drivers/iommu/intel/irq_remapping.c

Source file repositories/reference/linux-study-clean/drivers/iommu/intel/irq_remapping.c

File Facts

System
Linux kernel
Corpus path
drivers/iommu/intel/irq_remapping.c
Extension
.c
Size
40938 bytes
Lines
1606
Domain
Driver Families
Bucket
drivers/iommu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct ioapic_scope {
	struct intel_iommu *iommu;
	unsigned int id;
	unsigned int bus;	/* PCI bus number */
	unsigned int devfn;	/* PCI devfn number */
};

struct hpet_scope {
	struct intel_iommu *iommu;
	u8 id;
	unsigned int bus;
	unsigned int devfn;
};

struct irq_2_iommu {
	struct intel_iommu *iommu;
	u16 irte_index;
	u16 sub_handle;
	u8  irte_mask;
	bool posted_msi;
	bool posted_vcpu;
};

struct intel_ir_data {
	struct irq_2_iommu			irq_2_iommu;
	struct irte				irte_entry;
	union {
		struct msi_msg			msi_entry;
	};
};

#define IR_X2APIC_MODE(mode) (mode ? (1 << 11) : 0)
#define IRTE_DEST(dest) ((eim_mode) ? dest : dest << 8)

static int __read_mostly eim_mode;
static struct ioapic_scope ir_ioapic[MAX_IO_APICS];
static struct hpet_scope ir_hpet[MAX_HPET_TBS];

/*
 * Lock ordering:
 * ->dmar_global_lock
 *	->irq_2_ir_lock
 *		->qi->q_lock
 *	->iommu->register_lock
 * Note:
 * intel_irq_remap_ops.{supported,prepare,enable,disable,reenable} are called
 * in single-threaded environment with interrupt disabled, so no need to tabke
 * the dmar_global_lock.
 */
DEFINE_RAW_SPINLOCK(irq_2_ir_lock);
static const struct irq_domain_ops intel_ir_domain_ops;

static void iommu_disable_irq_remapping(struct intel_iommu *iommu);
static int __init parse_ioapics_under_ir(void);
static const struct msi_parent_ops dmar_msi_parent_ops;

static bool ir_pre_enabled(struct intel_iommu *iommu)
{
	return (iommu->flags & VTD_FLAG_IRQ_REMAP_PRE_ENABLED);
}

static void clear_ir_pre_enabled(struct intel_iommu *iommu)
{
	iommu->flags &= ~VTD_FLAG_IRQ_REMAP_PRE_ENABLED;
}

static void init_ir_status(struct intel_iommu *iommu)
{
	u32 gsts;

	gsts = readl(iommu->reg + DMAR_GSTS_REG);
	if (gsts & DMA_GSTS_IRES)
		iommu->flags |= VTD_FLAG_IRQ_REMAP_PRE_ENABLED;
}

static int alloc_irte(struct intel_iommu *iommu,
		      struct irq_2_iommu *irq_iommu, u16 count)
{
	struct ir_table *table = iommu->ir_table;
	unsigned int mask = 0;
	unsigned long flags;
	int index;

	if (!count || !irq_iommu)
		return -1;

	if (count > 1) {
		count = __roundup_pow_of_two(count);
		mask = ilog2(count);
	}

Annotation

Implementation Notes