arch-arm: Handle route to EL2 in Supervisor Trap

Supervisor Trap is supposed to be able to handle exceptions routed
to EL2, which is enabled by HCR_EL2.TGE. This fix adds routeToHyp()
function to Supervisor Trap to handle this, similar to that in
UndefinedFault, DataAbort, etc.

Change-Id: I1fcf9f2d445ecbc13c8f6d3b7d599728b0250ab7
Reviewed-by: Jack Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7961
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

diff --git a/src/arch/arm/faults.cc b/src/arch/arm/faults.cc
index d143056b17c16a92903e61a1cd3d39f943390a6f..27894e0c10a3af28672a17fba7bfc355f6806e6e 100644 (file)
--- a/src/arch/arm/faults.cc
+++ b/src/arch/arm/faults.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2012-2014, 2016-2017 ARM Limited
+ * Copyright (c) 2010, 2012-2014, 2016-2018 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -923,10 +923,37 @@ SecureMonitorCall::ec(ThreadContext *tc) const
     return (from64 ? EC_SMC_64 : vals.ec);
 }
 
+bool
+SupervisorTrap::routeToHyp(ThreadContext *tc) const
+{
+    bool toHyp = false;
+
+    SCR  scr  = tc->readMiscRegNoEffect(MISCREG_SCR_EL3);
+    HCR  hcr  = tc->readMiscRegNoEffect(MISCREG_HCR_EL2);
+    CPSR cpsr = tc->readMiscRegNoEffect(MISCREG_CPSR);
+
+    // if HCR.TGE is set to 1, take to Hyp mode through Hyp Trap vector
+    toHyp |= !inSecureState(scr, cpsr) && hcr.tge && (cpsr.el == EL0);
+    return toHyp;
+}
+
+uint32_t
+SupervisorTrap::iss() const
+{
+    // If SupervisorTrap is routed to hypervisor, iss field is 0.
+    if (hypRouted) {
+        return 0;
+    }
+    return issRaw;
+}
+
 ExceptionClass
 SupervisorTrap::ec(ThreadContext *tc) const
 {
-    return (overrideEc != EC_INVALID) ? overrideEc : vals.ec;
+    if (hypRouted)
+        return EC_UNKNOWN;
+    else
+        return (overrideEc != EC_INVALID) ? overrideEc : vals.ec;
 }
 
 ExceptionClass

diff --git a/src/arch/arm/faults.hh b/src/arch/arm/faults.hh
index fa6740a1ada84552020486d1fb3c84968780de7a..bec2c0e8ff7a42665288827607dd541b8ec99851 100644 (file)
--- a/src/arch/arm/faults.hh
+++ b/src/arch/arm/faults.hh
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2012-2013, 2016-2017 ARM Limited
+ * Copyright (c) 2010, 2012-2013, 2016-2018 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -335,6 +335,8 @@ class SupervisorTrap : public ArmFaultVals<SupervisorTrap>
         overrideEc(_overrideEc)
     {}
 
+    bool routeToHyp(ThreadContext *tc) const override;
+    uint32_t iss() const override;
     ExceptionClass ec(ThreadContext *tc) const override;
 };