[tip: x86/entry] x86/irq: Rework handle_irq() for 64-bit

From: tip-bot2 for Thomas Gleixner
Date: Wed May 27 2020 - 04:13:41 EST


The following commit has been merged into the x86/entry branch of tip:

Commit-ID: 9fe3411558d31f9489cd58400b2f508a98dc13a5
Gitweb: https://git.kernel.org/tip/9fe3411558d31f9489cd58400b2f508a98dc13a5
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Thu, 21 May 2020 22:05:35 +02:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 26 May 2020 19:06:28 +02:00

x86/irq: Rework handle_irq() for 64-bit

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

Preparatory change to move irq stack switching for 64-bit 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>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200521202118.889972748@xxxxxxxxxxxxx
---
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(-)

diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index 74690a3..67aa1e2 100644
--- a/arch/x86/include/asm/irq.h
+++ b/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 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);

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index c766936..5495ea4 100644
--- 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 @@ __visible void __irq_entry do_IRQ(struct pt_regs *regs, unsigned long vector)
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 {
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index a759ca9..0b79efc 100644
--- 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();