1#include <linux/seq_file.h>
  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_disable_io_apic(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_io_apic_ops.disable		= irq_remapping_disable_io_apic;
 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
108		return -ENOSYS;
109
110	return 0;
111}
112
113int __init irq_remapping_enable(void)
114{
115	int ret;
116
117	if (!remap_ops->enable)
118		return -ENODEV;
119
120	ret = remap_ops->enable();
121
122	if (irq_remapping_enabled)
123		irq_remapping_modify_x86_ops();
124
125	return ret;
126}
127
128void irq_remapping_disable(void)
129{
130	if (irq_remapping_enabled && remap_ops->disable)
131		remap_ops->disable();
132}
133
134int irq_remapping_reenable(int mode)
135{
136	if (irq_remapping_enabled && remap_ops->reenable)
137		return remap_ops->reenable(mode);
138
139	return 0;
140}
141
142int __init irq_remap_enable_fault_handling(void)
143{
144	if (!irq_remapping_enabled)
145		return 0;
146
147	if (!remap_ops->enable_faulting)
148		return -ENODEV;
149
150	return remap_ops->enable_faulting();
151}
152
153void panic_if_irq_remap(const char *msg)
154{
155	if (irq_remapping_enabled)
156		panic(msg);
157}
158
159void ir_ack_apic_edge(struct irq_data *data)
160{
161	ack_APIC_irq();
162}
163
164/**
165 * irq_remapping_get_ir_irq_domain - Get the irqdomain associated with the IOMMU
166 *				     device serving request @info
167 * @info: interrupt allocation information, used to identify the IOMMU device
168 *
169 * It's used to get parent irqdomain for HPET and IOAPIC irqdomains.
170 * Returns pointer to IRQ domain, or NULL on failure.
171 */
172struct irq_domain *
173irq_remapping_get_ir_irq_domain(struct irq_alloc_info *info)
174{
175	if (!remap_ops || !remap_ops->get_ir_irq_domain)
176		return NULL;
177
178	return remap_ops->get_ir_irq_domain(info);
179}
180
181/**
182 * irq_remapping_get_irq_domain - Get the irqdomain serving the request @info
183 * @info: interrupt allocation information, used to identify the IOMMU device
184 *
185 * There will be one PCI MSI/MSIX irqdomain associated with each interrupt
186 * remapping device, so this interface is used to retrieve the PCI MSI/MSIX
187 * irqdomain serving request @info.
188 * Returns pointer to IRQ domain, or NULL on failure.
189 */
190struct irq_domain *
191irq_remapping_get_irq_domain(struct irq_alloc_info *info)
192{
193	if (!remap_ops || !remap_ops->get_irq_domain)
194		return NULL;
195
196	return remap_ops->get_irq_domain(info);
197}