Changeset 440 for soft/giet_vm/giet_kernel/irq_handler.h

Timestamp:

Nov 3, 2014, 11:03:55 AM (10 years ago)

Author:

alain

Message:

Introducing dynamic allocation of peripheral channels (NIC, TTY, CMA, TIM)
Intoducing a kernel function for all system calls: No more direct call
to the peripheral drivers.

File:

• soft/giet_vm/giet_kernel/irq_handler.h (modified) (1 diff)

soft/giet_vm/giet_kernel/irq_handler.h

@@ -36 +36 @@
 };
 
-///////////////////////////////////////////////////////////////////////////////
-// Prototypes of the Interrupt Service Routines (ISRs) supported by the GIET.
-///////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////////
+//    irq_handler functions
+///////////////////////////////////////////////////////////////////////////////////
 
+///////////////////////////////////////////////////////////////////////////////////
+// This function access the ICU or XICU component (Interrupt Controler Unit)
+// to get the interrupt vector entry. There is one ICU or XICU component per
+// cluster, and this component can support up to NB_PROCS_MAX output IRQs.
+// It returns the highest priority active interrupt index (smaller
+// indexes have the highest priority).
+// Any value larger than 31 means "no active interrupt", and no ISR is executed.
+//
+// There is three interrupt vectors per processor (stored in the processor's
+// scheduler) for the three HWI, PTI, and WTI interrupts types.
+// Each interrupt vector entry contains three bits fields:
+// - isr_id     bits[15:0]  : defines the type of ISR to be executed.
+// - channel_id bits[30:16] : defines the channel for multi-channels peripherals.
+// - valid      bit 31      : valid interrupt vector entry
+// If the peripheral is replicated in clusters, the channel_id is 
+// a global index : channel_id = cluster_id * NB_CHANNELS_MAX + loc_id   
+///////////////////////////////////////////////////////////////////////////////////
 extern void _irq_demux();
 
+///////////////////////////////////////////////////////////////////////////////////
+// This default ISR is called  when the interrupt handler is called, 
+// and there is no active IRQ. It simply displays a warning message on TTY[0].
+///////////////////////////////////////////////////////////////////////////////////
 extern void _isr_default();
 
+///////////////////////////////////////////////////////////////////////////////////
+// This ISR can only be executed after a WTI (IPI) to force a context switch
+// on a remote processor. The context switch is only executed if the current task
+// is the IDLE_TASK, or if the value written in the mailbox is non zero.
+///////////////////////////////////////////////////////////////////////////////////
+extern void _isr_wakup( unsigned int irq_type,
+                        unsigned int irq_id,
+                        unsigned int channel );
+
+/////////////////////////////////////////////////////////////////////////////////////
+// This ISR is in charge of context switch, and handles the IRQs generated by
+// the "system" timers. It can be PTI in case of XCU, or it can be HWI generated
+// by an external timer in case of ICU.
+// The ISR acknowledges the IRQ, and calls the _ctx_switch() function.
+/////////////////////////////////////////////////////////////////////////////////////
 extern void _isr_tick( unsigned int irq_type,
                        unsigned int irq_id,
                        unsigned int channel );
-
-extern void _isr_wakup( unsigned int irq_type,
-                        unsigned int irq_id,
-                        unsigned int channel );
 
 #endif