From 3b9f287bab287f34285d317dd1d23f41bda77655 Mon Sep 17 00:00:00 2001 From: Florent Kermarrec Date: Tue, 16 Jun 2015 19:06:24 +0200 Subject: [PATCH] sdram: use wishbone cache as L2 cache and add optional L2 cache to Minicon --- misoclib/mem/sdram/core/minicon/__init__.py | 4 +- misoclib/mem/sdram/frontend/wishbone2lasmi.py | 181 +++--------------- misoclib/soc/sdram.py | 31 ++- software/libbase/system.c | 4 +- 4 files changed, 59 insertions(+), 161 deletions(-) diff --git a/misoclib/mem/sdram/core/minicon/__init__.py b/misoclib/mem/sdram/core/minicon/__init__.py index 6789fd06..77259a71 100644 --- a/misoclib/mem/sdram/core/minicon/__init__.py +++ b/misoclib/mem/sdram/core/minicon/__init__.py @@ -58,8 +58,8 @@ class _Bank(Module): class MiniconSettings: - def __init__(self): - pass + def __init__(self, l2_size=0): + self.l2_size = l2_size class Minicon(Module): diff --git a/misoclib/mem/sdram/frontend/wishbone2lasmi.py b/misoclib/mem/sdram/frontend/wishbone2lasmi.py index d13999e8..88270889 100644 --- a/misoclib/mem/sdram/frontend/wishbone2lasmi.py +++ b/misoclib/mem/sdram/frontend/wishbone2lasmi.py @@ -1,168 +1,49 @@ from migen.fhdl.std import * -from migen.bus import wishbone -from migen.bank.description import * from migen.genlib.fsm import FSM, NextState -from migen.genlib.misc import split, displacer, chooser -from migen.genlib.record import Record, layout_len - -# cachesize (in 32-bit words) is the size of the data store, must be a power of 2 -class WB2LASMI(Module, AutoCSR): - def __init__(self, cachesize, lasmim): - self._cachesize = CSRStatus(8, reset=log2_int(cachesize)) - self.wishbone = wishbone.Interface() +class WB2LASMI(Module): + def __init__(self, wishbone, lasmim): ### - data_width = flen(self.wishbone.dat_r) - if lasmim.dw > data_width and (lasmim.dw % data_width) != 0: - raise ValueError("LASMI data width must be a multiple of {dw}".format(dw=data_width)) - if lasmim.dw < data_width and (data_width % lasmim.dw) != 0: - raise ValueError("WISHBONE data width must be a multiple of {dw}".format(dw=lasmim.dw)) - - # Split address: - # TAG | LINE NUMBER | LINE OFFSET - offsetbits = log2_int(max(lasmim.dw//data_width, 1)) - addressbits = lasmim.aw + offsetbits - linebits = log2_int(cachesize) - offsetbits - tagbits = addressbits - linebits - wordbits = log2_int(max(data_width//lasmim.dw, 1)) - adr_offset, adr_line, adr_tag = split(self.wishbone.adr, offsetbits, linebits, tagbits) - word = Signal(wordbits) if wordbits else None - - # Data memory - data_mem = Memory(lasmim.dw*2**wordbits, 2**linebits) - data_port = data_mem.get_port(write_capable=True, we_granularity=8) - self.specials += data_mem, data_port - - write_from_lasmi = Signal() - write_to_lasmi = Signal() - if adr_offset is None: - adr_offset_r = None - else: - adr_offset_r = Signal(offsetbits) - self.sync += adr_offset_r.eq(adr_offset) - - self.comb += [ - data_port.adr.eq(adr_line), - If(write_from_lasmi, - displacer(lasmim.dat_r, word, data_port.dat_w), - displacer(Replicate(1, lasmim.dw//8), word, data_port.we) - ).Else( - data_port.dat_w.eq(Replicate(self.wishbone.dat_w, max(lasmim.dw//data_width, 1))), - If(self.wishbone.cyc & self.wishbone.stb & self.wishbone.we & self.wishbone.ack, - displacer(self.wishbone.sel, adr_offset, data_port.we, 2**offsetbits, reverse=True) - ) - ), - If(write_to_lasmi, - chooser(data_port.dat_r, word, lasmim.dat_w), - lasmim.dat_we.eq(2**(lasmim.dw//8)-1) - ), - chooser(data_port.dat_r, adr_offset_r, self.wishbone.dat_r, reverse=True) - ] - - - # Tag memory - tag_layout = [("tag", tagbits), ("dirty", 1)] - tag_mem = Memory(layout_len(tag_layout), 2**linebits) - tag_port = tag_mem.get_port(write_capable=True) - self.specials += tag_mem, tag_port - tag_do = Record(tag_layout) - tag_di = Record(tag_layout) - self.comb += [ - tag_do.raw_bits().eq(tag_port.dat_r), - tag_port.dat_w.eq(tag_di.raw_bits()) - ] - - self.comb += [ - tag_port.adr.eq(adr_line), - tag_di.tag.eq(adr_tag) - ] - if word is not None: - self.comb += lasmim.adr.eq(Cat(word, adr_line, tag_do.tag)) - else: - self.comb += lasmim.adr.eq(Cat(adr_line, tag_do.tag)) - - # Lasmim word computation, word_clr and word_inc will be simplified - # at synthesis when wordbits=0 - word_clr = Signal() - word_inc = Signal() - if word is not None: - self.sync += \ - If(word_clr, - word.eq(0), - ).Elif(word_inc, - word.eq(word+1) - ) - - def word_is_last(word): - if word is not None: - return word == 2**wordbits-1 - else: - return 1 - # Control FSM - assert(lasmim.write_latency >= 1 and lasmim.read_latency >= 1) - fsm = FSM(reset_state="IDLE") - self.submodules += fsm - - + self.submodules.fsm = fsm = FSM(reset_state="IDLE") fsm.act("IDLE", - If(self.wishbone.cyc & self.wishbone.stb, NextState("TEST_HIT")) - ) - fsm.act("TEST_HIT", - word_clr.eq(1), - If(tag_do.tag == adr_tag, - self.wishbone.ack.eq(1), - If(self.wishbone.we, - tag_di.dirty.eq(1), - tag_port.we.eq(1) - ), - NextState("IDLE") - ).Else( - If(tag_do.dirty, - NextState("EVICT_REQUEST") - ).Else( - NextState("REFILL_WRTAG") - ) + If(wishbone.cyc & wishbone.stb, + NextState("REQUEST") ) ) - - fsm.act("EVICT_REQUEST", + fsm.act("REQUEST", lasmim.stb.eq(1), - lasmim.we.eq(1), - If(lasmim.req_ack, NextState("EVICT_DATA")) - ) - fsm.act("EVICT_DATA", - If(lasmim.dat_w_ack, - write_to_lasmi.eq(1), - word_inc.eq(1), - If(word_is_last(word), - NextState("REFILL_WRTAG"), + lasmim.we.eq(wishbone.we), + If(lasmim.req_ack, + If(wishbone.we, + NextState("WRITE_DATA") ).Else( - NextState("EVICT_REQUEST") + NextState("READ_DATA") ) ) ) - - fsm.act("REFILL_WRTAG", - # Write the tag first to set the LASMI address - tag_port.we.eq(1), - word_clr.eq(1), - NextState("REFILL_REQUEST") - ) - fsm.act("REFILL_REQUEST", - lasmim.stb.eq(1), - If(lasmim.req_ack, NextState("REFILL_DATA")) + fsm.act("WRITE_DATA", + If(lasmim.dat_w_ack, + lasmim.dat_we.eq(wishbone.sel), + wishbone.ack.eq(1), + NextState("IDLE") + ) ) - fsm.act("REFILL_DATA", + fsm.act("READ_DATA", If(lasmim.dat_r_ack, - write_from_lasmi.eq(1), - word_inc.eq(1), - If(word_is_last(word), - NextState("TEST_HIT"), - ).Else( - NextState("REFILL_REQUEST") - ) - ) + wishbone.ack.eq(1), + NextState("IDLE") + ), + NextState("IDLE") ) + + # Address / Datapath + self.comb += [ + lasmim.adr.eq(wishbone.adr), + If(lasmim.dat_w_ack, + lasmim.dat_w.eq(wishbone.dat_w), + ), + wishbone.dat_r.eq(lasmim.dat_r) + ] diff --git a/misoclib/soc/sdram.py b/misoclib/soc/sdram.py index fae706c7..124b7144 100644 --- a/misoclib/soc/sdram.py +++ b/misoclib/soc/sdram.py @@ -12,7 +12,7 @@ from misoclib.soc import SoC class SDRAMSoC(SoC): csr_map = { "sdram": 8, - "wishbone2lasmi": 9, + "l2_cache": 9, "memtest_w": 10, "memtest_r": 11 } @@ -45,6 +45,7 @@ class SDRAMSoC(SoC): phy.module.geom_settings.colbits)*sdram_width//8 # XXX: Limit main_ram_size to 256MB, we should modify mem_map to allow larger memories. main_ram_size = min(main_ram_size, 256*1024*1024) + l2_size = self.sdram_controller_settings.l2_size # LASMICON frontend if isinstance(self.sdram_controller_settings, LASMIconSettings): @@ -55,23 +56,39 @@ class SDRAMSoC(SoC): self.submodules.memtest_w = memtest.MemtestWriter(self.sdram.crossbar.get_master()) self.submodules.memtest_r = memtest.MemtestReader(self.sdram.crossbar.get_master()) - l2_size = self.sdram_controller_settings.l2_size if l2_size: + sdram_bus = wishbone.Interface() + lasmim = self.sdram.crossbar.get_master() + l2_cache = wishbone.Cache(l2_size//4, sdram_bus, wishbone.Interface(lasmim.dw)) # XXX Vivado ->2015.1 workaround, Vivado is not able to map correctly our L2 cache. # Issue is reported to Xilinx and should be fixed in next releases (2015.2?). # Remove this workaround when fixed by Xilinx. from mibuild.xilinx.vivado import XilinxVivadoToolchain if isinstance(self.platform.toolchain, XilinxVivadoToolchain): from migen.fhdl.simplify import FullMemoryWE - self.submodules.wishbone2lasmi = FullMemoryWE()(wishbone2lasmi.WB2LASMI(l2_size//4, self.sdram.crossbar.get_master())) + self.submodules.l2_cache = FullMemoryWE()(l2_cache) else: - self.submodules.wishbone2lasmi = wishbone2lasmi.WB2LASMI(l2_size//4, self.sdram.crossbar.get_master()) - self.register_mem("main_ram", self.mem_map["main_ram"], self.wishbone2lasmi.wishbone, main_ram_size) + self.submodules.l2_cache = l2_cache + self.submodules.wishbone2lasmi = wishbone2lasmi.WB2LASMI(self.l2_cache.slave, lasmim) + self.register_mem("main_ram", self.mem_map["main_ram"], sdram_bus, main_ram_size) # MINICON frontend elif isinstance(self.sdram_controller_settings, MiniconSettings): - self.submodules.converter = wishbone.Converter(wishbone.Interface(), self.sdram.controller.bus) - self.register_mem("main_ram", self.mem_map["main_ram"], self.converter.master, main_ram_size) + sdram_bus = wishbone.Interface() + if l2_size: + l2_cache = wishbone.Cache(l2_size//4, sdram_bus, self.sdram.controller.bus) + # XXX Vivado ->2015.1 workaround, Vivado is not able to map correctly our L2 cache. + # Issue is reported to Xilinx and should be fixed in next releases (2015.2?). + # Remove this workaround when fixed by Xilinx. + from mibuild.xilinx.vivado import XilinxVivadoToolchain + if isinstance(self.platform.toolchain, XilinxVivadoToolchain): + from migen.fhdl.simplify import FullMemoryWE + self.submodules.l2_cache = FullMemoryWE()(l2_cache) + else: + self.submodules.l2_cache = l2_cache + else: + self.submodules.converter = wishbone.Converter(sdram_bus, self.sdram.controller.bus) + self.register_mem("main_ram", self.mem_map["main_ram"], sdram_bus, main_ram_size) def do_finalize(self): if not self.integrated_main_ram_size: diff --git a/software/libbase/system.c b/software/libbase/system.c index 607d122d..0bf30996 100644 --- a/software/libbase/system.c +++ b/software/libbase/system.c @@ -67,7 +67,7 @@ void flush_cpu_dcache(void) #endif } -#ifdef CSR_WISHBONE2LASMI_BASE +#ifdef CSR_L2_CACHE_BASE void flush_l2_cache(void) { unsigned int l2_nwords; @@ -75,7 +75,7 @@ void flush_l2_cache(void) register unsigned int addr; register unsigned int dummy; - l2_nwords = 1 << wishbone2lasmi_cachesize_read(); + l2_nwords = 1 << l2_cache_size_read(); for(i=0;i<2*l2_nwords;i++) { addr = MAIN_RAM_BASE + i*4; #if defined (__lm32__) -- 2.30.2