[SPARC64]: Send all device interrupts via one PIL.

This is the first in a series of cleanups that will hopefully
allow a seamless attempt at using the generic IRQ handling
infrastructure in the Linux kernel.

Define PIL_DEVICE_IRQ and vector all device interrupts through
there.

Get rid of the ugly pil0_dummy_{bucket,desc}, instead vector
the timer interrupt directly to a specific handler since the
timer interrupt is the only event that will be signaled on
PIL 14.

The irq_worklist is now in the per-cpu trap_block[].

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 69 insertions, 94 deletions

diff --git a/arch/sparc64/kernel/irq.c b/arch/sparc64/kernel/irq.c
index 11e645c9ec5..0fb1738a4f3 100644
--- a/arch/sparc64/kernel/irq.c
+++ b/arch/sparc64/kernel/irq.c
@@ -68,11 +68,7 @@ struct ino_bucket ivector_table[NUM_IVECS] __attribute__ ((aligned (SMP_CACHE_BY
  * access to this structure takes a TLB miss it could cause
  * the 5-level sparc v9 trap stack to overflow.
  */
-struct irq_work_struct {
-	unsigned int	irq_worklists[16];
-};
-struct irq_work_struct __irq_work[NR_CPUS];
-#define irq_work(__cpu, __pil)	&(__irq_work[(__cpu)].irq_worklists[(__pil)])
+#define irq_work(__cpu)	&(trap_block[(__cpu)].irq_worklist)
 
 static struct irqaction *irq_action[NR_IRQS+1];
 
@@ -91,10 +87,8 @@ static void register_irq_proc (unsigned int irq);
  */
 #define put_ino_in_irqaction(action, irq) \
 	action->flags &= 0xffffffffffffUL; \
-	if (__bucket(irq) == &pil0_dummy_bucket) \
-		action->flags |= 0xdeadUL << 48;  \
-	else \
-		action->flags |= __irq_ino(irq) << 48;
+	action->flags |= __irq_ino(irq) << 48;
+
 #define get_ino_in_irqaction(action)	(action->flags >> 48)
 
 #define put_smpaff_in_irqaction(action, smpaff)	(action)->mask = (smpaff)
@@ -251,15 +245,6 @@ void disable_irq(unsigned int irq)
 	}
 }
 
-/* The timer is the one "weird" interrupt which is generated by
- * the CPU %tick register and not by some normal vectored interrupt
- * source.  To handle this special case, we use this dummy INO bucket.
- */
-static struct irq_desc pil0_dummy_desc;
-static struct ino_bucket pil0_dummy_bucket = {
-	.irq_info	=	&pil0_dummy_desc,
-};
-
 static void build_irq_error(const char *msg, unsigned int ino, int pil, int inofixup,
 			    unsigned long iclr, unsigned long imap,
 			    struct ino_bucket *bucket)
@@ -276,15 +261,7 @@ unsigned int build_irq(int pil, int inofixup, unsigned long iclr, unsigned long
 	struct ino_bucket *bucket;
 	int ino;
 
-	if (pil == 0) {
-		if (iclr != 0UL || imap != 0UL) {
-			prom_printf("Invalid dummy bucket for PIL0 (%lx:%lx)\n",
-				    iclr, imap);
-			prom_halt();
-		}
-		return __irq(&pil0_dummy_bucket);
-	}
-
+	BUG_ON(pil == 0);
 	BUG_ON(tlb_type == hypervisor);
 
 	/* RULE: Both must be specified in all other cases. */
@@ -371,7 +348,7 @@ static void atomic_bucket_insert(struct ino_bucket *bucket)
 	__asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
 	__asm__ __volatile__("wrpr %0, %1, %%pstate"
 			     : : "r" (pstate), "i" (PSTATE_IE));
-	ent = irq_work(smp_processor_id(), bucket->pil);
+	ent = irq_work(smp_processor_id());
 	bucket->irq_chain = *ent;
 	*ent = __irq(bucket);
 	__asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate));
@@ -437,7 +414,7 @@ int request_irq(unsigned int irq, irqreturn_t (*handler)(int, void *, struct pt_
 	if (unlikely(!bucket->irq_info))
 		return -ENODEV;
 
-	if ((bucket != &pil0_dummy_bucket) && (irqflags & SA_SAMPLE_RANDOM)) {
+	if (irqflags & SA_SAMPLE_RANDOM) {
 		/*
 	 	 * This function might sleep, we want to call it first,
 	 	 * outside of the atomic block. In SA_STATIC_ALLOC case,
@@ -465,12 +442,9 @@ int request_irq(unsigned int irq, irqreturn_t (*handler)(int, void *, struct pt_
 	}
 
 	bucket->flags |= IBF_ACTIVE;
-	pending = 0;
-	if (bucket != &pil0_dummy_bucket) {
-		pending = bucket->pending;
-		if (pending)
-			bucket->pending = 0;
-	}
+	pending = bucket->pending;
+	if (pending)
+		bucket->pending = 0;
 
 	action->handler = handler;
 	action->flags = irqflags;
@@ -487,13 +461,12 @@ int request_irq(unsigned int irq, irqreturn_t (*handler)(int, void *, struct pt_
 	/* We ate the IVEC already, this makes sure it does not get lost. */
 	if (pending) {
 		atomic_bucket_insert(bucket);
-		set_softint(1 << bucket->pil);
+		set_softint(1 << PIL_DEVICE_IRQ);
 	}
 
 	spin_unlock_irqrestore(&irq_action_lock, flags);
 
-	if (bucket != &pil0_dummy_bucket)
-		register_irq_proc(__irq_ino(irq));
+	register_irq_proc(__irq_ino(irq));
 
 #ifdef CONFIG_SMP
 	distribute_irqs();
@@ -533,7 +506,9 @@ void free_irq(unsigned int irq, void *dev_id)
 {
 	struct irqaction *action;
 	struct ino_bucket *bucket;
+	struct irq_desc *desc;
 	unsigned long flags;
+	int ent, i;
 
 	spin_lock_irqsave(&irq_action_lock, flags);
 
@@ -549,42 +524,39 @@ void free_irq(unsigned int irq, void *dev_id)
 	spin_lock_irqsave(&irq_action_lock, flags);
 
 	bucket = __bucket(irq);
-	if (bucket != &pil0_dummy_bucket) {
-		struct irq_desc *desc = bucket->irq_info;
-		int ent, i;
+	desc = bucket->irq_info;
 
-		for (i = 0; i < MAX_IRQ_DESC_ACTION; i++) {
-			struct irqaction *p = &desc->action[i];
+	for (i = 0; i < MAX_IRQ_DESC_ACTION; i++) {
+		struct irqaction *p = &desc->action[i];
 
-			if (p == action) {
-				desc->action_active_mask &= ~(1 << i);
-				break;
-			}
+		if (p == action) {
+			desc->action_active_mask &= ~(1 << i);
+			break;
 		}
+	}
 
-		if (!desc->action_active_mask) {
-			unsigned long imap = bucket->imap;
-
-			/* This unique interrupt source is now inactive. */
-			bucket->flags &= ~IBF_ACTIVE;
+	if (!desc->action_active_mask) {
+		unsigned long imap = bucket->imap;
 
-			/* See if any other buckets share this bucket's IMAP
-			 * and are still active.
-			 */
-			for (ent = 0; ent < NUM_IVECS; ent++) {
-				struct ino_bucket *bp = &ivector_table[ent];
-				if (bp != bucket	&&
-				    bp->imap == imap	&&
-				    (bp->flags & IBF_ACTIVE) != 0)
-					break;
-			}
+		/* This unique interrupt source is now inactive. */
+		bucket->flags &= ~IBF_ACTIVE;
 
-			/* Only disable when no other sub-irq levels of
-			 * the same IMAP are active.
-			 */
-			if (ent == NUM_IVECS)
-				disable_irq(irq);
+		/* See if any other buckets share this bucket's IMAP
+		 * and are still active.
+		 */
+		for (ent = 0; ent < NUM_IVECS; ent++) {
+			struct ino_bucket *bp = &ivector_table[ent];
+			if (bp != bucket	&&
+			    bp->imap == imap	&&
+			    (bp->flags & IBF_ACTIVE) != 0)
+				break;
 		}
+
+		/* Only disable when no other sub-irq levels of
+		 * the same IMAP are active.
+		 */
+		if (ent == NUM_IVECS)
+			disable_irq(irq);
 	}
 
 	spin_unlock_irqrestore(&irq_action_lock, flags);
@@ -625,7 +597,7 @@ void synchronize_irq(unsigned int irq)
 }
 #endif /* CONFIG_SMP */
 
-static void process_bucket(int irq, struct ino_bucket *bp, struct pt_regs *regs)
+static void process_bucket(struct ino_bucket *bp, struct pt_regs *regs)
 {
 	struct irq_desc *desc = bp->irq_info;
 	unsigned char flags = bp->flags;
@@ -676,51 +648,54 @@ static void process_bucket(int irq, struct ino_bucket *bp, struct pt_regs *regs)
 
 		/* Test and add entropy */
 		if (random & SA_SAMPLE_RANDOM)
-			add_interrupt_randomness(irq);
+			add_interrupt_randomness(bp->pil);
 	}
 out:
 	bp->flags &= ~IBF_INPROGRESS;
 }
 
+#ifndef CONFIG_SMP
+extern irqreturn_t timer_interrupt(int, void *, struct pt_regs *);
+
+void timer_irq(int irq, struct pt_regs *regs)
+{
+	unsigned long clr_mask = 1 << irq;
+	unsigned long tick_mask = tick_ops->softint_mask;
+
+	if (get_softint() & tick_mask) {
+		irq = 0;
+		clr_mask = tick_mask;
+	}
+	clear_softint(clr_mask);
+
+	irq_enter();
+	kstat_this_cpu.irqs[irq]++;
+	timer_interrupt(irq, NULL, regs);
+	irq_exit();
+}
+#endif
+
 void handler_irq(int irq, struct pt_regs *regs)
 {
 	struct ino_bucket *bp;
 	int cpu = smp_processor_id();
 
-#ifndef CONFIG_SMP
-	/*
-	 * Check for TICK_INT on level 14 softint.
+	/* XXX at this point we should be able to assert that
+	 * XXX irq is PIL_DEVICE_IRQ...
 	 */
-	{
-		unsigned long clr_mask = 1 << irq;
-		unsigned long tick_mask = tick_ops->softint_mask;
-
-		if ((irq == 14) && (get_softint() & tick_mask)) {
-			irq = 0;
-			clr_mask = tick_mask;
-		}
-		clear_softint(clr_mask);
-	}
-#else
 	clear_softint(1 << irq);
-#endif
 
 	irq_enter();
-	kstat_this_cpu.irqs[irq]++;
 
 	/* Sliiiick... */
-#ifndef CONFIG_SMP
-	bp = ((irq != 0) ?
-	      __bucket(xchg32(irq_work(cpu, irq), 0)) :
-	      &pil0_dummy_bucket);
-#else
-	bp = __bucket(xchg32(irq_work(cpu, irq), 0));
-#endif
+	bp = __bucket(xchg32(irq_work(cpu), 0));
 	while (bp) {
 		struct ino_bucket *nbp = __bucket(bp->irq_chain);
 
+		kstat_this_cpu.irqs[bp->pil]++;
+
 		bp->irq_chain = 0;
-		process_bucket(irq, bp, regs);
+		process_bucket(bp, regs);
 		bp = nbp;
 	}
 	irq_exit();
@@ -929,7 +904,7 @@ void init_irqwork_curcpu(void)
 {
 	int cpu = hard_smp_processor_id();
 
-	memset(__irq_work + cpu, 0, sizeof(struct irq_work_struct));
+	trap_block[cpu].irq_worklist = 0;
 }
 
 static void __cpuinit register_one_mondo(unsigned long paddr, unsigned long type)