From: Kuppuswamy Sathyanarayanan <[email protected]>
Currently, PASID Capability checks are repeated across all PASID API's. Instead, cache the capability check result in pci_pasid_init() and use it in other PASID API's. Also, since PASID is a shared resource between PF/VF, initialize PASID features with default values in pci_pasid_init(). Signed-off-by: Kuppuswamy Sathyanarayanan <[email protected]> --- drivers/pci/ats.c | 76 ++++++++++++++++++++++++++++++++------------- include/linux/pci.h | 1 + 2 files changed, 56 insertions(+), 21 deletions(-) diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index a14ab20f1c28..b5ce40c54e0b 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -50,6 +50,41 @@ static void pci_pri_init(struct pci_dev *pdev) } #endif +#ifdef CONFIG_PCI_PASID +static void pci_pasid_init(struct pci_dev *pdev) +{ + u16 supported; + int pos; + + /* + * As per PCIe r4.0, sec 9.3.7.14, only PF is permitted to + * implement PASID Capability and all associated VFs can + * only use it. Since PF already initialized the PASID + * parameters there is no need to proceed further. + */ + if (pdev->is_virtfn) + return; + + pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID); + if (!pos) + return; + + pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported); + + supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV; + + /* + * Enable all supported features. Since PASID is a shared + * resource between PF/VF, we must not set this feature as + * a per device property in pci_enable_pasid(). + */ + pci_write_config_word(pdev, pos + PCI_PASID_CTRL, supported); + + pdev->pasid_features = supported; + pdev->pasid_cap = pos; +} +#endif + void pci_ats_init(struct pci_dev *dev) { int pos; @@ -66,6 +101,9 @@ void pci_ats_init(struct pci_dev *dev) #ifdef CONFIG_PCI_PRI pci_pri_init(dev); #endif +#ifdef CONFIG_PCI_PASID + pci_pasid_init(dev); +#endif } /** @@ -326,11 +364,13 @@ EXPORT_SYMBOL_GPL(pci_reset_pri); * Returns 0 on success, negative value on error. This function checks * whether the features are actually supported by the device and returns * an error if not. + * + * TODO: Since PASID is a shared resource between PF/VF, don't update + * PASID features in the same API as a per device feature. */ int pci_enable_pasid(struct pci_dev *pdev, int features) { u16 control, supported; - int pos; if (WARN_ON(pdev->pasid_enabled)) return -EBUSY; @@ -338,11 +378,11 @@ 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) + if (!pdev->pasid_cap) return -EINVAL; - pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported); + pci_read_config_word(pdev, pdev->pasid_cap + PCI_PASID_CAP, + &supported); supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV; /* User wants to enable anything unsupported? */ @@ -352,7 +392,7 @@ 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, pdev->pasid_cap + PCI_PASID_CTRL, control); pdev->pasid_enabled = 1; @@ -367,16 +407,14 @@ EXPORT_SYMBOL_GPL(pci_enable_pasid); void pci_disable_pasid(struct pci_dev *pdev) { u16 control = 0; - int pos; if (WARN_ON(!pdev->pasid_enabled)) return; - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID); - if (!pos) + if (!pdev->pasid_cap) return; - pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control); + pci_write_config_word(pdev, pdev->pasid_cap + PCI_PASID_CTRL, control); pdev->pasid_enabled = 0; } @@ -389,17 +427,15 @@ EXPORT_SYMBOL_GPL(pci_disable_pasid); void pci_restore_pasid_state(struct pci_dev *pdev) { u16 control; - int pos; if (!pdev->pasid_enabled) return; - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID); - if (!pos) + if (!pdev->pasid_cap) return; control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features; - pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control); + pci_write_config_word(pdev, pdev->pasid_cap + PCI_PASID_CTRL, control); } EXPORT_SYMBOL_GPL(pci_restore_pasid_state); @@ -416,13 +452,12 @@ EXPORT_SYMBOL_GPL(pci_restore_pasid_state); int pci_pasid_features(struct pci_dev *pdev) { u16 supported; - int pos; - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID); - if (!pos) + if (!pdev->pasid_cap) return -EINVAL; - pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported); + pci_read_config_word(pdev, pdev->pasid_cap + PCI_PASID_CAP, + &supported); supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV; @@ -472,13 +507,12 @@ EXPORT_SYMBOL_GPL(pci_prg_resp_pasid_required); int pci_max_pasids(struct pci_dev *pdev) { u16 supported; - int pos; - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID); - if (!pos) + if (!pdev->pasid_cap) return -EINVAL; - pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported); + pci_read_config_word(pdev, pdev->pasid_cap + 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 f3fe625bc8bb..b4010276dff6 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -456,6 +456,7 @@ 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 -- 2.21.0
