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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-19 21:00:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-19 21:00:30 +0000 |
commit | e54def4ad8144ab15f826416e2e0f290ef1901b4 (patch) | |
tree | 583f8d4bd95cd67c44ff37b878a7eddfca9ab97a /drivers/pci/pcie/aspm.c | |
parent | Adding upstream version 6.8.12. (diff) | |
download | linux-e54def4ad8144ab15f826416e2e0f290ef1901b4.tar.xz linux-e54def4ad8144ab15f826416e2e0f290ef1901b4.zip |
Adding upstream version 6.9.2.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/pci/pcie/aspm.c')
-rw-r--r-- | drivers/pci/pcie/aspm.c | 268 |
1 files changed, 267 insertions, 1 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index bc0bd86695..47761c7ef2 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -24,6 +24,166 @@ #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); +} + +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; + u16 clnkctl, plnkctl; + + /* + * 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; + + /* 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 + */ + 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); + } + + /* 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, plnkctl); + pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, clnkctl); + } +} + +#ifdef CONFIG_PCIEASPM + #ifdef MODULE_PARAM_PREFIX #undef MODULE_PARAM_PREFIX #endif @@ -141,16 +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; } @@ -769,6 +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) @@ -938,6 +1130,78 @@ 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; + + 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) { @@ -1447,3 +1711,5 @@ bool pcie_aspm_support_enabled(void) { return aspm_support_enabled; } + +#endif /* CONFIG_PCIEASPM */ |