[6/7] iommu/vt-d: Enable page request interrupt

Commit Message

David Woodhouse Oct. 8, 2015, 11:53 p.m. UTC

Signed-off-by: David Woodhouse <[e-mail]>
---
 drivers/iommu/intel-iommu.c | 22 +++++++++++++-
 drivers/iommu/intel-svm.c   | 71 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/intel-iommu.h |  5 ++++
 3 files changed, 97 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index b5ab009..e27b9c6 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1687,8 +1687,11 @@  static void free_dmar_iommu(struct intel_iommu *iommu)
 	free_context_table(iommu);
 
 #ifdef CONFIG_INTEL_IOMMU_SVM
-	if (pasid_enabled(iommu))
+	if (pasid_enabled(iommu)) {
+		if (ecap_prs(iommu->ecap))
+			intel_svm_finish_prq(iommu);
 		intel_svm_free_pasid_tables(iommu);
+	}
 #endif
 }
 
@@ -3204,6 +3207,13 @@  domains_done:
 
 		iommu_flush_write_buffer(iommu);
 
+#ifdef CONFIG_INTEL_IOMMU_SVM
+		if (pasid_enabled(iommu) && ecap_prs(iommu->ecap)) {
+			ret = intel_svm_enable_prq(iommu);
+			if (ret)
+				goto free_iommu;
+		}
+#endif
 		ret = dmar_set_interrupt(iommu);
 		if (ret)
 			goto free_iommu;
@@ -4148,6 +4158,14 @@  static int intel_iommu_add(struct dmar_drhd_unit *dmaru)
 
 	intel_iommu_init_qi(iommu);
 	iommu_flush_write_buffer(iommu);
+
+#ifdef CONFIG_INTEL_IOMMU_SVM
+	if (pasid_enabled(iommu) && ecap_prs(iommu->ecap)) {
+		ret = intel_svm_enable_prq(iommu);
+		if (ret)
+			goto disable_iommu;
+	}
+#endif
 	ret = dmar_set_interrupt(iommu);
 	if (ret)
 		goto disable_iommu;
@@ -4952,6 +4970,8 @@  int intel_iommu_enable_pasid(struct intel_svm *svm)
 				ctx_lo |= CONTEXT_TT_PT_PASID << 2;
 		}
 		ctx_lo |= CONTEXT_PASIDE;
+		if (svm->dev_iotlb && ecap_prs(svm->iommu->ecap))
+			ctx_lo |= CONTEXT_PRS;
 		context[0].lo = ctx_lo;
 		wmb();
 		svm->iommu->flush.flush_context(svm->iommu, svm->did,
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 913c3a1..1260e87 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -18,6 +18,10 @@ 
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/intel-svm.h>
+#include <linux/dmar.h>
+#include <linux/interrupt.h>
+
+static irqreturn_t prq_event_thread(int irq, void *d);
 
 struct pasid_entry {
 	u64 val;
@@ -75,6 +79,65 @@  int intel_svm_free_pasid_tables(struct intel_iommu *iommu)
 	return 0;
 }
 
+#define PRQ_ORDER 0
+int intel_svm_enable_prq(struct intel_iommu *iommu)
+{
+	struct page *pages;
+	int irq, ret;
+
+	pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, PRQ_ORDER);
+	if (!pages) {
+		pr_warn("IOMMU: %s: Failed to allocate page request queue\n",
+			iommu->name);
+		return -ENOMEM;
+	}
+	iommu->prq = page_address(pages);
+
+	irq = dmar_alloc_hwirq(DMAR_UNITS_SUPPORTED + iommu->seq_id, iommu->node, iommu);
+	if (irq <= 0) {
+		pr_err("IOMMU: %s: Failed to create IRQ vector for page request queue\n",
+		       iommu->name);
+		ret = -EINVAL;
+	err:
+		free_pages((unsigned long)iommu->prq, PRQ_ORDER);
+		iommu->prq = 0;
+		return ret;
+	}
+	iommu->pr_irq = irq;
+
+	snprintf(iommu->prq_name, sizeof(iommu->prq_name), "dmar%d-prq", iommu->seq_id);
+
+	ret = request_threaded_irq(irq, NULL, prq_event_thread, IRQF_ONESHOT,
+				   iommu->prq_name, iommu);
+	if (ret) {
+		pr_err("IOMMU: %s: Failed to request IRQ for page request queue\n",
+		       iommu->name);
+		dmar_free_hwirq(irq);
+		goto err;
+	}
+	dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL);
+	dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL);
+	dmar_writeq(iommu->reg + DMAR_PQA_REG, virt_to_phys(iommu->prq) | PRQ_ORDER);
+
+	return 0;
+}
+
+int intel_svm_finish_prq(struct intel_iommu *iommu)
+{
+	dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL);
+	dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL);
+	dmar_writeq(iommu->reg + DMAR_PQA_REG, 0ULL);
+
+	free_irq(iommu->pr_irq, iommu);
+	dmar_free_hwirq(iommu->pr_irq);
+	iommu->pr_irq = 0;
+
+	free_pages((unsigned long)iommu->prq, PRQ_ORDER);
+	iommu->prq = 0;
+
+	return 0;
+}
+
 static void intel_flush_svm_range(struct intel_svm *svm,
 				  unsigned long address, int pages, int ih)
 {
@@ -292,3 +355,11 @@  int intel_svm_unbind_mm(struct device *dev, int pasid)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(intel_svm_unbind_mm);
+
+
+static irqreturn_t prq_event_thread(int irq, void *d)
+{
+	struct intel_iommu *iommu = d;
+	printk("PRQ event on %s\n", iommu->name);
+	return IRQ_HANDLED;
+}
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 564a61b..bf034b0 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -370,6 +370,7 @@  enum {
 
 struct pasid_entry;
 struct pasid_state_entry;
+struct page_req_dsc;
 
 struct intel_iommu {
 	void __iomem	*reg; /* Pointer to hardware regs, virtual addr */
@@ -402,6 +403,8 @@  struct intel_iommu {
 	 * told to. But while it's all driver-arbitrated, we're fine. */
 	struct pasid_entry *pasid_table;
 	struct pasid_state_entry *pasid_state_table;
+	struct page_req_dsc *prq;
+	unsigned char prq_name[16];    /* Name for PRQ interrupt */
 	struct idr pasid_idr;
 #endif
 	struct q_inval  *qi;            /* Queued invalidation info */
@@ -445,6 +448,8 @@  extern int dmar_ir_support(void);
 
 extern int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu);
 extern int intel_svm_free_pasid_tables(struct intel_iommu *iommu);
+extern int intel_svm_enable_prq(struct intel_iommu *iommu);
+extern int intel_svm_finish_prq(struct intel_iommu *iommu);
 
 struct intel_svm {
 	struct kref kref;