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rocket-chip/rocket/src/main/scala/htif.scala
2012-10-16 02:24:37 -07:00

245 lines
8.7 KiB
Scala

package rocket
import Chisel._
import Node._;
import Constants._;
import uncore._
class ioDebug extends Bundle
{
val error_mode = Bool(OUTPUT);
}
class ioHost(w: Int) extends Bundle
{
val in = new FIFOIO()(Bits(width = w)).flip
val out = new FIFOIO()(Bits(width = w))
}
class PCRReq extends Bundle
{
val rw = Bool()
val addr = Bits(width = 6)
val data = Bits(width = 64)
}
class ioHTIF extends Bundle
{
val reset = Bool(INPUT)
val debug = new ioDebug
val pcr_req = (new FIFOIO) { new PCRReq }.flip
val pcr_rep = (new FIFOIO) { Bits(width = 64) }
val ipi_req = (new FIFOIO) { Bits(width = log2Up(NTILES)) }
val ipi_rep = (new FIFOIO) { Bool() }.flip
}
class rocketHTIF(w: Int, ncores: Int, co: CoherencePolicyWithUncached) extends Component
{
val io = new Bundle {
val host = new ioHost(w)
val cpu = Vec(ncores) { new ioHTIF().flip }
val mem = new ioTileLink
}
val short_request_bits = 64
val long_request_bits = 576
require(short_request_bits % w == 0)
val rx_count_w = 13 + log2Up(64) - log2Up(w) // data size field is 12 bits
val rx_count = Reg(resetVal = UFix(0,rx_count_w))
val rx_shifter = Reg() { Bits(width = short_request_bits) }
val rx_shifter_in = Cat(io.host.in.bits, rx_shifter(short_request_bits-1,w))
val next_cmd = rx_shifter_in(3,0)
val cmd = Reg() { Bits() }
val size = Reg() { Bits() }
val pos = Reg() { Bits() }
val seqno = Reg() { Bits() }
val addr = Reg() { Bits() }
when (io.host.in.valid && io.host.in.ready) {
rx_shifter := rx_shifter_in
rx_count := rx_count + UFix(1)
when (rx_count === UFix(short_request_bits/w-1)) {
cmd := next_cmd
size := rx_shifter_in(15,4)
pos := rx_shifter_in(15,4+OFFSET_BITS-3)
seqno := rx_shifter_in(23,16)
addr := rx_shifter_in(63,24)
}
}
val rx_word_count = (rx_count >> UFix(log2Up(short_request_bits/w)))
val rx_word_done = io.host.in.valid && rx_count(log2Up(short_request_bits/w)-1,0).andR
val packet_ram_depth = long_request_bits/short_request_bits-1
val packet_ram = Vec(packet_ram_depth) { Reg() { Bits(width = short_request_bits) } }
when (rx_word_done && io.host.in.ready) {
packet_ram(rx_word_count(log2Up(packet_ram_depth)-1,0) - UFix(1)) := rx_shifter_in
}
val cmd_readmem :: cmd_writemem :: cmd_readcr :: cmd_writecr :: cmd_ack :: cmd_nack :: Nil = Enum(6) { UFix() }
val pcr_addr = addr(io.cpu(0).pcr_req.bits.addr.width-1, 0)
val pcr_coreid = if (ncores == 1) UFix(0) else addr(20+log2Up(ncores),20)
val pcr_wdata = packet_ram(0)
val bad_mem_packet = size(OFFSET_BITS-1-3,0).orR || addr(OFFSET_BITS-1-3,0).orR
val nack = Mux(cmd === cmd_readmem || cmd === cmd_writemem, bad_mem_packet,
Mux(cmd === cmd_readcr || cmd === cmd_writecr, size != UFix(1),
Bool(true)))
val tx_count = Reg(resetVal = UFix(0, rx_count_w))
val tx_subword_count = tx_count(log2Up(short_request_bits/w)-1,0)
val tx_word_count = tx_count(rx_count_w-1, log2Up(short_request_bits/w))
val packet_ram_raddr = tx_word_count(log2Up(packet_ram_depth)-1,0) - UFix(1)
when (io.host.out.valid && io.host.out.ready) {
tx_count := tx_count + UFix(1)
}
val rx_done = rx_word_done && Mux(rx_word_count === UFix(0), next_cmd != cmd_writemem && next_cmd != cmd_writecr, rx_word_count === size || rx_word_count(log2Up(packet_ram_depth)-1,0) === UFix(0))
val tx_size = Mux(!nack && (cmd === cmd_readmem || cmd === cmd_readcr || cmd === cmd_writecr), size, UFix(0))
val tx_done = io.host.out.ready && tx_subword_count.andR && (tx_word_count === tx_size || tx_word_count > UFix(0) && packet_ram_raddr.andR)
val mem_acked = Reg(resetVal = Bool(false))
val mem_gxid = Reg() { Bits() }
val mem_needs_ack = Reg() { Bool() }
val mem_nacked = Reg(resetVal = Bool(false))
when (io.mem.xact_rep.valid) {
mem_acked := Bool(true)
mem_gxid := io.mem.xact_rep.bits.global_xact_id
mem_needs_ack := io.mem.xact_rep.bits.require_ack
}
io.mem.xact_rep.ready := Bool(true)
when (io.mem.xact_abort.valid) { mem_nacked := Bool(true) }
io.mem.xact_abort.ready := Bool(true)
val state_rx :: state_pcr_req :: state_pcr_resp :: state_mem_req :: state_mem_wdata :: state_mem_wresp :: state_mem_rdata :: state_mem_finish :: state_tx :: Nil = Enum(9) { UFix() }
val state = Reg(resetVal = state_rx)
when (state === state_rx && rx_done) {
val rx_cmd = Mux(rx_word_count === UFix(0), next_cmd, cmd)
state := Mux(rx_cmd === cmd_readmem || rx_cmd === cmd_writemem, state_mem_req,
Mux(rx_cmd === cmd_readcr || rx_cmd === cmd_writecr, state_pcr_req,
state_tx))
}
val mem_cnt = Reg(resetVal = UFix(0, log2Up(REFILL_CYCLES)))
val x_init = new Queue(1)(new TransactionInit)
when (state === state_mem_req && x_init.io.enq.ready) {
state := Mux(cmd === cmd_writemem, state_mem_wdata, state_mem_rdata)
}
when (state === state_mem_wdata && io.mem.xact_init_data.ready) {
when (mem_cnt.andR) {
state := state_mem_wresp
}
mem_cnt := mem_cnt + UFix(1)
}
when (state === state_mem_wresp) {
when (mem_nacked) {
state := state_mem_req
mem_nacked := Bool(false)
}
when (mem_acked) {
state := state_mem_finish
mem_acked := Bool(false)
}
}
when (state === state_mem_rdata) {
when (mem_nacked) {
state := state_mem_req
mem_nacked := Bool(false)
}
when (io.mem.xact_rep.valid) {
when (mem_cnt.andR) {
state := state_mem_finish
}
mem_cnt := mem_cnt + UFix(1)
}
mem_acked := Bool(false)
}
when (state === state_mem_finish && io.mem.xact_finish.ready) {
state := Mux(cmd === cmd_readmem || pos === UFix(1), state_tx, state_rx)
pos := pos - UFix(1)
addr := addr + UFix(1 << OFFSET_BITS-3)
}
when (state === state_tx && tx_done) {
when (tx_word_count === tx_size) {
rx_count := UFix(0)
tx_count := UFix(0)
}
state := Mux(cmd === cmd_readmem && pos != UFix(0), state_mem_req, state_rx)
}
var mem_req_data: Bits = null
for (i <- 0 until MEM_DATA_BITS/short_request_bits) {
val idx = Cat(mem_cnt, UFix(i, log2Up(MEM_DATA_BITS/short_request_bits)))
when (state === state_mem_rdata && io.mem.xact_rep.valid) {
packet_ram(idx) := io.mem.xact_rep.bits.data((i+1)*short_request_bits-1, i*short_request_bits)
}
mem_req_data = Cat(packet_ram(idx), mem_req_data)
}
x_init.io.enq.valid := state === state_mem_req
val init_addr = addr.toUFix >> UFix(OFFSET_BITS-3)
x_init.io.enq.bits := Mux(cmd === cmd_writemem, co.getUncachedWriteTransactionInit(init_addr, UFix(0)), co.getUncachedReadTransactionInit(init_addr, UFix(0)))
io.mem.xact_init <> x_init.io.deq
io.mem.xact_init_data.valid:= state === state_mem_wdata
io.mem.xact_init_data.bits.data := mem_req_data
io.mem.xact_finish.valid := (state === state_mem_finish) && mem_needs_ack
io.mem.xact_finish.bits.global_xact_id := mem_gxid
io.mem.probe_req.ready := Bool(false)
io.mem.probe_rep.valid := Bool(false)
io.mem.probe_rep_data.valid := Bool(false)
io.mem.incoherent := Bool(true)
val pcrReadData = Vec(ncores) { Reg() { Bits(width = io.cpu(0).pcr_rep.bits.getWidth) } }
for (i <- 0 until ncores) {
val my_reset = Reg(resetVal = Bool(true))
val my_ipi = Reg(resetVal = Bool(false))
val cpu = io.cpu(i)
val me = pcr_coreid === UFix(i)
cpu.pcr_req.valid := state === state_pcr_req && me && pcr_addr != PCR_RESET
cpu.pcr_req.bits.rw := cmd === cmd_writecr
cpu.pcr_req.bits.addr := pcr_addr
cpu.pcr_req.bits.data := pcr_wdata
cpu.reset := my_reset
when (cpu.ipi_rep.ready) {
my_ipi := Bool(false)
}
cpu.ipi_rep.valid := my_ipi
cpu.ipi_req.ready := Bool(true)
for (j <- 0 until ncores) {
when (io.cpu(j).ipi_req.valid && io.cpu(j).ipi_req.bits === UFix(i)) {
my_ipi := Bool(true)
}
}
when (cpu.pcr_req.valid && cpu.pcr_req.ready) {
state := state_pcr_resp
}
when (state === state_pcr_req && me && pcr_addr === PCR_RESET) {
when (cmd === cmd_writecr) {
my_reset := pcr_wdata(0)
}
pcrReadData(i) := my_reset.toBits
state := state_tx
}
cpu.pcr_rep.ready := Bool(true)
when (cpu.pcr_rep.valid) {
pcrReadData(i) := cpu.pcr_rep.bits
state := state_tx
}
}
val tx_cmd = Mux(nack, cmd_nack, cmd_ack)
val tx_cmd_ext = Cat(Bits(0, 4-tx_cmd.getWidth), tx_cmd)
val tx_header = Cat(addr, seqno, tx_size, tx_cmd_ext)
val tx_data = Mux(tx_word_count === UFix(0), tx_header,
Mux(cmd === cmd_readcr || cmd === cmd_writecr, pcrReadData(pcr_coreid),
packet_ram(packet_ram_raddr)))
io.host.in.ready := state === state_rx
io.host.out.valid := state === state_tx
io.host.out.bits := tx_data >> Cat(tx_count(log2Up(short_request_bits/w)-1,0), Bits(0, log2Up(w)))
}