leon, genirq: SMP support for PCI peripherals

The common interrupt layer for GRLIB PCI perihperals is prepared for SMP
support by this patch. The existing locking (interrupt disabling) is
replaced by a new requirement on the user to implement locking before
calling the genirq API. This approach avoids taking more locks than
necessary.

The split up of the locks also introduces that the user must allocate
memory to describe ISR handlers, to avoid calling malloc()/free() while
possessing a spin-lock and interrupts are globally disabled.

1 files changed, 27 insertions, 31 deletions

diff --git a/c/src/lib/libbsp/sparc/shared/irq/genirq.c b/c/src/lib/libbsp/sparc/shared/irq/genirq.c
index ef6272ce41..bba642e701 100644
--- a/c/src/lib/libbsp/sparc/shared/irq/genirq.c
+++ b/c/src/lib/libbsp/sparc/shared/irq/genirq.c
@@ -1,6 +1,6 @@
 /*
  * Generic interrupt helpers mainly for GRLIB PCI peripherals
- * 
+ *
  * COPYRIGHT (c) 2008.
  * Cobham Gaisler AB.
  *
@@ -47,6 +47,7 @@ genirq_t genirq_init(int number_of_irqs)
 		return NULL;
 	memset(priv, 0, size);
 	priv->genirq_max = number_of_irqs - 1;
+
 	return priv;
 }
 
@@ -64,7 +65,7 @@ void genirq_destroy(genirq_t d)
 		while ( isrentry ) {
 			tmp = isrentry;
 			isrentry = isrentry->next;
-			free(tmp);
+			genirq_free_handler(tmp);
 		}
 	}
 
@@ -81,56 +82,53 @@ int genirq_check(genirq_t d, int irq)
 		return 0;
 }
 
-int genirq_register(genirq_t d, int irq, genirq_handler isr, void *arg)
+void *genirq_alloc_handler(genirq_handler isr, void *arg)
+{
+	struct genirq_handler_entry *newentry;
+
+	newentry = malloc(sizeof(struct genirq_handler_entry));
+	if ( newentry ) {
+		/* Initialize ISR entry */
+		newentry->isr     = isr;
+		newentry->arg     = arg;
+		newentry->enabled = 0;
+	}
+	return newentry;
+}
+
+int genirq_register(genirq_t d, int irq, void *handler)
 {
 	struct genirq_priv *priv = d;
 	struct genirq_irq_entry *irqentry;
-	struct genirq_handler_entry *isrentry, *newentry;
-	rtems_interrupt_level level;
-	
-	if ( genirq_check(d, irq) )
-		return -1;
+	struct genirq_handler_entry *isrentry, *newentry = handler;
 
-	newentry = malloc(sizeof(*newentry));
-	if ( !newentry )
+	if ( genirq_check(d, irq) )
 		return -1;
 
-	/* Initialize ISR entry */
-	newentry->isr     = isr;
-	newentry->arg     = arg;
-	newentry->enabled = 0;
-
-	rtems_interrupt_disable(level);
-
 	/* Insert new ISR entry first into table */
 	irqentry = &priv->genirq_table[irq];
 	isrentry = irqentry->head;
 	irqentry->head = newentry;
 	newentry->next = isrentry;
 
-	rtems_interrupt_enable(level);
-
 	if ( isrentry )
 		return 1; /* This is the first handler on this IRQ */
 	return 0;
 }
 
-int genirq_unregister(genirq_t d, int irq, genirq_handler isr, void *arg)
+void *genirq_unregister(genirq_t d, int irq, genirq_handler isr, void *arg)
 {
 	struct genirq_priv *priv = d;
 	struct genirq_irq_entry *irqentry;
 	struct genirq_handler_entry *isrentry, **prev;
-	rtems_interrupt_level level;
-	int ret;
+	void *ret;
 
 	if ( genirq_check(d, irq) )
-		return -1;
+		return NULL;
 
 	/* Remove isr[arg] from ISR list */
 	irqentry = &priv->genirq_table[irq];
-	ret = -1;
-
-	rtems_interrupt_disable(level);
+	ret = NULL;
 
 	prev = &irqentry->head;
 	isrentry = irqentry->head;
@@ -139,19 +137,17 @@ int genirq_unregister(genirq_t d, int irq, genirq_handler isr, void *arg)
 			/* Found ISR, remove it from list */
 			if ( isrentry->enabled ) {
 				/* Can not remove enabled ISRs, disable first */
-				ret = 1;
+				ret = NULL;
 				break;
 			}
 			*prev = isrentry->next;
-			ret = 0;
+			ret = isrentry;
 			break;
 		}
 		prev = &isrentry->next;
 		isrentry = isrentry->next;
 	}
 
-	rtems_interrupt_enable(level);
-
 	return ret;
 }
 
@@ -226,7 +222,7 @@ void genirq_doirq(genirq_t d, int irq)
 
 	irqentry = &priv->genirq_table[irq];
 	irqentry->stats.irq_cnt++;
-	
+
 	enabled = 0;
 
 	isrentry = irqentry->head;