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>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 3c2ec64f78e9..f73bcbedf37c 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -234,6 +234,8 @@ struct pci_ats {
         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 @@ extern int pci_ats_queue_depth(struct pci_dev *dev);
  */
 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)