(ROW_BITS, WB_DATA_BITS, ADD_BUF=True, ram_num=i)
1131 setattr(m.submodules, "cacheram_%d" % i, way)
1132
1133 comb += way.rd_en.eq(do_read)
1134 comb += way.rd_addr.eq(rd_addr)
1135 comb += _d_out.eq(way.rd_data_o)
1136 comb += way.wr_sel.eq(wr_sel_m)
1137 comb += way.wr_addr.eq(wr_addr)
1138 comb += way.wr_data.eq(wr_data)
1139
1140 # Cache hit reads
1141 comb += do_read.eq(1)
1142 comb += rd_addr.eq(early_req_row)
1143 with m.If(r1.hit_way == i):
1144 comb += cache_out_row.eq(_d_out)
1145
1146 # Write mux:
1147 #
1148 # Defaults to wishbone read responses (cache refill)
1149 #
1150 # For timing, the mux on wr_data/sel/addr is not
1151 # dependent on anything other than the current state.
1152
1153 with m.If(r1.write_bram):
1154 # Write store data to BRAM. This happens one
1155 # cycle after the store is in r0.
1156 comb += wr_data.eq(r1.req.data)
1157 comb += wr_sel.eq(r1.req.byte_sel)
1158 comb += wr_addr.eq(get_row(r1.req.real_addr))
1159
1160 with m.If(i == r1.req.hit_way):
1161 comb += do_write.eq(1)
1162 with m.Else():
1163 # Otherwise, we might be doing a reload or a DCBZ
1164 with m.If(r1.dcbz):
1165 comb += wr_data.eq(0)
1166 with m.Else():
1167 comb += wr_data.eq(wb_in.dat)
1168 comb += wr_addr.eq(r1.store_row)
1169 comb += wr_sel.eq(~0) # all 1s
1170
1171 with m.If((r1.state == State.RELOAD_WAIT_ACK)
1172 & wb_in.ack & (replace_way == i)):
1173 comb += do_write.eq(1)
1174
1175 # Mask write selects with do_write since BRAM
1176 # doesn't have a global write-enable
1177 with m.If(do_write):
1178 comb += wr_sel_m.eq(wr_sel)
1179
1180 # Cache hit synchronous machine for the easy case.
1181 # This handles load hits.
1182 # It also handles error cases (TLB miss, cache paradox)
1183 def dcache_fast_hit(self, m, req_op, r0_valid, r0, r1,
1184 req_hit_way, req_index, req_tag, access_ok,
1185 tlb_hit, tlb_hit_way, tlb_req_index):
1186
1187 comb = m.d.comb
1188 sync = m.d.sync
1189
1190 with m.If(req_op != Op.OP_NONE):
1191 sync += Display("op:%d addr:%x nc: %d idx: %x tag: %x way: %x",
1192 req_op, r0.req.addr, r0.req.nc,
1193 req_index, req_tag, req_hit_way)
1194
1195 with m.If(r0_valid):
1196 sync += r1.mmu_req.eq(r0.mmu_req)
1197
1198 # Fast path for load/store hits.
1199 # Set signals for the writeback controls.
1200 sync += r1.hit_way.eq(req_hit_way)
1201 sync += r1.hit_index.eq(req_index)
1202
1203 with m.If(req_op == Op.OP_LOAD_HIT):
1204 sync += r1.hit_load_valid.eq(1)
1205 with m.Else():
1206 sync += r1.hit_load_valid.eq(0)
1207
1208 with m.If((req_op == Op.OP_LOAD_HIT) | (req_op == Op.OP_STORE_HIT)):
1209 sync += r1.cache_hit.eq(1)
1210 with m.Else():
1211 sync += r1.cache_hit.eq(0)
1212
1213 with m.If(req_op == Op.OP_BAD):
1214 sync += Display("Signalling ld/st error "
1215 "ls_error=%i mmu_error=%i cache_paradox=%i",
1216 ~r0.mmu_req,r0.mmu_req,access_ok)
1217 sync += r1.ls_error.eq(~r0.mmu_req)
1218 sync += r1.mmu_error.eq(r0.mmu_req)
1219 sync += r1.cache_paradox.eq(access_ok)
1220
1221 with m.Else():
1222 sync += r1.ls_error.eq(0)
1223 sync += r1.mmu_error.eq(0)
1224 sync += r1.cache_paradox.eq(0)
1225
1226 with m.If(req_op == Op.OP_STCX_FAIL):
1227 sync += r1.stcx_fail.eq(1)
1228 with m.Else():
1229 sync += r1.stcx_fail.eq(0)
1230
1231 # Record TLB hit information for updating TLB PLRU
1232 sync += r1.tlb_hit.eq(tlb_hit)
1233 sync += r1.tlb_hit_way.eq(tlb_hit_way)
1234 sync += r1.tlb_hit_index.eq(tlb_req_index)
1235
1236 # Memory accesses are handled by this state machine:
1237 #
1238 # * Cache load miss/reload (in conjunction with "rams")
1239 # * Load hits for non-cachable forms
1240 # * Stores (the collision case is handled in "rams")
1241 #
1242 # All wishbone requests generation is done here.
1243 # This machine operates at stage 1.
1244 def dcache_slow(self, m, r1, use_forward1_next, use_forward2_next,
1245 cache_valids, r0, replace_way,
1246 req_hit_way, req_same_tag,
1247 r0_valid, req_op, cache_tags, req_go, ra):
1248
1249 comb = m.d.comb
1250 sync = m.d.sync
1251 wb_in = self.wb_in
1252 d_in = self.d_in
1253
1254 req = MemAccessRequest("mreq_ds")
1255
1256 req_row = Signal(ROW_BITS)
1257 req_idx = Signal(INDEX_BITS)
1258 req_tag = Signal(TAG_BITS)
1259 comb += req_idx.eq(get_index(req.real_addr))
1260 comb += req_row.eq(get_row(req.real_addr))
1261 comb += req_tag.eq(get_tag(req.real_addr))
1262
1263 sync += r1.use_forward1.eq(use_forward1_next)
1264 sync += r1.forward_sel.eq(0)
1265
1266 with m.If(use_forward1_next):
1267 sync += r1.forward_sel.eq(r1.req.byte_sel)
1268 with m.Elif(use_forward2_next):
1269 sync += r1.forward_sel.eq(r1.forward_sel1)
1270
1271 sync += r1.forward_data2.eq(r1.forward_data1)
1272 with m.If(r1.write_bram):
1273 sync += r1.forward_data1.eq(r1.req.data)
1274 sync += r1.forward_sel1.eq(r1.req.byte_sel)
1275 sync += r1.forward_way1.eq(r1.req.hit_way)
1276 sync += r1.forward_row1.eq(get_row(r1.req.real_addr))
1277 sync += r1.forward_valid1.eq(1)
1278 with m.Else():
1279 with m.If(r1.dcbz):
1280 sync += r1.forward_data1.eq(0)
1281 with m.Else():
1282 sync += r1.forward_data1.eq(wb_in.dat)
1283 sync += r1.forward_sel1.eq(~0) # all 1s
1284 sync += r1.forward_way1.eq(replace_way)
1285 sync += r1.forward_row1.eq(r1.store_row)
1286 sync += r1.forward_valid1.eq(0)
1287
1288 # One cycle pulses reset
1289 sync += r1.slow_valid.eq(0)
1290 sync += r1.write_bram.eq(0)
1291 sync += r1.inc_acks.eq(0)
1292 sync += r1.dec_acks.eq(0)
1293
1294 sync += r1.ls_valid.eq(0)
1295 # complete tlbies and TLB loads in the third cycle
1296 sync += r1.mmu_done.eq(r0_valid & (r0.tlbie | r0.tlbld))
1297
1298 with m.If((req_op == Op.OP_LOAD_HIT) | (req_op == Op.OP_STCX_FAIL)):
1299 with m.If(~r0.mmu_req):
1300 sync += r1.ls_valid.eq(1)
1301 with m.Else():
1302 sync += r1.mmu_done.eq(1)
1303
1304 with m.If(r1.write_tag):
1305 # Store new tag in selected way
1306 for i in range(NUM_WAYS):
1307 with m.If(i == replace_way):
1308 ct = Signal(TAG_RAM_WIDTH)
1309 comb += ct.eq(cache_tags[r1.store_index])
1310 """
1311 TODO: check this
1312 cache_tags(r1.store_index)((i + 1) * TAG_WIDTH - 1 downto i * TAG_WIDTH) <=
1313 (TAG_WIDTH - 1 downto TAG_BITS => '0') & r1.reload_tag;
1314 """
1315 comb += ct.word_select(i, TAG_WIDTH).eq(r1.reload_tag)
1316 sync += cache_tags[r1.store_index].eq(ct)
1317 sync += r1.store_way.eq(replace_way)
1318 sync += r1.write_tag.eq(0)
1319
1320 # Take request from r1.req if there is one there,
1321 # else from req_op, ra, etc.
1322 with m.If(r1.full):
1323 comb += req.eq(r1.req)
1324 with m.Else():
1325 comb += req.op.eq(req_op)
1326 comb += req.valid.eq(req_go)
1327 comb += req.mmu_req.eq(r0.mmu_req)
1328 comb += req.dcbz.eq(r0.req.dcbz)
1329 comb += req.real_addr.eq(ra)
1330
1331 with m.If(r0.req.dcbz):
1332 # force data to 0 for dcbz
1333 comb += req.data.eq(0)
1334 with m.Elif(r0.d_valid):
1335 comb += req.data.eq(r0.req.data)
1336 with m.Else():
1337 comb += req.data.eq(d_in.data)
1338
1339 # Select all bytes for dcbz
1340 # and for cacheable loads
1341 with m.If(r0.req.dcbz | (r0.req.load & ~r0.req.nc)):
1342 comb += req.byte_sel.eq(~0) # all 1s
1343 with m.Else():
1344 comb += req.byte_sel.eq(r0.req.byte_sel)
1345 comb += req.hit_way.eq(req_hit_way)
1346 comb += req.same_tag.eq(req_same_tag)
1347
1348 # Store the incoming request from r0,
1349 # if it is a slow request
1350 # Note that r1.full = 1 implies req_op = OP_NONE
1351 with m.If((req_op == Op.OP_LOAD_MISS)
1352 | (req_op == Op.OP_LOAD_NC)
1353 | (req_op == Op.OP_STORE_MISS)
1354 | (req_op == Op.OP_STORE_HIT)):
1355 sync += r1.req.eq(req)
1356 sync += r1.full.eq(1)
1357
1358 # Main state machine
1359 with m.Switch(r1.state):
1360
1361 with m.Case(State.IDLE):
1362 sync += r1.wb.adr.eq(req.real_addr[ROW_LINE_BITS:])
1363 sync += r1.wb.sel.eq(req.byte_sel)
1364 sync += r1.wb.dat.eq(req.data)
1365 sync += r1.dcbz.eq(req.dcbz)
1366
1367 # Keep track of our index and way
1368 # for subsequent stores.
1369 sync += r1.store_index.eq(req_idx)
1370 sync += r1.store_row.eq(req_row)
1371 sync += r1.end_row_ix.eq(get_row_of_line(req_row)-1)
1372 sync += r1.reload_tag.eq(req_tag)
1373 sync += r1.req.same_tag.eq(1)
1374
1375 with m.If(req.op == Op.OP_STORE_HIT):
1376 sync += r1.store_way.eq(req.hit_way)
1377
1378 # Reset per-row valid bits,
1379 # ready for handling OP_LOAD_MISS
1380 for i in range(ROW_PER_LINE):
1381 sync += r1.rows_valid[i].eq(0)
1382
1383 with m.If(req_op != Op.OP_NONE):
1384 sync += Display("cache op %d", req.op)
1385
1386 with m.Switch(req.op):
1387 with m.Case(Op.OP_LOAD_HIT):
1388 # stay in IDLE state
1389 pass
1390
1391 with m.Case(Op.OP_LOAD_MISS):
1392 sync += Display("cache miss real addr: %x " \
1393 "idx: %x tag: %x",
1394 req.real_addr, req_row, req_tag)
1395
1396 # Start the wishbone cycle
1397 sync += r1.wb.we.eq(0)
1398 sync += r1.wb.cyc.eq(1)
1399 sync += r1.wb.stb.eq(1)
1400
1401 # Track that we had one request sent
1402 sync += r1.state.eq(State.RELOAD_WAIT_ACK)
1403 sync += r1.write_tag.eq(1)
1404
1405 with m.Case(Op.OP_LOAD_NC):
1406 sync += r1.wb.cyc.eq(1)
1407 sync += r1.wb.stb.eq(1)
1408 sync += r1.wb.we.eq(0)
1409 sync += r1.state.eq(State.NC_LOAD_WAIT_ACK)
1410
1411 with m.Case(Op.OP_STORE_HIT, Op.OP_STORE_MISS):
1412 with m.If(~req.dcbz):
1413 sync += r1.state.eq(State.STORE_WAIT_ACK)
1414 sync += r1.acks_pending.eq(1)
1415 sync += r1.full.eq(0)
1416 sync += r1.slow_valid.eq(1)
1417
1418 with m.If(~req.mmu_req):
1419 sync += r1.ls_valid.eq(1)
1420 with m.Else():
1421 sync += r1.mmu_done.eq(1)
1422
1423 with m.If(req.op == Op.OP_STORE_HIT):
1424 sync += r1.write_bram.eq(1)
1425 with m.Else():
1426 # dcbz is handled much like a load miss except
1427 # that we are writing to memory instead of reading
1428 sync += r1.state.eq(State.RELOAD_WAIT_ACK)
1429
1430 with m.If(req.op == Op.OP_STORE_MISS):
1431 sync += r1.write_tag.eq(1)
1432
1433 sync += r1.wb.we.eq(1)
1434 sync += r1.wb.cyc.eq(1)
1435 sync += r1.wb.stb.eq(1)
1436
1437 # OP_NONE and OP_BAD do nothing
1438 # OP_BAD & OP_STCX_FAIL were
1439 # handled above already
1440 with m.Case(Op.OP_NONE):
1441 pass
1442 with m.Case(Op.OP_BAD):
1443 pass
1444 with m.Case(Op.OP_STCX_FAIL):
1445 pass
1446
1447 with m.Case(State.RELOAD_WAIT_ACK):
1448 ld_stbs_done = Signal()
1449 # Requests are all sent if stb is 0
1450 comb += ld_stbs_done.eq(~r1.wb.stb)
1451
1452 # If we are still sending requests, was one accepted?
1453 with m.If((~wb_in.stall) & r1.wb.stb):
1454 # That was the last word? We are done sending.
1455 # Clear stb and set ld_stbs_done so we can handle an
1456 # eventual last ack on the same cycle.
1457 # sigh - reconstruct wb adr with 3 extra 0s at front
1458 wb_adr = Cat(Const(0, ROW_OFF_BITS), r1.wb.adr)
1459 with m.If(is_last_row_addr(wb_adr, r1.end_row_ix)):
1460 sync += r1.wb.stb.eq(0)
1461 comb += ld_stbs_done.eq(1)
1462
1463 # Calculate the next row address in the current cache line
1464 row = Signal(LINE_OFF_BITS-ROW_OFF_BITS)
1465 comb += row.eq(r1.wb.adr)
1466 sync += r1.wb.adr[:LINE_OFF_BITS-ROW_OFF_BITS].eq(row+1)
1467
1468 # Incoming acks processing
1469 sync += r1.forward_valid1.eq(wb_in.ack)
1470 with m.If(wb_in.ack):
1471 srow = Signal(ROW_LINE_BITS)
1472 comb += srow.eq(r1.store_row)
1473 sync += r1.rows_valid[srow].eq(1)
1474
1475 # If this is the data we were looking for,
1476 # we can complete the request next cycle.
1477 # Compare the whole address in case the
1478 # request in r1.req is not the one that
1479 # started this refill.
1480 with m.If(req.valid & r1.req.same_tag &
1481 ((r1.dcbz & r1.req.dcbz) |
1482 (~r1.dcbz & (r1.req.op == Op.OP_LOAD_MISS))) &
1483 (r1.store_row == get_row(req.real_addr))):
1484 sync += r1.full.eq(0)
1485 sync += r1.slow_valid.eq(1)
1486 with m.If(~r1.mmu_req):
1487 sync += r1.ls_valid.eq(1)
1488 with m.Else():
1489 sync += r1.mmu_done.eq(1)
1490 sync += r1.forward_sel.eq(~0) # all 1s
1491 sync += r1.use_forward1.eq(1)
1492
1493 # Check for completion
1494 with m.If(ld_stbs_done & is_last_row(r1.store_row,
1495 r1.end_row_ix)):
1496 # Complete wishbone cycle
1497 sync += r1.wb.cyc.eq(0)
1498
1499 # Cache line is now valid
1500 cv = Signal(INDEX_BITS)
1501 comb += cv.eq(cache_valids[r1.store_index])
1502 comb += cv.bit_select(r1.store_way, 1).eq(1)
1503 sync += cache_valids[r1.store_index].eq(cv)
1504
1505 sync += r1.state.eq(State.IDLE)
1506 sync += Display("cache valid set %x "
1507 "idx %d way %d",
1508 cv, r1.store_index, r1.store_way)
1509
1510 # Increment store row counter
1511 sync += r1.store_row.eq(next_row(r1.store_row))
1512
1513 with m.Case(State.STORE_WAIT_ACK):
1514 st_stbs_done = Signal()
1515 acks = Signal(3)
1516 adjust_acks = Signal(3)
1517
1518 comb += st_stbs_done.eq(~r1.wb.stb)
1519 comb += acks.eq(r1.acks_pending)
1520
1521 with m.If(r1.inc_acks != r1.dec_acks):
1522 with m.If(r1.inc_acks):
1523 comb += adjust_acks.eq(acks + 1)
1524 with m.Else():
1525 comb += adjust_acks.eq(acks - 1)
1526 with m.Else():
1527 comb += adjust_acks.eq(acks)
1528
1529 sync += r1.acks_pending.eq(adjust_acks)
1530
1531 # Clear stb when slave accepted request
1532 with m.If(~wb_in.stall):
1533 # See if there is another store waiting
1534 # to be done which is in the same real page.
1535 with m.If(req.valid):
1536 _ra = req.real_addr[ROW_LINE_BITS:SET_SIZE_BITS]
1537 sync += r1.wb.adr[0:SET_SIZE_BITS].eq(_ra)
1538 sync += r1.wb.dat.eq(req.data)
1539 sync += r1.wb.sel.eq(req.byte_sel)
1540
1541 with m.If((adjust_acks < 7) & req.same_tag &
1542 ((req.op == Op.OP_STORE_MISS)
1543 | (req.op == Op.OP_STORE_HIT))):
1544 sync += r1.wb.stb.eq(1)
1545 comb += st_stbs_done.eq(0)
1546
1547 with m.If(req.op == Op.OP_STORE_HIT):
1548 sync += r1.write_bram.eq(1)
1549 sync += r1.full.eq(0)
1550 sync += r1.slow_valid.eq(1)
1551
1552 # Store requests never come from the MMU
1553 sync += r1.ls_valid.eq(1)
1554 comb += st_stbs_done.eq(0)
1555 sync += r1.inc_acks.eq(1)
1556 with m.Else():
1557 sync += r1.wb.stb.eq(0)
1558 comb += st_stbs_done.eq(1)
1559
1560 # Got ack ? See if complete.
1561 with m.If(wb_in.ack):
1562 with m.If(st_stbs_done & (adjust_acks == 1)):
1563 sync += r1.state.eq(State.IDLE)
1564 sync += r1.wb.cyc.eq(0)
1565 sync += r1.wb.stb.eq(0)
1566 sync += r1.dec_acks.eq(1)
1567
1568 with m.Case(State.NC_LOAD_WAIT_ACK):
1569 # Clear stb when slave accepted request
1570 with m.If(~wb_in.stall):
1571 sync += r1.wb.stb.eq(0)
1572
1573 # Got ack ? complete.
1574 with m.If(wb_in.ack):
1575 sync += r1.state.eq(State.IDLE)
1576 sync += r1.full.eq(0)
1577 sync += r1.slow_valid.eq(1)
1578
1579 with m.If(~r1.mmu_req):
1580 sync += r1.ls_valid.eq(1)
1581 with m.Else():
1582 sync += r1.mmu_done.eq(1)
1583
1584 sync += r1.forward_sel.eq(~0) # all 1s
1585 sync += r1.use_forward1.eq(1)
1586 sync += r1.wb.cyc.eq(0)
1587 sync += r1.wb.stb.eq(0)
1588
1589 def dcache_log(self, m, r1, valid_ra, tlb_hit_way, stall_out):
1590
1591 sync = m.d.sync
1592 d_out, wb_in, log_out = self.d_out, self.wb_in, self.log_out
1593
1594 sync += log_out.eq(Cat(r1.state[:3], valid_ra, tlb_hit_way[:3],
1595 stall_out, req_op[:3], d_out.valid, d_out.error,
1596 r1.wb.cyc, r1.wb.stb, wb_in.ack, wb_in.stall,
1597 r1.real_adr[3:6]))
1598
1599 def elaborate(self, platform):
1600
1601 m = Module()
1602 comb = m.d.comb
1603 d_in = self.d_in
1604
1605 # Storage. Hopefully "cache_rows" is a BRAM, the rest is LUTs
1606 cache_tags = CacheTagArray()
1607 cache_tag_set = Signal(TAG_RAM_WIDTH)
1608 cache_valids = CacheValidBitsArray()
1609
1610 # TODO attribute ram_style : string;
1611 # TODO attribute ram_style of cache_tags : signal is "distributed";
1612
1613 """note: these are passed to nmigen.hdl.Memory as "attributes".
1614 don't know how, just that they are.
1615 """
1616 dtlb_valid_bits = TLBValidBitsArray()
1617 dtlb_tags = TLBTagsArray()
1618 dtlb_ptes = TLBPtesArray()
1619 # TODO attribute ram_style of
1620 # dtlb_tags : signal is "distributed";
1621 # TODO attribute ram_style of
1622 # dtlb_ptes : signal is "distributed";
1623
1624 r0 = RegStage0("r0")
1625 r0_full = Signal()
1626
1627 r1 = RegStage1("r1")
1628
1629 reservation = Reservation()
1630
1631 # Async signals on incoming request
1632 req_index = Signal(INDEX_BITS)
1633 req_row = Signal(ROW_BITS)
1634 req_hit_way = Signal(WAY_BITS)
1635 req_tag = Signal(TAG_BITS)
1636 req_op = Signal(Op)
1637 req_data = Signal(64)
1638 req_same_tag = Signal()
1639 req_go = Signal()
1640
1641 early_req_row = Signal(ROW_BITS)
1642
1643 cancel_store = Signal()
1644 set_rsrv = Signal()
1645 clear_rsrv = Signal()
1646
1647 r0_valid = Signal()
1648 r0_stall = Signal()
1649
1650 use_forward1_next = Signal()
1651 use_forward2_next = Signal()
1652
1653 cache_out_row = Signal(WB_DATA_BITS)
1654
1655 plru_victim = PLRUOut()
1656 replace_way = Signal(WAY_BITS)
1657
1658 # Wishbone read/write/cache write formatting signals
1659 bus_sel = Signal(8)
1660
1661 # TLB signals
1662 tlb_tag_way = Signal(TLB_TAG_WAY_BITS)
1663 tlb_pte_way = Signal(TLB_PTE_WAY_BITS)
1664 tlb_valid_way = Signal(TLB_NUM_WAYS)
1665 tlb_req_index = Signal(TLB_SET_BITS)
1666 tlb_hit = Signal()
1667 tlb_hit_way = Signal(TLB_WAY_BITS)
1668 pte = Signal(TLB_PTE_BITS)
1669 ra = Signal(REAL_ADDR_BITS)
1670 valid_ra = Signal()
1671 perm_attr = PermAttr("dc_perms")
1672 rc_ok = Signal()
1673 perm_ok = Signal()
1674 access_ok = Signal()
1675
1676 tlb_plru_victim = TLBPLRUOut()
1677
1678 # we don't yet handle collisions between loadstore1 requests
1679 # and MMU requests
1680 comb += self.m_out.stall.eq(0)
1681
1682 # Hold off the request in r0 when r1 has an uncompleted request
1683 comb += r0_stall.eq(r0_full & (r1.full | d_in.hold))
1684 comb += r0_valid.eq(r0_full & ~r1.full & ~d_in.hold)
1685 comb += self.stall_out.eq(r0_stall)
1686
1687 # Wire up wishbone request latch out of stage 1
1688 comb += self.wb_out.eq(r1.wb)
1689
1690 # deal with litex not doing wishbone pipeline mode
1691 # XXX in wrong way. FIFOs are needed in the SRAM test
1692 # so that stb/ack match up
1693 comb += self.wb_in.stall.eq(self.wb_out.cyc & ~self.wb_in.ack)
1694
1695 # call sub-functions putting everything together, using shared
1696 # signals established above
1697 self.stage_0(m, r0, r1, r0_full)
1698 self.tlb_read(m, r0_stall, tlb_valid_way,
1699 tlb_tag_way, tlb_pte_way, dtlb_valid_bits,
1700 dtlb_tags, dtlb_ptes)
1701 self.tlb_search(m, tlb_req_index, r0, r0_valid,
1702 tlb_valid_way, tlb_tag_way, tlb_hit_way,
1703 tlb_pte_way, pte, tlb_hit, valid_ra, perm_attr, ra)
1704 self.tlb_update(m, r0_valid, r0, dtlb_valid_bits, tlb_req_index,
1705 tlb_hit_way, tlb_hit, tlb_plru_victim, tlb_tag_way,
1706 dtlb_tags, tlb_pte_way, dtlb_ptes)
1707 self.maybe_plrus(m, r1, plru_victim)
1708 self.maybe_tlb_plrus(m, r1, tlb_plru_victim)
1709 self.cache_tag_read(m, r0_stall, req_index, cache_tag_set, cache_tags)
1710 self.dcache_request(m, r0, ra, req_index, req_row, req_tag,
1711 r0_valid, r1, cache_valids, replace_way,
1712 use_forward1_next, use_forward2_next,
1713 req_hit_way, plru_victim, rc_ok, perm_attr,
1714 valid_ra, perm_ok, access_ok, req_op, req_go,
1715 tlb_pte_way,
1716 tlb_hit, tlb_hit_way, tlb_valid_way, cache_tag_set,
1717 cancel_store, req_same_tag, r0_stall, early_req_row)
1718 self.reservation_comb(m, cancel_store, set_rsrv, clear_rsrv,
1719 r0_valid, r0, reservation)
1720 self.reservation_reg(m, r0_valid, access_ok, set_rsrv, clear_rsrv,
1721 reservation, r0)
1722 self.writeback_control(m, r1, cache_out_row)
1723 self.rams(m, r1, early_req_row, cache_out_row, replace_way)
1724 self.dcache_fast_hit(m, req_op, r0_valid, r0, r1,
1725 req_hit_way, req_index, req_tag, access_ok,
1726 tlb_hit, tlb_hit_way, tlb_req_index)
1727 self.dcache_slow(m, r1, use_forward1_next, use_forward2_next,
1728 cache_valids, r0, replace_way,
1729 req_hit_way, req_same_tag,
1730 r0_valid, req_op, cache_tags, req_go, ra)
1731 #self.dcache_log(m, r1, valid_ra, tlb_hit_way, stall_out)
1732
1733 return m
1734
1735
1736 if __name__ == '__main__':
1737 dut = DCache()
1738 vl = rtlil.convert(dut, ports=[])
1739 with open("test_dcache.il", "w") as f:
1740 f.write(vl)