Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86/apic changes from Ingo Molnar:
 "Main changes:

   - Multiple MSI support added to the APIC, PCI and AHCI code - acked
     by all relevant maintainers, by Alexander Gordeev.

     The advantage is that multiple AHCI ports can have multiple MSI
     irqs assigned, and can thus spread to multiple CPUs.

     [ Drivers can make use of this new facility via the
       pci_enable_msi_block_auto() method ]

   - x86 IOAPIC code from interrupt remapping cleanups from Joerg
     Roedel:

     These patches move all interrupt remapping specific checks out of
     the x86 core code and replaces the respective call-sites with
     function pointers.  As a result the interrupt remapping code is
     better abstraced from x86 core interrupt handling code.

   - Various smaller improvements, fixes and cleanups."

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
  x86/intel/irq_remapping: Clean up x2apic opt-out security warning mess
  x86, kvm: Fix intialization warnings in kvm.c
  x86, irq: Move irq_remapped out of x86 core code
  x86, io_apic: Introduce eoi_ioapic_pin call-back
  x86, msi: Introduce x86_msi.compose_msi_msg call-back
  x86, irq: Introduce setup_remapped_irq()
  x86, irq: Move irq_remapped() check into free_remapped_irq
  x86, io-apic: Remove !irq_remapped() check from __target_IO_APIC_irq()
  x86, io-apic: Move CONFIG_IRQ_REMAP code out of x86 core
  x86, irq: Add data structure to keep AMD specific irq remapping information
  x86, irq: Move irq_remapping_enabled declaration to iommu code
  x86, io_apic: Remove irq_remapping_enabled check in setup_timer_IRQ0_pin
  x86, io_apic: Move irq_remapping_enabled checks out of check_timer()
  x86, io_apic: Convert setup_ioapic_entry to function pointer
  x86, io_apic: Introduce set_affinity function pointer
  x86, msi: Use IRQ remapping specific setup_msi_irqs routine
  x86, hpet: Introduce x86_msi_ops.setup_hpet_msi
  x86, io_apic: Introduce x86_io_apic_ops.print_entries for debugging
  x86, io_apic: Introduce x86_io_apic_ops.disable()
  x86, apic: Mask IO-APIC and PIC unconditionally on LAPIC resume
  ...

10 files changed, 503 insertions, 32 deletions

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 497912732566..495aeed26779 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1061,6 +1061,86 @@ static inline void ahci_gtf_filter_workaround(struct ata_host *host)
 {}
 #endif
 
+int ahci_init_interrupts(struct pci_dev *pdev, struct ahci_host_priv *hpriv)
+{
+	int rc;
+	unsigned int maxvec;
+
+	if (!(hpriv->flags & AHCI_HFLAG_NO_MSI)) {
+		rc = pci_enable_msi_block_auto(pdev, &maxvec);
+		if (rc > 0) {
+			if ((rc == maxvec) || (rc == 1))
+				return rc;
+			/*
+			 * Assume that advantage of multipe MSIs is negated,
+			 * so fallback to single MSI mode to save resources
+			 */
+			pci_disable_msi(pdev);
+			if (!pci_enable_msi(pdev))
+				return 1;
+		}
+	}
+
+	pci_intx(pdev, 1);
+	return 0;
+}
+
+/**
+ *	ahci_host_activate - start AHCI host, request IRQs and register it
+ *	@host: target ATA host
+ *	@irq: base IRQ number to request
+ *	@n_msis: number of MSIs allocated for this host
+ *	@irq_handler: irq_handler used when requesting IRQs
+ *	@irq_flags: irq_flags used when requesting IRQs
+ *
+ *	Similar to ata_host_activate, but requests IRQs according to AHCI-1.1
+ *	when multiple MSIs were allocated. That is one MSI per port, starting
+ *	from @irq.
+ *
+ *	LOCKING:
+ *	Inherited from calling layer (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno otherwise.
+ */
+int ahci_host_activate(struct ata_host *host, int irq, unsigned int n_msis)
+{
+	int i, rc;
+
+	/* Sharing Last Message among several ports is not supported */
+	if (n_msis < host->n_ports)
+		return -EINVAL;
+
+	rc = ata_host_start(host);
+	if (rc)
+		return rc;
+
+	for (i = 0; i < host->n_ports; i++) {
+		rc = devm_request_threaded_irq(host->dev,
+			irq + i, ahci_hw_interrupt, ahci_thread_fn, IRQF_SHARED,
+			dev_driver_string(host->dev), host->ports[i]);
+		if (rc)
+			goto out_free_irqs;
+	}
+
+	for (i = 0; i < host->n_ports; i++)
+		ata_port_desc(host->ports[i], "irq %d", irq + i);
+
+	rc = ata_host_register(host, &ahci_sht);
+	if (rc)
+		goto out_free_all_irqs;
+
+	return 0;
+
+out_free_all_irqs:
+	i = host->n_ports;
+out_free_irqs:
+	for (i--; i >= 0; i--)
+		devm_free_irq(host->dev, irq + i, host->ports[i]);
+
+	return rc;
+}
+
 static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
 	unsigned int board_id = ent->driver_data;
@@ -1069,7 +1149,7 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct device *dev = &pdev->dev;
 	struct ahci_host_priv *hpriv;
 	struct ata_host *host;
-	int n_ports, i, rc;
+	int n_ports, n_msis, i, rc;
 	int ahci_pci_bar = AHCI_PCI_BAR_STANDARD;
 
 	VPRINTK("ENTER\n");
@@ -1156,11 +1236,12 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (ahci_sb600_enable_64bit(pdev))
 		hpriv->flags &= ~AHCI_HFLAG_32BIT_ONLY;
 
-	if ((hpriv->flags & AHCI_HFLAG_NO_MSI) || pci_enable_msi(pdev))
-		pci_intx(pdev, 1);
-
 	hpriv->mmio = pcim_iomap_table(pdev)[ahci_pci_bar];
 
+	n_msis = ahci_init_interrupts(pdev, hpriv);
+	if (n_msis > 1)
+		hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
+
 	/* save initial config */
 	ahci_pci_save_initial_config(pdev, hpriv);
 
@@ -1256,6 +1337,10 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	ahci_pci_print_info(host);
 
 	pci_set_master(pdev);
+
+	if (hpriv->flags & AHCI_HFLAG_MULTI_MSI)
+		return ahci_host_activate(host, pdev->irq, n_msis);
+
 	return ata_host_activate(host, pdev->irq, ahci_interrupt, IRQF_SHARED,
 				 &ahci_sht);
 }
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 9be471200a07..b830e6c9fe49 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -231,6 +231,7 @@ enum {
 	AHCI_HFLAG_DELAY_ENGINE		= (1 << 15), /* do not start engine on
 						        port start (wait until
 						        error-handling stage) */
+	AHCI_HFLAG_MULTI_MSI		= (1 << 16), /* multiple PCI MSIs */
 
 	/* ap->flags bits */
 
@@ -297,6 +298,8 @@ struct ahci_port_priv {
 	unsigned int		ncq_saw_d2h:1;
 	unsigned int		ncq_saw_dmas:1;
 	unsigned int		ncq_saw_sdb:1;
+	u32			intr_status;	/* interrupts to handle */
+	spinlock_t		lock;		/* protects parent ata_port */
 	u32 			intr_mask;	/* interrupts to enable */
 	bool			fbs_supported;	/* set iff FBS is supported */
 	bool			fbs_enabled;	/* set iff FBS is enabled */
@@ -359,7 +362,10 @@ void ahci_set_em_messages(struct ahci_host_priv *hpriv,
 			  struct ata_port_info *pi);
 int ahci_reset_em(struct ata_host *host);
 irqreturn_t ahci_interrupt(int irq, void *dev_instance);
+irqreturn_t ahci_hw_interrupt(int irq, void *dev_instance);
+irqreturn_t ahci_thread_fn(int irq, void *dev_instance);
 void ahci_print_info(struct ata_host *host, const char *scc_s);
+int ahci_host_activate(struct ata_host *host, int irq, unsigned int n_msis);
 
 static inline void __iomem *__ahci_port_base(struct ata_host *host,
 					     unsigned int port_no)
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 6cd7805e47ca..34c82167b962 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1655,19 +1655,16 @@ static void ahci_error_intr(struct ata_port *ap, u32 irq_stat)
 		ata_port_abort(ap);
 }
 
-static void ahci_port_intr(struct ata_port *ap)
+static void ahci_handle_port_interrupt(struct ata_port *ap,
+				       void __iomem *port_mmio, u32 status)
 {
-	void __iomem *port_mmio = ahci_port_base(ap);
 	struct ata_eh_info *ehi = &ap->link.eh_info;
 	struct ahci_port_priv *pp = ap->private_data;
 	struct ahci_host_priv *hpriv = ap->host->private_data;
 	int resetting = !!(ap->pflags & ATA_PFLAG_RESETTING);
-	u32 status, qc_active = 0;
+	u32 qc_active = 0;
 	int rc;
 
-	status = readl(port_mmio + PORT_IRQ_STAT);
-	writel(status, port_mmio + PORT_IRQ_STAT);
-
 	/* ignore BAD_PMP while resetting */
 	if (unlikely(resetting))
 		status &= ~PORT_IRQ_BAD_PMP;
@@ -1743,6 +1740,107 @@ static void ahci_port_intr(struct ata_port *ap)
 	}
 }
 
+void ahci_port_intr(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 status;
+
+	status = readl(port_mmio + PORT_IRQ_STAT);
+	writel(status, port_mmio + PORT_IRQ_STAT);
+
+	ahci_handle_port_interrupt(ap, port_mmio, status);
+}
+
+irqreturn_t ahci_thread_fn(int irq, void *dev_instance)
+{
+	struct ata_port *ap = dev_instance;
+	struct ahci_port_priv *pp = ap->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	unsigned long flags;
+	u32 status;
+
+	spin_lock_irqsave(&ap->host->lock, flags);
+	status = pp->intr_status;
+	if (status)
+		pp->intr_status = 0;
+	spin_unlock_irqrestore(&ap->host->lock, flags);
+
+	spin_lock_bh(ap->lock);
+	ahci_handle_port_interrupt(ap, port_mmio, status);
+	spin_unlock_bh(ap->lock);
+
+	return IRQ_HANDLED;
+}
+EXPORT_SYMBOL_GPL(ahci_thread_fn);
+
+void ahci_hw_port_interrupt(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+	struct ahci_port_priv *pp = ap->private_data;
+	u32 status;
+
+	status = readl(port_mmio + PORT_IRQ_STAT);
+	writel(status, port_mmio + PORT_IRQ_STAT);
+
+	pp->intr_status |= status;
+}
+
+irqreturn_t ahci_hw_interrupt(int irq, void *dev_instance)
+{
+	struct ata_port *ap_this = dev_instance;
+	struct ahci_port_priv *pp = ap_this->private_data;
+	struct ata_host *host = ap_this->host;
+	struct ahci_host_priv *hpriv = host->private_data;
+	void __iomem *mmio = hpriv->mmio;
+	unsigned int i;
+	u32 irq_stat, irq_masked;
+
+	VPRINTK("ENTER\n");
+
+	spin_lock(&host->lock);
+
+	irq_stat = readl(mmio + HOST_IRQ_STAT);
+
+	if (!irq_stat) {
+		u32 status = pp->intr_status;
+
+		spin_unlock(&host->lock);
+
+		VPRINTK("EXIT\n");
+
+		return status ? IRQ_WAKE_THREAD : IRQ_NONE;
+	}
+
+	irq_masked = irq_stat & hpriv->port_map;
+
+	for (i = 0; i < host->n_ports; i++) {
+		struct ata_port *ap;
+
+		if (!(irq_masked & (1 << i)))
+			continue;
+
+		ap = host->ports[i];
+		if (ap) {
+			ahci_hw_port_interrupt(ap);
+			VPRINTK("port %u\n", i);
+		} else {
+			VPRINTK("port %u (no irq)\n", i);
+			if (ata_ratelimit())
+				dev_warn(host->dev,
+					 "interrupt on disabled port %u\n", i);
+		}
+	}
+
+	writel(irq_stat, mmio + HOST_IRQ_STAT);
+
+	spin_unlock(&host->lock);
+
+	VPRINTK("EXIT\n");
+
+	return IRQ_WAKE_THREAD;
+}
+EXPORT_SYMBOL_GPL(ahci_hw_interrupt);
+
 irqreturn_t ahci_interrupt(int irq, void *dev_instance)
 {
 	struct ata_host *host = dev_instance;
@@ -2196,6 +2294,14 @@ static int ahci_port_start(struct ata_port *ap)
 	 */
 	pp->intr_mask = DEF_PORT_IRQ;
 
+	/*
+	 * Switch to per-port locking in case each port has its own MSI vector.
+	 */
+	if ((hpriv->flags & AHCI_HFLAG_MULTI_MSI)) {
+		spin_lock_init(&pp->lock);
+		ap->lock = &pp->lock;
+	}
+
 	ap->private_data = pp;
 
 	/* engage engines, captain */
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index c1c74e030a58..d33eaaf783ad 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -4017,10 +4017,10 @@ static int alloc_irq_index(struct irq_cfg *cfg, u16 devid, int count)
 
 			index -= count - 1;
 
+			cfg->remapped	      = 1;
 			irte_info             = &cfg->irq_2_iommu;
 			irte_info->sub_handle = devid;
 			irte_info->irte_index = index;
-			irte_info->iommu      = (void *)cfg;
 
 			goto out;
 		}
@@ -4127,9 +4127,9 @@ static int setup_ioapic_entry(int irq, struct IO_APIC_route_entry *entry,
 	index = attr->ioapic_pin;
 
 	/* Setup IRQ remapping info */
+	cfg->remapped	      = 1;
 	irte_info->sub_handle = devid;
 	irte_info->irte_index = index;
-	irte_info->iommu      = (void *)cfg;
 
 	/* Setup IRTE for IOMMU */
 	irte.val		= 0;
@@ -4288,9 +4288,9 @@ static int msi_setup_irq(struct pci_dev *pdev, unsigned int irq,
 	devid		= get_device_id(&pdev->dev);
 	irte_info	= &cfg->irq_2_iommu;
 
+	cfg->remapped	      = 1;
 	irte_info->sub_handle = devid;
 	irte_info->irte_index = index + offset;
-	irte_info->iommu      = (void *)cfg;
 
 	return 0;
 }
@@ -4314,9 +4314,9 @@ static int setup_hpet_msi(unsigned int irq, unsigned int id)
 	if (index < 0)
 		return index;
 
+	cfg->remapped	      = 1;
 	irte_info->sub_handle = devid;
 	irte_info->irte_index = index;
-	irte_info->iommu      = (void *)cfg;
 
 	return 0;
 }
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 86e2f4a62b9a..174bb654453d 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -41,6 +41,8 @@
 #include <asm/irq_remapping.h>
 #include <asm/iommu_table.h>
 
+#include "irq_remapping.h"
+
 /* No locks are needed as DMA remapping hardware unit
  * list is constructed at boot time and hotplug of
  * these units are not supported by the architecture.
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index eca28014ef3e..43d5c8b8e7ad 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -46,6 +46,8 @@
 #include <asm/cacheflush.h>
 #include <asm/iommu.h>
 
+#include "irq_remapping.h"
+
 #define ROOT_SIZE		VTD_PAGE_SIZE
 #define CONTEXT_SIZE		VTD_PAGE_SIZE
 
diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index af8904de1d44..f3b8f23b5d8f 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -68,6 +68,7 @@ static 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);
+	struct irq_cfg *cfg = irq_get_chip_data(irq);
 	u16 index, start_index;
 	unsigned int mask = 0;
 	unsigned long flags;
@@ -115,6 +116,7 @@ static int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
 	for (i = index; i < index + count; i++)
 		table->base[i].present = 1;
 
+	cfg->remapped = 1;
 	irq_iommu->iommu = iommu;
 	irq_iommu->irte_index =  index;
 	irq_iommu->sub_handle = 0;
@@ -155,6 +157,7 @@ static int map_irq_to_irte_handle(int irq, u16 *sub_handle)
 static int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, u16 subhandle)
 {
 	struct irq_2_iommu *irq_iommu = irq_2_iommu(irq);
+	struct irq_cfg *cfg = irq_get_chip_data(irq);
 	unsigned long flags;
 
 	if (!irq_iommu)
@@ -162,6 +165,7 @@ static int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, u16 subha
 
 	raw_spin_lock_irqsave(&irq_2_ir_lock, flags);
 
+	cfg->remapped = 1;
 	irq_iommu->iommu = iommu;
 	irq_iommu->irte_index = index;
 	irq_iommu->sub_handle = subhandle;
@@ -425,11 +429,22 @@ static void iommu_set_irq_remapping(struct intel_iommu *iommu, int mode)
 
 	/* Enable interrupt-remapping */
 	iommu->gcmd |= DMA_GCMD_IRE;
+	iommu->gcmd &= ~DMA_GCMD_CFI;  /* Block compatibility-format MSIs */
 	writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
 
 	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 		      readl, (sts & DMA_GSTS_IRES), sts);
 
+	/*
+	 * With CFI clear in the Global Command register, we should be
+	 * protected from dangerous (i.e. compatibility) interrupts
+	 * regardless of x2apic status.  Check just to be sure.
+	 */
+	if (sts & DMA_GSTS_CFIS)
+		WARN(1, KERN_WARNING
+			"Compatibility-format IRQs enabled despite intr remapping;\n"
+			"you are vulnerable to IRQ injection.\n");
+
 	raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
 }
 
@@ -526,20 +541,24 @@ static int __init intel_irq_remapping_supported(void)
 static int __init intel_enable_irq_remapping(void)
 {
 	struct dmar_drhd_unit *drhd;
+	bool x2apic_present;
 	int setup = 0;
 	int eim = 0;
 
+	x2apic_present = x2apic_supported();
+
 	if (parse_ioapics_under_ir() != 1) {
 		printk(KERN_INFO "Not enable interrupt remapping\n");
-		return -1;
+		goto error;
 	}
 
-	if (x2apic_supported()) {
+	if (x2apic_present) {
 		eim = !dmar_x2apic_optout();
-		WARN(!eim, KERN_WARNING
-			   "Your BIOS is broken and requested that x2apic be disabled\n"
-			   "This will leave your machine vulnerable to irq-injection attacks\n"
-			   "Use 'intremap=no_x2apic_optout' to override BIOS request\n");
+		if (!eim)
+			printk(KERN_WARNING
+				"Your BIOS is broken and requested that x2apic be disabled.\n"
+				"This will slightly decrease performance.\n"
+				"Use 'intremap=no_x2apic_optout' to override BIOS request.\n");
 	}
 
 	for_each_drhd_unit(drhd) {
@@ -578,7 +597,7 @@ static int __init intel_enable_irq_remapping(void)
 		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;
+			goto error;
 		}
 	}
 
@@ -594,7 +613,7 @@ static int __init intel_enable_irq_remapping(void)
 			printk(KERN_ERR "DRHD %Lx: failed to enable queued, "
 			       " invalidation, ecap %Lx, ret %d\n",
 			       drhd->reg_base_addr, iommu->ecap, ret);
-			return -1;
+			goto error;
 		}
 	}
 
@@ -617,6 +636,14 @@ static int __init intel_enable_irq_remapping(void)
 		goto error;
 
 	irq_remapping_enabled = 1;
+
+	/*
+	 * VT-d has a different layout for IO-APIC entries when
+	 * interrupt remapping is enabled. So it needs a special routine
+	 * to print IO-APIC entries for debugging purposes too.
+	 */
+	x86_io_apic_ops.print_entries = intel_ir_io_apic_print_entries;
+
 	pr_info("Enabled IRQ remapping in %s mode\n", eim ? "x2apic" : "xapic");
 
 	return eim ? IRQ_REMAP_X2APIC_MODE : IRQ_REMAP_XAPIC_MODE;
@@ -625,6 +652,11 @@ error:
 	/*
 	 * handle error condition gracefully here!
 	 */
+
+	if (x2apic_present)
+		WARN(1, KERN_WARNING
+			"Failed to enable irq remapping.  You are vulnerable to irq-injection attacks.\n");
+
 	return -1;
 }
 
diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
index faf85d6e33fe..d56f8c17c5fe 100644
--- a/drivers/iommu/irq_remapping.c
+++ b/drivers/iommu/irq_remapping.c
@@ -1,11 +1,18 @@
+#include <linux/seq_file.h>
+#include <linux/cpumask.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/cpumask.h>
 #include <linux/errno.h>
 #include <linux/msi.h>
+#include <linux/irq.h>
+#include <linux/pci.h>
 
 #include <asm/hw_irq.h>
 #include <asm/irq_remapping.h>
+#include <asm/processor.h>
+#include <asm/x86_init.h>
+#include <asm/apic.h>
 
 #include "irq_remapping.h"
 
@@ -17,6 +24,152 @@ int no_x2apic_optout;
 
 static struct irq_remap_ops *remap_ops;
 
+static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec);
+static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
+				  int index, int sub_handle);
+static int set_remapped_irq_affinity(struct irq_data *data,
+				     const struct cpumask *mask,
+				     bool force);
+
+static bool irq_remapped(struct irq_cfg *cfg)
+{
+	return (cfg->remapped == 1);
+}
+
+static void irq_remapping_disable_io_apic(void)
+{
+	/*
+	 * With interrupt-remapping, for now we will use virtual wire A
+	 * mode, as virtual wire B is little complex (need to configure
+	 * both IOAPIC RTE as well as interrupt-remapping table entry).
+	 * As this gets called during crash dump, keep this simple for
+	 * now.
+	 */
+	if (cpu_has_apic || apic_from_smp_config())
+		disconnect_bsp_APIC(0);
+}
+
+static int do_setup_msi_irqs(struct pci_dev *dev, int nvec)
+{
+	int node, ret, sub_handle, index = 0;
+	unsigned int irq;
+	struct msi_desc *msidesc;
+
+	nvec = __roundup_pow_of_two(nvec);
+
+	WARN_ON(!list_is_singular(&dev->msi_list));
+	msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
+	WARN_ON(msidesc->irq);
+	WARN_ON(msidesc->msi_attrib.multiple);
+
+	node = dev_to_node(&dev->dev);
+	irq = __create_irqs(get_nr_irqs_gsi(), nvec, node);
+	if (irq == 0)
+		return -ENOSPC;
+
+	msidesc->msi_attrib.multiple = ilog2(nvec);
+	for (sub_handle = 0; sub_handle < nvec; sub_handle++) {
+		if (!sub_handle) {
+			index = msi_alloc_remapped_irq(dev, irq, nvec);
+			if (index < 0) {
+				ret = index;
+				goto error;
+			}
+		} else {
+			ret = msi_setup_remapped_irq(dev, irq + sub_handle,
+						     index, sub_handle);
+			if (ret < 0)
+				goto error;
+		}
+		ret = setup_msi_irq(dev, msidesc, irq, sub_handle);
+		if (ret < 0)
+			goto error;
+	}
+	return 0;
+
+error:
+	destroy_irqs(irq, nvec);
+
+	/*
+	 * Restore altered MSI descriptor fields and prevent just destroyed
+	 * IRQs from tearing down again in default_teardown_msi_irqs()
+	 */
+	msidesc->irq = 0;
+	msidesc->msi_attrib.multiple = 0;
+
+	return ret;
+}
+
+static int do_setup_msix_irqs(struct pci_dev *dev, int nvec)
+{
+	int node, ret, sub_handle, index = 0;
+	struct msi_desc *msidesc;
+	unsigned int irq;
+
+	node		= dev_to_node(&dev->dev);
+	irq		= get_nr_irqs_gsi();
+	sub_handle	= 0;
+
+	list_for_each_entry(msidesc, &dev->msi_list, list) {
+
+		irq = create_irq_nr(irq, node);
+		if (irq == 0)
+			return -1;
+
+		if (sub_handle == 0)
+			ret = index = msi_alloc_remapped_irq(dev, irq, nvec);
+		else
+			ret = msi_setup_remapped_irq(dev, irq, index, sub_handle);
+
+		if (ret < 0)
+			goto error;
+
+		ret = setup_msi_irq(dev, msidesc, irq, 0);
+		if (ret < 0)
+			goto error;
+
+		sub_handle += 1;
+		irq        += 1;
+	}
+
+	return 0;
+
+error:
+	destroy_irq(irq);
+	return ret;
+}
+
+static int irq_remapping_setup_msi_irqs(struct pci_dev *dev,
+					int nvec, int type)
+{
+	if (type == PCI_CAP_ID_MSI)
+		return do_setup_msi_irqs(dev, nvec);
+	else
+		return do_setup_msix_irqs(dev, nvec);
+}
+
+void eoi_ioapic_pin_remapped(int apic, int pin, int vector)
+{
+	/*
+	 * Intr-remapping uses pin number as the virtual vector
+	 * in the RTE. Actual vector is programmed in
+	 * intr-remapping table entry. Hence for the io-apic
+	 * EOI we use the pin number.
+	 */
+	io_apic_eoi(apic, pin);
+}
+
+static void __init irq_remapping_modify_x86_ops(void)
+{
+	x86_io_apic_ops.disable		= irq_remapping_disable_io_apic;
+	x86_io_apic_ops.set_affinity	= set_remapped_irq_affinity;
+	x86_io_apic_ops.setup_entry	= setup_ioapic_remapped_entry;
+	x86_io_apic_ops.eoi_ioapic_pin	= eoi_ioapic_pin_remapped;
+	x86_msi.setup_msi_irqs		= irq_remapping_setup_msi_irqs;
+	x86_msi.setup_hpet_msi		= setup_hpet_msi_remapped;
+	x86_msi.compose_msi_msg		= compose_remapped_msi_msg;
+}
+
 static __init int setup_nointremap(char *str)
 {
 	disable_irq_remap = 1;
@@ -79,15 +232,24 @@ int __init irq_remapping_prepare(void)
 
 int __init irq_remapping_enable(void)
 {
+	int ret;
+
 	if (!remap_ops || !remap_ops->enable)
 		return -ENODEV;
 
-	return remap_ops->enable();
+	ret = remap_ops->enable();
+
+	if (irq_remapping_enabled)
+		irq_remapping_modify_x86_ops();
+
+	return ret;
 }
 
 void irq_remapping_disable(void)
 {
-	if (!remap_ops || !remap_ops->disable)
+	if (!irq_remapping_enabled ||
+	    !remap_ops ||
+	    !remap_ops->disable)
 		return;
 
 	remap_ops->disable();
@@ -95,7 +257,9 @@ void irq_remapping_disable(void)
 
 int irq_remapping_reenable(int mode)
 {
-	if (!remap_ops || !remap_ops->reenable)
+	if (!irq_remapping_enabled ||
+	    !remap_ops ||
+	    !remap_ops->reenable)
 		return 0;
 
 	return remap_ops->reenable(mode);
@@ -103,6 +267,9 @@ int irq_remapping_reenable(int mode)
 
 int __init irq_remap_enable_fault_handling(void)
 {
+	if (!irq_remapping_enabled)
+		return 0;
+
 	if (!remap_ops || !remap_ops->enable_faulting)
 		return -ENODEV;
 
@@ -133,23 +300,28 @@ int set_remapped_irq_affinity(struct irq_data *data, const struct cpumask *mask,
 
 void free_remapped_irq(int irq)
 {
+	struct irq_cfg *cfg = irq_get_chip_data(irq);
+
 	if (!remap_ops || !remap_ops->free_irq)
 		return;
 
-	remap_ops->free_irq(irq);
+	if (irq_remapped(cfg))
+		remap_ops->free_irq(irq);
 }
 
 void compose_remapped_msi_msg(struct pci_dev *pdev,
 			      unsigned int irq, unsigned int dest,
 			      struct msi_msg *msg, u8 hpet_id)
 {
-	if (!remap_ops || !remap_ops->compose_msi_msg)
-		return;
+	struct irq_cfg *cfg = irq_get_chip_data(irq);
 
-	remap_ops->compose_msi_msg(pdev, irq, dest, msg, hpet_id);
+	if (!irq_remapped(cfg))
+		native_compose_msi_msg(pdev, irq, dest, msg, hpet_id);
+	else if (remap_ops && remap_ops->compose_msi_msg)
+		remap_ops->compose_msi_msg(pdev, irq, dest, msg, hpet_id);
 }
 
-int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec)
+static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec)
 {
 	if (!remap_ops || !remap_ops->msi_alloc_irq)
 		return -ENODEV;
@@ -157,8 +329,8 @@ int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec)
 	return remap_ops->msi_alloc_irq(pdev, irq, nvec);
 }
 
-int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
-			   int index, int sub_handle)
+static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
+				  int index, int sub_handle)
 {
 	if (!remap_ops || !remap_ops->msi_setup_irq)
 		return -ENODEV;
@@ -173,3 +345,42 @@ int setup_hpet_msi_remapped(unsigned int irq, unsigned int id)
 
 	return remap_ops->setup_hpet_msi(irq, id);
 }
+
+void panic_if_irq_remap(const char *msg)
+{
+	if (irq_remapping_enabled)
+		panic(msg);
+}
+
+static void ir_ack_apic_edge(struct irq_data *data)
+{
+	ack_APIC_irq();
+}
+
+static void ir_ack_apic_level(struct irq_data *data)
+{
+	ack_APIC_irq();
+	eoi_ioapic_irq(data->irq, data->chip_data);
+}
+
+static void ir_print_prefix(struct irq_data *data, struct seq_file *p)
+{
+	seq_printf(p, " IR-%s", data->chip->name);
+}
+
+void irq_remap_modify_chip_defaults(struct irq_chip *chip)
+{
+	chip->irq_print_chip = ir_print_prefix;
+	chip->irq_ack = ir_ack_apic_edge;
+	chip->irq_eoi = ir_ack_apic_level;
+	chip->irq_set_affinity = x86_io_apic_ops.set_affinity;
+}
+
+bool setup_remapped_irq(int irq, struct irq_cfg *cfg, struct irq_chip *chip)
+{
+	if (!irq_remapped(cfg))
+		return false;
+	irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
+	irq_remap_modify_chip_defaults(chip);
+	return true;
+}
diff --git a/drivers/iommu/irq_remapping.h b/drivers/iommu/irq_remapping.h
index 95363acb583f..ecb637670405 100644
--- a/drivers/iommu/irq_remapping.h
+++ b/drivers/iommu/irq_remapping.h
@@ -34,6 +34,7 @@ struct msi_msg;
 extern int disable_irq_remap;
 extern int disable_sourceid_checking;
 extern int no_x2apic_optout;
+extern int irq_remapping_enabled;
 
 struct irq_remap_ops {
 	/* Check whether Interrupt Remapping is supported */
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 5099636a6e5f..00cc78c7aa04 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -845,6 +845,32 @@ int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
 }
 EXPORT_SYMBOL(pci_enable_msi_block);
 
+int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec)
+{
+	int ret, pos, nvec;
+	u16 msgctl;
+
+	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
+	if (!pos)
+		return -EINVAL;
+
+	pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
+	ret = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
+
+	if (maxvec)
+		*maxvec = ret;
+
+	do {
+		nvec = ret;
+		ret = pci_enable_msi_block(dev, nvec);
+	} while (ret > 0);
+
+	if (ret < 0)
+		return ret;
+	return nvec;
+}
+EXPORT_SYMBOL(pci_enable_msi_block_auto);
+
 void pci_msi_shutdown(struct pci_dev *dev)
 {
 	struct msi_desc *desc;