Merge tag 'irq-core-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "The usual updates from the irq departement:

  Core changes:

   - Provide IRQF_NO_AUTOEN as a flag for request*_irq() so drivers can
     be cleaned up which either use a seperate mechanism to prevent
     auto-enable at request time or have a racy mechanism which disables
     the interrupt right after request.

   - Get rid of the last usage of irq_create_identity_mapping() and
     remove the interface.

   - An overhaul of tasklet_disable().

     Most usage sites of tasklet_disable() are in task context and
     usually in cleanup, teardown code pathes. tasklet_disable()
     spinwaits for a tasklet which is currently executed. That's not
     only a problem for PREEMPT_RT where this can lead to a live lock
     when the disabling task preempts the softirq thread. It's also
     problematic in context of virtualization when the vCPU which runs
     the tasklet is scheduled out and the disabling code has to spin
     wait until it's scheduled back in.

     There are a few code pathes which invoke tasklet_disable() from
     non-sleepable context. For these a new disable variant which still
     spinwaits is provided which allows to switch tasklet_disable() to a
     sleep wait mechanism. For the atomic use cases this does not solve
     the live lock issue on PREEMPT_RT. That is mitigated by blocking on
     the RT specific softirq lock.

   - The PREEMPT_RT specific implementation of softirq processing and
     local_bh_disable/enable().

     On RT enabled kernels soft interrupt processing happens always in
     task context and all interrupt handlers, which are not explicitly
     marked to be invoked in hard interrupt context are forced into task
     context as well. This allows to protect against softirq processing
     with a per CPU lock, which in turn allows to make BH disabled
     regions preemptible.

     Most of the softirq handling code is still shared. The RT/non-RT
     specific differences are addressed with a set of inline functions
     which provide the context specific functionality. The
     local_bh_disable() / local_bh_enable() mechanism are obviously
     seperate.

   - The usual set of small improvements and cleanups

  Driver changes:

   - New drivers for Nuvoton WPCM450 and DT 79rc3243x interrupt
     controllers

   - Extended functionality for MStar, STM32 and SC7280 irq chips

   - Enhanced robustness for ARM GICv3/4.1 drivers

   - The usual set of cleanups and improvements all over the place"

* tag 'irq-core-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  irqchip/xilinx: Expose Kconfig option for Zynq/ZynqMP
  irqchip/gic-v3: Do not enable irqs when handling spurious interrups
  dt-bindings: interrupt-controller: Add IDT 79RC3243x Interrupt Controller
  irqchip: Add support for IDT 79rc3243x interrupt controller
  irqdomain: Drop references to recusive irqdomain setup
  irqdomain: Get rid of irq_create_strict_mappings()
  irqchip/jcore-aic: Kill use of irq_create_strict_mappings()
  ARM: PXA: Kill use of irq_create_strict_mappings()
  irqchip/gic-v4.1: Disable vSGI upon (GIC CPUIF < v4.1) detection
  irqchip/tb10x: Use 'fallthrough' to eliminate a warning
  genirq: Reduce irqdebug cacheline bouncing
  kernel: Initialize cpumask before parsing
  irqchip/wpcm450: Drop COMPILE_TEST
  irqchip/irq-mst: Support polarity configuration
  irqchip: Add driver for WPCM450 interrupt controller
  dt-bindings: interrupt-controller: Add nuvoton, wpcm450-aic
  dt-bindings: qcom,pdc: Add compatible for sc7280
  irqchip/stm32: Add usart instances exti direct event support
  irqchip/gic-v3: Fix OF_BAD_ADDR error handling
  irqchip/sifive-plic: Mark two global variables __ro_after_init
  ...

1 files changed, 15 insertions, 8 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 21ea370fccda..4c14356543d9 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -179,7 +179,7 @@ bool irq_can_set_affinity_usr(unsigned int irq)
 
 /**
  *	irq_set_thread_affinity - Notify irq threads to adjust affinity
- *	@desc:		irq descriptor which has affitnity changed
+ *	@desc:		irq descriptor which has affinity changed
  *
  *	We just set IRQTF_AFFINITY and delegate the affinity setting
  *	to the interrupt thread itself. We can not call
@@ -326,7 +326,7 @@ static bool irq_set_affinity_deactivated(struct irq_data *data,
 	 * If the interrupt is not yet activated, just store the affinity
 	 * mask and do not call the chip driver at all. On activation the
 	 * driver has to make sure anyway that the interrupt is in a
-	 * useable state so startup works.
+	 * usable state so startup works.
 	 */
 	if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
 	    irqd_is_activated(data) || !irqd_affinity_on_activate(data))
@@ -1054,7 +1054,7 @@ again:
 	 * to IRQS_INPROGRESS and the irq line is masked forever.
 	 *
 	 * This also serializes the state of shared oneshot handlers
-	 * versus "desc->threads_onehsot |= action->thread_mask;" in
+	 * versus "desc->threads_oneshot |= action->thread_mask;" in
 	 * irq_wake_thread(). See the comment there which explains the
 	 * serialization.
 	 */
@@ -1157,7 +1157,7 @@ irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
 
 /*
  * Interrupts explicitly requested as threaded interrupts want to be
- * preemtible - many of them need to sleep and wait for slow busses to
+ * preemptible - many of them need to sleep and wait for slow busses to
  * complete.
  */
 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
@@ -1697,7 +1697,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 			irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
 		}
 
-		if (irq_settings_can_autoenable(desc)) {
+		if (!(new->flags & IRQF_NO_AUTOEN) &&
+		    irq_settings_can_autoenable(desc)) {
 			irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
 		} else {
 			/*
@@ -1912,7 +1913,7 @@ static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
 	/* Last action releases resources */
 	if (!desc->action) {
 		/*
-		 * Reaquire bus lock as irq_release_resources() might
+		 * Reacquire bus lock as irq_release_resources() might
 		 * require it to deallocate resources over the slow bus.
 		 */
 		chip_bus_lock(desc);
@@ -2090,10 +2091,15 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
 	 * which interrupt is which (messes up the interrupt freeing
 	 * logic etc).
 	 *
+	 * Also shared interrupts do not go well with disabling auto enable.
+	 * The sharing interrupt might request it while it's still disabled
+	 * and then wait for interrupts forever.
+	 *
 	 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
 	 * it cannot be set along with IRQF_NO_SUSPEND.
 	 */
 	if (((irqflags & IRQF_SHARED) && !dev_id) ||
+	    ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
 	    (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
 	    ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
 		return -EINVAL;
@@ -2249,7 +2255,8 @@ int request_nmi(unsigned int irq, irq_handler_t handler,
 
 	desc = irq_to_desc(irq);
 
-	if (!desc || irq_settings_can_autoenable(desc) ||
+	if (!desc || (irq_settings_can_autoenable(desc) &&
+	    !(irqflags & IRQF_NO_AUTOEN)) ||
 	    !irq_settings_can_request(desc) ||
 	    WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
 	    !irq_supports_nmi(desc))
@@ -2746,7 +2753,7 @@ int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
  *	irq_get_irqchip_state - returns the irqchip state of a interrupt.
  *	@irq: Interrupt line that is forwarded to a VM
  *	@which: One of IRQCHIP_STATE_* the caller wants to know about
- *	@state: a pointer to a boolean where the state is to be storeed
+ *	@state: a pointer to a boolean where the state is to be stored
  *
  *	This call snapshots the internal irqchip state of an
  *	interrupt, returning into @state the bit corresponding to