dev, arm: Implement the NoMali reset callback

Add a callback handler for the NoMali reset callback. This callback is
called whenever the GPU is reset using the register interface or the
NoMali API. The callback can be used to override ID registers using
the raw register API.

src/dev/arm/gpu_nomali.cc

@@ -92,6 +92,13 @@ NoMaliGpu::NoMaliGpu(const NoMaliGpuParams *p)
     cbk_int.func.interrupt = NoMaliGpu::_interrupt;
     setCallback(cbk_int);
 
+    /* Setup a reset callback */
+    nomali_callback_t cbk_rst;
+    cbk_rst.type = NOMALI_CALLBACK_RESET;
+    cbk_rst.usr = (void *)this;
+    cbk_rst.func.reset = NoMaliGpu::_reset;
+    setCallback(cbk_rst);
+
     panicOnErr(
         nomali_get_info(nomali, &nomaliInfo),
         "Failed to get NoMali information struct");
@@ -102,6 +109,18 @@ NoMaliGpu::~NoMaliGpu()
     nomali_destroy(nomali);
 }
 
+
+void
+NoMaliGpu::init()
+{
+    PioDevice::init();
+
+    /* Reset the GPU here since the reset callback won't have been
+     * installed when the GPU was reset at instantiation time.
+     */
+    reset();
+}
+
 void
 NoMaliGpu::serialize(CheckpointOut &cp) const
 {
@@ -267,6 +286,12 @@ NoMaliGpu::onInterrupt(nomali_int_t intno, bool set)
         platform->gic->clearInt(it_int->second);
 }
 
+void
+NoMaliGpu::onReset()
+{
+    DPRINTF(NoMali, "Reset\n");
+}
+
 void
 NoMaliGpu::setCallback(const nomali_callback_t &callback)
 {
@@ -287,6 +312,14 @@ NoMaliGpu::_interrupt(nomali_handle_t h, void *usr,
     _this->onInterrupt(intno, !!set);
 }
 
+void
+NoMaliGpu::_reset(nomali_handle_t h, void *usr)
+{
+    NoMaliGpu *_this(static_cast<NoMaliGpu *>(usr));
+
+    _this->onReset();
+}
+
 NoMaliGpu *
 NoMaliGpuParams::create()
 {

src/dev/arm/gpu_nomali.hh

@@ -54,6 +54,8 @@ class NoMaliGpu : public PioDevice
     NoMaliGpu(const NoMaliGpuParams *p);
     virtual ~NoMaliGpu();
 
+    void init() override;
+
   public: /* Checkpointing */
     void serialize(CheckpointOut &cp) const override;
     void unserialize(CheckpointIn &cp) override;
@@ -126,6 +128,14 @@ class NoMaliGpu : public PioDevice
      */
     virtual void onInterrupt(nomali_int_t intno, bool set);
 
+    /**
+     * Reset callback from the NoMali library
+     *
+     * This method is called whenever the GPU is reset through the
+     * register interface or the API (reset() or nomali_reset()).
+     */
+    virtual void onReset();
+
     /** @} */
 
   private: /* Callback helpers */
@@ -145,6 +155,18 @@ class NoMaliGpu : public PioDevice
      */
     static void _interrupt(nomali_handle_t h, void *usr,
                            nomali_int_t intno, int set);
+
+    /**
+     * Reset callback from the NoMali library.
+     *
+     * This method calls onReset() on the NoMaliGpu owning this
+     * device.
+     *
+     * @param h NoMali library handle.
+     * @param usr Pointer to an instance of the NoMaliGpu
+     */
+    static void _reset(nomali_handle_t h, void *usr);
+
   protected:
     /** Device base address */
     const Addr pioAddr;