diff options
| author | Vidya Sagar <vidyas@nvidia.com> | 2022-09-13 16:18:21 +0300 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2022-10-05 04:32:39 +0300 |
| commit | 5e85eba6f50dc288c22083a7e213152bcc4b8208 (patch) | |
| tree | 0d7b2cc23f3bf171dfd5c8fef55404ea995533b0 /drivers/pci/pcie/aspm.c | |
| parent | 568035b01cfb107af8d2e4bd2fb9aea22cf5b868 (diff) | |
| download | linux-5e85eba6f50dc288c22083a7e213152bcc4b8208.tar.xz | |
PCI/ASPM: Refactor L1 PM Substates Control Register programming
Refactor the code to extract the common code to program Control
Registers 1 and 2 of the L1 PM Substates capability to a new function
aspm_program_l1ss() and call it for both parent and child devices.
[bhelgaas: squash in update to preserve fields we're not updating from
https://lore.kernel.org/r/36fa13c5-e0f8-022f-77f7-7908e4df98b8@nvidia.com]
Link: https://lore.kernel.org/r/20220913131822.16557-2-vidyas@nvidia.com
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/pcie/aspm.c')
| -rw-r--r-- | drivers/pci/pcie/aspm.c | 74 |
1 files changed, 40 insertions, 34 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index a8aec190986c..b4bdadc4ac35 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -455,6 +455,31 @@ static void pci_clear_and_set_dword(struct pci_dev *pdev, int pos, pci_write_config_dword(pdev, pos, val); } +static void aspm_program_l1ss(struct pci_dev *dev, u32 ctl1, u32 ctl2) +{ + u16 l1ss = dev->l1ss; + u32 l1_2_enable; + + /* + * Per PCIe r6.0, sec 5.5.4, T_POWER_ON in PCI_L1SS_CTL2 must be + * programmed prior to setting the L1.2 enable bits in PCI_L1SS_CTL1. + */ + pci_write_config_dword(dev, l1ss + PCI_L1SS_CTL2, ctl2); + + /* + * 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. + */ + l1_2_enable = ctl1 & PCI_L1SS_CTL1_L1_2_MASK; + ctl1 &= ~PCI_L1SS_CTL1_L1_2_MASK; + + pci_write_config_dword(dev, l1ss + PCI_L1SS_CTL1, ctl1); + if (l1_2_enable) + pci_write_config_dword(dev, l1ss + PCI_L1SS_CTL1, + ctl1 | l1_2_enable); +} + /* Calculate L1.2 PM substate timing parameters */ static void aspm_calc_l1ss_info(struct pcie_link_state *link, u32 parent_l1ss_cap, u32 child_l1ss_cap) @@ -464,7 +489,6 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link, u32 t_common_mode, t_power_on, l1_2_threshold, scale, value; u32 ctl1 = 0, ctl2 = 0; u32 pctl1, pctl2, cctl1, cctl2; - u32 pl1_2_enables, cl1_2_enables; if (!(link->aspm_support & ASPM_STATE_L1_2_MASK)) return; @@ -513,39 +537,21 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link, ctl2 == pctl2 && ctl2 == cctl2) return; - /* Disable L1.2 while updating. See PCIe r5.0, sec 5.5.4, 7.8.3.3 */ - pl1_2_enables = pctl1 & PCI_L1SS_CTL1_L1_2_MASK; - cl1_2_enables = cctl1 & PCI_L1SS_CTL1_L1_2_MASK; - - if (pl1_2_enables || cl1_2_enables) { - pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1, - PCI_L1SS_CTL1_L1_2_MASK, 0); - pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1, - PCI_L1SS_CTL1_L1_2_MASK, 0); - } - - /* Program T_POWER_ON times in both ports */ - pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, ctl2); - pci_write_config_dword(child, child->l1ss + PCI_L1SS_CTL2, ctl2); - - /* Program Common_Mode_Restore_Time in upstream device */ - pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1, - PCI_L1SS_CTL1_CM_RESTORE_TIME, ctl1); - - /* Program LTR_L1.2_THRESHOLD time in both ports */ - pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1, - PCI_L1SS_CTL1_LTR_L12_TH_VALUE | - PCI_L1SS_CTL1_LTR_L12_TH_SCALE, ctl1); - pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1, - PCI_L1SS_CTL1_LTR_L12_TH_VALUE | - PCI_L1SS_CTL1_LTR_L12_TH_SCALE, ctl1); - - if (pl1_2_enables || cl1_2_enables) { - pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1, 0, - pl1_2_enables); - pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1, 0, - cl1_2_enables); - } + pctl1 &= ~(PCI_L1SS_CTL1_CM_RESTORE_TIME | + PCI_L1SS_CTL1_LTR_L12_TH_VALUE | + PCI_L1SS_CTL1_LTR_L12_TH_SCALE); + pctl1 |= (ctl1 & (PCI_L1SS_CTL1_CM_RESTORE_TIME | + PCI_L1SS_CTL1_LTR_L12_TH_VALUE | + PCI_L1SS_CTL1_LTR_L12_TH_SCALE)); + aspm_program_l1ss(parent, pctl1, ctl2); + + cctl1 &= ~(PCI_L1SS_CTL1_CM_RESTORE_TIME | + PCI_L1SS_CTL1_LTR_L12_TH_VALUE | + PCI_L1SS_CTL1_LTR_L12_TH_SCALE); + cctl1 |= (ctl1 & (PCI_L1SS_CTL1_CM_RESTORE_TIME | + PCI_L1SS_CTL1_LTR_L12_TH_VALUE | + PCI_L1SS_CTL1_LTR_L12_TH_SCALE)); + aspm_program_l1ss(child, cctl1, ctl2); } static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) |