PCI: Stop caching ATS Invalidate Queue Depth

Stop caching the Invalidate Queue Depth in struct pci_dev.
pci_ats_queue_depth() is typically called only once per device, and it
returns a fixed value per-device, so callers who need the value frequently
can cache it themselves.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 4 insertions, 5 deletions

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index 9355f754c7c2..ceda7dc556d4 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -20,16 +20,12 @@
 void pci_ats_init(struct pci_dev *dev)
 {
         int pos;
-        u16 cap;
 
         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
         if (!pos)
                 return;
 
         dev->ats_cap = pos;
-        pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CAP, &cap);
-        dev->ats_qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
-                                            PCI_ATS_MAX_QDEP;
 }
 
 /**
@@ -131,13 +127,16 @@ EXPORT_SYMBOL_GPL(pci_restore_ats_state);
  */
 int pci_ats_queue_depth(struct pci_dev *dev)
 {
+        u16 cap;
+
         if (!dev->ats_cap)
                 return -EINVAL;
 
         if (dev->is_virtfn)
                 return 0;
 
-        return dev->ats_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);