diff options
Diffstat (limited to 'drivers/pci/pcie/rcec.c')
| -rw-r--r-- | drivers/pci/pcie/rcec.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/drivers/pci/pcie/rcec.c b/drivers/pci/pcie/rcec.c new file mode 100644 index 000000000..d0bcd141a --- /dev/null +++ b/drivers/pci/pcie/rcec.c @@ -0,0 +1,190 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Root Complex Event Collector Support + * + * Authors: + * Sean V Kelley <sean.v.kelley@intel.com> + * Qiuxu Zhuo <qiuxu.zhuo@intel.com> + * + * Copyright (C) 2020 Intel Corp. + */ + +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/pci_regs.h> + +#include "../pci.h" + +struct walk_rcec_data { + struct pci_dev *rcec; + int (*user_callback)(struct pci_dev *dev, void *data); + void *user_data; +}; + +static bool rcec_assoc_rciep(struct pci_dev *rcec, struct pci_dev *rciep) +{ + unsigned long bitmap = rcec->rcec_ea->bitmap; + unsigned int devn; + + /* An RCiEP found on a different bus in range */ + if (rcec->bus->number != rciep->bus->number) + return true; + + /* Same bus, so check bitmap */ + for_each_set_bit(devn, &bitmap, 32) + if (devn == PCI_SLOT(rciep->devfn)) + return true; + + return false; +} + +static int link_rcec_helper(struct pci_dev *dev, void *data) +{ + struct walk_rcec_data *rcec_data = data; + struct pci_dev *rcec = rcec_data->rcec; + + if ((pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) && + rcec_assoc_rciep(rcec, dev)) { + dev->rcec = rcec; + pci_dbg(dev, "PME & error events signaled via %s\n", + pci_name(rcec)); + } + + return 0; +} + +static int walk_rcec_helper(struct pci_dev *dev, void *data) +{ + struct walk_rcec_data *rcec_data = data; + struct pci_dev *rcec = rcec_data->rcec; + + if ((pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) && + rcec_assoc_rciep(rcec, dev)) + rcec_data->user_callback(dev, rcec_data->user_data); + + return 0; +} + +static void walk_rcec(int (*cb)(struct pci_dev *dev, void *data), + void *userdata) +{ + struct walk_rcec_data *rcec_data = userdata; + struct pci_dev *rcec = rcec_data->rcec; + u8 nextbusn, lastbusn; + struct pci_bus *bus; + unsigned int bnr; + + if (!rcec->rcec_ea) + return; + + /* Walk own bus for bitmap based association */ + pci_walk_bus(rcec->bus, cb, rcec_data); + + nextbusn = rcec->rcec_ea->nextbusn; + lastbusn = rcec->rcec_ea->lastbusn; + + /* All RCiEP devices are on the same bus as the RCEC */ + if (nextbusn == 0xff && lastbusn == 0x00) + return; + + for (bnr = nextbusn; bnr <= lastbusn; bnr++) { + /* No association indicated (PCIe 5.0-1, 7.9.10.3) */ + if (bnr == rcec->bus->number) + continue; + + bus = pci_find_bus(pci_domain_nr(rcec->bus), bnr); + if (!bus) + continue; + + /* Find RCiEP devices on the given bus ranges */ + pci_walk_bus(bus, cb, rcec_data); + } +} + +/** + * pcie_link_rcec - Link RCiEP devices associated with RCEC. + * @rcec: RCEC whose RCiEP devices should be linked. + * + * Link the given RCEC to each RCiEP device found. + */ +void pcie_link_rcec(struct pci_dev *rcec) +{ + struct walk_rcec_data rcec_data; + + if (!rcec->rcec_ea) + return; + + rcec_data.rcec = rcec; + rcec_data.user_callback = NULL; + rcec_data.user_data = NULL; + + walk_rcec(link_rcec_helper, &rcec_data); +} + +/** + * pcie_walk_rcec - Walk RCiEP devices associating with RCEC and call callback. + * @rcec: RCEC whose RCiEP devices should be walked + * @cb: Callback to be called for each RCiEP device found + * @userdata: Arbitrary pointer to be passed to callback + * + * Walk the given RCEC. Call the callback on each RCiEP found. + * + * If @cb returns anything other than 0, break out. + */ +void pcie_walk_rcec(struct pci_dev *rcec, int (*cb)(struct pci_dev *, void *), + void *userdata) +{ + struct walk_rcec_data rcec_data; + + if (!rcec->rcec_ea) + return; + + rcec_data.rcec = rcec; + rcec_data.user_callback = cb; + rcec_data.user_data = userdata; + + walk_rcec(walk_rcec_helper, &rcec_data); +} + +void pci_rcec_init(struct pci_dev *dev) +{ + struct rcec_ea *rcec_ea; + u32 rcec, hdr, busn; + u8 ver; + + /* Only for Root Complex Event Collectors */ + if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_EC) + return; + + rcec = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_RCEC); + if (!rcec) + return; + + rcec_ea = kzalloc(sizeof(*rcec_ea), GFP_KERNEL); + if (!rcec_ea) + return; + + pci_read_config_dword(dev, rcec + PCI_RCEC_RCIEP_BITMAP, + &rcec_ea->bitmap); + + /* Check whether RCEC BUSN register is present */ + pci_read_config_dword(dev, rcec, &hdr); + ver = PCI_EXT_CAP_VER(hdr); + if (ver >= PCI_RCEC_BUSN_REG_VER) { + pci_read_config_dword(dev, rcec + PCI_RCEC_BUSN, &busn); + rcec_ea->nextbusn = PCI_RCEC_BUSN_NEXT(busn); + rcec_ea->lastbusn = PCI_RCEC_BUSN_LAST(busn); + } else { + /* Avoid later ver check by setting nextbusn */ + rcec_ea->nextbusn = 0xff; + rcec_ea->lastbusn = 0x00; + } + + dev->rcec_ea = rcec_ea; +} + +void pci_rcec_exit(struct pci_dev *dev) +{ + kfree(dev->rcec_ea); + dev->rcec_ea = NULL; +} |