[v4 6/8] iommu, x86: Setup Posted-Interrupts capability for Intel iommu

[Feng Wu]

Set Posted-Interrupts capability for Intel iommu when IR is enabled,
clear it when IR is disabled.

Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx>
---
 drivers/iommu/intel_irq_remapping.c |   34 ++++++++++++++++++++++++++++++++++
 drivers/iommu/irq_remapping.c       |    2 ++
 drivers/iommu/irq_remapping.h       |    3 +++
 3 files changed, 39 insertions(+), 0 deletions(-)

diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index ab9057a..130a92b 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -635,6 +635,20 @@ static int __init intel_enable_irq_remapping(void)
 
 	irq_remapping_enabled = 1;
 
+	/*
+	 * Set Posted-Interrupts capability.
+	 */
+	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;
+			}
+	}
+
 	pr_info("Enabled IRQ remapping in %s mode\n", eim ? "x2apic" : "xapic");
 
 	return eim ? IRQ_REMAP_X2APIC_MODE : IRQ_REMAP_XAPIC_MODE;
@@ -843,6 +857,12 @@ 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)
@@ -870,6 +890,20 @@ static int reenable_irq_remapping(int eim)
 	if (!setup)
 		goto error;
 
+	/*
+	 * Set Posted-Interrupts capability.
+	 */
+	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;
+			}
+	}
+
 	return 0;
 
 error:
diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
index 3c3da04..e63e969 100644
--- a/drivers/iommu/irq_remapping.c
+++ b/drivers/iommu/irq_remapping.c
@@ -24,6 +24,8 @@ int irq_remap_broken;
 int disable_sourceid_checking;
 int no_x2apic_optout;
 
+int disable_irq_post = 1;
+
 static struct irq_remap_ops *remap_ops;
 
 static void irq_remapping_disable_io_apic(void)
diff --git a/drivers/iommu/irq_remapping.h b/drivers/iommu/irq_remapping.h
index 69b2a1c..fe6ef36 100644
--- a/drivers/iommu/irq_remapping.h
+++ b/drivers/iommu/irq_remapping.h
@@ -35,6 +35,8 @@ 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 capabilites */
 	int capability;
@@ -74,6 +76,7 @@ extern void ir_ack_apic_edge(struct irq_data *data);
 #define irq_remapping_enabled 0
 #define disable_irq_remap     1
 #define irq_remap_broken      0
+#define disable_irq_post      1
 
 #endif /* CONFIG_IRQ_REMAP */
 
-- 
1.7.1

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