From: "David E. Box" <david.e.box@xxxxxxxxxxxxxxx> The Latency Tolerance Reporting (LTR) mechanism supports the ASPM L1.2 state and is only configured when CONFIG_PCIEASPM is set. Move pci_configure_ltr() and pci_bridge_reconfigure_ltr() into aspm.c since they only build when CONFIG_PCIEASPM is set. No functional change intended. Suggested-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240128233212.1139663-2-david.e.box@xxxxxxxxxxxxxxx Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx> [bhelgaas: commit log, split build change from function moves] Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> --- drivers/pci/pci.c | 18 ---------- drivers/pci/pci.h | 5 ++- drivers/pci/pcie/aspm.c | 75 +++++++++++++++++++++++++++++++++++++++++ drivers/pci/probe.c | 61 --------------------------------- 4 files changed, 79 insertions(+), 80 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index d8f11a078924..c783e0f1f2a9 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1626,24 +1626,6 @@ static int pci_save_pcie_state(struct pci_dev *dev) return 0; } -void pci_bridge_reconfigure_ltr(struct pci_dev *dev) -{ -#ifdef CONFIG_PCIEASPM - struct pci_dev *bridge; - u32 ctl; - - bridge = pci_upstream_bridge(dev); - if (bridge && bridge->ltr_path) { - pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2, &ctl); - if (!(ctl & PCI_EXP_DEVCTL2_LTR_EN)) { - pci_dbg(bridge, "re-enabling LTR\n"); - pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2, - PCI_EXP_DEVCTL2_LTR_EN); - } - } -#endif -} - static void pci_restore_pcie_state(struct pci_dev *dev) { int i = 0; diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 2336a8d1edab..9aeba82facc4 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -97,7 +97,6 @@ void pci_msi_init(struct pci_dev *dev); void pci_msix_init(struct pci_dev *dev); bool pci_bridge_d3_possible(struct pci_dev *dev); void pci_bridge_d3_update(struct pci_dev *dev); -void pci_bridge_reconfigure_ltr(struct pci_dev *dev); int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type); static inline void pci_wakeup_event(struct pci_dev *dev) @@ -573,11 +572,15 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev); void pcie_aspm_exit_link_state(struct pci_dev *pdev); void pcie_aspm_pm_state_change(struct pci_dev *pdev); void pcie_aspm_powersave_config_link(struct pci_dev *pdev); +void pci_configure_ltr(struct pci_dev *pdev); +void pci_bridge_reconfigure_ltr(struct pci_dev *pdev); #else static inline void pcie_aspm_init_link_state(struct pci_dev *pdev) { } static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev) { } static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev) { } static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) { } +static inline void pci_configure_ltr(struct pci_dev *pdev) { } +static inline void pci_bridge_reconfigure_ltr(struct pci_dev *pdev) { } #endif #ifdef CONFIG_PCIE_ECRC diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 5a0066ecc3c5..d1538f73f2f9 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -938,6 +938,81 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) up_read(&pci_bus_sem); } +void pci_bridge_reconfigure_ltr(struct pci_dev *pdev) +{ + struct pci_dev *bridge; + u32 ctl; + + bridge = pci_upstream_bridge(pdev); + if (bridge && bridge->ltr_path) { + pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2, &ctl); + if (!(ctl & PCI_EXP_DEVCTL2_LTR_EN)) { + pci_dbg(bridge, "re-enabling LTR\n"); + pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2, + PCI_EXP_DEVCTL2_LTR_EN); + } + } +} + +void pci_configure_ltr(struct pci_dev *pdev) +{ + struct pci_host_bridge *host = pci_find_host_bridge(pdev->bus); + struct pci_dev *bridge; + u32 cap, ctl; + + if (!pci_is_pcie(pdev)) + return; + + /* Read L1 PM substate capabilities */ + pdev->l1ss = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_L1SS); + + pcie_capability_read_dword(pdev, PCI_EXP_DEVCAP2, &cap); + if (!(cap & PCI_EXP_DEVCAP2_LTR)) + return; + + pcie_capability_read_dword(pdev, PCI_EXP_DEVCTL2, &ctl); + if (ctl & PCI_EXP_DEVCTL2_LTR_EN) { + if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT) { + pdev->ltr_path = 1; + return; + } + + bridge = pci_upstream_bridge(pdev); + if (bridge && bridge->ltr_path) + pdev->ltr_path = 1; + + return; + } + + if (!host->native_ltr) + return; + + /* + * Software must not enable LTR in an Endpoint unless the Root + * Complex and all intermediate Switches indicate support for LTR. + * PCIe r4.0, sec 6.18. + */ + if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT) { + pcie_capability_set_word(pdev, PCI_EXP_DEVCTL2, + PCI_EXP_DEVCTL2_LTR_EN); + pdev->ltr_path = 1; + return; + } + + /* + * If we're configuring a hot-added device, LTR was likely + * disabled in the upstream bridge, so re-enable it before enabling + * it in the new device. + */ + bridge = pci_upstream_bridge(pdev); + if (bridge && bridge->ltr_path) { + pci_bridge_reconfigure_ltr(pdev); + pcie_capability_set_word(pdev, PCI_EXP_DEVCTL2, + PCI_EXP_DEVCTL2_LTR_EN); + pdev->ltr_path = 1; + } +} + /* Recheck latencies and update aspm_capable for links under the root */ static void pcie_update_aspm_capable(struct pcie_link_state *root) { diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index b7335be56008..b809c0b0e0e5 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2209,67 +2209,6 @@ static void pci_configure_relaxed_ordering(struct pci_dev *dev) } } -static void pci_configure_ltr(struct pci_dev *dev) -{ -#ifdef CONFIG_PCIEASPM - struct pci_host_bridge *host = pci_find_host_bridge(dev->bus); - struct pci_dev *bridge; - u32 cap, ctl; - - if (!pci_is_pcie(dev)) - return; - - /* Read L1 PM substate capabilities */ - dev->l1ss = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_L1SS); - - pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap); - if (!(cap & PCI_EXP_DEVCAP2_LTR)) - return; - - pcie_capability_read_dword(dev, PCI_EXP_DEVCTL2, &ctl); - if (ctl & PCI_EXP_DEVCTL2_LTR_EN) { - if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) { - dev->ltr_path = 1; - return; - } - - bridge = pci_upstream_bridge(dev); - if (bridge && bridge->ltr_path) - dev->ltr_path = 1; - - return; - } - - if (!host->native_ltr) - return; - - /* - * Software must not enable LTR in an Endpoint unless the Root - * Complex and all intermediate Switches indicate support for LTR. - * PCIe r4.0, sec 6.18. - */ - if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) { - pcie_capability_set_word(dev, PCI_EXP_DEVCTL2, - PCI_EXP_DEVCTL2_LTR_EN); - dev->ltr_path = 1; - return; - } - - /* - * If we're configuring a hot-added device, LTR was likely - * disabled in the upstream bridge, so re-enable it before enabling - * it in the new device. - */ - bridge = pci_upstream_bridge(dev); - if (bridge && bridge->ltr_path) { - pci_bridge_reconfigure_ltr(dev); - pcie_capability_set_word(dev, PCI_EXP_DEVCTL2, - PCI_EXP_DEVCTL2_LTR_EN); - dev->ltr_path = 1; - } -#endif -} - static void pci_configure_eetlp_prefix(struct pci_dev *dev) { #ifdef CONFIG_PCI_PASID -- 2.34.1
