[v10 08/10] iommu, x86: Setup Posted-Interrupts capability for Intel iommu

From: Feng Wu
Date: Tue Jun 09 2015 - 01:30:57 EST


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

Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Joerg Roedel <joro@xxxxxxxxxx>
---
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 */

--
2.1.0

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