Clock: Move the clock and related functions to ClockedObject

This patch moves the clock of the CPU, bus, and numerous devices to
the new class ClockedObject, that sits in between the SimObject and
MemObject in the class hierarchy. Although there are currently a fair
amount of MemObjects that do not make use of the clock, they
potentially should do so, e.g. the caches should at some point have
the same clock as the CPU, potentially with a 1:n ratio. This patch
does not introduce any new clock objects or object hierarchies
(clusters, clock domains etc), but is still a step in the direction of
having a more structured approach clock domains.

The most contentious part of this patch is the serialisation of clocks
that some of the modules (but not all) did previously. This
serialisation should not be needed as the clock is set through the
parameters even when restoring from the checkpoint. In other words,
the state is "stored" in the Python code that creates the modules.

The nextCycle methods are also simplified and the clock phase
parameter of the CPU is removed (this could be part of a clock object
once they are introduced).

4 files changed, 6 insertions, 35 deletions

diff --git a/src/dev/arm/RealView.py b/src/dev/arm/RealView.py
index 967267197..876188c12 100644
--- a/src/dev/arm/RealView.py
+++ b/src/dev/arm/RealView.py
@@ -118,7 +118,8 @@ class CpuLocalTimer(BasicPioDevice):
     gic = Param.Gic(Parent.any, "Gic to use for interrupting")
     int_num_timer = Param.UInt32("Interrrupt number used per-cpu to GIC")
     int_num_watchdog = Param.UInt32("Interrupt number for per-cpu watchdog to GIC")
-    clock = Param.Clock('1GHz', "Clock speed at which the timer counts")
+    # Override the default clock
+    clock = '1GHz'
 
 class PL031(AmbaIntDevice):
     type = 'PL031'
@@ -134,7 +135,8 @@ class Pl050(AmbaIntDevice):
 
 class Pl111(AmbaDmaDevice):
     type = 'Pl111'
-    clock = Param.Clock('24MHz', "Clock speed of the input")
+    # Override the default clock
+    clock = '24MHz'
     vnc   = Param.VncServer(Parent.any, "Vnc server for remote frame buffer display")
     amba_id = 0x00141111
 
diff --git a/src/dev/arm/pl111.cc b/src/dev/arm/pl111.cc
index 998644a8c..d79a1cf39 100644
--- a/src/dev/arm/pl111.cc
+++ b/src/dev/arm/pl111.cc
@@ -63,7 +63,7 @@ Pl111::Pl111(const Params *p)
       lcdRis(0), lcdMis(0),
       clcdCrsrCtrl(0), clcdCrsrConfig(0), clcdCrsrPalette0(0),
       clcdCrsrPalette1(0), clcdCrsrXY(0), clcdCrsrClip(0), clcdCrsrImsc(0),
-      clcdCrsrIcr(0), clcdCrsrRis(0), clcdCrsrMis(0), clock(p->clock),
+      clcdCrsrIcr(0), clcdCrsrRis(0), clcdCrsrMis(0),
       vncserver(p->vnc), bmp(NULL), width(LcdMaxWidth), height(LcdMaxHeight),
       bytesPerPixel(4), startTime(0), startAddr(0), maxAddr(0), curAddr(0),
       waterMark(0), dmaPendingNum(0), readEvent(this), fillFifoEvent(this),
@@ -512,26 +512,6 @@ Pl111::dmaDone()
         schedule(fillFifoEvent, nextCycle());
 }
 
-
-Tick
-Pl111::nextCycle()
-{
-    Tick nextTick = curTick() + clock - 1;
-    nextTick -= nextTick%clock;
-    return nextTick;
-}
-
-Tick
-Pl111::nextCycle(Tick beginTick)
-{
-    Tick nextTick = beginTick;
-    if (nextTick%clock!=0)
-        nextTick = nextTick - (nextTick%clock) + clock;
-
-    assert(nextTick >= curTick());
-    return nextTick;
-}
-
 void
 Pl111::serialize(std::ostream &os)
 {
@@ -586,7 +566,6 @@ Pl111::serialize(std::ostream &os)
     uint8_t clcdCrsrMis_serial = clcdCrsrMis;
     SERIALIZE_SCALAR(clcdCrsrMis_serial);
 
-    SERIALIZE_SCALAR(clock);
     SERIALIZE_SCALAR(height);
     SERIALIZE_SCALAR(width);
     SERIALIZE_SCALAR(bytesPerPixel);
@@ -689,7 +668,6 @@ Pl111::unserialize(Checkpoint *cp, const std::string &section)
     UNSERIALIZE_SCALAR(clcdCrsrMis_serial);
     clcdCrsrMis = clcdCrsrMis_serial;
 
-    UNSERIALIZE_SCALAR(clock);
     UNSERIALIZE_SCALAR(height);
     UNSERIALIZE_SCALAR(width);
     UNSERIALIZE_SCALAR(bytesPerPixel);
diff --git a/src/dev/arm/pl111.hh b/src/dev/arm/pl111.hh
index c4fb84efa..599d4fa3e 100644
--- a/src/dev/arm/pl111.hh
+++ b/src/dev/arm/pl111.hh
@@ -228,9 +228,6 @@ class Pl111: public AmbaDmaDevice
     /** Cursor masked interrupt status register - const */
     InterruptReg clcdCrsrMis;
 
-    /** Clock speed */
-    Tick clock;
-
     /** VNC server */
     VncServer *vncserver;
 
@@ -291,10 +288,6 @@ class Pl111: public AmbaDmaDevice
     /** DMA done event */
     void dmaDone();
 
-    /** Next cycle event */
-    Tick nextCycle();
-    Tick nextCycle(Tick beginTick);
-
     /** DMA framebuffer read event */
     EventWrapper<Pl111, &Pl111::readFramebuffer> readEvent;
 
diff --git a/src/dev/arm/timer_cpulocal.cc b/src/dev/arm/timer_cpulocal.cc
index 97d3c5883..097c52186 100644
--- a/src/dev/arm/timer_cpulocal.cc
+++ b/src/dev/arm/timer_cpulocal.cc
@@ -58,7 +58,7 @@ CpuLocalTimer::CpuLocalTimer(Params *p)
         localTimer[i].parent = this;
         localTimer[i].intNumTimer = p->int_num_timer;
         localTimer[i].intNumWatchdog = p->int_num_watchdog;
-        localTimer[i].clock = p->clock;
+        localTimer[i].clock = clock;
         localTimer[i].cpuNum = i;
     }
     pioSize = 0x38;
@@ -339,7 +339,6 @@ CpuLocalTimer::Timer::serialize(std::ostream &os)
     DPRINTF(Checkpoint, "Serializing Arm CpuLocalTimer\n");
     SERIALIZE_SCALAR(intNumTimer);
     SERIALIZE_SCALAR(intNumWatchdog);
-    SERIALIZE_SCALAR(clock);
 
     uint32_t timer_control_serial = timerControl;
     uint32_t watchdog_control_serial = watchdogControl;
@@ -379,7 +378,6 @@ CpuLocalTimer::Timer::unserialize(Checkpoint *cp, const std::string &section)
 
     UNSERIALIZE_SCALAR(intNumTimer);
     UNSERIALIZE_SCALAR(intNumWatchdog);
-    UNSERIALIZE_SCALAR(clock);
 
     uint32_t timer_control_serial;
     UNSERIALIZE_SCALAR(timer_control_serial);