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_remapping.c (3320B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2#include <linux/cpumask.h>
      3#include <linux/kernel.h>
      4#include <linux/string.h>
      5#include <linux/errno.h>
      6#include <linux/msi.h>
      7#include <linux/irq.h>
      8#include <linux/pci.h>
      9#include <linux/irqdomain.h>
     10
     11#include <asm/hw_irq.h>
     12#include <asm/irq_remapping.h>
     13#include <asm/processor.h>
     14#include <asm/x86_init.h>
     15#include <asm/apic.h>
     16#include <asm/hpet.h>
     17
     18#include "irq_remapping.h"
     19
     20int irq_remapping_enabled;
     21int irq_remap_broken;
     22int disable_sourceid_checking;
     23int no_x2apic_optout;
     24
     25int disable_irq_post = 0;
     26
     27static int disable_irq_remap;
     28static struct irq_remap_ops *remap_ops;
     29
     30static void irq_remapping_restore_boot_irq_mode(void)
     31{
     32	/*
     33	 * With interrupt-remapping, for now we will use virtual wire A
     34	 * mode, as virtual wire B is little complex (need to configure
     35	 * both IOAPIC RTE as well as interrupt-remapping table entry).
     36	 * As this gets called during crash dump, keep this simple for
     37	 * now.
     38	 */
     39	if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config())
     40		disconnect_bsp_APIC(0);
     41}
     42
     43static void __init irq_remapping_modify_x86_ops(void)
     44{
     45	x86_apic_ops.restore = irq_remapping_restore_boot_irq_mode;
     46}
     47
     48static __init int setup_nointremap(char *str)
     49{
     50	disable_irq_remap = 1;
     51	return 0;
     52}
     53early_param("nointremap", setup_nointremap);
     54
     55static __init int setup_irqremap(char *str)
     56{
     57	if (!str)
     58		return -EINVAL;
     59
     60	while (*str) {
     61		if (!strncmp(str, "on", 2)) {
     62			disable_irq_remap = 0;
     63			disable_irq_post = 0;
     64		} else if (!strncmp(str, "off", 3)) {
     65			disable_irq_remap = 1;
     66			disable_irq_post = 1;
     67		} else if (!strncmp(str, "nosid", 5))
     68			disable_sourceid_checking = 1;
     69		else if (!strncmp(str, "no_x2apic_optout", 16))
     70			no_x2apic_optout = 1;
     71		else if (!strncmp(str, "nopost", 6))
     72			disable_irq_post = 1;
     73
     74		str += strcspn(str, ",");
     75		while (*str == ',')
     76			str++;
     77	}
     78
     79	return 0;
     80}
     81early_param("intremap", setup_irqremap);
     82
     83void set_irq_remapping_broken(void)
     84{
     85	irq_remap_broken = 1;
     86}
     87
     88bool irq_remapping_cap(enum irq_remap_cap cap)
     89{
     90	if (!remap_ops || disable_irq_post)
     91		return false;
     92
     93	return (remap_ops->capability & (1 << cap));
     94}
     95EXPORT_SYMBOL_GPL(irq_remapping_cap);
     96
     97int __init irq_remapping_prepare(void)
     98{
     99	if (disable_irq_remap)
    100		return -ENOSYS;
    101
    102	if (intel_irq_remap_ops.prepare() == 0)
    103		remap_ops = &intel_irq_remap_ops;
    104	else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
    105		 amd_iommu_irq_ops.prepare() == 0)
    106		remap_ops = &amd_iommu_irq_ops;
    107	else if (IS_ENABLED(CONFIG_HYPERV_IOMMU) &&
    108		 hyperv_irq_remap_ops.prepare() == 0)
    109		remap_ops = &hyperv_irq_remap_ops;
    110	else
    111		return -ENOSYS;
    112
    113	return 0;
    114}
    115
    116int __init irq_remapping_enable(void)
    117{
    118	int ret;
    119
    120	if (!remap_ops->enable)
    121		return -ENODEV;
    122
    123	ret = remap_ops->enable();
    124
    125	if (irq_remapping_enabled)
    126		irq_remapping_modify_x86_ops();
    127
    128	return ret;
    129}
    130
    131void irq_remapping_disable(void)
    132{
    133	if (irq_remapping_enabled && remap_ops->disable)
    134		remap_ops->disable();
    135}
    136
    137int irq_remapping_reenable(int mode)
    138{
    139	if (irq_remapping_enabled && remap_ops->reenable)
    140		return remap_ops->reenable(mode);
    141
    142	return 0;
    143}
    144
    145int __init irq_remap_enable_fault_handling(void)
    146{
    147	if (!irq_remapping_enabled)
    148		return 0;
    149
    150	if (!remap_ops->enable_faulting)
    151		return -ENODEV;
    152
    153	return remap_ops->enable_faulting();
    154}
    155
    156void panic_if_irq_remap(const char *msg)
    157{
    158	if (irq_remapping_enabled)
    159		panic(msg);
    160}