Merge tag 'acpi-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
[muen/linux.git] / drivers / usb / host / xhci-dbgcap.c
1 // SPDX-License-Identifier: GPL-2.0
2 /**
3  * xhci-dbgcap.c - xHCI debug capability support
4  *
5  * Copyright (C) 2017 Intel Corporation
6  *
7  * Author: Lu Baolu <baolu.lu@linux.intel.com>
8  */
9 #include <linux/dma-mapping.h>
10 #include <linux/slab.h>
11 #include <linux/nls.h>
12
13 #include "xhci.h"
14 #include "xhci-trace.h"
15 #include "xhci-dbgcap.h"
16
17 static inline void *
18 dbc_dma_alloc_coherent(struct xhci_hcd *xhci, size_t size,
19                        dma_addr_t *dma_handle, gfp_t flags)
20 {
21         void            *vaddr;
22
23         vaddr = dma_alloc_coherent(xhci_to_hcd(xhci)->self.sysdev,
24                                    size, dma_handle, flags);
25         memset(vaddr, 0, size);
26         return vaddr;
27 }
28
29 static inline void
30 dbc_dma_free_coherent(struct xhci_hcd *xhci, size_t size,
31                       void *cpu_addr, dma_addr_t dma_handle)
32 {
33         if (cpu_addr)
34                 dma_free_coherent(xhci_to_hcd(xhci)->self.sysdev,
35                                   size, cpu_addr, dma_handle);
36 }
37
38 static u32 xhci_dbc_populate_strings(struct dbc_str_descs *strings)
39 {
40         struct usb_string_descriptor    *s_desc;
41         u32                             string_length;
42
43         /* Serial string: */
44         s_desc = (struct usb_string_descriptor *)strings->serial;
45         utf8s_to_utf16s(DBC_STRING_SERIAL, strlen(DBC_STRING_SERIAL),
46                         UTF16_LITTLE_ENDIAN, (wchar_t *)s_desc->wData,
47                         DBC_MAX_STRING_LENGTH);
48
49         s_desc->bLength         = (strlen(DBC_STRING_SERIAL) + 1) * 2;
50         s_desc->bDescriptorType = USB_DT_STRING;
51         string_length           = s_desc->bLength;
52         string_length           <<= 8;
53
54         /* Product string: */
55         s_desc = (struct usb_string_descriptor *)strings->product;
56         utf8s_to_utf16s(DBC_STRING_PRODUCT, strlen(DBC_STRING_PRODUCT),
57                         UTF16_LITTLE_ENDIAN, (wchar_t *)s_desc->wData,
58                         DBC_MAX_STRING_LENGTH);
59
60         s_desc->bLength         = (strlen(DBC_STRING_PRODUCT) + 1) * 2;
61         s_desc->bDescriptorType = USB_DT_STRING;
62         string_length           += s_desc->bLength;
63         string_length           <<= 8;
64
65         /* Manufacture string: */
66         s_desc = (struct usb_string_descriptor *)strings->manufacturer;
67         utf8s_to_utf16s(DBC_STRING_MANUFACTURER,
68                         strlen(DBC_STRING_MANUFACTURER),
69                         UTF16_LITTLE_ENDIAN, (wchar_t *)s_desc->wData,
70                         DBC_MAX_STRING_LENGTH);
71
72         s_desc->bLength         = (strlen(DBC_STRING_MANUFACTURER) + 1) * 2;
73         s_desc->bDescriptorType = USB_DT_STRING;
74         string_length           += s_desc->bLength;
75         string_length           <<= 8;
76
77         /* String0: */
78         strings->string0[0]     = 4;
79         strings->string0[1]     = USB_DT_STRING;
80         strings->string0[2]     = 0x09;
81         strings->string0[3]     = 0x04;
82         string_length           += 4;
83
84         return string_length;
85 }
86
87 static void xhci_dbc_init_contexts(struct xhci_hcd *xhci, u32 string_length)
88 {
89         struct xhci_dbc         *dbc;
90         struct dbc_info_context *info;
91         struct xhci_ep_ctx      *ep_ctx;
92         u32                     dev_info;
93         dma_addr_t              deq, dma;
94         unsigned int            max_burst;
95
96         dbc = xhci->dbc;
97         if (!dbc)
98                 return;
99
100         /* Populate info Context: */
101         info                    = (struct dbc_info_context *)dbc->ctx->bytes;
102         dma                     = dbc->string_dma;
103         info->string0           = cpu_to_le64(dma);
104         info->manufacturer      = cpu_to_le64(dma + DBC_MAX_STRING_LENGTH);
105         info->product           = cpu_to_le64(dma + DBC_MAX_STRING_LENGTH * 2);
106         info->serial            = cpu_to_le64(dma + DBC_MAX_STRING_LENGTH * 3);
107         info->length            = cpu_to_le32(string_length);
108
109         /* Populate bulk out endpoint context: */
110         ep_ctx                  = dbc_bulkout_ctx(dbc);
111         max_burst               = DBC_CTRL_MAXBURST(readl(&dbc->regs->control));
112         deq                     = dbc_bulkout_enq(dbc);
113         ep_ctx->ep_info         = 0;
114         ep_ctx->ep_info2        = dbc_epctx_info2(BULK_OUT_EP, 1024, max_burst);
115         ep_ctx->deq             = cpu_to_le64(deq | dbc->ring_out->cycle_state);
116
117         /* Populate bulk in endpoint context: */
118         ep_ctx                  = dbc_bulkin_ctx(dbc);
119         deq                     = dbc_bulkin_enq(dbc);
120         ep_ctx->ep_info         = 0;
121         ep_ctx->ep_info2        = dbc_epctx_info2(BULK_IN_EP, 1024, max_burst);
122         ep_ctx->deq             = cpu_to_le64(deq | dbc->ring_in->cycle_state);
123
124         /* Set DbC context and info registers: */
125         xhci_write_64(xhci, dbc->ctx->dma, &dbc->regs->dccp);
126
127         dev_info = cpu_to_le32((DBC_VENDOR_ID << 16) | DBC_PROTOCOL);
128         writel(dev_info, &dbc->regs->devinfo1);
129
130         dev_info = cpu_to_le32((DBC_DEVICE_REV << 16) | DBC_PRODUCT_ID);
131         writel(dev_info, &dbc->regs->devinfo2);
132 }
133
134 static void xhci_dbc_giveback(struct dbc_request *req, int status)
135         __releases(&dbc->lock)
136         __acquires(&dbc->lock)
137 {
138         struct dbc_ep           *dep = req->dep;
139         struct xhci_dbc         *dbc = dep->dbc;
140         struct xhci_hcd         *xhci = dbc->xhci;
141         struct device           *dev = xhci_to_hcd(dbc->xhci)->self.sysdev;
142
143         list_del_init(&req->list_pending);
144         req->trb_dma = 0;
145         req->trb = NULL;
146
147         if (req->status == -EINPROGRESS)
148                 req->status = status;
149
150         trace_xhci_dbc_giveback_request(req);
151
152         dma_unmap_single(dev,
153                          req->dma,
154                          req->length,
155                          dbc_ep_dma_direction(dep));
156
157         /* Give back the transfer request: */
158         spin_unlock(&dbc->lock);
159         req->complete(xhci, req);
160         spin_lock(&dbc->lock);
161 }
162
163 static void xhci_dbc_flush_single_request(struct dbc_request *req)
164 {
165         union xhci_trb  *trb = req->trb;
166
167         trb->generic.field[0]   = 0;
168         trb->generic.field[1]   = 0;
169         trb->generic.field[2]   = 0;
170         trb->generic.field[3]   &= cpu_to_le32(TRB_CYCLE);
171         trb->generic.field[3]   |= cpu_to_le32(TRB_TYPE(TRB_TR_NOOP));
172
173         xhci_dbc_giveback(req, -ESHUTDOWN);
174 }
175
176 static void xhci_dbc_flush_endpoint_requests(struct dbc_ep *dep)
177 {
178         struct dbc_request      *req, *tmp;
179
180         list_for_each_entry_safe(req, tmp, &dep->list_pending, list_pending)
181                 xhci_dbc_flush_single_request(req);
182 }
183
184 static void xhci_dbc_flush_requests(struct xhci_dbc *dbc)
185 {
186         xhci_dbc_flush_endpoint_requests(&dbc->eps[BULK_OUT]);
187         xhci_dbc_flush_endpoint_requests(&dbc->eps[BULK_IN]);
188 }
189
190 struct dbc_request *
191 dbc_alloc_request(struct dbc_ep *dep, gfp_t gfp_flags)
192 {
193         struct dbc_request      *req;
194
195         req = kzalloc(sizeof(*req), gfp_flags);
196         if (!req)
197                 return NULL;
198
199         req->dep = dep;
200         INIT_LIST_HEAD(&req->list_pending);
201         INIT_LIST_HEAD(&req->list_pool);
202         req->direction = dep->direction;
203
204         trace_xhci_dbc_alloc_request(req);
205
206         return req;
207 }
208
209 void
210 dbc_free_request(struct dbc_ep *dep, struct dbc_request *req)
211 {
212         trace_xhci_dbc_free_request(req);
213
214         kfree(req);
215 }
216
217 static void
218 xhci_dbc_queue_trb(struct xhci_ring *ring, u32 field1,
219                    u32 field2, u32 field3, u32 field4)
220 {
221         union xhci_trb          *trb, *next;
222
223         trb = ring->enqueue;
224         trb->generic.field[0]   = cpu_to_le32(field1);
225         trb->generic.field[1]   = cpu_to_le32(field2);
226         trb->generic.field[2]   = cpu_to_le32(field3);
227         trb->generic.field[3]   = cpu_to_le32(field4);
228
229         trace_xhci_dbc_gadget_ep_queue(ring, &trb->generic);
230
231         ring->num_trbs_free--;
232         next = ++(ring->enqueue);
233         if (TRB_TYPE_LINK_LE32(next->link.control)) {
234                 next->link.control ^= cpu_to_le32(TRB_CYCLE);
235                 ring->enqueue = ring->enq_seg->trbs;
236                 ring->cycle_state ^= 1;
237         }
238 }
239
240 static int xhci_dbc_queue_bulk_tx(struct dbc_ep *dep,
241                                   struct dbc_request *req)
242 {
243         u64                     addr;
244         union xhci_trb          *trb;
245         unsigned int            num_trbs;
246         struct xhci_dbc         *dbc = dep->dbc;
247         struct xhci_ring        *ring = dep->ring;
248         u32                     length, control, cycle;
249
250         num_trbs = count_trbs(req->dma, req->length);
251         WARN_ON(num_trbs != 1);
252         if (ring->num_trbs_free < num_trbs)
253                 return -EBUSY;
254
255         addr    = req->dma;
256         trb     = ring->enqueue;
257         cycle   = ring->cycle_state;
258         length  = TRB_LEN(req->length);
259         control = TRB_TYPE(TRB_NORMAL) | TRB_IOC;
260
261         if (cycle)
262                 control &= cpu_to_le32(~TRB_CYCLE);
263         else
264                 control |= cpu_to_le32(TRB_CYCLE);
265
266         req->trb = ring->enqueue;
267         req->trb_dma = xhci_trb_virt_to_dma(ring->enq_seg, ring->enqueue);
268         xhci_dbc_queue_trb(ring,
269                            lower_32_bits(addr),
270                            upper_32_bits(addr),
271                            length, control);
272
273         /*
274          * Add a barrier between writes of trb fields and flipping
275          * the cycle bit:
276          */
277         wmb();
278
279         if (cycle)
280                 trb->generic.field[3] |= cpu_to_le32(TRB_CYCLE);
281         else
282                 trb->generic.field[3] &= cpu_to_le32(~TRB_CYCLE);
283
284         writel(DBC_DOOR_BELL_TARGET(dep->direction), &dbc->regs->doorbell);
285
286         return 0;
287 }
288
289 static int
290 dbc_ep_do_queue(struct dbc_ep *dep, struct dbc_request *req)
291 {
292         int                     ret;
293         struct device           *dev;
294         struct xhci_dbc         *dbc = dep->dbc;
295         struct xhci_hcd         *xhci = dbc->xhci;
296
297         dev = xhci_to_hcd(xhci)->self.sysdev;
298
299         if (!req->length || !req->buf)
300                 return -EINVAL;
301
302         req->actual             = 0;
303         req->status             = -EINPROGRESS;
304
305         req->dma = dma_map_single(dev,
306                                   req->buf,
307                                   req->length,
308                                   dbc_ep_dma_direction(dep));
309         if (dma_mapping_error(dev, req->dma)) {
310                 xhci_err(xhci, "failed to map buffer\n");
311                 return -EFAULT;
312         }
313
314         ret = xhci_dbc_queue_bulk_tx(dep, req);
315         if (ret) {
316                 xhci_err(xhci, "failed to queue trbs\n");
317                 dma_unmap_single(dev,
318                                  req->dma,
319                                  req->length,
320                                  dbc_ep_dma_direction(dep));
321                 return -EFAULT;
322         }
323
324         list_add_tail(&req->list_pending, &dep->list_pending);
325
326         return 0;
327 }
328
329 int dbc_ep_queue(struct dbc_ep *dep, struct dbc_request *req,
330                  gfp_t gfp_flags)
331 {
332         unsigned long           flags;
333         struct xhci_dbc         *dbc = dep->dbc;
334         int                     ret = -ESHUTDOWN;
335
336         spin_lock_irqsave(&dbc->lock, flags);
337         if (dbc->state == DS_CONFIGURED)
338                 ret = dbc_ep_do_queue(dep, req);
339         spin_unlock_irqrestore(&dbc->lock, flags);
340
341         mod_delayed_work(system_wq, &dbc->event_work, 0);
342
343         trace_xhci_dbc_queue_request(req);
344
345         return ret;
346 }
347
348 static inline void xhci_dbc_do_eps_init(struct xhci_hcd *xhci, bool direction)
349 {
350         struct dbc_ep           *dep;
351         struct xhci_dbc         *dbc = xhci->dbc;
352
353         dep                     = &dbc->eps[direction];
354         dep->dbc                = dbc;
355         dep->direction          = direction;
356         dep->ring               = direction ? dbc->ring_in : dbc->ring_out;
357
358         INIT_LIST_HEAD(&dep->list_pending);
359 }
360
361 static void xhci_dbc_eps_init(struct xhci_hcd *xhci)
362 {
363         xhci_dbc_do_eps_init(xhci, BULK_OUT);
364         xhci_dbc_do_eps_init(xhci, BULK_IN);
365 }
366
367 static void xhci_dbc_eps_exit(struct xhci_hcd *xhci)
368 {
369         struct xhci_dbc         *dbc = xhci->dbc;
370
371         memset(dbc->eps, 0, sizeof(struct dbc_ep) * ARRAY_SIZE(dbc->eps));
372 }
373
374 static int xhci_dbc_mem_init(struct xhci_hcd *xhci, gfp_t flags)
375 {
376         int                     ret;
377         dma_addr_t              deq;
378         u32                     string_length;
379         struct xhci_dbc         *dbc = xhci->dbc;
380
381         /* Allocate various rings for events and transfers: */
382         dbc->ring_evt = xhci_ring_alloc(xhci, 1, 1, TYPE_EVENT, 0, flags);
383         if (!dbc->ring_evt)
384                 goto evt_fail;
385
386         dbc->ring_in = xhci_ring_alloc(xhci, 1, 1, TYPE_BULK, 0, flags);
387         if (!dbc->ring_in)
388                 goto in_fail;
389
390         dbc->ring_out = xhci_ring_alloc(xhci, 1, 1, TYPE_BULK, 0, flags);
391         if (!dbc->ring_out)
392                 goto out_fail;
393
394         /* Allocate and populate ERST: */
395         ret = xhci_alloc_erst(xhci, dbc->ring_evt, &dbc->erst, flags);
396         if (ret)
397                 goto erst_fail;
398
399         /* Allocate context data structure: */
400         dbc->ctx = xhci_alloc_container_ctx(xhci, XHCI_CTX_TYPE_DEVICE, flags);
401         if (!dbc->ctx)
402                 goto ctx_fail;
403
404         /* Allocate the string table: */
405         dbc->string_size = sizeof(struct dbc_str_descs);
406         dbc->string = dbc_dma_alloc_coherent(xhci,
407                                              dbc->string_size,
408                                              &dbc->string_dma,
409                                              flags);
410         if (!dbc->string)
411                 goto string_fail;
412
413         /* Setup ERST register: */
414         writel(dbc->erst.erst_size, &dbc->regs->ersts);
415         xhci_write_64(xhci, dbc->erst.erst_dma_addr, &dbc->regs->erstba);
416         deq = xhci_trb_virt_to_dma(dbc->ring_evt->deq_seg,
417                                    dbc->ring_evt->dequeue);
418         xhci_write_64(xhci, deq, &dbc->regs->erdp);
419
420         /* Setup strings and contexts: */
421         string_length = xhci_dbc_populate_strings(dbc->string);
422         xhci_dbc_init_contexts(xhci, string_length);
423
424         mmiowb();
425
426         xhci_dbc_eps_init(xhci);
427         dbc->state = DS_INITIALIZED;
428
429         return 0;
430
431 string_fail:
432         xhci_free_container_ctx(xhci, dbc->ctx);
433         dbc->ctx = NULL;
434 ctx_fail:
435         xhci_free_erst(xhci, &dbc->erst);
436 erst_fail:
437         xhci_ring_free(xhci, dbc->ring_out);
438         dbc->ring_out = NULL;
439 out_fail:
440         xhci_ring_free(xhci, dbc->ring_in);
441         dbc->ring_in = NULL;
442 in_fail:
443         xhci_ring_free(xhci, dbc->ring_evt);
444         dbc->ring_evt = NULL;
445 evt_fail:
446         return -ENOMEM;
447 }
448
449 static void xhci_dbc_mem_cleanup(struct xhci_hcd *xhci)
450 {
451         struct xhci_dbc         *dbc = xhci->dbc;
452
453         if (!dbc)
454                 return;
455
456         xhci_dbc_eps_exit(xhci);
457
458         if (dbc->string) {
459                 dbc_dma_free_coherent(xhci,
460                                       dbc->string_size,
461                                       dbc->string, dbc->string_dma);
462                 dbc->string = NULL;
463         }
464
465         xhci_free_container_ctx(xhci, dbc->ctx);
466         dbc->ctx = NULL;
467
468         xhci_free_erst(xhci, &dbc->erst);
469         xhci_ring_free(xhci, dbc->ring_out);
470         xhci_ring_free(xhci, dbc->ring_in);
471         xhci_ring_free(xhci, dbc->ring_evt);
472         dbc->ring_in = NULL;
473         dbc->ring_out = NULL;
474         dbc->ring_evt = NULL;
475 }
476
477 static int xhci_do_dbc_start(struct xhci_hcd *xhci)
478 {
479         int                     ret;
480         u32                     ctrl;
481         struct xhci_dbc         *dbc = xhci->dbc;
482
483         if (dbc->state != DS_DISABLED)
484                 return -EINVAL;
485
486         writel(0, &dbc->regs->control);
487         ret = xhci_handshake(&dbc->regs->control,
488                              DBC_CTRL_DBC_ENABLE,
489                              0, 1000);
490         if (ret)
491                 return ret;
492
493         ret = xhci_dbc_mem_init(xhci, GFP_ATOMIC);
494         if (ret)
495                 return ret;
496
497         ctrl = readl(&dbc->regs->control);
498         writel(ctrl | DBC_CTRL_DBC_ENABLE | DBC_CTRL_PORT_ENABLE,
499                &dbc->regs->control);
500         ret = xhci_handshake(&dbc->regs->control,
501                              DBC_CTRL_DBC_ENABLE,
502                              DBC_CTRL_DBC_ENABLE, 1000);
503         if (ret)
504                 return ret;
505
506         dbc->state = DS_ENABLED;
507
508         return 0;
509 }
510
511 static int xhci_do_dbc_stop(struct xhci_hcd *xhci)
512 {
513         struct xhci_dbc         *dbc = xhci->dbc;
514
515         if (dbc->state == DS_DISABLED)
516                 return -1;
517
518         writel(0, &dbc->regs->control);
519         xhci_dbc_mem_cleanup(xhci);
520         dbc->state = DS_DISABLED;
521
522         return 0;
523 }
524
525 static int xhci_dbc_start(struct xhci_hcd *xhci)
526 {
527         int                     ret;
528         unsigned long           flags;
529         struct xhci_dbc         *dbc = xhci->dbc;
530
531         WARN_ON(!dbc);
532
533         pm_runtime_get_sync(xhci_to_hcd(xhci)->self.controller);
534
535         spin_lock_irqsave(&dbc->lock, flags);
536         ret = xhci_do_dbc_start(xhci);
537         spin_unlock_irqrestore(&dbc->lock, flags);
538
539         if (ret) {
540                 pm_runtime_put(xhci_to_hcd(xhci)->self.controller);
541                 return ret;
542         }
543
544         return mod_delayed_work(system_wq, &dbc->event_work, 1);
545 }
546
547 static void xhci_dbc_stop(struct xhci_hcd *xhci)
548 {
549         int ret;
550         unsigned long           flags;
551         struct xhci_dbc         *dbc = xhci->dbc;
552         struct dbc_port         *port = &dbc->port;
553
554         WARN_ON(!dbc);
555
556         cancel_delayed_work_sync(&dbc->event_work);
557
558         if (port->registered)
559                 xhci_dbc_tty_unregister_device(xhci);
560
561         spin_lock_irqsave(&dbc->lock, flags);
562         ret = xhci_do_dbc_stop(xhci);
563         spin_unlock_irqrestore(&dbc->lock, flags);
564
565         if (!ret)
566                 pm_runtime_put_sync(xhci_to_hcd(xhci)->self.controller);
567 }
568
569 static void
570 dbc_handle_port_status(struct xhci_hcd *xhci, union xhci_trb *event)
571 {
572         u32                     portsc;
573         struct xhci_dbc         *dbc = xhci->dbc;
574
575         portsc = readl(&dbc->regs->portsc);
576         if (portsc & DBC_PORTSC_CONN_CHANGE)
577                 xhci_info(xhci, "DbC port connect change\n");
578
579         if (portsc & DBC_PORTSC_RESET_CHANGE)
580                 xhci_info(xhci, "DbC port reset change\n");
581
582         if (portsc & DBC_PORTSC_LINK_CHANGE)
583                 xhci_info(xhci, "DbC port link status change\n");
584
585         if (portsc & DBC_PORTSC_CONFIG_CHANGE)
586                 xhci_info(xhci, "DbC config error change\n");
587
588         /* Port reset change bit will be cleared in other place: */
589         writel(portsc & ~DBC_PORTSC_RESET_CHANGE, &dbc->regs->portsc);
590 }
591
592 static void dbc_handle_xfer_event(struct xhci_hcd *xhci, union xhci_trb *event)
593 {
594         struct dbc_ep           *dep;
595         struct xhci_ring        *ring;
596         int                     ep_id;
597         int                     status;
598         u32                     comp_code;
599         size_t                  remain_length;
600         struct dbc_request      *req = NULL, *r;
601
602         comp_code       = GET_COMP_CODE(le32_to_cpu(event->generic.field[2]));
603         remain_length   = EVENT_TRB_LEN(le32_to_cpu(event->generic.field[2]));
604         ep_id           = TRB_TO_EP_ID(le32_to_cpu(event->generic.field[3]));
605         dep             = (ep_id == EPID_OUT) ?
606                                 get_out_ep(xhci) : get_in_ep(xhci);
607         ring            = dep->ring;
608
609         switch (comp_code) {
610         case COMP_SUCCESS:
611                 remain_length = 0;
612         /* FALLTHROUGH */
613         case COMP_SHORT_PACKET:
614                 status = 0;
615                 break;
616         case COMP_TRB_ERROR:
617         case COMP_BABBLE_DETECTED_ERROR:
618         case COMP_USB_TRANSACTION_ERROR:
619         case COMP_STALL_ERROR:
620                 xhci_warn(xhci, "tx error %d detected\n", comp_code);
621                 status = -comp_code;
622                 break;
623         default:
624                 xhci_err(xhci, "unknown tx error %d\n", comp_code);
625                 status = -comp_code;
626                 break;
627         }
628
629         /* Match the pending request: */
630         list_for_each_entry(r, &dep->list_pending, list_pending) {
631                 if (r->trb_dma == event->trans_event.buffer) {
632                         req = r;
633                         break;
634                 }
635         }
636
637         if (!req) {
638                 xhci_warn(xhci, "no matched request\n");
639                 return;
640         }
641
642         trace_xhci_dbc_handle_transfer(ring, &req->trb->generic);
643
644         ring->num_trbs_free++;
645         req->actual = req->length - remain_length;
646         xhci_dbc_giveback(req, status);
647 }
648
649 static enum evtreturn xhci_dbc_do_handle_events(struct xhci_dbc *dbc)
650 {
651         dma_addr_t              deq;
652         struct dbc_ep           *dep;
653         union xhci_trb          *evt;
654         u32                     ctrl, portsc;
655         struct xhci_hcd         *xhci = dbc->xhci;
656         bool                    update_erdp = false;
657
658         /* DbC state machine: */
659         switch (dbc->state) {
660         case DS_DISABLED:
661         case DS_INITIALIZED:
662
663                 return EVT_ERR;
664         case DS_ENABLED:
665                 portsc = readl(&dbc->regs->portsc);
666                 if (portsc & DBC_PORTSC_CONN_STATUS) {
667                         dbc->state = DS_CONNECTED;
668                         xhci_info(xhci, "DbC connected\n");
669                 }
670
671                 return EVT_DONE;
672         case DS_CONNECTED:
673                 ctrl = readl(&dbc->regs->control);
674                 if (ctrl & DBC_CTRL_DBC_RUN) {
675                         dbc->state = DS_CONFIGURED;
676                         xhci_info(xhci, "DbC configured\n");
677                         portsc = readl(&dbc->regs->portsc);
678                         writel(portsc, &dbc->regs->portsc);
679                         return EVT_GSER;
680                 }
681
682                 return EVT_DONE;
683         case DS_CONFIGURED:
684                 /* Handle cable unplug event: */
685                 portsc = readl(&dbc->regs->portsc);
686                 if (!(portsc & DBC_PORTSC_PORT_ENABLED) &&
687                     !(portsc & DBC_PORTSC_CONN_STATUS)) {
688                         xhci_info(xhci, "DbC cable unplugged\n");
689                         dbc->state = DS_ENABLED;
690                         xhci_dbc_flush_requests(dbc);
691
692                         return EVT_DISC;
693                 }
694
695                 /* Handle debug port reset event: */
696                 if (portsc & DBC_PORTSC_RESET_CHANGE) {
697                         xhci_info(xhci, "DbC port reset\n");
698                         writel(portsc, &dbc->regs->portsc);
699                         dbc->state = DS_ENABLED;
700                         xhci_dbc_flush_requests(dbc);
701
702                         return EVT_DISC;
703                 }
704
705                 /* Handle endpoint stall event: */
706                 ctrl = readl(&dbc->regs->control);
707                 if ((ctrl & DBC_CTRL_HALT_IN_TR) ||
708                     (ctrl & DBC_CTRL_HALT_OUT_TR)) {
709                         xhci_info(xhci, "DbC Endpoint stall\n");
710                         dbc->state = DS_STALLED;
711
712                         if (ctrl & DBC_CTRL_HALT_IN_TR) {
713                                 dep = get_in_ep(xhci);
714                                 xhci_dbc_flush_endpoint_requests(dep);
715                         }
716
717                         if (ctrl & DBC_CTRL_HALT_OUT_TR) {
718                                 dep = get_out_ep(xhci);
719                                 xhci_dbc_flush_endpoint_requests(dep);
720                         }
721
722                         return EVT_DONE;
723                 }
724
725                 /* Clear DbC run change bit: */
726                 if (ctrl & DBC_CTRL_DBC_RUN_CHANGE) {
727                         writel(ctrl, &dbc->regs->control);
728                         ctrl = readl(&dbc->regs->control);
729                 }
730
731                 break;
732         case DS_STALLED:
733                 ctrl = readl(&dbc->regs->control);
734                 if (!(ctrl & DBC_CTRL_HALT_IN_TR) &&
735                     !(ctrl & DBC_CTRL_HALT_OUT_TR) &&
736                     (ctrl & DBC_CTRL_DBC_RUN)) {
737                         dbc->state = DS_CONFIGURED;
738                         break;
739                 }
740
741                 return EVT_DONE;
742         default:
743                 xhci_err(xhci, "Unknown DbC state %d\n", dbc->state);
744                 break;
745         }
746
747         /* Handle the events in the event ring: */
748         evt = dbc->ring_evt->dequeue;
749         while ((le32_to_cpu(evt->event_cmd.flags) & TRB_CYCLE) ==
750                         dbc->ring_evt->cycle_state) {
751                 /*
752                  * Add a barrier between reading the cycle flag and any
753                  * reads of the event's flags/data below:
754                  */
755                 rmb();
756
757                 trace_xhci_dbc_handle_event(dbc->ring_evt, &evt->generic);
758
759                 switch (le32_to_cpu(evt->event_cmd.flags) & TRB_TYPE_BITMASK) {
760                 case TRB_TYPE(TRB_PORT_STATUS):
761                         dbc_handle_port_status(xhci, evt);
762                         break;
763                 case TRB_TYPE(TRB_TRANSFER):
764                         dbc_handle_xfer_event(xhci, evt);
765                         break;
766                 default:
767                         break;
768                 }
769
770                 inc_deq(xhci, dbc->ring_evt);
771                 evt = dbc->ring_evt->dequeue;
772                 update_erdp = true;
773         }
774
775         /* Update event ring dequeue pointer: */
776         if (update_erdp) {
777                 deq = xhci_trb_virt_to_dma(dbc->ring_evt->deq_seg,
778                                            dbc->ring_evt->dequeue);
779                 xhci_write_64(xhci, deq, &dbc->regs->erdp);
780         }
781
782         return EVT_DONE;
783 }
784
785 static void xhci_dbc_handle_events(struct work_struct *work)
786 {
787         int                     ret;
788         enum evtreturn          evtr;
789         struct xhci_dbc         *dbc;
790         unsigned long           flags;
791         struct xhci_hcd         *xhci;
792
793         dbc = container_of(to_delayed_work(work), struct xhci_dbc, event_work);
794         xhci = dbc->xhci;
795
796         spin_lock_irqsave(&dbc->lock, flags);
797         evtr = xhci_dbc_do_handle_events(dbc);
798         spin_unlock_irqrestore(&dbc->lock, flags);
799
800         switch (evtr) {
801         case EVT_GSER:
802                 ret = xhci_dbc_tty_register_device(xhci);
803                 if (ret) {
804                         xhci_err(xhci, "failed to alloc tty device\n");
805                         break;
806                 }
807
808                 xhci_info(xhci, "DbC now attached to /dev/ttyDBC0\n");
809                 break;
810         case EVT_DISC:
811                 xhci_dbc_tty_unregister_device(xhci);
812                 break;
813         case EVT_DONE:
814                 break;
815         default:
816                 xhci_info(xhci, "stop handling dbc events\n");
817                 return;
818         }
819
820         mod_delayed_work(system_wq, &dbc->event_work, 1);
821 }
822
823 static void xhci_do_dbc_exit(struct xhci_hcd *xhci)
824 {
825         unsigned long           flags;
826
827         spin_lock_irqsave(&xhci->lock, flags);
828         kfree(xhci->dbc);
829         xhci->dbc = NULL;
830         spin_unlock_irqrestore(&xhci->lock, flags);
831 }
832
833 static int xhci_do_dbc_init(struct xhci_hcd *xhci)
834 {
835         u32                     reg;
836         struct xhci_dbc         *dbc;
837         unsigned long           flags;
838         void __iomem            *base;
839         int                     dbc_cap_offs;
840
841         base = &xhci->cap_regs->hc_capbase;
842         dbc_cap_offs = xhci_find_next_ext_cap(base, 0, XHCI_EXT_CAPS_DEBUG);
843         if (!dbc_cap_offs)
844                 return -ENODEV;
845
846         dbc = kzalloc(sizeof(*dbc), GFP_KERNEL);
847         if (!dbc)
848                 return -ENOMEM;
849
850         dbc->regs = base + dbc_cap_offs;
851
852         /* We will avoid using DbC in xhci driver if it's in use. */
853         reg = readl(&dbc->regs->control);
854         if (reg & DBC_CTRL_DBC_ENABLE) {
855                 kfree(dbc);
856                 return -EBUSY;
857         }
858
859         spin_lock_irqsave(&xhci->lock, flags);
860         if (xhci->dbc) {
861                 spin_unlock_irqrestore(&xhci->lock, flags);
862                 kfree(dbc);
863                 return -EBUSY;
864         }
865         xhci->dbc = dbc;
866         spin_unlock_irqrestore(&xhci->lock, flags);
867
868         dbc->xhci = xhci;
869         INIT_DELAYED_WORK(&dbc->event_work, xhci_dbc_handle_events);
870         spin_lock_init(&dbc->lock);
871
872         return 0;
873 }
874
875 static ssize_t dbc_show(struct device *dev,
876                         struct device_attribute *attr,
877                         char *buf)
878 {
879         const char              *p;
880         struct xhci_dbc         *dbc;
881         struct xhci_hcd         *xhci;
882
883         xhci = hcd_to_xhci(dev_get_drvdata(dev));
884         dbc = xhci->dbc;
885
886         switch (dbc->state) {
887         case DS_DISABLED:
888                 p = "disabled";
889                 break;
890         case DS_INITIALIZED:
891                 p = "initialized";
892                 break;
893         case DS_ENABLED:
894                 p = "enabled";
895                 break;
896         case DS_CONNECTED:
897                 p = "connected";
898                 break;
899         case DS_CONFIGURED:
900                 p = "configured";
901                 break;
902         case DS_STALLED:
903                 p = "stalled";
904                 break;
905         default:
906                 p = "unknown";
907         }
908
909         return sprintf(buf, "%s\n", p);
910 }
911
912 static ssize_t dbc_store(struct device *dev,
913                          struct device_attribute *attr,
914                          const char *buf, size_t count)
915 {
916         struct xhci_hcd         *xhci;
917
918         xhci = hcd_to_xhci(dev_get_drvdata(dev));
919
920         if (!strncmp(buf, "enable", 6))
921                 xhci_dbc_start(xhci);
922         else if (!strncmp(buf, "disable", 7))
923                 xhci_dbc_stop(xhci);
924         else
925                 return -EINVAL;
926
927         return count;
928 }
929
930 static DEVICE_ATTR_RW(dbc);
931
932 int xhci_dbc_init(struct xhci_hcd *xhci)
933 {
934         int                     ret;
935         struct device           *dev = xhci_to_hcd(xhci)->self.controller;
936
937         ret = xhci_do_dbc_init(xhci);
938         if (ret)
939                 goto init_err3;
940
941         ret = xhci_dbc_tty_register_driver(xhci);
942         if (ret)
943                 goto init_err2;
944
945         ret = device_create_file(dev, &dev_attr_dbc);
946         if (ret)
947                 goto init_err1;
948
949         return 0;
950
951 init_err1:
952         xhci_dbc_tty_unregister_driver();
953 init_err2:
954         xhci_do_dbc_exit(xhci);
955 init_err3:
956         return ret;
957 }
958
959 void xhci_dbc_exit(struct xhci_hcd *xhci)
960 {
961         struct device           *dev = xhci_to_hcd(xhci)->self.controller;
962
963         if (!xhci->dbc)
964                 return;
965
966         device_remove_file(dev, &dev_attr_dbc);
967         xhci_dbc_tty_unregister_driver();
968         xhci_dbc_stop(xhci);
969         xhci_do_dbc_exit(xhci);
970 }
971
972 #ifdef CONFIG_PM
973 int xhci_dbc_suspend(struct xhci_hcd *xhci)
974 {
975         struct xhci_dbc         *dbc = xhci->dbc;
976
977         if (!dbc)
978                 return 0;
979
980         if (dbc->state == DS_CONFIGURED)
981                 dbc->resume_required = 1;
982
983         xhci_dbc_stop(xhci);
984
985         return 0;
986 }
987
988 int xhci_dbc_resume(struct xhci_hcd *xhci)
989 {
990         int                     ret = 0;
991         struct xhci_dbc         *dbc = xhci->dbc;
992
993         if (!dbc)
994                 return 0;
995
996         if (dbc->resume_required) {
997                 dbc->resume_required = 0;
998                 xhci_dbc_start(xhci);
999         }
1000
1001         return ret;
1002 }
1003 #endif /* CONFIG_PM */