Cheri-research/Toooba
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Implement CCall, hopefully as well as CJALR.

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This passes the unmodified TestRIG routine for CHERI Control Flow, which is very promising indeed!
There are some cases that are not covered there, but a lot is covered.
This commit is contained in:
jon
2020-04-14 18:10:53 +01:00
parent 72dc8f8bad
commit 9685bf1931
3 changed files with 53 additions and 28 deletions
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41
src_Core/RISCY_OOO/procs/lib/Decode.bsv
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@@ -823,21 +823,22 @@ function DecodeResult decode(Instruction inst);
f7_cap_TwoSrc: begin
case (rd)
rd_cap_CCall: begin
// TODO
// dInst.capChecks.src1_tag = True;
// dInst.capChecks.src2_tag = True;
// dInst.capChecks.src1_sealed = True;
// dInst.capChecks.src2_sealed = True;
// dInst.capChecks.src1_src2_types_match = True;
// dInst.capChecks.src1_permit_x = True;
// dInst.capChecks.src2_no_permit_x = True;
// dInst.capChecks.src1_permit_ccall = True;
// dInst.capChecks.src2_permit_ccall = True;
dInst.capChecks.src1_tag = True;
dInst.capChecks.src2_tag = True;
dInst.capChecks.src1_sealed = True;
dInst.capChecks.src2_sealed = True;
dInst.capChecks.src1_src2_types_match = True;
dInst.capChecks.src1_permit_x = True;
dInst.capChecks.src2_no_permit_x = True;
dInst.capChecks.src1_permit_ccall = True;
dInst.capChecks.src2_permit_ccall = True;
// regs.rd = Invalid;
// regs.src1 = Valid(tagged Gpr rs1);
// regs.src2 = Valid(tagged Gpr rs2);
// dInst.imm = Invalid;
dInst.iType = Jr;
dInst.execFunc = tagged Br AT;
regs.dst = Valid(tagged Gpr 31);
regs.src1 = Valid(tagged Gpr rs1);
regs.src2 = Valid(tagged Gpr rs2);
dInst.imm = Invalid;
end
default: begin
illegalInst = True;
@@ -857,7 +858,7 @@ function DecodeResult decode(Instruction inst);
regs.src1 = Valid(tagged Gpr rs1);
regs.src2 = Valid(tagged Gpr rs2);
dInst.imm = Invalid;
dInst.execFunc = CapModify (Unseal);
dInst.execFunc = CapModify (Unseal (Src1));
end
f7_cap_CTestSubset: begin
dInst.iType = Alu;
@@ -1036,16 +1037,16 @@ function DecodeResult decode(Instruction inst);
dInst.execFunc = CapInspect (GetPerm);
end
f5rs2_cap_CJALR: begin
dInst.capChecks.src1_tag = True;
dInst.capChecks.src1_permit_x = True;
dInst.capChecks.src1_unsealed = True;
dInst.iType = Jr;
dInst.execFunc = tagged Br AT;
regs.dst = Valid(tagged Gpr rd);
regs.src1 = Valid(tagged Gpr rs1);
regs.src2 = Invalid;
dInst.imm = Invalid;
//dInst.scr = tagged Valid SCR_PCC;
dInst.execFunc = tagged Br AT;
dInst.capChecks.src1_tag = True;
dInst.capChecks.src1_permit_x = True;
dInst.capChecks.src1_unsealed = True;
end
f5rs2_cap_CGetType: begin
dInst.iType = Alu;

27
src_Core/RISCY_OOO/procs/lib/Exec.bsv
View File

@@ -110,8 +110,8 @@ function CapPipe capModify(CapPipe a, CapPipe b, CapModifyFunc func);
setAddr(a, addrSource == Src2Type ? (isSealed(b) ? zeroExtend(getType(b)) : -1) : getAddr(b)).value;
tagged Seal :
setType(a, truncate(getAddr(b)));
tagged Unseal :
setType(a, -1);
tagged Unseal .src :
setType(((src == Src1) ? a:b), -1);
tagged AndPerm :
setPerms(a, pack(getPerms(a)) & truncate(getAddr(b)));
tagged SetFlags :
@@ -213,7 +213,13 @@ function ExecResult basicExec(DecodedInst dInst, CapPipe rVal1, CapPipe rVal2, C
CapPipe data = nullCap;
Data csr_data = 0;
CapPipe addr = nullCap;
Bool cjalr = (dInst.iType == Jr) && dInst.capChecks.src1_tag;
Bool cjalr = False;
Bool ccall = False;
if (dInst.iType == Jr) begin
if (dInst.capChecks.src1_src2_types_match) ccall = True;
else if (dInst.capChecks.src1_tag) cjalr = True;
end
ControlFlow cf = ControlFlow{pc: pc, nextPc: 0, taken: False, newPcc: cjalr, mispredict: False};
CapPipe aluVal2 = rVal2;
@@ -223,11 +229,13 @@ function ExecResult basicExec(DecodedInst dInst, CapPipe rVal1, CapPipe rVal2, C
Data alu_result = alu(getAddr(rVal1), getAddr(aluVal2), alu_f);
Data inspect_result = capInspect(rVal1, aluVal2, dInst.execFunc.CapInspect);
CapPipe modify_result = capModify(rVal1, aluVal2, dInst.execFunc.CapModify);
CapModifyFunc modFunc = ccall ? (Unseal (Src1)):dInst.execFunc.CapModify;
CapPipe modify_result = capModify(rVal1, aluVal2, modFunc);
Maybe#(CapException) capException = capChecks(rVal1, aluVal2, dInst.capChecks); // TODO use this to throw exceptions
CapPipe cap_alu_result = case (dInst.execFunc) matches tagged CapInspect .x: nullWithAddr(inspect_result);
tagged CapModify .x: modify_result;
tagged Br .x: modify_result;
default: nullWithAddr(alu_result);
endcase;
@@ -240,9 +248,14 @@ function ExecResult basicExec(DecodedInst dInst, CapPipe rVal1, CapPipe rVal2, C
Addr fallthrough_incr = ((orig_inst [1:0] == 2'b11) ? 4 : 2);
CapPipe link_pcc = setAddrUnsafe(pcc, getAddr(pcc) + fallthrough_incr);
data = (case (dInst.iType)
St, Sc, Amo : rVal2;
J, Jr : (cjalr ? link_pcc : nullWithAddr(getAddr(link_pcc))); // could be computed with alu
data = (case (dInst.iType) matches
St : rVal2;
Sc : rVal2;
Amo : rVal2;
J : nullWithAddr(getAddr(link_pcc));
Jr &&& (ccall): cap_alu_result; // Depending on defaults falling through!
Jr &&& (cjalr): link_pcc;
Jr : nullWithAddr(getAddr(link_pcc));
Auipc : nullWithAddr(pc + fromMaybe(?, getDInstImm(dInst))); // could be computed with alu
Csr : rVal1;
default : cap_alu_result;

13
src_Core/RISCY_OOO/procs/lib/ProcTypes.bsv
View File

@@ -224,6 +224,13 @@ function Opcode unpackOpcode(Bit#(7) x);
endcase);
endfunction
/* If Bluespec never allows illegal values of sparse enumerated types, this function should replace the one above:
function Opcode unpackOpcode(Bit#(7) x);
Opcode test = unpack(x);
if (pack(test) != x) return Invalid;
else return test;
endfunction
*/
typedef enum {
// user standard CSRs
CSRfflags = 12'h001,
@@ -420,13 +427,17 @@ typedef enum {
Src2Type, Src2Addr
} AddrSource deriving(Bits, Eq, FShow);
typedef enum {
Src1, Src2
} SrcSelector deriving(Bits, Eq, FShow);
typedef union tagged {
ModifyOffsetFunc ModifyOffset;
Bool SetBounds;
void SpecialRW;
AddrSource SetAddr;
void Seal;
void Unseal;
SrcSelector Unseal;
void AndPerm;
void SetFlags;
void BuildCap;