Sean V Kelley | 9065563 | 2020-11-20 16:10:24 -0800 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Root Complex Event Collector Support |
| 4 | * |
| 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 | |
Sean V Kelley | 507b460 | 2020-11-20 16:10:32 -0800 | [diff] [blame] | 18 | struct walk_rcec_data { |
| 19 | struct pci_dev *rcec; |
| 20 | int (*user_callback)(struct pci_dev *dev, void *data); |
| 21 | void *user_data; |
| 22 | }; |
| 23 | |
| 24 | static 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) |
Qiuxu Zhuo | d9b7eae | 2021-02-22 09:17:17 +0800 | [diff] [blame] | 35 | if (devn == PCI_SLOT(rciep->devfn)) |
Sean V Kelley | 507b460 | 2020-11-20 16:10:32 -0800 | [diff] [blame] | 36 | return true; |
| 37 | |
| 38 | return false; |
| 39 | } |
| 40 | |
| 41 | static 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 | |
Sean V Kelley | af11355 | 2020-11-20 16:10:34 -0800 | [diff] [blame] | 56 | static 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 | |
Sean V Kelley | 507b460 | 2020-11-20 16:10:32 -0800 | [diff] [blame] | 68 | static 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 | */ |
| 110 | void 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 | |
Sean V Kelley | af11355 | 2020-11-20 16:10:34 -0800 | [diff] [blame] | 124 | /** |
| 125 | * pcie_walk_rcec - Walk RCiEP devices associating with RCEC and call callback. |
| 126 | * @rcec: RCEC whose RCiEP devices should be walked |
| 127 | * @cb: Callback to be called for each RCiEP device found |
| 128 | * @userdata: Arbitrary pointer to be passed to callback |
| 129 | * |
| 130 | * Walk the given RCEC. Call the callback on each RCiEP found. |
| 131 | * |
| 132 | * If @cb returns anything other than 0, break out. |
| 133 | */ |
| 134 | void 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 | |
Sean V Kelley | 9065563 | 2020-11-20 16:10:24 -0800 | [diff] [blame] | 149 | void 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 | |
| 186 | void pci_rcec_exit(struct pci_dev *dev) |
| 187 | { |
| 188 | kfree(dev->rcec_ea); |
| 189 | dev->rcec_ea = NULL; |
| 190 | } |