1 /* 2 * Standalone EHCI usb debug driver 3 * 4 * Originally written by: 5 * Eric W. Biederman" <ebiederm@xmission.com> and 6 * Yinghai Lu <yhlu.kernel@gmail.com> 7 * 8 * Changes for early/late printk and HW errata: 9 * Jason Wessel <jason.wessel@windriver.com> 10 * Copyright (C) 2009 Wind River Systems, Inc. 11 * 12 */ 13 14 #include <linux/console.h> 15 #include <linux/errno.h> 16 #include <linux/module.h> 17 #include <linux/pci_regs.h> 18 #include <linux/pci_ids.h> 19 #include <linux/usb/ch9.h> 20 #include <linux/usb/ehci_def.h> 21 #include <linux/delay.h> 22 #include <linux/serial_core.h> 23 #include <linux/kconfig.h> 24 #include <linux/kgdb.h> 25 #include <linux/kthread.h> 26 #include <asm/io.h> 27 #include <asm/pci-direct.h> 28 #include <asm/fixmap.h> 29 30 /* The code here is intended to talk directly to the EHCI debug port 31 * and does not require that you have any kind of USB host controller 32 * drivers or USB device drivers compiled into the kernel. 33 * 34 * If you make a change to anything in here, the following test cases 35 * need to pass where a USB debug device works in the following 36 * configurations. 37 * 38 * 1. boot args: earlyprintk=dbgp 39 * o kernel compiled with # CONFIG_USB_EHCI_HCD is not set 40 * o kernel compiled with CONFIG_USB_EHCI_HCD=y 41 * 2. boot args: earlyprintk=dbgp,keep 42 * o kernel compiled with # CONFIG_USB_EHCI_HCD is not set 43 * o kernel compiled with CONFIG_USB_EHCI_HCD=y 44 * 3. boot args: earlyprintk=dbgp console=ttyUSB0 45 * o kernel has CONFIG_USB_EHCI_HCD=y and 46 * CONFIG_USB_SERIAL_DEBUG=y 47 * 4. boot args: earlyprintk=vga,dbgp 48 * o kernel compiled with # CONFIG_USB_EHCI_HCD is not set 49 * o kernel compiled with CONFIG_USB_EHCI_HCD=y 50 * 51 * For the 4th configuration you can turn on or off the DBGP_DEBUG 52 * such that you can debug the dbgp device's driver code. 53 */ 54 55 static int dbgp_phys_port = 1; 56 57 static struct ehci_caps __iomem *ehci_caps; 58 static struct ehci_regs __iomem *ehci_regs; 59 static struct ehci_dbg_port __iomem *ehci_debug; 60 static int dbgp_not_safe; /* Cannot use debug device during ehci reset */ 61 static unsigned int dbgp_endpoint_out; 62 static unsigned int dbgp_endpoint_in; 63 64 struct ehci_dev { 65 u32 bus; 66 u32 slot; 67 u32 func; 68 }; 69 70 static struct ehci_dev ehci_dev; 71 72 #define USB_DEBUG_DEVNUM 127 73 74 #ifdef DBGP_DEBUG 75 #define dbgp_printk printk 76 static void dbgp_ehci_status(char *str) 77 { 78 if (!ehci_debug) 79 return; 80 dbgp_printk("dbgp: %s\n", str); 81 dbgp_printk(" Debug control: %08x", readl(&ehci_debug->control)); 82 dbgp_printk(" ehci cmd : %08x", readl(&ehci_regs->command)); 83 dbgp_printk(" ehci conf flg: %08x\n", 84 readl(&ehci_regs->configured_flag)); 85 dbgp_printk(" ehci status : %08x", readl(&ehci_regs->status)); 86 dbgp_printk(" ehci portsc : %08x\n", 87 readl(&ehci_regs->port_status[dbgp_phys_port - 1])); 88 } 89 #else 90 static inline void dbgp_ehci_status(char *str) { } 91 static inline void dbgp_printk(const char *fmt, ...) { } 92 #endif 93 94 static inline u32 dbgp_len_update(u32 x, u32 len) 95 { 96 return (x & ~0x0f) | (len & 0x0f); 97 } 98 99 #ifdef CONFIG_KGDB 100 static struct kgdb_io kgdbdbgp_io_ops; 101 #define dbgp_kgdb_mode (dbg_io_ops == &kgdbdbgp_io_ops) 102 #else 103 #define dbgp_kgdb_mode (0) 104 #endif 105 106 /* Local version of HC_LENGTH macro as ehci struct is not available here */ 107 #define EARLY_HC_LENGTH(p) (0x00ff & (p)) /* bits 7 : 0 */ 108 109 /* 110 * USB Packet IDs (PIDs) 111 */ 112 113 /* token */ 114 #define USB_PID_OUT 0xe1 115 #define USB_PID_IN 0x69 116 #define USB_PID_SOF 0xa5 117 #define USB_PID_SETUP 0x2d 118 /* handshake */ 119 #define USB_PID_ACK 0xd2 120 #define USB_PID_NAK 0x5a 121 #define USB_PID_STALL 0x1e 122 #define USB_PID_NYET 0x96 123 /* data */ 124 #define USB_PID_DATA0 0xc3 125 #define USB_PID_DATA1 0x4b 126 #define USB_PID_DATA2 0x87 127 #define USB_PID_MDATA 0x0f 128 /* Special */ 129 #define USB_PID_PREAMBLE 0x3c 130 #define USB_PID_ERR 0x3c 131 #define USB_PID_SPLIT 0x78 132 #define USB_PID_PING 0xb4 133 #define USB_PID_UNDEF_0 0xf0 134 135 #define USB_PID_DATA_TOGGLE 0x88 136 #define DBGP_CLAIM (DBGP_OWNER | DBGP_ENABLED | DBGP_INUSE) 137 138 #define PCI_CAP_ID_EHCI_DEBUG 0xa 139 140 #define HUB_ROOT_RESET_TIME 50 /* times are in msec */ 141 #define HUB_SHORT_RESET_TIME 10 142 #define HUB_LONG_RESET_TIME 200 143 #define HUB_RESET_TIMEOUT 500 144 145 #define DBGP_MAX_PACKET 8 146 #define DBGP_TIMEOUT (250 * 1000) 147 #define DBGP_LOOPS 1000 148 149 static inline u32 dbgp_pid_write_update(u32 x, u32 tok) 150 { 151 static int data0 = USB_PID_DATA1; 152 data0 ^= USB_PID_DATA_TOGGLE; 153 return (x & 0xffff0000) | (data0 << 8) | (tok & 0xff); 154 } 155 156 static inline u32 dbgp_pid_read_update(u32 x, u32 tok) 157 { 158 return (x & 0xffff0000) | (USB_PID_DATA0 << 8) | (tok & 0xff); 159 } 160 161 static int dbgp_wait_until_complete(void) 162 { 163 u32 ctrl; 164 int loop = DBGP_TIMEOUT; 165 166 do { 167 ctrl = readl(&ehci_debug->control); 168 /* Stop when the transaction is finished */ 169 if (ctrl & DBGP_DONE) 170 break; 171 udelay(1); 172 } while (--loop > 0); 173 174 if (!loop) 175 return -DBGP_TIMEOUT; 176 177 /* 178 * Now that we have observed the completed transaction, 179 * clear the done bit. 180 */ 181 writel(ctrl | DBGP_DONE, &ehci_debug->control); 182 return (ctrl & DBGP_ERROR) ? -DBGP_ERRCODE(ctrl) : DBGP_LEN(ctrl); 183 } 184 185 static inline void dbgp_mdelay(int ms) 186 { 187 int i; 188 189 while (ms--) { 190 for (i = 0; i < 1000; i++) 191 outb(0x1, 0x80); 192 } 193 } 194 195 static void dbgp_breath(void) 196 { 197 /* Sleep to give the debug port a chance to breathe */ 198 } 199 200 static int dbgp_wait_until_done(unsigned ctrl, int loop) 201 { 202 u32 pids, lpid; 203 int ret; 204 205 retry: 206 writel(ctrl | DBGP_GO, &ehci_debug->control); 207 ret = dbgp_wait_until_complete(); 208 pids = readl(&ehci_debug->pids); 209 lpid = DBGP_PID_GET(pids); 210 211 if (ret < 0) { 212 /* A -DBGP_TIMEOUT failure here means the device has 213 * failed, perhaps because it was unplugged, in which 214 * case we do not want to hang the system so the dbgp 215 * will be marked as unsafe to use. EHCI reset is the 216 * only way to recover if you unplug the dbgp device. 217 */ 218 if (ret == -DBGP_TIMEOUT && !dbgp_not_safe) 219 dbgp_not_safe = 1; 220 if (ret == -DBGP_ERR_BAD && --loop > 0) 221 goto retry; 222 return ret; 223 } 224 225 /* 226 * If the port is getting full or it has dropped data 227 * start pacing ourselves, not necessary but it's friendly. 228 */ 229 if ((lpid == USB_PID_NAK) || (lpid == USB_PID_NYET)) 230 dbgp_breath(); 231 232 /* If I get a NACK reissue the transmission */ 233 if (lpid == USB_PID_NAK) { 234 if (--loop > 0) 235 goto retry; 236 } 237 238 return ret; 239 } 240 241 static inline void dbgp_set_data(const void *buf, int size) 242 { 243 const unsigned char *bytes = buf; 244 u32 lo, hi; 245 int i; 246 247 lo = hi = 0; 248 for (i = 0; i < 4 && i < size; i++) 249 lo |= bytes[i] << (8*i); 250 for (; i < 8 && i < size; i++) 251 hi |= bytes[i] << (8*(i - 4)); 252 writel(lo, &ehci_debug->data03); 253 writel(hi, &ehci_debug->data47); 254 } 255 256 static inline void dbgp_get_data(void *buf, int size) 257 { 258 unsigned char *bytes = buf; 259 u32 lo, hi; 260 int i; 261 262 lo = readl(&ehci_debug->data03); 263 hi = readl(&ehci_debug->data47); 264 for (i = 0; i < 4 && i < size; i++) 265 bytes[i] = (lo >> (8*i)) & 0xff; 266 for (; i < 8 && i < size; i++) 267 bytes[i] = (hi >> (8*(i - 4))) & 0xff; 268 } 269 270 static int dbgp_bulk_write(unsigned devnum, unsigned endpoint, 271 const char *bytes, int size) 272 { 273 int ret; 274 u32 addr; 275 u32 pids, ctrl; 276 277 if (size > DBGP_MAX_PACKET) 278 return -1; 279 280 addr = DBGP_EPADDR(devnum, endpoint); 281 282 pids = readl(&ehci_debug->pids); 283 pids = dbgp_pid_write_update(pids, USB_PID_OUT); 284 285 ctrl = readl(&ehci_debug->control); 286 ctrl = dbgp_len_update(ctrl, size); 287 ctrl |= DBGP_OUT; 288 ctrl |= DBGP_GO; 289 290 dbgp_set_data(bytes, size); 291 writel(addr, &ehci_debug->address); 292 writel(pids, &ehci_debug->pids); 293 ret = dbgp_wait_until_done(ctrl, DBGP_LOOPS); 294 295 return ret; 296 } 297 298 static int dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data, 299 int size, int loops) 300 { 301 u32 pids, addr, ctrl; 302 int ret; 303 304 if (size > DBGP_MAX_PACKET) 305 return -1; 306 307 addr = DBGP_EPADDR(devnum, endpoint); 308 309 pids = readl(&ehci_debug->pids); 310 pids = dbgp_pid_read_update(pids, USB_PID_IN); 311 312 ctrl = readl(&ehci_debug->control); 313 ctrl = dbgp_len_update(ctrl, size); 314 ctrl &= ~DBGP_OUT; 315 ctrl |= DBGP_GO; 316 317 writel(addr, &ehci_debug->address); 318 writel(pids, &ehci_debug->pids); 319 ret = dbgp_wait_until_done(ctrl, loops); 320 if (ret < 0) 321 return ret; 322 323 if (size > ret) 324 size = ret; 325 dbgp_get_data(data, size); 326 return ret; 327 } 328 329 static int dbgp_control_msg(unsigned devnum, int requesttype, 330 int request, int value, int index, void *data, int size) 331 { 332 u32 pids, addr, ctrl; 333 struct usb_ctrlrequest req; 334 int read; 335 int ret; 336 337 read = (requesttype & USB_DIR_IN) != 0; 338 if (size > (read ? DBGP_MAX_PACKET : 0)) 339 return -1; 340 341 /* Compute the control message */ 342 req.bRequestType = requesttype; 343 req.bRequest = request; 344 req.wValue = cpu_to_le16(value); 345 req.wIndex = cpu_to_le16(index); 346 req.wLength = cpu_to_le16(size); 347 348 pids = DBGP_PID_SET(USB_PID_DATA0, USB_PID_SETUP); 349 addr = DBGP_EPADDR(devnum, 0); 350 351 ctrl = readl(&ehci_debug->control); 352 ctrl = dbgp_len_update(ctrl, sizeof(req)); 353 ctrl |= DBGP_OUT; 354 ctrl |= DBGP_GO; 355 356 /* Send the setup message */ 357 dbgp_set_data(&req, sizeof(req)); 358 writel(addr, &ehci_debug->address); 359 writel(pids, &ehci_debug->pids); 360 ret = dbgp_wait_until_done(ctrl, DBGP_LOOPS); 361 if (ret < 0) 362 return ret; 363 364 /* Read the result */ 365 return dbgp_bulk_read(devnum, 0, data, size, DBGP_LOOPS); 366 } 367 368 /* Find a PCI capability */ 369 static u32 __init find_cap(u32 num, u32 slot, u32 func, int cap) 370 { 371 u8 pos; 372 int bytes; 373 374 if (!(read_pci_config_16(num, slot, func, PCI_STATUS) & 375 PCI_STATUS_CAP_LIST)) 376 return 0; 377 378 pos = read_pci_config_byte(num, slot, func, PCI_CAPABILITY_LIST); 379 for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) { 380 u8 id; 381 382 pos &= ~3; 383 id = read_pci_config_byte(num, slot, func, pos+PCI_CAP_LIST_ID); 384 if (id == 0xff) 385 break; 386 if (id == cap) 387 return pos; 388 389 pos = read_pci_config_byte(num, slot, func, 390 pos+PCI_CAP_LIST_NEXT); 391 } 392 return 0; 393 } 394 395 static u32 __init __find_dbgp(u32 bus, u32 slot, u32 func) 396 { 397 u32 class; 398 399 class = read_pci_config(bus, slot, func, PCI_CLASS_REVISION); 400 if ((class >> 8) != PCI_CLASS_SERIAL_USB_EHCI) 401 return 0; 402 403 return find_cap(bus, slot, func, PCI_CAP_ID_EHCI_DEBUG); 404 } 405 406 static u32 __init find_dbgp(int ehci_num, u32 *rbus, u32 *rslot, u32 *rfunc) 407 { 408 u32 bus, slot, func; 409 410 for (bus = 0; bus < 256; bus++) { 411 for (slot = 0; slot < 32; slot++) { 412 for (func = 0; func < 8; func++) { 413 unsigned cap; 414 415 cap = __find_dbgp(bus, slot, func); 416 417 if (!cap) 418 continue; 419 if (ehci_num-- != 0) 420 continue; 421 *rbus = bus; 422 *rslot = slot; 423 *rfunc = func; 424 return cap; 425 } 426 } 427 } 428 return 0; 429 } 430 431 static int dbgp_ehci_startup(void) 432 { 433 u32 ctrl, cmd, status; 434 int loop; 435 436 /* Claim ownership, but do not enable yet */ 437 ctrl = readl(&ehci_debug->control); 438 ctrl |= DBGP_OWNER; 439 ctrl &= ~(DBGP_ENABLED | DBGP_INUSE); 440 writel(ctrl, &ehci_debug->control); 441 udelay(1); 442 443 dbgp_ehci_status("EHCI startup"); 444 /* Start the ehci running */ 445 cmd = readl(&ehci_regs->command); 446 cmd &= ~(CMD_LRESET | CMD_IAAD | CMD_PSE | CMD_ASE | CMD_RESET); 447 cmd |= CMD_RUN; 448 writel(cmd, &ehci_regs->command); 449 450 /* Ensure everything is routed to the EHCI */ 451 writel(FLAG_CF, &ehci_regs->configured_flag); 452 453 /* Wait until the controller is no longer halted */ 454 loop = 1000; 455 do { 456 status = readl(&ehci_regs->status); 457 if (!(status & STS_HALT)) 458 break; 459 udelay(1); 460 } while (--loop > 0); 461 462 if (!loop) { 463 dbgp_printk("ehci can not be started\n"); 464 return -ENODEV; 465 } 466 dbgp_printk("ehci started\n"); 467 return 0; 468 } 469 470 static int dbgp_ehci_controller_reset(void) 471 { 472 int loop = 250 * 1000; 473 u32 cmd; 474 475 /* Reset the EHCI controller */ 476 cmd = readl(&ehci_regs->command); 477 cmd |= CMD_RESET; 478 writel(cmd, &ehci_regs->command); 479 do { 480 cmd = readl(&ehci_regs->command); 481 } while ((cmd & CMD_RESET) && (--loop > 0)); 482 483 if (!loop) { 484 dbgp_printk("can not reset ehci\n"); 485 return -1; 486 } 487 dbgp_ehci_status("ehci reset done"); 488 return 0; 489 } 490 static int ehci_wait_for_port(int port); 491 /* Return 0 on success 492 * Return -ENODEV for any general failure 493 * Return -EIO if wait for port fails 494 */ 495 static int _dbgp_external_startup(void) 496 { 497 int devnum; 498 struct usb_debug_descriptor dbgp_desc; 499 int ret; 500 u32 ctrl, portsc, cmd; 501 int dbg_port = dbgp_phys_port; 502 int tries = 3; 503 int reset_port_tries = 1; 504 int try_hard_once = 1; 505 506 try_port_reset_again: 507 ret = dbgp_ehci_startup(); 508 if (ret) 509 return ret; 510 511 /* Wait for a device to show up in the debug port */ 512 ret = ehci_wait_for_port(dbg_port); 513 if (ret < 0) { 514 portsc = readl(&ehci_regs->port_status[dbg_port - 1]); 515 if (!(portsc & PORT_CONNECT) && try_hard_once) { 516 /* Last ditch effort to try to force enable 517 * the debug device by using the packet test 518 * ehci command to try and wake it up. */ 519 try_hard_once = 0; 520 cmd = readl(&ehci_regs->command); 521 cmd &= ~CMD_RUN; 522 writel(cmd, &ehci_regs->command); 523 portsc = readl(&ehci_regs->port_status[dbg_port - 1]); 524 portsc |= PORT_TEST_PKT; 525 writel(portsc, &ehci_regs->port_status[dbg_port - 1]); 526 dbgp_ehci_status("Trying to force debug port online"); 527 mdelay(50); 528 dbgp_ehci_controller_reset(); 529 goto try_port_reset_again; 530 } else if (reset_port_tries--) { 531 goto try_port_reset_again; 532 } 533 dbgp_printk("No device found in debug port\n"); 534 return -EIO; 535 } 536 dbgp_ehci_status("wait for port done"); 537 538 /* Enable the debug port */ 539 ctrl = readl(&ehci_debug->control); 540 ctrl |= DBGP_CLAIM; 541 writel(ctrl, &ehci_debug->control); 542 ctrl = readl(&ehci_debug->control); 543 if ((ctrl & DBGP_CLAIM) != DBGP_CLAIM) { 544 dbgp_printk("No device in debug port\n"); 545 writel(ctrl & ~DBGP_CLAIM, &ehci_debug->control); 546 return -ENODEV; 547 } 548 dbgp_ehci_status("debug ported enabled"); 549 550 /* Completely transfer the debug device to the debug controller */ 551 portsc = readl(&ehci_regs->port_status[dbg_port - 1]); 552 portsc &= ~PORT_PE; 553 writel(portsc, &ehci_regs->port_status[dbg_port - 1]); 554 555 dbgp_mdelay(100); 556 557 try_again: 558 /* Find the debug device and make it device number 127 */ 559 for (devnum = 0; devnum <= 127; devnum++) { 560 ret = dbgp_control_msg(devnum, 561 USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE, 562 USB_REQ_GET_DESCRIPTOR, (USB_DT_DEBUG << 8), 0, 563 &dbgp_desc, sizeof(dbgp_desc)); 564 if (ret > 0) 565 break; 566 } 567 if (devnum > 127) { 568 dbgp_printk("Could not find attached debug device\n"); 569 goto err; 570 } 571 dbgp_endpoint_out = dbgp_desc.bDebugOutEndpoint; 572 dbgp_endpoint_in = dbgp_desc.bDebugInEndpoint; 573 574 /* Move the device to 127 if it isn't already there */ 575 if (devnum != USB_DEBUG_DEVNUM) { 576 ret = dbgp_control_msg(devnum, 577 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE, 578 USB_REQ_SET_ADDRESS, USB_DEBUG_DEVNUM, 0, NULL, 0); 579 if (ret < 0) { 580 dbgp_printk("Could not move attached device to %d\n", 581 USB_DEBUG_DEVNUM); 582 goto err; 583 } 584 devnum = USB_DEBUG_DEVNUM; 585 dbgp_printk("debug device renamed to 127\n"); 586 } 587 588 /* Enable the debug interface */ 589 ret = dbgp_control_msg(USB_DEBUG_DEVNUM, 590 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE, 591 USB_REQ_SET_FEATURE, USB_DEVICE_DEBUG_MODE, 0, NULL, 0); 592 if (ret < 0) { 593 dbgp_printk(" Could not enable the debug device\n"); 594 goto err; 595 } 596 dbgp_printk("debug interface enabled\n"); 597 /* Perform a small write to get the even/odd data state in sync 598 */ 599 ret = dbgp_bulk_write(USB_DEBUG_DEVNUM, dbgp_endpoint_out, " ", 1); 600 if (ret < 0) { 601 dbgp_printk("dbgp_bulk_write failed: %d\n", ret); 602 goto err; 603 } 604 dbgp_printk("small write done\n"); 605 dbgp_not_safe = 0; 606 607 return 0; 608 err: 609 if (tries--) 610 goto try_again; 611 return -ENODEV; 612 } 613 614 static int ehci_reset_port(int port) 615 { 616 u32 portsc; 617 u32 delay_time, delay; 618 int loop; 619 620 dbgp_ehci_status("reset port"); 621 /* Reset the usb debug port */ 622 portsc = readl(&ehci_regs->port_status[port - 1]); 623 portsc &= ~PORT_PE; 624 portsc |= PORT_RESET; 625 writel(portsc, &ehci_regs->port_status[port - 1]); 626 627 delay = HUB_ROOT_RESET_TIME; 628 for (delay_time = 0; delay_time < HUB_RESET_TIMEOUT; 629 delay_time += delay) { 630 dbgp_mdelay(delay); 631 portsc = readl(&ehci_regs->port_status[port - 1]); 632 if (!(portsc & PORT_RESET)) 633 break; 634 } 635 if (portsc & PORT_RESET) { 636 /* force reset to complete */ 637 loop = 100 * 1000; 638 writel(portsc & ~(PORT_RWC_BITS | PORT_RESET), 639 &ehci_regs->port_status[port - 1]); 640 do { 641 udelay(1); 642 portsc = readl(&ehci_regs->port_status[port-1]); 643 } while ((portsc & PORT_RESET) && (--loop > 0)); 644 } 645 646 /* Device went away? */ 647 if (!(portsc & PORT_CONNECT)) 648 return -ENOTCONN; 649 650 /* bomb out completely if something weird happened */ 651 if ((portsc & PORT_CSC)) 652 return -EINVAL; 653 654 /* If we've finished resetting, then break out of the loop */ 655 if (!(portsc & PORT_RESET) && (portsc & PORT_PE)) 656 return 0; 657 return -EBUSY; 658 } 659 660 static int ehci_wait_for_port(int port) 661 { 662 u32 status; 663 int ret, reps; 664 665 for (reps = 0; reps < 300; reps++) { 666 status = readl(&ehci_regs->status); 667 if (status & STS_PCD) 668 break; 669 dbgp_mdelay(1); 670 } 671 ret = ehci_reset_port(port); 672 if (ret == 0) 673 return 0; 674 return -ENOTCONN; 675 } 676 677 typedef void (*set_debug_port_t)(int port); 678 679 static void __init default_set_debug_port(int port) 680 { 681 } 682 683 static set_debug_port_t __initdata set_debug_port = default_set_debug_port; 684 685 static void __init nvidia_set_debug_port(int port) 686 { 687 u32 dword; 688 dword = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func, 689 0x74); 690 dword &= ~(0x0f<<12); 691 dword |= ((port & 0x0f)<<12); 692 write_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func, 0x74, 693 dword); 694 dbgp_printk("set debug port to %d\n", port); 695 } 696 697 static void __init detect_set_debug_port(void) 698 { 699 u32 vendorid; 700 701 vendorid = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func, 702 0x00); 703 704 if ((vendorid & 0xffff) == 0x10de) { 705 dbgp_printk("using nvidia set_debug_port\n"); 706 set_debug_port = nvidia_set_debug_port; 707 } 708 } 709 710 /* The code in early_ehci_bios_handoff() is derived from the usb pci 711 * quirk initialization, but altered so as to use the early PCI 712 * routines. */ 713 #define EHCI_USBLEGSUP_BIOS (1 << 16) /* BIOS semaphore */ 714 #define EHCI_USBLEGCTLSTS 4 /* legacy control/status */ 715 static void __init early_ehci_bios_handoff(void) 716 { 717 u32 hcc_params = readl(&ehci_caps->hcc_params); 718 int offset = (hcc_params >> 8) & 0xff; 719 u32 cap; 720 int msec; 721 722 if (!offset) 723 return; 724 725 cap = read_pci_config(ehci_dev.bus, ehci_dev.slot, 726 ehci_dev.func, offset); 727 dbgp_printk("dbgp: ehci BIOS state %08x\n", cap); 728 729 if ((cap & 0xff) == 1 && (cap & EHCI_USBLEGSUP_BIOS)) { 730 dbgp_printk("dbgp: BIOS handoff\n"); 731 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot, 732 ehci_dev.func, offset + 3, 1); 733 } 734 735 /* if boot firmware now owns EHCI, spin till it hands it over. */ 736 msec = 1000; 737 while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) { 738 mdelay(10); 739 msec -= 10; 740 cap = read_pci_config(ehci_dev.bus, ehci_dev.slot, 741 ehci_dev.func, offset); 742 } 743 744 if (cap & EHCI_USBLEGSUP_BIOS) { 745 /* well, possibly buggy BIOS... try to shut it down, 746 * and hope nothing goes too wrong */ 747 dbgp_printk("dbgp: BIOS handoff failed: %08x\n", cap); 748 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot, 749 ehci_dev.func, offset + 2, 0); 750 } 751 752 /* just in case, always disable EHCI SMIs */ 753 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot, ehci_dev.func, 754 offset + EHCI_USBLEGCTLSTS, 0); 755 } 756 757 static int __init ehci_setup(void) 758 { 759 u32 ctrl, portsc, hcs_params; 760 u32 debug_port, new_debug_port = 0, n_ports; 761 int ret, i; 762 int port_map_tried; 763 int playtimes = 3; 764 765 early_ehci_bios_handoff(); 766 767 try_next_time: 768 port_map_tried = 0; 769 770 try_next_port: 771 772 hcs_params = readl(&ehci_caps->hcs_params); 773 debug_port = HCS_DEBUG_PORT(hcs_params); 774 dbgp_phys_port = debug_port; 775 n_ports = HCS_N_PORTS(hcs_params); 776 777 dbgp_printk("debug_port: %d\n", debug_port); 778 dbgp_printk("n_ports: %d\n", n_ports); 779 dbgp_ehci_status(""); 780 781 for (i = 1; i <= n_ports; i++) { 782 portsc = readl(&ehci_regs->port_status[i-1]); 783 dbgp_printk("portstatus%d: %08x\n", i, portsc); 784 } 785 786 if (port_map_tried && (new_debug_port != debug_port)) { 787 if (--playtimes) { 788 set_debug_port(new_debug_port); 789 goto try_next_time; 790 } 791 return -1; 792 } 793 794 /* Only reset the controller if it is not already in the 795 * configured state */ 796 if (!(readl(&ehci_regs->configured_flag) & FLAG_CF)) { 797 if (dbgp_ehci_controller_reset() != 0) 798 return -1; 799 } else { 800 dbgp_ehci_status("ehci skip - already configured"); 801 } 802 803 ret = _dbgp_external_startup(); 804 if (ret == -EIO) 805 goto next_debug_port; 806 807 if (ret < 0) { 808 /* Things didn't work so remove my claim */ 809 ctrl = readl(&ehci_debug->control); 810 ctrl &= ~(DBGP_CLAIM | DBGP_OUT); 811 writel(ctrl, &ehci_debug->control); 812 return -1; 813 } 814 return 0; 815 816 next_debug_port: 817 port_map_tried |= (1<<(debug_port - 1)); 818 new_debug_port = ((debug_port-1+1)%n_ports) + 1; 819 if (port_map_tried != ((1<<n_ports) - 1)) { 820 set_debug_port(new_debug_port); 821 goto try_next_port; 822 } 823 if (--playtimes) { 824 set_debug_port(new_debug_port); 825 goto try_next_time; 826 } 827 828 return -1; 829 } 830 831 int __init early_dbgp_init(char *s) 832 { 833 u32 debug_port, bar, offset; 834 u32 bus, slot, func, cap; 835 void __iomem *ehci_bar; 836 u32 dbgp_num; 837 u32 bar_val; 838 char *e; 839 int ret; 840 u8 byte; 841 842 if (!early_pci_allowed()) 843 return -1; 844 845 dbgp_num = 0; 846 if (*s) 847 dbgp_num = simple_strtoul(s, &e, 10); 848 dbgp_printk("dbgp_num: %d\n", dbgp_num); 849 850 cap = find_dbgp(dbgp_num, &bus, &slot, &func); 851 if (!cap) 852 return -1; 853 854 dbgp_printk("Found EHCI debug port on %02x:%02x.%1x\n", bus, slot, 855 func); 856 857 debug_port = read_pci_config(bus, slot, func, cap); 858 bar = (debug_port >> 29) & 0x7; 859 bar = (bar * 4) + 0xc; 860 offset = (debug_port >> 16) & 0xfff; 861 dbgp_printk("bar: %02x offset: %03x\n", bar, offset); 862 if (bar != PCI_BASE_ADDRESS_0) { 863 dbgp_printk("only debug ports on bar 1 handled.\n"); 864 865 return -1; 866 } 867 868 bar_val = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0); 869 dbgp_printk("bar_val: %02x offset: %03x\n", bar_val, offset); 870 if (bar_val & ~PCI_BASE_ADDRESS_MEM_MASK) { 871 dbgp_printk("only simple 32bit mmio bars supported\n"); 872 873 return -1; 874 } 875 876 /* double check if the mem space is enabled */ 877 byte = read_pci_config_byte(bus, slot, func, 0x04); 878 if (!(byte & 0x2)) { 879 byte |= 0x02; 880 write_pci_config_byte(bus, slot, func, 0x04, byte); 881 dbgp_printk("mmio for ehci enabled\n"); 882 } 883 884 /* 885 * FIXME I don't have the bar size so just guess PAGE_SIZE is more 886 * than enough. 1K is the biggest I have seen. 887 */ 888 set_fixmap_nocache(FIX_DBGP_BASE, bar_val & PAGE_MASK); 889 ehci_bar = (void __iomem *)__fix_to_virt(FIX_DBGP_BASE); 890 ehci_bar += bar_val & ~PAGE_MASK; 891 dbgp_printk("ehci_bar: %p\n", ehci_bar); 892 893 ehci_caps = ehci_bar; 894 ehci_regs = ehci_bar + EARLY_HC_LENGTH(readl(&ehci_caps->hc_capbase)); 895 ehci_debug = ehci_bar + offset; 896 ehci_dev.bus = bus; 897 ehci_dev.slot = slot; 898 ehci_dev.func = func; 899 900 detect_set_debug_port(); 901 902 ret = ehci_setup(); 903 if (ret < 0) { 904 dbgp_printk("ehci_setup failed\n"); 905 ehci_debug = NULL; 906 907 return -1; 908 } 909 dbgp_ehci_status("early_init_complete"); 910 911 return 0; 912 } 913 914 static void early_dbgp_write(struct console *con, const char *str, u32 n) 915 { 916 int chunk, ret; 917 char buf[DBGP_MAX_PACKET]; 918 int use_cr = 0; 919 u32 cmd, ctrl; 920 int reset_run = 0; 921 922 if (!ehci_debug || dbgp_not_safe) 923 return; 924 925 cmd = readl(&ehci_regs->command); 926 if (unlikely(!(cmd & CMD_RUN))) { 927 /* If the ehci controller is not in the run state do extended 928 * checks to see if the acpi or some other initialization also 929 * reset the ehci debug port */ 930 ctrl = readl(&ehci_debug->control); 931 if (!(ctrl & DBGP_ENABLED)) { 932 dbgp_not_safe = 1; 933 _dbgp_external_startup(); 934 } else { 935 cmd |= CMD_RUN; 936 writel(cmd, &ehci_regs->command); 937 reset_run = 1; 938 } 939 } 940 while (n > 0) { 941 for (chunk = 0; chunk < DBGP_MAX_PACKET && n > 0; 942 str++, chunk++, n--) { 943 if (!use_cr && *str == '\n') { 944 use_cr = 1; 945 buf[chunk] = '\r'; 946 str--; 947 n++; 948 continue; 949 } 950 if (use_cr) 951 use_cr = 0; 952 buf[chunk] = *str; 953 } 954 if (chunk > 0) { 955 ret = dbgp_bulk_write(USB_DEBUG_DEVNUM, 956 dbgp_endpoint_out, buf, chunk); 957 } 958 } 959 if (unlikely(reset_run)) { 960 cmd = readl(&ehci_regs->command); 961 cmd &= ~CMD_RUN; 962 writel(cmd, &ehci_regs->command); 963 } 964 } 965 966 struct console early_dbgp_console = { 967 .name = "earlydbg", 968 .write = early_dbgp_write, 969 .flags = CON_PRINTBUFFER, 970 .index = -1, 971 }; 972 973 #if IS_ENABLED(CONFIG_USB) 974 int dbgp_reset_prep(struct usb_hcd *hcd) 975 { 976 int ret = xen_dbgp_reset_prep(hcd); 977 u32 ctrl; 978 979 if (ret) 980 return ret; 981 982 dbgp_not_safe = 1; 983 if (!ehci_debug) 984 return 0; 985 986 if ((early_dbgp_console.index != -1 && 987 !(early_dbgp_console.flags & CON_BOOT)) || 988 dbgp_kgdb_mode) 989 return 1; 990 /* This means the console is not initialized, or should get 991 * shutdown so as to allow for reuse of the usb device, which 992 * means it is time to shutdown the usb debug port. */ 993 ctrl = readl(&ehci_debug->control); 994 if (ctrl & DBGP_ENABLED) { 995 ctrl &= ~(DBGP_CLAIM); 996 writel(ctrl, &ehci_debug->control); 997 } 998 return 0; 999 } 1000 EXPORT_SYMBOL_GPL(dbgp_reset_prep); 1001 1002 int dbgp_external_startup(struct usb_hcd *hcd) 1003 { 1004 return xen_dbgp_external_startup(hcd) ?: _dbgp_external_startup(); 1005 } 1006 EXPORT_SYMBOL_GPL(dbgp_external_startup); 1007 #endif /* USB */ 1008 1009 #ifdef CONFIG_KGDB 1010 1011 static char kgdbdbgp_buf[DBGP_MAX_PACKET]; 1012 static int kgdbdbgp_buf_sz; 1013 static int kgdbdbgp_buf_idx; 1014 static int kgdbdbgp_loop_cnt = DBGP_LOOPS; 1015 1016 static int kgdbdbgp_read_char(void) 1017 { 1018 int ret; 1019 1020 if (kgdbdbgp_buf_idx < kgdbdbgp_buf_sz) { 1021 char ch = kgdbdbgp_buf[kgdbdbgp_buf_idx++]; 1022 return ch; 1023 } 1024 1025 ret = dbgp_bulk_read(USB_DEBUG_DEVNUM, dbgp_endpoint_in, 1026 &kgdbdbgp_buf, DBGP_MAX_PACKET, 1027 kgdbdbgp_loop_cnt); 1028 if (ret <= 0) 1029 return NO_POLL_CHAR; 1030 kgdbdbgp_buf_sz = ret; 1031 kgdbdbgp_buf_idx = 1; 1032 return kgdbdbgp_buf[0]; 1033 } 1034 1035 static void kgdbdbgp_write_char(u8 chr) 1036 { 1037 early_dbgp_write(NULL, &chr, 1); 1038 } 1039 1040 static struct kgdb_io kgdbdbgp_io_ops = { 1041 .name = "kgdbdbgp", 1042 .read_char = kgdbdbgp_read_char, 1043 .write_char = kgdbdbgp_write_char, 1044 }; 1045 1046 static int kgdbdbgp_wait_time; 1047 1048 static int __init kgdbdbgp_parse_config(char *str) 1049 { 1050 char *ptr; 1051 1052 if (!ehci_debug) { 1053 if (early_dbgp_init(str)) 1054 return -1; 1055 } 1056 ptr = strchr(str, ','); 1057 if (ptr) { 1058 ptr++; 1059 kgdbdbgp_wait_time = simple_strtoul(ptr, &ptr, 10); 1060 } 1061 kgdb_register_io_module(&kgdbdbgp_io_ops); 1062 kgdbdbgp_io_ops.is_console = early_dbgp_console.index != -1; 1063 1064 return 0; 1065 } 1066 early_param("kgdbdbgp", kgdbdbgp_parse_config); 1067 1068 static int kgdbdbgp_reader_thread(void *ptr) 1069 { 1070 int ret; 1071 1072 while (readl(&ehci_debug->control) & DBGP_ENABLED) { 1073 kgdbdbgp_loop_cnt = 1; 1074 ret = kgdbdbgp_read_char(); 1075 kgdbdbgp_loop_cnt = DBGP_LOOPS; 1076 if (ret != NO_POLL_CHAR) { 1077 if (ret == 0x3 || ret == '$') { 1078 if (ret == '$') 1079 kgdbdbgp_buf_idx--; 1080 kgdb_breakpoint(); 1081 } 1082 continue; 1083 } 1084 schedule_timeout_interruptible(kgdbdbgp_wait_time * HZ); 1085 } 1086 return 0; 1087 } 1088 1089 static int __init kgdbdbgp_start_thread(void) 1090 { 1091 if (dbgp_kgdb_mode && kgdbdbgp_wait_time) 1092 kthread_run(kgdbdbgp_reader_thread, NULL, "%s", "dbgp"); 1093 1094 return 0; 1095 } 1096 module_init(kgdbdbgp_start_thread); 1097 #endif /* CONFIG_KGDB */ 1098