From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> Previously each PRI interface searched for the PRI 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_pri() rather than adding pci_pri_init()] Link: https://lore.kernel.org/r/0c5495d376faf6dbb8eb2165204c474438aaae65.156 7029860.git.sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> --- drivers/pci/ats.c | 52 ++++++++++++++++++++++----------------------- include/linux/pci.h | 1 + 2 files changed, 27 insertions(+), 26 deletions(-) diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index 920deeccf38d..bc463e2ecc61 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -169,7 +169,7 @@ int pci_enable_pri(struct pci_dev *pdev, u32 reqs) { u16 control, status; u32 max_requests; - int pos; + int pri = pdev->pri_cap; /* * VFs must not implement the PRI Capability. If their PF @@ -185,21 +185,24 @@ int pci_enable_pri(struct pci_dev *pdev, u32 reqs) if (WARN_ON(pdev->pri_enabled)) return -EBUSY; - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI); - if (!pos) - return -EINVAL; + if (!pri) { + pri = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI); + if (!pri) + return -EINVAL; + pdev->pri_cap = pri; + } - pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status); + pci_read_config_word(pdev, pri + PCI_PRI_STATUS, &status); if (!(status & PCI_PRI_STATUS_STOPPED)) return -EBUSY; - pci_read_config_dword(pdev, pos + PCI_PRI_MAX_REQ, &max_requests); + pci_read_config_dword(pdev, pri + PCI_PRI_MAX_REQ, &max_requests); reqs = min(max_requests, reqs); pdev->pri_reqs_alloc = reqs; - pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs); + pci_write_config_dword(pdev, pri + PCI_PRI_ALLOC_REQ, reqs); control = PCI_PRI_CTRL_ENABLE; - pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control); + pci_write_config_word(pdev, pri + PCI_PRI_CTRL, control); pdev->pri_enabled = 1; @@ -216,7 +219,7 @@ EXPORT_SYMBOL_GPL(pci_enable_pri); void pci_disable_pri(struct pci_dev *pdev) { u16 control; - int pos; + int pri = pdev->pri_cap; /* VFs share the PF PRI */ if (pdev->is_virtfn) @@ -225,13 +228,12 @@ void pci_disable_pri(struct pci_dev *pdev) if (WARN_ON(!pdev->pri_enabled)) return; - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI); - if (!pos) + if (!pri) return; - pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control); + pci_read_config_word(pdev, pri + PCI_PRI_CTRL, &control); control &= ~PCI_PRI_CTRL_ENABLE; - pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control); + pci_write_config_word(pdev, pri + PCI_PRI_CTRL, control); pdev->pri_enabled = 0; } @@ -245,7 +247,7 @@ void pci_restore_pri_state(struct pci_dev *pdev) { u16 control = PCI_PRI_CTRL_ENABLE; u32 reqs = pdev->pri_reqs_alloc; - int pos; + int pri = pdev->pri_cap; if (pdev->is_virtfn) return; @@ -253,12 +255,11 @@ void pci_restore_pri_state(struct pci_dev *pdev) if (!pdev->pri_enabled) return; - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI); - if (!pos) + if (!pri) return; - pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs); - pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control); + pci_write_config_dword(pdev, pri + PCI_PRI_ALLOC_REQ, reqs); + pci_write_config_word(pdev, pri + PCI_PRI_CTRL, control); } EXPORT_SYMBOL_GPL(pci_restore_pri_state); @@ -272,7 +273,7 @@ EXPORT_SYMBOL_GPL(pci_restore_pri_state); int pci_reset_pri(struct pci_dev *pdev) { u16 control; - int pos; + int pri = pdev->pri_cap; if (pdev->is_virtfn) return 0; @@ -280,12 +281,11 @@ int pci_reset_pri(struct pci_dev *pdev) if (WARN_ON(pdev->pri_enabled)) return -EBUSY; - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI); - if (!pos) + if (!pri) return -EINVAL; control = PCI_PRI_CTRL_RESET; - pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control); + pci_write_config_word(pdev, pri + PCI_PRI_CTRL, control); return 0; } @@ -440,16 +440,16 @@ EXPORT_SYMBOL_GPL(pci_pasid_features); int pci_prg_resp_pasid_required(struct pci_dev *pdev) { u16 status; - int pos; + int pri; if (pdev->is_virtfn) pdev = pci_physfn(pdev); - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI); - if (!pos) + pri = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI); + if (!pri) return 0; - pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status); + pci_read_config_word(pdev, pri + PCI_PRI_STATUS, &status); if (status & PCI_PRI_STATUS_PASID) return 1; diff --git a/include/linux/pci.h b/include/linux/pci.h index a73e8d28a896..c81a24172b14 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -454,6 +454,7 @@ struct pci_dev { u8 ats_stu; /* ATS Smallest Translation Unit */ #endif #ifdef CONFIG_PCI_PRI + u16 pri_cap; /* PRI Capability offset */ u32 pri_reqs_alloc; /* Number of PRI requests allocated */ #endif #ifdef CONFIG_PCI_PASID -- 2.23.0.187.g17f5b7556c-goog
