smp: refine bf561 smpboot code

release boot lock earlier to let coreb do setup and calibrate
set coreb online later after initialization ready
add BFIN_IPI_NONE IPI type
drop unnecesarry smp_mb() and using atomic type
Signed-off-by: Steven Miao <realmz6@gmail.com>

arch/blackfin/mach-bf561/smp.c

@@ -69,7 +69,6 @@ void __cpuinit platform_secondary_init(unsigned int cpu)
 	SSYNC();
 
 	/* We are done with local CPU inits, unblock the boot CPU. */
-	set_cpu_online(cpu, true);
 	spin_lock(&boot_lock);
 	spin_unlock(&boot_lock);
 }
@@ -91,7 +90,9 @@ int __cpuinit platform_boot_secondary(unsigned int cpu, struct task_struct *idle
 		SSYNC();
 	}
 
-	timeout = jiffies + 1 * HZ;
+	timeout = jiffies + HZ;
+	/* release the lock and let coreb run */
+	spin_unlock(&boot_lock);
 	while (time_before(jiffies, timeout)) {
 		if (cpu_online(cpu))
 			break;
@@ -100,8 +101,6 @@ int __cpuinit platform_boot_secondary(unsigned int cpu, struct task_struct *idle
 	}
 
 	if (cpu_online(cpu)) {
-		/* release the lock and let coreb run */
-		spin_unlock(&boot_lock);
 		return 0;
 	} else
 		panic("CPU%u: processor failed to boot\n", cpu);

arch/blackfin/mach-common/smp.c

@@ -49,6 +49,7 @@ unsigned long blackfin_iflush_l1_entry[NR_CPUS];
 struct blackfin_initial_pda __cpuinitdata initial_pda_coreb;
 
 enum ipi_message_type {
+	BFIN_IPI_NONE,
 	BFIN_IPI_TIMER,
 	BFIN_IPI_RESCHEDULE,
 	BFIN_IPI_CALL_FUNC,
@@ -72,8 +73,8 @@ static DEFINE_SPINLOCK(stop_lock);
 
 /* Simple FIFO buffer, overflow leads to panic */
 struct ipi_data {
-	unsigned long count;
-	unsigned long bits;
+	atomic_t count;
+	atomic_t bits;
 };
 
 static DEFINE_PER_CPU(struct ipi_data, bfin_ipi);
@@ -146,7 +147,6 @@ static irqreturn_t ipi_handler_int1(int irq, void *dev_instance)
 	platform_clear_ipi(cpu, IRQ_SUPPLE_1);
 
 	bfin_ipi_data = &__get_cpu_var(bfin_ipi);
-	smp_mb();
 	while ((pending = xchg(&bfin_ipi_data->bits, 0)) != 0) {
 		msg = 0;
 		do {
@@ -170,9 +170,8 @@ static irqreturn_t ipi_handler_int1(int irq, void *dev_instance)
 				ipi_cpu_stop(cpu);
 				break;
 			}
+			atomic_dec(&bfin_ipi_data->count);
 		} while (msg < BITS_PER_LONG);
-
-		smp_mb();
 	}
 	return IRQ_HANDLED;
 }
@@ -195,12 +194,10 @@ void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg)
 	unsigned long flags;
 
 	local_irq_save(flags);
-	smp_mb();
 	for_each_cpu(cpu, cpumask) {
 		bfin_ipi_data = &per_cpu(bfin_ipi, cpu);
-		smp_mb();
-		set_bit(msg, &bfin_ipi_data->bits);
-		bfin_ipi_data->count++;
+		atomic_set_mask((1 << msg), &bfin_ipi_data->bits);
+		atomic_inc(&bfin_ipi_data->count);
 		platform_send_ipi_cpu(cpu, IRQ_SUPPLE_1);
 	}
 
@@ -319,7 +316,6 @@ void __cpuinit secondary_start_kernel(void)
 	setup_secondary(cpu);
 
 	platform_secondary_init(cpu);
-
 	/* setup local core timer */
 	bfin_local_timer_setup();
 
@@ -335,6 +331,8 @@ void __cpuinit secondary_start_kernel(void)
 	 */
 	calibrate_delay();
 
+	/* We are done with local CPU inits, unblock the boot CPU. */
+	set_cpu_online(cpu, true);
 	cpu_startup_entry(CPUHP_ONLINE);
 }