1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * xhci-dbc.c - xHCI debug capability early driver
4 *
5 * Copyright (C) 2016 Intel Corporation
6 *
7 * Author: Lu Baolu <baolu.lu@linux.intel.com>
8 */
9
10 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
11
12 #include <linux/console.h>
13 #include <linux/pci_regs.h>
14 #include <linux/pci_ids.h>
15 #include <linux/memblock.h>
16 #include <linux/io.h>
17 #include <asm/pci-direct.h>
18 #include <asm/fixmap.h>
19 #include <linux/bcd.h>
20 #include <linux/export.h>
21 #include <linux/module.h>
22 #include <linux/delay.h>
23 #include <linux/kthread.h>
24 #include <linux/usb/xhci-dbgp.h>
25
26 #include "../host/xhci.h"
27 #include "xhci-dbc.h"
28
29 static struct xdbc_state xdbc;
30 static bool early_console_keep;
31
32 #ifdef XDBC_TRACE
33 #define xdbc_trace trace_printk
34 #else
xdbc_trace(const char * fmt,...)35 static inline void xdbc_trace(const char *fmt, ...) { }
36 #endif /* XDBC_TRACE */
37
xdbc_map_pci_mmio(u32 bus,u32 dev,u32 func)38 static void __iomem * __init xdbc_map_pci_mmio(u32 bus, u32 dev, u32 func)
39 {
40 u64 val64, sz64, mask64;
41 void __iomem *base;
42 u32 val, sz;
43 u8 byte;
44
45 val = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0);
46 write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0, ~0);
47 sz = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0);
48 write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0, val);
49
50 if (val == 0xffffffff || sz == 0xffffffff) {
51 pr_notice("invalid mmio bar\n");
52 return NULL;
53 }
54
55 val64 = val & PCI_BASE_ADDRESS_MEM_MASK;
56 sz64 = sz & PCI_BASE_ADDRESS_MEM_MASK;
57 mask64 = PCI_BASE_ADDRESS_MEM_MASK;
58
59 if ((val & PCI_BASE_ADDRESS_MEM_TYPE_MASK) == PCI_BASE_ADDRESS_MEM_TYPE_64) {
60 val = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4);
61 write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4, ~0);
62 sz = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4);
63 write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4, val);
64
65 val64 |= (u64)val << 32;
66 sz64 |= (u64)sz << 32;
67 mask64 |= ~0ULL << 32;
68 }
69
70 sz64 &= mask64;
71
72 if (!sz64) {
73 pr_notice("invalid mmio address\n");
74 return NULL;
75 }
76
77 sz64 = 1ULL << __ffs64(sz64);
78
79 /* Check if the mem space is enabled: */
80 byte = read_pci_config_byte(bus, dev, func, PCI_COMMAND);
81 if (!(byte & PCI_COMMAND_MEMORY)) {
82 byte |= PCI_COMMAND_MEMORY;
83 write_pci_config_byte(bus, dev, func, PCI_COMMAND, byte);
84 }
85
86 xdbc.xhci_start = val64;
87 xdbc.xhci_length = sz64;
88 base = early_ioremap(val64, sz64);
89
90 return base;
91 }
92
xdbc_get_page(dma_addr_t * dma_addr)93 static void * __init xdbc_get_page(dma_addr_t *dma_addr)
94 {
95 void *virt;
96
97 virt = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
98 if (!virt)
99 return NULL;
100
101 if (dma_addr)
102 *dma_addr = (dma_addr_t)__pa(virt);
103
104 return virt;
105 }
106
xdbc_find_dbgp(int xdbc_num,u32 * b,u32 * d,u32 * f)107 static u32 __init xdbc_find_dbgp(int xdbc_num, u32 *b, u32 *d, u32 *f)
108 {
109 u32 bus, dev, func, class;
110
111 for (bus = 0; bus < XDBC_PCI_MAX_BUSES; bus++) {
112 for (dev = 0; dev < XDBC_PCI_MAX_DEVICES; dev++) {
113 for (func = 0; func < XDBC_PCI_MAX_FUNCTION; func++) {
114
115 class = read_pci_config(bus, dev, func, PCI_CLASS_REVISION);
116 if ((class >> 8) != PCI_CLASS_SERIAL_USB_XHCI)
117 continue;
118
119 if (xdbc_num-- != 0)
120 continue;
121
122 *b = bus;
123 *d = dev;
124 *f = func;
125
126 return 0;
127 }
128 }
129 }
130
131 return -1;
132 }
133
handshake(void __iomem * ptr,u32 mask,u32 done,int wait,int delay)134 static int handshake(void __iomem *ptr, u32 mask, u32 done, int wait, int delay)
135 {
136 u32 result;
137
138 /* Can not use readl_poll_timeout_atomic() for early boot things */
139 do {
140 result = readl(ptr);
141 result &= mask;
142 if (result == done)
143 return 0;
144 udelay(delay);
145 wait -= delay;
146 } while (wait > 0);
147
148 return -ETIMEDOUT;
149 }
150
xdbc_bios_handoff(void)151 static void __init xdbc_bios_handoff(void)
152 {
153 int offset, timeout;
154 u32 val;
155
156 offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_LEGACY);
157 val = readl(xdbc.xhci_base + offset);
158
159 if (val & XHCI_HC_BIOS_OWNED) {
160 writel(val | XHCI_HC_OS_OWNED, xdbc.xhci_base + offset);
161 timeout = handshake(xdbc.xhci_base + offset, XHCI_HC_BIOS_OWNED, 0, 5000, 10);
162
163 if (timeout) {
164 pr_notice("failed to hand over xHCI control from BIOS\n");
165 writel(val & ~XHCI_HC_BIOS_OWNED, xdbc.xhci_base + offset);
166 }
167 }
168
169 /* Disable BIOS SMIs and clear all SMI events: */
170 val = readl(xdbc.xhci_base + offset + XHCI_LEGACY_CONTROL_OFFSET);
171 val &= XHCI_LEGACY_DISABLE_SMI;
172 val |= XHCI_LEGACY_SMI_EVENTS;
173 writel(val, xdbc.xhci_base + offset + XHCI_LEGACY_CONTROL_OFFSET);
174 }
175
176 static int __init
xdbc_alloc_ring(struct xdbc_segment * seg,struct xdbc_ring * ring)177 xdbc_alloc_ring(struct xdbc_segment *seg, struct xdbc_ring *ring)
178 {
179 seg->trbs = xdbc_get_page(&seg->dma);
180 if (!seg->trbs)
181 return -ENOMEM;
182
183 ring->segment = seg;
184
185 return 0;
186 }
187
xdbc_free_ring(struct xdbc_ring * ring)188 static void __init xdbc_free_ring(struct xdbc_ring *ring)
189 {
190 struct xdbc_segment *seg = ring->segment;
191
192 if (!seg)
193 return;
194
195 memblock_free(seg->dma, PAGE_SIZE);
196 ring->segment = NULL;
197 }
198
xdbc_reset_ring(struct xdbc_ring * ring)199 static void xdbc_reset_ring(struct xdbc_ring *ring)
200 {
201 struct xdbc_segment *seg = ring->segment;
202 struct xdbc_trb *link_trb;
203
204 memset(seg->trbs, 0, PAGE_SIZE);
205
206 ring->enqueue = seg->trbs;
207 ring->dequeue = seg->trbs;
208 ring->cycle_state = 1;
209
210 if (ring != &xdbc.evt_ring) {
211 link_trb = &seg->trbs[XDBC_TRBS_PER_SEGMENT - 1];
212 link_trb->field[0] = cpu_to_le32(lower_32_bits(seg->dma));
213 link_trb->field[1] = cpu_to_le32(upper_32_bits(seg->dma));
214 link_trb->field[3] = cpu_to_le32(TRB_TYPE(TRB_LINK)) | cpu_to_le32(LINK_TOGGLE);
215 }
216 }
217
xdbc_put_utf16(u16 * s,const char * c,size_t size)218 static inline void xdbc_put_utf16(u16 *s, const char *c, size_t size)
219 {
220 int i;
221
222 for (i = 0; i < size; i++)
223 s[i] = cpu_to_le16(c[i]);
224 }
225
xdbc_mem_init(void)226 static void xdbc_mem_init(void)
227 {
228 struct xdbc_ep_context *ep_in, *ep_out;
229 struct usb_string_descriptor *s_desc;
230 struct xdbc_erst_entry *entry;
231 struct xdbc_strings *strings;
232 struct xdbc_context *ctx;
233 unsigned int max_burst;
234 u32 string_length;
235 int index = 0;
236 u32 dev_info;
237
238 xdbc_reset_ring(&xdbc.evt_ring);
239 xdbc_reset_ring(&xdbc.in_ring);
240 xdbc_reset_ring(&xdbc.out_ring);
241 memset(xdbc.table_base, 0, PAGE_SIZE);
242 memset(xdbc.out_buf, 0, PAGE_SIZE);
243
244 /* Initialize event ring segment table: */
245 xdbc.erst_size = 16;
246 xdbc.erst_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
247 xdbc.erst_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
248
249 index += XDBC_ERST_ENTRY_NUM;
250 entry = (struct xdbc_erst_entry *)xdbc.erst_base;
251
252 entry->seg_addr = cpu_to_le64(xdbc.evt_seg.dma);
253 entry->seg_size = cpu_to_le32(XDBC_TRBS_PER_SEGMENT);
254 entry->__reserved_0 = 0;
255
256 /* Initialize ERST registers: */
257 writel(1, &xdbc.xdbc_reg->ersts);
258 xdbc_write64(xdbc.erst_dma, &xdbc.xdbc_reg->erstba);
259 xdbc_write64(xdbc.evt_seg.dma, &xdbc.xdbc_reg->erdp);
260
261 /* Debug capability contexts: */
262 xdbc.dbcc_size = 64 * 3;
263 xdbc.dbcc_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
264 xdbc.dbcc_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
265
266 index += XDBC_DBCC_ENTRY_NUM;
267
268 /* Popluate the strings: */
269 xdbc.string_size = sizeof(struct xdbc_strings);
270 xdbc.string_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
271 xdbc.string_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
272 strings = (struct xdbc_strings *)xdbc.string_base;
273
274 index += XDBC_STRING_ENTRY_NUM;
275
276 /* Serial string: */
277 s_desc = (struct usb_string_descriptor *)strings->serial;
278 s_desc->bLength = (strlen(XDBC_STRING_SERIAL) + 1) * 2;
279 s_desc->bDescriptorType = USB_DT_STRING;
280
281 xdbc_put_utf16(s_desc->wData, XDBC_STRING_SERIAL, strlen(XDBC_STRING_SERIAL));
282 string_length = s_desc->bLength;
283 string_length <<= 8;
284
285 /* Product string: */
286 s_desc = (struct usb_string_descriptor *)strings->product;
287 s_desc->bLength = (strlen(XDBC_STRING_PRODUCT) + 1) * 2;
288 s_desc->bDescriptorType = USB_DT_STRING;
289
290 xdbc_put_utf16(s_desc->wData, XDBC_STRING_PRODUCT, strlen(XDBC_STRING_PRODUCT));
291 string_length += s_desc->bLength;
292 string_length <<= 8;
293
294 /* Manufacture string: */
295 s_desc = (struct usb_string_descriptor *)strings->manufacturer;
296 s_desc->bLength = (strlen(XDBC_STRING_MANUFACTURER) + 1) * 2;
297 s_desc->bDescriptorType = USB_DT_STRING;
298
299 xdbc_put_utf16(s_desc->wData, XDBC_STRING_MANUFACTURER, strlen(XDBC_STRING_MANUFACTURER));
300 string_length += s_desc->bLength;
301 string_length <<= 8;
302
303 /* String0: */
304 strings->string0[0] = 4;
305 strings->string0[1] = USB_DT_STRING;
306 strings->string0[2] = 0x09;
307 strings->string0[3] = 0x04;
308
309 string_length += 4;
310
311 /* Populate info Context: */
312 ctx = (struct xdbc_context *)xdbc.dbcc_base;
313
314 ctx->info.string0 = cpu_to_le64(xdbc.string_dma);
315 ctx->info.manufacturer = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH);
316 ctx->info.product = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH * 2);
317 ctx->info.serial = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH * 3);
318 ctx->info.length = cpu_to_le32(string_length);
319
320 /* Populate bulk out endpoint context: */
321 max_burst = DEBUG_MAX_BURST(readl(&xdbc.xdbc_reg->control));
322 ep_out = (struct xdbc_ep_context *)&ctx->out;
323
324 ep_out->ep_info1 = 0;
325 ep_out->ep_info2 = cpu_to_le32(EP_TYPE(BULK_OUT_EP) | MAX_PACKET(1024) | MAX_BURST(max_burst));
326 ep_out->deq = cpu_to_le64(xdbc.out_seg.dma | xdbc.out_ring.cycle_state);
327
328 /* Populate bulk in endpoint context: */
329 ep_in = (struct xdbc_ep_context *)&ctx->in;
330
331 ep_in->ep_info1 = 0;
332 ep_in->ep_info2 = cpu_to_le32(EP_TYPE(BULK_IN_EP) | MAX_PACKET(1024) | MAX_BURST(max_burst));
333 ep_in->deq = cpu_to_le64(xdbc.in_seg.dma | xdbc.in_ring.cycle_state);
334
335 /* Set DbC context and info registers: */
336 xdbc_write64(xdbc.dbcc_dma, &xdbc.xdbc_reg->dccp);
337
338 dev_info = cpu_to_le32((XDBC_VENDOR_ID << 16) | XDBC_PROTOCOL);
339 writel(dev_info, &xdbc.xdbc_reg->devinfo1);
340
341 dev_info = cpu_to_le32((XDBC_DEVICE_REV << 16) | XDBC_PRODUCT_ID);
342 writel(dev_info, &xdbc.xdbc_reg->devinfo2);
343
344 xdbc.in_buf = xdbc.out_buf + XDBC_MAX_PACKET;
345 xdbc.in_dma = xdbc.out_dma + XDBC_MAX_PACKET;
346 }
347
xdbc_do_reset_debug_port(u32 id,u32 count)348 static void xdbc_do_reset_debug_port(u32 id, u32 count)
349 {
350 void __iomem *ops_reg;
351 void __iomem *portsc;
352 u32 val, cap_length;
353 int i;
354
355 cap_length = readl(xdbc.xhci_base) & 0xff;
356 ops_reg = xdbc.xhci_base + cap_length;
357
358 id--;
359 for (i = id; i < (id + count); i++) {
360 portsc = ops_reg + 0x400 + i * 0x10;
361 val = readl(portsc);
362 if (!(val & PORT_CONNECT))
363 writel(val | PORT_RESET, portsc);
364 }
365 }
366
xdbc_reset_debug_port(void)367 static void xdbc_reset_debug_port(void)
368 {
369 u32 val, port_offset, port_count;
370 int offset = 0;
371
372 do {
373 offset = xhci_find_next_ext_cap(xdbc.xhci_base, offset, XHCI_EXT_CAPS_PROTOCOL);
374 if (!offset)
375 break;
376
377 val = readl(xdbc.xhci_base + offset);
378 if (XHCI_EXT_PORT_MAJOR(val) != 0x3)
379 continue;
380
381 val = readl(xdbc.xhci_base + offset + 8);
382 port_offset = XHCI_EXT_PORT_OFF(val);
383 port_count = XHCI_EXT_PORT_COUNT(val);
384
385 xdbc_do_reset_debug_port(port_offset, port_count);
386 } while (1);
387 }
388
389 static void
xdbc_queue_trb(struct xdbc_ring * ring,u32 field1,u32 field2,u32 field3,u32 field4)390 xdbc_queue_trb(struct xdbc_ring *ring, u32 field1, u32 field2, u32 field3, u32 field4)
391 {
392 struct xdbc_trb *trb, *link_trb;
393
394 trb = ring->enqueue;
395 trb->field[0] = cpu_to_le32(field1);
396 trb->field[1] = cpu_to_le32(field2);
397 trb->field[2] = cpu_to_le32(field3);
398 trb->field[3] = cpu_to_le32(field4);
399
400 ++(ring->enqueue);
401 if (ring->enqueue >= &ring->segment->trbs[TRBS_PER_SEGMENT - 1]) {
402 link_trb = ring->enqueue;
403 if (ring->cycle_state)
404 link_trb->field[3] |= cpu_to_le32(TRB_CYCLE);
405 else
406 link_trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
407
408 ring->enqueue = ring->segment->trbs;
409 ring->cycle_state ^= 1;
410 }
411 }
412
xdbc_ring_doorbell(int target)413 static void xdbc_ring_doorbell(int target)
414 {
415 writel(DOOR_BELL_TARGET(target), &xdbc.xdbc_reg->doorbell);
416 }
417
xdbc_start(void)418 static int xdbc_start(void)
419 {
420 u32 ctrl, status;
421 int ret;
422
423 ctrl = readl(&xdbc.xdbc_reg->control);
424 writel(ctrl | CTRL_DBC_ENABLE | CTRL_PORT_ENABLE, &xdbc.xdbc_reg->control);
425 ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, CTRL_DBC_ENABLE, 100000, 100);
426 if (ret) {
427 xdbc_trace("failed to initialize hardware\n");
428 return ret;
429 }
430
431 /* Reset port to avoid bus hang: */
432 if (xdbc.vendor == PCI_VENDOR_ID_INTEL)
433 xdbc_reset_debug_port();
434
435 /* Wait for port connection: */
436 ret = handshake(&xdbc.xdbc_reg->portsc, PORTSC_CONN_STATUS, PORTSC_CONN_STATUS, 5000000, 100);
437 if (ret) {
438 xdbc_trace("waiting for connection timed out\n");
439 return ret;
440 }
441
442 /* Wait for debug device to be configured: */
443 ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_RUN, CTRL_DBC_RUN, 5000000, 100);
444 if (ret) {
445 xdbc_trace("waiting for device configuration timed out\n");
446 return ret;
447 }
448
449 /* Check port number: */
450 status = readl(&xdbc.xdbc_reg->status);
451 if (!DCST_DEBUG_PORT(status)) {
452 xdbc_trace("invalid root hub port number\n");
453 return -ENODEV;
454 }
455
456 xdbc.port_number = DCST_DEBUG_PORT(status);
457
458 xdbc_trace("DbC is running now, control 0x%08x port ID %d\n",
459 readl(&xdbc.xdbc_reg->control), xdbc.port_number);
460
461 return 0;
462 }
463
xdbc_bulk_transfer(void * data,int size,bool read)464 static int xdbc_bulk_transfer(void *data, int size, bool read)
465 {
466 struct xdbc_ring *ring;
467 struct xdbc_trb *trb;
468 u32 length, control;
469 u32 cycle;
470 u64 addr;
471
472 if (size > XDBC_MAX_PACKET) {
473 xdbc_trace("bad parameter, size %d\n", size);
474 return -EINVAL;
475 }
476
477 if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED) ||
478 !(xdbc.flags & XDBC_FLAGS_CONFIGURED) ||
479 (!read && (xdbc.flags & XDBC_FLAGS_OUT_STALL)) ||
480 (read && (xdbc.flags & XDBC_FLAGS_IN_STALL))) {
481
482 xdbc_trace("connection not ready, flags %08x\n", xdbc.flags);
483 return -EIO;
484 }
485
486 ring = (read ? &xdbc.in_ring : &xdbc.out_ring);
487 trb = ring->enqueue;
488 cycle = ring->cycle_state;
489 length = TRB_LEN(size);
490 control = TRB_TYPE(TRB_NORMAL) | TRB_IOC;
491
492 if (cycle)
493 control &= cpu_to_le32(~TRB_CYCLE);
494 else
495 control |= cpu_to_le32(TRB_CYCLE);
496
497 if (read) {
498 memset(xdbc.in_buf, 0, XDBC_MAX_PACKET);
499 addr = xdbc.in_dma;
500 xdbc.flags |= XDBC_FLAGS_IN_PROCESS;
501 } else {
502 memset(xdbc.out_buf, 0, XDBC_MAX_PACKET);
503 memcpy(xdbc.out_buf, data, size);
504 addr = xdbc.out_dma;
505 xdbc.flags |= XDBC_FLAGS_OUT_PROCESS;
506 }
507
508 xdbc_queue_trb(ring, lower_32_bits(addr), upper_32_bits(addr), length, control);
509
510 /*
511 * Add a barrier between writes of trb fields and flipping
512 * the cycle bit:
513 */
514 wmb();
515 if (cycle)
516 trb->field[3] |= cpu_to_le32(cycle);
517 else
518 trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
519
520 xdbc_ring_doorbell(read ? IN_EP_DOORBELL : OUT_EP_DOORBELL);
521
522 return size;
523 }
524
xdbc_handle_external_reset(void)525 static int xdbc_handle_external_reset(void)
526 {
527 int ret = 0;
528
529 xdbc.flags = 0;
530 writel(0, &xdbc.xdbc_reg->control);
531 ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 10);
532 if (ret)
533 goto reset_out;
534
535 xdbc_mem_init();
536
537 ret = xdbc_start();
538 if (ret < 0)
539 goto reset_out;
540
541 xdbc_trace("dbc recovered\n");
542
543 xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
544
545 xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
546
547 return 0;
548
549 reset_out:
550 xdbc_trace("failed to recover from external reset\n");
551 return ret;
552 }
553
xdbc_early_setup(void)554 static int __init xdbc_early_setup(void)
555 {
556 int ret;
557
558 writel(0, &xdbc.xdbc_reg->control);
559 ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 100);
560 if (ret)
561 return ret;
562
563 /* Allocate the table page: */
564 xdbc.table_base = xdbc_get_page(&xdbc.table_dma);
565 if (!xdbc.table_base)
566 return -ENOMEM;
567
568 /* Get and store the transfer buffer: */
569 xdbc.out_buf = xdbc_get_page(&xdbc.out_dma);
570 if (!xdbc.out_buf)
571 return -ENOMEM;
572
573 /* Allocate the event ring: */
574 ret = xdbc_alloc_ring(&xdbc.evt_seg, &xdbc.evt_ring);
575 if (ret < 0)
576 return ret;
577
578 /* Allocate IN/OUT endpoint transfer rings: */
579 ret = xdbc_alloc_ring(&xdbc.in_seg, &xdbc.in_ring);
580 if (ret < 0)
581 return ret;
582
583 ret = xdbc_alloc_ring(&xdbc.out_seg, &xdbc.out_ring);
584 if (ret < 0)
585 return ret;
586
587 xdbc_mem_init();
588
589 ret = xdbc_start();
590 if (ret < 0) {
591 writel(0, &xdbc.xdbc_reg->control);
592 return ret;
593 }
594
595 xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
596
597 xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
598
599 return 0;
600 }
601
early_xdbc_parse_parameter(char * s)602 int __init early_xdbc_parse_parameter(char *s)
603 {
604 unsigned long dbgp_num = 0;
605 u32 bus, dev, func, offset;
606 int ret;
607
608 if (!early_pci_allowed())
609 return -EPERM;
610
611 if (strstr(s, "keep"))
612 early_console_keep = true;
613
614 if (xdbc.xdbc_reg)
615 return 0;
616
617 if (*s && kstrtoul(s, 0, &dbgp_num))
618 dbgp_num = 0;
619
620 pr_notice("dbgp_num: %lu\n", dbgp_num);
621
622 /* Locate the host controller: */
623 ret = xdbc_find_dbgp(dbgp_num, &bus, &dev, &func);
624 if (ret) {
625 pr_notice("failed to locate xhci host\n");
626 return -ENODEV;
627 }
628
629 xdbc.vendor = read_pci_config_16(bus, dev, func, PCI_VENDOR_ID);
630 xdbc.device = read_pci_config_16(bus, dev, func, PCI_DEVICE_ID);
631 xdbc.bus = bus;
632 xdbc.dev = dev;
633 xdbc.func = func;
634
635 /* Map the IO memory: */
636 xdbc.xhci_base = xdbc_map_pci_mmio(bus, dev, func);
637 if (!xdbc.xhci_base)
638 return -EINVAL;
639
640 /* Locate DbC registers: */
641 offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
642 if (!offset) {
643 pr_notice("xhci host doesn't support debug capability\n");
644 early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
645 xdbc.xhci_base = NULL;
646 xdbc.xhci_length = 0;
647
648 return -ENODEV;
649 }
650 xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
651
652 return 0;
653 }
654
early_xdbc_setup_hardware(void)655 int __init early_xdbc_setup_hardware(void)
656 {
657 int ret;
658
659 if (!xdbc.xdbc_reg)
660 return -ENODEV;
661
662 xdbc_bios_handoff();
663
664 raw_spin_lock_init(&xdbc.lock);
665
666 ret = xdbc_early_setup();
667 if (ret) {
668 pr_notice("failed to setup the connection to host\n");
669
670 xdbc_free_ring(&xdbc.evt_ring);
671 xdbc_free_ring(&xdbc.out_ring);
672 xdbc_free_ring(&xdbc.in_ring);
673
674 if (xdbc.table_dma)
675 memblock_free(xdbc.table_dma, PAGE_SIZE);
676
677 if (xdbc.out_dma)
678 memblock_free(xdbc.out_dma, PAGE_SIZE);
679
680 xdbc.table_base = NULL;
681 xdbc.out_buf = NULL;
682 }
683
684 return ret;
685 }
686
xdbc_handle_port_status(struct xdbc_trb * evt_trb)687 static void xdbc_handle_port_status(struct xdbc_trb *evt_trb)
688 {
689 u32 port_reg;
690
691 port_reg = readl(&xdbc.xdbc_reg->portsc);
692 if (port_reg & PORTSC_CONN_CHANGE) {
693 xdbc_trace("connect status change event\n");
694
695 /* Check whether cable unplugged: */
696 if (!(port_reg & PORTSC_CONN_STATUS)) {
697 xdbc.flags = 0;
698 xdbc_trace("cable unplugged\n");
699 }
700 }
701
702 if (port_reg & PORTSC_RESET_CHANGE)
703 xdbc_trace("port reset change event\n");
704
705 if (port_reg & PORTSC_LINK_CHANGE)
706 xdbc_trace("port link status change event\n");
707
708 if (port_reg & PORTSC_CONFIG_CHANGE)
709 xdbc_trace("config error change\n");
710
711 /* Write back the value to clear RW1C bits: */
712 writel(port_reg, &xdbc.xdbc_reg->portsc);
713 }
714
xdbc_handle_tx_event(struct xdbc_trb * evt_trb)715 static void xdbc_handle_tx_event(struct xdbc_trb *evt_trb)
716 {
717 u32 comp_code;
718 int ep_id;
719
720 comp_code = GET_COMP_CODE(le32_to_cpu(evt_trb->field[2]));
721 ep_id = TRB_TO_EP_ID(le32_to_cpu(evt_trb->field[3]));
722
723 switch (comp_code) {
724 case COMP_SUCCESS:
725 case COMP_SHORT_PACKET:
726 break;
727 case COMP_TRB_ERROR:
728 case COMP_BABBLE_DETECTED_ERROR:
729 case COMP_USB_TRANSACTION_ERROR:
730 case COMP_STALL_ERROR:
731 default:
732 if (ep_id == XDBC_EPID_OUT || ep_id == XDBC_EPID_OUT_INTEL)
733 xdbc.flags |= XDBC_FLAGS_OUT_STALL;
734 if (ep_id == XDBC_EPID_IN || ep_id == XDBC_EPID_IN_INTEL)
735 xdbc.flags |= XDBC_FLAGS_IN_STALL;
736
737 xdbc_trace("endpoint %d stalled\n", ep_id);
738 break;
739 }
740
741 if (ep_id == XDBC_EPID_IN || ep_id == XDBC_EPID_IN_INTEL) {
742 xdbc.flags &= ~XDBC_FLAGS_IN_PROCESS;
743 xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
744 } else if (ep_id == XDBC_EPID_OUT || ep_id == XDBC_EPID_OUT_INTEL) {
745 xdbc.flags &= ~XDBC_FLAGS_OUT_PROCESS;
746 } else {
747 xdbc_trace("invalid endpoint id %d\n", ep_id);
748 }
749 }
750
xdbc_handle_events(void)751 static void xdbc_handle_events(void)
752 {
753 struct xdbc_trb *evt_trb;
754 bool update_erdp = false;
755 u32 reg;
756 u8 cmd;
757
758 cmd = read_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND);
759 if (!(cmd & PCI_COMMAND_MASTER)) {
760 cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
761 write_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND, cmd);
762 }
763
764 if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
765 return;
766
767 /* Handle external reset events: */
768 reg = readl(&xdbc.xdbc_reg->control);
769 if (!(reg & CTRL_DBC_ENABLE)) {
770 if (xdbc_handle_external_reset()) {
771 xdbc_trace("failed to recover connection\n");
772 return;
773 }
774 }
775
776 /* Handle configure-exit event: */
777 reg = readl(&xdbc.xdbc_reg->control);
778 if (reg & CTRL_DBC_RUN_CHANGE) {
779 writel(reg, &xdbc.xdbc_reg->control);
780 if (reg & CTRL_DBC_RUN)
781 xdbc.flags |= XDBC_FLAGS_CONFIGURED;
782 else
783 xdbc.flags &= ~XDBC_FLAGS_CONFIGURED;
784 }
785
786 /* Handle endpoint stall event: */
787 reg = readl(&xdbc.xdbc_reg->control);
788 if (reg & CTRL_HALT_IN_TR) {
789 xdbc.flags |= XDBC_FLAGS_IN_STALL;
790 } else {
791 xdbc.flags &= ~XDBC_FLAGS_IN_STALL;
792 if (!(xdbc.flags & XDBC_FLAGS_IN_PROCESS))
793 xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
794 }
795
796 if (reg & CTRL_HALT_OUT_TR)
797 xdbc.flags |= XDBC_FLAGS_OUT_STALL;
798 else
799 xdbc.flags &= ~XDBC_FLAGS_OUT_STALL;
800
801 /* Handle the events in the event ring: */
802 evt_trb = xdbc.evt_ring.dequeue;
803 while ((le32_to_cpu(evt_trb->field[3]) & TRB_CYCLE) == xdbc.evt_ring.cycle_state) {
804 /*
805 * Add a barrier between reading the cycle flag and any
806 * reads of the event's flags/data below:
807 */
808 rmb();
809
810 switch ((le32_to_cpu(evt_trb->field[3]) & TRB_TYPE_BITMASK)) {
811 case TRB_TYPE(TRB_PORT_STATUS):
812 xdbc_handle_port_status(evt_trb);
813 break;
814 case TRB_TYPE(TRB_TRANSFER):
815 xdbc_handle_tx_event(evt_trb);
816 break;
817 default:
818 break;
819 }
820
821 ++(xdbc.evt_ring.dequeue);
822 if (xdbc.evt_ring.dequeue == &xdbc.evt_seg.trbs[TRBS_PER_SEGMENT]) {
823 xdbc.evt_ring.dequeue = xdbc.evt_seg.trbs;
824 xdbc.evt_ring.cycle_state ^= 1;
825 }
826
827 evt_trb = xdbc.evt_ring.dequeue;
828 update_erdp = true;
829 }
830
831 /* Update event ring dequeue pointer: */
832 if (update_erdp)
833 xdbc_write64(__pa(xdbc.evt_ring.dequeue), &xdbc.xdbc_reg->erdp);
834 }
835
xdbc_bulk_write(const char * bytes,int size)836 static int xdbc_bulk_write(const char *bytes, int size)
837 {
838 int ret, timeout = 0;
839 unsigned long flags;
840
841 retry:
842 if (in_nmi()) {
843 if (!raw_spin_trylock_irqsave(&xdbc.lock, flags))
844 return -EAGAIN;
845 } else {
846 raw_spin_lock_irqsave(&xdbc.lock, flags);
847 }
848
849 xdbc_handle_events();
850
851 /* Check completion of the previous request: */
852 if ((xdbc.flags & XDBC_FLAGS_OUT_PROCESS) && (timeout < 2000000)) {
853 raw_spin_unlock_irqrestore(&xdbc.lock, flags);
854 udelay(100);
855 timeout += 100;
856 goto retry;
857 }
858
859 if (xdbc.flags & XDBC_FLAGS_OUT_PROCESS) {
860 raw_spin_unlock_irqrestore(&xdbc.lock, flags);
861 xdbc_trace("previous transfer not completed yet\n");
862
863 return -ETIMEDOUT;
864 }
865
866 ret = xdbc_bulk_transfer((void *)bytes, size, false);
867 raw_spin_unlock_irqrestore(&xdbc.lock, flags);
868
869 return ret;
870 }
871
early_xdbc_write(struct console * con,const char * str,u32 n)872 static void early_xdbc_write(struct console *con, const char *str, u32 n)
873 {
874 static char buf[XDBC_MAX_PACKET];
875 int chunk, ret;
876 int use_cr = 0;
877
878 if (!xdbc.xdbc_reg)
879 return;
880 memset(buf, 0, XDBC_MAX_PACKET);
881 while (n > 0) {
882 for (chunk = 0; chunk < XDBC_MAX_PACKET && n > 0; str++, chunk++, n--) {
883
884 if (!use_cr && *str == '\n') {
885 use_cr = 1;
886 buf[chunk] = '\r';
887 str--;
888 n++;
889 continue;
890 }
891
892 if (use_cr)
893 use_cr = 0;
894 buf[chunk] = *str;
895 }
896
897 if (chunk > 0) {
898 ret = xdbc_bulk_write(buf, chunk);
899 if (ret < 0)
900 xdbc_trace("missed message {%s}\n", buf);
901 }
902 }
903 }
904
905 static struct console early_xdbc_console = {
906 .name = "earlyxdbc",
907 .write = early_xdbc_write,
908 .flags = CON_PRINTBUFFER,
909 .index = -1,
910 };
911
early_xdbc_register_console(void)912 void __init early_xdbc_register_console(void)
913 {
914 if (early_console)
915 return;
916
917 early_console = &early_xdbc_console;
918 if (early_console_keep)
919 early_console->flags &= ~CON_BOOT;
920 else
921 early_console->flags |= CON_BOOT;
922 register_console(early_console);
923 }
924
xdbc_unregister_console(void)925 static void xdbc_unregister_console(void)
926 {
927 if (early_xdbc_console.flags & CON_ENABLED)
928 unregister_console(&early_xdbc_console);
929 }
930
xdbc_scrub_function(void * ptr)931 static int xdbc_scrub_function(void *ptr)
932 {
933 unsigned long flags;
934
935 while (true) {
936 raw_spin_lock_irqsave(&xdbc.lock, flags);
937 xdbc_handle_events();
938
939 if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED)) {
940 raw_spin_unlock_irqrestore(&xdbc.lock, flags);
941 break;
942 }
943
944 raw_spin_unlock_irqrestore(&xdbc.lock, flags);
945 schedule_timeout_interruptible(1);
946 }
947
948 xdbc_unregister_console();
949 writel(0, &xdbc.xdbc_reg->control);
950 xdbc_trace("dbc scrub function exits\n");
951
952 return 0;
953 }
954
xdbc_init(void)955 static int __init xdbc_init(void)
956 {
957 unsigned long flags;
958 void __iomem *base;
959 int ret = 0;
960 u32 offset;
961
962 if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
963 return 0;
964
965 /*
966 * It's time to shut down the DbC, so that the debug
967 * port can be reused by the host controller:
968 */
969 if (early_xdbc_console.index == -1 ||
970 (early_xdbc_console.flags & CON_BOOT)) {
971 xdbc_trace("hardware not used anymore\n");
972 goto free_and_quit;
973 }
974
975 base = ioremap(xdbc.xhci_start, xdbc.xhci_length);
976 if (!base) {
977 xdbc_trace("failed to remap the io address\n");
978 ret = -ENOMEM;
979 goto free_and_quit;
980 }
981
982 raw_spin_lock_irqsave(&xdbc.lock, flags);
983 early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
984 xdbc.xhci_base = base;
985 offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
986 xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
987 raw_spin_unlock_irqrestore(&xdbc.lock, flags);
988
989 kthread_run(xdbc_scrub_function, NULL, "%s", "xdbc");
990
991 return 0;
992
993 free_and_quit:
994 xdbc_free_ring(&xdbc.evt_ring);
995 xdbc_free_ring(&xdbc.out_ring);
996 xdbc_free_ring(&xdbc.in_ring);
997 memblock_free(xdbc.table_dma, PAGE_SIZE);
998 memblock_free(xdbc.out_dma, PAGE_SIZE);
999 writel(0, &xdbc.xdbc_reg->control);
1000 early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
1001
1002 return ret;
1003 }
1004 subsys_initcall(xdbc_init);
1005