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1// SPDX-License-Identifier: GPL-2.02/*3 * Root Complex Event Collector Support4 *5 * Authors:6 * Sean V Kelley <sean.v.kelley@intel.com>7 * Qiuxu Zhuo <qiuxu.zhuo@intel.com>8 *9 * Copyright (C) 2020 Intel Corp.10 */11 12#include <linux/kernel.h>13#include <linux/pci.h>14#include <linux/pci_regs.h>15 16#include "../pci.h"17 18struct walk_rcec_data {19 struct pci_dev *rcec;20 int (*user_callback)(struct pci_dev *dev, void *data);21 void *user_data;22};23 24static bool rcec_assoc_rciep(struct pci_dev *rcec, struct pci_dev *rciep)25{26 unsigned long bitmap = rcec->rcec_ea->bitmap;27 unsigned int devn;28 29 /* An RCiEP found on a different bus in range */30 if (rcec->bus->number != rciep->bus->number)31 return true;32 33 /* Same bus, so check bitmap */34 for_each_set_bit(devn, &bitmap, 32)35 if (devn == PCI_SLOT(rciep->devfn))36 return true;37 38 return false;39}40 41static int link_rcec_helper(struct pci_dev *dev, void *data)42{43 struct walk_rcec_data *rcec_data = data;44 struct pci_dev *rcec = rcec_data->rcec;45 46 if ((pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) &&47 rcec_assoc_rciep(rcec, dev)) {48 dev->rcec = rcec;49 pci_dbg(dev, "PME & error events signaled via %s\n",50 pci_name(rcec));51 }52 53 return 0;54}55 56static int walk_rcec_helper(struct pci_dev *dev, void *data)57{58 struct walk_rcec_data *rcec_data = data;59 struct pci_dev *rcec = rcec_data->rcec;60 61 if ((pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) &&62 rcec_assoc_rciep(rcec, dev))63 rcec_data->user_callback(dev, rcec_data->user_data);64 65 return 0;66}67 68static void walk_rcec(int (*cb)(struct pci_dev *dev, void *data),69 void *userdata)70{71 struct walk_rcec_data *rcec_data = userdata;72 struct pci_dev *rcec = rcec_data->rcec;73 u8 nextbusn, lastbusn;74 struct pci_bus *bus;75 unsigned int bnr;76 77 if (!rcec->rcec_ea)78 return;79 80 /* Walk own bus for bitmap based association */81 pci_walk_bus(rcec->bus, cb, rcec_data);82 83 nextbusn = rcec->rcec_ea->nextbusn;84 lastbusn = rcec->rcec_ea->lastbusn;85 86 /* All RCiEP devices are on the same bus as the RCEC */87 if (nextbusn == 0xff && lastbusn == 0x00)88 return;89 90 for (bnr = nextbusn; bnr <= lastbusn; bnr++) {91 /* No association indicated (PCIe 5.0-1, 7.9.10.3) */92 if (bnr == rcec->bus->number)93 continue;94 95 bus = pci_find_bus(pci_domain_nr(rcec->bus), bnr);96 if (!bus)97 continue;98 99 /* Find RCiEP devices on the given bus ranges */100 pci_walk_bus(bus, cb, rcec_data);101 }102}103 104/**105 * pcie_link_rcec - Link RCiEP devices associated with RCEC.106 * @rcec: RCEC whose RCiEP devices should be linked.107 *108 * Link the given RCEC to each RCiEP device found.109 */110void pcie_link_rcec(struct pci_dev *rcec)111{112 struct walk_rcec_data rcec_data;113 114 if (!rcec->rcec_ea)115 return;116 117 rcec_data.rcec = rcec;118 rcec_data.user_callback = NULL;119 rcec_data.user_data = NULL;120 121 walk_rcec(link_rcec_helper, &rcec_data);122}123 124/**125 * pcie_walk_rcec - Walk RCiEP devices associating with RCEC and call callback.126 * @rcec: RCEC whose RCiEP devices should be walked127 * @cb: Callback to be called for each RCiEP device found128 * @userdata: Arbitrary pointer to be passed to callback129 *130 * Walk the given RCEC. Call the callback on each RCiEP found.131 *132 * If @cb returns anything other than 0, break out.133 */134void pcie_walk_rcec(struct pci_dev *rcec, int (*cb)(struct pci_dev *, void *),135 void *userdata)136{137 struct walk_rcec_data rcec_data;138 139 if (!rcec->rcec_ea)140 return;141 142 rcec_data.rcec = rcec;143 rcec_data.user_callback = cb;144 rcec_data.user_data = userdata;145 146 walk_rcec(walk_rcec_helper, &rcec_data);147}148 149void pci_rcec_init(struct pci_dev *dev)150{151 struct rcec_ea *rcec_ea;152 u32 rcec, hdr, busn;153 u8 ver;154 155 /* Only for Root Complex Event Collectors */156 if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_EC)157 return;158 159 rcec = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_RCEC);160 if (!rcec)161 return;162 163 rcec_ea = kzalloc(sizeof(*rcec_ea), GFP_KERNEL);164 if (!rcec_ea)165 return;166 167 pci_read_config_dword(dev, rcec + PCI_RCEC_RCIEP_BITMAP,168 &rcec_ea->bitmap);169 170 /* Check whether RCEC BUSN register is present */171 pci_read_config_dword(dev, rcec, &hdr);172 ver = PCI_EXT_CAP_VER(hdr);173 if (ver >= PCI_RCEC_BUSN_REG_VER) {174 pci_read_config_dword(dev, rcec + PCI_RCEC_BUSN, &busn);175 rcec_ea->nextbusn = PCI_RCEC_BUSN_NEXT(busn);176 rcec_ea->lastbusn = PCI_RCEC_BUSN_LAST(busn);177 } else {178 /* Avoid later ver check by setting nextbusn */179 rcec_ea->nextbusn = 0xff;180 rcec_ea->lastbusn = 0x00;181 }182 183 dev->rcec_ea = rcec_ea;184}185 186void pci_rcec_exit(struct pci_dev *dev)187{188 kfree(dev->rcec_ea);189 dev->rcec_ea = NULL;190}191