From c0d19391d423d16c5dc587c4946e8395b9c0db91 Mon Sep 17 00:00:00 2001
From: Mitch Hayenga <mitch.hayenga@arm.com>
Date: Mon, 29 Feb 2016 19:13:13 -0600
Subject: [PATCH] arm: Squash after returning from exceptions in v7

Properly done for the ERET instruction in v8, but not for v7.
Many control register changes are only visible after explicit
instruction synchronization barriers or exception entry/exit.
This means mode changing instructions should squash any
younger in-flight speculative instructions.
---
 src/arch/arm/isa/insts/data.isa     | 6 ++++--
 src/arch/arm/isa/insts/macromem.isa | 4 ++--
 src/arch/arm/isa/insts/misc.isa     | 3 ++-
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/arch/arm/isa/insts/data.isa b/src/arch/arm/isa/insts/data.isa
index 881676496..df5a8b51e 100644
--- a/src/arch/arm/isa/insts/data.isa
+++ b/src/arch/arm/isa/insts/data.isa
@@ -273,10 +273,12 @@ let {{
             '''
             buildImmDataInst(mnem + 's', code, flagType,
                              suffix = "ImmPclr", buildCc = False,
-                             instFlags = ["IsSerializeAfter","IsNonSpeculative"])
+                             instFlags = ["IsSerializeAfter","IsNonSpeculative",
+                                          "IsSquashAfter"])
             buildRegDataInst(mnem + 's', code, flagType,
                              suffix = "RegPclr", buildCc = False,
-                             instFlags = ["IsSerializeAfter","IsNonSpeculative"])
+                             instFlags = ["IsSerializeAfter","IsNonSpeculative",
+                                          "IsSquashAfter"])
 
     buildDataInst("and", "Dest = resTemp = Op1 & secondOp;")
     buildDataInst("eor", "Dest = resTemp = Op1 ^ secondOp;")
diff --git a/src/arch/arm/isa/insts/macromem.isa b/src/arch/arm/isa/insts/macromem.isa
index 8c1b26808..cc7366e2b 100644
--- a/src/arch/arm/isa/insts/macromem.isa
+++ b/src/arch/arm/isa/insts/macromem.isa
@@ -124,7 +124,7 @@ let {{
                                           'EA = URb + (up ? imm : -imm);',
                                        'predicate_test': condPredicateTest},
                                       ['IsMicroop','IsNonSpeculative',
-                                       'IsSerializeAfter'])
+                                       'IsSerializeAfter', 'IsSquashAfter'])
 
     microStrUopCode = "Mem = cSwap(URa_uw, ((CPSR)Cpsr).e);"
     microStrUopIop = InstObjParams('str_uop', 'MicroStrUop',
@@ -668,7 +668,7 @@ let {{
                                      {'code': microRetUopCode % 'URb',
                                       'predicate_test': predicateTest},
                                      ['IsMicroop', 'IsNonSpeculative',
-                                      'IsSerializeAfter'])
+                                      'IsSerializeAfter', 'IsSquashAfter'])
 
     setPCCPSRDecl = '''
                     CPSR cpsrOrCondCodes = URc;
diff --git a/src/arch/arm/isa/insts/misc.isa b/src/arch/arm/isa/insts/misc.isa
index c8b1de1d8..77c22e6ca 100644
--- a/src/arch/arm/isa/insts/misc.isa
+++ b/src/arch/arm/isa/insts/misc.isa
@@ -130,7 +130,8 @@ let {{
     eretIop = InstObjParams("eret", "Eret", "PredOp",
                            { "code": eretCode,
                              "predicate_test": predicateTest },
-                           ["IsNonSpeculative", "IsSerializeAfter"])
+                           ["IsNonSpeculative", "IsSerializeAfter",
+                            "IsSquashAfter"])
     header_output += BasicDeclare.subst(eretIop)
     decoder_output += BasicConstructor.subst(eretIop)
     exec_output += PredOpExecute.subst(eretIop)