1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * PCI Express Downstream Port Containment services driver 4 * Author: Keith Busch <keith.busch@intel.com> 5 * 6 * Copyright (C) 2016 Intel Corp. 7 */ 8 9 #define dev_fmt(fmt) "DPC: " fmt 10 11 #include <linux/aer.h> 12 #include <linux/delay.h> 13 #include <linux/interrupt.h> 14 #include <linux/init.h> 15 #include <linux/pci.h> 16 17 #include "portdrv.h" 18 #include "../pci.h" 19 20 struct dpc_dev { 21 struct pcie_device *dev; 22 u16 cap_pos; 23 bool rp_extensions; 24 u8 rp_log_size; 25 }; 26 27 static const char * const rp_pio_error_string[] = { 28 "Configuration Request received UR Completion", /* Bit Position 0 */ 29 "Configuration Request received CA Completion", /* Bit Position 1 */ 30 "Configuration Request Completion Timeout", /* Bit Position 2 */ 31 NULL, 32 NULL, 33 NULL, 34 NULL, 35 NULL, 36 "I/O Request received UR Completion", /* Bit Position 8 */ 37 "I/O Request received CA Completion", /* Bit Position 9 */ 38 "I/O Request Completion Timeout", /* Bit Position 10 */ 39 NULL, 40 NULL, 41 NULL, 42 NULL, 43 NULL, 44 "Memory Request received UR Completion", /* Bit Position 16 */ 45 "Memory Request received CA Completion", /* Bit Position 17 */ 46 "Memory Request Completion Timeout", /* Bit Position 18 */ 47 }; 48 49 static struct dpc_dev *to_dpc_dev(struct pci_dev *dev) 50 { 51 struct device *device; 52 53 device = pcie_port_find_device(dev, PCIE_PORT_SERVICE_DPC); 54 if (!device) 55 return NULL; 56 return get_service_data(to_pcie_device(device)); 57 } 58 59 void pci_save_dpc_state(struct pci_dev *dev) 60 { 61 struct dpc_dev *dpc; 62 struct pci_cap_saved_state *save_state; 63 u16 *cap; 64 65 if (!pci_is_pcie(dev)) 66 return; 67 68 dpc = to_dpc_dev(dev); 69 if (!dpc) 70 return; 71 72 save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_DPC); 73 if (!save_state) 74 return; 75 76 cap = (u16 *)&save_state->cap.data[0]; 77 pci_read_config_word(dev, dpc->cap_pos + PCI_EXP_DPC_CTL, cap); 78 } 79 80 void pci_restore_dpc_state(struct pci_dev *dev) 81 { 82 struct dpc_dev *dpc; 83 struct pci_cap_saved_state *save_state; 84 u16 *cap; 85 86 if (!pci_is_pcie(dev)) 87 return; 88 89 dpc = to_dpc_dev(dev); 90 if (!dpc) 91 return; 92 93 save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_DPC); 94 if (!save_state) 95 return; 96 97 cap = (u16 *)&save_state->cap.data[0]; 98 pci_write_config_word(dev, dpc->cap_pos + PCI_EXP_DPC_CTL, *cap); 99 } 100 101 static int dpc_wait_rp_inactive(struct dpc_dev *dpc) 102 { 103 unsigned long timeout = jiffies + HZ; 104 struct pci_dev *pdev = dpc->dev->port; 105 u16 cap = dpc->cap_pos, status; 106 107 pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); 108 while (status & PCI_EXP_DPC_RP_BUSY && 109 !time_after(jiffies, timeout)) { 110 msleep(10); 111 pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); 112 } 113 if (status & PCI_EXP_DPC_RP_BUSY) { 114 pci_warn(pdev, "root port still busy\n"); 115 return -EBUSY; 116 } 117 return 0; 118 } 119 120 static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev) 121 { 122 struct dpc_dev *dpc; 123 u16 cap; 124 125 /* 126 * DPC disables the Link automatically in hardware, so it has 127 * already been reset by the time we get here. 128 */ 129 dpc = to_dpc_dev(pdev); 130 cap = dpc->cap_pos; 131 132 /* 133 * Wait until the Link is inactive, then clear DPC Trigger Status 134 * to allow the Port to leave DPC. 135 */ 136 pcie_wait_for_link(pdev, false); 137 138 if (dpc->rp_extensions && dpc_wait_rp_inactive(dpc)) 139 return PCI_ERS_RESULT_DISCONNECT; 140 141 pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, 142 PCI_EXP_DPC_STATUS_TRIGGER); 143 144 if (!pcie_wait_for_link(pdev, true)) 145 return PCI_ERS_RESULT_DISCONNECT; 146 147 return PCI_ERS_RESULT_RECOVERED; 148 } 149 150 static void dpc_process_rp_pio_error(struct dpc_dev *dpc) 151 { 152 struct pci_dev *pdev = dpc->dev->port; 153 u16 cap = dpc->cap_pos, dpc_status, first_error; 154 u32 status, mask, sev, syserr, exc, dw0, dw1, dw2, dw3, log, prefix; 155 int i; 156 157 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS, &status); 158 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_MASK, &mask); 159 pci_err(pdev, "rp_pio_status: %#010x, rp_pio_mask: %#010x\n", 160 status, mask); 161 162 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_SEVERITY, &sev); 163 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_SYSERROR, &syserr); 164 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_EXCEPTION, &exc); 165 pci_err(pdev, "RP PIO severity=%#010x, syserror=%#010x, exception=%#010x\n", 166 sev, syserr, exc); 167 168 /* Get First Error Pointer */ 169 pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &dpc_status); 170 first_error = (dpc_status & 0x1f00) >> 8; 171 172 for (i = 0; i < ARRAY_SIZE(rp_pio_error_string); i++) { 173 if ((status & ~mask) & (1 << i)) 174 pci_err(pdev, "[%2d] %s%s\n", i, rp_pio_error_string[i], 175 first_error == i ? " (First)" : ""); 176 } 177 178 if (dpc->rp_log_size < 4) 179 goto clear_status; 180 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG, 181 &dw0); 182 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 4, 183 &dw1); 184 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 8, 185 &dw2); 186 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 12, 187 &dw3); 188 pci_err(pdev, "TLP Header: %#010x %#010x %#010x %#010x\n", 189 dw0, dw1, dw2, dw3); 190 191 if (dpc->rp_log_size < 5) 192 goto clear_status; 193 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_IMPSPEC_LOG, &log); 194 pci_err(pdev, "RP PIO ImpSpec Log %#010x\n", log); 195 196 for (i = 0; i < dpc->rp_log_size - 5; i++) { 197 pci_read_config_dword(pdev, 198 cap + PCI_EXP_DPC_RP_PIO_TLPPREFIX_LOG, &prefix); 199 pci_err(pdev, "TLP Prefix Header: dw%d, %#010x\n", i, prefix); 200 } 201 clear_status: 202 pci_write_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS, status); 203 } 204 205 static int dpc_get_aer_uncorrect_severity(struct pci_dev *dev, 206 struct aer_err_info *info) 207 { 208 int pos = dev->aer_cap; 209 u32 status, mask, sev; 210 211 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status); 212 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, &mask); 213 status &= ~mask; 214 if (!status) 215 return 0; 216 217 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &sev); 218 status &= sev; 219 if (status) 220 info->severity = AER_FATAL; 221 else 222 info->severity = AER_NONFATAL; 223 224 return 1; 225 } 226 227 static irqreturn_t dpc_handler(int irq, void *context) 228 { 229 struct aer_err_info info; 230 struct dpc_dev *dpc = context; 231 struct pci_dev *pdev = dpc->dev->port; 232 u16 cap = dpc->cap_pos, status, source, reason, ext_reason; 233 234 pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); 235 pci_read_config_word(pdev, cap + PCI_EXP_DPC_SOURCE_ID, &source); 236 237 pci_info(pdev, "containment event, status:%#06x source:%#06x\n", 238 status, source); 239 240 reason = (status & PCI_EXP_DPC_STATUS_TRIGGER_RSN) >> 1; 241 ext_reason = (status & PCI_EXP_DPC_STATUS_TRIGGER_RSN_EXT) >> 5; 242 pci_warn(pdev, "%s detected\n", 243 (reason == 0) ? "unmasked uncorrectable error" : 244 (reason == 1) ? "ERR_NONFATAL" : 245 (reason == 2) ? "ERR_FATAL" : 246 (ext_reason == 0) ? "RP PIO error" : 247 (ext_reason == 1) ? "software trigger" : 248 "reserved error"); 249 250 /* show RP PIO error detail information */ 251 if (dpc->rp_extensions && reason == 3 && ext_reason == 0) 252 dpc_process_rp_pio_error(dpc); 253 else if (reason == 0 && 254 dpc_get_aer_uncorrect_severity(pdev, &info) && 255 aer_get_device_error_info(pdev, &info)) { 256 aer_print_error(pdev, &info); 257 pci_cleanup_aer_uncorrect_error_status(pdev); 258 pci_aer_clear_fatal_status(pdev); 259 } 260 261 /* We configure DPC so it only triggers on ERR_FATAL */ 262 pcie_do_recovery(pdev, pci_channel_io_frozen, PCIE_PORT_SERVICE_DPC); 263 264 return IRQ_HANDLED; 265 } 266 267 static irqreturn_t dpc_irq(int irq, void *context) 268 { 269 struct dpc_dev *dpc = (struct dpc_dev *)context; 270 struct pci_dev *pdev = dpc->dev->port; 271 u16 cap = dpc->cap_pos, status; 272 273 pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); 274 275 if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT) || status == (u16)(~0)) 276 return IRQ_NONE; 277 278 pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, 279 PCI_EXP_DPC_STATUS_INTERRUPT); 280 if (status & PCI_EXP_DPC_STATUS_TRIGGER) 281 return IRQ_WAKE_THREAD; 282 return IRQ_HANDLED; 283 } 284 285 #define FLAG(x, y) (((x) & (y)) ? '+' : '-') 286 static int dpc_probe(struct pcie_device *dev) 287 { 288 struct dpc_dev *dpc; 289 struct pci_dev *pdev = dev->port; 290 struct device *device = &dev->device; 291 int status; 292 u16 ctl, cap; 293 294 if (pcie_aer_get_firmware_first(pdev)) 295 return -ENOTSUPP; 296 297 dpc = devm_kzalloc(device, sizeof(*dpc), GFP_KERNEL); 298 if (!dpc) 299 return -ENOMEM; 300 301 dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC); 302 dpc->dev = dev; 303 set_service_data(dev, dpc); 304 305 status = devm_request_threaded_irq(device, dev->irq, dpc_irq, 306 dpc_handler, IRQF_SHARED, 307 "pcie-dpc", dpc); 308 if (status) { 309 pci_warn(pdev, "request IRQ%d failed: %d\n", dev->irq, 310 status); 311 return status; 312 } 313 314 pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap); 315 pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl); 316 317 dpc->rp_extensions = (cap & PCI_EXP_DPC_CAP_RP_EXT); 318 if (dpc->rp_extensions) { 319 dpc->rp_log_size = (cap & PCI_EXP_DPC_RP_PIO_LOG_SIZE) >> 8; 320 if (dpc->rp_log_size < 4 || dpc->rp_log_size > 9) { 321 pci_err(pdev, "RP PIO log size %u is invalid\n", 322 dpc->rp_log_size); 323 dpc->rp_log_size = 0; 324 } 325 } 326 327 ctl = (ctl & 0xfff4) | PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN; 328 pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl); 329 330 pci_info(pdev, "error containment capabilities: Int Msg #%d, RPExt%c PoisonedTLP%c SwTrigger%c RP PIO Log %d, DL_ActiveErr%c\n", 331 cap & PCI_EXP_DPC_IRQ, FLAG(cap, PCI_EXP_DPC_CAP_RP_EXT), 332 FLAG(cap, PCI_EXP_DPC_CAP_POISONED_TLP), 333 FLAG(cap, PCI_EXP_DPC_CAP_SW_TRIGGER), dpc->rp_log_size, 334 FLAG(cap, PCI_EXP_DPC_CAP_DL_ACTIVE)); 335 336 pci_add_ext_cap_save_buffer(pdev, PCI_EXT_CAP_ID_DPC, sizeof(u16)); 337 return status; 338 } 339 340 static void dpc_remove(struct pcie_device *dev) 341 { 342 struct dpc_dev *dpc = get_service_data(dev); 343 struct pci_dev *pdev = dev->port; 344 u16 ctl; 345 346 pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl); 347 ctl &= ~(PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN); 348 pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl); 349 } 350 351 static struct pcie_port_service_driver dpcdriver = { 352 .name = "dpc", 353 .port_type = PCIE_ANY_PORT, 354 .service = PCIE_PORT_SERVICE_DPC, 355 .probe = dpc_probe, 356 .remove = dpc_remove, 357 .reset_link = dpc_reset_link, 358 }; 359 360 int __init pcie_dpc_init(void) 361 { 362 return pcie_port_service_register(&dpcdriver); 363 } 364