12 files changed, 1071 insertions, 112 deletions

diff --git a/arch/arm/mach-tegra/include/mach/smmu.h b/arch/arm/mach-tegra/include/mach/smmu.h
deleted file mode 100644
index dad403a9cf0..00000000000
--- a/arch/arm/mach-tegra/include/mach/smmu.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * IOMMU API for SMMU in Tegra30
- *
- * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-#ifndef	MACH_SMMU_H
-#define	MACH_SMMU_H
-
-enum smmu_hwgrp {
-	HWGRP_AFI,
-	HWGRP_AVPC,
-	HWGRP_DC,
-	HWGRP_DCB,
-	HWGRP_EPP,
-	HWGRP_G2,
-	HWGRP_HC,
-	HWGRP_HDA,
-	HWGRP_ISP,
-	HWGRP_MPE,
-	HWGRP_NV,
-	HWGRP_NV2,
-	HWGRP_PPCS,
-	HWGRP_SATA,
-	HWGRP_VDE,
-	HWGRP_VI,
-
-	HWGRP_COUNT,
-
-	HWGRP_END = ~0,
-};
-
-#define HWG_AFI		(1 << HWGRP_AFI)
-#define HWG_AVPC	(1 << HWGRP_AVPC)
-#define HWG_DC		(1 << HWGRP_DC)
-#define HWG_DCB		(1 << HWGRP_DCB)
-#define HWG_EPP		(1 << HWGRP_EPP)
-#define HWG_G2		(1 << HWGRP_G2)
-#define HWG_HC		(1 << HWGRP_HC)
-#define HWG_HDA		(1 << HWGRP_HDA)
-#define HWG_ISP		(1 << HWGRP_ISP)
-#define HWG_MPE		(1 << HWGRP_MPE)
-#define HWG_NV		(1 << HWGRP_NV)
-#define HWG_NV2		(1 << HWGRP_NV2)
-#define HWG_PPCS	(1 << HWGRP_PPCS)
-#define HWG_SATA	(1 << HWGRP_SATA)
-#define HWG_VDE		(1 << HWGRP_VDE)
-#define HWG_VI		(1 << HWGRP_VI)
-
-#endif	/* MACH_SMMU_H */
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 9f69b561f5d..e39f9dbf297 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -42,7 +42,7 @@ config AMD_IOMMU
 	select PCI_PRI
 	select PCI_PASID
 	select IOMMU_API
-	depends on X86_64 && PCI && ACPI
+	depends on X86_64 && PCI && ACPI && X86_IO_APIC
 	---help---
 	  With this option you can enable support for AMD IOMMU hardware in
 	  your system. An IOMMU is a hardware component which provides
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index e89daf1b21b..55074cba20e 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -31,6 +31,12 @@
 #include <linux/amd-iommu.h>
 #include <linux/notifier.h>
 #include <linux/export.h>
+#include <linux/irq.h>
+#include <linux/msi.h>
+#include <asm/irq_remapping.h>
+#include <asm/io_apic.h>
+#include <asm/apic.h>
+#include <asm/hw_irq.h>
 #include <asm/msidef.h>
 #include <asm/proto.h>
 #include <asm/iommu.h>
@@ -39,6 +45,7 @@
 
 #include "amd_iommu_proto.h"
 #include "amd_iommu_types.h"
+#include "irq_remapping.h"
 
 #define CMD_SET_TYPE(cmd, t) ((cmd)->data[1] |= ((t) << 28))
 
@@ -72,6 +79,9 @@ static DEFINE_SPINLOCK(iommu_pd_list_lock);
 static LIST_HEAD(dev_data_list);
 static DEFINE_SPINLOCK(dev_data_list_lock);
 
+LIST_HEAD(ioapic_map);
+LIST_HEAD(hpet_map);
+
 /*
  * Domain for untranslated devices - only allocated
  * if iommu=pt passed on kernel cmd line.
@@ -92,6 +102,8 @@ struct iommu_cmd {
 	u32 data[4];
 };
 
+struct kmem_cache *amd_iommu_irq_cache;
+
 static void update_domain(struct protection_domain *domain);
 static int __init alloc_passthrough_domain(void);
 
@@ -686,7 +698,7 @@ static void iommu_poll_ppr_log(struct amd_iommu *iommu)
 
 		/*
 		 * Release iommu->lock because ppr-handling might need to
-		 * re-aquire it
+		 * re-acquire it
 		 */
 		spin_unlock_irqrestore(&iommu->lock, flags);
 
@@ -804,7 +816,7 @@ static void build_inv_iommu_pages(struct iommu_cmd *cmd, u64 address,
 	CMD_SET_TYPE(cmd, CMD_INV_IOMMU_PAGES);
 	if (s) /* size bit - we flush more than one 4kb page */
 		cmd->data[2] |= CMD_INV_IOMMU_PAGES_SIZE_MASK;
-	if (pde) /* PDE bit - we wan't flush everything not only the PTEs */
+	if (pde) /* PDE bit - we want to flush everything, not only the PTEs */
 		cmd->data[2] |= CMD_INV_IOMMU_PAGES_PDE_MASK;
 }
 
@@ -899,6 +911,13 @@ static void build_inv_all(struct iommu_cmd *cmd)
 	CMD_SET_TYPE(cmd, CMD_INV_ALL);
 }
 
+static void build_inv_irt(struct iommu_cmd *cmd, u16 devid)
+{
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->data[0] = devid;
+	CMD_SET_TYPE(cmd, CMD_INV_IRT);
+}
+
 /*
  * Writes the command to the IOMMUs command buffer and informs the
  * hardware about the new command.
@@ -1020,12 +1039,32 @@ static void iommu_flush_all(struct amd_iommu *iommu)
 	iommu_completion_wait(iommu);
 }
 
+static void iommu_flush_irt(struct amd_iommu *iommu, u16 devid)
+{
+	struct iommu_cmd cmd;
+
+	build_inv_irt(&cmd, devid);
+
+	iommu_queue_command(iommu, &cmd);
+}
+
+static void iommu_flush_irt_all(struct amd_iommu *iommu)
+{
+	u32 devid;
+
+	for (devid = 0; devid <= MAX_DEV_TABLE_ENTRIES; devid++)
+		iommu_flush_irt(iommu, devid);
+
+	iommu_completion_wait(iommu);
+}
+
 void iommu_flush_all_caches(struct amd_iommu *iommu)
 {
 	if (iommu_feature(iommu, FEATURE_IA)) {
 		iommu_flush_all(iommu);
 	} else {
 		iommu_flush_dte_all(iommu);
+		iommu_flush_irt_all(iommu);
 		iommu_flush_tlb_all(iommu);
 	}
 }
@@ -2155,7 +2194,7 @@ static bool pci_pri_tlp_required(struct pci_dev *pdev)
 }
 
 /*
- * If a device is not yet associated with a domain, this function does
+ * If a device is not yet associated with a domain, this function
  * assigns it visible for the hardware
  */
 static int attach_device(struct device *dev,
@@ -2405,7 +2444,7 @@ static struct protection_domain *get_domain(struct device *dev)
 	if (domain != NULL)
 		return domain;
 
-	/* Device not bount yet - bind it */
+	/* Device not bound yet - bind it */
 	dma_dom = find_protection_domain(devid);
 	if (!dma_dom)
 		dma_dom = amd_iommu_rlookup_table[devid]->default_dom;
@@ -2944,7 +2983,7 @@ static void __init prealloc_protection_domains(void)
 			alloc_passthrough_domain();
 			dev_data->passthrough = true;
 			attach_device(&dev->dev, pt_domain);
-			pr_info("AMD-Vi: Using passthough domain for device %s\n",
+			pr_info("AMD-Vi: Using passthrough domain for device %s\n",
 				dev_name(&dev->dev));
 		}
 
@@ -3316,6 +3355,8 @@ static int amd_iommu_domain_has_cap(struct iommu_domain *domain,
 	switch (cap) {
 	case IOMMU_CAP_CACHE_COHERENCY:
 		return 1;
+	case IOMMU_CAP_INTR_REMAP:
+		return irq_remapping_enabled;
 	}
 
 	return 0;
@@ -3743,3 +3784,466 @@ int amd_iommu_device_info(struct pci_dev *pdev,
 	return 0;
 }
 EXPORT_SYMBOL(amd_iommu_device_info);
+
+#ifdef CONFIG_IRQ_REMAP
+
+/*****************************************************************************
+ *
+ * Interrupt Remapping Implementation
+ *
+ *****************************************************************************/
+
+union irte {
+	u32 val;
+	struct {
+		u32 valid	: 1,
+		    no_fault	: 1,
+		    int_type	: 3,
+		    rq_eoi	: 1,
+		    dm		: 1,
+		    rsvd_1	: 1,
+		    destination	: 8,
+		    vector	: 8,
+		    rsvd_2	: 8;
+	} fields;
+};
+
+#define DTE_IRQ_PHYS_ADDR_MASK	(((1ULL << 45)-1) << 6)
+#define DTE_IRQ_REMAP_INTCTL    (2ULL << 60)
+#define DTE_IRQ_TABLE_LEN       (8ULL << 1)
+#define DTE_IRQ_REMAP_ENABLE    1ULL
+
+static void set_dte_irq_entry(u16 devid, struct irq_remap_table *table)
+{
+	u64 dte;
+
+	dte	= amd_iommu_dev_table[devid].data[2];
+	dte	&= ~DTE_IRQ_PHYS_ADDR_MASK;
+	dte	|= virt_to_phys(table->table);
+	dte	|= DTE_IRQ_REMAP_INTCTL;
+	dte	|= DTE_IRQ_TABLE_LEN;
+	dte	|= DTE_IRQ_REMAP_ENABLE;
+
+	amd_iommu_dev_table[devid].data[2] = dte;
+}
+
+#define IRTE_ALLOCATED (~1U)
+
+static struct irq_remap_table *get_irq_table(u16 devid, bool ioapic)
+{
+	struct irq_remap_table *table = NULL;
+	struct amd_iommu *iommu;
+	unsigned long flags;
+	u16 alias;
+
+	write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+
+	iommu = amd_iommu_rlookup_table[devid];
+	if (!iommu)
+		goto out_unlock;
+
+	table = irq_lookup_table[devid];
+	if (table)
+		goto out;
+
+	alias = amd_iommu_alias_table[devid];
+	table = irq_lookup_table[alias];
+	if (table) {
+		irq_lookup_table[devid] = table;
+		set_dte_irq_entry(devid, table);
+		iommu_flush_dte(iommu, devid);
+		goto out;
+	}
+
+	/* Nothing there yet, allocate new irq remapping table */
+	table = kzalloc(sizeof(*table), GFP_ATOMIC);
+	if (!table)
+		goto out;
+
+	if (ioapic)
+		/* Keep the first 32 indexes free for IOAPIC interrupts */
+		table->min_index = 32;
+
+	table->table = kmem_cache_alloc(amd_iommu_irq_cache, GFP_ATOMIC);
+	if (!table->table) {
+		kfree(table);
+		table = NULL;
+		goto out;
+	}
+
+	memset(table->table, 0, MAX_IRQS_PER_TABLE * sizeof(u32));
+
+	if (ioapic) {
+		int i;
+
+		for (i = 0; i < 32; ++i)
+			table->table[i] = IRTE_ALLOCATED;
+	}
+
+	irq_lookup_table[devid] = table;
+	set_dte_irq_entry(devid, table);
+	iommu_flush_dte(iommu, devid);
+	if (devid != alias) {
+		irq_lookup_table[alias] = table;
+		set_dte_irq_entry(devid, table);
+		iommu_flush_dte(iommu, alias);
+	}
+
+out:
+	iommu_completion_wait(iommu);
+
+out_unlock:
+	write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+
+	return table;
+}
+
+static int alloc_irq_index(struct irq_cfg *cfg, u16 devid, int count)
+{
+	struct irq_remap_table *table;
+	unsigned long flags;
+	int index, c;
+
+	table = get_irq_table(devid, false);
+	if (!table)
+		return -ENODEV;
+
+	spin_lock_irqsave(&table->lock, flags);
+
+	/* Scan table for free entries */
+	for (c = 0, index = table->min_index;
+	     index < MAX_IRQS_PER_TABLE;
+	     ++index) {
+		if (table->table[index] == 0)
+			c += 1;
+		else
+			c = 0;
+
+		if (c == count)	{
+			struct irq_2_iommu *irte_info;
+
+			for (; c != 0; --c)
+				table->table[index - c + 1] = IRTE_ALLOCATED;
+
+			index -= count - 1;
+
+			irte_info             = &cfg->irq_2_iommu;
+			irte_info->sub_handle = devid;
+			irte_info->irte_index = index;
+			irte_info->iommu      = (void *)cfg;
+
+			goto out;
+		}
+	}
+
+	index = -ENOSPC;
+
+out:
+	spin_unlock_irqrestore(&table->lock, flags);
+
+	return index;
+}
+
+static int get_irte(u16 devid, int index, union irte *irte)
+{
+	struct irq_remap_table *table;
+	unsigned long flags;
+
+	table = get_irq_table(devid, false);
+	if (!table)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&table->lock, flags);
+	irte->val = table->table[index];
+	spin_unlock_irqrestore(&table->lock, flags);
+
+	return 0;
+}
+
+static int modify_irte(u16 devid, int index, union irte irte)
+{
+	struct irq_remap_table *table;
+	struct amd_iommu *iommu;
+	unsigned long flags;
+
+	iommu = amd_iommu_rlookup_table[devid];
+	if (iommu == NULL)
+		return -EINVAL;
+
+	table = get_irq_table(devid, false);
+	if (!table)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&table->lock, flags);
+	table->table[index] = irte.val;
+	spin_unlock_irqrestore(&table->lock, flags);
+
+	iommu_flush_irt(iommu, devid);
+	iommu_completion_wait(iommu);
+
+	return 0;
+}
+
+static void free_irte(u16 devid, int index)
+{
+	struct irq_remap_table *table;
+	struct amd_iommu *iommu;
+	unsigned long flags;
+
+	iommu = amd_iommu_rlookup_table[devid];
+	if (iommu == NULL)
+		return;
+
+	table = get_irq_table(devid, false);
+	if (!table)
+		return;
+
+	spin_lock_irqsave(&table->lock, flags);
+	table->table[index] = 0;
+	spin_unlock_irqrestore(&table->lock, flags);
+
+	iommu_flush_irt(iommu, devid);
+	iommu_completion_wait(iommu);
+}
+
+static int setup_ioapic_entry(int irq, struct IO_APIC_route_entry *entry,
+			      unsigned int destination, int vector,
+			      struct io_apic_irq_attr *attr)
+{
+	struct irq_remap_table *table;
+	struct irq_2_iommu *irte_info;
+	struct irq_cfg *cfg;
+	union irte irte;
+	int ioapic_id;
+	int index;
+	int devid;
+	int ret;
+
+	cfg = irq_get_chip_data(irq);
+	if (!cfg)
+		return -EINVAL;
+
+	irte_info = &cfg->irq_2_iommu;
+	ioapic_id = mpc_ioapic_id(attr->ioapic);
+	devid     = get_ioapic_devid(ioapic_id);
+
+	if (devid < 0)
+		return devid;
+
+	table = get_irq_table(devid, true);
+	if (table == NULL)
+		return -ENOMEM;
+
+	index = attr->ioapic_pin;
+
+	/* Setup IRQ remapping info */
+	irte_info->sub_handle = devid;
+	irte_info->irte_index = index;
+	irte_info->iommu      = (void *)cfg;
+
+	/* Setup IRTE for IOMMU */
+	irte.val		= 0;
+	irte.fields.vector      = vector;
+	irte.fields.int_type    = apic->irq_delivery_mode;
+	irte.fields.destination = destination;
+	irte.fields.dm          = apic->irq_dest_mode;
+	irte.fields.valid       = 1;
+
+	ret = modify_irte(devid, index, irte);
+	if (ret)
+		return ret;
+
+	/* Setup IOAPIC entry */
+	memset(entry, 0, sizeof(*entry));
+
+	entry->vector        = index;
+	entry->mask          = 0;
+	entry->trigger       = attr->trigger;
+	entry->polarity      = attr->polarity;
+
+	/*
+	 * Mask level triggered irqs.
+	 */
+	if (attr->trigger)
+		entry->mask = 1;
+
+	return 0;
+}
+
+static int set_affinity(struct irq_data *data, const struct cpumask *mask,
+			bool force)
+{
+	struct irq_2_iommu *irte_info;
+	unsigned int dest, irq;
+	struct irq_cfg *cfg;
+	union irte irte;
+	int err;
+
+	if (!config_enabled(CONFIG_SMP))
+		return -1;
+
+	cfg       = data->chip_data;
+	irq       = data->irq;
+	irte_info = &cfg->irq_2_iommu;
+
+	if (!cpumask_intersects(mask, cpu_online_mask))
+		return -EINVAL;
+
+	if (get_irte(irte_info->sub_handle, irte_info->irte_index, &irte))
+		return -EBUSY;
+
+	if (assign_irq_vector(irq, cfg, mask))
+		return -EBUSY;
+
+	err = apic->cpu_mask_to_apicid_and(cfg->domain, mask, &dest);
+	if (err) {
+		if (assign_irq_vector(irq, cfg, data->affinity))
+			pr_err("AMD-Vi: Failed to recover vector for irq %d\n", irq);
+		return err;
+	}
+
+	irte.fields.vector      = cfg->vector;
+	irte.fields.destination = dest;
+
+	modify_irte(irte_info->sub_handle, irte_info->irte_index, irte);
+
+	if (cfg->move_in_progress)
+		send_cleanup_vector(cfg);
+
+	cpumask_copy(data->affinity, mask);
+
+	return 0;
+}
+
+static int free_irq(int irq)
+{
+	struct irq_2_iommu *irte_info;
+	struct irq_cfg *cfg;
+
+	cfg = irq_get_chip_data(irq);
+	if (!cfg)
+		return -EINVAL;
+
+	irte_info = &cfg->irq_2_iommu;
+
+	free_irte(irte_info->sub_handle, irte_info->irte_index);
+
+	return 0;
+}
+
+static void compose_msi_msg(struct pci_dev *pdev,
+			    unsigned int irq, unsigned int dest,
+			    struct msi_msg *msg, u8 hpet_id)
+{
+	struct irq_2_iommu *irte_info;
+	struct irq_cfg *cfg;
+	union irte irte;
+
+	cfg = irq_get_chip_data(irq);
+	if (!cfg)
+		return;
+
+	irte_info = &cfg->irq_2_iommu;
+
+	irte.val		= 0;
+	irte.fields.vector	= cfg->vector;
+	irte.fields.int_type    = apic->irq_delivery_mode;
+	irte.fields.destination	= dest;
+	irte.fields.dm		= apic->irq_dest_mode;
+	irte.fields.valid	= 1;
+
+	modify_irte(irte_info->sub_handle, irte_info->irte_index, irte);
+
+	msg->address_hi = MSI_ADDR_BASE_HI;
+	msg->address_lo = MSI_ADDR_BASE_LO;
+	msg->data       = irte_info->irte_index;
+}
+
+static int msi_alloc_irq(struct pci_dev *pdev, int irq, int nvec)
+{
+	struct irq_cfg *cfg;
+	int index;
+	u16 devid;
+
+	if (!pdev)
+		return -EINVAL;
+
+	cfg = irq_get_chip_data(irq);
+	if (!cfg)
+		return -EINVAL;
+
+	devid = get_device_id(&pdev->dev);
+	index = alloc_irq_index(cfg, devid, nvec);
+
+	return index < 0 ? MAX_IRQS_PER_TABLE : index;
+}
+
+static int msi_setup_irq(struct pci_dev *pdev, unsigned int irq,
+			 int index, int offset)
+{
+	struct irq_2_iommu *irte_info;
+	struct irq_cfg *cfg;
+	u16 devid;
+
+	if (!pdev)
+		return -EINVAL;
+
+	cfg = irq_get_chip_data(irq);
+	if (!cfg)
+		return -EINVAL;
+
+	if (index >= MAX_IRQS_PER_TABLE)
+		return 0;
+
+	devid		= get_device_id(&pdev->dev);
+	irte_info	= &cfg->irq_2_iommu;
+
+	irte_info->sub_handle = devid;
+	irte_info->irte_index = index + offset;
+	irte_info->iommu      = (void *)cfg;
+
+	return 0;
+}
+
+static int setup_hpet_msi(unsigned int irq, unsigned int id)
+{
+	struct irq_2_iommu *irte_info;
+	struct irq_cfg *cfg;
+	int index, devid;
+
+	cfg = irq_get_chip_data(irq);
+	if (!cfg)
+		return -EINVAL;
+
+	irte_info = &cfg->irq_2_iommu;
+	devid     = get_hpet_devid(id);
+	if (devid < 0)
+		return devid;
+
+	index = alloc_irq_index(cfg, devid, 1);
+	if (index < 0)
+		return index;
+
+	irte_info->sub_handle = devid;
+	irte_info->irte_index = index;
+	irte_info->iommu      = (void *)cfg;
+
+	return 0;
+}
+
+struct irq_remap_ops amd_iommu_irq_ops = {
+	.supported		= amd_iommu_supported,
+	.prepare		= amd_iommu_prepare,
+	.enable			= amd_iommu_enable,
+	.disable		= amd_iommu_disable,
+	.reenable		= amd_iommu_reenable,
+	.enable_faulting	= amd_iommu_enable_faulting,
+	.setup_ioapic_entry	= setup_ioapic_entry,
+	.set_affinity		= set_affinity,
+	.free_irq		= free_irq,
+	.compose_msi_msg	= compose_msi_msg,
+	.msi_alloc_irq		= msi_alloc_irq,
+	.msi_setup_irq		= msi_setup_irq,
+	.setup_hpet_msi		= setup_hpet_msi,
+};
+#endif
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 18a89b760aa..18b0d99bd4d 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -26,16 +26,18 @@
 #include <linux/msi.h>
 #include <linux/amd-iommu.h>
 #include <linux/export.h>
-#include <linux/acpi.h>
 #include <acpi/acpi.h>
 #include <asm/pci-direct.h>
 #include <asm/iommu.h>
 #include <asm/gart.h>
 #include <asm/x86_init.h>
 #include <asm/iommu_table.h>
+#include <asm/io_apic.h>
+#include <asm/irq_remapping.h>
 
 #include "amd_iommu_proto.h"
 #include "amd_iommu_types.h"
+#include "irq_remapping.h"
 
 /*
  * definitions for the ACPI scanning code
@@ -55,6 +57,10 @@
 #define IVHD_DEV_ALIAS_RANGE            0x43
 #define IVHD_DEV_EXT_SELECT             0x46
 #define IVHD_DEV_EXT_SELECT_RANGE       0x47
+#define IVHD_DEV_SPECIAL		0x48
+
+#define IVHD_SPECIAL_IOAPIC		1
+#define IVHD_SPECIAL_HPET		2
 
 #define IVHD_FLAG_HT_TUN_EN_MASK        0x01
 #define IVHD_FLAG_PASSPW_EN_MASK        0x02
@@ -123,6 +129,7 @@ struct ivmd_header {
 } __attribute__((packed));
 
 bool amd_iommu_dump;
+bool amd_iommu_irq_remap __read_mostly;
 
 static bool amd_iommu_detected;
 static bool __initdata amd_iommu_disabled;
@@ -178,7 +185,13 @@ u16 *amd_iommu_alias_table;
 struct amd_iommu **amd_iommu_rlookup_table;
 
 /*
- * AMD IOMMU allows up to 2^16 differend protection domains. This is a bitmap
+ * This table is used to find the irq remapping table for a given device id
+ * quickly.
+ */
+struct irq_remap_table **irq_lookup_table;
+
+/*
+ * AMD IOMMU allows up to 2^16 different protection domains. This is a bitmap
  * to know which ones are already in use.
  */
 unsigned long *amd_iommu_pd_alloc_bitmap;
@@ -478,7 +491,7 @@ static int __init find_last_devid_acpi(struct acpi_table_header *table)
 
 /****************************************************************************
  *
- * The following functions belong the the code path which parses the ACPI table
+ * The following functions belong to the code path which parses the ACPI table
  * the second time. In this ACPI parsing iteration we allocate IOMMU specific
  * data structures, initialize the device/alias/rlookup table and also
  * basically initialize the hardware.
@@ -690,8 +703,33 @@ static void __init set_dev_entry_from_acpi(struct amd_iommu *iommu,
 	set_iommu_for_device(iommu, devid);
 }
 
+static int add_special_device(u8 type, u8 id, u16 devid)
+{
+	struct devid_map *entry;
+	struct list_head *list;
+
+	if (type != IVHD_SPECIAL_IOAPIC && type != IVHD_SPECIAL_HPET)
+		return -EINVAL;
+
+	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry)
+		return -ENOMEM;
+
+	entry->id    = id;
+	entry->devid = devid;
+
+	if (type == IVHD_SPECIAL_IOAPIC)
+		list = &ioapic_map;
+	else
+		list = &hpet_map;
+
+	list_add_tail(&entry->list, list);
+
+	return 0;
+}
+
 /*
- * Reads the device exclusion range from ACPI and initialize IOMMU with
+ * Reads the device exclusion range from ACPI and initializes the IOMMU with
  * it
  */
 static void __init set_device_exclusion_range(u16 devid, struct ivmd_header *m)
@@ -717,7 +755,7 @@ static void __init set_device_exclusion_range(u16 devid, struct ivmd_header *m)
  * Takes a pointer to an AMD IOMMU entry in the ACPI table and
  * initializes the hardware and our data structures with it.
  */
-static void __init init_iommu_from_acpi(struct amd_iommu *iommu,
+static int __init init_iommu_from_acpi(struct amd_iommu *iommu,
 					struct ivhd_header *h)
 {
 	u8 *p = (u8 *)h;
@@ -867,12 +905,43 @@ static void __init init_iommu_from_acpi(struct amd_iommu *iommu,
 							flags, ext_flags);
 			}
 			break;
+		case IVHD_DEV_SPECIAL: {
+			u8 handle, type;
+			const char *var;
+			u16 devid;
+			int ret;
+
+			handle = e->ext & 0xff;
+			devid  = (e->ext >>  8) & 0xffff;
+			type   = (e->ext >> 24) & 0xff;
+
+			if (type == IVHD_SPECIAL_IOAPIC)
+				var = "IOAPIC";
+			else if (type == IVHD_SPECIAL_HPET)
+				var = "HPET";
+			else
+				var = "UNKNOWN";
+
+			DUMP_printk("  DEV_SPECIAL(%s[%d])\t\tdevid: %02x:%02x.%x\n",
+				    var, (int)handle,
+				    PCI_BUS(devid),
+				    PCI_SLOT(devid),
+				    PCI_FUNC(devid));
+
+			set_dev_entry_from_acpi(iommu, devid, e->flags, 0);
+			ret = add_special_device(type, handle, devid);
+			if (ret)
+				return ret;
+			break;
+		}
 		default:
 			break;
 		}
 
 		p += ivhd_entry_length(p);
 	}
+
+	return 0;
 }
 
 /* Initializes the device->iommu mapping for the driver */
@@ -912,6 +981,8 @@ static void __init free_iommu_all(void)
  */
 static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
 {
+	int ret;
+
 	spin_lock_init(&iommu->lock);
 
 	/* Add IOMMU to internal data structures */
@@ -947,7 +1018,16 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
 
 	iommu->int_enabled = false;
 
-	init_iommu_from_acpi(iommu, h);
+	ret = init_iommu_from_acpi(iommu, h);
+	if (ret)
+		return ret;
+
+	/*
+	 * Make sure IOMMU is not considered to translate itself. The IVRS
+	 * table tells us so, but this is a lie!
+	 */
+	amd_iommu_rlookup_table[iommu->devid] = NULL;
+
 	init_iommu_devices(iommu);
 
 	return 0;
@@ -1115,9 +1195,11 @@ static void print_iommu_info(void)
 				if (iommu_feature(iommu, (1ULL << i)))
 					pr_cont(" %s", feat_str[i]);
 			}
-		}
 		pr_cont("\n");
+		}
 	}
+	if (irq_remapping_enabled)
+		pr_info("AMD-Vi: Interrupt remapping enabled\n");
 }
 
 static int __init amd_iommu_init_pci(void)
@@ -1141,7 +1223,7 @@ static int __init amd_iommu_init_pci(void)
 /****************************************************************************
  *
  * The following functions initialize the MSI interrupts for all IOMMUs
- * in the system. Its a bit challenging because there could be multiple
+ * in the system. It's a bit challenging because there could be multiple
  * IOMMUs per PCI BDF but we can call pci_enable_msi(x) only once per
  * pci_dev.
  *
@@ -1199,7 +1281,7 @@ enable_faults:
  *
  * The next functions belong to the third pass of parsing the ACPI
  * table. In this last pass the memory mapping requirements are
- * gathered (like exclusion and unity mapping reanges).
+ * gathered (like exclusion and unity mapping ranges).
  *
  ****************************************************************************/
 
@@ -1308,7 +1390,7 @@ static int __init init_memory_definitions(struct acpi_table_header *table)
  * Init the device table to not allow DMA access for devices and
  * suppress all page faults
  */
-static void init_device_table(void)
+static void init_device_table_dma(void)
 {
 	u32 devid;
 
@@ -1318,6 +1400,27 @@ static void init_device_table(void)
 	}
 }
 
+static void __init uninit_device_table_dma(void)
+{
+	u32 devid;
+
+	for (devid = 0; devid <= amd_iommu_last_bdf; ++devid) {
+		amd_iommu_dev_table[devid].data[0] = 0ULL;
+		amd_iommu_dev_table[devid].data[1] = 0ULL;
+	}
+}
+
+static void init_device_table(void)
+{
+	u32 devid;
+
+	if (!amd_iommu_irq_remap)
+		return;
+
+	for (devid = 0; devid <= amd_iommu_last_bdf; ++devid)
+		set_dev_entry_bit(devid, DEV_ENTRY_IRQ_TBL_EN);
+}
+
 static void iommu_init_flags(struct amd_iommu *iommu)
 {
 	iommu->acpi_flags & IVHD_FLAG_HT_TUN_EN_MASK ?
@@ -1466,10 +1569,14 @@ static struct syscore_ops amd_iommu_syscore_ops = {
 
 static void __init free_on_init_error(void)
 {
-	amd_iommu_uninit_devices();
+	free_pages((unsigned long)irq_lookup_table,
+		   get_order(rlookup_table_size));
 
-	free_pages((unsigned long)amd_iommu_pd_alloc_bitmap,
-		   get_order(MAX_DOMAIN_ID/8));
+	if (amd_iommu_irq_cache) {
+		kmem_cache_destroy(amd_iommu_irq_cache);
+		amd_iommu_irq_cache = NULL;
+
+	}
 
 	free_pages((unsigned long)amd_iommu_rlookup_table,
 		   get_order(rlookup_table_size));
@@ -1482,8 +1589,6 @@ static void __init free_on_init_error(void)
 
 	free_iommu_all();
 
-	free_unity_maps();
-
 #ifdef CONFIG_GART_IOMMU
 	/*
 	 * We failed to initialize the AMD IOMMU - try fallback to GART
@@ -1494,6 +1599,33 @@ static void __init free_on_init_error(void)
 #endif
 }
 
+static bool __init check_ioapic_information(void)
+{
+	int idx;
+
+	for (idx = 0; idx < nr_ioapics; idx++) {
+		int id = mpc_ioapic_id(idx);
+
+		if (get_ioapic_devid(id) < 0) {
+			pr_err(FW_BUG "AMD-Vi: IO-APIC[%d] not in IVRS table\n", id);
+			pr_err("AMD-Vi: Disabling interrupt remapping due to BIOS Bug\n");
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static void __init free_dma_resources(void)
+{
+	amd_iommu_uninit_devices();
+
+	free_pages((unsigned long)amd_iommu_pd_alloc_bitmap,
+		   get_order(MAX_DOMAIN_ID/8));
+
+	free_unity_maps();
+}
+
 /*
  * This is the hardware init function for AMD IOMMU in the system.
  * This function is called either from amd_iommu_init or from the interrupt
@@ -1580,9 +1712,6 @@ static int __init early_amd_iommu_init(void)
 	if (amd_iommu_pd_alloc_bitmap == NULL)
 		goto out;
 
-	/* init the device table */
-	init_device_table();
-
 	/*
 	 * let all alias entries point to itself
 	 */
@@ -1605,10 +1734,35 @@ static int __init early_amd_iommu_init(void)
 	if (ret)
 		goto out;
 
+	if (amd_iommu_irq_remap)
+		amd_iommu_irq_remap = check_ioapic_information();
+
+	if (amd_iommu_irq_remap) {
+		/*
+		 * Interrupt remapping enabled, create kmem_cache for the
+		 * remapping tables.
+		 */
+		amd_iommu_irq_cache = kmem_cache_create("irq_remap_cache",
+				MAX_IRQS_PER_TABLE * sizeof(u32),
+				IRQ_TABLE_ALIGNMENT,
+				0, NULL);
+		if (!amd_iommu_irq_cache)
+			goto out;
+
+		irq_lookup_table = (void *)__get_free_pages(
+				GFP_KERNEL | __GFP_ZERO,
+				get_order(rlookup_table_size));
+		if (!irq_lookup_table)
+			goto out;
+	}
+
 	ret = init_memory_definitions(ivrs_base);
 	if (ret)
 		goto out;
 
+	/* init the device table */
+	init_device_table();
+
 out:
 	/* Don't leak any ACPI memory */
 	early_acpi_os_unmap_memory((char __iomem *)ivrs_base, ivrs_size);
@@ -1652,13 +1806,22 @@ static bool detect_ivrs(void)
 	/* Make sure ACS will be enabled during PCI probe */
 	pci_request_acs();
 
+	if (!disable_irq_remap)
+		amd_iommu_irq_remap = true;
+
 	return true;
 }
 
 static int amd_iommu_init_dma(void)
 {
+	struct amd_iommu *iommu;
 	int ret;
 
+	init_device_table_dma();
+
+	for_each_iommu(iommu)
+		iommu_flush_all_caches(iommu);
+
 	if (iommu_pass_through)
 		ret = amd_iommu_init_passthrough();
 	else
@@ -1749,7 +1912,48 @@ static int __init iommu_go_to_state(enum iommu_init_state state)
 	return ret;
 }
 
+#ifdef CONFIG_IRQ_REMAP
+int __init amd_iommu_prepare(void)
+{
+	return iommu_go_to_state(IOMMU_ACPI_FINISHED);
+}
+
+int __init amd_iommu_supported(void)
+{
+	return amd_iommu_irq_remap ? 1 : 0;
+}
+
+int __init amd_iommu_enable(void)
+{
+	int ret;
+
+	ret = iommu_go_to_state(IOMMU_ENABLED);
+	if (ret)
+		return ret;
+
+	irq_remapping_enabled = 1;
+
+	return 0;
+}
+
+void amd_iommu_disable(void)
+{
+	amd_iommu_suspend();
+}
+
+int amd_iommu_reenable(int mode)
+{
+	amd_iommu_resume();
+
+	return 0;
+}
 
+int __init amd_iommu_enable_faulting(void)
+{
+	/* We enable MSI later when PCI is initialized */
+	return 0;
+}
+#endif
 
 /*
  * This is the core init function for AMD IOMMU hardware in the system.
@@ -1762,8 +1966,17 @@ static int __init amd_iommu_init(void)
 
 	ret = iommu_go_to_state(IOMMU_INITIALIZED);
 	if (ret) {
-		disable_iommus();
-		free_on_init_error();
+		free_dma_resources();
+		if (!irq_remapping_enabled) {
+			disable_iommus();
+			free_on_init_error();
+		} else {
+			struct amd_iommu *iommu;
+
+			uninit_device_table_dma();
+			for_each_iommu(iommu)
+				iommu_flush_all_caches(iommu);
+		}
 	}
 
 	return ret;
diff --git a/drivers/iommu/amd_iommu_proto.h b/drivers/iommu/amd_iommu_proto.h
index 1a7f41c6cc6..c294961bdd3 100644
--- a/drivers/iommu/amd_iommu_proto.h
+++ b/drivers/iommu/amd_iommu_proto.h
@@ -32,6 +32,14 @@ extern void amd_iommu_uninit_devices(void);
 extern void amd_iommu_init_notifier(void);
 extern void amd_iommu_init_api(void);
 
+/* Needed for interrupt remapping */
+extern int amd_iommu_supported(void);
+extern int amd_iommu_prepare(void);
+extern int amd_iommu_enable(void);
+extern void amd_iommu_disable(void);
+extern int amd_iommu_reenable(int);
+extern int amd_iommu_enable_faulting(void);
+
 /* IOMMUv2 specific functions */
 struct iommu_domain;</