kernel/irq: Extend lockdep class for request mutex

The IRQ code already has support for lockdep class for the lock mutex
in an interrupt descriptor. Extend this to add a second class for the
request mutex in the descriptor. Not having a class is resulting in
false positive splats in some code paths.

Signed-off-by: Andrew Lunn <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Acked-by: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Link: https://lkml.kernel.org/r/[e-mail]

arch/powerpc/sysdev/fsl_msi.c

···
 }
 
 static struct lock_class_key fsl_msi_irq_class;
+static struct lock_class_key fsl_msi_irq_request_class;
 
 static int fsl_msi_setup_hwirq(struct fsl_msi *msi, struct platform_device *dev,
 			       int offset, int irq_index)
···
 		dev_err(&dev->dev, "No memory for MSI cascade data\n");
 		return -ENOMEM;
 	}
-	irq_set_lockdep_class(virt_msir, &fsl_msi_irq_class);
+	irq_set_lockdep_class(virt_msir, &fsl_msi_irq_class,
+			      &fsl_msi_irq_request_class);
 	cascade_data->index = offset;
 	cascade_data->msi_data = msi;
 	cascade_data->virq = virt_msir;

drivers/gpio/gpio-bcm-kona.c

···
  * category than their parents, so it won't report false recursion.
  */
 static struct lock_class_key gpio_lock_class;
+static struct lock_class_key gpio_request_class;
 
 static int bcm_kona_gpio_irq_map(struct irq_domain *d, unsigned int irq,
 				 irq_hw_number_t hwirq)
···
 	ret = irq_set_chip_data(irq, d->host_data);
 	if (ret < 0)
 		return ret;
-	irq_set_lockdep_class(irq, &gpio_lock_class);
+	irq_set_lockdep_class(irq, &gpio_lock_class, &gpio_request_class);
 	irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip, handle_simple_irq);
 	irq_set_noprobe(irq);
 

drivers/gpio/gpio-brcmstb.c

···
  * category than their parents, so it won't report false recursion.
  */
 static struct lock_class_key brcmstb_gpio_irq_lock_class;
+static struct lock_class_key brcmstb_gpio_irq_request_class;
 
 
 static int brcmstb_gpio_irq_map(struct irq_domain *d, unsigned int irq,
···
 	ret = irq_set_chip_data(irq, &bank->gc);
 	if (ret < 0)
 		return ret;
-	irq_set_lockdep_class(irq, &brcmstb_gpio_irq_lock_class);
+	irq_set_lockdep_class(irq, &brcmstb_gpio_irq_lock_class,
+			      &brcmstb_gpio_irq_lock_class);
 	irq_set_chip_and_handler(irq, &priv->irq_chip, handle_level_irq);
 	irq_set_noprobe(irq);
 	return 0;

drivers/gpio/gpio-tegra.c

···
  * than their parents, so it won't report false recursion.
  */
 static struct lock_class_key gpio_lock_class;
+static struct lock_class_key gpio_request_class;
 
 static int tegra_gpio_probe(struct platform_device *pdev)
 {
···
 
 		bank = &tgi->bank_info[GPIO_BANK(gpio)];
 
-		irq_set_lockdep_class(irq, &gpio_lock_class);
+		irq_set_lockdep_class(irq, &gpio_lock_class,
+				      &gpio_request_class);
 		irq_set_chip_data(irq, bank);
 		irq_set_chip_and_handler(irq, &tgi->ic, handle_simple_irq);
 	}

drivers/gpio/gpiolib.c

···
 
 static void gpiochip_free_hogs(struct gpio_chip *chip);
 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
-				struct lock_class_key *key);
+				struct lock_class_key *lock_key,
+				struct lock_class_key *request_key);
 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
···
 }
 
 int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
-			       struct lock_class_key *key)
+			       struct lock_class_key *lock_key,
+			       struct lock_class_key *request_key)
 {
 	unsigned long	flags;
 	int		status = 0;
···
 	if (status)
 		goto err_remove_from_list;
 
-	status = gpiochip_add_irqchip(chip, key);
+	status = gpiochip_add_irqchip(chip, lock_key, request_key);
 	if (status)
 		goto err_remove_chip;
 
···
 	 * This lock class tells lockdep that GPIO irqs are in a different
 	 * category than their parents, so it won't report false recursion.
 	 */
-	irq_set_lockdep_class(irq, chip->irq.lock_key);
+	irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
 	irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
 	/* Chips that use nested thread handlers have them marked */
 	if (chip->irq.threaded)
···
 /**
  * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
  * @gpiochip: the GPIO chip to add the IRQ chip to
- * @lock_key: lockdep class
+ * @lock_key: lockdep class for IRQ lock
+ * @request_key: lockdep class for IRQ request
  */
 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
-				struct lock_class_key *lock_key)
+				struct lock_class_key *lock_key,
+				struct lock_class_key *request_key)
 {
 	struct irq_chip *irqchip = gpiochip->irq.chip;
 	const struct irq_domain_ops *ops;
···
 	gpiochip->to_irq = gpiochip_to_irq;
 	gpiochip->irq.default_type = type;
 	gpiochip->irq.lock_key = lock_key;
+	gpiochip->irq.request_key = request_key;
 
 	if (gpiochip->irq.domain_ops)
 		ops = gpiochip->irq.domain_ops;
···
  * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
  * to have the core avoid setting up any default type in the hardware.
  * @threaded: whether this irqchip uses a nested thread handler
- * @lock_key: lockdep class
+ * @lock_key: lockdep class for IRQ lock
+ * @request_key: lockdep class for IRQ request
  *
  * This function closely associates a certain irqchip with a certain
  * gpiochip, providing an irq domain to translate the local IRQs to
···
 			     irq_flow_handler_t handler,
 			     unsigned int type,
 			     bool threaded,
-			     struct lock_class_key *lock_key)
+			     struct lock_class_key *lock_key,
+			     struct lock_class_key *request_key)
 {
 	struct device_node *of_node;
 
···
 	gpiochip->irq.default_type = type;
 	gpiochip->to_irq = gpiochip_to_irq;
 	gpiochip->irq.lock_key = lock_key;
+	gpiochip->irq.request_key = request_key;
 	gpiochip->irq.domain = irq_domain_add_simple(of_node,
 					gpiochip->ngpio, first_irq,
 					&gpiochip_domain_ops, gpiochip);
···
 #else /* CONFIG_GPIOLIB_IRQCHIP */
 
 static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
-				       struct lock_class_key *key)
+				       struct lock_class_key *lock_key,
+				       struct lock_class_key *request_key)
 {
 	return 0;
 }

drivers/irqchip/irq-renesas-intc-irqpin.c

···
  */
 static struct lock_class_key intc_irqpin_irq_lock_class;
 
+/* And this is for the request mutex */
+static struct lock_class_key intc_irqpin_irq_request_class;
+
 static int intc_irqpin_irq_domain_map(struct irq_domain *h, unsigned int virq,
 				      irq_hw_number_t hw)
 {
···
 
 	intc_irqpin_dbg(&p->irq[hw], "map");
 	irq_set_chip_data(virq, h->host_data);
-	irq_set_lockdep_class(virq, &intc_irqpin_irq_lock_class);
+	irq_set_lockdep_class(virq, &intc_irqpin_irq_lock_class,
+			      &intc_irqpin_irq_request_class);
 	irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
 	return 0;
 }

drivers/mfd/arizona-irq.c

···
 };
 
 static struct lock_class_key arizona_irq_lock_class;
+static struct lock_class_key arizona_irq_request_class;
 
 static int arizona_irq_map(struct irq_domain *h, unsigned int virq,
 			      irq_hw_number_t hw)
···
 	struct arizona *data = h->host_data;
 
 	irq_set_chip_data(virq, data);
-	irq_set_lockdep_class(virq, &arizona_irq_lock_class);
+	irq_set_lockdep_class(virq, &arizona_irq_lock_class,
+		&arizona_irq_request_class);
 	irq_set_chip_and_handler(virq, &arizona_irq_chip, handle_simple_irq);
 	irq_set_nested_thread(virq, 1);
 	irq_set_noprobe(virq);

drivers/pinctrl/pinctrl-single.c

···
  */
 static struct lock_class_key pcs_lock_class;
 
+/* Class for the IRQ request mutex */
+static struct lock_class_key pcs_request_class;
+
 /*
  * REVISIT: Reads and writes could eventually use regmap or something
  * generic. But at least on omaps, some mux registers are performance
···
 	irq_set_chip_data(irq, pcs_soc);
 	irq_set_chip_and_handler(irq, &pcs->chip,
 				 handle_level_irq);
-	irq_set_lockdep_class(irq, &pcs_lock_class);
+	irq_set_lockdep_class(irq, &pcs_lock_class, &pcs_request_class);
 	irq_set_noprobe(irq);
 
 	return 0;

include/linux/gpio/driver.h

···
 	/**
 	 * @lock_key:
 	 *
-	 * Per GPIO IRQ chip lockdep class.
+	 * Per GPIO IRQ chip lockdep classes.
 	 */
 	struct lock_class_key *lock_key;
+	struct lock_class_key *request_key;
 
 	/**
 	 * @parent_handler:
···
 
 /* add/remove chips */
 extern int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
-				      struct lock_class_key *lock_key);
+				      struct lock_class_key *lock_key,
+				      struct lock_class_key *request_key);
 
 /**
  * gpiochip_add_data() - register a gpio_chip
···
  */
 #ifdef CONFIG_LOCKDEP
 #define gpiochip_add_data(chip, data) ({		\
-		static struct lock_class_key key;	\
-		gpiochip_add_data_with_key(chip, data, &key);	\
+		static struct lock_class_key lock_key;	\
+		static struct lock_class_key request_key;	  \
+		gpiochip_add_data_with_key(chip, data, &lock_key, \
+					   &request_key);	  \
 	})
 #else
-#define gpiochip_add_data(chip, data) gpiochip_add_data_with_key(chip, data, NULL)
+#define gpiochip_add_data(chip, data) gpiochip_add_data_with_key(chip, data, NULL, NULL)
 #endif
 
 static inline int gpiochip_add(struct gpio_chip *chip)
···
 			     irq_flow_handler_t handler,
 			     unsigned int type,
 			     bool threaded,
-			     struct lock_class_key *lock_key);
+			     struct lock_class_key *lock_key,
+			     struct lock_class_key *request_key);
 
 #ifdef CONFIG_LOCKDEP
 
···
 				       irq_flow_handler_t handler,
 				       unsigned int type)
 {
-	static struct lock_class_key key;
+	static struct lock_class_key lock_key;
+	static struct lock_class_key request_key;
 
 	return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
-					handler, type, false, &key);
+					handler, type, false,
+					&lock_key, &request_key);
 }
 
 static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
···
 			  unsigned int type)
 {
 
-	static struct lock_class_key key;
+	static struct lock_class_key lock_key;
+	static struct lock_class_key request_key;
 
 	return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
-					handler, type, true, &key);
+					handler, type, true,
+					&lock_key, &request_key);
 }
 #else
 static inline int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
···
 				       unsigned int type)
 {
 	return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
-					handler, type, false, NULL);
+					handler, type, false, NULL, NULL);
 }
 
 static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
···
 			  unsigned int type)
 {
 	return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
-					handler, type, true, NULL);
+					handler, type, true, NULL, NULL);
 }
 #endif /* CONFIG_LOCKDEP */
 

include/linux/irqdesc.h

···
 }
 
 static inline void
-irq_set_lockdep_class(unsigned int irq, struct lock_class_key *class)
+irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
+		      struct lock_class_key *request_class)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
-	if (desc)
-		lockdep_set_class(&desc->lock, class);
+	if (desc) {
+		lockdep_set_class(&desc->lock, lock_class);
+		lockdep_set_class(&desc->request_mutex, request_class);
+	}
 }
 
 #ifdef CONFIG_IRQ_PREFLOW_FASTEOI

kernel/irq/generic-chip.c

···
 EXPORT_SYMBOL_GPL(irq_get_domain_generic_chip);
 
 /*
- * Separate lockdep class for interrupt chip which can nest irq_desc
- * lock.
+ * Separate lockdep classes for interrupt chip which can nest irq_desc
+ * lock and request mutex.
  */
 static struct lock_class_key irq_nested_lock_class;
+static struct lock_class_key irq_nested_request_class;
 
 /*
  * irq_map_generic_chip - Map a generic chip for an irq domain
···
 	set_bit(idx, &gc->installed);
 
 	if (dgc->gc_flags & IRQ_GC_INIT_NESTED_LOCK)
-		irq_set_lockdep_class(virq, &irq_nested_lock_class);
+		irq_set_lockdep_class(virq, &irq_nested_lock_class,
+				      &irq_nested_request_class);
 
 	if (chip->irq_calc_mask)
 		chip->irq_calc_mask(data);
···
 			continue;
 
 		if (flags & IRQ_GC_INIT_NESTED_LOCK)
-			irq_set_lockdep_class(i, &irq_nested_lock_class);
+			irq_set_lockdep_class(i, &irq_nested_lock_class,
+					      &irq_nested_request_class);
 
 		if (!(flags & IRQ_GC_NO_MASK)) {
 			struct irq_data *d = irq_get_irq_data(i);