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