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Merge branch 'pci/host-vmd' into next

* pci/host-vmd:
  PCI: vmd: Fix suspend handlers defined-but-not-used warning
  PCI: vmd: Use SRCU as a local RCU to prevent delaying global RCU
  PCI: vmd: Remove unnecessary pci_set_drvdata()
Bjorn Helgaas 8 years ago
parent
commit
b08d2e61a6
2 changed files with 23 additions and 9 deletions
  1. 1 1
      drivers/pci/host/Kconfig
  2. 22 8
      drivers/pci/host/vmd.c

+ 1 - 1
drivers/pci/host/Kconfig

@@ -288,7 +288,7 @@ config PCIE_ROCKCHIP
 	  4 slots.
 
 config VMD
-	depends on PCI_MSI && X86_64
+	depends on PCI_MSI && X86_64 && SRCU
 	tristate "Intel Volume Management Device Driver"
 	default N
 	---help---

+ 22 - 8
drivers/pci/host/vmd.c

@@ -19,6 +19,7 @@
 #include <linux/module.h>
 #include <linux/msi.h>
 #include <linux/pci.h>
+#include <linux/srcu.h>
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
 
@@ -39,7 +40,6 @@ static DEFINE_RAW_SPINLOCK(list_lock);
 /**
  * struct vmd_irq - private data to map driver IRQ to the VMD shared vector
  * @node:	list item for parent traversal.
- * @rcu:	RCU callback item for freeing.
  * @irq:	back pointer to parent.
  * @enabled:	true if driver enabled IRQ
  * @virq:	the virtual IRQ value provided to the requesting driver.
@@ -49,7 +49,6 @@ static DEFINE_RAW_SPINLOCK(list_lock);
  */
 struct vmd_irq {
 	struct list_head	node;
-	struct rcu_head		rcu;
 	struct vmd_irq_list	*irq;
 	bool			enabled;
 	unsigned int		virq;
@@ -58,11 +57,13 @@ struct vmd_irq {
 /**
  * struct vmd_irq_list - list of driver requested IRQs mapping to a VMD vector
  * @irq_list:	the list of irq's the VMD one demuxes to.
+ * @srcu:	SRCU struct for local synchronization.
  * @count:	number of child IRQs assigned to this vector; used to track
  *		sharing.
  */
 struct vmd_irq_list {
 	struct list_head	irq_list;
+	struct srcu_struct	srcu;
 	unsigned int		count;
 };
 
@@ -224,14 +225,14 @@ static void vmd_msi_free(struct irq_domain *domain,
 	struct vmd_irq *vmdirq = irq_get_chip_data(virq);
 	unsigned long flags;
 
-	synchronize_rcu();
+	synchronize_srcu(&vmdirq->irq->srcu);
 
 	/* XXX: Potential optimization to rebalance */
 	raw_spin_lock_irqsave(&list_lock, flags);
 	vmdirq->irq->count--;
 	raw_spin_unlock_irqrestore(&list_lock, flags);
 
-	kfree_rcu(vmdirq, rcu);
+	kfree(vmdirq);
 }
 
 static int vmd_msi_prepare(struct irq_domain *domain, struct device *dev,
@@ -646,11 +647,12 @@ static irqreturn_t vmd_irq(int irq, void *data)
 {
 	struct vmd_irq_list *irqs = data;
 	struct vmd_irq *vmdirq;
+	int idx;
 
-	rcu_read_lock();
+	idx = srcu_read_lock(&irqs->srcu);
 	list_for_each_entry_rcu(vmdirq, &irqs->irq_list, node)
 		generic_handle_irq(vmdirq->virq);
-	rcu_read_unlock();
+	srcu_read_unlock(&irqs->srcu, idx);
 
 	return IRQ_HANDLED;
 }
@@ -696,6 +698,10 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		return -ENOMEM;
 
 	for (i = 0; i < vmd->msix_count; i++) {
+		err = init_srcu_struct(&vmd->irqs[i].srcu);
+		if (err)
+			return err;
+
 		INIT_LIST_HEAD(&vmd->irqs[i].irq_list);
 		err = devm_request_irq(&dev->dev, pci_irq_vector(dev, i),
 				       vmd_irq, 0, "vmd", &vmd->irqs[i]);
@@ -714,12 +720,20 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	return 0;
 }
 
+static void vmd_cleanup_srcu(struct vmd_dev *vmd)
+{
+	int i;
+
+	for (i = 0; i < vmd->msix_count; i++)
+		cleanup_srcu_struct(&vmd->irqs[i].srcu);
+}
+
 static void vmd_remove(struct pci_dev *dev)
 {
 	struct vmd_dev *vmd = pci_get_drvdata(dev);
 
 	vmd_detach_resources(vmd);
-	pci_set_drvdata(dev, NULL);
+	vmd_cleanup_srcu(vmd);
 	sysfs_remove_link(&vmd->dev->dev.kobj, "domain");
 	pci_stop_root_bus(vmd->bus);
 	pci_remove_root_bus(vmd->bus);
@@ -727,7 +741,7 @@ static void vmd_remove(struct pci_dev *dev)
 	irq_domain_remove(vmd->irq_domain);
 }
 
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
 static int vmd_suspend(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);