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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Standalone EHCI usb debug driver
4 *
5 * Originally written by:
6 * Eric W. Biederman" <ebiederm@xmission.com> and
7 * Yinghai Lu <yhlu.kernel@gmail.com>
8 *
9 * Changes for early/late printk and HW errata:
10 * Jason Wessel <jason.wessel@windriver.com>
11 * Copyright (C) 2009 Wind River Systems, Inc.
12 *
13 */
14
15#include <linux/console.h>
16#include <linux/errno.h>
17#include <linux/init.h>
18#include <linux/iopoll.h>
19#include <linux/pci_regs.h>
20#include <linux/pci_ids.h>
21#include <linux/usb/ch9.h>
22#include <linux/usb/ehci_def.h>
23#include <linux/delay.h>
24#include <linux/serial_core.h>
25#include <linux/kgdb.h>
26#include <linux/kthread.h>
27#include <asm/io.h>
28#include <asm/pci-direct.h>
29#include <asm/fixmap.h>
30
31/* The code here is intended to talk directly to the EHCI debug port
32 * and does not require that you have any kind of USB host controller
33 * drivers or USB device drivers compiled into the kernel.
34 *
35 * If you make a change to anything in here, the following test cases
36 * need to pass where a USB debug device works in the following
37 * configurations.
38 *
39 * 1. boot args: earlyprintk=dbgp
40 * o kernel compiled with # CONFIG_USB_EHCI_HCD is not set
41 * o kernel compiled with CONFIG_USB_EHCI_HCD=y
42 * 2. boot args: earlyprintk=dbgp,keep
43 * o kernel compiled with # CONFIG_USB_EHCI_HCD is not set
44 * o kernel compiled with CONFIG_USB_EHCI_HCD=y
45 * 3. boot args: earlyprintk=dbgp console=ttyUSB0
46 * o kernel has CONFIG_USB_EHCI_HCD=y and
47 * CONFIG_USB_SERIAL_DEBUG=y
48 * 4. boot args: earlyprintk=vga,dbgp
49 * o kernel compiled with # CONFIG_USB_EHCI_HCD is not set
50 * o kernel compiled with CONFIG_USB_EHCI_HCD=y
51 *
52 * For the 4th configuration you can turn on or off the DBGP_DEBUG
53 * such that you can debug the dbgp device's driver code.
54 */
55
56static int dbgp_phys_port = 1;
57
58static struct ehci_caps __iomem *ehci_caps;
59static struct ehci_regs __iomem *ehci_regs;
60static struct ehci_dbg_port __iomem *ehci_debug;
61static int dbgp_not_safe; /* Cannot use debug device during ehci reset */
62static unsigned int dbgp_endpoint_out;
63static unsigned int dbgp_endpoint_in;
64
65struct ehci_dev {
66 u32 bus;
67 u32 slot;
68 u32 func;
69};
70
71static struct ehci_dev ehci_dev;
72
73#define USB_DEBUG_DEVNUM 127
74
75#ifdef DBGP_DEBUG
76#define dbgp_printk printk
77static void dbgp_ehci_status(char *str)
78{
79 if (!ehci_debug)
80 return;
81 dbgp_printk("dbgp: %s\n", str);
82 dbgp_printk(" Debug control: %08x", readl(&ehci_debug->control));
83 dbgp_printk(" ehci cmd : %08x", readl(&ehci_regs->command));
84 dbgp_printk(" ehci conf flg: %08x\n",
85 readl(&ehci_regs->configured_flag));
86 dbgp_printk(" ehci status : %08x", readl(&ehci_regs->status));
87 dbgp_printk(" ehci portsc : %08x\n",
88 readl(&ehci_regs->port_status[dbgp_phys_port - 1]));
89}
90#else
91static inline void dbgp_ehci_status(char *str) { }
92static inline void dbgp_printk(const char *fmt, ...) { }
93#endif
94
95static inline u32 dbgp_len_update(u32 x, u32 len)
96{
97 return (x & ~0x0f) | (len & 0x0f);
98}
99
100#ifdef CONFIG_KGDB
101static struct kgdb_io kgdbdbgp_io_ops;
102#define dbgp_kgdb_mode (dbg_io_ops == &kgdbdbgp_io_ops)
103#else
104#define dbgp_kgdb_mode (0)
105#endif
106
107/* Local version of HC_LENGTH macro as ehci struct is not available here */
108#define EARLY_HC_LENGTH(p) (0x00ff & (p)) /* bits 7 : 0 */
109
110/*
111 * USB Packet IDs (PIDs)
112 */
113
114/* token */
115#define USB_PID_OUT 0xe1
116#define USB_PID_IN 0x69
117#define USB_PID_SOF 0xa5
118#define USB_PID_SETUP 0x2d
119/* handshake */
120#define USB_PID_ACK 0xd2
121#define USB_PID_NAK 0x5a
122#define USB_PID_STALL 0x1e
123#define USB_PID_NYET 0x96
124/* data */
125#define USB_PID_DATA0 0xc3
126#define USB_PID_DATA1 0x4b
127#define USB_PID_DATA2 0x87
128#define USB_PID_MDATA 0x0f
129/* Special */
130#define USB_PID_PREAMBLE 0x3c
131#define USB_PID_ERR 0x3c
132#define USB_PID_SPLIT 0x78
133#define USB_PID_PING 0xb4
134#define USB_PID_UNDEF_0 0xf0
135
136#define USB_PID_DATA_TOGGLE 0x88
137#define DBGP_CLAIM (DBGP_OWNER | DBGP_ENABLED | DBGP_INUSE)
138
139#define PCI_CAP_ID_EHCI_DEBUG 0xa
140
141#define HUB_ROOT_RESET_TIME 50 /* times are in msec */
142#define HUB_SHORT_RESET_TIME 10
143#define HUB_LONG_RESET_TIME 200
144#define HUB_RESET_TIMEOUT 500
145
146#define DBGP_MAX_PACKET 8
147#define DBGP_TIMEOUT (250 * 1000)
148#define DBGP_LOOPS 1000
149
150static inline u32 dbgp_pid_write_update(u32 x, u32 tok)
151{
152 static int data0 = USB_PID_DATA1;
153 data0 ^= USB_PID_DATA_TOGGLE;
154 return (x & 0xffff0000) | (data0 << 8) | (tok & 0xff);
155}
156
157static inline u32 dbgp_pid_read_update(u32 x, u32 tok)
158{
159 return (x & 0xffff0000) | (USB_PID_DATA0 << 8) | (tok & 0xff);
160}
161
162static int dbgp_wait_until_complete(void)
163{
164 u32 ctrl;
165 int ret;
166
167 ret = readl_poll_timeout_atomic(&ehci_debug->control, ctrl,
168 (ctrl & DBGP_DONE), 1, DBGP_TIMEOUT);
169 if (ret)
170 return -DBGP_TIMEOUT;
171
172 /*
173 * Now that we have observed the completed transaction,
174 * clear the done bit.
175 */
176 writel(ctrl | DBGP_DONE, &ehci_debug->control);
177 return (ctrl & DBGP_ERROR) ? -DBGP_ERRCODE(ctrl) : DBGP_LEN(ctrl);
178}
179
180static inline void dbgp_mdelay(int ms)
181{
182 int i;
183
184 while (ms--) {
185 for (i = 0; i < 1000; i++)
186 outb(0x1, 0x80);
187 }
188}
189
190static void dbgp_breath(void)
191{
192 /* Sleep to give the debug port a chance to breathe */
193}
194
195static int dbgp_wait_until_done(unsigned ctrl, int loop)
196{
197 u32 pids, lpid;
198 int ret;
199
200retry:
201 writel(ctrl | DBGP_GO, &ehci_debug->control);
202 ret = dbgp_wait_until_complete();
203 pids = readl(&ehci_debug->pids);
204 lpid = DBGP_PID_GET(pids);
205
206 if (ret < 0) {
207 /* A -DBGP_TIMEOUT failure here means the device has
208 * failed, perhaps because it was unplugged, in which
209 * case we do not want to hang the system so the dbgp
210 * will be marked as unsafe to use. EHCI reset is the
211 * only way to recover if you unplug the dbgp device.
212 */
213 if (ret == -DBGP_TIMEOUT && !dbgp_not_safe)
214 dbgp_not_safe = 1;
215 if (ret == -DBGP_ERR_BAD && --loop > 0)
216 goto retry;
217 return ret;
218 }
219
220 /*
221 * If the port is getting full or it has dropped data
222 * start pacing ourselves, not necessary but it's friendly.
223 */
224 if ((lpid == USB_PID_NAK) || (lpid == USB_PID_NYET))
225 dbgp_breath();
226
227 /* If I get a NACK reissue the transmission */
228 if (lpid == USB_PID_NAK) {
229 if (--loop > 0)
230 goto retry;
231 }
232
233 return ret;
234}
235
236static inline void dbgp_set_data(const void *buf, int size)
237{
238 const unsigned char *bytes = buf;
239 u32 lo, hi;
240 int i;
241
242 lo = hi = 0;
243 for (i = 0; i < 4 && i < size; i++)
244 lo |= bytes[i] << (8*i);
245 for (; i < 8 && i < size; i++)
246 hi |= bytes[i] << (8*(i - 4));
247 writel(lo, &ehci_debug->data03);
248 writel(hi, &ehci_debug->data47);
249}
250
251static inline void dbgp_get_data(void *buf, int size)
252{
253 unsigned char *bytes = buf;
254 u32 lo, hi;
255 int i;
256
257 lo = readl(&ehci_debug->data03);
258 hi = readl(&ehci_debug->data47);
259 for (i = 0; i < 4 && i < size; i++)
260 bytes[i] = (lo >> (8*i)) & 0xff;
261 for (; i < 8 && i < size; i++)
262 bytes[i] = (hi >> (8*(i - 4))) & 0xff;
263}
264
265static int dbgp_bulk_write(unsigned devnum, unsigned endpoint,
266 const char *bytes, int size)
267{
268 int ret;
269 u32 addr;
270 u32 pids, ctrl;
271
272 if (size > DBGP_MAX_PACKET)
273 return -1;
274
275 addr = DBGP_EPADDR(devnum, endpoint);
276
277 pids = readl(&ehci_debug->pids);
278 pids = dbgp_pid_write_update(pids, USB_PID_OUT);
279
280 ctrl = readl(&ehci_debug->control);
281 ctrl = dbgp_len_update(ctrl, size);
282 ctrl |= DBGP_OUT;
283 ctrl |= DBGP_GO;
284
285 dbgp_set_data(bytes, size);
286 writel(addr, &ehci_debug->address);
287 writel(pids, &ehci_debug->pids);
288 ret = dbgp_wait_until_done(ctrl, DBGP_LOOPS);
289
290 return ret;
291}
292
293static int dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data,
294 int size, int loops)
295{
296 u32 pids, addr, ctrl;
297 int ret;
298
299 if (size > DBGP_MAX_PACKET)
300 return -1;
301
302 addr = DBGP_EPADDR(devnum, endpoint);
303
304 pids = readl(&ehci_debug->pids);
305 pids = dbgp_pid_read_update(pids, USB_PID_IN);
306
307 ctrl = readl(&ehci_debug->control);
308 ctrl = dbgp_len_update(ctrl, size);
309 ctrl &= ~DBGP_OUT;
310 ctrl |= DBGP_GO;
311
312 writel(addr, &ehci_debug->address);
313 writel(pids, &ehci_debug->pids);
314 ret = dbgp_wait_until_done(ctrl, loops);
315 if (ret < 0)
316 return ret;
317
318 if (size > ret)
319 size = ret;
320 dbgp_get_data(data, size);
321 return ret;
322}
323
324static int dbgp_control_msg(unsigned devnum, int requesttype,
325 int request, int value, int index, void *data, int size)
326{
327 u32 pids, addr, ctrl;
328 struct usb_ctrlrequest req;
329 int read;
330 int ret;
331
332 read = (requesttype & USB_DIR_IN) != 0;
333 if (size > (read ? DBGP_MAX_PACKET : 0))
334 return -1;
335
336 /* Compute the control message */
337 req.bRequestType = requesttype;
338 req.bRequest = request;
339 req.wValue = cpu_to_le16(value);
340 req.wIndex = cpu_to_le16(index);
341 req.wLength = cpu_to_le16(size);
342
343 pids = DBGP_PID_SET(USB_PID_DATA0, USB_PID_SETUP);
344 addr = DBGP_EPADDR(devnum, 0);
345
346 ctrl = readl(&ehci_debug->control);
347 ctrl = dbgp_len_update(ctrl, sizeof(req));
348 ctrl |= DBGP_OUT;
349 ctrl |= DBGP_GO;
350
351 /* Send the setup message */
352 dbgp_set_data(&req, sizeof(req));
353 writel(addr, &ehci_debug->address);
354 writel(pids, &ehci_debug->pids);
355 ret = dbgp_wait_until_done(ctrl, DBGP_LOOPS);
356 if (ret < 0)
357 return ret;
358
359 /* Read the result */
360 return dbgp_bulk_read(devnum, 0, data, size, DBGP_LOOPS);
361}
362
363/* Find a PCI capability */
364static u32 __init find_cap(u32 num, u32 slot, u32 func, int cap)
365{
366 u8 pos;
367 int bytes;
368
369 if (!(read_pci_config_16(num, slot, func, PCI_STATUS) &
370 PCI_STATUS_CAP_LIST))
371 return 0;
372
373 pos = read_pci_config_byte(num, slot, func, PCI_CAPABILITY_LIST);
374 for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
375 u8 id;
376
377 pos &= ~3;
378 id = read_pci_config_byte(num, slot, func, pos+PCI_CAP_LIST_ID);
379 if (id == 0xff)
380 break;
381 if (id == cap)
382 return pos;
383
384 pos = read_pci_config_byte(num, slot, func,
385 pos+PCI_CAP_LIST_NEXT);
386 }
387 return 0;
388}
389
390static u32 __init __find_dbgp(u32 bus, u32 slot, u32 func)
391{
392 u32 class;
393
394 class = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
395 if ((class >> 8) != PCI_CLASS_SERIAL_USB_EHCI)
396 return 0;
397
398 return find_cap(bus, slot, func, PCI_CAP_ID_EHCI_DEBUG);
399}
400
401static u32 __init find_dbgp(int ehci_num, u32 *rbus, u32 *rslot, u32 *rfunc)
402{
403 u32 bus, slot, func;
404
405 for (bus = 0; bus < 256; bus++) {
406 for (slot = 0; slot < 32; slot++) {
407 for (func = 0; func < 8; func++) {
408 unsigned cap;
409
410 cap = __find_dbgp(bus, slot, func);
411
412 if (!cap)
413 continue;
414 if (ehci_num-- != 0)
415 continue;
416 *rbus = bus;
417 *rslot = slot;
418 *rfunc = func;
419 return cap;
420 }
421 }
422 }
423 return 0;
424}
425
426static int dbgp_ehci_startup(void)
427{
428 u32 ctrl, cmd, status;
429 int loop;
430
431 /* Claim ownership, but do not enable yet */
432 ctrl = readl(&ehci_debug->control);
433 ctrl |= DBGP_OWNER;
434 ctrl &= ~(DBGP_ENABLED | DBGP_INUSE);
435 writel(ctrl, &ehci_debug->control);
436 udelay(1);
437
438 dbgp_ehci_status("EHCI startup");
439 /* Start the ehci running */
440 cmd = readl(&ehci_regs->command);
441 cmd &= ~(CMD_LRESET | CMD_IAAD | CMD_PSE | CMD_ASE | CMD_RESET);
442 cmd |= CMD_RUN;
443 writel(cmd, &ehci_regs->command);
444
445 /* Ensure everything is routed to the EHCI */
446 writel(FLAG_CF, &ehci_regs->configured_flag);
447
448 /* Wait until the controller is no longer halted */
449 loop = 1000;
450 do {
451 status = readl(&ehci_regs->status);
452 if (!(status & STS_HALT))
453 break;
454 udelay(1);
455 } while (--loop > 0);
456
457 if (!loop) {
458 dbgp_printk("ehci can not be started\n");
459 return -ENODEV;
460 }
461 dbgp_printk("ehci started\n");
462 return 0;
463}
464
465static int dbgp_ehci_controller_reset(void)
466{
467 int loop = 250 * 1000;
468 u32 cmd;
469
470 /* Reset the EHCI controller */
471 cmd = readl(&ehci_regs->command);
472 cmd |= CMD_RESET;
473 writel(cmd, &ehci_regs->command);
474 do {
475 cmd = readl(&ehci_regs->command);
476 } while ((cmd & CMD_RESET) && (--loop > 0));
477
478 if (!loop) {
479 dbgp_printk("can not reset ehci\n");
480 return -1;
481 }
482 dbgp_ehci_status("ehci reset done");
483 return 0;
484}
485static int ehci_wait_for_port(int port);
486/* Return 0 on success
487 * Return -ENODEV for any general failure
488 * Return -EIO if wait for port fails
489 */
490static int _dbgp_external_startup(void)
491{
492 int devnum;
493 struct usb_debug_descriptor dbgp_desc;
494 int ret;
495 u32 ctrl, portsc, cmd;
496 int dbg_port = dbgp_phys_port;
497 int tries = 3;
498 int reset_port_tries = 1;
499 int try_hard_once = 1;
500
501try_port_reset_again:
502 ret = dbgp_ehci_startup();
503 if (ret)
504 return ret;
505
506 /* Wait for a device to show up in the debug port */
507 ret = ehci_wait_for_port(dbg_port);
508 if (ret < 0) {
509 portsc = readl(&ehci_regs->port_status[dbg_port - 1]);
510 if (!(portsc & PORT_CONNECT) && try_hard_once) {
511 /* Last ditch effort to try to force enable
512 * the debug device by using the packet test
513 * ehci command to try and wake it up. */
514 try_hard_once = 0;
515 cmd = readl(&ehci_regs->command);
516 cmd &= ~CMD_RUN;
517 writel(cmd, &ehci_regs->command);
518 portsc = readl(&ehci_regs->port_status[dbg_port - 1]);
519 portsc |= PORT_TEST_PKT;
520 writel(portsc, &ehci_regs->port_status[dbg_port - 1]);
521 dbgp_ehci_status("Trying to force debug port online");
522 mdelay(50);
523 dbgp_ehci_controller_reset();
524 goto try_port_reset_again;
525 } else if (reset_port_tries--) {
526 goto try_port_reset_again;
527 }
528 dbgp_printk("No device found in debug port\n");
529 return -EIO;
530 }
531 dbgp_ehci_status("wait for port done");
532
533 /* Enable the debug port */
534 ctrl = readl(&ehci_debug->control);
535 ctrl |= DBGP_CLAIM;
536 writel(ctrl, &ehci_debug->control);
537 ctrl = readl(&ehci_debug->control);
538 if ((ctrl & DBGP_CLAIM) != DBGP_CLAIM) {
539 dbgp_printk("No device in debug port\n");
540 writel(ctrl & ~DBGP_CLAIM, &ehci_debug->control);
541 return -ENODEV;
542 }
543 dbgp_ehci_status("debug ported enabled");
544
545 /* Completely transfer the debug device to the debug controller */
546 portsc = readl(&ehci_regs->port_status[dbg_port - 1]);
547 portsc &= ~PORT_PE;
548 writel(portsc, &ehci_regs->port_status[dbg_port - 1]);
549
550 dbgp_mdelay(100);
551
552try_again:
553 /* Find the debug device and make it device number 127 */
554 for (devnum = 0; devnum <= 127; devnum++) {
555 ret = dbgp_control_msg(devnum,
556 USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
557 USB_REQ_GET_DESCRIPTOR, (USB_DT_DEBUG << 8), 0,
558 &dbgp_desc, sizeof(dbgp_desc));
559 if (ret > 0)
560 break;
561 }
562 if (devnum > 127) {
563 dbgp_printk("Could not find attached debug device\n");
564 goto err;
565 }
566 dbgp_endpoint_out = dbgp_desc.bDebugOutEndpoint;
567 dbgp_endpoint_in = dbgp_desc.bDebugInEndpoint;
568
569 /* Move the device to 127 if it isn't already there */
570 if (devnum != USB_DEBUG_DEVNUM) {
571 ret = dbgp_control_msg(devnum,
572 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
573 USB_REQ_SET_ADDRESS, USB_DEBUG_DEVNUM, 0, NULL, 0);
574 if (ret < 0) {
575 dbgp_printk("Could not move attached device to %d\n",
576 USB_DEBUG_DEVNUM);
577 goto err;
578 }
579 dbgp_printk("debug device renamed to 127\n");
580 }
581
582 /* Enable the debug interface */
583 ret = dbgp_control_msg(USB_DEBUG_DEVNUM,
584 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
585 USB_REQ_SET_FEATURE, USB_DEVICE_DEBUG_MODE, 0, NULL, 0);
586 if (ret < 0) {
587 dbgp_printk(" Could not enable the debug device\n");
588 goto err;
589 }
590 dbgp_printk("debug interface enabled\n");
591 /* Perform a small write to get the even/odd data state in sync
592 */
593 ret = dbgp_bulk_write(USB_DEBUG_DEVNUM, dbgp_endpoint_out, " ", 1);
594 if (ret < 0) {
595 dbgp_printk("dbgp_bulk_write failed: %d\n", ret);
596 goto err;
597 }
598 dbgp_printk("small write done\n");
599 dbgp_not_safe = 0;
600
601 return 0;
602err:
603 if (tries--)
604 goto try_again;
605 return -ENODEV;
606}
607
608static int ehci_reset_port(int port)
609{
610 u32 portsc;
611 u32 delay_time, delay;
612 int loop;
613
614 dbgp_ehci_status("reset port");
615 /* Reset the usb debug port */
616 portsc = readl(&ehci_regs->port_status[port - 1]);
617 portsc &= ~PORT_PE;
618 portsc |= PORT_RESET;
619 writel(portsc, &ehci_regs->port_status[port - 1]);
620
621 delay = HUB_ROOT_RESET_TIME;
622 for (delay_time = 0; delay_time < HUB_RESET_TIMEOUT;
623 delay_time += delay) {
624 dbgp_mdelay(delay);
625 portsc = readl(&ehci_regs->port_status[port - 1]);
626 if (!(portsc & PORT_RESET))
627 break;
628 }
629 if (portsc & PORT_RESET) {
630 /* force reset to complete */
631 loop = 100 * 1000;
632 writel(portsc & ~(PORT_RWC_BITS | PORT_RESET),
633 &ehci_regs->port_status[port - 1]);
634 do {
635 udelay(1);
636 portsc = readl(&ehci_regs->port_status[port-1]);
637 } while ((portsc & PORT_RESET) && (--loop > 0));
638 }
639
640 /* Device went away? */
641 if (!(portsc & PORT_CONNECT))
642 return -ENOTCONN;
643
644 /* bomb out completely if something weird happened */
645 if ((portsc & PORT_CSC))
646 return -EINVAL;
647
648 /* If we've finished resetting, then break out of the loop */
649 if (!(portsc & PORT_RESET) && (portsc & PORT_PE))
650 return 0;
651 return -EBUSY;
652}
653
654static int ehci_wait_for_port(int port)
655{
656 u32 status;
657 int ret, reps;
658
659 for (reps = 0; reps < 300; reps++) {
660 status = readl(&ehci_regs->status);
661 if (status & STS_PCD)
662 break;
663 dbgp_mdelay(1);
664 }
665 ret = ehci_reset_port(port);
666 if (ret == 0)
667 return 0;
668 return -ENOTCONN;
669}
670
671typedef void (*set_debug_port_t)(int port);
672
673static void __init default_set_debug_port(int port)
674{
675}
676
677static set_debug_port_t __initdata set_debug_port = default_set_debug_port;
678
679static void __init nvidia_set_debug_port(int port)
680{
681 u32 dword;
682 dword = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
683 0x74);
684 dword &= ~(0x0f<<12);
685 dword |= ((port & 0x0f)<<12);
686 write_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func, 0x74,
687 dword);
688 dbgp_printk("set debug port to %d\n", port);
689}
690
691static void __init detect_set_debug_port(void)
692{
693 u32 vendorid;
694
695 vendorid = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
696 0x00);
697
698 if ((vendorid & 0xffff) == 0x10de) {
699 dbgp_printk("using nvidia set_debug_port\n");
700 set_debug_port = nvidia_set_debug_port;
701 }
702}
703
704/* The code in early_ehci_bios_handoff() is derived from the usb pci
705 * quirk initialization, but altered so as to use the early PCI
706 * routines. */
707#define EHCI_USBLEGSUP_BIOS (1 << 16) /* BIOS semaphore */
708#define EHCI_USBLEGCTLSTS 4 /* legacy control/status */
709static void __init early_ehci_bios_handoff(void)
710{
711 u32 hcc_params = readl(&ehci_caps->hcc_params);
712 int offset = (hcc_params >> 8) & 0xff;
713 u32 cap;
714 int msec;
715
716 if (!offset)
717 return;
718
719 cap = read_pci_config(ehci_dev.bus, ehci_dev.slot,
720 ehci_dev.func, offset);
721 dbgp_printk("dbgp: ehci BIOS state %08x\n", cap);
722
723 if ((cap & 0xff) == 1 && (cap & EHCI_USBLEGSUP_BIOS)) {
724 dbgp_printk("dbgp: BIOS handoff\n");
725 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot,
726 ehci_dev.func, offset + 3, 1);
727 }
728
729 /* if boot firmware now owns EHCI, spin till it hands it over. */
730 msec = 1000;
731 while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
732 mdelay(10);
733 msec -= 10;
734 cap = read_pci_config(ehci_dev.bus, ehci_dev.slot,
735 ehci_dev.func, offset);
736 }
737
738 if (cap & EHCI_USBLEGSUP_BIOS) {
739 /* well, possibly buggy BIOS... try to shut it down,
740 * and hope nothing goes too wrong */
741 dbgp_printk("dbgp: BIOS handoff failed: %08x\n", cap);
742 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot,
743 ehci_dev.func, offset + 2, 0);
744 }
745
746 /* just in case, always disable EHCI SMIs */
747 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
748 offset + EHCI_USBLEGCTLSTS, 0);
749}
750
751static int __init ehci_setup(void)
752{
753 u32 ctrl, portsc, hcs_params;
754 u32 debug_port, new_debug_port = 0, n_ports;
755 int ret, i;
756 int port_map_tried;
757 int playtimes = 3;
758
759 early_ehci_bios_handoff();
760
761try_next_time:
762 port_map_tried = 0;
763
764try_next_port:
765
766 hcs_params = readl(&ehci_caps->hcs_params);
767 debug_port = HCS_DEBUG_PORT(hcs_params);
768 dbgp_phys_port = debug_port;
769 n_ports = HCS_N_PORTS(hcs_params);
770
771 dbgp_printk("debug_port: %d\n", debug_port);
772 dbgp_printk("n_ports: %d\n", n_ports);
773 dbgp_ehci_status("");
774
775 for (i = 1; i <= n_ports; i++) {
776 portsc = readl(&ehci_regs->port_status[i-1]);
777 dbgp_printk("portstatus%d: %08x\n", i, portsc);
778 }
779
780 if (port_map_tried && (new_debug_port != debug_port)) {
781 if (--playtimes) {
782 set_debug_port(new_debug_port);
783 goto try_next_time;
784 }
785 return -1;
786 }
787
788 /* Only reset the controller if it is not already in the
789 * configured state */
790 if (!(readl(&ehci_regs->configured_flag) & FLAG_CF)) {
791 if (dbgp_ehci_controller_reset() != 0)
792 return -1;
793 } else {
794 dbgp_ehci_status("ehci skip - already configured");
795 }
796
797 ret = _dbgp_external_startup();
798 if (ret == -EIO)
799 goto next_debug_port;
800
801 if (ret < 0) {
802 /* Things didn't work so remove my claim */
803 ctrl = readl(&ehci_debug->control);
804 ctrl &= ~(DBGP_CLAIM | DBGP_OUT);
805 writel(ctrl, &ehci_debug->control);
806 return -1;
807 }
808 return 0;
809
810next_debug_port:
811 port_map_tried |= (1<<(debug_port - 1));
812 new_debug_port = ((debug_port-1+1)%n_ports) + 1;
813 if (port_map_tried != ((1<<n_ports) - 1)) {
814 set_debug_port(new_debug_port);
815 goto try_next_port;
816 }
817 if (--playtimes) {
818 set_debug_port(new_debug_port);
819 goto try_next_time;
820 }
821
822 return -1;
823}
824
825int __init early_dbgp_init(char *s)
826{
827 u32 debug_port, bar, offset;
828 u32 bus, slot, func, cap;
829 void __iomem *ehci_bar;
830 u32 dbgp_num;
831 u32 bar_val;
832 char *e;
833 int ret;
834 u8 byte;
835
836 if (!early_pci_allowed())
837 return -1;
838
839 dbgp_num = 0;
840 if (*s)
841 dbgp_num = simple_strtoul(s, &e, 10);
842 dbgp_printk("dbgp_num: %d\n", dbgp_num);
843
844 cap = find_dbgp(dbgp_num, &bus, &slot, &func);
845 if (!cap)
846 return -1;
847
848 dbgp_printk("Found EHCI debug port on %02x:%02x.%1x\n", bus, slot,
849 func);
850
851 debug_port = read_pci_config(bus, slot, func, cap);
852 bar = (debug_port >> 29) & 0x7;
853 bar = (bar * 4) + 0xc;
854 offset = (debug_port >> 16) & 0xfff;
855 dbgp_printk("bar: %02x offset: %03x\n", bar, offset);
856 if (bar != PCI_BASE_ADDRESS_0) {
857 dbgp_printk("only debug ports on bar 1 handled.\n");
858
859 return -1;
860 }
861
862 bar_val = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
863 dbgp_printk("bar_val: %02x offset: %03x\n", bar_val, offset);
864 if (bar_val & ~PCI_BASE_ADDRESS_MEM_MASK) {
865 dbgp_printk("only simple 32bit mmio bars supported\n");
866
867 return -1;
868 }
869
870 /* double check if the mem space is enabled */
871 byte = read_pci_config_byte(bus, slot, func, 0x04);
872 if (!(byte & 0x2)) {
873 byte |= 0x02;
874 write_pci_config_byte(bus, slot, func, 0x04, byte);
875 dbgp_printk("mmio for ehci enabled\n");
876 }
877
878 /*
879 * FIXME I don't have the bar size so just guess PAGE_SIZE is more
880 * than enough. 1K is the biggest I have seen.
881 */
882 set_fixmap_nocache(FIX_DBGP_BASE, bar_val & PAGE_MASK);
883 ehci_bar = (void __iomem *)__fix_to_virt(FIX_DBGP_BASE);
884 ehci_bar += bar_val & ~PAGE_MASK;
885 dbgp_printk("ehci_bar: %p\n", ehci_bar);
886
887 ehci_caps = ehci_bar;
888 ehci_regs = ehci_bar + EARLY_HC_LENGTH(readl(&ehci_caps->hc_capbase));
889 ehci_debug = ehci_bar + offset;
890 ehci_dev.bus = bus;
891 ehci_dev.slot = slot;
892 ehci_dev.func = func;
893
894 detect_set_debug_port();
895
896 ret = ehci_setup();
897 if (ret < 0) {
898 dbgp_printk("ehci_setup failed\n");
899 ehci_debug = NULL;
900
901 return -1;
902 }
903 dbgp_ehci_status("early_init_complete");
904
905 return 0;
906}
907
908static void early_dbgp_write(struct console *con, const char *str, u32 n)
909{
910 int chunk;
911 char buf[DBGP_MAX_PACKET];
912 int use_cr = 0;
913 u32 cmd, ctrl;
914 int reset_run = 0;
915
916 if (!ehci_debug || dbgp_not_safe)
917 return;
918
919 cmd = readl(&ehci_regs->command);
920 if (unlikely(!(cmd & CMD_RUN))) {
921 /* If the ehci controller is not in the run state do extended
922 * checks to see if the acpi or some other initialization also
923 * reset the ehci debug port */
924 ctrl = readl(&ehci_debug->control);
925 if (!(ctrl & DBGP_ENABLED)) {
926 dbgp_not_safe = 1;
927 _dbgp_external_startup();
928 } else {
929 cmd |= CMD_RUN;
930 writel(cmd, &ehci_regs->command);
931 reset_run = 1;
932 }
933 }
934 while (n > 0) {
935 for (chunk = 0; chunk < DBGP_MAX_PACKET && n > 0;
936 str++, chunk++, n--) {
937 if (!use_cr && *str == '\n') {
938 use_cr = 1;
939 buf[chunk] = '\r';
940 str--;
941 n++;
942 continue;
943 }
944 if (use_cr)
945 use_cr = 0;
946 buf[chunk] = *str;
947 }
948 if (chunk > 0) {
949 dbgp_bulk_write(USB_DEBUG_DEVNUM,
950 dbgp_endpoint_out, buf, chunk);
951 }
952 }
953 if (unlikely(reset_run)) {
954 cmd = readl(&ehci_regs->command);
955 cmd &= ~CMD_RUN;
956 writel(cmd, &ehci_regs->command);
957 }
958}
959
960struct console early_dbgp_console = {
961 .name = "earlydbg",
962 .write = early_dbgp_write,
963 .flags = CON_PRINTBUFFER,
964 .index = -1,
965};
966
967#if IS_ENABLED(CONFIG_USB)
968int dbgp_reset_prep(struct usb_hcd *hcd)
969{
970 int ret = xen_dbgp_reset_prep(hcd);
971 u32 ctrl;
972
973 if (ret)
974 return ret;
975
976 dbgp_not_safe = 1;
977 if (!ehci_debug)
978 return 0;
979
980 if ((early_dbgp_console.index != -1 &&
981 !(early_dbgp_console.flags & CON_BOOT)) ||
982 dbgp_kgdb_mode)
983 return 1;
984 /* This means the console is not initialized, or should get
985 * shutdown so as to allow for reuse of the usb device, which
986 * means it is time to shutdown the usb debug port. */
987 ctrl = readl(&ehci_debug->control);
988 if (ctrl & DBGP_ENABLED) {
989 ctrl &= ~(DBGP_CLAIM);
990 writel(ctrl, &ehci_debug->control);
991 }
992 return 0;
993}
994EXPORT_SYMBOL_GPL(dbgp_reset_prep);
995
996int dbgp_external_startup(struct usb_hcd *hcd)
997{
998 return xen_dbgp_external_startup(hcd) ?: _dbgp_external_startup();
999}
1000EXPORT_SYMBOL_GPL(dbgp_external_startup);
1001#endif /* USB */
1002
1003#ifdef CONFIG_KGDB
1004
1005static char kgdbdbgp_buf[DBGP_MAX_PACKET];
1006static int kgdbdbgp_buf_sz;
1007static int kgdbdbgp_buf_idx;
1008static int kgdbdbgp_loop_cnt = DBGP_LOOPS;
1009
1010static int kgdbdbgp_read_char(void)
1011{
1012 int ret;
1013
1014 if (kgdbdbgp_buf_idx < kgdbdbgp_buf_sz) {
1015 char ch = kgdbdbgp_buf[kgdbdbgp_buf_idx++];
1016 return ch;
1017 }
1018
1019 ret = dbgp_bulk_read(USB_DEBUG_DEVNUM, dbgp_endpoint_in,
1020 &kgdbdbgp_buf, DBGP_MAX_PACKET,
1021 kgdbdbgp_loop_cnt);
1022 if (ret <= 0)
1023 return NO_POLL_CHAR;
1024 kgdbdbgp_buf_sz = ret;
1025 kgdbdbgp_buf_idx = 1;
1026 return kgdbdbgp_buf[0];
1027}
1028
1029static void kgdbdbgp_write_char(u8 chr)
1030{
1031 early_dbgp_write(NULL, &chr, 1);
1032}
1033
1034static struct kgdb_io kgdbdbgp_io_ops = {
1035 .name = "kgdbdbgp",
1036 .read_char = kgdbdbgp_read_char,
1037 .write_char = kgdbdbgp_write_char,
1038};
1039
1040static int kgdbdbgp_wait_time;
1041
1042static int __init kgdbdbgp_parse_config(char *str)
1043{
1044 char *ptr;
1045
1046 if (!ehci_debug) {
1047 if (early_dbgp_init(str))
1048 return -1;
1049 }
1050 ptr = strchr(str, ',');
1051 if (ptr) {
1052 ptr++;
1053 kgdbdbgp_wait_time = simple_strtoul(ptr, &ptr, 10);
1054 }
1055 kgdb_register_io_module(&kgdbdbgp_io_ops);
1056 if (early_dbgp_console.index != -1)
1057 kgdbdbgp_io_ops.cons = &early_dbgp_console;
1058
1059 return 0;
1060}
1061early_param("kgdbdbgp", kgdbdbgp_parse_config);
1062
1063static int kgdbdbgp_reader_thread(void *ptr)
1064{
1065 int ret;
1066
1067 while (readl(&ehci_debug->control) & DBGP_ENABLED) {
1068 kgdbdbgp_loop_cnt = 1;
1069 ret = kgdbdbgp_read_char();
1070 kgdbdbgp_loop_cnt = DBGP_LOOPS;
1071 if (ret != NO_POLL_CHAR) {
1072 if (ret == 0x3 || ret == '$') {
1073 if (ret == '$')
1074 kgdbdbgp_buf_idx--;
1075 kgdb_breakpoint();
1076 }
1077 continue;
1078 }
1079 schedule_timeout_interruptible(kgdbdbgp_wait_time * HZ);
1080 }
1081 return 0;
1082}
1083
1084static int __init kgdbdbgp_start_thread(void)
1085{
1086 if (dbgp_kgdb_mode && kgdbdbgp_wait_time)
1087 kthread_run(kgdbdbgp_reader_thread, NULL, "%s", "dbgp");
1088
1089 return 0;
1090}
1091device_initcall(kgdbdbgp_start_thread);
1092#endif /* CONFIG_KGDB */
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Standalone EHCI usb debug driver
4 *
5 * Originally written by:
6 * Eric W. Biederman" <ebiederm@xmission.com> and
7 * Yinghai Lu <yhlu.kernel@gmail.com>
8 *
9 * Changes for early/late printk and HW errata:
10 * Jason Wessel <jason.wessel@windriver.com>
11 * Copyright (C) 2009 Wind River Systems, Inc.
12 *
13 */
14
15#include <linux/console.h>
16#include <linux/errno.h>
17#include <linux/init.h>
18#include <linux/pci_regs.h>
19#include <linux/pci_ids.h>
20#include <linux/usb/ch9.h>
21#include <linux/usb/ehci_def.h>
22#include <linux/delay.h>
23#include <linux/serial_core.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
55static int dbgp_phys_port = 1;
56
57static struct ehci_caps __iomem *ehci_caps;
58static struct ehci_regs __iomem *ehci_regs;
59static struct ehci_dbg_port __iomem *ehci_debug;
60static int dbgp_not_safe; /* Cannot use debug device during ehci reset */
61static unsigned int dbgp_endpoint_out;
62static unsigned int dbgp_endpoint_in;
63
64struct ehci_dev {
65 u32 bus;
66 u32 slot;
67 u32 func;
68};
69
70static struct ehci_dev ehci_dev;
71
72#define USB_DEBUG_DEVNUM 127
73
74#ifdef DBGP_DEBUG
75#define dbgp_printk printk
76static 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
90static inline void dbgp_ehci_status(char *str) { }
91static inline void dbgp_printk(const char *fmt, ...) { }
92#endif
93
94static inline u32 dbgp_len_update(u32 x, u32 len)
95{
96 return (x & ~0x0f) | (len & 0x0f);
97}
98
99#ifdef CONFIG_KGDB
100static 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
149static 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
156static inline u32 dbgp_pid_read_update(u32 x, u32 tok)
157{
158 return (x & 0xffff0000) | (USB_PID_DATA0 << 8) | (tok & 0xff);
159}
160
161static 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
185static 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
195static void dbgp_breath(void)
196{
197 /* Sleep to give the debug port a chance to breathe */
198}
199
200static int dbgp_wait_until_done(unsigned ctrl, int loop)
201{
202 u32 pids, lpid;
203 int ret;
204
205retry:
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
241static 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
256static 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
270static 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
298static 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
329static 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 */
369static 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
395static 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
406static 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
431static 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
470static 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}
490static 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 */
495static 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
506try_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
557try_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 dbgp_printk("debug device renamed to 127\n");
585 }
586
587 /* Enable the debug interface */
588 ret = dbgp_control_msg(USB_DEBUG_DEVNUM,
589 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
590 USB_REQ_SET_FEATURE, USB_DEVICE_DEBUG_MODE, 0, NULL, 0);
591 if (ret < 0) {
592 dbgp_printk(" Could not enable the debug device\n");
593 goto err;
594 }
595 dbgp_printk("debug interface enabled\n");
596 /* Perform a small write to get the even/odd data state in sync
597 */
598 ret = dbgp_bulk_write(USB_DEBUG_DEVNUM, dbgp_endpoint_out, " ", 1);
599 if (ret < 0) {
600 dbgp_printk("dbgp_bulk_write failed: %d\n", ret);
601 goto err;
602 }
603 dbgp_printk("small write done\n");
604 dbgp_not_safe = 0;
605
606 return 0;
607err:
608 if (tries--)
609 goto try_again;
610 return -ENODEV;
611}
612
613static int ehci_reset_port(int port)
614{
615 u32 portsc;
616 u32 delay_time, delay;
617 int loop;
618
619 dbgp_ehci_status("reset port");
620 /* Reset the usb debug port */
621 portsc = readl(&ehci_regs->port_status[port - 1]);
622 portsc &= ~PORT_PE;
623 portsc |= PORT_RESET;
624 writel(portsc, &ehci_regs->port_status[port - 1]);
625
626 delay = HUB_ROOT_RESET_TIME;
627 for (delay_time = 0; delay_time < HUB_RESET_TIMEOUT;
628 delay_time += delay) {
629 dbgp_mdelay(delay);
630 portsc = readl(&ehci_regs->port_status[port - 1]);
631 if (!(portsc & PORT_RESET))
632 break;
633 }
634 if (portsc & PORT_RESET) {
635 /* force reset to complete */
636 loop = 100 * 1000;
637 writel(portsc & ~(PORT_RWC_BITS | PORT_RESET),
638 &ehci_regs->port_status[port - 1]);
639 do {
640 udelay(1);
641 portsc = readl(&ehci_regs->port_status[port-1]);
642 } while ((portsc & PORT_RESET) && (--loop > 0));
643 }
644
645 /* Device went away? */
646 if (!(portsc & PORT_CONNECT))
647 return -ENOTCONN;
648
649 /* bomb out completely if something weird happened */
650 if ((portsc & PORT_CSC))
651 return -EINVAL;
652
653 /* If we've finished resetting, then break out of the loop */
654 if (!(portsc & PORT_RESET) && (portsc & PORT_PE))
655 return 0;
656 return -EBUSY;
657}
658
659static int ehci_wait_for_port(int port)
660{
661 u32 status;
662 int ret, reps;
663
664 for (reps = 0; reps < 300; reps++) {
665 status = readl(&ehci_regs->status);
666 if (status & STS_PCD)
667 break;
668 dbgp_mdelay(1);
669 }
670 ret = ehci_reset_port(port);
671 if (ret == 0)
672 return 0;
673 return -ENOTCONN;
674}
675
676typedef void (*set_debug_port_t)(int port);
677
678static void __init default_set_debug_port(int port)
679{
680}
681
682static set_debug_port_t __initdata set_debug_port = default_set_debug_port;
683
684static void __init nvidia_set_debug_port(int port)
685{
686 u32 dword;
687 dword = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
688 0x74);
689 dword &= ~(0x0f<<12);
690 dword |= ((port & 0x0f)<<12);
691 write_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func, 0x74,
692 dword);
693 dbgp_printk("set debug port to %d\n", port);
694}
695
696static void __init detect_set_debug_port(void)
697{
698 u32 vendorid;
699
700 vendorid = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
701 0x00);
702
703 if ((vendorid & 0xffff) == 0x10de) {
704 dbgp_printk("using nvidia set_debug_port\n");
705 set_debug_port = nvidia_set_debug_port;
706 }
707}
708
709/* The code in early_ehci_bios_handoff() is derived from the usb pci
710 * quirk initialization, but altered so as to use the early PCI
711 * routines. */
712#define EHCI_USBLEGSUP_BIOS (1 << 16) /* BIOS semaphore */
713#define EHCI_USBLEGCTLSTS 4 /* legacy control/status */
714static void __init early_ehci_bios_handoff(void)
715{
716 u32 hcc_params = readl(&ehci_caps->hcc_params);
717 int offset = (hcc_params >> 8) & 0xff;
718 u32 cap;
719 int msec;
720
721 if (!offset)
722 return;
723
724 cap = read_pci_config(ehci_dev.bus, ehci_dev.slot,
725 ehci_dev.func, offset);
726 dbgp_printk("dbgp: ehci BIOS state %08x\n", cap);
727
728 if ((cap & 0xff) == 1 && (cap & EHCI_USBLEGSUP_BIOS)) {
729 dbgp_printk("dbgp: BIOS handoff\n");
730 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot,
731 ehci_dev.func, offset + 3, 1);
732 }
733
734 /* if boot firmware now owns EHCI, spin till it hands it over. */
735 msec = 1000;
736 while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
737 mdelay(10);
738 msec -= 10;
739 cap = read_pci_config(ehci_dev.bus, ehci_dev.slot,
740 ehci_dev.func, offset);
741 }
742
743 if (cap & EHCI_USBLEGSUP_BIOS) {
744 /* well, possibly buggy BIOS... try to shut it down,
745 * and hope nothing goes too wrong */
746 dbgp_printk("dbgp: BIOS handoff failed: %08x\n", cap);
747 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot,
748 ehci_dev.func, offset + 2, 0);
749 }
750
751 /* just in case, always disable EHCI SMIs */
752 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
753 offset + EHCI_USBLEGCTLSTS, 0);
754}
755
756static int __init ehci_setup(void)
757{
758 u32 ctrl, portsc, hcs_params;
759 u32 debug_port, new_debug_port = 0, n_ports;
760 int ret, i;
761 int port_map_tried;
762 int playtimes = 3;
763
764 early_ehci_bios_handoff();
765
766try_next_time:
767 port_map_tried = 0;
768
769try_next_port:
770
771 hcs_params = readl(&ehci_caps->hcs_params);
772 debug_port = HCS_DEBUG_PORT(hcs_params);
773 dbgp_phys_port = debug_port;
774 n_ports = HCS_N_PORTS(hcs_params);
775
776 dbgp_printk("debug_port: %d\n", debug_port);
777 dbgp_printk("n_ports: %d\n", n_ports);
778 dbgp_ehci_status("");
779
780 for (i = 1; i <= n_ports; i++) {
781 portsc = readl(&ehci_regs->port_status[i-1]);
782 dbgp_printk("portstatus%d: %08x\n", i, portsc);
783 }
784
785 if (port_map_tried && (new_debug_port != debug_port)) {
786 if (--playtimes) {
787 set_debug_port(new_debug_port);
788 goto try_next_time;
789 }
790 return -1;
791 }
792
793 /* Only reset the controller if it is not already in the
794 * configured state */
795 if (!(readl(&ehci_regs->configured_flag) & FLAG_CF)) {
796 if (dbgp_ehci_controller_reset() != 0)
797 return -1;
798 } else {
799 dbgp_ehci_status("ehci skip - already configured");
800 }
801
802 ret = _dbgp_external_startup();
803 if (ret == -EIO)
804 goto next_debug_port;
805
806 if (ret < 0) {
807 /* Things didn't work so remove my claim */
808 ctrl = readl(&ehci_debug->control);
809 ctrl &= ~(DBGP_CLAIM | DBGP_OUT);
810 writel(ctrl, &ehci_debug->control);
811 return -1;
812 }
813 return 0;
814
815next_debug_port:
816 port_map_tried |= (1<<(debug_port - 1));
817 new_debug_port = ((debug_port-1+1)%n_ports) + 1;
818 if (port_map_tried != ((1<<n_ports) - 1)) {
819 set_debug_port(new_debug_port);
820 goto try_next_port;
821 }
822 if (--playtimes) {
823 set_debug_port(new_debug_port);
824 goto try_next_time;
825 }
826
827 return -1;
828}
829
830int __init early_dbgp_init(char *s)
831{
832 u32 debug_port, bar, offset;
833 u32 bus, slot, func, cap;
834 void __iomem *ehci_bar;
835 u32 dbgp_num;
836 u32 bar_val;
837 char *e;
838 int ret;
839 u8 byte;
840
841 if (!early_pci_allowed())
842 return -1;
843
844 dbgp_num = 0;
845 if (*s)
846 dbgp_num = simple_strtoul(s, &e, 10);
847 dbgp_printk("dbgp_num: %d\n", dbgp_num);
848
849 cap = find_dbgp(dbgp_num, &bus, &slot, &func);
850 if (!cap)
851 return -1;
852
853 dbgp_printk("Found EHCI debug port on %02x:%02x.%1x\n", bus, slot,
854 func);
855
856 debug_port = read_pci_config(bus, slot, func, cap);
857 bar = (debug_port >> 29) & 0x7;
858 bar = (bar * 4) + 0xc;
859 offset = (debug_port >> 16) & 0xfff;
860 dbgp_printk("bar: %02x offset: %03x\n", bar, offset);
861 if (bar != PCI_BASE_ADDRESS_0) {
862 dbgp_printk("only debug ports on bar 1 handled.\n");
863
864 return -1;
865 }
866
867 bar_val = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
868 dbgp_printk("bar_val: %02x offset: %03x\n", bar_val, offset);
869 if (bar_val & ~PCI_BASE_ADDRESS_MEM_MASK) {
870 dbgp_printk("only simple 32bit mmio bars supported\n");
871
872 return -1;
873 }
874
875 /* double check if the mem space is enabled */
876 byte = read_pci_config_byte(bus, slot, func, 0x04);
877 if (!(byte & 0x2)) {
878 byte |= 0x02;
879 write_pci_config_byte(bus, slot, func, 0x04, byte);
880 dbgp_printk("mmio for ehci enabled\n");
881 }
882
883 /*
884 * FIXME I don't have the bar size so just guess PAGE_SIZE is more
885 * than enough. 1K is the biggest I have seen.
886 */
887 set_fixmap_nocache(FIX_DBGP_BASE, bar_val & PAGE_MASK);
888 ehci_bar = (void __iomem *)__fix_to_virt(FIX_DBGP_BASE);
889 ehci_bar += bar_val & ~PAGE_MASK;
890 dbgp_printk("ehci_bar: %p\n", ehci_bar);
891
892 ehci_caps = ehci_bar;
893 ehci_regs = ehci_bar + EARLY_HC_LENGTH(readl(&ehci_caps->hc_capbase));
894 ehci_debug = ehci_bar + offset;
895 ehci_dev.bus = bus;
896 ehci_dev.slot = slot;
897 ehci_dev.func = func;
898
899 detect_set_debug_port();
900
901 ret = ehci_setup();
902 if (ret < 0) {
903 dbgp_printk("ehci_setup failed\n");
904 ehci_debug = NULL;
905
906 return -1;
907 }
908 dbgp_ehci_status("early_init_complete");
909
910 return 0;
911}
912
913static void early_dbgp_write(struct console *con, const char *str, u32 n)
914{
915 int chunk;
916 char buf[DBGP_MAX_PACKET];
917 int use_cr = 0;
918 u32 cmd, ctrl;
919 int reset_run = 0;
920
921 if (!ehci_debug || dbgp_not_safe)
922 return;
923
924 cmd = readl(&ehci_regs->command);
925 if (unlikely(!(cmd & CMD_RUN))) {
926 /* If the ehci controller is not in the run state do extended
927 * checks to see if the acpi or some other initialization also
928 * reset the ehci debug port */
929 ctrl = readl(&ehci_debug->control);
930 if (!(ctrl & DBGP_ENABLED)) {
931 dbgp_not_safe = 1;
932 _dbgp_external_startup();
933 } else {
934 cmd |= CMD_RUN;
935 writel(cmd, &ehci_regs->command);
936 reset_run = 1;
937 }
938 }
939 while (n > 0) {
940 for (chunk = 0; chunk < DBGP_MAX_PACKET && n > 0;
941 str++, chunk++, n--) {
942 if (!use_cr && *str == '\n') {
943 use_cr = 1;
944 buf[chunk] = '\r';
945 str--;
946 n++;
947 continue;
948 }
949 if (use_cr)
950 use_cr = 0;
951 buf[chunk] = *str;
952 }
953 if (chunk > 0) {
954 dbgp_bulk_write(USB_DEBUG_DEVNUM,
955 dbgp_endpoint_out, buf, chunk);
956 }
957 }
958 if (unlikely(reset_run)) {
959 cmd = readl(&ehci_regs->command);
960 cmd &= ~CMD_RUN;
961 writel(cmd, &ehci_regs->command);
962 }
963}
964
965struct console early_dbgp_console = {
966 .name = "earlydbg",
967 .write = early_dbgp_write,
968 .flags = CON_PRINTBUFFER,
969 .index = -1,
970};
971
972#if IS_ENABLED(CONFIG_USB)
973int dbgp_reset_prep(struct usb_hcd *hcd)
974{
975 int ret = xen_dbgp_reset_prep(hcd);
976 u32 ctrl;
977
978 if (ret)
979 return ret;
980
981 dbgp_not_safe = 1;
982 if (!ehci_debug)
983 return 0;
984
985 if ((early_dbgp_console.index != -1 &&
986 !(early_dbgp_console.flags & CON_BOOT)) ||
987 dbgp_kgdb_mode)
988 return 1;
989 /* This means the console is not initialized, or should get
990 * shutdown so as to allow for reuse of the usb device, which
991 * means it is time to shutdown the usb debug port. */
992 ctrl = readl(&ehci_debug->control);
993 if (ctrl & DBGP_ENABLED) {
994 ctrl &= ~(DBGP_CLAIM);
995 writel(ctrl, &ehci_debug->control);
996 }
997 return 0;
998}
999EXPORT_SYMBOL_GPL(dbgp_reset_prep);
1000
1001int dbgp_external_startup(struct usb_hcd *hcd)
1002{
1003 return xen_dbgp_external_startup(hcd) ?: _dbgp_external_startup();
1004}
1005EXPORT_SYMBOL_GPL(dbgp_external_startup);
1006#endif /* USB */
1007
1008#ifdef CONFIG_KGDB
1009
1010static char kgdbdbgp_buf[DBGP_MAX_PACKET];
1011static int kgdbdbgp_buf_sz;
1012static int kgdbdbgp_buf_idx;
1013static int kgdbdbgp_loop_cnt = DBGP_LOOPS;
1014
1015static int kgdbdbgp_read_char(void)
1016{
1017 int ret;
1018
1019 if (kgdbdbgp_buf_idx < kgdbdbgp_buf_sz) {
1020 char ch = kgdbdbgp_buf[kgdbdbgp_buf_idx++];
1021 return ch;
1022 }
1023
1024 ret = dbgp_bulk_read(USB_DEBUG_DEVNUM, dbgp_endpoint_in,
1025 &kgdbdbgp_buf, DBGP_MAX_PACKET,
1026 kgdbdbgp_loop_cnt);
1027 if (ret <= 0)
1028 return NO_POLL_CHAR;
1029 kgdbdbgp_buf_sz = ret;
1030 kgdbdbgp_buf_idx = 1;
1031 return kgdbdbgp_buf[0];
1032}
1033
1034static void kgdbdbgp_write_char(u8 chr)
1035{
1036 early_dbgp_write(NULL, &chr, 1);
1037}
1038
1039static struct kgdb_io kgdbdbgp_io_ops = {
1040 .name = "kgdbdbgp",
1041 .read_char = kgdbdbgp_read_char,
1042 .write_char = kgdbdbgp_write_char,
1043};
1044
1045static int kgdbdbgp_wait_time;
1046
1047static int __init kgdbdbgp_parse_config(char *str)
1048{
1049 char *ptr;
1050
1051 if (!ehci_debug) {
1052 if (early_dbgp_init(str))
1053 return -1;
1054 }
1055 ptr = strchr(str, ',');
1056 if (ptr) {
1057 ptr++;
1058 kgdbdbgp_wait_time = simple_strtoul(ptr, &ptr, 10);
1059 }
1060 kgdb_register_io_module(&kgdbdbgp_io_ops);
1061 if (early_dbgp_console.index != -1)
1062 kgdbdbgp_io_ops.cons = &early_dbgp_console;
1063
1064 return 0;
1065}
1066early_param("kgdbdbgp", kgdbdbgp_parse_config);
1067
1068static 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
1089static 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}
1096device_initcall(kgdbdbgp_start_thread);
1097#endif /* CONFIG_KGDB */