1 files changed, 46 insertions, 85 deletions

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index a8099d4d0c9d..eeb9fb2b47aa 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -17,34 +17,15 @@
 
 #include "pci.h"
 
-static int ats_alloc_one(struct pci_dev *dev, int ps)
+void pci_ats_init(struct pci_dev *dev)
 {
 	int pos;
-	u16 cap;
-	struct pci_ats *ats;
 
 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
 	if (!pos)
-		return -ENODEV;
-
-	ats = kzalloc(sizeof(*ats), GFP_KERNEL);
-	if (!ats)
-		return -ENOMEM;
-
-	ats->pos = pos;
-	ats->stu = ps;
-	pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap);
-	ats->qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
-					    PCI_ATS_MAX_QDEP;
-	dev->ats = ats;
-
-	return 0;
-}
+		return;
 
-static void ats_free_one(struct pci_dev *dev)
-{
-	kfree(dev->ats);
-	dev->ats = NULL;
+	dev->ats_cap = pos;
 }
 
 /**
@@ -56,43 +37,36 @@ static void ats_free_one(struct pci_dev *dev)
  */
 int pci_enable_ats(struct pci_dev *dev, int ps)
 {
-	int rc;
 	u16 ctrl;
+	struct pci_dev *pdev;
 
-	BUG_ON(dev->ats && dev->ats->is_enabled);
-
-	if (ps < PCI_ATS_MIN_STU)
+	if (!dev->ats_cap)
 		return -EINVAL;
 
-	if (dev->is_physfn || dev->is_virtfn) {
-		struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;
-
-		mutex_lock(&pdev->sriov->lock);
-		if (pdev->ats)
-			rc = pdev->ats->stu == ps ? 0 : -EINVAL;
-		else
-			rc = ats_alloc_one(pdev, ps);
-
-		if (!rc)
-			pdev->ats->ref_cnt++;
-		mutex_unlock(&pdev->sriov->lock);
-		if (rc)
-			return rc;
-	}
+	if (WARN_ON(dev->ats_enabled))
+		return -EBUSY;
 
-	if (!dev->is_physfn) {
-		rc = ats_alloc_one(dev, ps);
-		if (rc)
-			return rc;
-	}
+	if (ps < PCI_ATS_MIN_STU)
+		return -EINVAL;
 
+	/*
+	 * Note that enabling ATS on a VF fails unless it's already enabled
+	 * with the same STU on the PF.
+	 */
 	ctrl = PCI_ATS_CTRL_ENABLE;
-	if (!dev->is_virtfn)
-		ctrl |= PCI_ATS_CTRL_STU(ps - PCI_ATS_MIN_STU);
-	pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
-
-	dev->ats->is_enabled = 1;
+	if (dev->is_virtfn) {
+		pdev = pci_physfn(dev);
+		if (pdev->ats_stu != ps)
+			return -EINVAL;
+
+		atomic_inc(&pdev->ats_ref_cnt);  /* count enabled VFs */
+	} else {
+		dev->ats_stu = ps;
+		ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU);
+	}
+	pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
 
+	dev->ats_enabled = 1;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pci_enable_ats);
@@ -103,28 +77,25 @@ EXPORT_SYMBOL_GPL(pci_enable_ats);
  */
 void pci_disable_ats(struct pci_dev *dev)
 {
+	struct pci_dev *pdev;
 	u16 ctrl;
 
-	BUG_ON(!dev->ats || !dev->ats->is_enabled);
-
-	pci_read_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, &ctrl);
-	ctrl &= ~PCI_ATS_CTRL_ENABLE;
-	pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
-
-	dev->ats->is_enabled = 0;
+	if (WARN_ON(!dev->ats_enabled))
+		return;
 
-	if (dev->is_physfn || dev->is_virtfn) {
-		struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;
+	if (atomic_read(&dev->ats_ref_cnt))
+		return;		/* VFs still enabled */
 
-		mutex_lock(&pdev->sriov->lock);
-		pdev->ats->ref_cnt--;
-		if (!pdev->ats->ref_cnt)
-			ats_free_one(pdev);
-		mutex_unlock(&pdev->sriov->lock);
+	if (dev->is_virtfn) {
+		pdev = pci_physfn(dev);
+		atomic_dec(&pdev->ats_ref_cnt);
 	}
 
-	if (!dev->is_physfn)
-		ats_free_one(dev);
+	pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, &ctrl);
+	ctrl &= ~PCI_ATS_CTRL_ENABLE;
+	pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
+
+	dev->ats_enabled = 0;
 }
 EXPORT_SYMBOL_GPL(pci_disable_ats);
 
@@ -132,16 +103,13 @@ void pci_restore_ats_state(struct pci_dev *dev)
 {
 	u16 ctrl;
 
-	if (!pci_ats_enabled(dev))
+	if (!dev->ats_enabled)
 		return;
-	if (!pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS))
-		BUG();
 
 	ctrl = PCI_ATS_CTRL_ENABLE;
 	if (!dev->is_virtfn)
-		ctrl |= PCI_ATS_CTRL_STU(dev->ats->stu - PCI_ATS_MIN_STU);
-
-	pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
+		ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU);
+	pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
 }
 EXPORT_SYMBOL_GPL(pci_restore_ats_state);
 
@@ -159,23 +127,16 @@ EXPORT_SYMBOL_GPL(pci_restore_ats_state);
  */
 int pci_ats_queue_depth(struct pci_dev *dev)
 {
-	int pos;
 	u16 cap;
 
+	if (!dev->ats_cap)
+		return -EINVAL;
+
 	if (dev->is_virtfn)
 		return 0;
 
-	if (dev->ats)
-		return dev->ats->qdep;
-
-	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
-	if (!pos)
-		return -ENODEV;
-
-	pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap);
-
-	return PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
-				       PCI_ATS_MAX_QDEP;
+	pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CAP, &cap);
+	return PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) : PCI_ATS_MAX_QDEP;
 }
 EXPORT_SYMBOL_GPL(pci_ats_queue_depth);