cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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irq_64.c (2015B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 *	Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
      4 *
      5 * This file contains the lowest level x86_64-specific interrupt
      6 * entry and irq statistics code. All the remaining irq logic is
      7 * done by the generic kernel/irq/ code and in the
      8 * x86_64-specific irq controller code. (e.g. i8259.c and
      9 * io_apic.c.)
     10 */
     11
     12#include <linux/kernel_stat.h>
     13#include <linux/interrupt.h>
     14#include <linux/irq.h>
     15#include <linux/seq_file.h>
     16#include <linux/delay.h>
     17#include <linux/ftrace.h>
     18#include <linux/uaccess.h>
     19#include <linux/smp.h>
     20#include <linux/sched/task_stack.h>
     21
     22#include <asm/cpu_entry_area.h>
     23#include <asm/softirq_stack.h>
     24#include <asm/irq_stack.h>
     25#include <asm/io_apic.h>
     26#include <asm/apic.h>
     27
     28DEFINE_PER_CPU_PAGE_ALIGNED(struct irq_stack, irq_stack_backing_store) __visible;
     29DECLARE_INIT_PER_CPU(irq_stack_backing_store);
     30
     31#ifdef CONFIG_VMAP_STACK
     32/*
     33 * VMAP the backing store with guard pages
     34 */
     35static int map_irq_stack(unsigned int cpu)
     36{
     37	char *stack = (char *)per_cpu_ptr(&irq_stack_backing_store, cpu);
     38	struct page *pages[IRQ_STACK_SIZE / PAGE_SIZE];
     39	void *va;
     40	int i;
     41
     42	for (i = 0; i < IRQ_STACK_SIZE / PAGE_SIZE; i++) {
     43		phys_addr_t pa = per_cpu_ptr_to_phys(stack + (i << PAGE_SHIFT));
     44
     45		pages[i] = pfn_to_page(pa >> PAGE_SHIFT);
     46	}
     47
     48	va = vmap(pages, IRQ_STACK_SIZE / PAGE_SIZE, VM_MAP, PAGE_KERNEL);
     49	if (!va)
     50		return -ENOMEM;
     51
     52	/* Store actual TOS to avoid adjustment in the hotpath */
     53	per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE - 8;
     54	return 0;
     55}
     56#else
     57/*
     58 * If VMAP stacks are disabled due to KASAN, just use the per cpu
     59 * backing store without guard pages.
     60 */
     61static int map_irq_stack(unsigned int cpu)
     62{
     63	void *va = per_cpu_ptr(&irq_stack_backing_store, cpu);
     64
     65	/* Store actual TOS to avoid adjustment in the hotpath */
     66	per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE - 8;
     67	return 0;
     68}
     69#endif
     70
     71int irq_init_percpu_irqstack(unsigned int cpu)
     72{
     73	if (per_cpu(hardirq_stack_ptr, cpu))
     74		return 0;
     75	return map_irq_stack(cpu);
     76}