1 files changed, 160 insertions, 0 deletions
diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
new file mode 100644
index 000000000..83314b9d8
--- /dev/null
+++ b/drivers/iommu/irq_remapping.c
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/cpumask.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/msi.h>
+#include <linux/irq.h>
+#include <linux/pci.h>
+#include <linux/irqdomain.h>
+
+#include <asm/hw_irq.h>
+#include <asm/irq_remapping.h>
+#include <asm/processor.h>
+#include <asm/x86_init.h>
+#include <asm/apic.h>
+#include <asm/hpet.h>
+
+#include "irq_remapping.h"
+
+int irq_remapping_enabled;
+int irq_remap_broken;
+int disable_sourceid_checking;
+int no_x2apic_optout;
+
+int disable_irq_post = 0;
+
+static int disable_irq_remap;
+static struct irq_remap_ops *remap_ops;
+
+static void irq_remapping_restore_boot_irq_mode(void)
+{
+	/*
+	 * With interrupt-remapping, for now we will use virtual wire A
+	 * mode, as virtual wire B is little complex (need to configure
+	 * both IOAPIC RTE as well as interrupt-remapping table entry).
+	 * As this gets called during crash dump, keep this simple for
+	 * now.
+	 */
+	if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config())
+		disconnect_bsp_APIC(0);
+}
+
+static void __init irq_remapping_modify_x86_ops(void)
+{
+	x86_apic_ops.restore = irq_remapping_restore_boot_irq_mode;
+}
+
+static __init int setup_nointremap(char *str)
+{
+	disable_irq_remap = 1;
+	return 0;
+}
+early_param("nointremap", setup_nointremap);
+
+static __init int setup_irqremap(char *str)
+{
+	if (!str)
+		return -EINVAL;
+
+	while (*str) {
+		if (!strncmp(str, "on", 2)) {
+			disable_irq_remap = 0;
+			disable_irq_post = 0;
+		} else if (!strncmp(str, "off", 3)) {
+			disable_irq_remap = 1;
+			disable_irq_post = 1;
+		} else if (!strncmp(str, "nosid", 5))
+			disable_sourceid_checking = 1;
+		else if (!strncmp(str, "no_x2apic_optout", 16))
+			no_x2apic_optout = 1;
+		else if (!strncmp(str, "nopost", 6))
+			disable_irq_post = 1;
+
+		str += strcspn(str, ",");
+		while (*str == ',')
+			str++;
+	}
+
+	return 0;
+}
+early_param("intremap", setup_irqremap);
+
+void set_irq_remapping_broken(void)
+{
+	irq_remap_broken = 1;
+}
+
+bool irq_remapping_cap(enum irq_remap_cap cap)
+{
+	if (!remap_ops || disable_irq_post)
+		return false;
+
+	return (remap_ops->capability & (1 << cap));
+}
+EXPORT_SYMBOL_GPL(irq_remapping_cap);
+
+int __init irq_remapping_prepare(void)
+{
+	if (disable_irq_remap)
+		return -ENOSYS;
+
+	if (intel_irq_remap_ops.prepare() == 0)
+		remap_ops = &intel_irq_remap_ops;
+	else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
+		 amd_iommu_irq_ops.prepare() == 0)
+		remap_ops = &amd_iommu_irq_ops;
+	else if (IS_ENABLED(CONFIG_HYPERV_IOMMU) &&
+		 hyperv_irq_remap_ops.prepare() == 0)
+		remap_ops = &hyperv_irq_remap_ops;
+	else
+		return -ENOSYS;
+
+	return 0;
+}
+
+int __init irq_remapping_enable(void)
+{
+	int ret;
+
+	if (!remap_ops->enable)
+		return -ENODEV;
+
+	ret = remap_ops->enable();
+
+	if (irq_remapping_enabled)
+		irq_remapping_modify_x86_ops();
+
+	return ret;
+}
+
+void irq_remapping_disable(void)
+{
+	if (irq_remapping_enabled && remap_ops->disable)
+		remap_ops->disable();
+}
+
+int irq_remapping_reenable(int mode)
+{
+	if (irq_remapping_enabled && remap_ops->reenable)
+		return remap_ops->reenable(mode);
+
+	return 0;
+}
+
+int __init irq_remap_enable_fault_handling(void)
+{
+	if (!irq_remapping_enabled)
+		return 0;
+
+	if (!remap_ops->enable_faulting)
+		return -ENODEV;
+
+	return remap_ops->enable_faulting();
+}
+
+void panic_if_irq_remap(const char *msg)
+{
+	if (irq_remapping_enabled)
+		panic(msg);
+}