Merge tag 'xtensa-20190307' of git://github.com/jcmvbkbc/linux-xtensa

Pull xtensa updates from Max Filippov:

 - use generic spinlock/rwlock implementations

 - clean up IPI processing

 - document boot parameters passing to the kernel

 - fix get_wchan

 - various cleanups in time.c, process.c, traps.c and thread_info.h

* tag 'xtensa-20190307' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: simplify trap_init
  xtensa: drop unused definitions
  xtensa: fix get_wchan
  xtensa: use generic spinlock/rwlock implementation
  xtensa: provide xchg for sizes 1 and 2
  xtensa: clean up arch/xtensa/kernel/time.c
  xtensa: SMP: rework IPI processing
  xtensa: document boot parameter passing

arch/xtensa/kernel/process.c

@@ -52,8 +52,6 @@
 extern void ret_from_fork(void);
 extern void ret_from_kernel_thread(void);
 
-struct task_struct *current_set[NR_CPUS] = {&init_task, };
-
 void (*pm_power_off)(void) = NULL;
 EXPORT_SYMBOL(pm_power_off);
 
@@ -321,8 +319,8 @@ unsigned long get_wchan(struct task_struct *p)
 
 		/* Stack layout: sp-4: ra, sp-3: sp' */
 
-		pc = MAKE_PC_FROM_RA(*(unsigned long*)sp - 4, sp);
-		sp = *(unsigned long *)sp - 3;
+		pc = MAKE_PC_FROM_RA(SPILL_SLOT(sp, 0), sp);
+		sp = SPILL_SLOT(sp, 1);
 	} while (count++ < 16);
 	return 0;
 }

arch/xtensa/kernel/smp.c

@@ -372,8 +372,7 @@ static void send_ipi_message(const struct cpumask *callmask,
 	unsigned long mask = 0;
 
 	for_each_cpu(index, callmask)
-		if (index != smp_processor_id())
-			mask |= 1 << index;
+		mask |= 1 << index;
 
 	set_er(mask, MIPISET(msg_id));
 }
@@ -412,22 +411,31 @@ irqreturn_t ipi_interrupt(int irq, void *dev_id)
 {
 	unsigned int cpu = smp_processor_id();
 	struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
-	unsigned int msg;
-	unsigned i;
 
-	msg = get_er(MIPICAUSE(cpu));
-	for (i = 0; i < IPI_MAX; i++)
-		if (msg & (1 << i)) {
-			set_er(1 << i, MIPICAUSE(cpu));
-			++ipi->ipi_count[i];
+	for (;;) {
+		unsigned int msg;
+
+		msg = get_er(MIPICAUSE(cpu));
+		set_er(msg, MIPICAUSE(cpu));
+
+		if (!msg)
+			break;
+
+		if (msg & (1 << IPI_CALL_FUNC)) {
+			++ipi->ipi_count[IPI_CALL_FUNC];
+			generic_smp_call_function_interrupt();
 		}
 
-	if (msg & (1 << IPI_RESCHEDULE))
-		scheduler_ipi();
-	if (msg & (1 << IPI_CALL_FUNC))
-		generic_smp_call_function_interrupt();
-	if (msg & (1 << IPI_CPU_STOP))
-		ipi_cpu_stop(cpu);
+		if (msg & (1 << IPI_RESCHEDULE)) {
+			++ipi->ipi_count[IPI_RESCHEDULE];
+			scheduler_ipi();
+		}
+
+		if (msg & (1 << IPI_CPU_STOP)) {
+			++ipi->ipi_count[IPI_CPU_STOP];
+			ipi_cpu_stop(cpu);
+		}
+	}
 
 	return IRQ_HANDLED;
 }

arch/xtensa/kernel/time.c

@@ -52,14 +52,11 @@ static struct clocksource ccount_clocksource = {
 	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
-static int ccount_timer_set_next_event(unsigned long delta,
-		struct clock_event_device *dev);
 struct ccount_timer {
 	struct clock_event_device evt;
 	int irq_enabled;
 	char name[24];
 };
-static DEFINE_PER_CPU(struct ccount_timer, ccount_timer);
 
 static int ccount_timer_set_next_event(unsigned long delta,
 		struct clock_event_device *dev)
@@ -107,7 +104,30 @@ static int ccount_timer_set_oneshot(struct clock_event_device *evt)
 	return 0;
 }
 
-static irqreturn_t timer_interrupt(int irq, void *dev_id);
+static DEFINE_PER_CPU(struct ccount_timer, ccount_timer) = {
+	.evt = {
+		.features = CLOCK_EVT_FEAT_ONESHOT,
+		.rating = 300,
+		.set_next_event = ccount_timer_set_next_event,
+		.set_state_shutdown = ccount_timer_shutdown,
+		.set_state_oneshot = ccount_timer_set_oneshot,
+		.tick_resume = ccount_timer_set_oneshot,
+	},
+};
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = &this_cpu_ptr(&ccount_timer)->evt;
+
+	set_linux_timer(get_linux_timer());
+	evt->event_handler(evt);
+
+	/* Allow platform to do something useful (Wdog). */
+	platform_heartbeat();
+
+	return IRQ_HANDLED;
+}
+
 static struct irqaction timer_irqaction = {
 	.handler =	timer_interrupt,
 	.flags =	IRQF_TIMER,
@@ -120,14 +140,8 @@ void local_timer_setup(unsigned cpu)
 	struct clock_event_device *clockevent = &timer->evt;
 
 	timer->irq_enabled = 1;
-	clockevent->name = timer->name;
 	snprintf(timer->name, sizeof(timer->name), "ccount_clockevent_%u", cpu);
-	clockevent->features = CLOCK_EVT_FEAT_ONESHOT;
-	clockevent->rating = 300;
-	clockevent->set_next_event = ccount_timer_set_next_event;
-	clockevent->set_state_shutdown = ccount_timer_shutdown;
-	clockevent->set_state_oneshot = ccount_timer_set_oneshot;
-	clockevent->tick_resume = ccount_timer_set_oneshot;
+	clockevent->name = timer->name;
 	clockevent->cpumask = cpumask_of(cpu);
 	clockevent->irq = irq_create_mapping(NULL, LINUX_TIMER_INT);
 	if (WARN(!clockevent->irq, "error: can't map timer irq"))
@@ -190,23 +204,6 @@ void __init time_init(void)
 	timer_probe();
 }
 
-/*
- * The timer interrupt is called HZ times per second.
- */
-
-irqreturn_t timer_interrupt(int irq, void *dev_id)
-{
-	struct clock_event_device *evt = &this_cpu_ptr(&ccount_timer)->evt;
-
-	set_linux_timer(get_linux_timer());
-	evt->event_handler(evt);
-
-	/* Allow platform to do something useful (Wdog). */
-	platform_heartbeat();
-
-	return IRQ_HANDLED;
-}
-
 #ifndef CONFIG_GENERIC_CALIBRATE_DELAY
 void calibrate_delay(void)
 {

arch/xtensa/kernel/traps.c

@@ -420,16 +420,15 @@ void __init trap_init(void)
 	/* Setup specific handlers. */
 
 	for(i = 0; dispatch_init_table[i].cause >= 0; i++) {
-
 		int fast = dispatch_init_table[i].fast;
 		int cause = dispatch_init_table[i].cause;
 		void *handler = dispatch_init_table[i].handler;
 
 		if (fast == 0)
 			set_handler(default_handler, cause, handler);
-		if (fast && fast & USER)
+		if ((fast & USER) != 0)
 			set_handler(fast_user_handler, cause, handler);
-		if (fast && fast & KRNL)
+		if ((fast & KRNL) != 0)
 			set_handler(fast_kernel_handler, cause, handler);
 	}