linux/arch/x86/include/asm/irq.h
Thomas Gleixner 633260fa14 x86/irq: Convey vector as argument and not in ptregs
Device interrupts which go through do_IRQ() or the spurious interrupt
handler have their separate entry code on 64 bit for no good reason.

Both 32 and 64 bit transport the vector number through ORIG_[RE]AX in
pt_regs. Further the vector number is forced to fit into an u8 and is
complemented and offset by 0x80 so it's in the signed character
range. Otherwise GAS would expand the pushq to a 5 byte instruction for any
vector > 0x7F.

Treat the vector number like an error code and hand it to the C function as
argument. This allows to get rid of the extra entry code in a later step.

Simplify the error code push magic by implementing the pushq imm8 via a
'.byte 0x6a, vector' sequence so GAS is not able to screw it up. As the
pushq imm8 is sign extending the resulting error code needs to be truncated
to 8 bits in C code.

Originally-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200521202118.796915981@linutronix.de
2020-06-11 15:15:11 +02:00

54 lines
1.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_IRQ_H
#define _ASM_X86_IRQ_H
/*
* (C) 1992, 1993 Linus Torvalds, (C) 1997 Ingo Molnar
*
* IRQ/IPI changes taken from work by Thomas Radke
* <tomsoft@informatik.tu-chemnitz.de>
*/
#include <asm/apicdef.h>
#include <asm/irq_vectors.h>
static inline int irq_canonicalize(int irq)
{
return ((irq == 2) ? 9 : irq);
}
extern int irq_init_percpu_irqstack(unsigned int cpu);
#define __ARCH_HAS_DO_SOFTIRQ
struct irq_desc;
extern void fixup_irqs(void);
#ifdef CONFIG_HAVE_KVM
extern void kvm_set_posted_intr_wakeup_handler(void (*handler)(void));
extern __visible void smp_kvm_posted_intr_ipi(struct pt_regs *regs);
extern __visible void smp_kvm_posted_intr_wakeup_ipi(struct pt_regs *regs);
extern __visible void smp_kvm_posted_intr_nested_ipi(struct pt_regs *regs);
#endif
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 __visible void do_IRQ(struct pt_regs *regs, unsigned long vector);
extern void init_ISA_irqs(void);
extern void __init init_IRQ(void);
#ifdef CONFIG_X86_LOCAL_APIC
void arch_trigger_cpumask_backtrace(const struct cpumask *mask,
bool exclude_self);
extern __visible void smp_x86_platform_ipi(struct pt_regs *regs);
#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
#endif
#endif /* _ASM_X86_IRQ_H */