From 1b6355c89574c42c5b5f8014b994cf26dae4737d Mon Sep 17 00:00:00 2001
From: Steve Reinhardt <steve.reinhardt@amd.com>
Date: Sun, 17 Jan 2016 18:27:46 -0800
Subject: cpu. arch: add initiateMemRead() to ExecContext interface

For historical reasons, the ExecContext interface had a single
function, readMem(), that did two different things depending on
whether the ExecContext supported atomic memory mode (i.e.,
AtomicSimpleCPU) or timing memory mode (all the other models).
In the former case, it actually performed a memory read; in the
latter case, it merely initiated a read access, and the read
completion did not happen until later when a response packet
arrived from the memory system.

This led to some confusing things, including timing accesses
being required to provide a pointer for the return data even
though that pointer was only used in atomic mode.

This patch splits this interface, adding a new initiateMemRead()
function to the ExecContext interface to replace the timing-mode
use of readMem().

For consistency and clarity, the readMemTiming() helper function
in the ISA definitions is renamed to initiateMemRead() as well.
For x86, where the access size is passed in explicitly, we can
also get rid of the data parameter at this level.  For other ISAs,
where the access size is determined from the type of the data
parameter, we have to keep the parameter for that purpose.
---
 src/arch/arm/isa/templates/mem.isa    | 8 +++-----
 src/arch/arm/isa/templates/mem64.isa  | 2 +-
 src/arch/arm/isa/templates/neon64.isa | 5 +----
 3 files changed, 5 insertions(+), 10 deletions(-)

(limited to 'src/arch/arm')

diff --git a/src/arch/arm/isa/templates/mem.isa b/src/arch/arm/isa/templates/mem.isa
index bac1cd211..51f598f50 100644
--- a/src/arch/arm/isa/templates/mem.isa
+++ b/src/arch/arm/isa/templates/mem.isa
@@ -438,7 +438,8 @@ def template LoadInitiateAcc {{
         if (%(predicate_test)s)
         {
             if (fault == NoFault) {
-                fault = readMemTiming(xc, traceData, EA, Mem, memAccessFlags);
+                fault = initiateMemRead(xc, traceData, EA, Mem,
+                                        memAccessFlags);
             }
         } else {
             xc->setPredicate(false);
@@ -461,13 +462,10 @@ def template NeonLoadInitiateAcc {{
         %(op_rd)s;
         %(ea_code)s;
 
-        MemUnion memUnion;
-        uint8_t *dataPtr = memUnion.bytes;
-
         if (%(predicate_test)s)
         {
             if (fault == NoFault) {
-                fault = xc->readMem(EA, dataPtr, %(size)d, memAccessFlags);
+                fault = xc->initiateMemRead(EA, %(size)d, memAccessFlags);
             }
         } else {
             xc->setPredicate(false);
diff --git a/src/arch/arm/isa/templates/mem64.isa b/src/arch/arm/isa/templates/mem64.isa
index 72ee882a7..e831f17a5 100644
--- a/src/arch/arm/isa/templates/mem64.isa
+++ b/src/arch/arm/isa/templates/mem64.isa
@@ -191,7 +191,7 @@ def template Load64InitiateAcc {{
         %(ea_code)s;
 
         if (fault == NoFault) {
-            fault = readMemTiming(xc, traceData, EA, Mem, memAccessFlags);
+            fault = initiateMemRead(xc, traceData, EA, Mem, memAccessFlags);
         }
 
         return fault;
diff --git a/src/arch/arm/isa/templates/neon64.isa b/src/arch/arm/isa/templates/neon64.isa
index 19dd50910..6356073c5 100644
--- a/src/arch/arm/isa/templates/neon64.isa
+++ b/src/arch/arm/isa/templates/neon64.isa
@@ -313,11 +313,8 @@ def template NeonLoadInitiateAcc64 {{
         %(op_rd)s;
         %(ea_code)s;
 
-        MemUnion memUnion;
-        uint8_t *dataPtr = memUnion.bytes;
-
         if (fault == NoFault) {
-            fault = xc->readMem(EA, dataPtr, accSize, memAccessFlags);
+            fault = xc->initiateMemRead(EA, accSize, memAccessFlags);
         }
 
         return fault;
-- 
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