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 (IS_ENABLED(CONFIG_INTEL_IOMMU) &&
103	    intel_irq_remap_ops.prepare() == 0)
104		remap_ops = &intel_irq_remap_ops;
105	else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
106		 amd_iommu_irq_ops.prepare() == 0)
107		remap_ops = &amd_iommu_irq_ops;
108	else if (IS_ENABLED(CONFIG_HYPERV_IOMMU) &&
109		 hyperv_irq_remap_ops.prepare() == 0)
110		remap_ops = &hyperv_irq_remap_ops;
111	else
112		return -ENOSYS;
113
114	return 0;
115}
116
117int __init irq_remapping_enable(void)
118{
119	int ret;
120
121	if (!remap_ops->enable)
122		return -ENODEV;
123
124	ret = remap_ops->enable();
125
126	if (irq_remapping_enabled)
127		irq_remapping_modify_x86_ops();
128
129	return ret;
130}
131
132void irq_remapping_disable(void)
133{
134	if (irq_remapping_enabled && remap_ops->disable)
135		remap_ops->disable();
136}
137
138int irq_remapping_reenable(int mode)
139{
140	if (irq_remapping_enabled && remap_ops->reenable)
141		return remap_ops->reenable(mode);
142
143	return 0;
144}
145
146int __init irq_remap_enable_fault_handling(void)
147{
148	if (!irq_remapping_enabled)
149		return 0;
150
151	if (!remap_ops->enable_faulting)
152		return -ENODEV;
153
154	return remap_ops->enable_faulting();
155}
156
157void panic_if_irq_remap(const char *msg)
158{
159	if (irq_remapping_enabled)
160		panic(msg);
161}