Merge tag 'irqchip-fixes-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip fixes from Marc Zyngier:

  - A couple of fixes after the IPI as IRQ patches (Kconfig, bcm2836)
  - Two SiFive PLIC fixes (irq_set_affinity, hierarchy handling)
  - "unmapped events" handling for the ti-sci-inta controller
  - Tidying up for the irq-mst driver (static functions, Kconfig)
  - Small cleanup in the Renesas irqpin driver
  - STM32 exti can now handle LP timer events

4 files changed, 100 insertions, 53 deletions

diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 7fff88e61252..7a4853b1213a 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -547,7 +547,7 @@ static int arch_build_bp_info(struct perf_event *bp,
 		if ((hw->ctrl.type != ARM_BREAKPOINT_EXECUTE)
 			&& max_watchpoint_len >= 8)
 			break;
-		/* Else, fall through */
+		fallthrough;
 	default:
 		return -EINVAL;
 	}
@@ -612,12 +612,12 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
 		/* Allow halfword watchpoints and breakpoints. */
 		if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
 			break;
-		/* Else, fall through */
+		fallthrough;
 	case 3:
 		/* Allow single byte watchpoint. */
 		if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
 			break;
-		/* Else, fall through */
+		fallthrough;
 	default:
 		ret = -EINVAL;
 		goto out;
@@ -884,7 +884,7 @@ static int hw_breakpoint_pending(unsigned long addr, unsigned int fsr,
 		break;
 	case ARM_ENTRY_ASYNC_WATCHPOINT:
 		WARN(1, "Asynchronous watchpoint exception taken. Debugging results may be unreliable\n");
-		/* Fall through */
+		fallthrough;
 	case ARM_ENTRY_SYNC_WATCHPOINT:
 		watchpoint_handler(addr, fsr, regs);
 		break;
@@ -933,7 +933,7 @@ static bool core_has_os_save_restore(void)
 		ARM_DBG_READ(c1, c1, 4, oslsr);
 		if (oslsr & ARM_OSLSR_OSLM0)
 			return true;
-		/* Else, fall through */
+		fallthrough;
 	default:
 		return false;
 	}
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index ee514034c0a1..698b6f636156 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -18,7 +18,6 @@
  *  IRQ's are in fact implemented a bit like signal handlers for the kernel.
  *  Naturally it's not a 1:1 relation, but there are similarities.
  */
-#include <linux/kernel_stat.h>
 #include <linux/signal.h>
 #include <linux/ioport.h>
 #include <linux/interrupt.h>
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index c9dc912b83f0..c1892f733f20 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -596,7 +596,7 @@ static int do_signal(struct pt_regs *regs, int syscall)
 		switch (retval) {
 		case -ERESTART_RESTARTBLOCK:
 			restart -= 2;
-			/* Fall through */
+			fallthrough;
 		case -ERESTARTNOHAND:
 		case -ERESTARTSYS:
 		case -ERESTARTNOINTR:
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 5d9da61eff62..48099c6e1e4a 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -26,6 +26,7 @@
 #include <linux/completion.h>
 #include <linux/cpufreq.h>
 #include <linux/irq_work.h>
+#include <linux/kernel_stat.h>
 
 #include <linux/atomic.h>
 #include <asm/bugs.h>
@@ -65,18 +66,26 @@ enum ipi_msg_type {
 	IPI_CPU_STOP,
 	IPI_IRQ_WORK,
 	IPI_COMPLETION,
+	NR_IPI,
 	/*
 	 * CPU_BACKTRACE is special and not included in NR_IPI
 	 * or tracable with trace_ipi_*
 	 */
-	IPI_CPU_BACKTRACE,
+	IPI_CPU_BACKTRACE = NR_IPI,
 	/*
 	 * SGI8-15 can be reserved by secure firmware, and thus may
 	 * not be usable by the kernel. Please keep the above limited
 	 * to at most 8 entries.
 	 */
+	MAX_IPI
 };
 
+static int ipi_irq_base __read_mostly;
+static int nr_ipi __read_mostly = NR_IPI;
+static struct irq_desc *ipi_desc[MAX_IPI] __read_mostly;
+
+static void ipi_setup(int cpu);
+
 static DECLARE_COMPLETION(cpu_running);
 
 static struct smp_operations smp_ops __ro_after_init;
@@ -226,6 +235,17 @@ int platform_can_hotplug_cpu(unsigned int cpu)
 	return cpu != 0;
 }
 
+static void ipi_teardown(int cpu)
+{
+	int i;
+
+	if (WARN_ON_ONCE(!ipi_irq_base))
+		return;
+
+	for (i = 0; i < nr_ipi; i++)
+		disable_percpu_irq(ipi_irq_base + i);
+}
+
 /*
  * __cpu_disable runs on the processor to be shutdown.
  */
@@ -247,6 +267,7 @@ int __cpu_disable(void)
 	 * and we must not schedule until we're ready to give up the cpu.
 	 */
 	set_cpu_online(cpu, false);
+	ipi_teardown(cpu);
 
 	/*
 	 * OK - migrate IRQs away from this CPU
@@ -422,6 +443,8 @@ asmlinkage void secondary_start_kernel(void)
 
 	notify_cpu_starting(cpu);
 
+	ipi_setup(cpu);
+
 	calibrate_delay();
 
 	smp_store_cpu_info(cpu);
@@ -500,14 +523,6 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 	}
 }
 
-static void (*__smp_cross_call)(const struct cpumask *, unsigned int);
-
-void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int))
-{
-	if (!__smp_cross_call)
-		__smp_cross_call = fn;
-}
-
 static const char *ipi_types[NR_IPI] __tracepoint_string = {
 #define S(x,s)	[x] = s
 	S(IPI_WAKEUP, "CPU wakeup interrupts"),
@@ -519,38 +534,28 @@ static const char *ipi_types[NR_IPI] __tracepoint_string = {
 	S(IPI_COMPLETION, "completion interrupts"),
 };
 
-static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
-{
-	trace_ipi_raise_rcuidle(target, ipi_types[ipinr]);
-	__smp_cross_call(target, ipinr);
-}
+static void smp_cross_call(const struct cpumask *target, unsigned int ipinr);
 
 void show_ipi_list(struct seq_file *p, int prec)
 {
 	unsigned int cpu, i;
 
 	for (i = 0; i < NR_IPI; i++) {
+		unsigned int irq;
+
+		if (!ipi_desc[i])
+			continue;
+
+		irq = irq_desc_get_irq(ipi_desc[i]);
 		seq_printf(p, "%*s%u: ", prec - 1, "IPI", i);
 
 		for_each_online_cpu(cpu)
-			seq_printf(p, "%10u ",
-				   __get_irq_stat(cpu, ipi_irqs[i]));
+			seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
 
 		seq_printf(p, " %s\n", ipi_types[i]);
 	}
 }
 
-u64 smp_irq_stat_cpu(unsigned int cpu)
-{
-	u64 sum = 0;
-	int i;
-
-	for (i = 0; i < NR_IPI; i++)
-		sum += __get_irq_stat(cpu, ipi_irqs[i]);
-
-	return sum;
-}
-
 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 {
 	smp_cross_call(mask, IPI_CALL_FUNC);
@@ -627,15 +632,12 @@ asmlinkage void __exception_irq_entry do_IPI(int ipinr, struct pt_regs *regs)
 	handle_IPI(ipinr, regs);
 }
 
-void handle_IPI(int ipinr, struct pt_regs *regs)
+static void do_handle_IPI(int ipinr)
 {
 	unsigned int cpu = smp_processor_id();
-	struct pt_regs *old_regs = set_irq_regs(regs);
 
-	if ((unsigned)ipinr < NR_IPI) {
+	if ((unsigned)ipinr < NR_IPI)
 		trace_ipi_entry_rcuidle(ipi_types[ipinr]);
-		__inc_irq_stat(cpu, ipi_irqs[ipinr]);
-	}
 
 	switch (ipinr) {
 	case IPI_WAKEUP:
@@ -643,9 +645,7 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
 
 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 	case IPI_TIMER:
-		irq_enter();
 		tick_receive_broadcast();
-		irq_exit();
 		break;
 #endif
 
@@ -654,36 +654,26 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
 		break;
 
 	case IPI_CALL_FUNC:
-		irq_enter();
 		generic_smp_call_function_interrupt();
-		irq_exit();
 		break;
 
 	case IPI_CPU_STOP:
-		irq_enter();
 		ipi_cpu_stop(cpu);
-		irq_exit();
 		break;
 
 #ifdef CONFIG_IRQ_WORK
 	case IPI_IRQ_WORK:
-		irq_enter();
 		irq_work_run();
-		irq_exit();
 		break;
 #endif
 
 	case IPI_COMPLETION:
-		irq_enter();
 		ipi_complete(cpu);
-		irq_exit();
 		break;
 
 	case IPI_CPU_BACKTRACE:
 		printk_nmi_enter();
-		irq_enter();
-		nmi_cpu_backtrace(regs);
-		irq_exit();
+		nmi_cpu_backtrace(get_irq_regs());
 		printk_nmi_exit();
 		break;
 
@@ -695,9 +685,67 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
 
 	if ((unsigned)ipinr < NR_IPI)
 		trace_ipi_exit_rcuidle(ipi_types[ipinr]);
+}
+
+/* Legacy version, should go away once all irqchips have been converted */
+void handle_IPI(int ipinr, struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	irq_enter();
+	do_handle_IPI(ipinr);
+	irq_exit();
+
 	set_irq_regs(old_regs);
 }
 
+static irqreturn_t ipi_handler(int irq, void *data)
+{
+	do_handle_IPI(irq - ipi_irq_base);
+	return IRQ_HANDLED;
+}
+
+static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
+{
+	trace_ipi_raise_rcuidle(target, ipi_types[ipinr]);
+	__ipi_send_mask(ipi_desc[ipinr], target);
+}
+
+static void ipi_setup(int cpu)
+{
+	int i;
+
+	if (WARN_ON_ONCE(!ipi_irq_base))
+		return;
+
+	for (i = 0; i < nr_ipi; i++)
+		enable_percpu_irq(ipi_irq_base + i, 0);
+}
+
+void __init set_smp_ipi_range(int ipi_base, int n)
+{
+	int i;
+
+	WARN_ON(n < MAX_IPI);
+	nr_ipi = min(n, MAX_IPI);
+
+	for (i = 0; i < nr_ipi; i++) {
+		int err;
+
+		err = request_percpu_irq(ipi_base + i, ipi_handler,
+					 "IPI", &irq_stat);
+		WARN_ON(err);
+
+		ipi_desc[i] = irq_to_desc(ipi_base + i);
+		irq_set_status_flags(ipi_base + i, IRQ_HIDDEN);
+	}
+
+	ipi_irq_base = ipi_base;
+
+	/* Setup the boot CPU immediately */
+	ipi_setup(smp_processor_id());
+}
+
 void smp_send_reschedule(int cpu)
 {
 	smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
@@ -805,7 +853,7 @@ core_initcall(register_cpufreq_notifier);
 
 static void raise_nmi(cpumask_t *mask)
 {
-	__smp_cross_call(mask, IPI_CPU_BACKTRACE);
+	__ipi_send_mask(ipi_desc[IPI_CPU_BACKTRACE], mask);
 }
 
 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)