sim: Thermal support for Linux

This patch enables Linux to read the temperature using hwmon infrastructure.
In order to use this in your gem5 you need to compile the kernel using the
following configs:

CONFIG_HWMON=y
CONFIG_SENSORS_VEXPRESS=y

And a proper dts file (containing an entry such as):

dcc {
 compatible = "arm,vexpress,config-bus";
 arm,vexpress,config-bridge = <&v2m_sysreg>;

  temp@0 {
   compatible = "arm,vexpress-temp";
   arm,vexpress-sysreg,func = <4 0>;
   label = "DCC";
  };
};

diff --git a/src/dev/arm/RealView.py b/src/dev/arm/RealView.py
index 9d4dc6aaff51129ca5c1ead75f6ab5e12d8bdec2..17b3eb51dca742b1bb3102b1d754fa0799fc2c71 100644 (file)
--- a/src/dev/arm/RealView.py
+++ b/src/dev/arm/RealView.py
@@ -129,6 +129,22 @@ class RealViewOsc(ClockDomain):
 
     freq = Param.Clock("Default frequency")
 
+class RealViewTemperatureSensor(SimObject):
+    type = 'RealViewTemperatureSensor'
+    cxx_header = "dev/arm/rv_ctrl.hh"
+
+    parent = Param.RealViewCtrl(Parent.any, "RealView controller")
+
+    system = Param.System(Parent.any, "system")
+
+    # See ARM DUI 0447J (ARM Motherboard Express uATX -- V2M-P1) and
+    # the individual core/logic tile reference manuals for details
+    # about the site/position/dcc/device allocation.
+    site = Param.UInt8("Board Site")
+    position = Param.UInt8("Position in device stack")
+    dcc = Param.UInt8("Daughterboard Configuration Controller")
+    device = Param.UInt8("Device ID")
+
 class VExpressMCC(SubSystem):
     """ARM V2M-P1 Motherboard Configuration Controller
 
@@ -140,11 +156,17 @@ Express (V2M-P1) motherboard. See ARM DUI 0447J for details.
     class Osc(RealViewOsc):
         site, position, dcc = (0, 0, 0)
 
+    class Temperature(RealViewTemperatureSensor):
+        site, position, dcc = (0, 0, 0)
+
     osc_mcc = Osc(device=0, freq="50MHz")
     osc_clcd = Osc(device=1, freq="23.75MHz")
     osc_peripheral = Osc(device=2, freq="24MHz")
     osc_system_bus = Osc(device=4, freq="24MHz")
 
+    # See Table 4.19 in ARM DUI 0447J (Motherboard Express uATX TRM).
+    temp_crtl = Temperature(device=0)
+
 class CoreTile2A15DCC(SubSystem):
     """ARM CoreTile Express A15x2 Daughterboard Configuration Controller
 

diff --git a/src/dev/arm/rv_ctrl.cc b/src/dev/arm/rv_ctrl.cc
index 507def0c14a7c957f489bb5394b25cbc233fb93e..f89f23b598492e1bde908df6b9a5a080f9dac3dc 100644 (file)
--- a/src/dev/arm/rv_ctrl.cc
+++ b/src/dev/arm/rv_ctrl.cc
@@ -37,11 +37,14 @@
  * Authors: Ali Saidi
  */
 
+#include "dev/arm/rv_ctrl.hh"
+
 #include "base/trace.hh"
 #include "debug/RVCTRL.hh"
-#include "dev/arm/rv_ctrl.hh"
 #include "mem/packet.hh"
 #include "mem/packet_access.hh"
+#include "sim/power/thermal_model.hh"
+#include "sim/system.hh"
 #include "sim/voltage_domain.hh"
 
 RealViewCtrl::RealViewCtrl(Params *p)
@@ -293,7 +296,21 @@ RealViewOsc::write(uint32_t freq)
     clockPeriod(SimClock::Float::s / freq);
 }
 
+uint32_t
+RealViewTemperatureSensor::read() const
+{
+    // Temperature reported in uC
+    ThermalModel * tm = system->getThermalModel();
+    if (tm) {
+        double t = tm->getTemp();
+        if (t < 0)
+            warn("Temperature below zero!\n");
+        return fmax(0, t) * 1000000;
+    }
 
+    // Report a dummy 25 degrees temperature
+    return 25000000;
+}
 
 RealViewCtrl *
 RealViewCtrlParams::create()
@@ -306,3 +323,9 @@ RealViewOscParams::create()
 {
     return new RealViewOsc(this);
 }
+
+RealViewTemperatureSensor *
+RealViewTemperatureSensorParams::create()
+{
+    return new RealViewTemperatureSensor(this);
+}

diff --git a/src/dev/arm/rv_ctrl.hh b/src/dev/arm/rv_ctrl.hh
index 1a55025a8e63f8d0d45a143900b1e37a7f76cee0..b325c4b16ee7d8889beb674b4508cf755b73830c 100644 (file)
--- a/src/dev/arm/rv_ctrl.hh
+++ b/src/dev/arm/rv_ctrl.hh
@@ -44,6 +44,7 @@
 #include "dev/io_device.hh"
 #include "params/RealViewCtrl.hh"
 #include "params/RealViewOsc.hh"
+#include "params/RealViewTemperatureSensor.hh"
 
 /** @file
  * This implements the simple real view registers on a PBXA9
@@ -219,5 +220,32 @@ class RealViewOsc
     void clockPeriod(Tick clock_period);
 };
 
+/**
+ * This device implements the temperature sensor used in the
+ * RealView/Versatile Express platform.
+ *
+ * See ARM DUI 0447J (ARM  Motherboard Express uATX -- V2M-P1).
+ */
+class RealViewTemperatureSensor
+    : public SimObject, RealViewCtrl::Device
+{
+  public:
+    RealViewTemperatureSensor(RealViewTemperatureSensorParams *p)
+    : SimObject(p),
+      RealViewCtrl::Device(*p->parent, RealViewCtrl::FUNC_TEMP,
+                           p->site, p->position, p->dcc, p->device),
+      system(p->system)
+    {}
+    virtual ~RealViewTemperatureSensor() {};
+
+  public: // RealViewCtrl::Device interface
+    uint32_t read() const override;
+    void write(uint32_t temp) override {}
+
+  protected:
+    /** The system this RV device belongs to */
+    System * system;
+};
+
 
 #endif // __DEV_ARM_RV_HH__