[tip:x86/apic] iommu, x86: Setup Posted-Interrupts capability for Intel iommu

[tip-bot for Feng Wu <tipbot@zytor.com>]

Commit-ID:  01c87cc1d2fc041821a6ff2e489650759116dec6
Gitweb:     http://git.kernel.org/tip/01c87cc1d2fc041821a6ff2e489650759116dec6
Author:     Feng Wu <feng.wu@intel.com>
AuthorDate: Fri, 5 Jun 2015 13:42:52 +0800
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 8 Jun 2015 15:41:32 +0200

iommu, x86: Setup Posted-Interrupts capability for Intel iommu

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

Signed-off-by: Feng Wu <feng.wu@intel.com>
Acked-by: Joerg Roedel <joro@8bytes.org>
Cc: jiang.liu@linux.intel.com
Cc: iommu@lists.linux-foundation.org
Cc: dwmw2@infradead.org
Link: http://lkml.kernel.org/r/1433482974-14614-8-git-send-email-feng.wu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/iommu/intel_irq_remapping.c | 30 ++++++++++++++++++++++++++++++
 drivers/iommu/irq_remapping.c       |  2 ++
 drivers/iommu/irq_remapping.h       |  3 +++
 3 files changed, 35 insertions(+)

diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index 3bcb459..0f57af7 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 fc78b0d..ed605a9 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 b6ca30d..039c7af 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 */