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-rw-r--r--drivers/iommu/intr_remapping.c797
1 files changed, 797 insertions, 0 deletions
diff --git a/drivers/iommu/intr_remapping.c b/drivers/iommu/intr_remapping.c
new file mode 100644
index 000000000000..1a89d4a2cadf
--- /dev/null
+++ b/drivers/iommu/intr_remapping.c
@@ -0,0 +1,797 @@
+#include <linux/interrupt.h>
+#include <linux/dmar.h>
+#include <linux/spinlock.h>
+#include <linux/slab.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>
+
+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 int disable_sourceid_checking;
+
+static __init int setup_nointremap(char *str)
+{
+ disable_intremap = 1;
+ return 0;
+}
+early_param("nointremap", setup_nointremap);
+
+static __init int setup_intremap(char *str)
+{
+ if (!str)
+ return -EINVAL;
+
+ if (!strncmp(str, "on", 2))
+ disable_intremap = 0;
+ else if (!strncmp(str, "off", 3))
+ disable_intremap = 1;
+ else if (!strncmp(str, "nosid", 5))
+ disable_sourceid_checking = 1;
+
+ return 0;
+}
+early_param("intremap", setup_intremap);
+
+static DEFINE_SPINLOCK(irq_2_ir_lock);
+
+static struct irq_2_iommu *irq_2_iommu(unsigned int irq)
+{
+ struct irq_cfg *cfg = irq_get_chip_data(irq);
+ return cfg ? &cfg->irq_2_iommu : NULL;
+}
+
+int get_irte(int irq, struct irte *entry)
+{
+ struct irq_2_iommu *irq_iommu = irq_2_iommu(irq);
+ unsigned long flags;
+ int index;
+
+ if (!entry || !irq_iommu)
+ return -1;
+
+ spin_lock_irqsave(&irq_2_ir_lock, flags);
+
+ 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 = irq_2_iommu(irq);
+ u16 index, start_index;
+ unsigned int mask = 0;
+ unsigned long flags;
+ int i;
+
+ if (!count || !irq_iommu)
+ return -1;
+
+ /*
+ * 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->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)
+{
+ struct irq_2_iommu *irq_iommu = irq_2_iommu(irq);
+ unsigned long flags;
+ int index;
+
+ if (!irq_iommu)
+ return -1;
+
+ spin_lock_irqsave(&irq_2_ir_lock, flags);
+ *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 = irq_2_iommu(irq);
+ unsigned long flags;
+
+ if (!irq_iommu)
+ return -1;
+
+ spin_lock_irqsave(&irq_2_ir_lock, flags);
+
+ 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 modify_irte(int irq, struct irte *irte_modified)
+{
+ struct irq_2_iommu *irq_iommu = irq_2_iommu(irq);
+ struct intel_iommu *iommu;
+ unsigned long flags;
+ struct irte *irte;
+ int rc, index;
+
+ if (!irq_iommu)
+ return -1;
+
+ spin_lock_irqsave(&irq_2_ir_lock, flags);
+
+ iommu = irq_iommu->iommu;
+
+ index = irq_iommu->irte_index + irq_iommu->sub_handle;
+ irte = &iommu->ir_table->base[index];
+
+ set_64bit(&irte->low, irte_modified->low);
+ set_64bit(&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;
+}
+
+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(&entry->low, 0);
+ set_64bit(&entry->high, 0);
+ }
+
+ return qi_flush_iec(iommu, index, irq_iommu->irte_mask);
+}
+
+int free_irte(int irq)
+{
+ struct irq_2_iommu *irq_iommu = irq_2_iommu(irq);
+ unsigned long flags;
+ int rc;
+
+ if (!irq_iommu)
+ return -1;
+
+ spin_lock_irqsave(&irq_2_ir_lock, flags);
+
+ 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 fields */
+#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)
+{
+ if (disable_sourceid_checking)
+ svt = SVT_NO_VERIFY;
+ 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 IOMMU %d\n", scope->enumeration_id,
+ drhd->address, iommu->seq_id);
+
+ 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;
+}
+