| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright (C) 2005 Linux Networx |
| * (Written by Eric Biederman <ebiederman@lnxi.com> for Linux Networx) |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; version 2 of the License. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #include <console/console.h> |
| #include <delay.h> |
| #include <device/device.h> |
| #include <device/pci.h> |
| #include <device/pci_ids.h> |
| #include <device/pciexp.h> |
| |
| unsigned int pciexp_find_extended_cap(device_t dev, unsigned int cap) |
| { |
| unsigned int this_cap_offset, next_cap_offset; |
| unsigned int this_cap, cafe; |
| |
| this_cap_offset = PCIE_EXT_CAP_OFFSET; |
| do { |
| this_cap = pci_read_config32(dev, this_cap_offset); |
| next_cap_offset = this_cap >> 20; |
| this_cap &= 0xffff; |
| cafe = pci_read_config32(dev, this_cap_offset + 4); |
| cafe &= 0xffff; |
| if (this_cap == cap) |
| return this_cap_offset; |
| else if (cafe == cap) |
| return this_cap_offset + 4; |
| else |
| this_cap_offset = next_cap_offset; |
| } while (next_cap_offset != 0); |
| |
| return 0; |
| } |
| |
| /* |
| * Re-train a PCIe link |
| */ |
| #define PCIE_TRAIN_RETRY 10000 |
| static int pciexp_retrain_link(device_t dev, unsigned cap) |
| { |
| unsigned try = PCIE_TRAIN_RETRY; |
| u16 lnk; |
| |
| /* Start link retraining */ |
| lnk = pci_read_config16(dev, cap + PCI_EXP_LNKCTL); |
| lnk |= PCI_EXP_LNKCTL_RL; |
| pci_write_config16(dev, cap + PCI_EXP_LNKCTL, lnk); |
| |
| /* Wait for training to complete */ |
| while (try--) { |
| lnk = pci_read_config16(dev, cap + PCI_EXP_LNKSTA); |
| if (!(lnk & PCI_EXP_LNKSTA_LT)) |
| return 0; |
| udelay(100); |
| } |
| |
| printk(BIOS_ERR, "%s: Link Retrain timeout\n", dev_path(dev)); |
| return -1; |
| } |
| |
| /* |
| * Check the Slot Clock Configuration for root port and endpoint |
| * and enable Common Clock Configuration if possible. If CCC is |
| * enabled the link must be retrained. |
| */ |
| static void pciexp_enable_common_clock(device_t root, unsigned root_cap, |
| device_t endp, unsigned endp_cap) |
| { |
| u16 root_scc, endp_scc, lnkctl; |
| |
| /* Get Slot Clock Configuration for root port */ |
| root_scc = pci_read_config16(root, root_cap + PCI_EXP_LNKSTA); |
| root_scc &= PCI_EXP_LNKSTA_SLC; |
| |
| /* Get Slot Clock Configuration for endpoint */ |
| endp_scc = pci_read_config16(endp, endp_cap + PCI_EXP_LNKSTA); |
| endp_scc &= PCI_EXP_LNKSTA_SLC; |
| |
| /* Enable Common Clock Configuration and retrain */ |
| if (root_scc && endp_scc) { |
| printk(BIOS_INFO, "Enabling Common Clock Configuration\n"); |
| |
| /* Set in endpoint */ |
| lnkctl = pci_read_config16(endp, endp_cap + PCI_EXP_LNKCTL); |
| lnkctl |= PCI_EXP_LNKCTL_CCC; |
| pci_write_config16(endp, endp_cap + PCI_EXP_LNKCTL, lnkctl); |
| |
| /* Set in root port */ |
| lnkctl = pci_read_config16(root, root_cap + PCI_EXP_LNKCTL); |
| lnkctl |= PCI_EXP_LNKCTL_CCC; |
| pci_write_config16(root, root_cap + PCI_EXP_LNKCTL, lnkctl); |
| |
| /* Retrain link if CCC was enabled */ |
| pciexp_retrain_link(root, root_cap); |
| } |
| } |
| |
| static void pciexp_enable_clock_power_pm(device_t endp, unsigned endp_cap) |
| { |
| /* check if per port clk req is supported in device */ |
| u32 endp_ca; |
| u16 lnkctl; |
| endp_ca = pci_read_config32(endp, endp_cap + PCI_EXP_LNKCAP); |
| if ((endp_ca & PCI_EXP_CLK_PM) == 0) { |
| printk(BIOS_INFO, "PCIE CLK PM is not supported by endpoint"); |
| return; |
| } |
| lnkctl = pci_read_config16(endp, endp_cap + PCI_EXP_LNKCTL); |
| lnkctl = lnkctl | PCI_EXP_EN_CLK_PM; |
| pci_write_config16(endp, endp_cap + PCI_EXP_LNKCTL, lnkctl); |
| } |
| |
| static void pcie_update_cfg(device_t dev, int reg, u32 mask, u32 or) |
| { |
| u32 reg32; |
| |
| reg32 = pci_read_config32(dev, reg); |
| reg32 &= mask; |
| reg32 |= or; |
| pci_write_config32(dev, reg, reg32); |
| } |
| |
| static void pciexp_config_max_latency(device_t root, device_t dev) |
| { |
| unsigned int cap; |
| cap = pciexp_find_extended_cap(dev, PCIE_EXT_CAP_LTR_ID); |
| if ((cap) && (root->ops->ops_pci != NULL) && |
| (root->ops->ops_pci->set_L1_ss_latency != NULL)) |
| root->ops->ops_pci->set_L1_ss_latency(dev, cap + 4); |
| } |
| |
| static void pciexp_enable_ltr(device_t dev) |
| { |
| unsigned int cap; |
| cap = pci_find_capability(dev, PCI_CAP_ID_PCIE); |
| if(!cap) { |
| printk(BIOS_INFO, "Failed to enable LTR for dev = %s\n", |
| dev_path(dev)); |
| return; |
| } |
| pcie_update_cfg(dev, cap + 0x28, ~(1 << 10), 1 << 10); |
| } |
| |
| static unsigned char pciexp_L1_substate_cal(device_t dev, unsigned int endp_cap, |
| unsigned int *data) |
| { |
| unsigned char mult[4] = {2, 10, 100, 0}; |
| |
| unsigned int L1SubStateSupport = *data & 0xf; |
| unsigned int comm_mode_rst_time = (*data >> 8) & 0xff; |
| unsigned int power_on_scale = (*data >> 16) & 0x3; |
| unsigned int power_on_value = (*data >> 19) & 0x1f; |
| |
| unsigned int endp_data = pci_read_config32(dev, endp_cap + 4); |
| unsigned int endp_L1SubStateSupport = endp_data & 0xf; |
| unsigned int endp_comm_mode_restore_time = (endp_data >> 8) & 0xff; |
| unsigned int endp_power_on_scale = (endp_data >> 16) & 0x3; |
| unsigned int endp_power_on_value = (endp_data >> 19) & 0x1f; |
| |
| L1SubStateSupport &= endp_L1SubStateSupport; |
| |
| if (L1SubStateSupport == 0) |
| return 0; |
| |
| if (power_on_value * mult[power_on_scale] < |
| endp_power_on_value * mult[endp_power_on_scale]) { |
| power_on_value = endp_power_on_value; |
| power_on_scale = endp_power_on_scale; |
| } |
| if (comm_mode_rst_time < endp_comm_mode_restore_time) |
| comm_mode_rst_time = endp_comm_mode_restore_time; |
| |
| *data = (comm_mode_rst_time << 8) | (power_on_scale << 16) |
| | (power_on_value << 19) | L1SubStateSupport; |
| |
| return 1; |
| } |
| |
| static void pciexp_L1_substate_commit(device_t root, device_t dev, |
| unsigned int root_cap, unsigned int end_cap) |
| { |
| device_t dev_t; |
| unsigned char L1_ss_ok; |
| unsigned int rp_L1_support = pci_read_config32(root, root_cap + 4); |
| unsigned int L1SubStateSupport; |
| unsigned int comm_mode_rst_time; |
| unsigned int power_on_scale; |
| unsigned int endp_power_on_value; |
| |
| for (dev_t = dev; dev_t; dev_t = dev_t->sibling) { |
| /* |
| * rp_L1_support is init'd above from root port. |
| * it needs coordination with endpoints to reach in common. |
| * if certain endpoint doesn't support L1 Sub-State, abort |
| * this feature enabling. |
| */ |
| L1_ss_ok = pciexp_L1_substate_cal(dev_t, end_cap, |
| &rp_L1_support); |
| if (!L1_ss_ok) |
| return; |
| } |
| |
| L1SubStateSupport = rp_L1_support & 0xf; |
| comm_mode_rst_time = (rp_L1_support >> 8) & 0xff; |
| power_on_scale = (rp_L1_support >> 16) & 0x3; |
| endp_power_on_value = (rp_L1_support >> 19) & 0x1f; |
| |
| printk(BIOS_INFO, "L1 Sub-State supported from root port %d\n", |
| root->path.pci.devfn >> 3); |
| printk(BIOS_INFO, "L1 Sub-State Support = 0x%x\n", L1SubStateSupport); |
| printk(BIOS_INFO, "CommonModeRestoreTime = 0x%x\n", comm_mode_rst_time); |
| printk(BIOS_INFO, "Power On Value = 0x%x, Power On Scale = 0x%x\n", |
| endp_power_on_value, power_on_scale); |
| |
| pciexp_enable_ltr(root); |
| |
| pcie_update_cfg(root, root_cap + 0x08, ~0xff00, |
| (comm_mode_rst_time << 8)); |
| |
| pcie_update_cfg(root, root_cap + 0x0c , 0xffffff04, |
| (endp_power_on_value << 3) | (power_on_scale)); |
| |
| pcie_update_cfg(root, root_cap + 0x08, ~0xe3ff0000, |
| (1 << 21) | (1 << 23) | (1 << 30)); |
| |
| pcie_update_cfg(root, root_cap + 0x08, ~0x1f, |
| L1SubStateSupport); |
| |
| for (dev_t = dev; dev_t; dev_t = dev_t->sibling) { |
| pcie_update_cfg(dev_t, end_cap + 0x0c , 0xffffff04, |
| (endp_power_on_value << 3) | (power_on_scale)); |
| |
| pcie_update_cfg(dev_t, end_cap + 0x08, ~0xe3ff0000, |
| (1 << 21) | (1 << 23) | (1 << 30)); |
| |
| pcie_update_cfg(dev_t, end_cap + 0x08, ~0x1f, |
| L1SubStateSupport); |
| |
| pciexp_enable_ltr(dev_t); |
| |
| pciexp_config_max_latency(root, dev_t); |
| } |
| } |
| |
| static void pciexp_config_L1_sub_state(device_t root, device_t dev) |
| { |
| unsigned int root_cap, end_cap; |
| |
| /* Do it for function 0 only */ |
| if (dev->path.pci.devfn & 0x7) |
| return; |
| |
| root_cap = pciexp_find_extended_cap(root, PCIE_EXT_CAP_L1SS_ID); |
| if (!root_cap) |
| return; |
| |
| end_cap = pciexp_find_extended_cap(dev, PCIE_EXT_CAP_L1SS_ID); |
| if (!end_cap) { |
| end_cap = pciexp_find_extended_cap(dev, 0xcafe); |
| if (!end_cap) |
| return; |
| } |
| |
| pciexp_L1_substate_commit(root, dev, root_cap, end_cap); |
| } |
| |
| /* |
| * Determine the ASPM L0s or L1 exit latency for a link |
| * by checking both root port and endpoint and returning |
| * the highest latency value. |
| */ |
| static int pciexp_aspm_latency(device_t root, unsigned root_cap, |
| device_t endp, unsigned endp_cap, |
| enum aspm_type type) |
| { |
| int root_lat = 0, endp_lat = 0; |
| u32 root_lnkcap, endp_lnkcap; |
| |
| root_lnkcap = pci_read_config32(root, root_cap + PCI_EXP_LNKCAP); |
| endp_lnkcap = pci_read_config32(endp, endp_cap + PCI_EXP_LNKCAP); |
| |
| /* Make sure the link supports this ASPM type by checking |
| * capability bits 11:10 with aspm_type offset by 1 */ |
| if (!(root_lnkcap & (1 << (type + 9))) || |
| !(endp_lnkcap & (1 << (type + 9)))) |
| return -1; |
| |
| /* Find the one with higher latency */ |
| switch (type) { |
| case PCIE_ASPM_L0S: |
| root_lat = (root_lnkcap & PCI_EXP_LNKCAP_L0SEL) >> 12; |
| endp_lat = (endp_lnkcap & PCI_EXP_LNKCAP_L0SEL) >> 12; |
| break; |
| case PCIE_ASPM_L1: |
| root_lat = (root_lnkcap & PCI_EXP_LNKCAP_L1EL) >> 15; |
| endp_lat = (endp_lnkcap & PCI_EXP_LNKCAP_L1EL) >> 15; |
| break; |
| default: |
| return -1; |
| } |
| |
| return (endp_lat > root_lat) ? endp_lat : root_lat; |
| } |
| |
| /* |
| * Enable ASPM on PCIe root port and endpoint. |
| */ |
| static void pciexp_enable_aspm(device_t root, unsigned root_cap, |
| device_t endp, unsigned endp_cap) |
| { |
| const char *aspm_type_str[] = { "None", "L0s", "L1", "L0s and L1" }; |
| enum aspm_type apmc = PCIE_ASPM_NONE; |
| int exit_latency, ok_latency; |
| u16 lnkctl; |
| u32 devcap; |
| |
| /* Get endpoint device capabilities for acceptable limits */ |
| devcap = pci_read_config32(endp, endp_cap + PCI_EXP_DEVCAP); |
| |
| /* Enable L0s if it is within endpoint acceptable limit */ |
| ok_latency = (devcap & PCI_EXP_DEVCAP_L0S) >> 6; |
| exit_latency = pciexp_aspm_latency(root, root_cap, endp, endp_cap, |
| PCIE_ASPM_L0S); |
| if (exit_latency >= 0 && exit_latency <= ok_latency) |
| apmc |= PCIE_ASPM_L0S; |
| |
| /* Enable L1 if it is within endpoint acceptable limit */ |
| ok_latency = (devcap & PCI_EXP_DEVCAP_L1) >> 9; |
| exit_latency = pciexp_aspm_latency(root, root_cap, endp, endp_cap, |
| PCIE_ASPM_L1); |
| if (exit_latency >= 0 && exit_latency <= ok_latency) |
| apmc |= PCIE_ASPM_L1; |
| |
| if (apmc != PCIE_ASPM_NONE) { |
| /* Set APMC in root port first */ |
| lnkctl = pci_read_config16(root, root_cap + PCI_EXP_LNKCTL); |
| lnkctl |= apmc; |
| pci_write_config16(root, root_cap + PCI_EXP_LNKCTL, lnkctl); |
| |
| /* Set APMC in endpoint device next */ |
| lnkctl = pci_read_config16(endp, endp_cap + PCI_EXP_LNKCTL); |
| lnkctl |= apmc; |
| pci_write_config16(endp, endp_cap + PCI_EXP_LNKCTL, lnkctl); |
| |
| /* Enable ASPM role based error reporting. */ |
| devcap = pci_read_config32(endp, endp_cap + PCI_EXP_DEVCAP); |
| devcap |= PCI_EXP_DEVCAP_RBER; |
| pci_write_config32(endp, endp_cap + PCI_EXP_DEVCAP, devcap); |
| } |
| |
| printk(BIOS_INFO, "ASPM: Enabled %s\n", aspm_type_str[apmc]); |
| } |
| |
| static void pciexp_tune_dev(device_t dev) |
| { |
| device_t root = dev->bus->dev; |
| unsigned int root_cap, cap; |
| |
| cap = pci_find_capability(dev, PCI_CAP_ID_PCIE); |
| if (!cap) |
| return; |
| |
| root_cap = pci_find_capability(root, PCI_CAP_ID_PCIE); |
| if (!root_cap) |
| return; |
| |
| /* Check for and enable Common Clock */ |
| if (IS_ENABLED(CONFIG_PCIEXP_COMMON_CLOCK)) |
| pciexp_enable_common_clock(root, root_cap, dev, cap); |
| |
| /* Check if per port CLK req is supported by endpoint*/ |
| if (IS_ENABLED(CONFIG_PCIEXP_CLK_PM)) |
| pciexp_enable_clock_power_pm(dev, cap); |
| |
| /* Enable L1 Sub-State when both root port and endpoint support */ |
| if (IS_ENABLED(CONFIG_PCIEXP_L1_SUB_STATE)) |
| pciexp_config_L1_sub_state(root, dev); |
| |
| /* Check for and enable ASPM */ |
| if (IS_ENABLED(CONFIG_PCIEXP_ASPM)) |
| pciexp_enable_aspm(root, root_cap, dev, cap); |
| } |
| |
| void pciexp_scan_bus(struct bus *bus, unsigned int min_devfn, |
| unsigned int max_devfn) |
| { |
| device_t child; |
| |
| pci_scan_bus(bus, min_devfn, max_devfn); |
| |
| for (child = bus->children; child; child = child->sibling) { |
| if ((child->path.pci.devfn < min_devfn) || |
| (child->path.pci.devfn > max_devfn)) { |
| continue; |
| } |
| pciexp_tune_dev(child); |
| } |
| } |
| |
| void pciexp_scan_bridge(device_t dev) |
| { |
| do_pci_scan_bridge(dev, pciexp_scan_bus); |
| } |
| |
| /** Default device operations for PCI Express bridges */ |
| static struct pci_operations pciexp_bus_ops_pci = { |
| .set_subsystem = 0, |
| }; |
| |
| struct device_operations default_pciexp_ops_bus = { |
| .read_resources = pci_bus_read_resources, |
| .set_resources = pci_dev_set_resources, |
| .enable_resources = pci_bus_enable_resources, |
| .init = 0, |
| .scan_bus = pciexp_scan_bridge, |
| .enable = 0, |
| .reset_bus = pci_bus_reset, |
| .ops_pci = &pciexp_bus_ops_pci, |
| }; |