sh: guard cookie consistency across termination in the DMA driver
[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / dma / shdma.c
1 /*
2  * Renesas SuperH DMA Engine support
3  *
4  * base is drivers/dma/flsdma.c
5  *
6  * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
7  * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
8  * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
9  *
10  * This is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * - DMA of SuperH does not have Hardware DMA chain mode.
16  * - MAX DMA size is 16MB.
17  *
18  */
19
20 #include <linux/init.h>
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/dmaengine.h>
25 #include <linux/delay.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/platform_device.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/sh_dma.h>
30
31 #include "shdma.h"
32
33 /* DMA descriptor control */
34 enum sh_dmae_desc_status {
35         DESC_IDLE,
36         DESC_PREPARED,
37         DESC_SUBMITTED,
38         DESC_COMPLETED, /* completed, have to call callback */
39         DESC_WAITING,   /* callback called, waiting for ack / re-submit */
40 };
41
42 #define NR_DESCS_PER_CHANNEL 32
43 /* Default MEMCPY transfer size = 2^2 = 4 bytes */
44 #define LOG2_DEFAULT_XFER_SIZE  2
45
46 /* A bitmask with bits enough for enum sh_dmae_slave_chan_id */
47 static unsigned long sh_dmae_slave_used[BITS_TO_LONGS(SH_DMA_SLAVE_NUMBER)];
48
49 static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all);
50
51 static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg)
52 {
53         __raw_writel(data, sh_dc->base + reg / sizeof(u32));
54 }
55
56 static u32 sh_dmae_readl(struct sh_dmae_chan *sh_dc, u32 reg)
57 {
58         return __raw_readl(sh_dc->base + reg / sizeof(u32));
59 }
60
61 static u16 dmaor_read(struct sh_dmae_device *shdev)
62 {
63         return __raw_readw(shdev->chan_reg + DMAOR / sizeof(u32));
64 }
65
66 static void dmaor_write(struct sh_dmae_device *shdev, u16 data)
67 {
68         __raw_writew(data, shdev->chan_reg + DMAOR / sizeof(u32));
69 }
70
71 /*
72  * Reset DMA controller
73  *
74  * SH7780 has two DMAOR register
75  */
76 static void sh_dmae_ctl_stop(struct sh_dmae_device *shdev)
77 {
78         unsigned short dmaor = dmaor_read(shdev);
79
80         dmaor_write(shdev, dmaor & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME));
81 }
82
83 static int sh_dmae_rst(struct sh_dmae_device *shdev)
84 {
85         unsigned short dmaor;
86
87         sh_dmae_ctl_stop(shdev);
88         dmaor = dmaor_read(shdev) | shdev->pdata->dmaor_init;
89
90         dmaor_write(shdev, dmaor);
91         if (dmaor_read(shdev) & (DMAOR_AE | DMAOR_NMIF)) {
92                 pr_warning("dma-sh: Can't initialize DMAOR.\n");
93                 return -EINVAL;
94         }
95         return 0;
96 }
97
98 static bool dmae_is_busy(struct sh_dmae_chan *sh_chan)
99 {
100         u32 chcr = sh_dmae_readl(sh_chan, CHCR);
101
102         if ((chcr & (CHCR_DE | CHCR_TE)) == CHCR_DE)
103                 return true; /* working */
104
105         return false; /* waiting */
106 }
107
108 static unsigned int calc_xmit_shift(struct sh_dmae_chan *sh_chan, u32 chcr)
109 {
110         struct sh_dmae_device *shdev = container_of(sh_chan->common.device,
111                                                 struct sh_dmae_device, common);
112         struct sh_dmae_pdata *pdata = shdev->pdata;
113         int cnt = ((chcr & pdata->ts_low_mask) >> pdata->ts_low_shift) |
114                 ((chcr & pdata->ts_high_mask) >> pdata->ts_high_shift);
115
116         if (cnt >= pdata->ts_shift_num)
117                 cnt = 0;
118
119         return pdata->ts_shift[cnt];
120 }
121
122 static u32 log2size_to_chcr(struct sh_dmae_chan *sh_chan, int l2size)
123 {
124         struct sh_dmae_device *shdev = container_of(sh_chan->common.device,
125                                                 struct sh_dmae_device, common);
126         struct sh_dmae_pdata *pdata = shdev->pdata;
127         int i;
128
129         for (i = 0; i < pdata->ts_shift_num; i++)
130                 if (pdata->ts_shift[i] == l2size)
131                         break;
132
133         if (i == pdata->ts_shift_num)
134                 i = 0;
135
136         return ((i << pdata->ts_low_shift) & pdata->ts_low_mask) |
137                 ((i << pdata->ts_high_shift) & pdata->ts_high_mask);
138 }
139
140 static void dmae_set_reg(struct sh_dmae_chan *sh_chan, struct sh_dmae_regs *hw)
141 {
142         sh_dmae_writel(sh_chan, hw->sar, SAR);
143         sh_dmae_writel(sh_chan, hw->dar, DAR);
144         sh_dmae_writel(sh_chan, hw->tcr >> sh_chan->xmit_shift, TCR);
145 }
146
147 static void dmae_start(struct sh_dmae_chan *sh_chan)
148 {
149         u32 chcr = sh_dmae_readl(sh_chan, CHCR);
150
151         chcr |= CHCR_DE | CHCR_IE;
152         sh_dmae_writel(sh_chan, chcr & ~CHCR_TE, CHCR);
153 }
154
155 static void dmae_halt(struct sh_dmae_chan *sh_chan)
156 {
157         u32 chcr = sh_dmae_readl(sh_chan, CHCR);
158
159         chcr &= ~(CHCR_DE | CHCR_TE | CHCR_IE);
160         sh_dmae_writel(sh_chan, chcr, CHCR);
161 }
162
163 static void dmae_init(struct sh_dmae_chan *sh_chan)
164 {
165         /*
166          * Default configuration for dual address memory-memory transfer.
167          * 0x400 represents auto-request.
168          */
169         u32 chcr = DM_INC | SM_INC | 0x400 | log2size_to_chcr(sh_chan,
170                                                    LOG2_DEFAULT_XFER_SIZE);
171         sh_chan->xmit_shift = calc_xmit_shift(sh_chan, chcr);
172         sh_dmae_writel(sh_chan, chcr, CHCR);
173 }
174
175 static int dmae_set_chcr(struct sh_dmae_chan *sh_chan, u32 val)
176 {
177         /* When DMA was working, can not set data to CHCR */
178         if (dmae_is_busy(sh_chan))
179                 return -EBUSY;
180
181         sh_chan->xmit_shift = calc_xmit_shift(sh_chan, val);
182         sh_dmae_writel(sh_chan, val, CHCR);
183
184         return 0;
185 }
186
187 static int dmae_set_dmars(struct sh_dmae_chan *sh_chan, u16 val)
188 {
189         struct sh_dmae_device *shdev = container_of(sh_chan->common.device,
190                                                 struct sh_dmae_device, common);
191         struct sh_dmae_pdata *pdata = shdev->pdata;
192         const struct sh_dmae_channel *chan_pdata = &pdata->channel[sh_chan->id];
193         u16 __iomem *addr = shdev->dmars + chan_pdata->dmars / sizeof(u16);
194         int shift = chan_pdata->dmars_bit;
195
196         if (dmae_is_busy(sh_chan))
197                 return -EBUSY;
198
199         __raw_writew((__raw_readw(addr) & (0xff00 >> shift)) | (val << shift),
200                      addr);
201
202         return 0;
203 }
204
205 static dma_cookie_t sh_dmae_tx_submit(struct dma_async_tx_descriptor *tx)
206 {
207         struct sh_desc *desc = tx_to_sh_desc(tx), *chunk, *last = desc, *c;
208         struct sh_dmae_chan *sh_chan = to_sh_chan(tx->chan);
209         dma_async_tx_callback callback = tx->callback;
210         dma_cookie_t cookie;
211
212         spin_lock_bh(&sh_chan->desc_lock);
213
214         cookie = sh_chan->common.cookie;
215         cookie++;
216         if (cookie < 0)
217                 cookie = 1;
218
219         sh_chan->common.cookie = cookie;
220         tx->cookie = cookie;
221
222         /* Mark all chunks of this descriptor as submitted, move to the queue */
223         list_for_each_entry_safe(chunk, c, desc->node.prev, node) {
224                 /*
225                  * All chunks are on the global ld_free, so, we have to find
226                  * the end of the chain ourselves
227                  */
228                 if (chunk != desc && (chunk->mark == DESC_IDLE ||
229                                       chunk->async_tx.cookie > 0 ||
230                                       chunk->async_tx.cookie == -EBUSY ||
231                                       &chunk->node == &sh_chan->ld_free))
232                         break;
233                 chunk->mark = DESC_SUBMITTED;
234                 /* Callback goes to the last chunk */
235                 chunk->async_tx.callback = NULL;
236                 chunk->cookie = cookie;
237                 list_move_tail(&chunk->node, &sh_chan->ld_queue);
238                 last = chunk;
239         }
240
241         last->async_tx.callback = callback;
242         last->async_tx.callback_param = tx->callback_param;
243
244         dev_dbg(sh_chan->dev, "submit #%d@%p on %d: %x[%d] -> %x\n",
245                 tx->cookie, &last->async_tx, sh_chan->id,
246                 desc->hw.sar, desc->hw.tcr, desc->hw.dar);
247
248         spin_unlock_bh(&sh_chan->desc_lock);
249
250         return cookie;
251 }
252
253 /* Called with desc_lock held */
254 static struct sh_desc *sh_dmae_get_desc(struct sh_dmae_chan *sh_chan)
255 {
256         struct sh_desc *desc;
257
258         list_for_each_entry(desc, &sh_chan->ld_free, node)
259                 if (desc->mark != DESC_PREPARED) {
260                         BUG_ON(desc->mark != DESC_IDLE);
261                         list_del(&desc->node);
262                         return desc;
263                 }
264
265         return NULL;
266 }
267
268 static const struct sh_dmae_slave_config *sh_dmae_find_slave(
269         struct sh_dmae_chan *sh_chan, struct sh_dmae_slave *param)
270 {
271         struct dma_device *dma_dev = sh_chan->common.device;
272         struct sh_dmae_device *shdev = container_of(dma_dev,
273                                         struct sh_dmae_device, common);
274         struct sh_dmae_pdata *pdata = shdev->pdata;
275         int i;
276
277         if (param->slave_id >= SH_DMA_SLAVE_NUMBER)
278                 return NULL;
279
280         for (i = 0; i < pdata->slave_num; i++)
281                 if (pdata->slave[i].slave_id == param->slave_id)
282                         return pdata->slave + i;
283
284         return NULL;
285 }
286
287 static int sh_dmae_alloc_chan_resources(struct dma_chan *chan)
288 {
289         struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
290         struct sh_desc *desc;
291         struct sh_dmae_slave *param = chan->private;
292         int ret;
293
294         pm_runtime_get_sync(sh_chan->dev);
295
296         /*
297          * This relies on the guarantee from dmaengine that alloc_chan_resources
298          * never runs concurrently with itself or free_chan_resources.
299          */
300         if (param) {
301                 const struct sh_dmae_slave_config *cfg;
302
303                 cfg = sh_dmae_find_slave(sh_chan, param);
304                 if (!cfg) {
305                         ret = -EINVAL;
306                         goto efindslave;
307                 }
308
309                 if (test_and_set_bit(param->slave_id, sh_dmae_slave_used)) {
310                         ret = -EBUSY;
311                         goto etestused;
312                 }
313
314                 param->config = cfg;
315
316                 dmae_set_dmars(sh_chan, cfg->mid_rid);
317                 dmae_set_chcr(sh_chan, cfg->chcr);
318         } else if ((sh_dmae_readl(sh_chan, CHCR) & 0xf00) != 0x400) {
319                 dmae_init(sh_chan);
320         }
321
322         spin_lock_bh(&sh_chan->desc_lock);
323         while (sh_chan->descs_allocated < NR_DESCS_PER_CHANNEL) {
324                 spin_unlock_bh(&sh_chan->desc_lock);
325                 desc = kzalloc(sizeof(struct sh_desc), GFP_KERNEL);
326                 if (!desc) {
327                         spin_lock_bh(&sh_chan->desc_lock);
328                         break;
329                 }
330                 dma_async_tx_descriptor_init(&desc->async_tx,
331                                         &sh_chan->common);
332                 desc->async_tx.tx_submit = sh_dmae_tx_submit;
333                 desc->mark = DESC_IDLE;
334
335                 spin_lock_bh(&sh_chan->desc_lock);
336                 list_add(&desc->node, &sh_chan->ld_free);
337                 sh_chan->descs_allocated++;
338         }
339         spin_unlock_bh(&sh_chan->desc_lock);
340
341         if (!sh_chan->descs_allocated) {
342                 ret = -ENOMEM;
343                 goto edescalloc;
344         }
345
346         return sh_chan->descs_allocated;
347
348 edescalloc:
349         if (param)
350                 clear_bit(param->slave_id, sh_dmae_slave_used);
351 etestused:
352 efindslave:
353         pm_runtime_put(sh_chan->dev);
354         return ret;
355 }
356
357 /*
358  * sh_dma_free_chan_resources - Free all resources of the channel.
359  */
360 static void sh_dmae_free_chan_resources(struct dma_chan *chan)
361 {
362         struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
363         struct sh_desc *desc, *_desc;
364         LIST_HEAD(list);
365         int descs = sh_chan->descs_allocated;
366
367         dmae_halt(sh_chan);
368
369         /* Prepared and not submitted descriptors can still be on the queue */
370         if (!list_empty(&sh_chan->ld_queue))
371                 sh_dmae_chan_ld_cleanup(sh_chan, true);
372
373         if (chan->private) {
374                 /* The caller is holding dma_list_mutex */
375                 struct sh_dmae_slave *param = chan->private;
376                 clear_bit(param->slave_id, sh_dmae_slave_used);
377         }
378
379         spin_lock_bh(&sh_chan->desc_lock);
380
381         list_splice_init(&sh_chan->ld_free, &list);
382         sh_chan->descs_allocated = 0;
383
384         spin_unlock_bh(&sh_chan->desc_lock);
385
386         if (descs > 0)
387                 pm_runtime_put(sh_chan->dev);
388
389         list_for_each_entry_safe(desc, _desc, &list, node)
390                 kfree(desc);
391 }
392
393 /**
394  * sh_dmae_add_desc - get, set up and return one transfer descriptor
395  * @sh_chan:    DMA channel
396  * @flags:      DMA transfer flags
397  * @dest:       destination DMA address, incremented when direction equals
398  *              DMA_FROM_DEVICE or DMA_BIDIRECTIONAL
399  * @src:        source DMA address, incremented when direction equals
400  *              DMA_TO_DEVICE or DMA_BIDIRECTIONAL
401  * @len:        DMA transfer length
402  * @first:      if NULL, set to the current descriptor and cookie set to -EBUSY
403  * @direction:  needed for slave DMA to decide which address to keep constant,
404  *              equals DMA_BIDIRECTIONAL for MEMCPY
405  * Returns 0 or an error
406  * Locks: called with desc_lock held
407  */
408 static struct sh_desc *sh_dmae_add_desc(struct sh_dmae_chan *sh_chan,
409         unsigned long flags, dma_addr_t *dest, dma_addr_t *src, size_t *len,
410         struct sh_desc **first, enum dma_data_direction direction)
411 {
412         struct sh_desc *new;
413         size_t copy_size;
414
415         if (!*len)
416                 return NULL;
417
418         /* Allocate the link descriptor from the free list */
419         new = sh_dmae_get_desc(sh_chan);
420         if (!new) {
421                 dev_err(sh_chan->dev, "No free link descriptor available\n");
422                 return NULL;
423         }
424
425         copy_size = min(*len, (size_t)SH_DMA_TCR_MAX + 1);
426
427         new->hw.sar = *src;
428         new->hw.dar = *dest;
429         new->hw.tcr = copy_size;
430
431         if (!*first) {
432                 /* First desc */
433                 new->async_tx.cookie = -EBUSY;
434                 *first = new;
435         } else {
436                 /* Other desc - invisible to the user */
437                 new->async_tx.cookie = -EINVAL;
438         }
439
440         dev_dbg(sh_chan->dev,
441                 "chaining (%u/%u)@%x -> %x with %p, cookie %d, shift %d\n",
442                 copy_size, *len, *src, *dest, &new->async_tx,
443                 new->async_tx.cookie, sh_chan->xmit_shift);
444
445         new->mark = DESC_PREPARED;
446         new->async_tx.flags = flags;
447         new->direction = direction;
448
449         *len -= copy_size;
450         if (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE)
451                 *src += copy_size;
452         if (direction == DMA_BIDIRECTIONAL || direction == DMA_FROM_DEVICE)
453                 *dest += copy_size;
454
455         return new;
456 }
457
458 /*
459  * sh_dmae_prep_sg - prepare transfer descriptors from an SG list
460  *
461  * Common routine for public (MEMCPY) and slave DMA. The MEMCPY case is also
462  * converted to scatter-gather to guarantee consistent locking and a correct
463  * list manipulation. For slave DMA direction carries the usual meaning, and,
464  * logically, the SG list is RAM and the addr variable contains slave address,
465  * e.g., the FIFO I/O register. For MEMCPY direction equals DMA_BIDIRECTIONAL
466  * and the SG list contains only one element and points at the source buffer.
467  */
468 static struct dma_async_tx_descriptor *sh_dmae_prep_sg(struct sh_dmae_chan *sh_chan,
469         struct scatterlist *sgl, unsigned int sg_len, dma_addr_t *addr,
470         enum dma_data_direction direction, unsigned long flags)
471 {
472         struct scatterlist *sg;
473         struct sh_desc *first = NULL, *new = NULL /* compiler... */;
474         LIST_HEAD(tx_list);
475         int chunks = 0;
476         int i;
477
478         if (!sg_len)
479                 return NULL;
480
481         for_each_sg(sgl, sg, sg_len, i)
482                 chunks += (sg_dma_len(sg) + SH_DMA_TCR_MAX) /
483                         (SH_DMA_TCR_MAX + 1);
484
485         /* Have to lock the whole loop to protect against concurrent release */
486         spin_lock_bh(&sh_chan->desc_lock);
487
488         /*
489          * Chaining:
490          * first descriptor is what user is dealing with in all API calls, its
491          *      cookie is at first set to -EBUSY, at tx-submit to a positive
492          *      number
493          * if more than one chunk is needed further chunks have cookie = -EINVAL
494          * the last chunk, if not equal to the first, has cookie = -ENOSPC
495          * all chunks are linked onto the tx_list head with their .node heads
496          *      only during this function, then they are immediately spliced
497          *      back onto the free list in form of a chain
498          */
499         for_each_sg(sgl, sg, sg_len, i) {
500                 dma_addr_t sg_addr = sg_dma_address(sg);
501                 size_t len = sg_dma_len(sg);
502
503                 if (!len)
504                         goto err_get_desc;
505
506                 do {
507                         dev_dbg(sh_chan->dev, "Add SG #%d@%p[%d], dma %llx\n",
508                                 i, sg, len, (unsigned long long)sg_addr);
509
510                         if (direction == DMA_FROM_DEVICE)
511                                 new = sh_dmae_add_desc(sh_chan, flags,
512                                                 &sg_addr, addr, &len, &first,
513                                                 direction);
514                         else
515                                 new = sh_dmae_add_desc(sh_chan, flags,
516                                                 addr, &sg_addr, &len, &first,
517                                                 direction);
518                         if (!new)
519                                 goto err_get_desc;
520
521                         new->chunks = chunks--;
522                         list_add_tail(&new->node, &tx_list);
523                 } while (len);
524         }
525
526         if (new != first)
527                 new->async_tx.cookie = -ENOSPC;
528
529         /* Put them back on the free list, so, they don't get lost */
530         list_splice_tail(&tx_list, &sh_chan->ld_free);
531
532         spin_unlock_bh(&sh_chan->desc_lock);
533
534         return &first->async_tx;
535
536 err_get_desc:
537         list_for_each_entry(new, &tx_list, node)
538                 new->mark = DESC_IDLE;
539         list_splice(&tx_list, &sh_chan->ld_free);
540
541         spin_unlock_bh(&sh_chan->desc_lock);
542
543         return NULL;
544 }
545
546 static struct dma_async_tx_descriptor *sh_dmae_prep_memcpy(
547         struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src,
548         size_t len, unsigned long flags)
549 {
550         struct sh_dmae_chan *sh_chan;
551         struct scatterlist sg;
552
553         if (!chan || !len)
554                 return NULL;
555
556         chan->private = NULL;
557
558         sh_chan = to_sh_chan(chan);
559
560         sg_init_table(&sg, 1);
561         sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_src)), len,
562                     offset_in_page(dma_src));
563         sg_dma_address(&sg) = dma_src;
564         sg_dma_len(&sg) = len;
565
566         return sh_dmae_prep_sg(sh_chan, &sg, 1, &dma_dest, DMA_BIDIRECTIONAL,
567                                flags);
568 }
569
570 static struct dma_async_tx_descriptor *sh_dmae_prep_slave_sg(
571         struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len,
572         enum dma_data_direction direction, unsigned long flags)
573 {
574         struct sh_dmae_slave *param;
575         struct sh_dmae_chan *sh_chan;
576         dma_addr_t slave_addr;
577
578         if (!chan)
579                 return NULL;
580
581         sh_chan = to_sh_chan(chan);
582         param = chan->private;
583         slave_addr = param->config->addr;
584
585         /* Someone calling slave DMA on a public channel? */
586         if (!param || !sg_len) {
587                 dev_warn(sh_chan->dev, "%s: bad parameter: %p, %d, %d\n",
588                          __func__, param, sg_len, param ? param->slave_id : -1);
589                 return NULL;
590         }
591
592         /*
593          * if (param != NULL), this is a successfully requested slave channel,
594          * therefore param->config != NULL too.
595          */
596         return sh_dmae_prep_sg(sh_chan, sgl, sg_len, &slave_addr,
597                                direction, flags);
598 }
599
600 static int sh_dmae_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
601                            unsigned long arg)
602 {
603         struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
604
605         /* Only supports DMA_TERMINATE_ALL */
606         if (cmd != DMA_TERMINATE_ALL)
607                 return -ENXIO;
608
609         if (!chan)
610                 return -EINVAL;
611
612         dmae_halt(sh_chan);
613
614         spin_lock_bh(&sh_chan->desc_lock);
615         if (!list_empty(&sh_chan->ld_queue)) {
616                 /* Record partial transfer */
617                 struct sh_desc *desc = list_entry(sh_chan->ld_queue.next,
618                                                   struct sh_desc, node);
619                 desc->partial = (desc->hw.tcr - sh_dmae_readl(sh_chan, TCR)) <<
620                         sh_chan->xmit_shift;
621
622         }
623         spin_unlock_bh(&sh_chan->desc_lock);
624
625         sh_dmae_chan_ld_cleanup(sh_chan, true);
626
627         return 0;
628 }
629
630 static dma_async_tx_callback __ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
631 {
632         struct sh_desc *desc, *_desc;
633         /* Is the "exposed" head of a chain acked? */
634         bool head_acked = false;
635         dma_cookie_t cookie = 0;
636         dma_async_tx_callback callback = NULL;
637         void *param = NULL;
638
639         spin_lock_bh(&sh_chan->desc_lock);
640         list_for_each_entry_safe(desc, _desc, &sh_chan->ld_queue, node) {
641                 struct dma_async_tx_descriptor *tx = &desc->async_tx;
642
643                 BUG_ON(tx->cookie > 0 && tx->cookie != desc->cookie);
644                 BUG_ON(desc->mark != DESC_SUBMITTED &&
645                        desc->mark != DESC_COMPLETED &&
646                        desc->mark != DESC_WAITING);
647
648                 /*
649                  * queue is ordered, and we use this loop to (1) clean up all
650                  * completed descriptors, and to (2) update descriptor flags of
651                  * any chunks in a (partially) completed chain
652                  */
653                 if (!all && desc->mark == DESC_SUBMITTED &&
654                     desc->cookie != cookie)
655                         break;
656
657                 if (tx->cookie > 0)
658                         cookie = tx->cookie;
659
660                 if (desc->mark == DESC_COMPLETED && desc->chunks == 1) {
661                         if (sh_chan->completed_cookie != desc->cookie - 1)
662                                 dev_dbg(sh_chan->dev,
663                                         "Completing cookie %d, expected %d\n",
664                                         desc->cookie,
665                                         sh_chan->completed_cookie + 1);
666                         sh_chan->completed_cookie = desc->cookie;
667                 }
668
669                 /* Call callback on the last chunk */
670                 if (desc->mark == DESC_COMPLETED && tx->callback) {
671                         desc->mark = DESC_WAITING;
672                         callback = tx->callback;
673                         param = tx->callback_param;
674                         dev_dbg(sh_chan->dev, "descriptor #%d@%p on %d callback\n",
675                                 tx->cookie, tx, sh_chan->id);
676                         BUG_ON(desc->chunks != 1);
677                         break;
678                 }
679
680                 if (tx->cookie > 0 || tx->cookie == -EBUSY) {
681                         if (desc->mark == DESC_COMPLETED) {
682                                 BUG_ON(tx->cookie < 0);
683                                 desc->mark = DESC_WAITING;
684                         }
685                         head_acked = async_tx_test_ack(tx);
686                 } else {
687                         switch (desc->mark) {
688                         case DESC_COMPLETED:
689                                 desc->mark = DESC_WAITING;
690                                 /* Fall through */
691                         case DESC_WAITING:
692                                 if (head_acked)
693                                         async_tx_ack(&desc->async_tx);
694                         }
695                 }
696
697                 dev_dbg(sh_chan->dev, "descriptor %p #%d completed.\n",
698                         tx, tx->cookie);
699
700                 if (((desc->mark == DESC_COMPLETED ||
701                       desc->mark == DESC_WAITING) &&
702                      async_tx_test_ack(&desc->async_tx)) || all) {
703                         /* Remove from ld_queue list */
704                         desc->mark = DESC_IDLE;
705                         list_move(&desc->node, &sh_chan->ld_free);
706                 }
707         }
708         spin_unlock_bh(&sh_chan->desc_lock);
709
710         if (callback)
711                 callback(param);
712
713         return callback;
714 }
715
716 /*
717  * sh_chan_ld_cleanup - Clean up link descriptors
718  *
719  * This function cleans up the ld_queue of DMA channel.
720  */
721 static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
722 {
723         while (__ld_cleanup(sh_chan, all))
724                 ;
725
726         if (all)
727                 /* Terminating - forgive uncompleted cookies */
728                 sh_chan->completed_cookie = sh_chan->common.cookie;
729 }
730
731 static void sh_chan_xfer_ld_queue(struct sh_dmae_chan *sh_chan)
732 {
733         struct sh_desc *desc;
734
735         spin_lock_bh(&sh_chan->desc_lock);
736         /* DMA work check */
737         if (dmae_is_busy(sh_chan)) {
738                 spin_unlock_bh(&sh_chan->desc_lock);
739                 return;
740         }
741
742         /* Find the first not transferred desciptor */
743         list_for_each_entry(desc, &sh_chan->ld_queue, node)
744                 if (desc->mark == DESC_SUBMITTED) {
745                         dev_dbg(sh_chan->dev, "Queue #%d to %d: %u@%x -> %x\n",
746                                 desc->async_tx.cookie, sh_chan->id,
747                                 desc->hw.tcr, desc->hw.sar, desc->hw.dar);
748                         /* Get the ld start address from ld_queue */
749                         dmae_set_reg(sh_chan, &desc->hw);
750                         dmae_start(sh_chan);
751                         break;
752                 }
753
754         spin_unlock_bh(&sh_chan->desc_lock);
755 }
756
757 static void sh_dmae_memcpy_issue_pending(struct dma_chan *chan)
758 {
759         struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
760         sh_chan_xfer_ld_queue(sh_chan);
761 }
762
763 static enum dma_status sh_dmae_tx_status(struct dma_chan *chan,
764                                         dma_cookie_t cookie,
765                                         struct dma_tx_state *txstate)
766 {
767         struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
768         dma_cookie_t last_used;
769         dma_cookie_t last_complete;
770         enum dma_status status;
771
772         sh_dmae_chan_ld_cleanup(sh_chan, false);
773
774         last_used = chan->cookie;
775         last_complete = sh_chan->completed_cookie;
776         BUG_ON(last_complete < 0);
777         dma_set_tx_state(txstate, last_complete, last_used, 0);
778
779         spin_lock_bh(&sh_chan->desc_lock);
780
781         status = dma_async_is_complete(cookie, last_complete, last_used);
782
783         /*
784          * If we don't find cookie on the queue, it has been aborted and we have
785          * to report error
786          */
787         if (status != DMA_SUCCESS) {
788                 struct sh_desc *desc;
789                 status = DMA_ERROR;
790                 list_for_each_entry(desc, &sh_chan->ld_queue, node)
791                         if (desc->cookie == cookie) {
792                                 status = DMA_IN_PROGRESS;
793                                 break;
794                         }
795         }
796
797         spin_unlock_bh(&sh_chan->desc_lock);
798
799         return status;
800 }
801
802 static irqreturn_t sh_dmae_interrupt(int irq, void *data)
803 {
804         irqreturn_t ret = IRQ_NONE;
805         struct sh_dmae_chan *sh_chan = (struct sh_dmae_chan *)data;
806         u32 chcr = sh_dmae_readl(sh_chan, CHCR);
807
808         if (chcr & CHCR_TE) {
809                 /* DMA stop */
810                 dmae_halt(sh_chan);
811
812                 ret = IRQ_HANDLED;
813                 tasklet_schedule(&sh_chan->tasklet);
814         }
815
816         return ret;
817 }
818
819 #if defined(CONFIG_CPU_SH4)
820 static irqreturn_t sh_dmae_err(int irq, void *data)
821 {
822         struct sh_dmae_device *shdev = (struct sh_dmae_device *)data;
823         int i;
824
825         /* halt the dma controller */
826         sh_dmae_ctl_stop(shdev);
827
828         /* We cannot detect, which channel caused the error, have to reset all */
829         for (i = 0; i < SH_DMAC_MAX_CHANNELS; i++) {
830                 struct sh_dmae_chan *sh_chan = shdev->chan[i];
831                 if (sh_chan) {
832                         struct sh_desc *desc;
833                         /* Stop the channel */
834                         dmae_halt(sh_chan);
835                         /* Complete all  */
836                         list_for_each_entry(desc, &sh_chan->ld_queue, node) {
837                                 struct dma_async_tx_descriptor *tx = &desc->async_tx;
838                                 desc->mark = DESC_IDLE;
839                                 if (tx->callback)
840                                         tx->callback(tx->callback_param);
841                         }
842                         list_splice_init(&sh_chan->ld_queue, &sh_chan->ld_free);
843                 }
844         }
845         sh_dmae_rst(shdev);
846
847         return IRQ_HANDLED;
848 }
849 #endif
850
851 static void dmae_do_tasklet(unsigned long data)
852 {
853         struct sh_dmae_chan *sh_chan = (struct sh_dmae_chan *)data;
854         struct sh_desc *desc;
855         u32 sar_buf = sh_dmae_readl(sh_chan, SAR);
856         u32 dar_buf = sh_dmae_readl(sh_chan, DAR);
857
858         spin_lock(&sh_chan->desc_lock);
859         list_for_each_entry(desc, &sh_chan->ld_queue, node) {
860                 if (desc->mark == DESC_SUBMITTED &&
861                     ((desc->direction == DMA_FROM_DEVICE &&
862                       (desc->hw.dar + desc->hw.tcr) == dar_buf) ||
863                      (desc->hw.sar + desc->hw.tcr) == sar_buf)) {
864                         dev_dbg(sh_chan->dev, "done #%d@%p dst %u\n",
865                                 desc->async_tx.cookie, &desc->async_tx,
866                                 desc->hw.dar);
867                         desc->mark = DESC_COMPLETED;
868                         break;
869                 }
870         }
871         spin_unlock(&sh_chan->desc_lock);
872
873         /* Next desc */
874         sh_chan_xfer_ld_queue(sh_chan);
875         sh_dmae_chan_ld_cleanup(sh_chan, false);
876 }
877
878 static int __devinit sh_dmae_chan_probe(struct sh_dmae_device *shdev, int id,
879                                         int irq, unsigned long flags)
880 {
881         int err;
882         const struct sh_dmae_channel *chan_pdata = &shdev->pdata->channel[id];
883         struct platform_device *pdev = to_platform_device(shdev->common.dev);
884         struct sh_dmae_chan *new_sh_chan;
885
886         /* alloc channel */
887         new_sh_chan = kzalloc(sizeof(struct sh_dmae_chan), GFP_KERNEL);
888         if (!new_sh_chan) {
889                 dev_err(shdev->common.dev,
890                         "No free memory for allocating dma channels!\n");
891                 return -ENOMEM;
892         }
893
894         /* copy struct dma_device */
895         new_sh_chan->common.device = &shdev->common;
896
897         new_sh_chan->dev = shdev->common.dev;
898         new_sh_chan->id = id;
899         new_sh_chan->irq = irq;
900         new_sh_chan->base = shdev->chan_reg + chan_pdata->offset / sizeof(u32);
901
902         /* Init DMA tasklet */
903         tasklet_init(&new_sh_chan->tasklet, dmae_do_tasklet,
904                         (unsigned long)new_sh_chan);
905
906         /* Init the channel */
907         dmae_init(new_sh_chan);
908
909         spin_lock_init(&new_sh_chan->desc_lock);
910
911         /* Init descripter manage list */
912         INIT_LIST_HEAD(&new_sh_chan->ld_queue);
913         INIT_LIST_HEAD(&new_sh_chan->ld_free);
914
915         /* Add the channel to DMA device channel list */
916         list_add_tail(&new_sh_chan->common.device_node,
917                         &shdev->common.channels);
918         shdev->common.chancnt++;
919
920         if (pdev->id >= 0)
921                 snprintf(new_sh_chan->dev_id, sizeof(new_sh_chan->dev_id),
922                          "sh-dmae%d.%d", pdev->id, new_sh_chan->id);
923         else
924                 snprintf(new_sh_chan->dev_id, sizeof(new_sh_chan->dev_id),
925                          "sh-dma%d", new_sh_chan->id);
926
927         /* set up channel irq */
928         err = request_irq(irq, &sh_dmae_interrupt, flags,
929                           new_sh_chan->dev_id, new_sh_chan);
930         if (err) {
931                 dev_err(shdev->common.dev, "DMA channel %d request_irq error "
932                         "with return %d\n", id, err);
933                 goto err_no_irq;
934         }
935
936         shdev->chan[id] = new_sh_chan;
937         return 0;
938
939 err_no_irq:
940         /* remove from dmaengine device node */
941         list_del(&new_sh_chan->common.device_node);
942         kfree(new_sh_chan);
943         return err;
944 }
945
946 static void sh_dmae_chan_remove(struct sh_dmae_device *shdev)
947 {
948         int i;
949
950         for (i = shdev->common.chancnt - 1 ; i >= 0 ; i--) {
951                 if (shdev->chan[i]) {
952                         struct sh_dmae_chan *sh_chan = shdev->chan[i];
953
954                         free_irq(sh_chan->irq, sh_chan);
955
956                         list_del(&sh_chan->common.device_node);
957                         kfree(sh_chan);
958                         shdev->chan[i] = NULL;
959                 }
960         }
961         shdev->common.chancnt = 0;
962 }
963
964 static int __init sh_dmae_probe(struct platform_device *pdev)
965 {
966         struct sh_dmae_pdata *pdata = pdev->dev.platform_data;
967         unsigned long irqflags = IRQF_DISABLED,
968                 chan_flag[SH_DMAC_MAX_CHANNELS] = {};
969         int errirq, chan_irq[SH_DMAC_MAX_CHANNELS];
970         int err, i, irq_cnt = 0, irqres = 0;
971         struct sh_dmae_device *shdev;
972         struct resource *chan, *dmars, *errirq_res, *chanirq_res;
973
974         /* get platform data */
975         if (!pdata || !pdata->channel_num)
976                 return -ENODEV;
977
978         chan = platform_get_resource(pdev, IORESOURCE_MEM, 0);
979         /* DMARS area is optional, if absent, this controller cannot do slave DMA */
980         dmars = platform_get_resource(pdev, IORESOURCE_MEM, 1);
981         /*
982          * IRQ resources:
983          * 1. there always must be at least one IRQ IO-resource. On SH4 it is
984          *    the error IRQ, in which case it is the only IRQ in this resource:
985          *    start == end. If it is the only IRQ resource, all channels also
986          *    use the same IRQ.
987          * 2. DMA channel IRQ resources can be specified one per resource or in
988          *    ranges (start != end)
989          * 3. iff all events (channels and, optionally, error) on this
990          *    controller use the same IRQ, only one IRQ resource can be
991          *    specified, otherwise there must be one IRQ per channel, even if
992          *    some of them are equal
993          * 4. if all IRQs on this controller are equal or if some specific IRQs
994          *    specify IORESOURCE_IRQ_SHAREABLE in their resources, they will be
995          *    requested with the IRQF_SHARED flag
996          */
997         errirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
998         if (!chan || !errirq_res)
999                 return -ENODEV;
1000
1001         if (!request_mem_region(chan->start, resource_size(chan), pdev->name)) {
1002                 dev_err(&pdev->dev, "DMAC register region already claimed\n");
1003                 return -EBUSY;
1004         }
1005
1006         if (dmars && !request_mem_region(dmars->start, resource_size(dmars), pdev->name)) {
1007                 dev_err(&pdev->dev, "DMAC DMARS region already claimed\n");
1008                 err = -EBUSY;
1009                 goto ermrdmars;
1010         }
1011
1012         err = -ENOMEM;
1013         shdev = kzalloc(sizeof(struct sh_dmae_device), GFP_KERNEL);
1014         if (!shdev) {
1015                 dev_err(&pdev->dev, "Not enough memory\n");
1016                 goto ealloc;
1017         }
1018
1019         shdev->chan_reg = ioremap(chan->start, resource_size(chan));
1020         if (!shdev->chan_reg)
1021                 goto emapchan;
1022         if (dmars) {
1023                 shdev->dmars = ioremap(dmars->start, resource_size(dmars));
1024                 if (!shdev->dmars)
1025                         goto emapdmars;
1026         }
1027
1028         /* platform data */
1029         shdev->pdata = pdata;
1030
1031         pm_runtime_enable(&pdev->dev);
1032         pm_runtime_get_sync(&pdev->dev);
1033
1034         /* reset dma controller */
1035         err = sh_dmae_rst(shdev);
1036         if (err)
1037                 goto rst_err;
1038
1039         INIT_LIST_HEAD(&shdev->common.channels);
1040
1041         dma_cap_set(DMA_MEMCPY, shdev->common.cap_mask);
1042         if (dmars)
1043                 dma_cap_set(DMA_SLAVE, shdev->common.cap_mask);
1044
1045         shdev->common.device_alloc_chan_resources
1046                 = sh_dmae_alloc_chan_resources;
1047         shdev->common.device_free_chan_resources = sh_dmae_free_chan_resources;
1048         shdev->common.device_prep_dma_memcpy = sh_dmae_prep_memcpy;
1049         shdev->common.device_tx_status = sh_dmae_tx_status;
1050         shdev->common.device_issue_pending = sh_dmae_memcpy_issue_pending;
1051
1052         /* Compulsory for DMA_SLAVE fields */
1053         shdev->common.device_prep_slave_sg = sh_dmae_prep_slave_sg;
1054         shdev->common.device_control = sh_dmae_control;
1055
1056         shdev->common.dev = &pdev->dev;
1057         /* Default transfer size of 32 bytes requires 32-byte alignment */
1058         shdev->common.copy_align = LOG2_DEFAULT_XFER_SIZE;
1059
1060 #if defined(CONFIG_CPU_SH4)
1061         chanirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
1062
1063         if (!chanirq_res)
1064                 chanirq_res = errirq_res;
1065         else
1066                 irqres++;
1067
1068         if (chanirq_res == errirq_res ||
1069             (errirq_res->flags & IORESOURCE_BITS) == IORESOURCE_IRQ_SHAREABLE)
1070                 irqflags = IRQF_SHARED;
1071
1072         errirq = errirq_res->start;
1073
1074         err = request_irq(errirq, sh_dmae_err, irqflags,
1075                           "DMAC Address Error", shdev);
1076         if (err) {
1077                 dev_err(&pdev->dev,
1078                         "DMA failed requesting irq #%d, error %d\n",
1079                         errirq, err);
1080                 goto eirq_err;
1081         }
1082
1083 #else
1084         chanirq_res = errirq_res;
1085 #endif /* CONFIG_CPU_SH4 */
1086
1087         if (chanirq_res->start == chanirq_res->end &&
1088             !platform_get_resource(pdev, IORESOURCE_IRQ, 1)) {
1089                 /* Special case - all multiplexed */
1090                 for (; irq_cnt < pdata->channel_num; irq_cnt++) {
1091                         chan_irq[irq_cnt] = chanirq_res->start;
1092                         chan_flag[irq_cnt] = IRQF_SHARED;
1093                 }
1094         } else {
1095                 do {
1096                         for (i = chanirq_res->start; i <= chanirq_res->end; i++) {
1097                                 if ((errirq_res->flags & IORESOURCE_BITS) ==
1098                                     IORESOURCE_IRQ_SHAREABLE)
1099                                         chan_flag[irq_cnt] = IRQF_SHARED;
1100                                 else
1101                                         chan_flag[irq_cnt] = IRQF_DISABLED;
1102                                 dev_dbg(&pdev->dev,
1103                                         "Found IRQ %d for channel %d\n",
1104                                         i, irq_cnt);
1105                                 chan_irq[irq_cnt++] = i;
1106                         }
1107                         chanirq_res = platform_get_resource(pdev,
1108                                                 IORESOURCE_IRQ, ++irqres);
1109                 } while (irq_cnt < pdata->channel_num && chanirq_res);
1110         }
1111
1112         if (irq_cnt < pdata->channel_num)
1113                 goto eirqres;
1114
1115         /* Create DMA Channel */
1116         for (i = 0; i < pdata->channel_num; i++) {
1117                 err = sh_dmae_chan_probe(shdev, i, chan_irq[i], chan_flag[i]);
1118                 if (err)
1119                         goto chan_probe_err;
1120         }
1121
1122         pm_runtime_put(&pdev->dev);
1123
1124         platform_set_drvdata(pdev, shdev);
1125         dma_async_device_register(&shdev->common);
1126
1127         return err;
1128
1129 chan_probe_err:
1130         sh_dmae_chan_remove(shdev);
1131 eirqres:
1132 #if defined(CONFIG_CPU_SH4)
1133         free_irq(errirq, shdev);
1134 eirq_err:
1135 #endif
1136 rst_err:
1137         pm_runtime_put(&pdev->dev);
1138         if (dmars)
1139                 iounmap(shdev->dmars);
1140 emapdmars:
1141         iounmap(shdev->chan_reg);
1142 emapchan:
1143         kfree(shdev);
1144 ealloc:
1145         if (dmars)
1146                 release_mem_region(dmars->start, resource_size(dmars));
1147 ermrdmars:
1148         release_mem_region(chan->start, resource_size(chan));
1149
1150         return err;
1151 }
1152
1153 static int __exit sh_dmae_remove(struct platform_device *pdev)
1154 {
1155         struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
1156         struct resource *res;
1157         int errirq = platform_get_irq(pdev, 0);
1158
1159         dma_async_device_unregister(&shdev->common);
1160
1161         if (errirq > 0)
1162                 free_irq(errirq, shdev);
1163
1164         /* channel data remove */
1165         sh_dmae_chan_remove(shdev);
1166
1167         pm_runtime_disable(&pdev->dev);
1168
1169         if (shdev->dmars)
1170                 iounmap(shdev->dmars);
1171         iounmap(shdev->chan_reg);
1172
1173         kfree(shdev);
1174
1175         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1176         if (res)
1177                 release_mem_region(res->start, resource_size(res));
1178         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1179         if (res)
1180                 release_mem_region(res->start, resource_size(res));
1181
1182         return 0;
1183 }
1184
1185 static void sh_dmae_shutdown(struct platform_device *pdev)
1186 {
1187         struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
1188         sh_dmae_ctl_stop(shdev);
1189 }
1190
1191 static struct platform_driver sh_dmae_driver = {
1192         .remove         = __exit_p(sh_dmae_remove),
1193         .shutdown       = sh_dmae_shutdown,
1194         .driver = {
1195                 .owner  = THIS_MODULE,
1196                 .name   = "sh-dma-engine",
1197         },
1198 };
1199
1200 static int __init sh_dmae_init(void)
1201 {
1202         return platform_driver_probe(&sh_dmae_driver, sh_dmae_probe);
1203 }
1204 module_init(sh_dmae_init);
1205
1206 static void __exit sh_dmae_exit(void)
1207 {
1208         platform_driver_unregister(&sh_dmae_driver);
1209 }
1210 module_exit(sh_dmae_exit);
1211
1212 MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>");
1213 MODULE_DESCRIPTION("Renesas SH DMA Engine driver");
1214 MODULE_LICENSE("GPL");