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
29static struct xdbc_state xdbc;
30static bool early_console_keep;
31
32#ifdef XDBC_TRACE
33#define	xdbc_trace	trace_printk
34#else
35static inline void xdbc_trace(const char *fmt, ...) { }
36#endif /* XDBC_TRACE */
37
38static 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
93static 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
107static 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
134static 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
151static 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
176static int __init
177xdbc_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
188static 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_phys_free(seg->dma, PAGE_SIZE);
196	ring->segment = NULL;
197}
198
199static 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
218static 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
226static 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
348static 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
367static 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
389static void
390xdbc_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
413static void xdbc_ring_doorbell(int target)
414{
415	writel(DOOR_BELL_TARGET(target), &xdbc.xdbc_reg->doorbell);
416}
417
418static 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
464static 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		memcpy_and_pad(xdbc.out_buf, XDBC_MAX_PACKET, data, size, 0);
503		addr = xdbc.out_dma;
504		xdbc.flags |= XDBC_FLAGS_OUT_PROCESS;
505	}
506
507	xdbc_queue_trb(ring, lower_32_bits(addr), upper_32_bits(addr), length, control);
508
509	/*
510	 * Add a barrier between writes of trb fields and flipping
511	 * the cycle bit:
512	 */
513	wmb();
514	if (cycle)
515		trb->field[3] |= cpu_to_le32(cycle);
516	else
517		trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
518
519	xdbc_ring_doorbell(read ? IN_EP_DOORBELL : OUT_EP_DOORBELL);
520
521	return size;
522}
523
524static int xdbc_handle_external_reset(void)
525{
526	int ret = 0;
527
528	xdbc.flags = 0;
529	writel(0, &xdbc.xdbc_reg->control);
530	ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 10);
531	if (ret)
532		goto reset_out;
533
534	xdbc_mem_init();
535
536	ret = xdbc_start();
537	if (ret < 0)
538		goto reset_out;
539
540	xdbc_trace("dbc recovered\n");
541
542	xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
543
544	xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
545
546	return 0;
547
548reset_out:
549	xdbc_trace("failed to recover from external reset\n");
550	return ret;
551}
552
553static int __init xdbc_early_setup(void)
554{
555	int ret;
556
557	writel(0, &xdbc.xdbc_reg->control);
558	ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 100);
559	if (ret)
560		return ret;
561
562	/* Allocate the table page: */
563	xdbc.table_base = xdbc_get_page(&xdbc.table_dma);
564	if (!xdbc.table_base)
565		return -ENOMEM;
566
567	/* Get and store the transfer buffer: */
568	xdbc.out_buf = xdbc_get_page(&xdbc.out_dma);
569	if (!xdbc.out_buf)
570		return -ENOMEM;
571
572	/* Allocate the event ring: */
573	ret = xdbc_alloc_ring(&xdbc.evt_seg, &xdbc.evt_ring);
574	if (ret < 0)
575		return ret;
576
577	/* Allocate IN/OUT endpoint transfer rings: */
578	ret = xdbc_alloc_ring(&xdbc.in_seg, &xdbc.in_ring);
579	if (ret < 0)
580		return ret;
581
582	ret = xdbc_alloc_ring(&xdbc.out_seg, &xdbc.out_ring);
583	if (ret < 0)
584		return ret;
585
586	xdbc_mem_init();
587
588	ret = xdbc_start();
589	if (ret < 0) {
590		writel(0, &xdbc.xdbc_reg->control);
591		return ret;
592	}
593
594	xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
595
596	xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
597
598	return 0;
599}
600
601int __init early_xdbc_parse_parameter(char *s, int keep_early)
602{
603	unsigned long dbgp_num = 0;
604	u32 bus, dev, func, offset;
605	char *e;
606	int ret;
607
608	if (!early_pci_allowed())
609		return -EPERM;
610
611	early_console_keep = keep_early;
612
613	if (xdbc.xdbc_reg)
614		return 0;
615
616	if (*s) {
617	       dbgp_num = simple_strtoul(s, &e, 10);
618	       if (s == e)
619		       dbgp_num = 0;
620	}
621
622	pr_notice("dbgp_num: %lu\n", dbgp_num);
623
624	/* Locate the host controller: */
625	ret = xdbc_find_dbgp(dbgp_num, &bus, &dev, &func);
626	if (ret) {
627		pr_notice("failed to locate xhci host\n");
628		return -ENODEV;
629	}
630
631	xdbc.vendor	= read_pci_config_16(bus, dev, func, PCI_VENDOR_ID);
632	xdbc.device	= read_pci_config_16(bus, dev, func, PCI_DEVICE_ID);
633	xdbc.bus	= bus;
634	xdbc.dev	= dev;
635	xdbc.func	= func;
636
637	/* Map the IO memory: */
638	xdbc.xhci_base = xdbc_map_pci_mmio(bus, dev, func);
639	if (!xdbc.xhci_base)
640		return -EINVAL;
641
642	/* Locate DbC registers: */
643	offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
644	if (!offset) {
645		pr_notice("xhci host doesn't support debug capability\n");
646		early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
647		xdbc.xhci_base = NULL;
648		xdbc.xhci_length = 0;
649
650		return -ENODEV;
651	}
652	xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
653
654	return 0;
655}
656
657int __init early_xdbc_setup_hardware(void)
658{
659	int ret;
660
661	if (!xdbc.xdbc_reg)
662		return -ENODEV;
663
664	xdbc_bios_handoff();
665
666	raw_spin_lock_init(&xdbc.lock);
667
668	ret = xdbc_early_setup();
669	if (ret) {
670		pr_notice("failed to setup the connection to host\n");
671
672		xdbc_free_ring(&xdbc.evt_ring);
673		xdbc_free_ring(&xdbc.out_ring);
674		xdbc_free_ring(&xdbc.in_ring);
675
676		if (xdbc.table_dma)
677			memblock_phys_free(xdbc.table_dma, PAGE_SIZE);
678
679		if (xdbc.out_dma)
680			memblock_phys_free(xdbc.out_dma, PAGE_SIZE);
681
682		xdbc.table_base = NULL;
683		xdbc.out_buf = NULL;
684	}
685
686	return ret;
687}
688
689static void xdbc_handle_port_status(struct xdbc_trb *evt_trb)
690{
691	u32 port_reg;
692
693	port_reg = readl(&xdbc.xdbc_reg->portsc);
694	if (port_reg & PORTSC_CONN_CHANGE) {
695		xdbc_trace("connect status change event\n");
696
697		/* Check whether cable unplugged: */
698		if (!(port_reg & PORTSC_CONN_STATUS)) {
699			xdbc.flags = 0;
700			xdbc_trace("cable unplugged\n");
701		}
702	}
703
704	if (port_reg & PORTSC_RESET_CHANGE)
705		xdbc_trace("port reset change event\n");
706
707	if (port_reg & PORTSC_LINK_CHANGE)
708		xdbc_trace("port link status change event\n");
709
710	if (port_reg & PORTSC_CONFIG_CHANGE)
711		xdbc_trace("config error change\n");
712
713	/* Write back the value to clear RW1C bits: */
714	writel(port_reg, &xdbc.xdbc_reg->portsc);
715}
716
717static void xdbc_handle_tx_event(struct xdbc_trb *evt_trb)
718{
719	u32 comp_code;
720	int ep_id;
721
722	comp_code	= GET_COMP_CODE(le32_to_cpu(evt_trb->field[2]));
723	ep_id		= TRB_TO_EP_ID(le32_to_cpu(evt_trb->field[3]));
724
725	switch (comp_code) {
726	case COMP_SUCCESS:
727	case COMP_SHORT_PACKET:
728		break;
729	case COMP_TRB_ERROR:
730	case COMP_BABBLE_DETECTED_ERROR:
731	case COMP_USB_TRANSACTION_ERROR:
732	case COMP_STALL_ERROR:
733	default:
734		if (ep_id == XDBC_EPID_OUT || ep_id == XDBC_EPID_OUT_INTEL)
735			xdbc.flags |= XDBC_FLAGS_OUT_STALL;
736		if (ep_id == XDBC_EPID_IN || ep_id == XDBC_EPID_IN_INTEL)
737			xdbc.flags |= XDBC_FLAGS_IN_STALL;
738
739		xdbc_trace("endpoint %d stalled\n", ep_id);
740		break;
741	}
742
743	if (ep_id == XDBC_EPID_IN || ep_id == XDBC_EPID_IN_INTEL) {
744		xdbc.flags &= ~XDBC_FLAGS_IN_PROCESS;
745		xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
746	} else if (ep_id == XDBC_EPID_OUT || ep_id == XDBC_EPID_OUT_INTEL) {
747		xdbc.flags &= ~XDBC_FLAGS_OUT_PROCESS;
748	} else {
749		xdbc_trace("invalid endpoint id %d\n", ep_id);
750	}
751}
752
753static void xdbc_handle_events(void)
754{
755	struct xdbc_trb *evt_trb;
756	bool update_erdp = false;
757	u32 reg;
758	u8 cmd;
759
760	cmd = read_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND);
761	if (!(cmd & PCI_COMMAND_MASTER)) {
762		cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
763		write_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND, cmd);
764	}
765
766	if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
767		return;
768
769	/* Handle external reset events: */
770	reg = readl(&xdbc.xdbc_reg->control);
771	if (!(reg & CTRL_DBC_ENABLE)) {
772		if (xdbc_handle_external_reset()) {
773			xdbc_trace("failed to recover connection\n");
774			return;
775		}
776	}
777
778	/* Handle configure-exit event: */
779	reg = readl(&xdbc.xdbc_reg->control);
780	if (reg & CTRL_DBC_RUN_CHANGE) {
781		writel(reg, &xdbc.xdbc_reg->control);
782		if (reg & CTRL_DBC_RUN)
783			xdbc.flags |= XDBC_FLAGS_CONFIGURED;
784		else
785			xdbc.flags &= ~XDBC_FLAGS_CONFIGURED;
786	}
787
788	/* Handle endpoint stall event: */
789	reg = readl(&xdbc.xdbc_reg->control);
790	if (reg & CTRL_HALT_IN_TR) {
791		xdbc.flags |= XDBC_FLAGS_IN_STALL;
792	} else {
793		xdbc.flags &= ~XDBC_FLAGS_IN_STALL;
794		if (!(xdbc.flags & XDBC_FLAGS_IN_PROCESS))
795			xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
796	}
797
798	if (reg & CTRL_HALT_OUT_TR)
799		xdbc.flags |= XDBC_FLAGS_OUT_STALL;
800	else
801		xdbc.flags &= ~XDBC_FLAGS_OUT_STALL;
802
803	/* Handle the events in the event ring: */
804	evt_trb = xdbc.evt_ring.dequeue;
805	while ((le32_to_cpu(evt_trb->field[3]) & TRB_CYCLE) == xdbc.evt_ring.cycle_state) {
806		/*
807		 * Add a barrier between reading the cycle flag and any
808		 * reads of the event's flags/data below:
809		 */
810		rmb();
811
812		switch ((le32_to_cpu(evt_trb->field[3]) & TRB_TYPE_BITMASK)) {
813		case TRB_TYPE(TRB_PORT_STATUS):
814			xdbc_handle_port_status(evt_trb);
815			break;
816		case TRB_TYPE(TRB_TRANSFER):
817			xdbc_handle_tx_event(evt_trb);
818			break;
819		default:
820			break;
821		}
822
823		++(xdbc.evt_ring.dequeue);
824		if (xdbc.evt_ring.dequeue == &xdbc.evt_seg.trbs[TRBS_PER_SEGMENT]) {
825			xdbc.evt_ring.dequeue = xdbc.evt_seg.trbs;
826			xdbc.evt_ring.cycle_state ^= 1;
827		}
828
829		evt_trb = xdbc.evt_ring.dequeue;
830		update_erdp = true;
831	}
832
833	/* Update event ring dequeue pointer: */
834	if (update_erdp)
835		xdbc_write64(__pa(xdbc.evt_ring.dequeue), &xdbc.xdbc_reg->erdp);
836}
837
838static int xdbc_bulk_write(const char *bytes, int size)
839{
840	int ret, timeout = 0;
841	unsigned long flags;
842
843retry:
844	if (in_nmi()) {
845		if (!raw_spin_trylock_irqsave(&xdbc.lock, flags))
846			return -EAGAIN;
847	} else {
848		raw_spin_lock_irqsave(&xdbc.lock, flags);
849	}
850
851	xdbc_handle_events();
852
853	/* Check completion of the previous request: */
854	if ((xdbc.flags & XDBC_FLAGS_OUT_PROCESS) && (timeout < 2000000)) {
855		raw_spin_unlock_irqrestore(&xdbc.lock, flags);
856		udelay(100);
857		timeout += 100;
858		goto retry;
859	}
860
861	if (xdbc.flags & XDBC_FLAGS_OUT_PROCESS) {
862		raw_spin_unlock_irqrestore(&xdbc.lock, flags);
863		xdbc_trace("previous transfer not completed yet\n");
864
865		return -ETIMEDOUT;
866	}
867
868	ret = xdbc_bulk_transfer((void *)bytes, size, false);
869	raw_spin_unlock_irqrestore(&xdbc.lock, flags);
870
871	return ret;
872}
873
874static void early_xdbc_write(struct console *con, const char *str, u32 n)
875{
876	/* static variables are zeroed, so buf is always NULL terminated */
877	static char buf[XDBC_MAX_PACKET + 1];
878	int chunk, ret;
879	int use_cr = 0;
880
881	if (!xdbc.xdbc_reg)
882		return;
883
884	while (n > 0) {
885		for (chunk = 0; chunk < XDBC_MAX_PACKET && n > 0; str++, chunk++, n--) {
886
887			if (!use_cr && *str == '\n') {
888				use_cr = 1;
889				buf[chunk] = '\r';
890				str--;
891				n++;
892				continue;
893			}
894
895			if (use_cr)
896				use_cr = 0;
897			buf[chunk] = *str;
898		}
899
900		if (chunk > 0) {
901			ret = xdbc_bulk_write(buf, chunk);
902			if (ret < 0)
903				xdbc_trace("missed message {%s}\n", buf);
904		}
905	}
906}
907
908static struct console early_xdbc_console = {
909	.name		= "earlyxdbc",
910	.write		= early_xdbc_write,
911	.flags		= CON_PRINTBUFFER,
912	.index		= -1,
913};
914
915void __init early_xdbc_register_console(void)
916{
917	if (early_console)
918		return;
919
920	early_console = &early_xdbc_console;
921	if (early_console_keep)
922		early_console->flags &= ~CON_BOOT;
923	else
924		early_console->flags |= CON_BOOT;
925	register_console(early_console);
926}
927
928static void xdbc_unregister_console(void)
929{
930	if (console_is_registered(&early_xdbc_console))
931		unregister_console(&early_xdbc_console);
932}
933
934static int xdbc_scrub_function(void *ptr)
935{
936	unsigned long flags;
937
938	while (true) {
939		raw_spin_lock_irqsave(&xdbc.lock, flags);
940		xdbc_handle_events();
941
942		if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED)) {
943			raw_spin_unlock_irqrestore(&xdbc.lock, flags);
944			break;
945		}
946
947		raw_spin_unlock_irqrestore(&xdbc.lock, flags);
948		schedule_timeout_interruptible(1);
949	}
950
951	xdbc_unregister_console();
952	writel(0, &xdbc.xdbc_reg->control);
953	xdbc_trace("dbc scrub function exits\n");
954
955	return 0;
956}
957
958static int __init xdbc_init(void)
959{
960	unsigned long flags;
961	void __iomem *base;
962	int ret = 0;
963	u32 offset;
964
965	if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
966		return 0;
967
968	/*
969	 * It's time to shut down the DbC, so that the debug
970	 * port can be reused by the host controller:
971	 */
972	if (early_xdbc_console.index == -1 ||
973	    (early_xdbc_console.flags & CON_BOOT)) {
974		xdbc_trace("hardware not used anymore\n");
975		goto free_and_quit;
976	}
977
978	base = ioremap(xdbc.xhci_start, xdbc.xhci_length);
979	if (!base) {
980		xdbc_trace("failed to remap the io address\n");
981		ret = -ENOMEM;
982		goto free_and_quit;
983	}
984
985	raw_spin_lock_irqsave(&xdbc.lock, flags);
986	early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
987	xdbc.xhci_base = base;
988	offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
989	xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
990	raw_spin_unlock_irqrestore(&xdbc.lock, flags);
991
992	kthread_run(xdbc_scrub_function, NULL, "%s", "xdbc");
993
994	return 0;
995
996free_and_quit:
997	xdbc_free_ring(&xdbc.evt_ring);
998	xdbc_free_ring(&xdbc.out_ring);
999	xdbc_free_ring(&xdbc.in_ring);
1000	memblock_phys_free(xdbc.table_dma, PAGE_SIZE);
1001	memblock_phys_free(xdbc.out_dma, PAGE_SIZE);
1002	writel(0, &xdbc.xdbc_reg->control);
1003	early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
1004
1005	return ret;
1006}
1007subsys_initcall(xdbc_init);
1008