linux-stable/arch/x86/kernel/irq_64.c
Thomas Gleixner eb6555c839 x86/entry/64: Move do_softirq_own_stack() to C
The first step to get rid of the ENTER/LEAVE_IRQ_STACK ASM macro maze.  Use
the new C code helpers to move do_softirq_own_stack() out of ASM code.

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/20200521202117.870911120@linutronix.de
2020-06-11 15:15:07 +02:00

78 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
*
* This file contains the lowest level x86_64-specific interrupt
* entry and irq statistics code. All the remaining irq logic is
* done by the generic kernel/irq/ code and in the
* x86_64-specific irq controller code. (e.g. i8259.c and
* io_apic.c.)
*/
#include <linux/kernel_stat.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/seq_file.h>
#include <linux/delay.h>
#include <linux/ftrace.h>
#include <linux/uaccess.h>
#include <linux/smp.h>
#include <linux/sched/task_stack.h>
#include <asm/cpu_entry_area.h>
#include <asm/irq_stack.h>
#include <asm/io_apic.h>
#include <asm/apic.h>
DEFINE_PER_CPU_PAGE_ALIGNED(struct irq_stack, irq_stack_backing_store) __visible;
DECLARE_INIT_PER_CPU(irq_stack_backing_store);
#ifdef CONFIG_VMAP_STACK
/*
* VMAP the backing store with guard pages
*/
static int map_irq_stack(unsigned int cpu)
{
char *stack = (char *)per_cpu_ptr(&irq_stack_backing_store, cpu);
struct page *pages[IRQ_STACK_SIZE / PAGE_SIZE];
void *va;
int i;
for (i = 0; i < IRQ_STACK_SIZE / PAGE_SIZE; i++) {
phys_addr_t pa = per_cpu_ptr_to_phys(stack + (i << PAGE_SHIFT));
pages[i] = pfn_to_page(pa >> PAGE_SHIFT);
}
va = vmap(pages, IRQ_STACK_SIZE / PAGE_SIZE, VM_MAP, PAGE_KERNEL);
if (!va)
return -ENOMEM;
per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE;
return 0;
}
#else
/*
* If VMAP stacks are disabled due to KASAN, just use the per cpu
* backing store without guard pages.
*/
static int map_irq_stack(unsigned int cpu)
{
void *va = per_cpu_ptr(&irq_stack_backing_store, cpu);
per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE;
return 0;
}
#endif
int irq_init_percpu_irqstack(unsigned int cpu)
{
if (per_cpu(hardirq_stack_ptr, cpu))
return 0;
return map_irq_stack(cpu);
}
void do_softirq_own_stack(void)
{
run_on_irqstack_cond(__do_softirq, NULL, NULL);
}