string: factorize skip_spaces and export it to be generally available
[safe/jmp/linux-2.6] / drivers / pci / intr_remapping.c
index a80b879..1487bf2 100644 (file)
+#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 "intel-iommu.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 int ir_ioapic_num;
+static struct hpet_scope ir_hpet[MAX_HPET_TBS];
+static int ir_ioapic_num, ir_hpet_num;
+int intr_remapping_enabled;
 
-static int ir_parse_ioapic_scope(struct acpi_dmar_header *header,
-                                struct intel_iommu *iommu)
+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(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;
@@ -30,9 +834,18 @@ static int ir_parse_ioapic_scope(struct acpi_dmar_header *header,
                               " 0x%Lx\n", scope->enumeration_id,
                               drhd->address);
 
-                       ir_ioapic[ir_ioapic_num].iommu = iommu;
-                       ir_ioapic[ir_ioapic_num].id = scope->enumeration_id;
-                       ir_ioapic_num++;
+                       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;
        }
@@ -53,7 +866,7 @@ int __init parse_ioapics_under_ir(void)
                struct intel_iommu *iommu = drhd->iommu;
 
                if (ecap_ir_support(iommu->ecap)) {
-                       if (ir_parse_ioapic_scope(drhd->hdr, iommu))
+                       if (ir_parse_ioapic_hpet_scope(drhd->hdr, iommu))
                                return -1;
 
                        ir_supported = 1;
@@ -68,3 +881,54 @@ int __init parse_ioapics_under_ir(void)
 
        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;
+}
+