PCI: handle Virtual Function ATS enabling
The SR-IOV spec requires that the Smallest Translation Unit and
the Invalidate Queue Depth fields in the Virtual Function ATS
capability are hardwired to 0. If a function is a Virtual Function,
then and set its Physical Function's STU before enabling the ATS.
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 0a7a1b4..4151404 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -491,10 +491,10 @@
if (pdev)
iov->dev = pci_dev_get(pdev);
- else {
+ else
iov->dev = dev;
- mutex_init(&iov->lock);
- }
+
+ mutex_init(&iov->lock);
dev->sriov = iov;
dev->is_physfn = 1;
@@ -514,11 +514,11 @@
{
BUG_ON(dev->sriov->nr_virtfn);
- if (dev == dev->sriov->dev)
- mutex_destroy(&dev->sriov->lock);
- else
+ if (dev != dev->sriov->dev)
pci_dev_put(dev->sriov->dev);
+ mutex_destroy(&dev->sriov->lock);
+
kfree(dev->sriov);
dev->sriov = NULL;
}
@@ -723,19 +723,40 @@
int rc;
u16 ctrl;
- BUG_ON(dev->ats);
+ BUG_ON(dev->ats && dev->ats->is_enabled);
if (ps < PCI_ATS_MIN_STU)
return -EINVAL;
- rc = ats_alloc_one(dev, ps);
- if (rc)
- return rc;
+ 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 (!dev->is_physfn) {
+ rc = ats_alloc_one(dev, ps);
+ if (rc)
+ return rc;
+ }
ctrl = PCI_ATS_CTRL_ENABLE;
- ctrl |= PCI_ATS_CTRL_STU(ps - PCI_ATS_MIN_STU);
+ 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;
+
return 0;
}
@@ -747,13 +768,26 @@
{
u16 ctrl;
- BUG_ON(!dev->ats);
+ 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);
- ats_free_one(dev);
+ dev->ats->is_enabled = 0;
+
+ if (dev->is_physfn || dev->is_virtfn) {
+ struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;
+
+ 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_physfn)
+ ats_free_one(dev);
}
/**
@@ -765,13 +799,17 @@
* The ATS spec uses 0 in the Invalidate Queue Depth field to
* indicate that the function can accept 32 Invalidate Request.
* But here we use the `real' values (i.e. 1~32) for the Queue
- * Depth.
+ * Depth; and 0 indicates the function shares the Queue with
+ * other functions (doesn't exclusively own a Queue).
*/
int pci_ats_queue_depth(struct pci_dev *dev)
{
int pos;
u16 cap;
+ if (dev->is_virtfn)
+ return 0;
+
if (dev->ats)
return dev->ats->qdep;
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 3c2ec64..f73bcbe 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -234,6 +234,8 @@
int pos; /* capability position */
int stu; /* Smallest Translation Unit */
int qdep; /* Invalidate Queue Depth */
+ int ref_cnt; /* Physical Function reference count */
+ int is_enabled:1; /* Enable bit is set */
};
#ifdef CONFIG_PCI_IOV
@@ -255,7 +257,7 @@
*/
static inline int pci_ats_enabled(struct pci_dev *dev)
{
- return !!dev->ats;
+ return dev->ats && dev->ats->is_enabled;
}
#else
static inline int pci_iov_init(struct pci_dev *dev)