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 static const char * const rp_pio_error_string[] = { 21 "Configuration Request received UR Completion", /* Bit Position 0 */ 22 "Configuration Request received CA Completion", /* Bit Position 1 */ 23 "Configuration Request Completion Timeout", /* Bit Position 2 */ 24 NULL, 25 NULL, 26 NULL, 27 NULL, 28 NULL, 29 "I/O Request received UR Completion", /* Bit Position 8 */ 30 "I/O Request received CA Completion", /* Bit Position 9 */ 31 "I/O Request Completion Timeout", /* Bit Position 10 */ 32 NULL, 33 NULL, 34 NULL, 35 NULL, 36 NULL, 37 "Memory Request received UR Completion", /* Bit Position 16 */ 38 "Memory Request received CA Completion", /* Bit Position 17 */ 39 "Memory Request Completion Timeout", /* Bit Position 18 */ 40 }; 41 42 void pci_save_dpc_state(struct pci_dev *dev) 43 { 44 struct pci_cap_saved_state *save_state; 45 u16 *cap; 46 47 if (!pci_is_pcie(dev)) 48 return; 49 50 save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_DPC); 51 if (!save_state) 52 return; 53 54 cap = (u16 *)&save_state->cap.data[0]; 55 pci_read_config_word(dev, dev->dpc_cap + PCI_EXP_DPC_CTL, cap); 56 } 57 58 void pci_restore_dpc_state(struct pci_dev *dev) 59 { 60 struct pci_cap_saved_state *save_state; 61 u16 *cap; 62 63 if (!pci_is_pcie(dev)) 64 return; 65 66 save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_DPC); 67 if (!save_state) 68 return; 69 70 cap = (u16 *)&save_state->cap.data[0]; 71 pci_write_config_word(dev, dev->dpc_cap + PCI_EXP_DPC_CTL, *cap); 72 } 73 74 static DECLARE_WAIT_QUEUE_HEAD(dpc_completed_waitqueue); 75 76 #ifdef CONFIG_HOTPLUG_PCI_PCIE 77 static bool dpc_completed(struct pci_dev *pdev) 78 { 79 u16 status; 80 81 pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_STATUS, &status); 82 if ((!PCI_POSSIBLE_ERROR(status)) && (status & PCI_EXP_DPC_STATUS_TRIGGER)) 83 return false; 84 85 if (test_bit(PCI_DPC_RECOVERING, &pdev->priv_flags)) 86 return false; 87 88 return true; 89 } 90 91 /** 92 * pci_dpc_recovered - whether DPC triggered and has recovered successfully 93 * @pdev: PCI device 94 * 95 * Return true if DPC was triggered for @pdev and has recovered successfully. 96 * Wait for recovery if it hasn't completed yet. Called from the PCIe hotplug 97 * driver to recognize and ignore Link Down/Up events caused by DPC. 98 */ 99 bool pci_dpc_recovered(struct pci_dev *pdev) 100 { 101 struct pci_host_bridge *host; 102 103 if (!pdev->dpc_cap) 104 return false; 105 106 /* 107 * Synchronization between hotplug and DPC is not supported 108 * if DPC is owned by firmware and EDR is not enabled. 109 */ 110 host = pci_find_host_bridge(pdev->bus); 111 if (!host->native_dpc && !IS_ENABLED(CONFIG_PCIE_EDR)) 112 return false; 113 114 /* 115 * Need a timeout in case DPC never completes due to failure of 116 * dpc_wait_rp_inactive(). The spec doesn't mandate a time limit, 117 * but reports indicate that DPC completes within 4 seconds. 118 */ 119 wait_event_timeout(dpc_completed_waitqueue, dpc_completed(pdev), 120 msecs_to_jiffies(4000)); 121 122 return test_and_clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags); 123 } 124 #endif /* CONFIG_HOTPLUG_PCI_PCIE */ 125 126 static int dpc_wait_rp_inactive(struct pci_dev *pdev) 127 { 128 unsigned long timeout = jiffies + HZ; 129 u16 cap = pdev->dpc_cap, status; 130 131 pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); 132 while (status & PCI_EXP_DPC_RP_BUSY && 133 !time_after(jiffies, timeout)) { 134 msleep(10); 135 pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); 136 } 137 if (status & PCI_EXP_DPC_RP_BUSY) { 138 pci_warn(pdev, "root port still busy\n"); 139 return -EBUSY; 140 } 141 return 0; 142 } 143 144 pci_ers_result_t dpc_reset_link(struct pci_dev *pdev) 145 { 146 pci_ers_result_t ret; 147 u16 cap; 148 149 set_bit(PCI_DPC_RECOVERING, &pdev->priv_flags); 150 151 /* 152 * DPC disables the Link automatically in hardware, so it has 153 * already been reset by the time we get here. 154 */ 155 cap = pdev->dpc_cap; 156 157 /* 158 * Wait until the Link is inactive, then clear DPC Trigger Status 159 * to allow the Port to leave DPC. 160 */ 161 if (!pcie_wait_for_link(pdev, false)) 162 pci_info(pdev, "Data Link Layer Link Active not cleared in 1000 msec\n"); 163 164 if (pdev->dpc_rp_extensions && dpc_wait_rp_inactive(pdev)) { 165 clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags); 166 ret = PCI_ERS_RESULT_DISCONNECT; 167 goto out; 168 } 169 170 pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, 171 PCI_EXP_DPC_STATUS_TRIGGER); 172 173 if (!pcie_wait_for_link(pdev, true)) { 174 pci_info(pdev, "Data Link Layer Link Active not set in 1000 msec\n"); 175 clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags); 176 ret = PCI_ERS_RESULT_DISCONNECT; 177 } else { 178 set_bit(PCI_DPC_RECOVERED, &pdev->priv_flags); 179 ret = PCI_ERS_RESULT_RECOVERED; 180 } 181 out: 182 clear_bit(PCI_DPC_RECOVERING, &pdev->priv_flags); 183 wake_up_all(&dpc_completed_waitqueue); 184 return ret; 185 } 186 187 static void dpc_process_rp_pio_error(struct pci_dev *pdev) 188 { 189 u16 cap = pdev->dpc_cap, dpc_status, first_error; 190 u32 status, mask, sev, syserr, exc, dw0, dw1, dw2, dw3, log, prefix; 191 int i; 192 193 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS, &status); 194 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_MASK, &mask); 195 pci_err(pdev, "rp_pio_status: %#010x, rp_pio_mask: %#010x\n", 196 status, mask); 197 198 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_SEVERITY, &sev); 199 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_SYSERROR, &syserr); 200 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_EXCEPTION, &exc); 201 pci_err(pdev, "RP PIO severity=%#010x, syserror=%#010x, exception=%#010x\n", 202 sev, syserr, exc); 203 204 /* Get First Error Pointer */ 205 pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &dpc_status); 206 first_error = (dpc_status & 0x1f00) >> 8; 207 208 for (i = 0; i < ARRAY_SIZE(rp_pio_error_string); i++) { 209 if ((status & ~mask) & (1 << i)) 210 pci_err(pdev, "[%2d] %s%s\n", i, rp_pio_error_string[i], 211 first_error == i ? " (First)" : ""); 212 } 213 214 if (pdev->dpc_rp_log_size < 4) 215 goto clear_status; 216 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG, 217 &dw0); 218 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 4, 219 &dw1); 220 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 8, 221 &dw2); 222 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 12, 223 &dw3); 224 pci_err(pdev, "TLP Header: %#010x %#010x %#010x %#010x\n", 225 dw0, dw1, dw2, dw3); 226 227 if (pdev->dpc_rp_log_size < 5) 228 goto clear_status; 229 pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_IMPSPEC_LOG, &log); 230 pci_err(pdev, "RP PIO ImpSpec Log %#010x\n", log); 231 232 for (i = 0; i < pdev->dpc_rp_log_size - 5; i++) { 233 pci_read_config_dword(pdev, 234 cap + PCI_EXP_DPC_RP_PIO_TLPPREFIX_LOG, &prefix); 235 pci_err(pdev, "TLP Prefix Header: dw%d, %#010x\n", i, prefix); 236 } 237 clear_status: 238 pci_write_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS, status); 239 } 240 241 static int dpc_get_aer_uncorrect_severity(struct pci_dev *dev, 242 struct aer_err_info *info) 243 { 244 int pos = dev->aer_cap; 245 u32 status, mask, sev; 246 247 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status); 248 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, &mask); 249 status &= ~mask; 250 if (!status) 251 return 0; 252 253 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &sev); 254 status &= sev; 255 if (status) 256 info->severity = AER_FATAL; 257 else 258 info->severity = AER_NONFATAL; 259 260 return 1; 261 } 262 263 void dpc_process_error(struct pci_dev *pdev) 264 { 265 u16 cap = pdev->dpc_cap, status, source, reason, ext_reason; 266 struct aer_err_info info; 267 268 pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); 269 pci_read_config_word(pdev, cap + PCI_EXP_DPC_SOURCE_ID, &source); 270 271 pci_info(pdev, "containment event, status:%#06x source:%#06x\n", 272 status, source); 273 274 reason = (status & PCI_EXP_DPC_STATUS_TRIGGER_RSN) >> 1; 275 ext_reason = (status & PCI_EXP_DPC_STATUS_TRIGGER_RSN_EXT) >> 5; 276 pci_warn(pdev, "%s detected\n", 277 (reason == 0) ? "unmasked uncorrectable error" : 278 (reason == 1) ? "ERR_NONFATAL" : 279 (reason == 2) ? "ERR_FATAL" : 280 (ext_reason == 0) ? "RP PIO error" : 281 (ext_reason == 1) ? "software trigger" : 282 "reserved error"); 283 284 /* show RP PIO error detail information */ 285 if (pdev->dpc_rp_extensions && reason == 3 && ext_reason == 0) 286 dpc_process_rp_pio_error(pdev); 287 else if (reason == 0 && 288 dpc_get_aer_uncorrect_severity(pdev, &info) && 289 aer_get_device_error_info(pdev, &info)) { 290 aer_print_error(pdev, &info); 291 pci_aer_clear_nonfatal_status(pdev); 292 pci_aer_clear_fatal_status(pdev); 293 } 294 } 295 296 static irqreturn_t dpc_handler(int irq, void *context) 297 { 298 struct pci_dev *pdev = context; 299 300 dpc_process_error(pdev); 301 302 /* We configure DPC so it only triggers on ERR_FATAL */ 303 pcie_do_recovery(pdev, pci_channel_io_frozen, dpc_reset_link); 304 305 return IRQ_HANDLED; 306 } 307 308 static irqreturn_t dpc_irq(int irq, void *context) 309 { 310 struct pci_dev *pdev = context; 311 u16 cap = pdev->dpc_cap, status; 312 313 pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); 314 315 if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT) || PCI_POSSIBLE_ERROR(status)) 316 return IRQ_NONE; 317 318 pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, 319 PCI_EXP_DPC_STATUS_INTERRUPT); 320 if (status & PCI_EXP_DPC_STATUS_TRIGGER) 321 return IRQ_WAKE_THREAD; 322 return IRQ_HANDLED; 323 } 324 325 void pci_dpc_init(struct pci_dev *pdev) 326 { 327 u16 cap; 328 329 pdev->dpc_cap = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC); 330 if (!pdev->dpc_cap) 331 return; 332 333 pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CAP, &cap); 334 if (!(cap & PCI_EXP_DPC_CAP_RP_EXT)) 335 return; 336 337 pdev->dpc_rp_extensions = true; 338 339 /* Quirks may set dpc_rp_log_size if device or firmware is buggy */ 340 if (!pdev->dpc_rp_log_size) { 341 pdev->dpc_rp_log_size = 342 (cap & PCI_EXP_DPC_RP_PIO_LOG_SIZE) >> 8; 343 if (pdev->dpc_rp_log_size < 4 || pdev->dpc_rp_log_size > 9) { 344 pci_err(pdev, "RP PIO log size %u is invalid\n", 345 pdev->dpc_rp_log_size); 346 pdev->dpc_rp_log_size = 0; 347 } 348 } 349 } 350 351 #define FLAG(x, y) (((x) & (y)) ? '+' : '-') 352 static int dpc_probe(struct pcie_device *dev) 353 { 354 struct pci_dev *pdev = dev->port; 355 struct device *device = &dev->device; 356 int status; 357 u16 ctl, cap; 358 359 if (!pcie_aer_is_native(pdev) && !pcie_ports_dpc_native) 360 return -ENOTSUPP; 361 362 status = devm_request_threaded_irq(device, dev->irq, dpc_irq, 363 dpc_handler, IRQF_SHARED, 364 "pcie-dpc", pdev); 365 if (status) { 366 pci_warn(pdev, "request IRQ%d failed: %d\n", dev->irq, 367 status); 368 return status; 369 } 370 371 pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CAP, &cap); 372 pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, &ctl); 373 374 ctl = (ctl & 0xfff4) | PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN; 375 pci_write_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, ctl); 376 pci_info(pdev, "enabled with IRQ %d\n", dev->irq); 377 378 pci_info(pdev, "error containment capabilities: Int Msg #%d, RPExt%c PoisonedTLP%c SwTrigger%c RP PIO Log %d, DL_ActiveErr%c\n", 379 cap & PCI_EXP_DPC_IRQ, FLAG(cap, PCI_EXP_DPC_CAP_RP_EXT), 380 FLAG(cap, PCI_EXP_DPC_CAP_POISONED_TLP), 381 FLAG(cap, PCI_EXP_DPC_CAP_SW_TRIGGER), pdev->dpc_rp_log_size, 382 FLAG(cap, PCI_EXP_DPC_CAP_DL_ACTIVE)); 383 384 pci_add_ext_cap_save_buffer(pdev, PCI_EXT_CAP_ID_DPC, sizeof(u16)); 385 return status; 386 } 387 388 static void dpc_remove(struct pcie_device *dev) 389 { 390 struct pci_dev *pdev = dev->port; 391 u16 ctl; 392 393 pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, &ctl); 394 ctl &= ~(PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN); 395 pci_write_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, ctl); 396 } 397 398 static struct pcie_port_service_driver dpcdriver = { 399 .name = "dpc", 400 .port_type = PCIE_ANY_PORT, 401 .service = PCIE_PORT_SERVICE_DPC, 402 .probe = dpc_probe, 403 .remove = dpc_remove, 404 }; 405 406 int __init pcie_dpc_init(void) 407 { 408 return pcie_port_service_register(&dpcdriver); 409 } 410