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
 27bool enable_posted_msi __ro_after_init;
 28
 29static int disable_irq_remap;
 30static struct irq_remap_ops *remap_ops;
 31
 32static void irq_remapping_restore_boot_irq_mode(void)
 33{
 34	/*
 35	 * With interrupt-remapping, for now we will use virtual wire A
 36	 * mode, as virtual wire B is little complex (need to configure
 37	 * both IOAPIC RTE as well as interrupt-remapping table entry).
 38	 * As this gets called during crash dump, keep this simple for
 39	 * now.
 40	 */
 41	if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config())
 42		disconnect_bsp_APIC(0);
 43}
 44
 45static void __init irq_remapping_modify_x86_ops(void)
 46{
 47	x86_apic_ops.restore = irq_remapping_restore_boot_irq_mode;
 48}
 49
 50static __init int setup_nointremap(char *str)
 51{
 52	disable_irq_remap = 1;
 53	return 0;
 54}
 55early_param("nointremap", setup_nointremap);
 56
 57static __init int setup_irqremap(char *str)
 58{
 59	if (!str)
 60		return -EINVAL;
 61
 62	while (*str) {
 63		if (!strncmp(str, "on", 2)) {
 64			disable_irq_remap = 0;
 65			disable_irq_post = 0;
 66		} else if (!strncmp(str, "off", 3)) {
 67			disable_irq_remap = 1;
 68			disable_irq_post = 1;
 69		} else if (!strncmp(str, "nosid", 5))
 70			disable_sourceid_checking = 1;
 71		else if (!strncmp(str, "no_x2apic_optout", 16))
 72			no_x2apic_optout = 1;
 73		else if (!strncmp(str, "nopost", 6))
 74			disable_irq_post = 1;
 75		else if (IS_ENABLED(CONFIG_X86_POSTED_MSI) && !strncmp(str, "posted_msi", 10))
 76			enable_posted_msi = true;
 77		str += strcspn(str, ",");
 78		while (*str == ',')
 79			str++;
 80	}
 81
 82	return 0;
 83}
 84early_param("intremap", setup_irqremap);
 85
 86void set_irq_remapping_broken(void)
 87{
 88	irq_remap_broken = 1;
 89}
 90
 91bool irq_remapping_cap(enum irq_remap_cap cap)
 92{
 93	if (!remap_ops || disable_irq_post)
 94		return false;
 95
 96	return (remap_ops->capability & (1 << cap));
 97}
 98EXPORT_SYMBOL_GPL(irq_remapping_cap);
 99
100int __init irq_remapping_prepare(void)
101{
102	if (disable_irq_remap)
103		return -ENOSYS;
104
105	if (IS_ENABLED(CONFIG_INTEL_IOMMU) &&
106	    intel_irq_remap_ops.prepare() == 0)
107		remap_ops = &intel_irq_remap_ops;
108	else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
109		 amd_iommu_irq_ops.prepare() == 0)
110		remap_ops = &amd_iommu_irq_ops;
111	else if (IS_ENABLED(CONFIG_HYPERV_IOMMU) &&
112		 hyperv_irq_remap_ops.prepare() == 0)
113		remap_ops = &hyperv_irq_remap_ops;
114	else
115		return -ENOSYS;
116
117	return 0;
118}
119
120int __init irq_remapping_enable(void)
121{
122	int ret;
123
124	if (!remap_ops->enable)
125		return -ENODEV;
126
127	ret = remap_ops->enable();
128
129	if (irq_remapping_enabled)
130		irq_remapping_modify_x86_ops();
131
132	return ret;
133}
134
135void irq_remapping_disable(void)
136{
137	if (irq_remapping_enabled && remap_ops->disable)
138		remap_ops->disable();
139}
140
141int irq_remapping_reenable(int mode)
142{
143	if (irq_remapping_enabled && remap_ops->reenable)
144		return remap_ops->reenable(mode);
145
146	return 0;
147}
148
149int __init irq_remap_enable_fault_handling(void)
150{
151	if (!irq_remapping_enabled)
152		return 0;
153
154	if (!remap_ops->enable_faulting)
155		return -ENODEV;
156
157	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "dmar:enable_fault_handling",
158			  remap_ops->enable_faulting, NULL);
159
160	return remap_ops->enable_faulting(smp_processor_id());
161}
162
163void panic_if_irq_remap(const char *msg)
164{
165	if (irq_remapping_enabled)
166		panic(msg);
167}