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WIP FPC-III support
[linux/fpc-iii.git] / drivers / bus / mhi / core / main.c
blobd34d7e90e38d9c5f9bf58ead5f945b23e273d648
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
4 *
5 */
6
7 #include <linux/device.h>
8 #include <linux/dma-direction.h>
9 #include <linux/dma-mapping.h>
10 #include <linux/interrupt.h>
11 #include <linux/list.h>
12 #include <linux/mhi.h>
13 #include <linux/module.h>
14 #include <linux/skbuff.h>
15 #include <linux/slab.h>
16 #include "internal.h"
17
18 int __must_check mhi_read_reg(struct mhi_controller *mhi_cntrl,
19 void __iomem *base, u32 offset, u32 *out)
20 {
21 return mhi_cntrl->read_reg(mhi_cntrl, base + offset, out);
22 }
23
24 int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl,
25 void __iomem *base, u32 offset,
26 u32 mask, u32 shift, u32 *out)
27 {
28 u32 tmp;
29 int ret;
30
31 ret = mhi_read_reg(mhi_cntrl, base, offset, &tmp);
32 if (ret)
33 return ret;
34
35 *out = (tmp & mask) >> shift;
36
37 return 0;
38 }
39
40 void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base,
41 u32 offset, u32 val)
42 {
43 mhi_cntrl->write_reg(mhi_cntrl, base + offset, val);
44 }
45
46 void mhi_write_reg_field(struct mhi_controller *mhi_cntrl, void __iomem *base,
47 u32 offset, u32 mask, u32 shift, u32 val)
48 {
49 int ret;
50 u32 tmp;
51
52 ret = mhi_read_reg(mhi_cntrl, base, offset, &tmp);
53 if (ret)
54 return;
55
56 tmp &= ~mask;
57 tmp |= (val << shift);
58 mhi_write_reg(mhi_cntrl, base, offset, tmp);
59 }
60
61 void mhi_write_db(struct mhi_controller *mhi_cntrl, void __iomem *db_addr,
62 dma_addr_t db_val)
63 {
64 mhi_write_reg(mhi_cntrl, db_addr, 4, upper_32_bits(db_val));
65 mhi_write_reg(mhi_cntrl, db_addr, 0, lower_32_bits(db_val));
66 }
67
68 void mhi_db_brstmode(struct mhi_controller *mhi_cntrl,
69 struct db_cfg *db_cfg,
70 void __iomem *db_addr,
71 dma_addr_t db_val)
72 {
73 if (db_cfg->db_mode) {
74 db_cfg->db_val = db_val;
75 mhi_write_db(mhi_cntrl, db_addr, db_val);
76 db_cfg->db_mode = 0;
77 }
78 }
79
80 void mhi_db_brstmode_disable(struct mhi_controller *mhi_cntrl,
81 struct db_cfg *db_cfg,
82 void __iomem *db_addr,
83 dma_addr_t db_val)
84 {
85 db_cfg->db_val = db_val;
86 mhi_write_db(mhi_cntrl, db_addr, db_val);
87 }
88
89 void mhi_ring_er_db(struct mhi_event *mhi_event)
90 {
91 struct mhi_ring *ring = &mhi_event->ring;
92
93 mhi_event->db_cfg.process_db(mhi_event->mhi_cntrl, &mhi_event->db_cfg,
94 ring->db_addr, *ring->ctxt_wp);
95 }
96
97 void mhi_ring_cmd_db(struct mhi_controller *mhi_cntrl, struct mhi_cmd *mhi_cmd)
98 {
99 dma_addr_t db;
100 struct mhi_ring *ring = &mhi_cmd->ring;
101
102 db = ring->iommu_base + (ring->wp - ring->base);
103 *ring->ctxt_wp = db;
104 mhi_write_db(mhi_cntrl, ring->db_addr, db);
105 }
106
107 void mhi_ring_chan_db(struct mhi_controller *mhi_cntrl,
108 struct mhi_chan *mhi_chan)
109 {
110 struct mhi_ring *ring = &mhi_chan->tre_ring;
111 dma_addr_t db;
112
113 db = ring->iommu_base + (ring->wp - ring->base);
114 *ring->ctxt_wp = db;
115 mhi_chan->db_cfg.process_db(mhi_cntrl, &mhi_chan->db_cfg,
116 ring->db_addr, db);
117 }
118
119 enum mhi_ee_type mhi_get_exec_env(struct mhi_controller *mhi_cntrl)
120 {
121 u32 exec;
122 int ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_EXECENV, &exec);
123
124 return (ret) ? MHI_EE_MAX : exec;
125 }
126 EXPORT_SYMBOL_GPL(mhi_get_exec_env);
127
128 enum mhi_state mhi_get_mhi_state(struct mhi_controller *mhi_cntrl)
129 {
130 u32 state;
131 int ret = mhi_read_reg_field(mhi_cntrl, mhi_cntrl->regs, MHISTATUS,
132 MHISTATUS_MHISTATE_MASK,
133 MHISTATUS_MHISTATE_SHIFT, &state);
134 return ret ? MHI_STATE_MAX : state;
135 }
136 EXPORT_SYMBOL_GPL(mhi_get_mhi_state);
137
138 int mhi_map_single_no_bb(struct mhi_controller *mhi_cntrl,
139 struct mhi_buf_info *buf_info)
140 {
141 buf_info->p_addr = dma_map_single(mhi_cntrl->cntrl_dev,
142 buf_info->v_addr, buf_info->len,
143 buf_info->dir);
144 if (dma_mapping_error(mhi_cntrl->cntrl_dev, buf_info->p_addr))
145 return -ENOMEM;
146
147 return 0;
148 }
149
150 int mhi_map_single_use_bb(struct mhi_controller *mhi_cntrl,
151 struct mhi_buf_info *buf_info)
152 {
153 void *buf = mhi_alloc_coherent(mhi_cntrl, buf_info->len,
154 &buf_info->p_addr, GFP_ATOMIC);
155
156 if (!buf)
157 return -ENOMEM;
158
159 if (buf_info->dir == DMA_TO_DEVICE)
160 memcpy(buf, buf_info->v_addr, buf_info->len);
161
162 buf_info->bb_addr = buf;
163
164 return 0;
165 }
166
167 void mhi_unmap_single_no_bb(struct mhi_controller *mhi_cntrl,
168 struct mhi_buf_info *buf_info)
169 {
170 dma_unmap_single(mhi_cntrl->cntrl_dev, buf_info->p_addr, buf_info->len,
171 buf_info->dir);
172 }
173
174 void mhi_unmap_single_use_bb(struct mhi_controller *mhi_cntrl,
175 struct mhi_buf_info *buf_info)
176 {
177 if (buf_info->dir == DMA_FROM_DEVICE)
178 memcpy(buf_info->v_addr, buf_info->bb_addr, buf_info->len);
179
180 mhi_free_coherent(mhi_cntrl, buf_info->len, buf_info->bb_addr,
181 buf_info->p_addr);
182 }
183
184 static int get_nr_avail_ring_elements(struct mhi_controller *mhi_cntrl,
185 struct mhi_ring *ring)
186 {
187 int nr_el;
188
189 if (ring->wp < ring->rp) {
190 nr_el = ((ring->rp - ring->wp) / ring->el_size) - 1;
191 } else {
192 nr_el = (ring->rp - ring->base) / ring->el_size;
193 nr_el += ((ring->base + ring->len - ring->wp) /
194 ring->el_size) - 1;
195 }
196
197 return nr_el;
198 }
199
200 static void *mhi_to_virtual(struct mhi_ring *ring, dma_addr_t addr)
201 {
202 return (addr - ring->iommu_base) + ring->base;
203 }
204
205 static void mhi_add_ring_element(struct mhi_controller *mhi_cntrl,
206 struct mhi_ring *ring)
207 {
208 ring->wp += ring->el_size;
209 if (ring->wp >= (ring->base + ring->len))
210 ring->wp = ring->base;
211 /* smp update */
212 smp_wmb();
213 }
214
215 static void mhi_del_ring_element(struct mhi_controller *mhi_cntrl,
216 struct mhi_ring *ring)
217 {
218 ring->rp += ring->el_size;
219 if (ring->rp >= (ring->base + ring->len))
220 ring->rp = ring->base;
221 /* smp update */
222 smp_wmb();
223 }
224
225 int mhi_destroy_device(struct device *dev, void *data)
226 {
227 struct mhi_device *mhi_dev;
228 struct mhi_controller *mhi_cntrl;
229
230 if (dev->bus != &mhi_bus_type)
231 return 0;
232
233 mhi_dev = to_mhi_device(dev);
234 mhi_cntrl = mhi_dev->mhi_cntrl;
235
236 /* Only destroy virtual devices thats attached to bus */
237 if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
238 return 0;
239
240 /*
241 * For the suspend and resume case, this function will get called
242 * without mhi_unregister_controller(). Hence, we need to drop the
243 * references to mhi_dev created for ul and dl channels. We can
244 * be sure that there will be no instances of mhi_dev left after
245 * this.
246 */
247 if (mhi_dev->ul_chan)
248 put_device(&mhi_dev->ul_chan->mhi_dev->dev);
249
250 if (mhi_dev->dl_chan)
251 put_device(&mhi_dev->dl_chan->mhi_dev->dev);
252
253 dev_dbg(&mhi_cntrl->mhi_dev->dev, "destroy device for chan:%s\n",
254 mhi_dev->name);
255
256 /* Notify the client and remove the device from MHI bus */
257 device_del(dev);
258 put_device(dev);
259
260 return 0;
261 }
262
263 void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason)
264 {
265 struct mhi_driver *mhi_drv;
266
267 if (!mhi_dev->dev.driver)
268 return;
269
270 mhi_drv = to_mhi_driver(mhi_dev->dev.driver);
271
272 if (mhi_drv->status_cb)
273 mhi_drv->status_cb(mhi_dev, cb_reason);
274 }
275 EXPORT_SYMBOL_GPL(mhi_notify);
276
277 /* Bind MHI channels to MHI devices */
278 void mhi_create_devices(struct mhi_controller *mhi_cntrl)
279 {
280 struct mhi_chan *mhi_chan;
281 struct mhi_device *mhi_dev;
282 struct device *dev = &mhi_cntrl->mhi_dev->dev;
283 int i, ret;
284
285 mhi_chan = mhi_cntrl->mhi_chan;
286 for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
287 if (!mhi_chan->configured || mhi_chan->mhi_dev ||
288 !(mhi_chan->ee_mask & BIT(mhi_cntrl->ee)))
289 continue;
290 mhi_dev = mhi_alloc_device(mhi_cntrl);
291 if (IS_ERR(mhi_dev))
292 return;
293
294 mhi_dev->dev_type = MHI_DEVICE_XFER;
295 switch (mhi_chan->dir) {
296 case DMA_TO_DEVICE:
297 mhi_dev->ul_chan = mhi_chan;
298 mhi_dev->ul_chan_id = mhi_chan->chan;
299 break;
300 case DMA_FROM_DEVICE:
301 /* We use dl_chan as offload channels */
302 mhi_dev->dl_chan = mhi_chan;
303 mhi_dev->dl_chan_id = mhi_chan->chan;
304 break;
305 default:
306 dev_err(dev, "Direction not supported\n");
307 put_device(&mhi_dev->dev);
308 return;
309 }
310
311 get_device(&mhi_dev->dev);
312 mhi_chan->mhi_dev = mhi_dev;
313
314 /* Check next channel if it matches */
315 if ((i + 1) < mhi_cntrl->max_chan && mhi_chan[1].configured) {
316 if (!strcmp(mhi_chan[1].name, mhi_chan->name)) {
317 i++;
318 mhi_chan++;
319 if (mhi_chan->dir == DMA_TO_DEVICE) {
320 mhi_dev->ul_chan = mhi_chan;
321 mhi_dev->ul_chan_id = mhi_chan->chan;
322 } else {
323 mhi_dev->dl_chan = mhi_chan;
324 mhi_dev->dl_chan_id = mhi_chan->chan;
325 }
326 get_device(&mhi_dev->dev);
327 mhi_chan->mhi_dev = mhi_dev;
328 }
329 }
330
331 /* Channel name is same for both UL and DL */
332 mhi_dev->name = mhi_chan->name;
333 dev_set_name(&mhi_dev->dev, "%s_%s",
334 dev_name(&mhi_cntrl->mhi_dev->dev),
335 mhi_dev->name);
336
337 /* Init wakeup source if available */
338 if (mhi_dev->dl_chan && mhi_dev->dl_chan->wake_capable)
339 device_init_wakeup(&mhi_dev->dev, true);
340
341 ret = device_add(&mhi_dev->dev);
342 if (ret)
343 put_device(&mhi_dev->dev);
344 }
345 }
346
347 irqreturn_t mhi_irq_handler(int irq_number, void *dev)
348 {
349 struct mhi_event *mhi_event = dev;
350 struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl;
351 struct mhi_event_ctxt *er_ctxt =
352 &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index];
353 struct mhi_ring *ev_ring = &mhi_event->ring;
354 void *dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
355
356 /* Only proceed if event ring has pending events */
357 if (ev_ring->rp == dev_rp)
358 return IRQ_HANDLED;
359
360 /* For client managed event ring, notify pending data */
361 if (mhi_event->cl_manage) {
362 struct mhi_chan *mhi_chan = mhi_event->mhi_chan;
363 struct mhi_device *mhi_dev = mhi_chan->mhi_dev;
364
365 if (mhi_dev)
366 mhi_notify(mhi_dev, MHI_CB_PENDING_DATA);
367 } else {
368 tasklet_schedule(&mhi_event->task);
369 }
370
371 return IRQ_HANDLED;
372 }
373
374 irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)
375 {
376 struct mhi_controller *mhi_cntrl = priv;
377 struct device *dev = &mhi_cntrl->mhi_dev->dev;
378 enum mhi_state state = MHI_STATE_MAX;
379 enum mhi_pm_state pm_state = 0;
380 enum mhi_ee_type ee = 0;
381
382 write_lock_irq(&mhi_cntrl->pm_lock);
383 if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
384 write_unlock_irq(&mhi_cntrl->pm_lock);
385 goto exit_intvec;
386 }
387
388 state = mhi_get_mhi_state(mhi_cntrl);
389 ee = mhi_cntrl->ee;
390 mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl);
391 dev_dbg(dev, "local ee:%s device ee:%s dev_state:%s\n",
392 TO_MHI_EXEC_STR(mhi_cntrl->ee), TO_MHI_EXEC_STR(ee),
393 TO_MHI_STATE_STR(state));
394
395 if (state == MHI_STATE_SYS_ERR) {
396 dev_dbg(dev, "System error detected\n");
397 pm_state = mhi_tryset_pm_state(mhi_cntrl,
398 MHI_PM_SYS_ERR_DETECT);
399 }
400 write_unlock_irq(&mhi_cntrl->pm_lock);
401
402 /* If device supports RDDM don't bother processing SYS error */
403 if (mhi_cntrl->rddm_image) {
404 /* host may be performing a device power down already */
405 if (!mhi_is_active(mhi_cntrl))
406 goto exit_intvec;
407
408 if (mhi_cntrl->ee == MHI_EE_RDDM && mhi_cntrl->ee != ee) {
409 mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_RDDM);
410 wake_up_all(&mhi_cntrl->state_event);
411 }
412 goto exit_intvec;
413 }
414
415 if (pm_state == MHI_PM_SYS_ERR_DETECT) {
416 wake_up_all(&mhi_cntrl->state_event);
417
418 /* For fatal errors, we let controller decide next step */
419 if (MHI_IN_PBL(ee))
420 mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_FATAL_ERROR);
421 else
422 mhi_pm_sys_err_handler(mhi_cntrl);
423 }
424
425 exit_intvec:
426
427 return IRQ_HANDLED;
428 }
429
430 irqreturn_t mhi_intvec_handler(int irq_number, void *dev)
431 {
432 struct mhi_controller *mhi_cntrl = dev;
433
434 /* Wake up events waiting for state change */
435 wake_up_all(&mhi_cntrl->state_event);
436
437 return IRQ_WAKE_THREAD;
438 }
439
440 static void mhi_recycle_ev_ring_element(struct mhi_controller *mhi_cntrl,
441 struct mhi_ring *ring)
442 {
443 dma_addr_t ctxt_wp;
444
445 /* Update the WP */
446 ring->wp += ring->el_size;
447 ctxt_wp = *ring->ctxt_wp + ring->el_size;
448
449 if (ring->wp >= (ring->base + ring->len)) {
450 ring->wp = ring->base;
451 ctxt_wp = ring->iommu_base;
452 }
453
454 *ring->ctxt_wp = ctxt_wp;
455
456 /* Update the RP */
457 ring->rp += ring->el_size;
458 if (ring->rp >= (ring->base + ring->len))
459 ring->rp = ring->base;
460
461 /* Update to all cores */
462 smp_wmb();
463 }
464
465 static int parse_xfer_event(struct mhi_controller *mhi_cntrl,
466 struct mhi_tre *event,
467 struct mhi_chan *mhi_chan)
468 {
469 struct mhi_ring *buf_ring, *tre_ring;
470 struct device *dev = &mhi_cntrl->mhi_dev->dev;
471 struct mhi_result result;
472 unsigned long flags = 0;
473 u32 ev_code;
474
475 ev_code = MHI_TRE_GET_EV_CODE(event);
476 buf_ring = &mhi_chan->buf_ring;
477 tre_ring = &mhi_chan->tre_ring;
478
479 result.transaction_status = (ev_code == MHI_EV_CC_OVERFLOW) ?
480 -EOVERFLOW : 0;
481
482 /*
483 * If it's a DB Event then we need to grab the lock
484 * with preemption disabled and as a write because we
485 * have to update db register and there are chances that
486 * another thread could be doing the same.
487 */
488 if (ev_code >= MHI_EV_CC_OOB)
489 write_lock_irqsave(&mhi_chan->lock, flags);
490 else
491 read_lock_bh(&mhi_chan->lock);
492
493 if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED)
494 goto end_process_tx_event;
495
496 switch (ev_code) {
497 case MHI_EV_CC_OVERFLOW:
498 case MHI_EV_CC_EOB:
499 case MHI_EV_CC_EOT:
500 {
501 dma_addr_t ptr = MHI_TRE_GET_EV_PTR(event);
502 struct mhi_tre *local_rp, *ev_tre;
503 void *dev_rp;
504 struct mhi_buf_info *buf_info;
505 u16 xfer_len;
506
507 /* Get the TRB this event points to */
508 ev_tre = mhi_to_virtual(tre_ring, ptr);
509
510 dev_rp = ev_tre + 1;
511 if (dev_rp >= (tre_ring->base + tre_ring->len))
512 dev_rp = tre_ring->base;
513
514 result.dir = mhi_chan->dir;
515
516 local_rp = tre_ring->rp;
517 while (local_rp != dev_rp) {
518 buf_info = buf_ring->rp;
519 /* If it's the last TRE, get length from the event */
520 if (local_rp == ev_tre)
521 xfer_len = MHI_TRE_GET_EV_LEN(event);
522 else
523 xfer_len = buf_info->len;
524
525 /* Unmap if it's not pre-mapped by client */
526 if (likely(!buf_info->pre_mapped))
527 mhi_cntrl->unmap_single(mhi_cntrl, buf_info);
528
529 result.buf_addr = buf_info->cb_buf;
530
531 /* truncate to buf len if xfer_len is larger */
532 result.bytes_xferd =
533 min_t(u16, xfer_len, buf_info->len);
534 mhi_del_ring_element(mhi_cntrl, buf_ring);
535 mhi_del_ring_element(mhi_cntrl, tre_ring);
536 local_rp = tre_ring->rp;
537
538 /* notify client */
539 mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
540
541 if (mhi_chan->dir == DMA_TO_DEVICE)
542 atomic_dec(&mhi_cntrl->pending_pkts);
543
544 /*
545 * Recycle the buffer if buffer is pre-allocated,
546 * if there is an error, not much we can do apart
547 * from dropping the packet
548 */
549 if (mhi_chan->pre_alloc) {
550 if (mhi_queue_buf(mhi_chan->mhi_dev,
551 mhi_chan->dir,
552 buf_info->cb_buf,
553 buf_info->len, MHI_EOT)) {
554 dev_err(dev,
555 "Error recycling buffer for chan:%d\n",
556 mhi_chan->chan);
557 kfree(buf_info->cb_buf);
558 }
559 }
560 }
561 break;
562 } /* CC_EOT */
563 case MHI_EV_CC_OOB:
564 case MHI_EV_CC_DB_MODE:
565 {
566 unsigned long flags;
567
568 mhi_chan->db_cfg.db_mode = 1;
569 read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
570 if (tre_ring->wp != tre_ring->rp &&
571 MHI_DB_ACCESS_VALID(mhi_cntrl)) {
572 mhi_ring_chan_db(mhi_cntrl, mhi_chan);
573 }
574 read_unlock_irqrestore(&mhi_cntrl->pm_lock, flags);
575 break;
576 }
577 case MHI_EV_CC_BAD_TRE:
578 default:
579 dev_err(dev, "Unknown event 0x%x\n", ev_code);
580 break;
581 } /* switch(MHI_EV_READ_CODE(EV_TRB_CODE,event)) */
582
583 end_process_tx_event:
584 if (ev_code >= MHI_EV_CC_OOB)
585 write_unlock_irqrestore(&mhi_chan->lock, flags);
586 else
587 read_unlock_bh(&mhi_chan->lock);
588
589 return 0;
590 }
591
592 static int parse_rsc_event(struct mhi_controller *mhi_cntrl,
593 struct mhi_tre *event,
594 struct mhi_chan *mhi_chan)
595 {
596 struct mhi_ring *buf_ring, *tre_ring;
597 struct mhi_buf_info *buf_info;
598 struct mhi_result result;
599 int ev_code;
600 u32 cookie; /* offset to local descriptor */
601 u16 xfer_len;
602
603 buf_ring = &mhi_chan->buf_ring;
604 tre_ring = &mhi_chan->tre_ring;
605
606 ev_code = MHI_TRE_GET_EV_CODE(event);
607 cookie = MHI_TRE_GET_EV_COOKIE(event);
608 xfer_len = MHI_TRE_GET_EV_LEN(event);
609
610 /* Received out of bound cookie */
611 WARN_ON(cookie >= buf_ring->len);
612
613 buf_info = buf_ring->base + cookie;
614
615 result.transaction_status = (ev_code == MHI_EV_CC_OVERFLOW) ?
616 -EOVERFLOW : 0;
617
618 /* truncate to buf len if xfer_len is larger */
619 result.bytes_xferd = min_t(u16, xfer_len, buf_info->len);
620 result.buf_addr = buf_info->cb_buf;
621 result.dir = mhi_chan->dir;
622
623 read_lock_bh(&mhi_chan->lock);
624
625 if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED)
626 goto end_process_rsc_event;
627
628 WARN_ON(!buf_info->used);
629
630 /* notify the client */
631 mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
632
633 /*
634 * Note: We're arbitrarily incrementing RP even though, completion
635 * packet we processed might not be the same one, reason we can do this
636 * is because device guaranteed to cache descriptors in order it
637 * receive, so even though completion event is different we can re-use
638 * all descriptors in between.
639 * Example:
640 * Transfer Ring has descriptors: A, B, C, D
641 * Last descriptor host queue is D (WP) and first descriptor
642 * host queue is A (RP).
643 * The completion event we just serviced is descriptor C.
644 * Then we can safely queue descriptors to replace A, B, and C
645 * even though host did not receive any completions.
646 */
647 mhi_del_ring_element(mhi_cntrl, tre_ring);
648 buf_info->used = false;
649
650 end_process_rsc_event:
651 read_unlock_bh(&mhi_chan->lock);
652
653 return 0;
654 }
655
656 static void mhi_process_cmd_completion(struct mhi_controller *mhi_cntrl,
657 struct mhi_tre *tre)
658 {
659 dma_addr_t ptr = MHI_TRE_GET_EV_PTR(tre);
660 struct mhi_cmd *cmd_ring = &mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING];
661 struct mhi_ring *mhi_ring = &cmd_ring->ring;
662 struct mhi_tre *cmd_pkt;
663 struct mhi_chan *mhi_chan;
664 u32 chan;
665
666 cmd_pkt = mhi_to_virtual(mhi_ring, ptr);
667
668 chan = MHI_TRE_GET_CMD_CHID(cmd_pkt);
669 mhi_chan = &mhi_cntrl->mhi_chan[chan];
670 write_lock_bh(&mhi_chan->lock);
671 mhi_chan->ccs = MHI_TRE_GET_EV_CODE(tre);
672 complete(&mhi_chan->completion);
673 write_unlock_bh(&mhi_chan->lock);
674
675 mhi_del_ring_element(mhi_cntrl, mhi_ring);
676 }
677
678 int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl,
679 struct mhi_event *mhi_event,
680 u32 event_quota)
681 {
682 struct mhi_tre *dev_rp, *local_rp;
683 struct mhi_ring *ev_ring = &mhi_event->ring;
684 struct mhi_event_ctxt *er_ctxt =
685 &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index];
686 struct mhi_chan *mhi_chan;
687 struct device *dev = &mhi_cntrl->mhi_dev->dev;
688 u32 chan;
689 int count = 0;
690
691 /*
692 * This is a quick check to avoid unnecessary event processing
693 * in case MHI is already in error state, but it's still possible
694 * to transition to error state while processing events
695 */
696 if (unlikely(MHI_EVENT_ACCESS_INVALID(mhi_cntrl->pm_state)))
697 return -EIO;
698
699 dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
700 local_rp = ev_ring->rp;
701
702 while (dev_rp != local_rp) {
703 enum mhi_pkt_type type = MHI_TRE_GET_EV_TYPE(local_rp);
704
705 switch (type) {
706 case MHI_PKT_TYPE_BW_REQ_EVENT:
707 {
708 struct mhi_link_info *link_info;
709
710 link_info = &mhi_cntrl->mhi_link_info;
711 write_lock_irq(&mhi_cntrl->pm_lock);
712 link_info->target_link_speed =
713 MHI_TRE_GET_EV_LINKSPEED(local_rp);
714 link_info->target_link_width =
715 MHI_TRE_GET_EV_LINKWIDTH(local_rp);
716 write_unlock_irq(&mhi_cntrl->pm_lock);
717 dev_dbg(dev, "Received BW_REQ event\n");
718 mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_BW_REQ);
719 break;
720 }
721 case MHI_PKT_TYPE_STATE_CHANGE_EVENT:
722 {
723 enum mhi_state new_state;
724
725 new_state = MHI_TRE_GET_EV_STATE(local_rp);
726
727 dev_dbg(dev, "State change event to state: %s\n",
728 TO_MHI_STATE_STR(new_state));
729
730 switch (new_state) {
731 case MHI_STATE_M0:
732 mhi_pm_m0_transition(mhi_cntrl);
733 break;
734 case MHI_STATE_M1:
735 mhi_pm_m1_transition(mhi_cntrl);
736 break;
737 case MHI_STATE_M3:
738 mhi_pm_m3_transition(mhi_cntrl);
739 break;
740 case MHI_STATE_SYS_ERR:
741 {
742 enum mhi_pm_state new_state;
743
744 dev_dbg(dev, "System error detected\n");
745 write_lock_irq(&mhi_cntrl->pm_lock);
746 new_state = mhi_tryset_pm_state(mhi_cntrl,
747 MHI_PM_SYS_ERR_DETECT);
748 write_unlock_irq(&mhi_cntrl->pm_lock);
749 if (new_state == MHI_PM_SYS_ERR_DETECT)
750 mhi_pm_sys_err_handler(mhi_cntrl);
751 break;
752 }
753 default:
754 dev_err(dev, "Invalid state: %s\n",
755 TO_MHI_STATE_STR(new_state));
756 }
757
758 break;
759 }
760 case MHI_PKT_TYPE_CMD_COMPLETION_EVENT:
761 mhi_process_cmd_completion(mhi_cntrl, local_rp);
762 break;
763 case MHI_PKT_TYPE_EE_EVENT:
764 {
765 enum dev_st_transition st = DEV_ST_TRANSITION_MAX;
766 enum mhi_ee_type event = MHI_TRE_GET_EV_EXECENV(local_rp);
767
768 dev_dbg(dev, "Received EE event: %s\n",
769 TO_MHI_EXEC_STR(event));
770 switch (event) {
771 case MHI_EE_SBL:
772 st = DEV_ST_TRANSITION_SBL;
773 break;
774 case MHI_EE_WFW:
775 case MHI_EE_AMSS:
776 st = DEV_ST_TRANSITION_MISSION_MODE;
777 break;
778 case MHI_EE_RDDM:
779 mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_RDDM);
780 write_lock_irq(&mhi_cntrl->pm_lock);
781 mhi_cntrl->ee = event;
782 write_unlock_irq(&mhi_cntrl->pm_lock);
783 wake_up_all(&mhi_cntrl->state_event);
784 break;
785 default:
786 dev_err(dev,
787 "Unhandled EE event: 0x%x\n", type);
788 }
789 if (st != DEV_ST_TRANSITION_MAX)
790 mhi_queue_state_transition(mhi_cntrl, st);
791
792 break;
793 }
794 case MHI_PKT_TYPE_TX_EVENT:
795 chan = MHI_TRE_GET_EV_CHID(local_rp);
796
797 WARN_ON(chan >= mhi_cntrl->max_chan);
798
799 /*
800 * Only process the event ring elements whose channel
801 * ID is within the maximum supported range.
802 */
803 if (chan < mhi_cntrl->max_chan) {
804 mhi_chan = &mhi_cntrl->mhi_chan[chan];
805 parse_xfer_event(mhi_cntrl, local_rp, mhi_chan);
806 event_quota--;
807 }
808 break;
809 default:
810 dev_err(dev, "Unhandled event type: %d\n", type);
811 break;
812 }
813
814 mhi_recycle_ev_ring_element(mhi_cntrl, ev_ring);
815 local_rp = ev_ring->rp;
816 dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
817 count++;
818 }
819
820 read_lock_bh(&mhi_cntrl->pm_lock);
821 if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)))
822 mhi_ring_er_db(mhi_event);
823 read_unlock_bh(&mhi_cntrl->pm_lock);
824
825 return count;
826 }
827
828 int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl,
829 struct mhi_event *mhi_event,
830 u32 event_quota)
831 {
832 struct mhi_tre *dev_rp, *local_rp;
833 struct mhi_ring *ev_ring = &mhi_event->ring;
834 struct mhi_event_ctxt *er_ctxt =
835 &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index];
836 int count = 0;
837 u32 chan;
838 struct mhi_chan *mhi_chan;
839
840 if (unlikely(MHI_EVENT_ACCESS_INVALID(mhi_cntrl->pm_state)))
841 return -EIO;
842
843 dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
844 local_rp = ev_ring->rp;
845
846 while (dev_rp != local_rp && event_quota > 0) {
847 enum mhi_pkt_type type = MHI_TRE_GET_EV_TYPE(local_rp);
848
849 chan = MHI_TRE_GET_EV_CHID(local_rp);
850
851 WARN_ON(chan >= mhi_cntrl->max_chan);
852
853 /*
854 * Only process the event ring elements whose channel
855 * ID is within the maximum supported range.
856 */
857 if (chan < mhi_cntrl->max_chan) {
858 mhi_chan = &mhi_cntrl->mhi_chan[chan];
859
860 if (likely(type == MHI_PKT_TYPE_TX_EVENT)) {
861 parse_xfer_event(mhi_cntrl, local_rp, mhi_chan);
862 event_quota--;
863 } else if (type == MHI_PKT_TYPE_RSC_TX_EVENT) {
864 parse_rsc_event(mhi_cntrl, local_rp, mhi_chan);
865 event_quota--;
866 }
867 }
868
869 mhi_recycle_ev_ring_element(mhi_cntrl, ev_ring);
870 local_rp = ev_ring->rp;
871 dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
872 count++;
873 }
874 read_lock_bh(&mhi_cntrl->pm_lock);
875 if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)))
876 mhi_ring_er_db(mhi_event);
877 read_unlock_bh(&mhi_cntrl->pm_lock);
878
879 return count;
880 }
881
882 void mhi_ev_task(unsigned long data)
883 {
884 struct mhi_event *mhi_event = (struct mhi_event *)data;
885 struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl;
886
887 /* process all pending events */
888 spin_lock_bh(&mhi_event->lock);
889 mhi_event->process_event(mhi_cntrl, mhi_event, U32_MAX);
890 spin_unlock_bh(&mhi_event->lock);
891 }
892
893 void mhi_ctrl_ev_task(unsigned long data)
894 {
895 struct mhi_event *mhi_event = (struct mhi_event *)data;
896 struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl;
897 struct device *dev = &mhi_cntrl->mhi_dev->dev;
898 enum mhi_state state;
899 enum mhi_pm_state pm_state = 0;
900 int ret;
901
902 /*
903 * We can check PM state w/o a lock here because there is no way
904 * PM state can change from reg access valid to no access while this
905 * thread being executed.
906 */
907 if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
908 /*
909 * We may have a pending event but not allowed to
910 * process it since we are probably in a suspended state,
911 * so trigger a resume.
912 */
913 mhi_trigger_resume(mhi_cntrl);
914
915 return;
916 }
917
918 /* Process ctrl events events */
919 ret = mhi_event->process_event(mhi_cntrl, mhi_event, U32_MAX);
920
921 /*
922 * We received an IRQ but no events to process, maybe device went to
923 * SYS_ERR state? Check the state to confirm.
924 */
925 if (!ret) {
926 write_lock_irq(&mhi_cntrl->pm_lock);
927 state = mhi_get_mhi_state(mhi_cntrl);
928 if (state == MHI_STATE_SYS_ERR) {
929 dev_dbg(dev, "System error detected\n");
930 pm_state = mhi_tryset_pm_state(mhi_cntrl,
931 MHI_PM_SYS_ERR_DETECT);
932 }
933 write_unlock_irq(&mhi_cntrl->pm_lock);
934 if (pm_state == MHI_PM_SYS_ERR_DETECT)
935 mhi_pm_sys_err_handler(mhi_cntrl);
936 }
937 }
938
939 static bool mhi_is_ring_full(struct mhi_controller *mhi_cntrl,
940 struct mhi_ring *ring)
941 {
942 void *tmp = ring->wp + ring->el_size;
943
944 if (tmp >= (ring->base + ring->len))
945 tmp = ring->base;
946
947 return (tmp == ring->rp);
948 }
949
950 int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
951 struct sk_buff *skb, size_t len, enum mhi_flags mflags)
952 {
953 struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
954 struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? mhi_dev->ul_chan :
955 mhi_dev->dl_chan;
956 struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
957 struct mhi_buf_info buf_info = { };
958 int ret;
959
960 /* If MHI host pre-allocates buffers then client drivers cannot queue */
961 if (mhi_chan->pre_alloc)
962 return -EINVAL;
963
964 if (mhi_is_ring_full(mhi_cntrl, tre_ring))
965 return -ENOMEM;
966
967 read_lock_bh(&mhi_cntrl->pm_lock);
968 if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))) {
969 read_unlock_bh(&mhi_cntrl->pm_lock);
970 return -EIO;
971 }
972
973 /* we're in M3 or transitioning to M3 */
974 if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
975 mhi_trigger_resume(mhi_cntrl);
976
977 /* Toggle wake to exit out of M2 */
978 mhi_cntrl->wake_toggle(mhi_cntrl);
979
980 buf_info.v_addr = skb->data;
981 buf_info.cb_buf = skb;
982 buf_info.len = len;
983
984 ret = mhi_gen_tre(mhi_cntrl, mhi_chan, &buf_info, mflags);
985 if (unlikely(ret)) {
986 read_unlock_bh(&mhi_cntrl->pm_lock);
987 return ret;
988 }
989
990 if (mhi_chan->dir == DMA_TO_DEVICE)
991 atomic_inc(&mhi_cntrl->pending_pkts);
992
993 if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) {
994 read_lock_bh(&mhi_chan->lock);
995 mhi_ring_chan_db(mhi_cntrl, mhi_chan);
996 read_unlock_bh(&mhi_chan->lock);
997 }
998
999 read_unlock_bh(&mhi_cntrl->pm_lock);
1000
1001 return 0;
1002 }
1003 EXPORT_SYMBOL_GPL(mhi_queue_skb);
1004
1005 int mhi_queue_dma(struct mhi_device *mhi_dev, enum dma_data_direction dir,
1006 struct mhi_buf *mhi_buf, size_t len, enum mhi_flags mflags)
1007 {
1008 struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1009 struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? mhi_dev->ul_chan :
1010 mhi_dev->dl_chan;
1011 struct device *dev = &mhi_cntrl->mhi_dev->dev;
1012 struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
1013 struct mhi_buf_info buf_info = { };
1014 int ret;
1015
1016 /* If MHI host pre-allocates buffers then client drivers cannot queue */
1017 if (mhi_chan->pre_alloc)
1018 return -EINVAL;
1019
1020 if (mhi_is_ring_full(mhi_cntrl, tre_ring))
1021 return -ENOMEM;
1022
1023 read_lock_bh(&mhi_cntrl->pm_lock);
1024 if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))) {
1025 dev_err(dev, "MHI is not in activate state, PM state: %s\n",
1026 to_mhi_pm_state_str(mhi_cntrl->pm_state));
1027 read_unlock_bh(&mhi_cntrl->pm_lock);
1028
1029 return -EIO;
1030 }
1031
1032 /* we're in M3 or transitioning to M3 */
1033 if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
1034 mhi_trigger_resume(mhi_cntrl);
1035
1036 /* Toggle wake to exit out of M2 */
1037 mhi_cntrl->wake_toggle(mhi_cntrl);
1038
1039 buf_info.p_addr = mhi_buf->dma_addr;
1040 buf_info.cb_buf = mhi_buf;
1041 buf_info.pre_mapped = true;
1042 buf_info.len = len;
1043
1044 ret = mhi_gen_tre(mhi_cntrl, mhi_chan, &buf_info, mflags);
1045 if (unlikely(ret)) {
1046 read_unlock_bh(&mhi_cntrl->pm_lock);
1047 return ret;
1048 }
1049
1050 if (mhi_chan->dir == DMA_TO_DEVICE)
1051 atomic_inc(&mhi_cntrl->pending_pkts);
1052
1053 if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) {
1054 read_lock_bh(&mhi_chan->lock);
1055 mhi_ring_chan_db(mhi_cntrl, mhi_chan);
1056 read_unlock_bh(&mhi_chan->lock);
1057 }
1058
1059 read_unlock_bh(&mhi_cntrl->pm_lock);
1060
1061 return 0;
1062 }
1063 EXPORT_SYMBOL_GPL(mhi_queue_dma);
1064
1065 int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
1066 struct mhi_buf_info *info, enum mhi_flags flags)
1067 {
1068 struct mhi_ring *buf_ring, *tre_ring;
1069 struct mhi_tre *mhi_tre;
1070 struct mhi_buf_info *buf_info;
1071 int eot, eob, chain, bei;
1072 int ret;
1073
1074 buf_ring = &mhi_chan->buf_ring;
1075 tre_ring = &mhi_chan->tre_ring;
1076
1077 buf_info = buf_ring->wp;
1078 WARN_ON(buf_info->used);
1079 buf_info->pre_mapped = info->pre_mapped;
1080 if (info->pre_mapped)
1081 buf_info->p_addr = info->p_addr;
1082 else
1083 buf_info->v_addr = info->v_addr;
1084 buf_info->cb_buf = info->cb_buf;
1085 buf_info->wp = tre_ring->wp;
1086 buf_info->dir = mhi_chan->dir;
1087 buf_info->len = info->len;
1088
1089 if (!info->pre_mapped) {
1090 ret = mhi_cntrl->map_single(mhi_cntrl, buf_info);
1091 if (ret)
1092 return ret;
1093 }
1094
1095 eob = !!(flags & MHI_EOB);
1096 eot = !!(flags & MHI_EOT);
1097 chain = !!(flags & MHI_CHAIN);
1098 bei = !!(mhi_chan->intmod);
1099
1100 mhi_tre = tre_ring->wp;
1101 mhi_tre->ptr = MHI_TRE_DATA_PTR(buf_info->p_addr);
1102 mhi_tre->dword[0] = MHI_TRE_DATA_DWORD0(info->len);
1103 mhi_tre->dword[1] = MHI_TRE_DATA_DWORD1(bei, eot, eob, chain);
1104
1105 /* increment WP */
1106 mhi_add_ring_element(mhi_cntrl, tre_ring);
1107 mhi_add_ring_element(mhi_cntrl, buf_ring);
1108
1109 return 0;
1110 }
1111
1112 int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir,
1113 void *buf, size_t len, enum mhi_flags mflags)
1114 {
1115 struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1116 struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? mhi_dev->ul_chan :
1117 mhi_dev->dl_chan;
1118 struct mhi_ring *tre_ring;
1119 struct mhi_buf_info buf_info = { };
1120 unsigned long flags;
1121 int ret;
1122
1123 /*
1124 * this check here only as a guard, it's always
1125 * possible mhi can enter error while executing rest of function,
1126 * which is not fatal so we do not need to hold pm_lock
1127 */
1128 if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)))
1129 return -EIO;
1130
1131 tre_ring = &mhi_chan->tre_ring;
1132 if (mhi_is_ring_full(mhi_cntrl, tre_ring))
1133 return -ENOMEM;
1134
1135 buf_info.v_addr = buf;
1136 buf_info.cb_buf = buf;
1137 buf_info.len = len;
1138
1139 ret = mhi_gen_tre(mhi_cntrl, mhi_chan, &buf_info, mflags);
1140 if (unlikely(ret))
1141 return ret;
1142
1143 read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
1144
1145 /* we're in M3 or transitioning to M3 */
1146 if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
1147 mhi_trigger_resume(mhi_cntrl);
1148
1149 /* Toggle wake to exit out of M2 */
1150 mhi_cntrl->wake_toggle(mhi_cntrl);
1151
1152 if (mhi_chan->dir == DMA_TO_DEVICE)
1153 atomic_inc(&mhi_cntrl->pending_pkts);
1154
1155 if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) {
1156 unsigned long flags;
1157
1158 read_lock_irqsave(&mhi_chan->lock, flags);
1159 mhi_ring_chan_db(mhi_cntrl, mhi_chan);
1160 read_unlock_irqrestore(&mhi_chan->lock, flags);
1161 }
1162
1163 read_unlock_irqrestore(&mhi_cntrl->pm_lock, flags);
1164
1165 return 0;
1166 }
1167 EXPORT_SYMBOL_GPL(mhi_queue_buf);
1168
1169 bool mhi_queue_is_full(struct mhi_device *mhi_dev, enum dma_data_direction dir)
1170 {
1171 struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1172 struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ?
1173 mhi_dev->ul_chan : mhi_dev->dl_chan;
1174 struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
1175
1176 return mhi_is_ring_full(mhi_cntrl, tre_ring);
1177 }
1178 EXPORT_SYMBOL_GPL(mhi_queue_is_full);
1179
1180 int mhi_send_cmd(struct mhi_controller *mhi_cntrl,
1181 struct mhi_chan *mhi_chan,
1182 enum mhi_cmd_type cmd)
1183 {
1184 struct mhi_tre *cmd_tre = NULL;
1185 struct mhi_cmd *mhi_cmd = &mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING];
1186 struct mhi_ring *ring = &mhi_cmd->ring;
1187 struct device *dev = &mhi_cntrl->mhi_dev->dev;
1188 int chan = 0;
1189
1190 if (mhi_chan)
1191 chan = mhi_chan->chan;
1192
1193 spin_lock_bh(&mhi_cmd->lock);
1194 if (!get_nr_avail_ring_elements(mhi_cntrl, ring)) {
1195 spin_unlock_bh(&mhi_cmd->lock);
1196 return -ENOMEM;
1197 }
1198
1199 /* prepare the cmd tre */
1200 cmd_tre = ring->wp;
1201 switch (cmd) {
1202 case MHI_CMD_RESET_CHAN:
1203 cmd_tre->ptr = MHI_TRE_CMD_RESET_PTR;
1204 cmd_tre->dword[0] = MHI_TRE_CMD_RESET_DWORD0;
1205 cmd_tre->dword[1] = MHI_TRE_CMD_RESET_DWORD1(chan);
1206 break;
1207 case MHI_CMD_START_CHAN:
1208 cmd_tre->ptr = MHI_TRE_CMD_START_PTR;
1209 cmd_tre->dword[0] = MHI_TRE_CMD_START_DWORD0;
1210 cmd_tre->dword[1] = MHI_TRE_CMD_START_DWORD1(chan);
1211 break;
1212 default:
1213 dev_err(dev, "Command not supported\n");
1214 break;
1215 }
1216
1217 /* queue to hardware */
1218 mhi_add_ring_element(mhi_cntrl, ring);
1219 read_lock_bh(&mhi_cntrl->pm_lock);
1220 if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)))
1221 mhi_ring_cmd_db(mhi_cntrl, mhi_cmd);
1222 read_unlock_bh(&mhi_cntrl->pm_lock);
1223 spin_unlock_bh(&mhi_cmd->lock);
1224
1225 return 0;
1226 }
1227
1228 static void __mhi_unprepare_channel(struct mhi_controller *mhi_cntrl,
1229 struct mhi_chan *mhi_chan)
1230 {
1231 int ret;
1232 struct device *dev = &mhi_cntrl->mhi_dev->dev;
1233
1234 dev_dbg(dev, "Entered: unprepare channel:%d\n", mhi_chan->chan);
1235
1236 /* no more processing events for this channel */
1237 mutex_lock(&mhi_chan->mutex);
1238 write_lock_irq(&mhi_chan->lock);
1239 if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED &&
1240 mhi_chan->ch_state != MHI_CH_STATE_SUSPENDED) {
1241 write_unlock_irq(&mhi_chan->lock);
1242 mutex_unlock(&mhi_chan->mutex);
1243 return;
1244 }
1245
1246 mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
1247 write_unlock_irq(&mhi_chan->lock);
1248
1249 reinit_completion(&mhi_chan->completion);
1250 read_lock_bh(&mhi_cntrl->pm_lock);
1251 if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
1252 read_unlock_bh(&mhi_cntrl->pm_lock);
1253 goto error_invalid_state;
1254 }
1255
1256 mhi_cntrl->wake_toggle(mhi_cntrl);
1257 read_unlock_bh(&mhi_cntrl->pm_lock);
1258
1259 mhi_cntrl->runtime_get(mhi_cntrl);
1260 mhi_cntrl->runtime_put(mhi_cntrl);
1261 ret = mhi_send_cmd(mhi_cntrl, mhi_chan, MHI_CMD_RESET_CHAN);
1262 if (ret)
1263 goto error_invalid_state;
1264
1265 /* even if it fails we will still reset */
1266 ret = wait_for_completion_timeout(&mhi_chan->completion,
1267 msecs_to_jiffies(mhi_cntrl->timeout_ms));
1268 if (!ret || mhi_chan->ccs != MHI_EV_CC_SUCCESS)
1269 dev_err(dev,
1270 "Failed to receive cmd completion, still resetting\n");
1271
1272 error_invalid_state:
1273 if (!mhi_chan->offload_ch) {
1274 mhi_reset_chan(mhi_cntrl, mhi_chan);
1275 mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
1276 }
1277 dev_dbg(dev, "chan:%d successfully resetted\n", mhi_chan->chan);
1278 mutex_unlock(&mhi_chan->mutex);
1279 }
1280
1281 int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,
1282 struct mhi_chan *mhi_chan)
1283 {
1284 int ret = 0;
1285 struct device *dev = &mhi_cntrl->mhi_dev->dev;
1286
1287 dev_dbg(dev, "Preparing channel: %d\n", mhi_chan->chan);
1288
1289 if (!(BIT(mhi_cntrl->ee) & mhi_chan->ee_mask)) {
1290 dev_err(dev,
1291 "Current EE: %s Required EE Mask: 0x%x for chan: %s\n",
1292 TO_MHI_EXEC_STR(mhi_cntrl->ee), mhi_chan->ee_mask,
1293 mhi_chan->name);
1294 return -ENOTCONN;
1295 }
1296
1297 mutex_lock(&mhi_chan->mutex);
1298
1299 /* If channel is not in disable state, do not allow it to start */
1300 if (mhi_chan->ch_state != MHI_CH_STATE_DISABLED) {
1301 ret = -EIO;
1302 dev_dbg(dev, "channel: %d is not in disabled state\n",
1303 mhi_chan->chan);
1304 goto error_init_chan;
1305 }
1306
1307 /* Check of client manages channel context for offload channels */
1308 if (!mhi_chan->offload_ch) {
1309 ret = mhi_init_chan_ctxt(mhi_cntrl, mhi_chan);
1310 if (ret)
1311 goto error_init_chan;
1312 }
1313
1314 reinit_completion(&mhi_chan->completion);
1315 read_lock_bh(&mhi_cntrl->pm_lock);
1316 if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
1317 read_unlock_bh(&mhi_cntrl->pm_lock);
1318 ret = -EIO;
1319 goto error_pm_state;
1320 }
1321
1322 mhi_cntrl->wake_toggle(mhi_cntrl);
1323 read_unlock_bh(&mhi_cntrl->pm_lock);
1324 mhi_cntrl->runtime_get(mhi_cntrl);
1325 mhi_cntrl->runtime_put(mhi_cntrl);
1326
1327 ret = mhi_send_cmd(mhi_cntrl, mhi_chan, MHI_CMD_START_CHAN);
1328 if (ret)
1329 goto error_pm_state;
1330
1331 ret = wait_for_completion_timeout(&mhi_chan->completion,
1332 msecs_to_jiffies(mhi_cntrl->timeout_ms));
1333 if (!ret || mhi_chan->ccs != MHI_EV_CC_SUCCESS) {
1334 ret = -EIO;
1335 goto error_pm_state;
1336 }
1337
1338 write_lock_irq(&mhi_chan->lock);
1339 mhi_chan->ch_state = MHI_CH_STATE_ENABLED;
1340 write_unlock_irq(&mhi_chan->lock);
1341
1342 /* Pre-allocate buffer for xfer ring */
1343 if (mhi_chan->pre_alloc) {
1344 int nr_el = get_nr_avail_ring_elements(mhi_cntrl,
1345 &mhi_chan->tre_ring);
1346 size_t len = mhi_cntrl->buffer_len;
1347
1348 while (nr_el--) {
1349 void *buf;
1350 struct mhi_buf_info info = { };
1351 buf = kmalloc(len, GFP_KERNEL);
1352 if (!buf) {
1353 ret = -ENOMEM;
1354 goto error_pre_alloc;
1355 }
1356
1357 /* Prepare transfer descriptors */
1358 info.v_addr = buf;
1359 info.cb_buf = buf;
1360 info.len = len;
1361 ret = mhi_gen_tre(mhi_cntrl, mhi_chan, &info, MHI_EOT);
1362 if (ret) {
1363 kfree(buf);
1364 goto error_pre_alloc;
1365 }
1366 }
1367
1368 read_lock_bh(&mhi_cntrl->pm_lock);
1369 if (MHI_DB_ACCESS_VALID(mhi_cntrl)) {
1370 read_lock_irq(&mhi_chan->lock);
1371 mhi_ring_chan_db(mhi_cntrl, mhi_chan);
1372 read_unlock_irq(&mhi_chan->lock);
1373 }
1374 read_unlock_bh(&mhi_cntrl->pm_lock);
1375 }
1376
1377 mutex_unlock(&mhi_chan->mutex);
1378
1379 dev_dbg(dev, "Chan: %d successfully moved to start state\n",
1380 mhi_chan->chan);
1381
1382 return 0;
1383
1384 error_pm_state:
1385 if (!mhi_chan->offload_ch)
1386 mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
1387
1388 error_init_chan:
1389 mutex_unlock(&mhi_chan->mutex);
1390
1391 return ret;
1392
1393 error_pre_alloc:
1394 mutex_unlock(&mhi_chan->mutex);
1395 __mhi_unprepare_channel(mhi_cntrl, mhi_chan);
1396
1397 return ret;
1398 }
1399
1400 static void mhi_mark_stale_events(struct mhi_controller *mhi_cntrl,
1401 struct mhi_event *mhi_event,
1402 struct mhi_event_ctxt *er_ctxt,
1403 int chan)
1404
1405 {
1406 struct mhi_tre *dev_rp, *local_rp;
1407 struct mhi_ring *ev_ring;
1408 struct device *dev = &mhi_cntrl->mhi_dev->dev;
1409 unsigned long flags;
1410
1411 dev_dbg(dev, "Marking all events for chan: %d as stale\n", chan);
1412
1413 ev_ring = &mhi_event->ring;
1414
1415 /* mark all stale events related to channel as STALE event */
1416 spin_lock_irqsave(&mhi_event->lock, flags);
1417 dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
1418
1419 local_rp = ev_ring->rp;
1420 while (dev_rp != local_rp) {
1421 if (MHI_TRE_GET_EV_TYPE(local_rp) == MHI_PKT_TYPE_TX_EVENT &&
1422 chan == MHI_TRE_GET_EV_CHID(local_rp))
1423 local_rp->dword[1] = MHI_TRE_EV_DWORD1(chan,
1424 MHI_PKT_TYPE_STALE_EVENT);
1425 local_rp++;
1426 if (local_rp == (ev_ring->base + ev_ring->len))
1427 local_rp = ev_ring->base;
1428 }
1429
1430 dev_dbg(dev, "Finished marking events as stale events\n");
1431 spin_unlock_irqrestore(&mhi_event->lock, flags);
1432 }
1433
1434 static void mhi_reset_data_chan(struct mhi_controller *mhi_cntrl,
1435 struct mhi_chan *mhi_chan)
1436 {
1437 struct mhi_ring *buf_ring, *tre_ring;
1438 struct mhi_result result;
1439
1440 /* Reset any pending buffers */
1441 buf_ring = &mhi_chan->buf_ring;
1442 tre_ring = &mhi_chan->tre_ring;
1443 result.transaction_status = -ENOTCONN;
1444 result.bytes_xferd = 0;
1445 while (tre_ring->rp != tre_ring->wp) {
1446 struct mhi_buf_info *buf_info = buf_ring->rp;
1447
1448 if (mhi_chan->dir == DMA_TO_DEVICE)
1449 atomic_dec(&mhi_cntrl->pending_pkts);
1450
1451 if (!buf_info->pre_mapped)
1452 mhi_cntrl->unmap_single(mhi_cntrl, buf_info);
1453
1454 mhi_del_ring_element(mhi_cntrl, buf_ring);
1455 mhi_del_ring_element(mhi_cntrl, tre_ring);
1456
1457 if (mhi_chan->pre_alloc) {
1458 kfree(buf_info->cb_buf);
1459 } else {
1460 result.buf_addr = buf_info->cb_buf;
1461 mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
1462 }
1463 }
1464 }
1465
1466 void mhi_reset_chan(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan)
1467 {
1468 struct mhi_event *mhi_event;
1469 struct mhi_event_ctxt *er_ctxt;
1470 int chan = mhi_chan->chan;
1471
1472 /* Nothing to reset, client doesn't queue buffers */
1473 if (mhi_chan->offload_ch)
1474 return;
1475
1476 read_lock_bh(&mhi_cntrl->pm_lock);
1477 mhi_event = &mhi_cntrl->mhi_event[mhi_chan->er_index];
1478 er_ctxt = &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_chan->er_index];
1479
1480 mhi_mark_stale_events(mhi_cntrl, mhi_event, er_ctxt, chan);
1481
1482 mhi_reset_data_chan(mhi_cntrl, mhi_chan);
1483
1484 read_unlock_bh(&mhi_cntrl->pm_lock);
1485 }
1486
1487 /* Move channel to start state */
1488 int mhi_prepare_for_transfer(struct mhi_device *mhi_dev)
1489 {
1490 int ret, dir;
1491 struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1492 struct mhi_chan *mhi_chan;
1493
1494 for (dir = 0; dir < 2; dir++) {
1495 mhi_chan = dir ? mhi_dev->dl_chan : mhi_dev->ul_chan;
1496 if (!mhi_chan)
1497 continue;
1498
1499 ret = mhi_prepare_channel(mhi_cntrl, mhi_chan);
1500 if (ret)
1501 goto error_open_chan;
1502 }
1503
1504 return 0;
1505
1506 error_open_chan:
1507 for (--dir; dir >= 0; dir--) {
1508 mhi_chan = dir ? mhi_dev->dl_chan : mhi_dev->ul_chan;
1509 if (!mhi_chan)
1510 continue;
1511
1512 __mhi_unprepare_channel(mhi_cntrl, mhi_chan);
1513 }
1514
1515 return ret;
1516 }
1517 EXPORT_SYMBOL_GPL(mhi_prepare_for_transfer);
1518
1519 void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev)
1520 {
1521 struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1522 struct mhi_chan *mhi_chan;
1523 int dir;
1524
1525 for (dir = 0; dir < 2; dir++) {
1526 mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
1527 if (!mhi_chan)
1528 continue;
1529
1530 __mhi_unprepare_channel(mhi_cntrl, mhi_chan);
1531 }
1532 }
1533 EXPORT_SYMBOL_GPL(mhi_unprepare_from_transfer);
1534
1535 int mhi_poll(struct mhi_device *mhi_dev, u32 budget)
1536 {
1537 struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1538 struct mhi_chan *mhi_chan = mhi_dev->dl_chan;
1539 struct mhi_event *mhi_event = &mhi_cntrl->mhi_event[mhi_chan->er_index];
1540 int ret;
1541
1542 spin_lock_bh(&mhi_event->lock);
1543 ret = mhi_event->process_event(mhi_cntrl, mhi_event, budget);
1544 spin_unlock_bh(&mhi_event->lock);
1545
1546 return ret;
1547 }
1548 EXPORT_SYMBOL_GPL(mhi_poll);
Linux with added FPC-III support