[patch V9 22/39] x86/irq: Rework handle_irq() for 64bit

From: Thomas Gleixner
Date: Thu May 21 2020 - 16:33:35 EST


From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

To consolidate the interrupt entry/exit code vs. the other exceptions
make handle_irq() and inline and handle both 64bit and 32bit

Preparatory change to move irq stack switching for 64bit to C which allows
to consolidate the entry exit handling by reusing the idtentry machinery
both in ASM and C.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
V9: Adopt to inlined run_cond_on_irqstack()
---
arch/x86/include/asm/irq.h | 2 +-
arch/x86/kernel/irq.c | 11 ++++++++++-
arch/x86/kernel/irq_32.c | 2 +-
3 files changed, 12 insertions(+), 3 deletions(-)

--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -34,7 +34,7 @@ extern __visible void smp_kvm_posted_int
extern void (*x86_platform_ipi_callback)(void);
extern void native_init_IRQ(void);

-extern void handle_irq(struct irq_desc *desc, struct pt_regs *regs);
+extern void __handle_irq(struct irq_desc *desc, struct pt_regs *regs);

extern __visible void do_IRQ(struct pt_regs *regs, unsigned long vector);

--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -13,6 +13,7 @@
#include <linux/export.h>
#include <linux/irq.h>

+#include <asm/irq_stack.h>
#include <asm/apic.h>
#include <asm/io_apic.h>
#include <asm/irq.h>
@@ -221,6 +222,14 @@ u64 arch_irq_stat(void)
return sum;
}

+static __always_inline void handle_irq(struct irq_desc *desc,
+ struct pt_regs *regs)
+{
+ if (IS_ENABLED(CONFIG_X86_64))
+ run_on_irqstack_cond(desc->handle_irq, desc, regs);
+ else
+ __handle_irq(desc, regs);
+}

/*
* do_IRQ handles all normal device IRQ's (the special
@@ -246,7 +255,7 @@ u64 arch_irq_stat(void)
desc = __this_cpu_read(vector_irq[vector]);
if (likely(!IS_ERR_OR_NULL(desc))) {
if (IS_ENABLED(CONFIG_X86_32))
- handle_irq(desc, regs);
+ __handle_irq(desc, regs);
else
generic_handle_irq_desc(desc);
} else {
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -148,7 +148,7 @@ void do_softirq_own_stack(void)
call_on_stack(__do_softirq, isp);
}

-void 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();