arm: Correctly check translation mode (aarch64/aarch32)

According to the ARM ARM (see AArch32.TranslateAddress in the
pseudocode library), the TLB should be operating in aarch64 mode if
the EL0 is aarch32 and EL1 is aarch64. This is currently not the case
in gem5, which breaks 64/32 interprocessing. Update the check to match
the reference manual.

Change-Id: I6f1444d57c0e2eb5f8880f513f33a9197b7cb2ce
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Mitch Hayenga <mitch.hayenga@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>

diff --git a/src/arch/arm/tlb.cc b/src/arch/arm/tlb.cc
index 3fc3170481e54b025dd47f48b88003b58021da13..1f6910262cc567faa69d82f0ad2230f4c14c083c 100644 (file)
--- a/src/arch/arm/tlb.cc
+++ b/src/arch/arm/tlb.cc
@@ -1197,11 +1197,15 @@ TLB::updateMiscReg(ThreadContext *tc, ArmTranslationType tranType)
 
     DPRINTF(TLBVerbose, "TLB variables changed!\n");
     cpsr = tc->readMiscReg(MISCREG_CPSR);
+
     // Dependencies: SCR/SCR_EL3, CPSR
-    isSecure  = inSecureState(tc);
-    isSecure &= (tranType & HypMode)    == 0;
-    isSecure &= (tranType & S1S2NsTran) == 0;
-    aarch64 = !cpsr.width;
+    isSecure = inSecureState(tc) &&
+        !(tranType & HypMode) && !(tranType & S1S2NsTran);
+
+    const OperatingMode op_mode = (OperatingMode) (uint8_t)cpsr.mode;
+    aarch64 = opModeIs64(op_mode) ||
+        (opModeToEL(op_mode) == EL0 && ELIs64(tc, EL1));
+
     if (aarch64) {  // AArch64
         aarch64EL = (ExceptionLevel) (uint8_t) cpsr.el;
         switch (aarch64EL) {