[SPARC]: Try to start getting SMP back into shape.

Todo items:
 - IRQ_INPROGRESS flag - use sparc64 irq buckets, or generic irq_desc?
 - sun4d
 - re-indent large chunks of sun4m_smp.c
 - some places assume sequential cpu numbering (i.e. 0,1 instead of 0,2)

Last I checked (with 2.6.14), random programs segfault with dual
HyperSPARC.  And with SuperSPARC II's, it seems stable but will
eventually die from a write lock error (wrong lock owner or something).

I haven't tried the HyperSPARC + highmem combination recently, so that
may still be a problem.

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

1 files changed, 34 insertions, 32 deletions

diff --git a/arch/sparc/kernel/irq.c b/arch/sparc/kernel/irq.c
index 4c60a6ef54a9..aac8af5aae51 100644
--- a/arch/sparc/kernel/irq.c
+++ b/arch/sparc/kernel/irq.c
@@ -154,9 +154,11 @@ void (*sparc_init_timers)(irqreturn_t (*)(int, void *,struct pt_regs *)) =
 struct irqaction static_irqaction[MAX_STATIC_ALLOC];
 int static_irq_count;
 
-struct irqaction *irq_action[NR_IRQS] = {
-        [0 ... (NR_IRQS-1)] = NULL
-};
+struct {
+        struct irqaction *action;
+        int flags;
+} sparc_irq[NR_IRQS];
+#define SPARC_IRQ_INPROGRESS 1
 
 /* Used to protect the IRQ action lists */
 DEFINE_SPINLOCK(irq_action_lock);
@@ -177,7 +179,7 @@ int show_interrupts(struct seq_file *p, void *v)
         }
         spin_lock_irqsave(&irq_action_lock, flags);
         if (i < NR_IRQS) {
-                action = *(i + irq_action);
+                action = sparc_irq[i].action;
                 if (!action) 
                         goto out_unlock;
                 seq_printf(p, "%3d: ", i);
@@ -186,7 +188,7 @@ int show_interrupts(struct seq_file *p, void *v)
 #else
                 for_each_online_cpu(j) {
                         seq_printf(p, "%10u ",
-                                    kstat_cpu(cpu_logical_map(j)).irqs[i]);
+                                    kstat_cpu(j).irqs[i]);
                 }
 #endif
                 seq_printf(p, " %c %s",
@@ -207,7 +209,7 @@ out_unlock:
 void free_irq(unsigned int irq, void *dev_id)
 {
         struct irqaction * action;
-        struct irqaction * tmp = NULL;
+        struct irqaction **actionp;
         unsigned long flags;
         unsigned int cpu_irq;
         
@@ -225,7 +227,8 @@ void free_irq(unsigned int irq, void *dev_id)
 
         spin_lock_irqsave(&irq_action_lock, flags);
 
-        action = *(cpu_irq + irq_action);
+        actionp = &sparc_irq[cpu_irq].action;
+        action = *actionp;
 
         if (!action->handler) {
                 printk("Trying to free free IRQ%d\n",irq);
@@ -235,7 +238,7 @@ void free_irq(unsigned int irq, void *dev_id)
                 for (; action; action = action->next) {
                         if (action->dev_id == dev_id)
                                 break;
-                        tmp = action;
+                        actionp = &action->next;
                 }
                 if (!action) {
                         printk("Trying to free free shared IRQ%d\n",irq);
@@ -254,11 +257,8 @@ void free_irq(unsigned int irq, void *dev_id)
                        irq, action->name);
                 goto out_unlock;
         }
-        
-        if (action && tmp)
-                tmp->next = action->next;
-        else
-                *(cpu_irq + irq_action) = action->next;
+
+        *actionp = action->next;
 
         spin_unlock_irqrestore(&irq_action_lock, flags);
 
@@ -268,7 +268,7 @@ void free_irq(unsigned int irq, void *dev_id)
 
         kfree(action);
 
-        if (!(*(cpu_irq + irq_action)))
+        if (!sparc_irq[cpu_irq].action)
                 disable_irq(irq);
 
 out_unlock:
@@ -287,8 +287,11 @@ EXPORT_SYMBOL(free_irq);
 #ifdef CONFIG_SMP
 void synchronize_irq(unsigned int irq)
 {
-        printk("synchronize_irq says: implement me!\n");
-        BUG();
+        unsigned int cpu_irq;
+
+        cpu_irq = irq & (NR_IRQS - 1);
+        while (sparc_irq[cpu_irq].flags & SPARC_IRQ_INPROGRESS)
+                cpu_relax();
 }
 #endif /* SMP */
 
@@ -299,7 +302,7 @@ void unexpected_irq(int irq, void *dev_id, struct pt_regs * regs)
         unsigned int cpu_irq;
         
         cpu_irq = irq & (NR_IRQS - 1);
-        action = *(cpu_irq + irq_action);
+        action = sparc_irq[cpu_irq].action;
 
         printk("IO device interrupt, irq = %d\n", irq);
         printk("PC = %08lx NPC = %08lx FP=%08lx\n", regs->pc, 
@@ -330,7 +333,8 @@ void handler_irq(int irq, struct pt_regs * regs)
         if(irq < 10)
                 smp4m_irq_rotate(cpu);
 #endif
-        action = *(irq + irq_action);
+        action = sparc_irq[irq].action;
+        sparc_irq[irq].flags |= SPARC_IRQ_INPROGRESS;
         kstat_cpu(cpu).irqs[irq]++;
         do {
                 if (!action || !action->handler)
@@ -338,6 +342,7 @@ void handler_irq(int irq, struct pt_regs * regs)
                 action->handler(irq, action->dev_id, regs);
                 action = action->next;
         } while (action);
+        sparc_irq[irq].flags &= ~SPARC_IRQ_INPROGRESS;
         enable_pil_irq(irq);
         irq_exit();
 }
@@ -389,7 +394,7 @@ int request_fast_irq(unsigned int irq,
 
         spin_lock_irqsave(&irq_action_lock, flags);
 
-        action = *(cpu_irq + irq_action);
+        action = sparc_irq[cpu_irq].action;
         if(action) {
                 if(action->flags & SA_SHIRQ)
                         panic("Trying to register fast irq when already shared.\n");
@@ -452,7 +457,7 @@ int request_fast_irq(unsigned int irq,
         action->dev_id = NULL;
         action->next = NULL;
 
-        *(cpu_irq + irq_action) = action;
+        sparc_irq[cpu_irq].action = action;
 
         enable_irq(irq);
 
@@ -467,7 +472,7 @@ int request_irq(unsigned int irq,
                 irqreturn_t (*handler)(int, void *, struct pt_regs *),
                 unsigned long irqflags, const char * devname, void *dev_id)
 {
-        struct irqaction * action, *tmp = NULL;
+        struct irqaction * action, **actionp;
         unsigned long flags;
         unsigned int cpu_irq;
         int ret;
@@ -490,20 +495,20 @@ int request_irq(unsigned int irq,
             
         spin_lock_irqsave(&irq_action_lock, flags);
 
-        action = *(cpu_irq + irq_action);
+        actionp = &sparc_irq[cpu_irq].action;
+        action = *actionp;
         if (action) {
-                if ((action->flags & SA_SHIRQ) && (irqflags & SA_SHIRQ)) {
-                        for (tmp = action; tmp->next; tmp = tmp->next);
-                } else {
+                if (!(action->flags & SA_SHIRQ) || !(irqflags & SA_SHIRQ)) {
                         ret = -EBUSY;
                         goto out_unlock;
                 }
-                if ((action->flags & SA_INTERRUPT) ^ (irqflags & SA_INTERRUPT)) {
+                if ((action->flags & SA_INTERRUPT) != (irqflags & SA_INTERRUPT)) {
                         printk("Attempt to mix fast and slow interrupts on IRQ%d denied\n", irq);
                         ret = -EBUSY;
                         goto out_unlock;
-                }   
-                action = NULL;          /* Or else! */
+                }
+                for ( ; action; action = *actionp)
+                        actionp = &action->next;
         }
 
         /* If this is flagged as statically allocated then we use our
@@ -532,10 +537,7 @@ int request_irq(unsigned int irq,
         action->next = NULL;
         action->dev_id = dev_id;
 
-        if (tmp)
-                tmp->next = action;
-        else
-                *(cpu_irq + irq_action) = action;
+        *actionp = action;
 
         enable_irq(irq);