3 files changed, 35 insertions, 0 deletions

diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index 3bcb459905c4..0f57af72d8f8 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -581,6 +581,26 @@ error:
         return -ENODEV;
 }
 
+/*
+ * Set Posted-Interrupts capability.
+ */
+static inline void set_irq_posting_cap(void)
+{
+        struct dmar_drhd_unit *drhd;
+        struct intel_iommu *iommu;
+
+        if (!disable_irq_post) {
+                intel_irq_remap_ops.capability |= 1 << IRQ_POSTING_CAP;
+
+                for_each_iommu(iommu, drhd)
+                        if (!cap_pi_support(iommu->cap)) {
+                                intel_irq_remap_ops.capability &=
+                                                ~(1 << IRQ_POSTING_CAP);
+                                break;
+                        }
+        }
+}
+
 static int __init intel_enable_irq_remapping(void)
 {
         struct dmar_drhd_unit *drhd;
@@ -656,6 +676,8 @@ static int __init intel_enable_irq_remapping(void)
 
         irq_remapping_enabled = 1;
 
+        set_irq_posting_cap();
+
         pr_info("Enabled IRQ remapping in %s mode\n", eim ? "x2apic" : "xapic");
 
         return eim ? IRQ_REMAP_X2APIC_MODE : IRQ_REMAP_XAPIC_MODE;
@@ -856,6 +878,12 @@ static void disable_irq_remapping(void)
 
                 iommu_disable_irq_remapping(iommu);
         }
+
+        /*
+         * Clear Posted-Interrupts capability.
+         */
+        if (!disable_irq_post)
+                intel_irq_remap_ops.capability &= ~(1 << IRQ_POSTING_CAP);
 }
 
 static int reenable_irq_remapping(int eim)
@@ -883,6 +911,8 @@ static int reenable_irq_remapping(int eim)
         if (!setup)
                 goto error;
 
+        set_irq_posting_cap();
+
         return 0;
 
 error:
diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
index fc78b0d41f71..ed605a924ca2 100644
--- a/drivers/iommu/irq_remapping.c
+++ b/drivers/iommu/irq_remapping.c
@@ -22,6 +22,8 @@ int irq_remap_broken;
 int disable_sourceid_checking;
 int no_x2apic_optout;
 
+int disable_irq_post = 1;
+
 static int disable_irq_remap;
 static struct irq_remap_ops *remap_ops;
 
diff --git a/drivers/iommu/irq_remapping.h b/drivers/iommu/irq_remapping.h
index b6ca30d31986..039c7af7b190 100644
--- a/drivers/iommu/irq_remapping.h
+++ b/drivers/iommu/irq_remapping.h
@@ -34,6 +34,8 @@ extern int disable_sourceid_checking;
 extern int no_x2apic_optout;
 extern int irq_remapping_enabled;
 
+extern int disable_irq_post;
+
 struct irq_remap_ops {
         /* The supported capabilities */
         int capability;
@@ -69,6 +71,7 @@ extern void ir_ack_apic_edge(struct irq_data *data);
 
 #define irq_remapping_enabled 0
 #define irq_remap_broken      0
+#define disable_irq_post      1
 
 #endif /* CONFIG_IRQ_REMAP */