irqchip fixes for 5.14, take #1

- Fix a MIPS bug where irqdomain loopkups could occur in a context
   where RCU is not allowed
 
 - Fix a documentation bug for handle_domain_irq
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Merge tag 'irqchip-fixes-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip fixes from Marc Zyngier:

 - Fix a MIPS bug where irqdomain loopkups could occur in a context
   where RCU is not allowed

 - Fix a documentation bug for handle_domain_irq

arch/mips/include/asm/irq.h

@@ -57,6 +57,9 @@ asmlinkage void plat_irq_dispatch(void);
 
 extern void do_IRQ(unsigned int irq);
 
+struct irq_domain;
+extern void do_domain_IRQ(struct irq_domain *domain, unsigned int irq);
+
 extern void arch_init_irq(void);
 extern void spurious_interrupt(void);
 

arch/mips/kernel/irq.c

@@ -21,6 +21,7 @@
 #include <linux/kallsyms.h>
 #include <linux/kgdb.h>
 #include <linux/ftrace.h>
+#include <linux/irqdomain.h>
 
 #include <linux/atomic.h>
 #include <linux/uaccess.h>
@@ -107,3 +108,18 @@ void __irq_entry do_IRQ(unsigned int irq)
 	irq_exit();
 }
 
+#ifdef CONFIG_IRQ_DOMAIN
+void __irq_entry do_domain_IRQ(struct irq_domain *domain, unsigned int hwirq)
+{
+	struct irq_desc *desc;
+
+	irq_enter();
+	check_stack_overflow();
+
+	desc = irq_resolve_mapping(domain, hwirq);
+	if (likely(desc))
+		handle_irq_desc(desc);
+
+	irq_exit();
+}
+#endif

drivers/irqchip/irq-mips-cpu.c

@@ -127,7 +127,6 @@ static struct irq_chip mips_mt_cpu_irq_controller = {
 asmlinkage void __weak plat_irq_dispatch(void)
 {
 	unsigned long pending = read_c0_cause() & read_c0_status() & ST0_IM;
-	unsigned int virq;
 	int irq;
 
 	if (!pending) {
@@ -137,12 +136,15 @@ asmlinkage void __weak plat_irq_dispatch(void)
 
 	pending >>= CAUSEB_IP;
 	while (pending) {
+		struct irq_domain *d;
+
 		irq = fls(pending) - 1;
 		if (IS_ENABLED(CONFIG_GENERIC_IRQ_IPI) && irq < 2)
-			virq = irq_linear_revmap(ipi_domain, irq);
+			d = ipi_domain;
 		else
-			virq = irq_linear_revmap(irq_domain, irq);
-		do_IRQ(virq);
+			d = irq_domain;
+
+		do_domain_IRQ(d, irq);
 		pending &= ~BIT(irq);
 	}
 }

drivers/irqchip/irq-mips-gic.c

@@ -169,8 +169,8 @@ static void gic_handle_shared_int(bool chained)
 			generic_handle_domain_irq(gic_irq_domain,
 						  GIC_SHARED_TO_HWIRQ(intr));
 		else
-			do_IRQ(irq_find_mapping(gic_irq_domain,
-						GIC_SHARED_TO_HWIRQ(intr)));
+			do_domain_IRQ(gic_irq_domain,
+				      GIC_SHARED_TO_HWIRQ(intr));
 	}
 }
 
@@ -320,8 +320,8 @@ static void gic_handle_local_int(bool chained)
 			generic_handle_domain_irq(gic_irq_domain,
 						  GIC_LOCAL_TO_HWIRQ(intr));
 		else
-			do_IRQ(irq_find_mapping(gic_irq_domain,
-						GIC_LOCAL_TO_HWIRQ(intr)));
+			do_domain_IRQ(gic_irq_domain,
+				      GIC_LOCAL_TO_HWIRQ(intr));
 	}
 }
 

drivers/irqchip/irq-pic32-evic.c

@@ -42,11 +42,10 @@ static void __iomem *evic_base;
 
 asmlinkage void __weak plat_irq_dispatch(void)
 {
-	unsigned int irq, hwirq;
+	unsigned int hwirq;
 
 	hwirq = readl(evic_base + REG_INTSTAT) & 0xFF;
-	irq = irq_linear_revmap(evic_irq_domain, hwirq);
-	do_IRQ(irq);
+	do_domain_IRQ(evic_irq_domain, hwirq);
 }
 
 static struct evic_chip_data *irqd_to_priv(struct irq_data *data)

kernel/irq/irqdesc.c

@@ -682,7 +682,6 @@ EXPORT_SYMBOL_GPL(generic_handle_domain_irq);
  *                     usually for a root interrupt controller
  * @domain:	The domain where to perform the lookup
  * @hwirq:	The HW irq number to convert to a logical one
- * @lookup:	Whether to perform the domain lookup or not
  * @regs:	Register file coming from the low-level handling code
  *
  * Returns:	0 on success, or -EINVAL if conversion has failed