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
56 static int dbgp_phys_port = 1;
57
58 static struct ehci_caps __iomem *ehci_caps;
59 static struct ehci_regs __iomem *ehci_regs;
60 static struct ehci_dbg_port __iomem *ehci_debug;
61 static int dbgp_not_safe; /* Cannot use debug device during ehci reset */
62 static unsigned int dbgp_endpoint_out;
63 static unsigned int dbgp_endpoint_in;
64
65 struct ehci_dev {
66 u32 bus;
67 u32 slot;
68 u32 func;
69 };
70
71 static struct ehci_dev ehci_dev;
72
73 #define USB_DEBUG_DEVNUM 127
74
75 #ifdef DBGP_DEBUG
76 #define dbgp_printk printk
dbgp_ehci_status(char * str)77 static 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
dbgp_ehci_status(char * str)91 static inline void dbgp_ehci_status(char *str) { }
dbgp_printk(const char * fmt,...)92 static inline void dbgp_printk(const char *fmt, ...) { }
93 #endif
94
dbgp_len_update(u32 x,u32 len)95 static inline u32 dbgp_len_update(u32 x, u32 len)
96 {
97 return (x & ~0x0f) | (len & 0x0f);
98 }
99
100 #ifdef CONFIG_KGDB
101 static 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
dbgp_pid_write_update(u32 x,u32 tok)150 static 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
dbgp_pid_read_update(u32 x,u32 tok)157 static inline u32 dbgp_pid_read_update(u32 x, u32 tok)
158 {
159 return (x & 0xffff0000) | (USB_PID_DATA0 << 8) | (tok & 0xff);
160 }
161
dbgp_wait_until_complete(void)162 static 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
dbgp_mdelay(int ms)180 static 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
dbgp_breath(void)190 static void dbgp_breath(void)
191 {
192 /* Sleep to give the debug port a chance to breathe */
193 }
194
dbgp_wait_until_done(unsigned ctrl,int loop)195 static int dbgp_wait_until_done(unsigned ctrl, int loop)
196 {
197 u32 pids, lpid;
198 int ret;
199
200 retry:
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
dbgp_set_data(const void * buf,int size)236 static 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
dbgp_get_data(void * buf,int size)251 static 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
dbgp_bulk_write(unsigned devnum,unsigned endpoint,const char * bytes,int size)265 static 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
dbgp_bulk_read(unsigned devnum,unsigned endpoint,void * data,int size,int loops)293 static 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
dbgp_control_msg(unsigned devnum,int requesttype,int request,int value,int index,void * data,int size)324 static 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 */
find_cap(u32 num,u32 slot,u32 func,int cap)364 static 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
__find_dbgp(u32 bus,u32 slot,u32 func)390 static 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
find_dbgp(int ehci_num,u32 * rbus,u32 * rslot,u32 * rfunc)401 static 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
dbgp_ehci_startup(void)426 static 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
dbgp_ehci_controller_reset(void)465 static 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 }
485 static 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 */
_dbgp_external_startup(void)490 static 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
501 try_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
552 try_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;
602 err:
603 if (tries--)
604 goto try_again;
605 return -ENODEV;
606 }
607
ehci_reset_port(int port)608 static 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
ehci_wait_for_port(int port)654 static 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
671 typedef void (*set_debug_port_t)(int port);
672
default_set_debug_port(int port)673 static void __init default_set_debug_port(int port)
674 {
675 }
676
677 static set_debug_port_t __initdata set_debug_port = default_set_debug_port;
678
nvidia_set_debug_port(int port)679 static 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
detect_set_debug_port(void)691 static 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 */
early_ehci_bios_handoff(void)709 static 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
ehci_setup(void)751 static 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
761 try_next_time:
762 port_map_tried = 0;
763
764 try_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
810 next_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
early_dbgp_init(char * s)825 int __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
early_dbgp_write(struct console * con,const char * str,u32 n)908 static 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
960 struct 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)
dbgp_reset_prep(struct usb_hcd * hcd)968 int 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 }
994 EXPORT_SYMBOL_GPL(dbgp_reset_prep);
995
dbgp_external_startup(struct usb_hcd * hcd)996 int dbgp_external_startup(struct usb_hcd *hcd)
997 {
998 return xen_dbgp_external_startup(hcd) ?: _dbgp_external_startup();
999 }
1000 EXPORT_SYMBOL_GPL(dbgp_external_startup);
1001 #endif /* USB */
1002
1003 #ifdef CONFIG_KGDB
1004
1005 static char kgdbdbgp_buf[DBGP_MAX_PACKET];
1006 static int kgdbdbgp_buf_sz;
1007 static int kgdbdbgp_buf_idx;
1008 static int kgdbdbgp_loop_cnt = DBGP_LOOPS;
1009
kgdbdbgp_read_char(void)1010 static 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
kgdbdbgp_write_char(u8 chr)1029 static void kgdbdbgp_write_char(u8 chr)
1030 {
1031 early_dbgp_write(NULL, &chr, 1);
1032 }
1033
1034 static struct kgdb_io kgdbdbgp_io_ops = {
1035 .name = "kgdbdbgp",
1036 .read_char = kgdbdbgp_read_char,
1037 .write_char = kgdbdbgp_write_char,
1038 };
1039
1040 static int kgdbdbgp_wait_time;
1041
kgdbdbgp_parse_config(char * str)1042 static 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 }
1061 early_param("kgdbdbgp", kgdbdbgp_parse_config);
1062
kgdbdbgp_reader_thread(void * ptr)1063 static 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
kgdbdbgp_start_thread(void)1084 static 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 }
1091 device_initcall(kgdbdbgp_start_thread);
1092 #endif /* CONFIG_KGDB */
1093