[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>

arch/sparc/Kconfig

@@ -23,7 +23,6 @@ menu "General machine setup"
 
 config SMP
 	bool "Symmetric multi-processing support (does not work on sun4/sun4c)"
-	depends on BROKEN
 	---help---
 	  This enables support for systems with more than one CPU. If you have
 	  a system with only one CPU, say N. If you have a system with more

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 @@ int show_interrupts(struct seq_file *p, void *v)
 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, 
@@ -330,14 +333,16 @@ 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)
 			unexpected_irq(irq, NULL, 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);
 

arch/sparc/kernel/smp.c

@@ -45,6 +45,7 @@ volatile int __cpu_logical_map[NR_CPUS];
 
 cpumask_t cpu_online_map = CPU_MASK_NONE;
 cpumask_t phys_cpu_present_map = CPU_MASK_NONE;
+cpumask_t smp_commenced_mask = CPU_MASK_NONE;
 
 /* The only guaranteed locking primitive available on all Sparc
  * processors is 'ldstub [%reg + immediate], %dest_reg' which atomically
@@ -57,11 +58,6 @@ cpumask_t phys_cpu_present_map = CPU_MASK_NONE;
 /* Used to make bitops atomic */
 unsigned char bitops_spinlock = 0;
 
-volatile unsigned long ipi_count;
-
-volatile int smp_process_available=0;
-volatile int smp_commenced = 0;
-
 void __init smp_store_cpu_info(int id)
 {
 	int cpu_node;
@@ -79,6 +75,22 @@ void __init smp_store_cpu_info(int id)
 
 void __init smp_cpus_done(unsigned int max_cpus)
 {
+	extern void smp4m_smp_done(void);
+	unsigned long bogosum = 0;
+	int cpu, num;
+
+	for (cpu = 0, num = 0; cpu < NR_CPUS; cpu++)
+		if (cpu_online(cpu)) {
+			num++;
+			bogosum += cpu_data(cpu).udelay_val;
+		}
+
+	printk("Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
+		num, bogosum/(500000/HZ),
+		(bogosum/(5000/HZ))%100);
+
+	BUG_ON(sparc_cpu_model != sun4m);
+	smp4m_smp_done();
 }
 
 void cpu_panic(void)
@@ -89,17 +101,6 @@ void cpu_panic(void)
 
 struct linux_prom_registers smp_penguin_ctable __initdata = { 0 };
 
-void __init smp_boot_cpus(void)
-{
-	extern void smp4m_boot_cpus(void);
-	extern void smp4d_boot_cpus(void);
-
-	if (sparc_cpu_model == sun4m)
-		smp4m_boot_cpus();
-	else
-		smp4d_boot_cpus();
-}
-
 void smp_send_reschedule(int cpu)
 {
 	/* See sparc64 */
@@ -252,20 +253,61 @@ int setup_profiling_timer(unsigned int multiplier)
 	return 0;
 }
 
-void __init smp_prepare_cpus(unsigned int maxcpus)
+void __init smp_prepare_cpus(unsigned int max_cpus)
 {
+	extern void smp4m_boot_cpus(void);
+	int i, cpuid, ncpus, extra;
+
+	BUG_ON(sparc_cpu_model != sun4m);
+	printk("Entering SMP Mode...\n");
+
+	ncpus = 1;
+	extra = 0;
+	for (i = 0; !cpu_find_by_instance(i, NULL, &cpuid); i++) {
+		if (cpuid == boot_cpu_id)
+			continue;
+		if (cpuid < NR_CPUS && ncpus++ < max_cpus)
+			cpu_set(cpuid, phys_cpu_present_map);
+		else
+			extra++;
+	}
+	if (max_cpus >= NR_CPUS && extra)
+		printk("Warning: NR_CPUS is too low to start all cpus\n");
+
+	smp_store_cpu_info(boot_cpu_id);
+
+	smp4m_boot_cpus();
 }
 
 void __devinit smp_prepare_boot_cpu(void)
 {
-	current_thread_info()->cpu = hard_smp_processor_id();
-	cpu_set(smp_processor_id(), cpu_online_map);
-	cpu_set(smp_processor_id(), phys_cpu_present_map);
+	int cpuid = hard_smp_processor_id();
+
+	if (cpuid >= NR_CPUS) {
+		prom_printf("Serious problem, boot cpu id >= NR_CPUS\n");
+		prom_halt();
+	}
+	if (cpuid != 0)
+		printk("boot cpu id != 0, this could work but is untested\n");
+
+	current_thread_info()->cpu = cpuid;
+	cpu_set(cpuid, cpu_online_map);
+	cpu_set(cpuid, phys_cpu_present_map);
 }
 
 int __devinit __cpu_up(unsigned int cpu)
 {
-	panic("smp doesn't work\n");
+	extern int smp4m_boot_one_cpu(int);
+	int ret;
+
+	ret = smp4m_boot_one_cpu(cpu);
+
+	if (!ret) {
+		cpu_set(cpu, smp_commenced_mask);
+		while (!cpu_online(cpu))
+			mb();
+	}
+	return ret;
 }
 
 void smp_bogo(struct seq_file *m)

arch/sparc/kernel/sparc_ksyms.c

@@ -136,10 +136,6 @@ EXPORT_PER_CPU_SYMBOL(__cpu_data);
 /* IRQ implementation. */
 EXPORT_SYMBOL(synchronize_irq);
 
-/* Misc SMP information */
-EXPORT_SYMBOL(__cpu_number_map);
-EXPORT_SYMBOL(__cpu_logical_map);
-
 /* CPU online map and active count. */
 EXPORT_SYMBOL(cpu_online_map);
 EXPORT_SYMBOL(phys_cpu_present_map);

arch/sparc/kernel/sun4d_irq.c

@@ -54,7 +54,7 @@ unsigned char cpu_leds[32];
 unsigned char sbus_tid[32];
 #endif
 
-extern struct irqaction *irq_action[];
+static struct irqaction *irq_action[NR_IRQS];
 extern spinlock_t irq_action_lock;
 
 struct sbus_action {

arch/sparc/kernel/sun4d_smp.c

@@ -46,14 +46,16 @@ extern volatile int smp_processors_ready;
 extern int smp_num_cpus;
 static int smp_highest_cpu;
 extern volatile unsigned long cpu_callin_map[NR_CPUS];
-extern struct cpuinfo_sparc cpu_data[NR_CPUS];
+extern cpuinfo_sparc cpu_data[NR_CPUS];
 extern unsigned char boot_cpu_id;
 extern int smp_activated;
 extern volatile int __cpu_number_map[NR_CPUS];
 extern volatile int __cpu_logical_map[NR_CPUS];
 extern volatile unsigned long ipi_count;
 extern volatile int smp_process_available;
-extern volatile int smp_commenced;
+
+extern cpumask_t smp_commenced_mask;
+
 extern int __smp4d_processor_id(void);
 
 /* #define SMP_DEBUG */
@@ -136,7 +138,7 @@ void __init smp4d_callin(void)
 
 	local_irq_enable();	/* We don't allow PIL 14 yet */
 
-	while(!smp_commenced)
+	while (!cpu_isset(cpuid, smp_commenced_mask))
 		barrier();
 
 	spin_lock_irqsave(&sun4d_imsk_lock, flags);