riscv/rocket-chip
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WIP on priv-1.10

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This commit is contained in:
Andrew Waterman
2017-02-27 14:27:19 -08:00
parent 43dea38ee9
commit db0a02b78e
8 changed files with 101 additions and 111 deletions
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121
src/main/scala/rocket/CSR.scala
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@ -18,11 +18,13 @@ class MStatus extends Bundle {
val prv = UInt(width = PRV.SZ) // not truly part of mstatus, but convenient
val sd = Bool()
val zero3 = UInt(width = 31)
val zero2 = UInt(width = 27)
val sxl = UInt(width = 2)
val uxl = UInt(width = 2)
val sd_rv32 = Bool()
val zero2 = UInt(width = 2)
val vm = UInt(width = 5)
val zero1 = UInt(width = 4)
val zero1 = UInt(width = 9)
val tw = Bool()
val tvm = Bool()
val mxr = Bool()
val pum = Bool()
val mprv = Bool()
@ -78,8 +80,18 @@ class MIP extends Bundle {
}
class PTBR(implicit p: Parameters) extends CoreBundle()(p) {
require(maxPAddrBits - pgIdxBits + asIdBits <= xLen)
val asid = UInt(width = asIdBits)
def pgLevelsToMode(i: Int) = (xLen, i) match {
case (32, 2) => 1
case (64, x) if x >= 3 && x <= 6 => x + 5
}
val (modeBits, maxASIdBits) = xLen match {
case 32 => (1, 9)
case 64 => (4, 16)
}
require(modeBits + maxASIdBits + maxPAddrBits - pgIdxBits == xLen)
val mode = UInt(width = modeBits)
val asid = UInt(width = maxASIdBits)
val ppn = UInt(width = maxPAddrBits - pgIdxBits)
}
@ -112,12 +124,12 @@ object CSR
}
val firstCtr = CSRs.cycle
val firstHPC = CSRs.hpmcounter3
val firstHPE = CSRs.mhpmevent3
val firstMHPC = CSRs.mhpmcounter3
val firstHPM = 3
val firstHPC = CSRs.cycle + firstHPM
val firstHPE = CSRs.mucounteren + firstHPM
val firstMHPC = CSRs.mcycle + firstHPM
val nHPM = 29
val nCtr = firstHPM + nHPM
val nCtr = 32
val nHPM = nCtr - firstHPM
}
class CSRFileIO(implicit p: Parameters) extends CoreBundle
@ -200,6 +212,7 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
val exception = io.exception || io.csr_xcpt
val reg_debug = Reg(init=Bool(false))
val effective_prv = Cat(reg_debug, reg_mstatus.prv)
val reg_dpc = Reg(UInt(width = vaddrBitsExtended))
val reg_dscratch = Reg(UInt(width = xLen))
@ -225,8 +238,8 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
case Some(addr) => Reg(init=UInt(addr, mtvecWidth))
case None => Reg(UInt(width = mtvecWidth))
}
val reg_mucounteren = Reg(UInt(width = 32))
val reg_mscounteren = Reg(UInt(width = 32))
val reg_mcounteren = Reg(UInt(width = 32))
val reg_scounteren = Reg(UInt(width = 32))
val delegable_counters = (BigInt(1) << (nPerfCounters + CSR.firstHPM)) - 1
val reg_sepc = Reg(UInt(width = vaddrBitsExtended))
@ -250,12 +263,12 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
val read_mip = mip.asUInt & supported_interrupts
val pending_interrupts = read_mip & reg_mie
val m_interrupts = Mux(!reg_debug && (reg_mstatus.prv < PRV.M || (reg_mstatus.prv === PRV.M && reg_mstatus.mie)), pending_interrupts & ~reg_mideleg, UInt(0))
val s_interrupts = Mux(!reg_debug && (reg_mstatus.prv < PRV.S || (reg_mstatus.prv === PRV.S && reg_mstatus.sie)), pending_interrupts & reg_mideleg, UInt(0))
val m_interrupts = Mux(reg_mstatus.prv <= PRV.S || (reg_mstatus.prv === PRV.M && reg_mstatus.mie), pending_interrupts & ~reg_mideleg, UInt(0))
val s_interrupts = Mux(m_interrupts === 0 && (reg_mstatus.prv < PRV.S || (reg_mstatus.prv === PRV.S && reg_mstatus.sie)), pending_interrupts & reg_mideleg, UInt(0))
val all_interrupts = m_interrupts | s_interrupts
val interruptMSB = BigInt(1) << (xLen-1)
val interruptCause = UInt(interruptMSB) + PriorityEncoder(all_interrupts)
io.interrupt := all_interrupts.orR && !io.singleStep || reg_singleStepped
io.interrupt := all_interrupts.orR && !reg_debug && !io.singleStep || reg_singleStepped
io.interrupt_cause := interruptCause
io.bp := reg_bp take nBreakpoints
@ -332,7 +345,6 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
val read_sie = reg_mie & reg_mideleg
val read_sip = read_mip & reg_mideleg
val read_sstatus = Wire(init=io.status)
read_sstatus.vm := 0
read_sstatus.mprv := 0
read_sstatus.mpp := 0
read_sstatus.hpp := 0
@ -350,11 +362,11 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
read_mapping += CSRs.sptbr -> reg_sptbr.asUInt
read_mapping += CSRs.sepc -> reg_sepc.sextTo(xLen)
read_mapping += CSRs.stvec -> reg_stvec.sextTo(xLen)
read_mapping += CSRs.mscounteren -> reg_mscounteren
read_mapping += CSRs.scounteren -> reg_scounteren
}
if (usingUser) {
read_mapping += CSRs.mucounteren -> reg_mucounteren
read_mapping += CSRs.mcounteren -> reg_mcounteren
read_mapping += CSRs.cycle -> reg_cycle
read_mapping += CSRs.instret -> reg_instret
}
@ -379,9 +391,7 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
val addr_valid = decoded_addr.values.reduce(_||_)
val fp_csr = if (usingFPU) decoded_addr.filterKeys(fp_csrs contains _ ).values reduce(_||_) else Bool(false)
val hpm_csr = if (usingUser) io.rw.addr >= CSR.firstCtr && io.rw.addr < CSR.firstCtr + CSR.nCtr else Bool(false)
val hpm_en = reg_debug || reg_mstatus.prv === PRV.M ||
(reg_mstatus.prv === PRV.S && reg_mscounteren(io.rw.addr(log2Ceil(CSR.nCtr)-1, 0))) ||
(reg_mstatus.prv === PRV.U && reg_mucounteren(io.rw.addr(log2Ceil(CSR.nCtr)-1, 0)))
val hpm_en = effective_prv > PRV.S || (reg_mcounteren & Mux((!usingVM).B || reg_mstatus.prv === PRV.S, delegable_counters.U, reg_scounteren))(io.rw.addr(log2Ceil(CSR.nCtr)-1, 0))
val csr_addr_priv = io.rw.addr(9,8)
val debug_csr_mask = 0x090 // only debug CSRs have address bits 7 and 4 set
@ -392,25 +402,37 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
val read_only = io.rw.addr(11,10).andR
val wen = cpu_wen && priv_sufficient && !read_only
val wdata = (Mux(io.rw.cmd.isOneOf(CSR.S, CSR.C), io.rw.rdata, UInt(0)) |
Mux(io.rw.cmd =/= CSR.C, io.rw.wdata, UInt(0))) &
val wdata = (Mux(io.rw.cmd.isOneOf(CSR.S, CSR.C), io.rw.rdata, UInt(0)) | io.rw.wdata) &
~Mux(io.rw.cmd === CSR.C, io.rw.wdata, UInt(0))
val do_system_insn = priv_sufficient && system_insn
val opcode = UInt(1) << io.rw.addr(2,0)
val insn_call = do_system_insn && opcode(0)
val insn_rs2 = io.rw.addr(5)
val insn_call = do_system_insn && !insn_rs2 && opcode(0)
val insn_break = do_system_insn && opcode(1)
val insn_ret = do_system_insn && opcode(2)
val insn_sfence_vm = do_system_insn && opcode(4)
val insn_wfi = do_system_insn && opcode(5)
val allow_wfi = effective_prv > PRV.S || !reg_mstatus.tw
val want_wfi = do_system_insn && opcode(5)
val insn_wfi = want_wfi && allow_wfi
val allow_sfence_vma = effective_prv > PRV.S || !reg_mstatus.tvm
val want_sfence_vma = do_system_insn && insn_rs2
val insn_sfence_vma = want_sfence_vma && allow_sfence_vma
val allow_fcsr = io.status.fs.orR && reg_misa('f'-'a')
io.csr_xcpt := (cpu_wen && read_only) ||
(cpu_ren && (!priv_sufficient || !addr_valid || (hpm_csr && !hpm_en) || (fp_csr && !(io.status.fs.orR && reg_misa('f'-'a'))))) ||
(cpu_ren &&
(!priv_sufficient ||
!addr_valid ||
(if (usingVM) decoded_addr(CSRs.sptbr) && !allow_sfence_vma else false.B) ||
(hpm_csr && !hpm_en) ||
(fp_csr && !allow_fcsr))) ||
(system_insn && !priv_sufficient) ||
insn_call || insn_break
insn_call || insn_break ||
want_wfi && !allow_wfi ||
want_sfence_vma && !allow_sfence_vma
when (insn_wfi) { reg_wfi := true }
when (pending_interrupts.orR) { reg_wfi := false }
when (pending_interrupts.orR || exception) { reg_wfi := false }
val cause =
Mux(!io.csr_xcpt, io.cause,
@ -421,12 +443,12 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
val causeIsDebugTrigger = !cause(xLen-1) && cause_lsbs === CSR.debugTriggerCause
val causeIsDebugBreak = !cause(xLen-1) && insn_break && Cat(reg_dcsr.ebreakm, reg_dcsr.ebreakh, reg_dcsr.ebreaks, reg_dcsr.ebreaku)(reg_mstatus.prv)
val trapToDebug = Bool(usingDebug) && (reg_singleStepped || causeIsDebugInt || causeIsDebugTrigger || causeIsDebugBreak || reg_debug)
val delegate = Bool(usingVM) && reg_mstatus.prv < PRV.M && Mux(cause(xLen-1), reg_mideleg(cause_lsbs), reg_medeleg(cause_lsbs))
val delegate = Bool(usingVM) && reg_mstatus.prv <= PRV.S && Mux(cause(xLen-1), reg_mideleg(cause_lsbs), reg_medeleg(cause_lsbs))
val debugTVec = Mux(reg_debug, UInt(0x808), UInt(0x800))
val tvec = Mux(trapToDebug, debugTVec, Mux(delegate, reg_stvec.sextTo(vaddrBitsExtended), reg_mtvec))
val epc = Mux(csr_debug, reg_dpc, Mux(Bool(usingVM) && !csr_addr_priv(1), reg_sepc, reg_mepc))
io.fatc := insn_sfence_vm
io.evec := Mux(exception, tvec, epc)
io.fatc := insn_sfence_vma
io.evec := Mux(insn_ret, epc, tvec)
io.ptbr := reg_sptbr
io.eret := insn_ret
io.singleStep := reg_dcsr.step && !reg_debug
@ -434,6 +456,8 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
io.status.sd := io.status.fs.andR || io.status.xs.andR
io.status.debug := reg_debug
io.status.isa := reg_misa
io.status.uxl := (if (usingUser) log2Ceil(xLen) - 4 else 0)
io.status.sxl := (if (usingVM) log2Ceil(xLen) - 4 else 0)
if (xLen == 32)
io.status.sd_rv32 := io.status.sd
@ -508,21 +532,17 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
if (usingUser) {
reg_mstatus.mprv := new_mstatus.mprv
reg_mstatus.mpp := trimPrivilege(new_mstatus.mpp)
reg_mstatus.mxr := new_mstatus.mxr
if (usingVM) {
reg_mstatus.mxr := new_mstatus.mxr
reg_mstatus.pum := new_mstatus.pum
reg_mstatus.spp := new_mstatus.spp
reg_mstatus.spie := new_mstatus.spie
reg_mstatus.sie := new_mstatus.sie
reg_mstatus.tw := new_mstatus.tw
reg_mstatus.tvm := new_mstatus.tvm
}
}
if (usingVM) {
require(if (xLen == 32) pgLevels == 2 else pgLevels > 2 && pgLevels < 6)
val vm_on = 6 + pgLevels // TODO Sv48 support should imply Sv39 support
when (new_mstatus.vm === 0) { reg_mstatus.vm := 0 }
when (new_mstatus.vm === vm_on) { reg_mstatus.vm := vm_on }
}
if (usingVM || usingFPU) reg_mstatus.fs := Fill(2, new_mstatus.fs.orR)
if (usingRoCC) reg_mstatus.xs := Fill(2, new_mstatus.xs.orR)
}
@ -554,7 +574,7 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
writeCounter(CSRs.mcycle, reg_cycle, wdata)
writeCounter(CSRs.minstret, reg_instret, wdata)
if (usingFPU) {
if (usingFPU) when (allow_fcsr) {
when (decoded_addr(CSRs.fflags)) { reg_fflags := wdata }
when (decoded_addr(CSRs.frm)) { reg_frm := wdata }
when (decoded_addr(CSRs.fcsr)) { reg_fflags := wdata; reg_frm := wdata >> reg_fflags.getWidth }
@ -586,19 +606,28 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
val new_sip = new MIP().fromBits(wdata)
reg_mip.ssip := new_sip.ssip
}
when (decoded_addr(CSRs.sptbr) && allow_sfence_vma) {
val new_sptbr = new PTBR().fromBits(wdata)
val valid_mode = new_sptbr.pgLevelsToMode(pgLevels)
when (new_sptbr.mode === 0) { reg_sptbr.mode := 0 }
when (new_sptbr.mode === valid_mode) { reg_sptbr.mode := valid_mode }
when (new_sptbr.mode === 0 || new_sptbr.mode === valid_mode) {
reg_sptbr.ppn := new_sptbr.ppn(ppnBits-1,0)
if (asIdBits > 0) reg_sptbr.asid := new_sptbr.asid(asIdBits-1,0)
}
}
when (decoded_addr(CSRs.sie)) { reg_mie := (reg_mie & ~reg_mideleg) | (wdata & reg_mideleg) }
when (decoded_addr(CSRs.sscratch)) { reg_sscratch := wdata }
when (decoded_addr(CSRs.sptbr)) { reg_sptbr.ppn := wdata(ppnBits-1,0) }
when (decoded_addr(CSRs.sepc)) { reg_sepc := formEPC(wdata) }
when (decoded_addr(CSRs.stvec)) { reg_stvec := wdata >> 2 << 2 }
when (decoded_addr(CSRs.scause)) { reg_scause := wdata & UInt((BigInt(1) << (xLen-1)) + 31) /* only implement 5 LSBs and MSB */ }
when (decoded_addr(CSRs.sbadaddr)) { reg_sbadaddr := wdata(vaddrBitsExtended-1,0) }
when (decoded_addr(CSRs.mideleg)) { reg_mideleg := wdata & delegable_interrupts }
when (decoded_addr(CSRs.medeleg)) { reg_medeleg := wdata & delegable_exceptions }
when (decoded_addr(CSRs.mscounteren)) { reg_mscounteren := wdata & UInt(delegable_counters) }
when (decoded_addr(CSRs.scounteren)) { reg_scounteren := wdata & UInt(delegable_counters) }
}
if (usingUser) {
when (decoded_addr(CSRs.mucounteren)) { reg_mucounteren := wdata & UInt(delegable_counters) }
when (decoded_addr(CSRs.mcounteren)) { reg_mcounteren := wdata & UInt(delegable_counters) }
}
if (nBreakpoints > 0) {
when (decoded_addr(CSRs.tselect)) { reg_tselect := wdata }
@ -623,11 +652,11 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
if (!usingVM) {
reg_mideleg := 0
reg_medeleg := 0
reg_mscounteren := 0
reg_scounteren := 0
}
if (!usingUser) {
reg_mucounteren := 0
reg_mcounteren := 0
}
reg_sptbr.asid := 0