blob: 8b65a489581b07aa88349a1f37285f03efec6b2b [file] [log] [blame]
#include <linux/interrupt.h>
#include <linux/dmar.h>
#include <linux/spinlock.h>
#include <linux/jiffies.h>
#include <linux/hpet.h>
#include <linux/pci.h>
#include <linux/irq.h>
#include <asm/io_apic.h>
#include <asm/smp.h>
#include <asm/cpu.h>
#include <linux/intel-iommu.h>
#include "intr_remapping.h"
#include <acpi/acpi.h>
#include <asm/pci-direct.h>
#include "pci.h"
static struct ioapic_scope ir_ioapic[MAX_IO_APICS];
static struct hpet_scope ir_hpet[MAX_HPET_TBS];
static int ir_ioapic_num, ir_hpet_num;
int intr_remapping_enabled;
static int disable_intremap;
static __init int setup_nointremap(char *str)
{
disable_intremap = 1;
return 0;
}
early_param("nointremap", setup_nointremap);
struct irq_2_iommu {
struct intel_iommu *iommu;
u16 irte_index;
u16 sub_handle;
u8 irte_mask;
};
#ifdef CONFIG_GENERIC_HARDIRQS
static struct irq_2_iommu *get_one_free_irq_2_iommu(int node)
{
struct irq_2_iommu *iommu;
iommu = kzalloc_node(sizeof(*iommu), GFP_ATOMIC, node);
printk(KERN_DEBUG "alloc irq_2_iommu on node %d\n", node);
return iommu;
}
static struct irq_2_iommu *irq_2_iommu(unsigned int irq)
{
struct irq_desc *desc;
desc = irq_to_desc(irq);
if (WARN_ON_ONCE(!desc))
return NULL;
return desc->irq_2_iommu;
}
static struct irq_2_iommu *irq_2_iommu_alloc(unsigned int irq)
{
struct irq_desc *desc;
struct irq_2_iommu *irq_iommu;
desc = irq_to_desc(irq);
if (!desc) {
printk(KERN_INFO "can not get irq_desc for %d\n", irq);
return NULL;
}
irq_iommu = desc->irq_2_iommu;
if (!irq_iommu)
desc->irq_2_iommu = get_one_free_irq_2_iommu(irq_node(irq));
return desc->irq_2_iommu;
}
#else /* !CONFIG_SPARSE_IRQ */
static struct irq_2_iommu irq_2_iommuX[NR_IRQS];
static struct irq_2_iommu *irq_2_iommu(unsigned int irq)
{
if (irq < nr_irqs)
return &irq_2_iommuX[irq];
return NULL;
}
static struct irq_2_iommu *irq_2_iommu_alloc(unsigned int irq)
{
return irq_2_iommu(irq);
}
#endif
static DEFINE_SPINLOCK(irq_2_ir_lock);
static struct irq_2_iommu *valid_irq_2_iommu(unsigned int irq)
{
struct irq_2_iommu *irq_iommu;
irq_iommu = irq_2_iommu(irq);
if (!irq_iommu)
return NULL;
if (!irq_iommu->iommu)
return NULL;
return irq_iommu;
}
int irq_remapped(int irq)
{
return valid_irq_2_iommu(irq) != NULL;
}
int get_irte(int irq, struct irte *entry)
{
int index;
struct irq_2_iommu *irq_iommu;
unsigned long flags;
if (!entry)
return -1;
spin_lock_irqsave(&irq_2_ir_lock, flags);
irq_iommu = valid_irq_2_iommu(irq);
if (!irq_iommu) {
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return -1;
}
index = irq_iommu->irte_index + irq_iommu->sub_handle;
*entry = *(irq_iommu->iommu->ir_table->base + index);
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return 0;
}
int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
{
struct ir_table *table = iommu->ir_table;
struct irq_2_iommu *irq_iommu;
u16 index, start_index;
unsigned int mask = 0;
unsigned long flags;
int i;
if (!count)
return -1;
#ifndef CONFIG_SPARSE_IRQ
/* protect irq_2_iommu_alloc later */
if (irq >= nr_irqs)
return -1;
#endif
/*
* start the IRTE search from index 0.
*/
index = start_index = 0;
if (count > 1) {
count = __roundup_pow_of_two(count);
mask = ilog2(count);
}
if (mask > ecap_max_handle_mask(iommu->ecap)) {
printk(KERN_ERR
"Requested mask %x exceeds the max invalidation handle"
" mask value %Lx\n", mask,
ecap_max_handle_mask(iommu->ecap));
return -1;
}
spin_lock_irqsave(&irq_2_ir_lock, flags);
do {
for (i = index; i < index + count; i++)
if (table->base[i].present)
break;
/* empty index found */
if (i == index + count)
break;
index = (index + count) % INTR_REMAP_TABLE_ENTRIES;
if (index == start_index) {
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
printk(KERN_ERR "can't allocate an IRTE\n");
return -1;
}
} while (1);
for (i = index; i < index + count; i++)
table->base[i].present = 1;
irq_iommu = irq_2_iommu_alloc(irq);
if (!irq_iommu) {
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
printk(KERN_ERR "can't allocate irq_2_iommu\n");
return -1;
}
irq_iommu->iommu = iommu;
irq_iommu->irte_index = index;
irq_iommu->sub_handle = 0;
irq_iommu->irte_mask = mask;
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return index;
}
static int qi_flush_iec(struct intel_iommu *iommu, int index, int mask)
{
struct qi_desc desc;
desc.low = QI_IEC_IIDEX(index) | QI_IEC_TYPE | QI_IEC_IM(mask)
| QI_IEC_SELECTIVE;
desc.high = 0;
return qi_submit_sync(&desc, iommu);
}
int map_irq_to_irte_handle(int irq, u16 *sub_handle)
{
int index;
struct irq_2_iommu *irq_iommu;
unsigned long flags;
spin_lock_irqsave(&irq_2_ir_lock, flags);
irq_iommu = valid_irq_2_iommu(irq);
if (!irq_iommu) {
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return -1;
}
*sub_handle = irq_iommu->sub_handle;
index = irq_iommu->irte_index;
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return index;
}
int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, u16 subhandle)
{
struct irq_2_iommu *irq_iommu;
unsigned long flags;
spin_lock_irqsave(&irq_2_ir_lock, flags);
irq_iommu = irq_2_iommu_alloc(irq);
if (!irq_iommu) {
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
printk(KERN_ERR "can't allocate irq_2_iommu\n");
return -1;
}
irq_iommu->iommu = iommu;
irq_iommu->irte_index = index;
irq_iommu->sub_handle = subhandle;
irq_iommu->irte_mask = 0;
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return 0;
}
int clear_irte_irq(int irq, struct intel_iommu *iommu, u16 index)
{
struct irq_2_iommu *irq_iommu;
unsigned long flags;
spin_lock_irqsave(&irq_2_ir_lock, flags);
irq_iommu = valid_irq_2_iommu(irq);
if (!irq_iommu) {
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return -1;
}
irq_iommu->iommu = NULL;
irq_iommu->irte_index = 0;
irq_iommu->sub_handle = 0;
irq_2_iommu(irq)->irte_mask = 0;
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return 0;
}
int modify_irte(int irq, struct irte *irte_modified)
{
int rc;
int index;
struct irte *irte;
struct intel_iommu *iommu;
struct irq_2_iommu *irq_iommu;
unsigned long flags;
spin_lock_irqsave(&irq_2_ir_lock, flags);
irq_iommu = valid_irq_2_iommu(irq);
if (!irq_iommu) {
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return -1;
}
iommu = irq_iommu->iommu;
index = irq_iommu->irte_index + irq_iommu->sub_handle;
irte = &iommu->ir_table->base[index];
set_64bit((unsigned long *)&irte->low, irte_modified->low);
set_64bit((unsigned long *)&irte->high, irte_modified->high);
__iommu_flush_cache(iommu, irte, sizeof(*irte));
rc = qi_flush_iec(iommu, index, 0);
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return rc;
}
int flush_irte(int irq)
{
int rc;
int index;
struct intel_iommu *iommu;
struct irq_2_iommu *irq_iommu;
unsigned long flags;
spin_lock_irqsave(&irq_2_ir_lock, flags);
irq_iommu = valid_irq_2_iommu(irq);
if (!irq_iommu) {
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return -1;
}
iommu = irq_iommu->iommu;
index = irq_iommu->irte_index + irq_iommu->sub_handle;
rc = qi_flush_iec(iommu, index, irq_iommu->irte_mask);
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return rc;
}
struct intel_iommu *map_hpet_to_ir(u8 hpet_id)
{
int i;
for (i = 0; i < MAX_HPET_TBS; i++)
if (ir_hpet[i].id == hpet_id)
return ir_hpet[i].iommu;
return NULL;
}
struct intel_iommu *map_ioapic_to_ir(int apic)
{
int i;
for (i = 0; i < MAX_IO_APICS; i++)
if (ir_ioapic[i].id == apic)
return ir_ioapic[i].iommu;
return NULL;
}
struct intel_iommu *map_dev_to_ir(struct pci_dev *dev)
{
struct dmar_drhd_unit *drhd;
drhd = dmar_find_matched_drhd_unit(dev);
if (!drhd)
return NULL;
return drhd->iommu;
}
static int clear_entries(struct irq_2_iommu *irq_iommu)
{
struct irte *start, *entry, *end;
struct intel_iommu *iommu;
int index;
if (irq_iommu->sub_handle)
return 0;
iommu = irq_iommu->iommu;
index = irq_iommu->irte_index + irq_iommu->sub_handle;
start = iommu->ir_table->base + index;
end = start + (1 << irq_iommu->irte_mask);
for (entry = start; entry < end; entry++) {
set_64bit((unsigned long *)&entry->low, 0);
set_64bit((unsigned long *)&entry->high, 0);
}
return qi_flush_iec(iommu, index, irq_iommu->irte_mask);
}
int free_irte(int irq)
{
int rc = 0;
struct irq_2_iommu *irq_iommu;
unsigned long flags;
spin_lock_irqsave(&irq_2_ir_lock, flags);
irq_iommu = valid_irq_2_iommu(irq);
if (!irq_iommu) {
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return -1;
}
rc = clear_entries(irq_iommu);
irq_iommu->iommu = NULL;
irq_iommu->irte_index = 0;
irq_iommu->sub_handle = 0;
irq_iommu->irte_mask = 0;
spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return rc;
}
/*
* source validation type
*/
#define SVT_NO_VERIFY 0x0 /* no verification is required */
#define SVT_VERIFY_SID_SQ 0x1 /* verify using SID and SQ fiels */
#define SVT_VERIFY_BUS 0x2 /* verify bus of request-id */
/*
* source-id qualifier
*/
#define SQ_ALL_16 0x0 /* verify all 16 bits of request-id */
#define SQ_13_IGNORE_1 0x1 /* verify most significant 13 bits, ignore
* the third least significant bit
*/
#define SQ_13_IGNORE_2 0x2 /* verify most significant 13 bits, ignore
* the second and third least significant bits
*/
#define SQ_13_IGNORE_3 0x3 /* verify most significant 13 bits, ignore
* the least three significant bits
*/
/*
* set SVT, SQ and SID fields of irte to verify
* source ids of interrupt requests
*/
static void set_irte_sid(struct irte *irte, unsigned int svt,
unsigned int sq, unsigned int sid)
{
irte->svt = svt;
irte->sq = sq;
irte->sid = sid;
}
int set_ioapic_sid(struct irte *irte, int apic)
{
int i;
u16 sid = 0;
if (!irte)
return -1;
for (i = 0; i < MAX_IO_APICS; i++) {
if (ir_ioapic[i].id == apic) {
sid = (ir_ioapic[i].bus << 8) | ir_ioapic[i].devfn;
break;
}
}
if (sid == 0) {
pr_warning("Failed to set source-id of IOAPIC (%d)\n", apic);
return -1;
}
set_irte_sid(irte, 1, 0, sid);
return 0;
}
int set_hpet_sid(struct irte *irte, u8 id)
{
int i;
u16 sid = 0;
if (!irte)
return -1;
for (i = 0; i < MAX_HPET_TBS; i++) {
if (ir_hpet[i].id == id) {
sid = (ir_hpet[i].bus << 8) | ir_hpet[i].devfn;
break;
}
}
if (sid == 0) {
pr_warning("Failed to set source-id of HPET block (%d)\n", id);
return -1;
}
/*
* Should really use SQ_ALL_16. Some platforms are broken.
* While we figure out the right quirks for these broken platforms, use
* SQ_13_IGNORE_3 for now.
*/
set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_13_IGNORE_3, sid);
return 0;
}
int set_msi_sid(struct irte *irte, struct pci_dev *dev)
{
struct pci_dev *bridge;
if (!irte || !dev)
return -1;
/* PCIe device or Root Complex integrated PCI device */
if (pci_is_pcie(dev) || !dev->bus->parent) {
set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_ALL_16,
(dev->bus->number << 8) | dev->devfn);
return 0;
}
bridge = pci_find_upstream_pcie_bridge(dev);
if (bridge) {
if (pci_is_pcie(bridge))/* this is a PCIE-to-PCI/PCIX bridge */
set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16,
(bridge->bus->number << 8) | dev->bus->number);
else /* this is a legacy PCI bridge */
set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_ALL_16,
(bridge->bus->number << 8) | bridge->devfn);
}
return 0;
}
static void iommu_set_intr_remapping(struct intel_iommu *iommu, int mode)
{
u64 addr;
u32 sts;
unsigned long flags;
addr = virt_to_phys((void *)iommu->ir_table->base);
spin_lock_irqsave(&iommu->register_lock, flags);
dmar_writeq(iommu->reg + DMAR_IRTA_REG,
(addr) | IR_X2APIC_MODE(mode) | INTR_REMAP_TABLE_REG_SIZE);
/* Set interrupt-remapping table pointer */
iommu->gcmd |= DMA_GCMD_SIRTP;
writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
readl, (sts & DMA_GSTS_IRTPS), sts);
spin_unlock_irqrestore(&iommu->register_lock, flags);
/*
* global invalidation of interrupt entry cache before enabling
* interrupt-remapping.
*/
qi_global_iec(iommu);
spin_lock_irqsave(&iommu->register_lock, flags);
/* Enable interrupt-remapping */
iommu->gcmd |= DMA_GCMD_IRE;
writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
readl, (sts & DMA_GSTS_IRES), sts);
spin_unlock_irqrestore(&iommu->register_lock, flags);
}
static int setup_intr_remapping(struct intel_iommu *iommu, int mode)
{
struct ir_table *ir_table;
struct page *pages;
ir_table = iommu->ir_table = kzalloc(sizeof(struct ir_table),
GFP_ATOMIC);
if (!iommu->ir_table)
return -ENOMEM;
pages = alloc_pages_node(iommu->node, GFP_ATOMIC | __GFP_ZERO,
INTR_REMAP_PAGE_ORDER);
if (!pages) {
printk(KERN_ERR "failed to allocate pages of order %d\n",
INTR_REMAP_PAGE_ORDER);
kfree(iommu->ir_table);
return -ENOMEM;
}
ir_table->base = page_address(pages);
iommu_set_intr_remapping(iommu, mode);
return 0;
}
/*
* Disable Interrupt Remapping.
*/
static void iommu_disable_intr_remapping(struct intel_iommu *iommu)
{
unsigned long flags;
u32 sts;
if (!ecap_ir_support(iommu->ecap))
return;
/*
* global invalidation of interrupt entry cache before disabling
* interrupt-remapping.
*/
qi_global_iec(iommu);
spin_lock_irqsave(&iommu->register_lock, flags);
sts = dmar_readq(iommu->reg + DMAR_GSTS_REG);
if (!(sts & DMA_GSTS_IRES))
goto end;
iommu->gcmd &= ~DMA_GCMD_IRE;
writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
readl, !(sts & DMA_GSTS_IRES), sts);
end:
spin_unlock_irqrestore(&iommu->register_lock, flags);
}
int __init intr_remapping_supported(void)
{
struct dmar_drhd_unit *drhd;
if (disable_intremap)
return 0;
if (!dmar_ir_support())
return 0;
for_each_drhd_unit(drhd) {
struct intel_iommu *iommu = drhd->iommu;
if (!ecap_ir_support(iommu->ecap))
return 0;
}
return 1;
}
int __init enable_intr_remapping(int eim)
{
struct dmar_drhd_unit *drhd;
int setup = 0;
if (parse_ioapics_under_ir() != 1) {
printk(KERN_INFO "Not enable interrupt remapping\n");
return -1;
}
for_each_drhd_unit(drhd) {
struct intel_iommu *iommu = drhd->iommu;
/*
* If the queued invalidation is already initialized,
* shouldn't disable it.
*/
if (iommu->qi)
continue;
/*
* Clear previous faults.
*/
dmar_fault(-1, iommu);
/*
* Disable intr remapping and queued invalidation, if already
* enabled prior to OS handover.
*/
iommu_disable_intr_remapping(iommu);
dmar_disable_qi(iommu);
}
/*
* check for the Interrupt-remapping support
*/
for_each_drhd_unit(drhd) {
struct intel_iommu *iommu = drhd->iommu;
if (!ecap_ir_support(iommu->ecap))
continue;
if (eim && !ecap_eim_support(iommu->ecap)) {
printk(KERN_INFO "DRHD %Lx: EIM not supported by DRHD, "
" ecap %Lx\n", drhd->reg_base_addr, iommu->ecap);
return -1;
}
}
/*
* Enable queued invalidation for all the DRHD's.
*/
for_each_drhd_unit(drhd) {
int ret;
struct intel_iommu *iommu = drhd->iommu;
ret = dmar_enable_qi(iommu);
if (ret) {
printk(KERN_ERR "DRHD %Lx: failed to enable queued, "
" invalidation, ecap %Lx, ret %d\n",
drhd->reg_base_addr, iommu->ecap, ret);
return -1;
}
}
/*
* Setup Interrupt-remapping for all the DRHD's now.
*/
for_each_drhd_unit(drhd) {
struct intel_iommu *iommu = drhd->iommu;
if (!ecap_ir_support(iommu->ecap))
continue;
if (setup_intr_remapping(iommu, eim))
goto error;
setup = 1;
}
if (!setup)
goto error;
intr_remapping_enabled = 1;
return 0;
error:
/*
* handle error condition gracefully here!
*/
return -1;
}
static void ir_parse_one_hpet_scope(struct acpi_dmar_device_scope *scope,
struct intel_iommu *iommu)
{
struct acpi_dmar_pci_path *path;
u8 bus;
int count;
bus = scope->bus;
path = (struct acpi_dmar_pci_path *)(scope + 1);
count = (scope->length - sizeof(struct acpi_dmar_device_scope))
/ sizeof(struct acpi_dmar_pci_path);
while (--count > 0) {
/*
* Access PCI directly due to the PCI
* subsystem isn't initialized yet.
*/
bus = read_pci_config_byte(bus, path->dev, path->fn,
PCI_SECONDARY_BUS);
path++;
}
ir_hpet[ir_hpet_num].bus = bus;
ir_hpet[ir_hpet_num].devfn = PCI_DEVFN(path->dev, path->fn);
ir_hpet[ir_hpet_num].iommu = iommu;
ir_hpet[ir_hpet_num].id = scope->enumeration_id;
ir_hpet_num++;
}
static void ir_parse_one_ioapic_scope(struct acpi_dmar_device_scope *scope,
struct intel_iommu *iommu)
{
struct acpi_dmar_pci_path *path;
u8 bus;
int count;
bus = scope->bus;
path = (struct acpi_dmar_pci_path *)(scope + 1);
count = (scope->length - sizeof(struct acpi_dmar_device_scope))
/ sizeof(struct acpi_dmar_pci_path);
while (--count > 0) {
/*
* Access PCI directly due to the PCI
* subsystem isn't initialized yet.
*/
bus = read_pci_config_byte(bus, path->dev, path->fn,
PCI_SECONDARY_BUS);
path++;
}
ir_ioapic[ir_ioapic_num].bus = bus;
ir_ioapic[ir_ioapic_num].devfn = PCI_DEVFN(path->dev, path->fn);
ir_ioapic[ir_ioapic_num].iommu = iommu;
ir_ioapic[ir_ioapic_num].id = scope->enumeration_id;
ir_ioapic_num++;
}
static int ir_parse_ioapic_hpet_scope(struct acpi_dmar_header *header,
struct intel_iommu *iommu)
{
struct acpi_dmar_hardware_unit *drhd;
struct acpi_dmar_device_scope *scope;
void *start, *end;
drhd = (struct acpi_dmar_hardware_unit *)header;
start = (void *)(drhd + 1);
end = ((void *)drhd) + header->length;
while (start < end) {
scope = start;
if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_IOAPIC) {
if (ir_ioapic_num == MAX_IO_APICS) {
printk(KERN_WARNING "Exceeded Max IO APICS\n");
return -1;
}
printk(KERN_INFO "IOAPIC id %d under DRHD base"
" 0x%Lx\n", scope->enumeration_id,
drhd->address);
ir_parse_one_ioapic_scope(scope, iommu);
} else if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_HPET) {
if (ir_hpet_num == MAX_HPET_TBS) {
printk(KERN_WARNING "Exceeded Max HPET blocks\n");
return -1;
}
printk(KERN_INFO "HPET id %d under DRHD base"
" 0x%Lx\n", scope->enumeration_id,
drhd->address);
ir_parse_one_hpet_scope(scope, iommu);
}
start += scope->length;
}
return 0;
}
/*
* Finds the assocaition between IOAPIC's and its Interrupt-remapping
* hardware unit.
*/
int __init parse_ioapics_under_ir(void)
{
struct dmar_drhd_unit *drhd;
int ir_supported = 0;
for_each_drhd_unit(drhd) {
struct intel_iommu *iommu = drhd->iommu;
if (ecap_ir_support(iommu->ecap)) {
if (ir_parse_ioapic_hpet_scope(drhd->hdr, iommu))
return -1;
ir_supported = 1;
}
}
if (ir_supported && ir_ioapic_num != nr_ioapics) {
printk(KERN_WARNING
"Not all IO-APIC's listed under remapping hardware\n");
return -1;
}
return ir_supported;
}
void disable_intr_remapping(void)
{
struct dmar_drhd_unit *drhd;
struct intel_iommu *iommu = NULL;
/*
* Disable Interrupt-remapping for all the DRHD's now.
*/
for_each_iommu(iommu, drhd) {
if (!ecap_ir_support(iommu->ecap))
continue;
iommu_disable_intr_remapping(iommu);
}
}
int reenable_intr_remapping(int eim)
{
struct dmar_drhd_unit *drhd;
int setup = 0;
struct intel_iommu *iommu = NULL;
for_each_iommu(iommu, drhd)
if (iommu->qi)
dmar_reenable_qi(iommu);
/*
* Setup Interrupt-remapping for all the DRHD's now.
*/
for_each_iommu(iommu, drhd) {
if (!ecap_ir_support(iommu->ecap))
continue;
/* Set up interrupt remapping for iommu.*/
iommu_set_intr_remapping(iommu, eim);
setup = 1;
}
if (!setup)
goto error;
return 0;
error:
/*
* handle error condition gracefully here!
*/
return -1;
}