From df8f10587d3d11b055d54138994a1a9a681da0c4 Mon Sep 17 00:00:00 2001 From: "Saheed O. Bolarinwa" Date: Thu, 15 Oct 2020 14:30:39 -0500 Subject: [PATCH] PCI/ASPM: Remove struct pcie_link_state.l1ss Previously we computed L1.2 parameters in the enumeration path, saved them in struct pcie_link_state.l1ss, and programmed them into the devices whenever we enabled or disabled L1.2 on the link. But these parameters are constant and don't need to be updated when enabling/disabling L1.2. Compute and program the L1.2 parameters once during enumeration and remove the struct pcie_link_state.l1ss member. No functional change intended. [bhelgaas: rework to program L1.2 parameters during enumeration] Link: https://lore.kernel.org/r/20201015193039.12585-13-helgaas@kernel.org Signed-off-by: Saheed O. Bolarinwa Signed-off-by: Bjorn Helgaas --- drivers/pci/pcie/aspm.c | 84 +++++++++++++++++++++++++------------------ include/uapi/linux/pci_regs.h | 1 + 2 files changed, 50 insertions(+), 35 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index d76f239..ac0557a 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -74,12 +74,6 @@ struct pcie_link_state { * has one slot under it, so at most there are 8 functions. */ struct aspm_latency acceptable[8]; - - /* L1 PM Substate info */ - struct { - u32 ctl1; /* value to be programmed in ctl1 */ - u32 ctl2; /* value to be programmed in ctl2 */ - } l1ss; }; static int aspm_disabled, aspm_force; @@ -461,8 +455,9 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link, struct pci_dev *child = link->downstream, *parent = link->pdev; u32 val1, val2, scale1, scale2; u32 t_common_mode, t_power_on, l1_2_threshold, scale, value; - - link->l1ss.ctl1 = link->l1ss.ctl2 = 0; + 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; @@ -480,10 +475,10 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link, if (calc_l1ss_pwron(parent, scale1, val1) > calc_l1ss_pwron(child, scale2, val2)) { - link->l1ss.ctl2 |= scale1 | (val1 << 3); + ctl2 |= scale1 | (val1 << 3); t_power_on = calc_l1ss_pwron(parent, scale1, val1); } else { - link->l1ss.ctl2 |= scale2 | (val2 << 3); + ctl2 |= scale2 | (val2 << 3); t_power_on = calc_l1ss_pwron(child, scale2, val2); } @@ -499,7 +494,50 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link, */ l1_2_threshold = 2 + 4 + t_common_mode + t_power_on; encode_l12_threshold(l1_2_threshold, &scale, &value); - link->l1ss.ctl1 |= t_common_mode << 8 | scale << 29 | value << 16; + ctl1 |= t_common_mode << 8 | scale << 29 | value << 16; + + pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, &pctl1); + pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, &pctl2); + pci_read_config_dword(child, child->l1ss + PCI_L1SS_CTL1, &cctl1); + pci_read_config_dword(child, child->l1ss + PCI_L1SS_CTL2, &cctl2); + + if (ctl1 == pctl1 && ctl1 == cctl1 && + 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); + } } static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) @@ -679,30 +717,6 @@ static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state) PCI_EXP_LNKCTL_ASPM_L1, 0); } - if (enable_req & ASPM_STATE_L1_2_MASK) { - - /* Program T_POWER_ON times in both ports */ - pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, - link->l1ss.ctl2); - pci_write_config_dword(child, child->l1ss + PCI_L1SS_CTL2, - link->l1ss.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, - link->l1ss.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, - link->l1ss.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, - link->l1ss.ctl1); - } - val = 0; if (state & ASPM_STATE_L1_1) val |= PCI_L1SS_CTL1_ASPM_L1_1; diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index 06846ec..c7e0acb 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -1058,6 +1058,7 @@ #define PCI_L1SS_CTL1_PCIPM_L1_1 0x00000002 /* PCI-PM L1.1 Enable */ #define PCI_L1SS_CTL1_ASPM_L1_2 0x00000004 /* ASPM L1.2 Enable */ #define PCI_L1SS_CTL1_ASPM_L1_1 0x00000008 /* ASPM L1.1 Enable */ +#define PCI_L1SS_CTL1_L1_2_MASK 0x00000005 #define PCI_L1SS_CTL1_L1SS_MASK 0x0000000f #define PCI_L1SS_CTL1_CM_RESTORE_TIME 0x0000ff00 /* Common_Mode_Restore_Time */ #define PCI_L1SS_CTL1_LTR_L12_TH_VALUE 0x03ff0000 /* LTR_L1.2_THRESHOLD_Value */ -- 2.7.4