SE/FS: Remove System::platform and Platform::intrFrequency.

In order for a system object to work in SE mode and FS mode, it has to either
always require a platform object even in SE mode, or get rid of the
requirement all together. Making SE mode carry around unnecessary/unused bits
of FS seems less than ideal, so I decided to go with the second option. The
platform pointer in the System class was used for exactly one purpose, a path
for the Alpha Linux system object to get to the real time clock and read its
frequency so that it could short cut the loops_per_jiffy calculation. There
was also a copy and pasted implementation in MIPS, but since it was only there
because it was there in Alpha I still count that as one use.

This change reverses the mechanism that communicates the RTC frequency so that
the Tsunami platform object pushes it up to the AlphaSystem object. This is
slightly less specific than it could be because really only the
AlphaLinuxSystem uses it. Because the intrFrequency function on the Platform
class was no longer necessary (and unimplemented on anything but Alpha) it was
eliminated.

After this change, a platform will need to have a system, but a system won't
have to have a platform.

src/arch/alpha/linux/system.cc

@@ -49,7 +49,6 @@
 #include "cpu/base.hh"
 #include "cpu/thread_context.hh"
 #include "debug/Thread.hh"
-#include "dev/platform.hh"
 #include "kern/linux/events.hh"
 #include "kern/linux/printk.hh"
 #include "mem/physical.hh"
@@ -164,7 +163,7 @@ LinuxAlphaSystem::setDelayLoop(ThreadContext *tc)
     Addr addr = 0;
     if (kernelSymtab->findAddress("loops_per_jiffy", addr)) {
         Tick cpuFreq = tc->getCpuPtr()->frequency();
-        Tick intrFreq = platform->intrFrequency();
+        assert(intrFreq);
         VirtualPort *vp;
 
         vp = tc->getVirtPort();

src/arch/alpha/system.cc

@@ -46,7 +46,7 @@
 using namespace AlphaISA;
 
 AlphaSystem::AlphaSystem(Params *p)
-    : System(p)
+    : System(p), intrFreq(0)
 {
     consoleSymtab = new SymbolTable;
     palSymtab = new SymbolTable;

src/arch/alpha/system.hh

@@ -79,6 +79,8 @@ class AlphaSystem : public System
 #endif
 
   protected:
+    Tick intrFreq;
+
     const Params *params() const { return (const Params *)_params; }
 
     /** Add a function-based event to PALcode. */
@@ -98,6 +100,9 @@ class AlphaSystem : public System
     }
 
     virtual Addr fixFuncEventAddr(Addr addr);
+
+  public:
+    void setIntrFreq(Tick freq) { intrFreq = freq; }
 };
 
 #endif // __ARCH_ALPHA_SYSTEM_HH__

src/arch/mips/linux/system.cc

@@ -153,15 +153,7 @@ LinuxMipsSystem::~LinuxMipsSystem()
 void
 LinuxMipsSystem::setDelayLoop(ThreadContext *tc)
 {
-    Addr addr = 0;
-    if (kernelSymtab->findAddress("loops_per_jiffy", addr)) {
-        Tick cpuFreq = tc->getCpuPtr()->frequency();
-        Tick intrFreq = platform->intrFrequency();
-        VirtualPort *vp;
-
-        vp = tc->getVirtPort();
-        vp->writeHtoG(addr, (uint32_t)((cpuFreq / intrFreq) * 0.9988));
-    }
+    panic("setDelayLoop not implemented.\n");
 }
 
 

src/dev/alpha/backdoor.cc

@@ -50,6 +50,9 @@
 #include "cpu/thread_context.hh"
 #include "debug/AlphaBackdoor.hh"
 #include "dev/alpha/backdoor.hh"
+#include "dev/alpha/tsunami.hh"
+#include "dev/alpha/tsunami_cchip.hh"
+#include "dev/alpha/tsunami_io.hh"
 #include "dev/platform.hh"
 #include "dev/simple_disk.hh"
 #include "dev/terminal.hh"
@@ -99,7 +102,9 @@ AlphaBackdoor::startup()
     alphaAccess->entryPoint = system->getKernelEntry();
     alphaAccess->mem_size = system->physmem->size();
     alphaAccess->cpuClock = cpu->frequency() / 1000000; // In MHz
-    alphaAccess->intrClockFrequency = params()->platform->intrFrequency();
+    Tsunami *tsunami = dynamic_cast<Tsunami *>(params()->platform);
+    assert(tsunami);
+    alphaAccess->intrClockFrequency = tsunami->io->frequency();
 #endif
 }
 

src/dev/alpha/tsunami.cc

@@ -36,6 +36,12 @@
 #include <string>
 #include <vector>
 
+#include "config/full_system.hh"
+
+#if FULL_SYSTEM //XXX AlphaSystem doesn't build in SE mode yet.
+#include "arch/alpha/system.hh"
+#endif
+
 #include "config/the_isa.hh"
 #include "cpu/intr_control.hh"
 #include "dev/alpha/tsunami.hh"
@@ -43,7 +49,6 @@
 #include "dev/alpha/tsunami_io.hh"
 #include "dev/alpha/tsunami_pchip.hh"
 #include "dev/terminal.hh"
-#include "sim/system.hh"
 
 using namespace std;
 //Should this be AlphaISA?
@@ -52,19 +57,18 @@ using namespace TheISA;
 Tsunami::Tsunami(const Params *p)
     : Platform(p), system(p->system)
 {
-#if FULL_SYSTEM //XXX No platform pointer in SE mode.
-    // set the back pointer from the system to myself
-    system->platform = this;
-#endif
-
     for (int i = 0; i < Tsunami::Max_CPUs; i++)
         intr_sum_type[i] = 0;
 }
 
-Tick
-Tsunami::intrFrequency()
+void
+Tsunami::init()
 {
-    return io->frequency();
+#if FULL_SYSTEM //XXX AlphaSystem doesn't build in SE mode yet.
+    AlphaSystem *alphaSystem = dynamic_cast<AlphaSystem *>(system);
+    assert(alphaSystem);
+    alphaSystem->setIntrFreq(io->frequency());
+#endif
 }
 
 void

src/dev/alpha/tsunami.hh

@@ -80,16 +80,12 @@ class Tsunami : public Platform
     int intr_sum_type[Tsunami::Max_CPUs];
     int ipi_pending[Tsunami::Max_CPUs];
 
+    void init();
+
   public:
     typedef TsunamiParams Params;
     Tsunami(const Params *p);
 
-    /**
-     * Return the interrupting frequency to AlphaAccess
-     * @return frequency of RTC interrupts
-     */
-    virtual Tick intrFrequency();
-
     /**
      * Cause the cpu to post a serial interrupt to the CPU.
      */

src/dev/arm/realview.cc

@@ -60,19 +60,7 @@ using namespace TheISA;
 
 RealView::RealView(const Params *p)
     : Platform(p), system(p->system)
-{
-#if FULL_SYSTEM //XXX No platform pointer on the system object in SE mode.
-    // set the back pointer from the system to myself
-    system->platform = this;
-#endif
-}
-
-Tick
-RealView::intrFrequency()
-{
-    panic("Need implementation\n");
-    M5_DUMMY_RETURN
-}
+{}
 
 void
 RealView::postConsoleInt()

src/dev/arm/realview.hh

@@ -81,12 +81,6 @@ class RealView : public Platform
     /** Give platform a pointer to interrupt controller */
     void setGic(Gic *_gic) { gic = _gic; }
 
-    /**
-     * Return the interrupting frequency to AlphaAccess
-     * @return frequency of RTC interrupts
-     */
-    virtual Tick intrFrequency();
-
     /**
      * Cause the cpu to post a serial interrupt to the CPU.
      */

src/dev/mips/malta.cc

@@ -54,21 +54,10 @@ using namespace TheISA;
 Malta::Malta(const Params *p)
     : Platform(p), system(p->system)
 {
-#if FULL_SYSTEM //XXX No platform pointer on the system object in SE mode.
-    // set the back pointer from the system to myself
-    system->platform = this;
-#endif
-
     for (int i = 0; i < Malta::Max_CPUs; i++)
         intr_sum_type[i] = 0;
 }
 
-Tick
-Malta::intrFrequency()
-{
-    return io->frequency();
-}
-
 void
 Malta::postConsoleInt()
 {

src/dev/mips/malta.hh

@@ -91,12 +91,6 @@ class Malta : public Platform
     typedef MaltaParams Params;
     Malta(const Params *p);
 
-    /**
-     * Return the interrupting frequency to MipsAccess
-     * @return frequency of RTC interrupts
-     */
-    virtual Tick intrFrequency();
-
     /**
      * Cause the cpu to post a serial interrupt to the CPU.
      */

src/dev/platform.hh

@@ -64,7 +64,6 @@ class Platform : public SimObject
     virtual ~Platform();
     virtual void postConsoleInt() = 0;
     virtual void clearConsoleInt() = 0;
-    virtual Tick intrFrequency() = 0;
     virtual void postPciInt(int line);
     virtual void clearPciInt(int line);
     virtual Addr pciToDma(Addr pciAddr) const;

src/dev/sparc/t1000.cc

@@ -48,19 +48,7 @@ using namespace TheISA;
 
 T1000::T1000(const Params *p)
     : Platform(p), system(p->system)
-{
-#if FULL_SYSTEM //XXX No platform pointer on system objects in SE mode.
-    // set the back pointer from the system to myself
-    system->platform = this;
-#endif
-}
-
-Tick
-T1000::intrFrequency()
-{
-    panic("Need implementation\n");
-    M5_DUMMY_RETURN
-}
+{}
 
 void
 T1000::postConsoleInt()

src/dev/sparc/t1000.hh

@@ -59,12 +59,6 @@ class T1000 : public Platform
      */
     T1000(const Params *p);
 
-    /**
-     * Return the interrupting frequency to AlphaAccess
-     * @return frequency of RTC interrupts
-     */
-    virtual Tick intrFrequency();
-
     /**
      * Cause the cpu to post a serial interrupt to the CPU.
      */

src/dev/x86/pc.cc

@@ -55,10 +55,6 @@ Pc::Pc(const Params *p)
     : Platform(p), system(p->system)
 {
     southBridge = NULL;
-    // set the back pointer from the system to myself
-#if FULL_SYSTEM //XXX No platform pointer in SE mode.
-    system->platform = this;
-#endif
 }
 
 void
@@ -119,13 +115,6 @@ Pc::init()
     southBridge->pic2->maskAll();
 }
 
-Tick
-Pc::intrFrequency()
-{
-    panic("Need implementation for intrFrequency\n");
-    M5_DUMMY_RETURN
-}
-
 void
 Pc::postConsoleInt()
 {

src/dev/x86/pc.hh

@@ -61,12 +61,6 @@ class Pc : public Platform
 
     Pc(const Params *p);
 
-    /**
-     * Return the interrupting frequency to AlphaAccess
-     * @return frequency of RTC interrupts
-     */
-    virtual Tick intrFrequency();
-
     /**
      * Cause the cpu to post a serial interrupt to the CPU.
      */

src/sim/system.hh

@@ -114,7 +114,6 @@ class System : public SimObject
     bool isMemory(const Addr addr) const;
 
 #if FULL_SYSTEM
-    Platform *platform;
     uint64_t init_param;
 
     /** Port to physical memory used for writing object files into ram at