From fa84f4435a6202dd90248517f41e54bf3fb85bc5 Mon Sep 17 00:00:00 2001 From: "David E. Box" Date: Fri, 23 Feb 2024 14:58:47 -0600 Subject: PCI/ASPM: Move pci_configure_ltr() to aspm.c 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 Link: https://lore.kernel.org/r/20240128233212.1139663-2-david.e.box@linux.intel.com [bhelgaas: commit log, split build change from function moves] Link: https://lore.kernel.org/r/20240223205851.114931-2-helgaas@kernel.org Signed-off-by: David E. Box Signed-off-by: Bjorn Helgaas --- 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(-) (limited to 'drivers/pci') 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 @@ out: 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 -- cgit From f3994bba8200b49e3eacbe5914cd13f228e0db37 Mon Sep 17 00:00:00 2001 From: "David E. Box" Date: Fri, 23 Feb 2024 14:58:48 -0600 Subject: PCI/ASPM: Always build aspm.c Some ASPM-related tasks, such as save and restore of LTR and L1SS capabilities, still need to be performed when CONFIG_PCIEASPM is not enabled. To prepare for these changes, wrap the current code in aspm.c with an #ifdef and always build the file. Link: https://lore.kernel.org/r/20240128233212.1139663-2-david.e.box@linux.intel.com [bhelgaas: split build change from function moves] Link: https://lore.kernel.org/r/20240223205851.114931-3-helgaas@kernel.org Signed-off-by: David E. Box Signed-off-by: Bjorn Helgaas --- drivers/pci/pcie/Makefile | 2 +- drivers/pci/pcie/aspm.c | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile index 8de4ed5f98f1..6461aa93fe76 100644 --- a/drivers/pci/pcie/Makefile +++ b/drivers/pci/pcie/Makefile @@ -6,7 +6,7 @@ pcieportdrv-y := portdrv.o rcec.o obj-$(CONFIG_PCIEPORTBUS) += pcieportdrv.o -obj-$(CONFIG_PCIEASPM) += aspm.o +obj-y += aspm.o obj-$(CONFIG_PCIEAER) += aer.o err.o obj-$(CONFIG_PCIEAER_INJECT) += aer_inject.o obj-$(CONFIG_PCIE_PME) += pme.o diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index d1538f73f2f9..d50c0f83430f 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -24,6 +24,8 @@ #include "../pci.h" +#ifdef CONFIG_PCIEASPM + #ifdef MODULE_PARAM_PREFIX #undef MODULE_PARAM_PREFIX #endif @@ -1517,3 +1519,5 @@ bool pcie_aspm_support_enabled(void) { return aspm_support_enabled; } + +#endif /* CONFIG_PCIEASPM */ -- cgit From 1e11b5494c3dbb1e5fce7e95021c1698799c7288 Mon Sep 17 00:00:00 2001 From: "David E. Box" Date: Fri, 23 Feb 2024 14:58:49 -0600 Subject: PCI/ASPM: Move pci_save_ltr_state() to aspm.c Even when CONFIG_PCIEASPM is not set, we save and restore the LTR Capability so that if ASPM L1.2 and LTR were configured by the platform, ASPM L1.2 will still work after suspend/resume, when that platform configuration may be lost. See dbbfadf23190 ("PCI/ASPM: Save LTR Capability for suspend/resume"). Since ASPM L1.2 depends on the LTR Capability, move the save/restore code to the part of aspm.c that is always compiled regardless of CONFIG_PCIEASPM. No functional change intended. Suggested-by: Bjorn Helgaas Link: https://lore.kernel.org/r/20240128233212.1139663-5-david.e.box@linux.intel.com [bhelgaas: commit log, reorder to make this a pure move] Link: https://lore.kernel.org/r/20240223205851.114931-4-helgaas@kernel.org Signed-off-by: David E. Box Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 40 ---------------------------------------- drivers/pci/pci.h | 5 +++++ drivers/pci/pcie/aspm.c | 40 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 45 insertions(+), 40 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index c783e0f1f2a9..564e2cf2dde5 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1689,46 +1689,6 @@ static void pci_restore_pcix_state(struct pci_dev *dev) pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]); } -static void pci_save_ltr_state(struct pci_dev *dev) -{ - int ltr; - struct pci_cap_saved_state *save_state; - u32 *cap; - - if (!pci_is_pcie(dev)) - return; - - ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); - if (!ltr) - return; - - save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR); - if (!save_state) { - pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n"); - return; - } - - /* Some broken devices only support dword access to LTR */ - cap = &save_state->cap.data[0]; - pci_read_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap); -} - -static void pci_restore_ltr_state(struct pci_dev *dev) -{ - struct pci_cap_saved_state *save_state; - int ltr; - u32 *cap; - - save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR); - ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); - if (!save_state || !ltr) - return; - - /* Some broken devices only support dword access to LTR */ - cap = &save_state->cap.data[0]; - pci_write_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap); -} - /** * pci_save_state - save the PCI configuration space of a device before * suspending diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 9aeba82facc4..ad3add45345c 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -567,6 +567,11 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, bool pcie_wait_for_link(struct pci_dev *pdev, bool active); int pcie_retrain_link(struct pci_dev *pdev, bool use_lt); + +/* ASPM-related functionality we need even without CONFIG_PCIEASPM */ +void pci_save_ltr_state(struct pci_dev *dev); +void pci_restore_ltr_state(struct pci_dev *dev); + #ifdef CONFIG_PCIEASPM void pcie_aspm_init_link_state(struct pci_dev *pdev); void pcie_aspm_exit_link_state(struct pci_dev *pdev); diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index d50c0f83430f..21731b232fb8 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -24,6 +24,46 @@ #include "../pci.h" +void pci_save_ltr_state(struct pci_dev *dev) +{ + int ltr; + struct pci_cap_saved_state *save_state; + u32 *cap; + + if (!pci_is_pcie(dev)) + return; + + ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); + if (!ltr) + return; + + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR); + if (!save_state) { + pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n"); + return; + } + + /* Some broken devices only support dword access to LTR */ + cap = &save_state->cap.data[0]; + pci_read_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap); +} + +void pci_restore_ltr_state(struct pci_dev *dev) +{ + struct pci_cap_saved_state *save_state; + int ltr; + u32 *cap; + + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR); + ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); + if (!save_state || !ltr) + return; + + /* Some broken devices only support dword access to LTR */ + cap = &save_state->cap.data[0]; + pci_write_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap); +} + #ifdef CONFIG_PCIEASPM #ifdef MODULE_PARAM_PREFIX -- cgit From 17423360a27ae58c1850f588bdd8013bbfcd250b Mon Sep 17 00:00:00 2001 From: "David E. Box" Date: Fri, 23 Feb 2024 14:58:50 -0600 Subject: PCI/ASPM: Save L1 PM Substates Capability for suspend/resume 4ff116d0d5fd ("PCI/ASPM: Save L1 PM Substates Capability for suspend/resume") restored the L1 PM Substates Capability after resume, which reduced power consumption by making the ASPM L1.x states work after resume. a7152be79b62 ("Revert "PCI/ASPM: Save L1 PM Substates Capability for suspend/resume"") reverted 4ff116d0d5fd because resume failed on some systems, so power consumption after resume increased again. a7152be79b62 mentioned that we restore L1 PM substate configuration even though ASPM L1 may already be enabled. This is due the fact that the pci_restore_aspm_l1ss_state() was called before pci_restore_pcie_state(). Save and restore the L1 PM Substates Capability, following PCIe r6.1, sec 5.5.4 more closely by: 1) Do not restore ASPM configuration in pci_restore_pcie_state() but do that after PCIe capability is restored in pci_restore_aspm_state() following PCIe r6.1, sec 5.5.4. 2) If BIOS reenables L1SS, particularly L1.2, we need to clear the enables in the right order, downstream before upstream. Defer restoring the L1SS config until we are at the downstream component. Then update the config for both ends of the link in the prescribed order. 3) Program ASPM L1 PM substate configuration before L1 enables. 4) Program ASPM L1 PM substate enables last, after rest of the fields in the capability are programmed. [bhelgaas: commit log, squash L1SS-related patches, do both LNKCTL restores in pci_restore_pcie_state()] Link: https://lore.kernel.org/r/20240128233212.1139663-3-david.e.box@linux.intel.com Link: https://lore.kernel.org/r/20240128233212.1139663-4-david.e.box@linux.intel.com Link: https://lore.kernel.org/r/20240223205851.114931-5-helgaas@kernel.org Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217321 Link: https://bugzilla.kernel.org/show_bug.cgi?id=216782 Link: https://bugzilla.kernel.org/show_bug.cgi?id=216877 Co-developed-by: Mika Westerberg Co-developed-by: David E. Box Reported-by: Koba Ko Signed-off-by: Mika Westerberg Signed-off-by: David E. Box Signed-off-by: Bjorn Helgaas Tested-by: Tasev Nikola # Asus UX305FA Cc: Mark Enriquez Cc: Thomas Witt Cc: Werner Sembach Cc: Vidya Sagar --- drivers/pci/pci.c | 17 +++++++- drivers/pci/pci.h | 3 ++ drivers/pci/pcie/aspm.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++-- drivers/pci/probe.c | 1 + 4 files changed, 118 insertions(+), 5 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 564e2cf2dde5..ca6673588bc0 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1623,6 +1623,8 @@ static int pci_save_pcie_state(struct pci_dev *dev) pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &cap[i++]); pcie_capability_read_word(dev, PCI_EXP_SLTCTL2, &cap[i++]); + pci_save_aspm_l1ss_state(dev); + return 0; } @@ -1630,7 +1632,7 @@ static void pci_restore_pcie_state(struct pci_dev *dev) { int i = 0; struct pci_cap_saved_state *save_state; - u16 *cap; + u16 *cap, lnkctl; save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP); if (!save_state) @@ -1645,12 +1647,23 @@ static void pci_restore_pcie_state(struct pci_dev *dev) cap = (u16 *)&save_state->cap.data[0]; pcie_capability_write_word(dev, PCI_EXP_DEVCTL, cap[i++]); - pcie_capability_write_word(dev, PCI_EXP_LNKCTL, cap[i++]); + + /* Restore LNKCTL register with ASPM control field clear */ + lnkctl = cap[i++]; + pcie_capability_write_word(dev, PCI_EXP_LNKCTL, + lnkctl & ~PCI_EXP_LNKCTL_ASPMC); + pcie_capability_write_word(dev, PCI_EXP_SLTCTL, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_RTCTL, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_DEVCTL2, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]); + + pci_restore_aspm_l1ss_state(dev); + + /* Restore ASPM control after restoring L1SS state */ + pcie_capability_set_word(dev, PCI_EXP_LNKCTL, + lnkctl & PCI_EXP_LNKCTL_ASPMC); } static int pci_save_pcix_state(struct pci_dev *dev) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index ad3add45345c..eca5938deb07 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -571,6 +571,9 @@ int pcie_retrain_link(struct pci_dev *pdev, bool use_lt); /* ASPM-related functionality we need even without CONFIG_PCIEASPM */ void pci_save_ltr_state(struct pci_dev *dev); void pci_restore_ltr_state(struct pci_dev *dev); +void pci_configure_aspm_l1ss(struct pci_dev *dev); +void pci_save_aspm_l1ss_state(struct pci_dev *dev); +void pci_restore_aspm_l1ss_state(struct pci_dev *dev); #ifdef CONFIG_PCIEASPM void pcie_aspm_init_link_state(struct pci_dev *pdev); diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 21731b232fb8..977eca893b2a 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -64,6 +64,105 @@ void pci_restore_ltr_state(struct pci_dev *dev) pci_write_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap); } +void pci_configure_aspm_l1ss(struct pci_dev *pdev) +{ + int rc; + + pdev->l1ss = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_L1SS); + + rc = pci_add_ext_cap_save_buffer(pdev, PCI_EXT_CAP_ID_L1SS, + 2 * sizeof(u32)); + if (rc) + pci_err(pdev, "unable to allocate ASPM L1SS save buffer (%pe)\n", + ERR_PTR(rc)); +} + +void pci_save_aspm_l1ss_state(struct pci_dev *pdev) +{ + struct pci_cap_saved_state *save_state; + u16 l1ss = pdev->l1ss; + u32 *cap; + + /* + * Save L1 substate configuration. The ASPM L0s/L1 configuration + * in PCI_EXP_LNKCTL_ASPMC is saved by pci_save_pcie_state(). + */ + if (!l1ss) + return; + + save_state = pci_find_saved_ext_cap(pdev, PCI_EXT_CAP_ID_L1SS); + if (!save_state) + return; + + cap = &save_state->cap.data[0]; + pci_read_config_dword(pdev, l1ss + PCI_L1SS_CTL2, cap++); + pci_read_config_dword(pdev, l1ss + PCI_L1SS_CTL1, cap++); +} + +void pci_restore_aspm_l1ss_state(struct pci_dev *pdev) +{ + struct pci_cap_saved_state *pl_save_state, *cl_save_state; + struct pci_dev *parent = pdev->bus->self; + u32 *cap, pl_ctl1, pl_ctl2, pl_l1_2_enable; + u32 cl_ctl1, cl_ctl2, cl_l1_2_enable; + + /* + * In case BIOS enabled L1.2 when resuming, we need to disable it first + * on the downstream component before the upstream. So, don't attempt to + * restore either until we are at the downstream component. + */ + if (pcie_downstream_port(pdev) || !parent) + return; + + if (!pdev->l1ss || !parent->l1ss) + return; + + cl_save_state = pci_find_saved_ext_cap(pdev, PCI_EXT_CAP_ID_L1SS); + pl_save_state = pci_find_saved_ext_cap(parent, PCI_EXT_CAP_ID_L1SS); + if (!cl_save_state || !pl_save_state) + return; + + cap = &cl_save_state->cap.data[0]; + cl_ctl2 = *cap++; + cl_ctl1 = *cap; + cap = &pl_save_state->cap.data[0]; + pl_ctl2 = *cap++; + pl_ctl1 = *cap; + + /* + * Disable L1.2 on this downstream endpoint device first, followed + * by the upstream + */ + pci_clear_and_set_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1, + PCI_L1SS_CTL1_L1_2_MASK, 0); + pci_clear_and_set_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, + PCI_L1SS_CTL1_L1_2_MASK, 0); + + /* + * In addition, Common_Mode_Restore_Time and LTR_L1.2_THRESHOLD + * in PCI_L1SS_CTL1 must be programmed *before* setting the L1.2 + * enable bits, even though they're all in PCI_L1SS_CTL1. + */ + pl_l1_2_enable = pl_ctl1 & PCI_L1SS_CTL1_L1_2_MASK; + pl_ctl1 &= ~PCI_L1SS_CTL1_L1_2_MASK; + cl_l1_2_enable = cl_ctl1 & PCI_L1SS_CTL1_L1_2_MASK; + cl_ctl1 &= ~PCI_L1SS_CTL1_L1_2_MASK; + + /* Write back without enables first (above we cleared them in ctl1) */ + pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, pl_ctl2); + pci_write_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL2, cl_ctl2); + pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, pl_ctl1); + pci_write_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1, cl_ctl1); + + /* Then write back the enables */ + if (pl_l1_2_enable || cl_l1_2_enable) { + pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, + pl_ctl1 | pl_l1_2_enable); + pci_write_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1, + cl_ctl1 | cl_l1_2_enable); + } +} + #ifdef CONFIG_PCIEASPM #ifdef MODULE_PARAM_PREFIX @@ -1005,9 +1104,6 @@ void pci_configure_ltr(struct pci_dev *pdev) 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; diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index b809c0b0e0e5..1434bf495db3 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2259,6 +2259,7 @@ static void pci_configure_device(struct pci_dev *dev) pci_configure_extended_tags(dev, NULL); pci_configure_relaxed_ordering(dev); pci_configure_ltr(dev); + pci_configure_aspm_l1ss(dev); pci_configure_eetlp_prefix(dev); pci_configure_serr(dev); -- cgit From c198fafa0125e97728d16411aa653602900ab0bc Mon Sep 17 00:00:00 2001 From: "David E. Box" Date: Fri, 23 Feb 2024 14:58:51 -0600 Subject: PCI/ASPM: Call pci_save_ltr_state() from pci_save_pcie_state() ASPM state is saved and restored from pci_save/restore_pcie_state(). Since the LTR Capability is linked with ASPM, move the LTR save and restore calls there as well. No functional change intended. Suggested-by: Bjorn Helgaas Link: https://lore.kernel.org/r/20240128233212.1139663-6-david.e.box@linux.intel.com Link: https://lore.kernel.org/r/20240223205851.114931-6-helgaas@kernel.org Signed-off-by: David E. Box Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index ca6673588bc0..4ea98665172d 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1624,6 +1624,7 @@ static int pci_save_pcie_state(struct pci_dev *dev) pcie_capability_read_word(dev, PCI_EXP_SLTCTL2, &cap[i++]); pci_save_aspm_l1ss_state(dev); + pci_save_ltr_state(dev); return 0; } @@ -1634,6 +1635,12 @@ static void pci_restore_pcie_state(struct pci_dev *dev) struct pci_cap_saved_state *save_state; u16 *cap, lnkctl; + /* + * Restore max latencies (in the LTR capability) before enabling + * LTR itself in PCI_EXP_DEVCTL2. + */ + pci_restore_ltr_state(dev); + save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP); if (!save_state) return; @@ -1726,7 +1733,6 @@ int pci_save_state(struct pci_dev *dev) if (i != 0) return i; - pci_save_ltr_state(dev); pci_save_dpc_state(dev); pci_save_aer_state(dev); pci_save_ptm_state(dev); @@ -1827,12 +1833,6 @@ void pci_restore_state(struct pci_dev *dev) if (!dev->state_saved) return; - /* - * Restore max latencies (in the LTR capability) before enabling - * LTR itself (in the PCIe capability). - */ - pci_restore_ltr_state(dev); - pci_restore_pcie_state(dev); pci_restore_pasid_state(dev); pci_restore_pri_state(dev); -- cgit From 64dbb2d707444f691539fb12aacf81797786c10b Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 5 Mar 2024 15:15:25 -0600 Subject: PCI/ASPM: Disable L1 before configuring L1 Substates Per PCIe r6.1, sec 5.5.4, L1 must be disabled while setting ASPM L1 PM Substates enable bits. Previously this was enforced by clearing PCI_EXP_LNKCTL_ASPMC before calling pci_restore_aspm_l1ss_state(). Move the L1 (and L0s, although that doesn't seem required) disable into pci_restore_aspm_l1ss_state() itself so it's closer to the code that depends on it. Link: https://lore.kernel.org/r/20240223213733.GA115410@bhelgaas Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 16 +++------------- drivers/pci/pcie/aspm.c | 19 +++++++++++++++++++ 2 files changed, 22 insertions(+), 13 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 4ea98665172d..5a4b501a3f41 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1633,13 +1633,14 @@ static void pci_restore_pcie_state(struct pci_dev *dev) { int i = 0; struct pci_cap_saved_state *save_state; - u16 *cap, lnkctl; + u16 *cap; /* * Restore max latencies (in the LTR capability) before enabling * LTR itself in PCI_EXP_DEVCTL2. */ pci_restore_ltr_state(dev); + pci_restore_aspm_l1ss_state(dev); save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP); if (!save_state) @@ -1654,23 +1655,12 @@ static void pci_restore_pcie_state(struct pci_dev *dev) cap = (u16 *)&save_state->cap.data[0]; pcie_capability_write_word(dev, PCI_EXP_DEVCTL, cap[i++]); - - /* Restore LNKCTL register with ASPM control field clear */ - lnkctl = cap[i++]; - pcie_capability_write_word(dev, PCI_EXP_LNKCTL, - lnkctl & ~PCI_EXP_LNKCTL_ASPMC); - + pcie_capability_write_word(dev, PCI_EXP_LNKCTL, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_SLTCTL, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_RTCTL, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_DEVCTL2, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]); - - pci_restore_aspm_l1ss_state(dev); - - /* Restore ASPM control after restoring L1SS state */ - pcie_capability_set_word(dev, PCI_EXP_LNKCTL, - lnkctl & PCI_EXP_LNKCTL_ASPMC); } static int pci_save_pcix_state(struct pci_dev *dev) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 977eca893b2a..1379b8decdf1 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -105,6 +105,7 @@ void pci_restore_aspm_l1ss_state(struct pci_dev *pdev) struct pci_dev *parent = pdev->bus->self; u32 *cap, pl_ctl1, pl_ctl2, pl_l1_2_enable; u32 cl_ctl1, cl_ctl2, cl_l1_2_enable; + u16 clnkctl, plnkctl; /* * In case BIOS enabled L1.2 when resuming, we need to disable it first @@ -129,6 +130,17 @@ void pci_restore_aspm_l1ss_state(struct pci_dev *pdev) pl_ctl2 = *cap++; pl_ctl1 = *cap; + /* Make sure L0s/L1 are disabled before updating L1SS config */ + pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &clnkctl); + pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &plnkctl); + if (FIELD_GET(PCI_EXP_LNKCTL_ASPMC, clnkctl) || + FIELD_GET(PCI_EXP_LNKCTL_ASPMC, plnkctl)) { + pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, + clnkctl & ~PCI_EXP_LNKCTL_ASPMC); + pcie_capability_write_word(parent, PCI_EXP_LNKCTL, + plnkctl & ~PCI_EXP_LNKCTL_ASPMC); + } + /* * Disable L1.2 on this downstream endpoint device first, followed * by the upstream @@ -161,6 +173,13 @@ void pci_restore_aspm_l1ss_state(struct pci_dev *pdev) pci_write_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1, cl_ctl1 | cl_l1_2_enable); } + + /* Restore L0s/L1 if they were enabled */ + if (FIELD_GET(PCI_EXP_LNKCTL_ASPMC, clnkctl) || + FIELD_GET(PCI_EXP_LNKCTL_ASPMC, plnkctl)) { + pcie_capability_write_word(parent, PCI_EXP_LNKCTL, clnkctl); + pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, plnkctl); + } } #ifdef CONFIG_PCIEASPM -- cgit From 6d4266675279b38c301243f3a4fac4a511b03246 Mon Sep 17 00:00:00 2001 From: Vidya Sagar Date: Fri, 23 Feb 2024 13:36:24 -0600 Subject: PCI/ASPM: Update save_state when configuration changes Many PCIe device drivers save the configuration state of their device during probe and restore it when their .slot_reset() hook is called during PCIe error recovery. If the ASPM configuration is changed after the driver's probe is called and before an error event occurs, .slot_reset() restores the ASPM configuration to what it was at the time of probe, not to what it was just before the occurrence of the error event. This leads to a mismatch in ASPM configuration between the device and its upstream device. Update the saved configuration of the device when the ASPM configuration changes. Link: https://lore.kernel.org/r/20240222174436.3565146-1-vidyas@nvidia.com Signed-off-by: Vidya Sagar [bhelgaas: commit log, rebase to pci/aspm, rename to pci_update_aspm_saved_state() since it updates only LNKCTL, update only ASPMC and CLKREQ_EN in LNKCTL] Signed-off-by: Bjorn Helgaas Reviewed-by: Kuppuswamy Sathyanarayanan Reviewed-by: David E. Box --- drivers/pci/pcie/aspm.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 1379b8decdf1..10160d82c10a 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -301,16 +301,42 @@ static int policy_to_clkpm_state(struct pcie_link_state *link) return 0; } +static void pci_update_aspm_saved_state(struct pci_dev *dev) +{ + struct pci_cap_saved_state *save_state; + u16 *cap, lnkctl, aspm_ctl; + + save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP); + if (!save_state) + return; + + pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &lnkctl); + + /* + * Update ASPM and CLKREQ bits of LNKCTL in save_state. We only + * write PCI_EXP_LNKCTL_CCC during enumeration, so it shouldn't + * change after being captured in save_state. + */ + aspm_ctl = lnkctl & (PCI_EXP_LNKCTL_ASPMC | PCI_EXP_LNKCTL_CLKREQ_EN); + lnkctl &= ~(PCI_EXP_LNKCTL_ASPMC | PCI_EXP_LNKCTL_CLKREQ_EN); + + /* Depends on pci_save_pcie_state(): cap[1] is LNKCTL */ + cap = (u16 *)&save_state->cap.data[0]; + cap[1] = lnkctl | aspm_ctl; +} + static void pcie_set_clkpm_nocheck(struct pcie_link_state *link, int enable) { struct pci_dev *child; struct pci_bus *linkbus = link->pdev->subordinate; u32 val = enable ? PCI_EXP_LNKCTL_CLKREQ_EN : 0; - list_for_each_entry(child, &linkbus->devices, bus_list) + list_for_each_entry(child, &linkbus->devices, bus_list) { pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_CLKREQ_EN, val); + pci_update_aspm_saved_state(child); + } link->clkpm_enabled = !!enable; } @@ -929,6 +955,12 @@ static void pcie_config_aspm_link(struct pcie_link_state *link, u32 state) pcie_config_aspm_dev(parent, upstream); link->aspm_enabled = state; + + /* Update latest ASPM configuration in saved context */ + pci_save_aspm_l1ss_state(link->downstream); + pci_update_aspm_saved_state(link->downstream); + pci_save_aspm_l1ss_state(parent); + pci_update_aspm_saved_state(parent); } static void pcie_config_aspm_path(struct pcie_link_state *link) -- cgit