From: Kuppuswamy Sathyanarayanan <[email protected]>
Currently all VF's needs to be disable their ATS service before disabling the ATS service in corresponding PF device. But this logic is incorrect and does not align with the spec. Also it might lead to some power and performance impact in the system. As per PCIe spec r4.0, sec 9.3.7.8, ATS Capabilities in VFs and their associated PFs may be enabled/disabled independently. 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 13fe88829306..8ee2c1123b84 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -140,8 +140,6 @@ 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); @@ -159,20 +157,11 @@ 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 a317c3115d69..442ced0d2dd1 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -449,7 +449,6 @@ 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 struct mutex pri_lock; /* PRI enable lock */ -- 2.21.0
