Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 interrupt updates from Thomas Gleixner:
 "A small set of changes to simplify and improve the interrupt handling
  in do_IRQ() by moving the common case into common code and thereby
  cleaning it up"

* 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/irq: Check for VECTOR_UNUSED directly
  x86/irq: Move IS_ERR_OR_NULL() check into common do_IRQ() code
  x86/irq: Improve definition of VECTOR_SHUTDOWN et al

Author: torvalds

arch/x86/include/asm/hw_irq.h

@@ -153,8 +153,8 @@ extern char irq_entries_start[];
 extern char spurious_entries_start[];
 
 #define VECTOR_UNUSED		NULL
-#define VECTOR_SHUTDOWN		((void *)~0UL)
-#define VECTOR_RETRIGGERED	((void *)~1UL)
+#define VECTOR_SHUTDOWN		((void *)-1L)
+#define VECTOR_RETRIGGERED	((void *)-2L)
 
 typedef struct irq_desc* vector_irq_t[NR_VECTORS];
 DECLARE_PER_CPU(vector_irq_t, vector_irq);

arch/x86/include/asm/irq.h

@@ -34,7 +34,7 @@ extern __visible void smp_kvm_posted_intr_nested_ipi(struct pt_regs *regs);
 extern void (*x86_platform_ipi_callback)(void);
 extern void native_init_IRQ(void);
 
-extern bool handle_irq(struct irq_desc *desc, struct pt_regs *regs);
+extern void handle_irq(struct irq_desc *desc, struct pt_regs *regs);
 
 extern __visible unsigned int do_IRQ(struct pt_regs *regs);
 

arch/x86/kernel/irq.c

@@ -243,11 +243,15 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 	RCU_LOCKDEP_WARN(!rcu_is_watching(), "IRQ failed to wake up RCU");
 
 	desc = __this_cpu_read(vector_irq[vector]);
-
-	if (!handle_irq(desc, regs)) {
+	if (likely(!IS_ERR_OR_NULL(desc))) {
+		if (IS_ENABLED(CONFIG_X86_32))
+			handle_irq(desc, regs);
+		else
+			generic_handle_irq_desc(desc);
+	} else {
 		ack_APIC_irq();
 
-		if (desc != VECTOR_RETRIGGERED && desc != VECTOR_SHUTDOWN) {
+		if (desc == VECTOR_UNUSED) {
 			pr_emerg_ratelimited("%s: %d.%d No irq handler for vector\n",
 					     __func__, smp_processor_id(),
 					     vector);

arch/x86/kernel/irq_32.c

@@ -148,18 +148,13 @@ void do_softirq_own_stack(void)
 	call_on_stack(__do_softirq, isp);
 }
 
-bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
+void handle_irq(struct irq_desc *desc, struct pt_regs *regs)
 {
 	int overflow = check_stack_overflow();
 
-	if (IS_ERR_OR_NULL(desc))
-		return false;
-
 	if (user_mode(regs) || !execute_on_irq_stack(overflow, desc)) {
 		if (unlikely(overflow))
 			print_stack_overflow();
 		generic_handle_irq_desc(desc);
 	}
-
-	return true;
 }

arch/x86/kernel/irq_64.c

@@ -26,15 +26,6 @@
 DEFINE_PER_CPU_PAGE_ALIGNED(struct irq_stack, irq_stack_backing_store) __visible;
 DECLARE_INIT_PER_CPU(irq_stack_backing_store);
 
-bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
-{
-	if (IS_ERR_OR_NULL(desc))
-		return false;
-
-	generic_handle_irq_desc(desc);
-	return true;
-}
-
 #ifdef CONFIG_VMAP_STACK
 /*
  * VMAP the backing store with guard pages