1 files changed, 120 insertions, 28 deletions

diff --git a/drivers/iommu/intel/irq_remapping.c b/drivers/iommu/intel/irq_remapping.c
index 566297bc87..e4a7088667 100644
--- a/drivers/iommu/intel/irq_remapping.c
+++ b/drivers/iommu/intel/irq_remapping.c
@@ -19,9 +19,11 @@
 #include <asm/cpu.h>
 #include <asm/irq_remapping.h>
 #include <asm/pci-direct.h>
+#include <asm/posted_intr.h>
 
 #include "iommu.h"
 #include "../irq_remapping.h"
+#include "../iommu-pages.h"
 #include "cap_audit.h"
 
 enum irq_mode {
@@ -49,6 +51,7 @@ struct irq_2_iommu {
 	u16 sub_handle;
 	u8  irte_mask;
 	enum irq_mode mode;
+	bool posted_msi;
 };
 
 struct intel_ir_data {
@@ -82,7 +85,7 @@ static const struct irq_domain_ops intel_ir_domain_ops;
 
 static void iommu_disable_irq_remapping(struct intel_iommu *iommu);
 static int __init parse_ioapics_under_ir(void);
-static const struct msi_parent_ops dmar_msi_parent_ops, virt_dmar_msi_parent_ops;
+static const struct msi_parent_ops dmar_msi_parent_ops;
 
 static bool ir_pre_enabled(struct intel_iommu *iommu)
 {
@@ -527,7 +530,7 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
 	struct ir_table *ir_table;
 	struct fwnode_handle *fn;
 	unsigned long *bitmap;
-	struct page *pages;
+	void *ir_table_base;
 
 	if (iommu->ir_table)
 		return 0;
@@ -536,9 +539,9 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
 	if (!ir_table)
 		return -ENOMEM;
 
-	pages = alloc_pages_node(iommu->node, GFP_KERNEL | __GFP_ZERO,
-				 INTR_REMAP_PAGE_ORDER);
-	if (!pages) {
+	ir_table_base = iommu_alloc_pages_node(iommu->node, GFP_KERNEL,
+					       INTR_REMAP_PAGE_ORDER);
+	if (!ir_table_base) {
 		pr_err("IR%d: failed to allocate pages of order %d\n",
 		       iommu->seq_id, INTR_REMAP_PAGE_ORDER);
 		goto out_free_table;
@@ -567,13 +570,9 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
 	irq_domain_update_bus_token(iommu->ir_domain,  DOMAIN_BUS_DMAR);
 	iommu->ir_domain->flags |= IRQ_DOMAIN_FLAG_MSI_PARENT |
 				   IRQ_DOMAIN_FLAG_ISOLATED_MSI;
+	iommu->ir_domain->msi_parent_ops = &dmar_msi_parent_ops;
 
-	if (cap_caching_mode(iommu->cap))
-		iommu->ir_domain->msi_parent_ops = &virt_dmar_msi_parent_ops;
-	else
-		iommu->ir_domain->msi_parent_ops = &dmar_msi_parent_ops;
-
-	ir_table->base = page_address(pages);
+	ir_table->base = ir_table_base;
 	ir_table->bitmap = bitmap;
 	iommu->ir_table = ir_table;
 
@@ -622,7 +621,7 @@ out_free_fwnode:
 out_free_bitmap:
 	bitmap_free(bitmap);
 out_free_pages:
-	__free_pages(pages, INTR_REMAP_PAGE_ORDER);
+	iommu_free_pages(ir_table_base, INTR_REMAP_PAGE_ORDER);
 out_free_table:
 	kfree(ir_table);
 
@@ -643,8 +642,7 @@ static void intel_teardown_irq_remapping(struct intel_iommu *iommu)
 			irq_domain_free_fwnode(fn);
 			iommu->ir_domain = NULL;
 		}
-		free_pages((unsigned long)iommu->ir_table->base,
-			   INTR_REMAP_PAGE_ORDER);
+		iommu_free_pages(iommu->ir_table->base, INTR_REMAP_PAGE_ORDER);
 		bitmap_free(iommu->ir_table->bitmap);
 		kfree(iommu->ir_table);
 		iommu->ir_table = NULL;
@@ -1118,6 +1116,14 @@ static void prepare_irte(struct irte *irte, int vector, unsigned int dest)
 	irte->redir_hint = 1;
 }
 
+static void prepare_irte_posted(struct irte *irte)
+{
+	memset(irte, 0, sizeof(*irte));
+
+	irte->present = 1;
+	irte->p_pst = 1;
+}
+
 struct irq_remap_ops intel_irq_remap_ops = {
 	.prepare		= intel_prepare_irq_remapping,
 	.enable			= intel_enable_irq_remapping,
@@ -1126,6 +1132,47 @@ struct irq_remap_ops intel_irq_remap_ops = {
 	.enable_faulting	= enable_drhd_fault_handling,
 };
 
+#ifdef CONFIG_X86_POSTED_MSI
+
+static phys_addr_t get_pi_desc_addr(struct irq_data *irqd)
+{
+	int cpu = cpumask_first(irq_data_get_effective_affinity_mask(irqd));
+
+	if (WARN_ON(cpu >= nr_cpu_ids))
+		return 0;
+
+	return __pa(per_cpu_ptr(&posted_msi_pi_desc, cpu));
+}
+
+static void intel_ir_reconfigure_irte_posted(struct irq_data *irqd)
+{
+	struct intel_ir_data *ir_data = irqd->chip_data;
+	struct irte *irte = &ir_data->irte_entry;
+	struct irte irte_pi;
+	u64 pid_addr;
+
+	pid_addr = get_pi_desc_addr(irqd);
+
+	if (!pid_addr) {
+		pr_warn("Failed to setup IRQ %d for posted mode", irqd->irq);
+		return;
+	}
+
+	memset(&irte_pi, 0, sizeof(irte_pi));
+
+	/* The shared IRTE already be set up as posted during alloc_irte */
+	dmar_copy_shared_irte(&irte_pi, irte);
+
+	irte_pi.pda_l = (pid_addr >> (32 - PDA_LOW_BIT)) & ~(-1UL << PDA_LOW_BIT);
+	irte_pi.pda_h = (pid_addr >> 32) & ~(-1UL << PDA_HIGH_BIT);
+
+	modify_irte(&ir_data->irq_2_iommu, &irte_pi);
+}
+
+#else
+static inline void intel_ir_reconfigure_irte_posted(struct irq_data *irqd) {}
+#endif
+
 static void intel_ir_reconfigure_irte(struct irq_data *irqd, bool force)
 {
 	struct intel_ir_data *ir_data = irqd->chip_data;
@@ -1139,8 +1186,9 @@ static void intel_ir_reconfigure_irte(struct irq_data *irqd, bool force)
 	irte->vector = cfg->vector;
 	irte->dest_id = IRTE_DEST(cfg->dest_apicid);
 
-	/* Update the hardware only if the interrupt is in remapped mode. */
-	if (force || ir_data->irq_2_iommu.mode == IRQ_REMAPPING)
+	if (ir_data->irq_2_iommu.posted_msi)
+		intel_ir_reconfigure_irte_posted(irqd);
+	else if (force || ir_data->irq_2_iommu.mode == IRQ_REMAPPING)
 		modify_irte(&ir_data->irq_2_iommu, irte);
 }
 
@@ -1194,7 +1242,7 @@ static int intel_ir_set_vcpu_affinity(struct irq_data *data, void *info)
 	struct intel_ir_data *ir_data = data->chip_data;
 	struct vcpu_data *vcpu_pi_info = info;
 
-	/* stop posting interrupts, back to remapping mode */
+	/* stop posting interrupts, back to the default mode */
 	if (!vcpu_pi_info) {
 		modify_irte(&ir_data->irq_2_iommu, &ir_data->irte_entry);
 	} else {
@@ -1233,6 +1281,49 @@ static struct irq_chip intel_ir_chip = {
 	.irq_set_vcpu_affinity	= intel_ir_set_vcpu_affinity,
 };
 
+/*
+ * With posted MSIs, all vectors are multiplexed into a single notification
+ * vector. Devices MSIs are then dispatched in a demux loop where
+ * EOIs can be coalesced as well.
+ *
+ * "INTEL-IR-POST" IRQ chip does not do EOI on ACK, thus the dummy irq_ack()
+ * function. Instead EOI is performed by the posted interrupt notification
+ * handler.
+ *
+ * For the example below, 3 MSIs are coalesced into one CPU notification. Only
+ * one apic_eoi() is needed.
+ *
+ * __sysvec_posted_msi_notification()
+ *	irq_enter();
+ *		handle_edge_irq()
+ *			irq_chip_ack_parent()
+ *				dummy(); // No EOI
+ *			handle_irq_event()
+ *				driver_handler()
+ *		handle_edge_irq()
+ *			irq_chip_ack_parent()
+ *				dummy(); // No EOI
+ *			handle_irq_event()
+ *				driver_handler()
+ *		handle_edge_irq()
+ *			irq_chip_ack_parent()
+ *				dummy(); // No EOI
+ *			handle_irq_event()
+ *				driver_handler()
+ *	apic_eoi()
+ *	irq_exit()
+ */
+
+static void dummy_ack(struct irq_data *d) { }
+
+static struct irq_chip intel_ir_chip_post_msi = {
+	.name			= "INTEL-IR-POST",
+	.irq_ack		= dummy_ack,
+	.irq_set_affinity	= intel_ir_set_affinity,
+	.irq_compose_msi_msg	= intel_ir_compose_msi_msg,
+	.irq_set_vcpu_affinity	= intel_ir_set_vcpu_affinity,
+};
+
 static void fill_msi_msg(struct msi_msg *msg, u32 index, u32 subhandle)
 {
 	memset(msg, 0, sizeof(*msg));
@@ -1274,6 +1365,11 @@ static void intel_irq_remapping_prepare_irte(struct intel_ir_data *data,
 		break;
 	case X86_IRQ_ALLOC_TYPE_PCI_MSI:
 	case X86_IRQ_ALLOC_TYPE_PCI_MSIX:
+		if (posted_msi_supported()) {
+			prepare_irte_posted(irte);
+			data->irq_2_iommu.posted_msi = 1;
+		}
+
 		set_msi_sid(irte,
 			    pci_real_dma_dev(msi_desc_to_pci_dev(info->desc)));
 		break;
@@ -1361,7 +1457,12 @@ static int intel_irq_remapping_alloc(struct irq_domain *domain,
 
 		irq_data->hwirq = (index << 16) + i;
 		irq_data->chip_data = ird;
-		irq_data->chip = &intel_ir_chip;
+		if (posted_msi_supported() &&
+		    ((info->type == X86_IRQ_ALLOC_TYPE_PCI_MSI) ||
+		     (info->type == X86_IRQ_ALLOC_TYPE_PCI_MSIX)))
+			irq_data->chip = &intel_ir_chip_post_msi;
+		else
+			irq_data->chip = &intel_ir_chip;
 		intel_irq_remapping_prepare_irte(ird, irq_cfg, info, index, i);
 		irq_set_status_flags(virq + i, IRQ_MOVE_PCNTXT);
 	}
@@ -1421,20 +1522,11 @@ static const struct irq_domain_ops intel_ir_domain_ops = {
 };
 
 static const struct msi_parent_ops dmar_msi_parent_ops = {
-	.supported_flags	= X86_VECTOR_MSI_FLAGS_SUPPORTED |
-				  MSI_FLAG_MULTI_PCI_MSI |
-				  MSI_FLAG_PCI_IMS,
+	.supported_flags	= X86_VECTOR_MSI_FLAGS_SUPPORTED | MSI_FLAG_MULTI_PCI_MSI,
 	.prefix			= "IR-",
 	.init_dev_msi_info	= msi_parent_init_dev_msi_info,
 };
 
-static const struct msi_parent_ops virt_dmar_msi_parent_ops = {
-	.supported_flags	= X86_VECTOR_MSI_FLAGS_SUPPORTED |
-				  MSI_FLAG_MULTI_PCI_MSI,
-	.prefix			= "vIR-",
-	.init_dev_msi_info	= msi_parent_init_dev_msi_info,
-};
-
 /*
  * Support of Interrupt Remapping Unit Hotplug
  */