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author | Stefan Reinauer <reinauer@chromium.org> | 2012-11-30 12:34:04 -0800 |
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committer | Ronald G. Minnich <rminnich@gmail.com> | 2012-11-30 23:59:58 +0100 |
commit | 8d7115560d469f901d7d8ccb242d0b437e7394aa (patch) | |
tree | 0f1b4bd63c48a233c49d5a9ca15f08a1675d1ff4 /src/device/pciexp_device.c | |
parent | 4b6be985aae8bff84ae442e7be7669e93694fa1e (diff) | |
download | coreboot-8d7115560d469f901d7d8ccb242d0b437e7394aa.tar.xz |
Rename devices -> device
to match src/include/device
Change-Id: I5d0e5b4361c34881a3b81347aac48738cb5b9af0
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/1960
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Diffstat (limited to 'src/device/pciexp_device.c')
-rw-r--r-- | src/device/pciexp_device.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/src/device/pciexp_device.c b/src/device/pciexp_device.c new file mode 100644 index 0000000000..36f3e6a455 --- /dev/null +++ b/src/device/pciexp_device.c @@ -0,0 +1,252 @@ +/* + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <console/console.h> +#include <delay.h> +#include <device/device.h> +#include <device/pci.h> +#include <device/pci_ids.h> +#include <device/pciexp.h> + +#if CONFIG_PCIEXP_COMMON_CLOCK +/* + * 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); + } +} +#endif /* CONFIG_PCIEXP_COMMON_CLOCK */ + +#if CONFIG_PCIEXP_ASPM +/* + * 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. + * + * Returns APMC value: + * -1 = Error + * 0 = no ASPM + * 1 = L0s Enabled + * 2 = L1 Enabled + * 3 = L0s and L1 Enabled + */ +static enum aspm_type 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); + } + + printk(BIOS_INFO, "ASPM: Enabled %s\n", aspm_type_str[apmc]); + return apmc; +} +#endif /* CONFIG_PCIEXP_ASPM */ + +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; + +#if CONFIG_PCIEXP_COMMON_CLOCK + /* Check for and enable Common Clock */ + pciexp_enable_common_clock(root, root_cap, dev, cap); +#endif + +#if CONFIG_PCIEXP_ASPM + /* Check for and enable ASPM */ + enum aspm_type apmc = pciexp_enable_aspm(root, root_cap, dev, cap); + + if (apmc != PCIE_ASPM_NONE) { + /* Enable ASPM role based error reporting. */ + u32 reg32 = pci_read_config32(dev, cap + PCI_EXP_DEVCAP); + reg32 |= PCI_EXP_DEVCAP_RBER; + pci_write_config32(dev, cap + PCI_EXP_DEVCAP, reg32); + } +#endif +} + +unsigned int pciexp_scan_bus(struct bus *bus, unsigned int min_devfn, + unsigned int max_devfn, unsigned int max) +{ + device_t child; + + max = pci_scan_bus(bus, min_devfn, max_devfn, max); + + 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); + } + return max; +} + +unsigned int pciexp_scan_bridge(device_t dev, unsigned int max) +{ + return do_pci_scan_bridge(dev, max, 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, +}; |