Merge branch into tip/master: 'irq/core'

# New commits in irq/core:
    b4706d814921 ("genirq/kexec: Prevent redundant IRQ masking by checking state before shutdown")
    bad6722e478f ("kexec: Consolidate machine_kexec_mask_interrupts() implementation")
    429f49ad361c ("genirq: Reuse irq_thread_fn() for forced thread case")
    6f8b79683dfb ("genirq: Move irq_thread_fn() further up in the code")

Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/arm/kernel/machine_kexec.c

@@ -127,29 +127,6 @@ void crash_smp_send_stop(void)
 	cpus_stopped = 1;
 }
 
-static void machine_kexec_mask_interrupts(void)
-{
-	unsigned int i;
-	struct irq_desc *desc;
-
-	for_each_irq_desc(i, desc) {
-		struct irq_chip *chip;
-
-		chip = irq_desc_get_chip(desc);
-		if (!chip)
-			continue;
-
-		if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
-			chip->irq_eoi(&desc->irq_data);
-
-		if (chip->irq_mask)
-			chip->irq_mask(&desc->irq_data);
-
-		if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
-			chip->irq_disable(&desc->irq_data);
-	}
-}
-
 void machine_crash_shutdown(struct pt_regs *regs)
 {
 	local_irq_disable();

arch/arm64/Kconfig

@@ -149,6 +149,7 @@ config ARM64
 	select GENERIC_IDLE_POLL_SETUP
 	select GENERIC_IOREMAP
 	select GENERIC_IRQ_IPI
+	select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_SHOW_LEVEL

arch/arm64/kernel/machine_kexec.c

@@ -207,37 +207,6 @@ void machine_kexec(struct kimage *kimage)
 	BUG(); /* Should never get here. */
 }
 
-static void machine_kexec_mask_interrupts(void)
-{
-	unsigned int i;
-	struct irq_desc *desc;
-
-	for_each_irq_desc(i, desc) {
-		struct irq_chip *chip;
-		int ret;
-
-		chip = irq_desc_get_chip(desc);
-		if (!chip)
-			continue;
-
-		/*
-		 * First try to remove the active state. If this
-		 * fails, try to EOI the interrupt.
-		 */
-		ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
-
-		if (ret && irqd_irq_inprogress(&desc->irq_data) &&
-		    chip->irq_eoi)
-			chip->irq_eoi(&desc->irq_data);
-
-		if (chip->irq_mask)
-			chip->irq_mask(&desc->irq_data);
-
-		if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
-			chip->irq_disable(&desc->irq_data);
-	}
-}
-
 /**
  * machine_crash_shutdown - shutdown non-crashing cpus and save registers
  */

arch/powerpc/include/asm/kexec.h

@@ -61,7 +61,6 @@ struct pt_regs;
 extern void kexec_smp_wait(void);	/* get and clear naca physid, wait for
 					  master to copy new code to 0 */
 extern void default_machine_kexec(struct kimage *image);
-extern void machine_kexec_mask_interrupts(void);
 
 void relocate_new_kernel(unsigned long indirection_page, unsigned long reboot_code_buffer,
 			 unsigned long start_address) __noreturn;

arch/powerpc/kexec/core.c

@@ -22,28 +22,6 @@
 #include <asm/setup.h>
 #include <asm/firmware.h>
 
-void machine_kexec_mask_interrupts(void) {
-	unsigned int i;
-	struct irq_desc *desc;
-
-	for_each_irq_desc(i, desc) {
-		struct irq_chip *chip;
-
-		chip = irq_desc_get_chip(desc);
-		if (!chip)
-			continue;
-
-		if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
-			chip->irq_eoi(&desc->irq_data);
-
-		if (chip->irq_mask)
-			chip->irq_mask(&desc->irq_data);
-
-		if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
-			chip->irq_disable(&desc->irq_data);
-	}
-}
-
 #ifdef CONFIG_CRASH_DUMP
 void machine_crash_shutdown(struct pt_regs *regs)
 {

arch/powerpc/kexec/core_32.c

@@ -7,6 +7,7 @@
  * Copyright (C) 2005 IBM Corporation.
  */
 
+#include <linux/irq.h>
 #include <linux/kexec.h>
 #include <linux/mm.h>
 #include <linux/string.h>

arch/riscv/kernel/machine_kexec.c

@@ -114,29 +114,6 @@ void machine_shutdown(void)
 #endif
 }
 
-static void machine_kexec_mask_interrupts(void)
-{
-	unsigned int i;
-	struct irq_desc *desc;
-
-	for_each_irq_desc(i, desc) {
-		struct irq_chip *chip;
-
-		chip = irq_desc_get_chip(desc);
-		if (!chip)
-			continue;
-
-		if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
-			chip->irq_eoi(&desc->irq_data);
-
-		if (chip->irq_mask)
-			chip->irq_mask(&desc->irq_data);
-
-		if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
-			chip->irq_disable(&desc->irq_data);
-	}
-}
-
 /*
  * machine_crash_shutdown - Prepare to kexec after a kernel crash
  *

include/linux/irq.h

@@ -694,6 +694,9 @@ extern int irq_chip_request_resources_parent(struct irq_data *data);
 extern void irq_chip_release_resources_parent(struct irq_data *data);
 #endif
 
+/* Disable or mask interrupts during a kernel kexec */
+extern void machine_kexec_mask_interrupts(void);
+
 /* Handling of unhandled and spurious interrupts: */
 extern void note_interrupt(struct irq_desc *desc, irqreturn_t action_ret);
 

kernel/irq/Kconfig

@@ -141,6 +141,12 @@ config GENERIC_IRQ_DEBUGFS
 
 	  If you don't know what to do here, say N.
 
+# Clear forwarded VM interrupts during kexec.
+# This option ensures the kernel clears active states for interrupts
+# forwarded to virtual machines (VMs) during a machine kexec.
+config GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
+	bool
+
 endmenu
 
 config GENERIC_IRQ_MULTI_HANDLER

kernel/irq/Makefile

@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 
-obj-y := irqdesc.o handle.o manage.o spurious.o resend.o chip.o dummychip.o devres.o
+obj-y := irqdesc.o handle.o manage.o spurious.o resend.o chip.o dummychip.o devres.o kexec.o
 obj-$(CONFIG_IRQ_TIMINGS) += timings.o
 ifeq ($(CONFIG_TEST_IRQ_TIMINGS),y)
 	CFLAGS_timings.o += -DDEBUG

kernel/irq/kexec.c

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdesc.h>
+#include <linux/irqnr.h>
+
+#include "internals.h"
+
+void machine_kexec_mask_interrupts(void)
+{
+	struct irq_desc *desc;
+	unsigned int i;
+
+	for_each_irq_desc(i, desc) {
+		struct irq_chip *chip;
+		int check_eoi = 1;
+
+		chip = irq_desc_get_chip(desc);
+		if (!chip || !irqd_is_started(&desc->irq_data))
+			continue;
+
+		if (IS_ENABLED(CONFIG_GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD)) {
+			/*
+			 * First try to remove the active state from an interrupt which is forwarded
+			 * to a VM. If the interrupt is not forwarded, try to EOI the interrupt.
+			 */
+			check_eoi = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
+		}
+
+		if (check_eoi && chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
+			chip->irq_eoi(&desc->irq_data);
+
+		irq_shutdown(desc);
+	}
+}

kernel/irq/manage.c

@@ -1181,49 +1181,42 @@ out_unlock:
 	chip_bus_sync_unlock(desc);
 }
 
+/*
+ * Interrupts explicitly requested as threaded interrupts want to be
+ * preemptible - many of them need to sleep and wait for slow busses to
+ * complete.
+ */
+static irqreturn_t irq_thread_fn(struct irq_desc *desc,	struct irqaction *action)
+{
+	irqreturn_t ret = action->thread_fn(action->irq, action->dev_id);
+
+	if (ret == IRQ_HANDLED)
+		atomic_inc(&desc->threads_handled);
+
+	irq_finalize_oneshot(desc, action);
+	return ret;
+}
+
 /*
  * Interrupts which are not explicitly requested as threaded
  * interrupts rely on the implicit bh/preempt disable of the hard irq
  * context. So we need to disable bh here to avoid deadlocks and other
  * side effects.
  */
-static irqreturn_t
-irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
+static irqreturn_t irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
 {
 	irqreturn_t ret;
 
 	local_bh_disable();
 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 		local_irq_disable();
-	ret = action->thread_fn(action->irq, action->dev_id);
-	if (ret == IRQ_HANDLED)
-		atomic_inc(&desc->threads_handled);
-
-	irq_finalize_oneshot(desc, action);
+	ret = irq_thread_fn(desc, action);
 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 		local_irq_enable();
 	local_bh_enable();
 	return ret;
 }
 
-/*
- * Interrupts explicitly requested as threaded interrupts want to be
- * preemptible - many of them need to sleep and wait for slow busses to
- * complete.
- */
-static irqreturn_t irq_thread_fn(struct irq_desc *desc,
-		struct irqaction *action)
-{
-	irqreturn_t ret;
-
-	ret = action->thread_fn(action->irq, action->dev_id);
-	if (ret == IRQ_HANDLED)
-		atomic_inc(&desc->threads_handled);
-
-	irq_finalize_oneshot(desc, action);
-	return ret;
-}
-
 void wake_threads_waitq(struct irq_desc *desc)
 {
 	if (atomic_dec_and_test(&desc->threads_active))