arch-arm: fix routeToHyp for AArch64 in faults

This patch fixes several bugs in Fault classes "routeToHyp" member
function by which mode checking was not taking into account AArch64
execution state. For the particular case of SVC calls from NS EL0, this
prevented a correct routing to EL2 when HCR_EL2.TGE was set.

Change-Id: I5815fe6dcf4501f52bf92f61687ef6d6ef950e52
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22725
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>

1 files changed, 14 insertions, 18 deletions

diff --git a/src/arch/arm/faults.cc b/src/arch/arm/faults.cc
index dbad5bf66..85e9fa7e9 100644
--- a/src/arch/arm/faults.cc
+++ b/src/arch/arm/faults.cc
@@ -800,9 +800,9 @@ UndefinedInstruction::routeToHyp(ThreadContext *tc) const
     CPSR cpsr = tc->readMiscRegNoEffect(MISCREG_CPSR);
 
     // if in Hyp mode then stay in Hyp mode
-    toHyp  = scr.ns && (cpsr.mode == MODE_HYP);
+    toHyp  = scr.ns && (currEL(tc) == EL2);
     // if HCR.TGE is set to 1, take to Hyp mode through Hyp Trap vector
-    toHyp |= !inSecureState(scr, cpsr) && hcr.tge && (cpsr.mode == MODE_USER);
+    toHyp |= !inSecureState(scr, cpsr) && hcr.tge && (currEL(tc) == EL0);
     return toHyp;
 }
 
@@ -874,7 +874,7 @@ SupervisorCall::routeToHyp(ThreadContext *tc) const
     // if in Hyp mode then stay in Hyp mode
     toHyp  = scr.ns && (cpsr.mode == MODE_HYP);
     // if HCR.TGE is set to 1, take to Hyp mode through Hyp Trap vector
-    toHyp |= !inSecureState(scr, cpsr) && hcr.tge && (cpsr.mode == MODE_USER);
+    toHyp |= !inSecureState(scr, cpsr) && hcr.tge && (currEL(tc) == EL0);
     return toHyp;
 }
 
@@ -1283,16 +1283,15 @@ PrefetchAbort::routeToHyp(ThreadContext *tc) const
 
     SCR  scr  = tc->readMiscRegNoEffect(MISCREG_SCR);
     HCR  hcr  = tc->readMiscRegNoEffect(MISCREG_HCR);
-    CPSR cpsr = tc->readMiscRegNoEffect(MISCREG_CPSR);
     HDCR hdcr = tc->readMiscRegNoEffect(MISCREG_HDCR);
 
     // if in Hyp mode then stay in Hyp mode
-    toHyp  = scr.ns && (cpsr.mode == MODE_HYP);
+    toHyp = scr.ns && (currEL(tc) == EL2);
     // otherwise, check whether to take to Hyp mode through Hyp Trap vector
     toHyp |= (stage2 ||
-                ( (source ==               DebugEvent) && hdcr.tde && (cpsr.mode !=  MODE_HYP)) ||
-                ( (source == SynchronousExternalAbort) && hcr.tge  && (cpsr.mode == MODE_USER))
-             ) && !inSecureState(tc);
+              ((source == DebugEvent) && hdcr.tde && (currEL(tc) != EL2)) ||
+               ((source == SynchronousExternalAbort) && hcr.tge &&
+                (currEL(tc) == EL0))) && !inSecureState(tc);
     return toHyp;
 }
 
@@ -1344,21 +1343,18 @@ DataAbort::routeToHyp(ThreadContext *tc) const
 
     SCR  scr  = tc->readMiscRegNoEffect(MISCREG_SCR);
     HCR  hcr  = tc->readMiscRegNoEffect(MISCREG_HCR);
-    CPSR cpsr = tc->readMiscRegNoEffect(MISCREG_CPSR);
     HDCR hdcr = tc->readMiscRegNoEffect(MISCREG_HDCR);
 
     // if in Hyp mode then stay in Hyp mode
-    toHyp  = scr.ns && (cpsr.mode == MODE_HYP);
+    toHyp = scr.ns && (currEL(tc) == EL2);
     // otherwise, check whether to take to Hyp mode through Hyp Trap vector
     toHyp |= (stage2 ||
-                ( (cpsr.mode != MODE_HYP) && ( ((source == AsynchronousExternalAbort) && hcr.amo) ||
-                                               ((source == DebugEvent) && hdcr.tde) )
-                ) ||
-                ( (cpsr.mode == MODE_USER) && hcr.tge &&
-                  ((source == AlignmentFault)            ||
-                   (source == SynchronousExternalAbort))
-                )
-             ) && !inSecureState(tc);
+              ((currEL(tc) != EL2) &&
+               (((source == AsynchronousExternalAbort) && hcr.amo) ||
+                ((source == DebugEvent) && hdcr.tde))) ||
+               ((currEL(tc) == EL0) && hcr.tge &&
+                ((source == AlignmentFault) ||
+                 (source == SynchronousExternalAbort)))) && !inSecureState(tc);
     return toHyp;
 }