From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> Previously each PASID interface searched for the PASID Capability. Cache the capability offset the first time we use it instead of searching each time. [bhelgaas: commit log, reorder patch to later, save offset directly in pci_enable_pasid() rather than adding pci_pasid_init()] Link: https://lore.kernel.org/r/4957778959fa34eab3e8b3065d1951989c61cb0f.1567029860.git.sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> --- drivers/pci/ats.c | 43 +++++++++++++++++++++---------------------- include/linux/pci.h | 1 + 2 files changed, 22 insertions(+), 22 deletions(-) diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index bc463e2ecc61..cb4f62da7b8a 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -305,7 +305,7 @@ EXPORT_SYMBOL_GPL(pci_reset_pri); int pci_enable_pasid(struct pci_dev *pdev, int features) { u16 control, supported; - int pos; + int pasid = pdev->pasid_cap; /* * VFs must not implement the PASID Capability, but if a PF @@ -323,11 +323,14 @@ int pci_enable_pasid(struct pci_dev *pdev, int features) if (!pdev->eetlp_prefix_path) return -EINVAL; - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID); - if (!pos) - return -EINVAL; + if (!pasid) { + pasid = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID); + if (!pasid) + return -EINVAL; + pdev->pasid_cap = pasid; + } - pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported); + pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported); supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV; /* User wants to enable anything unsupported? */ @@ -337,7 +340,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features) control = PCI_PASID_CTRL_ENABLE | features; pdev->pasid_features = features; - pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control); + pci_write_config_word(pdev, pasid + PCI_PASID_CTRL, control); pdev->pasid_enabled = 1; @@ -352,7 +355,7 @@ EXPORT_SYMBOL_GPL(pci_enable_pasid); void pci_disable_pasid(struct pci_dev *pdev) { u16 control = 0; - int pos; + int pasid = pdev->pasid_cap; /* VFs share the PF PASID configuration */ if (pdev->is_virtfn) @@ -361,11 +364,10 @@ void pci_disable_pasid(struct pci_dev *pdev) if (WARN_ON(!pdev->pasid_enabled)) return; - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID); - if (!pos) + if (!pasid) return; - pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control); + pci_write_config_word(pdev, pasid + PCI_PASID_CTRL, control); pdev->pasid_enabled = 0; } @@ -378,7 +380,7 @@ EXPORT_SYMBOL_GPL(pci_disable_pasid); void pci_restore_pasid_state(struct pci_dev *pdev) { u16 control; - int pos; + int pasid = pdev->pasid_cap; if (pdev->is_virtfn) return; @@ -386,12 +388,11 @@ void pci_restore_pasid_state(struct pci_dev *pdev) if (!pdev->pasid_enabled) return; - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID); - if (!pos) + if (!pasid) return; control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features; - pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control); + pci_write_config_word(pdev, pasid + PCI_PASID_CTRL, control); } EXPORT_SYMBOL_GPL(pci_restore_pasid_state); @@ -408,16 +409,15 @@ EXPORT_SYMBOL_GPL(pci_restore_pasid_state); int pci_pasid_features(struct pci_dev *pdev) { u16 supported; - int pos; + int pasid = pdev->pasid_cap; if (pdev->is_virtfn) pdev = pci_physfn(pdev); - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID); - if (!pos) + if (!pasid) return -EINVAL; - pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported); + pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported); supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV; @@ -470,16 +470,15 @@ EXPORT_SYMBOL_GPL(pci_prg_resp_pasid_required); int pci_max_pasids(struct pci_dev *pdev) { u16 supported; - int pos; + int pasid = pdev->pasid_cap; if (pdev->is_virtfn) pdev = pci_physfn(pdev); - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID); - if (!pos) + if (!pasid) return -EINVAL; - pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported); + pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported); supported = (supported & PASID_NUMBER_MASK) >> PASID_NUMBER_SHIFT; diff --git a/include/linux/pci.h b/include/linux/pci.h index c81a24172b14..7ddbb6445e1a 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -458,6 +458,7 @@ struct pci_dev { u32 pri_reqs_alloc; /* Number of PRI requests allocated */ #endif #ifdef CONFIG_PCI_PASID + u16 pasid_cap; /* PASID Capability offset */ u16 pasid_features; #endif #ifdef CONFIG_PCI_P2PDMA -- 2.23.0.187.g17f5b7556c-goog
