From: Kuppuswamy Sathyanarayanan <[email protected]>

As per PCIe spec r4.0, sec 9.3.7.8, ATS Capabilities in VFs and their
associated PFs may be enabled independently. But currently all VFs needs
to disable ATS service before disabling the ATS service in PF. So remove
this dependency logic in enable/disable code.

Cc: Ashok Raj <[email protected]>
Cc: Keith Busch <[email protected]>
Suggested-by: Ashok Raj <[email protected]>
Signed-off-by: Kuppuswamy Sathyanarayanan 
<[email protected]>
---
 drivers/pci/ats.c   | 11 -----------
 include/linux/pci.h |  1 -
 2 files changed, 12 deletions(-)

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index 11299d93a59a..062471abfeca 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -66,8 +66,6 @@ int pci_enable_ats(struct pci_dev *dev, int ps)
                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);
@@ -85,20 +83,11 @@ EXPORT_SYMBOL_GPL(pci_enable_ats);
  */
 void pci_disable_ats(struct pci_dev *dev)
 {
-       struct pci_dev *pdev;
        u16 ctrl;
 
        if (WARN_ON(!dev->ats_enabled))
                return;
 
-       if (atomic_read(&dev->ats_ref_cnt))
-               return;         /* VFs still enabled */
-
-       if (dev->is_virtfn) {
-               pdev = pci_physfn(dev);
-               atomic_dec(&pdev->ats_ref_cnt);
-       }
-
        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);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c6c413c52403..07e796e7f2bf 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -444,7 +444,6 @@ struct pci_dev {
        };
        u16             ats_cap;        /* ATS Capability offset */
        u8              ats_stu;        /* ATS Smallest Translation Unit */
-       atomic_t        ats_ref_cnt;    /* Number of VFs with ATS enabled */
 #endif
 #ifdef CONFIG_PCI_PRI
        u32             pri_reqs_alloc; /* Number of PRI requests allocated */
-- 
2.20.1

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