riscv/rocket-chip
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Make SEIP writable

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This commit is contained in:
Andrew Waterman 2017-03-27 16:35:47 -07:00
parent c7c357e716
commit d42d8aaea7
1 changed files with 16 additions and 4 deletions
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20
src/main/scala/rocket/CSR.scala
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@ -291,6 +291,8 @@ class CSRFile(perfEventSets: EventSets = new EventSets(Seq()))(implicit p: Param
val hpm_mask = reg_mcounteren & Mux((!usingVM).B || reg_mstatus.prv === PRV.S, delegable_counters.U, reg_scounteren)
val mip = Wire(init=reg_mip)
// seip is the OR of reg_mip.seip and the actual line from the PLIC
io.interrupts.seip.foreach { mip.seip := reg_mip.seip || RegNext(_) }
mip.rocc := io.rocc_interrupt
val read_mip = mip.asUInt & supported_interrupts
@ -430,8 +432,7 @@ class CSRFile(perfEventSets: EventSets = new EventSets(Seq()))(implicit p: Param
}
val decoded_addr = read_mapping map { case (k, v) => k -> (io.rw.addr === k) }
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 wdata = readModifyWriteCSR(io.rw.cmd, io.rw.rdata, io.rw.wdata)
val system_insn = io.rw.cmd === CSR.I
val opcode = UInt(1) << io.rw.addr(2,0)
@ -588,10 +589,15 @@ class CSRFile(perfEventSets: EventSets = new EventSets(Seq()))(implicit p: Param
reg_misa := ~(~wdata | (!f << ('d' - 'a'))) & mask | reg_misa & ~mask
}
when (decoded_addr(CSRs.mip)) {
val new_mip = new MIP().fromBits(wdata)
// MIP should be modified based on the value in reg_mip, not the value
// in read_mip, since read_mip.seip is the OR of reg_mip.seip and
// io.interrupts.seip. We don't want the value on the PLIC line to
// inadvertently be OR'd into read_mip.seip.
val new_mip = readModifyWriteCSR(io.rw.cmd, reg_mip.asUInt, io.rw.wdata).asTypeOf(new MIP)
if (usingVM) {
reg_mip.ssip := new_mip.ssip
reg_mip.stip := new_mip.stip
reg_mip.seip := new_mip.seip
}
}
when (decoded_addr(CSRs.mie)) { reg_mie := wdata & supported_interrupts }
@ -691,7 +697,10 @@ class CSRFile(perfEventSets: EventSets = new EventSets(Seq()))(implicit p: Param
}
}
reg_mip := io.interrupts
reg_mip.lip zip io.interrupts.lip foreach { case (r, i) => r := i }
reg_mip.mtip := io.interrupts.mtip
reg_mip.msip := io.interrupts.msip
reg_mip.meip := io.interrupts.meip
reg_dcsr.debugint := io.interrupts.debug
if (!usingVM) {
@ -734,6 +743,9 @@ class CSRFile(perfEventSets: EventSets = new EventSets(Seq()))(implicit p: Param
}
}
def readModifyWriteCSR(cmd: UInt, rdata: UInt, wdata: UInt) =
(Mux(cmd.isOneOf(CSR.S, CSR.C), rdata, UInt(0)) | wdata) & ~Mux(cmd === CSR.C, wdata, UInt(0))
def legalizePrivilege(priv: UInt): UInt =
if (usingVM) Mux(priv === PRV.H, PRV.U, priv)
else if (usingUser) Fill(2, priv(0))