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path: root/drivers/iommu/intel_irq_remapping.c
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Diffstat (limited to 'drivers/iommu/intel_irq_remapping.c')
-rw-r--r--drivers/iommu/intel_irq_remapping.c96
1 files changed, 51 insertions, 45 deletions
diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index a55b207b9425..14de1ab223c8 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -32,8 +32,9 @@ struct hpet_scope {
 };
 
 #define IR_X2APIC_MODE(mode) (mode ? (1 << 11) : 0)
-#define IRTE_DEST(dest) ((x2apic_mode) ? dest : dest << 8)
+#define IRTE_DEST(dest) ((eim_mode) ? dest : dest << 8)
 
+static int __read_mostly eim_mode;
 static struct ioapic_scope ir_ioapic[MAX_IO_APICS];
 static struct hpet_scope ir_hpet[MAX_HPET_TBS];
 
@@ -481,11 +482,11 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
 	if (iommu->ir_table)
 		return 0;
 
-	ir_table = kzalloc(sizeof(struct ir_table), GFP_ATOMIC);
+	ir_table = kzalloc(sizeof(struct ir_table), GFP_KERNEL);
 	if (!ir_table)
 		return -ENOMEM;
 
-	pages = alloc_pages_node(iommu->node, GFP_ATOMIC | __GFP_ZERO,
+	pages = alloc_pages_node(iommu->node, GFP_KERNEL | __GFP_ZERO,
 				 INTR_REMAP_PAGE_ORDER);
 
 	if (!pages) {
@@ -566,13 +567,27 @@ static int __init dmar_x2apic_optout(void)
 	return dmar->flags & DMAR_X2APIC_OPT_OUT;
 }
 
-static int __init intel_irq_remapping_supported(void)
+static void __init intel_cleanup_irq_remapping(void)
+{
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu;
+
+	for_each_iommu(iommu, drhd) {
+		if (ecap_ir_support(iommu->ecap)) {
+			iommu_disable_irq_remapping(iommu);
+			intel_teardown_irq_remapping(iommu);
+		}
+	}
+
+	if (x2apic_supported())
+		pr_warn("Failed to enable irq remapping.  You are vulnerable to irq-injection attacks.\n");
+}
+
+static int __init intel_prepare_irq_remapping(void)
 {
 	struct dmar_drhd_unit *drhd;
 	struct intel_iommu *iommu;
 
-	if (disable_irq_remap)
-		return 0;
 	if (irq_remap_broken) {
 		printk(KERN_WARNING
 			"This system BIOS has enabled interrupt remapping\n"
@@ -581,38 +596,45 @@ static int __init intel_irq_remapping_supported(void)
 			"interrupt remapping is being disabled.  Please\n"
 			"contact your BIOS vendor for an update\n");
 		add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
-		disable_irq_remap = 1;
-		return 0;
+		return -ENODEV;
 	}
 
+	if (dmar_table_init() < 0)
+		return -ENODEV;
+
 	if (!dmar_ir_support())
-		return 0;
+		return -ENODEV;
+
+	if (parse_ioapics_under_ir() != 1) {
+		printk(KERN_INFO "Not enabling interrupt remapping\n");
+		goto error;
+	}
 
+	/* First make sure all IOMMUs support IRQ remapping */
 	for_each_iommu(iommu, drhd)
 		if (!ecap_ir_support(iommu->ecap))
-			return 0;
+			goto error;
 
-	return 1;
+	/* Do the allocations early */
+	for_each_iommu(iommu, drhd)
+		if (intel_setup_irq_remapping(iommu))
+			goto error;
+
+	return 0;
+
+error:
+	intel_cleanup_irq_remapping();
+	return -ENODEV;
 }
 
 static int __init intel_enable_irq_remapping(void)
 {
 	struct dmar_drhd_unit *drhd;
 	struct intel_iommu *iommu;
-	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");
-		goto error;
-	}
-
-	if (x2apic_present) {
-		pr_info("Queued invalidation will be enabled to support x2apic and Intr-remapping.\n");
-
+	if (x2apic_supported()) {
 		eim = !dmar_x2apic_optout();
 		if (!eim)
 			printk(KERN_WARNING
@@ -646,16 +668,15 @@ static int __init intel_enable_irq_remapping(void)
 	/*
 	 * check for the Interrupt-remapping support
 	 */
-	for_each_iommu(iommu, drhd) {
-		if (!ecap_ir_support(iommu->ecap))
-			continue;
-
+	for_each_iommu(iommu, drhd)
 		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);
-			goto error;
+			eim = 0;
 		}
-	}
+	eim_mode = eim;
+	if (eim)
+		pr_info("Queued invalidation will be enabled to support x2apic and Intr-remapping.\n");
 
 	/*
 	 * Enable queued invalidation for all the DRHD's.
@@ -675,12 +696,6 @@ static int __init intel_enable_irq_remapping(void)
 	 * Setup Interrupt-remapping for all the DRHD's now.
 	 */
 	for_each_iommu(iommu, drhd) {
-		if (!ecap_ir_support(iommu->ecap))
-			continue;
-
-		if (intel_setup_irq_remapping(iommu))
-			goto error;
-
 		iommu_set_irq_remapping(iommu, eim);
 		setup = 1;
 	}
@@ -702,15 +717,7 @@ static int __init intel_enable_irq_remapping(void)
 	return eim ? IRQ_REMAP_X2APIC_MODE : IRQ_REMAP_XAPIC_MODE;
 
 error:
-	for_each_iommu(iommu, drhd)
-		if (ecap_ir_support(iommu->ecap)) {
-			iommu_disable_irq_remapping(iommu);
-			intel_teardown_irq_remapping(iommu);
-		}
-
-	if (x2apic_present)
-		pr_warn("Failed to enable irq remapping.  You are vulnerable to irq-injection attacks.\n");
-
+	intel_cleanup_irq_remapping();
 	return -1;
 }
 
@@ -1199,8 +1206,7 @@ static int intel_alloc_hpet_msi(unsigned int irq, unsigned int id)
 }
 
 struct irq_remap_ops intel_irq_remap_ops = {
-	.supported		= intel_irq_remapping_supported,
-	.prepare		= dmar_table_init,
+	.prepare		= intel_prepare_irq_remapping,
 	.enable			= intel_enable_irq_remapping,
 	.disable		= disable_irq_remapping,
 	.reenable		= reenable_irq_remapping,