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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 | // 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; } |