xref: /linux/drivers/rapidio/devices/tsi721_dma.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * DMA Engine support for Tsi721 PCIExpress-to-SRIO bridge
3  *
4  * Copyright 2011 Integrated Device Technology, Inc.
5  * Alexandre Bounine <alexandre.bounine@idt.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License as published by the Free
9  * Software Foundation; either version 2 of the License, or (at your option)
10  * any later version.
11  *
12  * This program is distributed in the hope that it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  * more details.
16  *
17  * You should have received a copy of the GNU General Public License along with
18  * this program; if not, write to the Free Software Foundation, Inc., 59
19  * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
20  */
21 
22 #include <linux/io.h>
23 #include <linux/errno.h>
24 #include <linux/init.h>
25 #include <linux/ioport.h>
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/pci.h>
29 #include <linux/rio.h>
30 #include <linux/rio_drv.h>
31 #include <linux/dma-mapping.h>
32 #include <linux/interrupt.h>
33 #include <linux/kfifo.h>
34 #include <linux/delay.h>
35 
36 #include "tsi721.h"
37 
38 static inline struct tsi721_bdma_chan *to_tsi721_chan(struct dma_chan *chan)
39 {
40 	return container_of(chan, struct tsi721_bdma_chan, dchan);
41 }
42 
43 static inline struct tsi721_device *to_tsi721(struct dma_device *ddev)
44 {
45 	return container_of(ddev, struct rio_mport, dma)->priv;
46 }
47 
48 static inline
49 struct tsi721_tx_desc *to_tsi721_desc(struct dma_async_tx_descriptor *txd)
50 {
51 	return container_of(txd, struct tsi721_tx_desc, txd);
52 }
53 
54 static inline
55 struct tsi721_tx_desc *tsi721_dma_first_active(
56 				struct tsi721_bdma_chan *bdma_chan)
57 {
58 	return list_first_entry(&bdma_chan->active_list,
59 				struct tsi721_tx_desc, desc_node);
60 }
61 
62 static int tsi721_bdma_ch_init(struct tsi721_bdma_chan *bdma_chan)
63 {
64 	struct tsi721_dma_desc *bd_ptr;
65 	struct device *dev = bdma_chan->dchan.device->dev;
66 	u64		*sts_ptr;
67 	dma_addr_t	bd_phys;
68 	dma_addr_t	sts_phys;
69 	int		sts_size;
70 	int		bd_num = bdma_chan->bd_num;
71 
72 	dev_dbg(dev, "Init Block DMA Engine, CH%d\n", bdma_chan->id);
73 
74 	/* Allocate space for DMA descriptors */
75 	bd_ptr = dma_zalloc_coherent(dev,
76 				bd_num * sizeof(struct tsi721_dma_desc),
77 				&bd_phys, GFP_KERNEL);
78 	if (!bd_ptr)
79 		return -ENOMEM;
80 
81 	bdma_chan->bd_phys = bd_phys;
82 	bdma_chan->bd_base = bd_ptr;
83 
84 	dev_dbg(dev, "DMA descriptors @ %p (phys = %llx)\n",
85 		bd_ptr, (unsigned long long)bd_phys);
86 
87 	/* Allocate space for descriptor status FIFO */
88 	sts_size = (bd_num >= TSI721_DMA_MINSTSSZ) ?
89 					bd_num : TSI721_DMA_MINSTSSZ;
90 	sts_size = roundup_pow_of_two(sts_size);
91 	sts_ptr = dma_zalloc_coherent(dev,
92 				     sts_size * sizeof(struct tsi721_dma_sts),
93 				     &sts_phys, GFP_KERNEL);
94 	if (!sts_ptr) {
95 		/* Free space allocated for DMA descriptors */
96 		dma_free_coherent(dev,
97 				  bd_num * sizeof(struct tsi721_dma_desc),
98 				  bd_ptr, bd_phys);
99 		bdma_chan->bd_base = NULL;
100 		return -ENOMEM;
101 	}
102 
103 	bdma_chan->sts_phys = sts_phys;
104 	bdma_chan->sts_base = sts_ptr;
105 	bdma_chan->sts_size = sts_size;
106 
107 	dev_dbg(dev,
108 		"desc status FIFO @ %p (phys = %llx) size=0x%x\n",
109 		sts_ptr, (unsigned long long)sts_phys, sts_size);
110 
111 	/* Initialize DMA descriptors ring */
112 	bd_ptr[bd_num - 1].type_id = cpu_to_le32(DTYPE3 << 29);
113 	bd_ptr[bd_num - 1].next_lo = cpu_to_le32((u64)bd_phys &
114 						 TSI721_DMAC_DPTRL_MASK);
115 	bd_ptr[bd_num - 1].next_hi = cpu_to_le32((u64)bd_phys >> 32);
116 
117 	/* Setup DMA descriptor pointers */
118 	iowrite32(((u64)bd_phys >> 32),
119 		bdma_chan->regs + TSI721_DMAC_DPTRH);
120 	iowrite32(((u64)bd_phys & TSI721_DMAC_DPTRL_MASK),
121 		bdma_chan->regs + TSI721_DMAC_DPTRL);
122 
123 	/* Setup descriptor status FIFO */
124 	iowrite32(((u64)sts_phys >> 32),
125 		bdma_chan->regs + TSI721_DMAC_DSBH);
126 	iowrite32(((u64)sts_phys & TSI721_DMAC_DSBL_MASK),
127 		bdma_chan->regs + TSI721_DMAC_DSBL);
128 	iowrite32(TSI721_DMAC_DSSZ_SIZE(sts_size),
129 		bdma_chan->regs + TSI721_DMAC_DSSZ);
130 
131 	/* Clear interrupt bits */
132 	iowrite32(TSI721_DMAC_INT_ALL,
133 		bdma_chan->regs + TSI721_DMAC_INT);
134 
135 	ioread32(bdma_chan->regs + TSI721_DMAC_INT);
136 
137 	/* Toggle DMA channel initialization */
138 	iowrite32(TSI721_DMAC_CTL_INIT,	bdma_chan->regs + TSI721_DMAC_CTL);
139 	ioread32(bdma_chan->regs + TSI721_DMAC_CTL);
140 	bdma_chan->wr_count = bdma_chan->wr_count_next = 0;
141 	bdma_chan->sts_rdptr = 0;
142 	udelay(10);
143 
144 	return 0;
145 }
146 
147 static int tsi721_bdma_ch_free(struct tsi721_bdma_chan *bdma_chan)
148 {
149 	u32 ch_stat;
150 
151 	if (bdma_chan->bd_base == NULL)
152 		return 0;
153 
154 	/* Check if DMA channel still running */
155 	ch_stat = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
156 	if (ch_stat & TSI721_DMAC_STS_RUN)
157 		return -EFAULT;
158 
159 	/* Put DMA channel into init state */
160 	iowrite32(TSI721_DMAC_CTL_INIT,	bdma_chan->regs + TSI721_DMAC_CTL);
161 
162 	/* Free space allocated for DMA descriptors */
163 	dma_free_coherent(bdma_chan->dchan.device->dev,
164 		bdma_chan->bd_num * sizeof(struct tsi721_dma_desc),
165 		bdma_chan->bd_base, bdma_chan->bd_phys);
166 	bdma_chan->bd_base = NULL;
167 
168 	/* Free space allocated for status FIFO */
169 	dma_free_coherent(bdma_chan->dchan.device->dev,
170 		bdma_chan->sts_size * sizeof(struct tsi721_dma_sts),
171 		bdma_chan->sts_base, bdma_chan->sts_phys);
172 	bdma_chan->sts_base = NULL;
173 	return 0;
174 }
175 
176 static void
177 tsi721_bdma_interrupt_enable(struct tsi721_bdma_chan *bdma_chan, int enable)
178 {
179 	if (enable) {
180 		/* Clear pending BDMA channel interrupts */
181 		iowrite32(TSI721_DMAC_INT_ALL,
182 			bdma_chan->regs + TSI721_DMAC_INT);
183 		ioread32(bdma_chan->regs + TSI721_DMAC_INT);
184 		/* Enable BDMA channel interrupts */
185 		iowrite32(TSI721_DMAC_INT_ALL,
186 			bdma_chan->regs + TSI721_DMAC_INTE);
187 	} else {
188 		/* Disable BDMA channel interrupts */
189 		iowrite32(0, bdma_chan->regs + TSI721_DMAC_INTE);
190 		/* Clear pending BDMA channel interrupts */
191 		iowrite32(TSI721_DMAC_INT_ALL,
192 			bdma_chan->regs + TSI721_DMAC_INT);
193 	}
194 
195 }
196 
197 static bool tsi721_dma_is_idle(struct tsi721_bdma_chan *bdma_chan)
198 {
199 	u32 sts;
200 
201 	sts = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
202 	return ((sts & TSI721_DMAC_STS_RUN) == 0);
203 }
204 
205 void tsi721_bdma_handler(struct tsi721_bdma_chan *bdma_chan)
206 {
207 	/* Disable BDMA channel interrupts */
208 	iowrite32(0, bdma_chan->regs + TSI721_DMAC_INTE);
209 
210 	tasklet_schedule(&bdma_chan->tasklet);
211 }
212 
213 #ifdef CONFIG_PCI_MSI
214 /**
215  * tsi721_omsg_msix - MSI-X interrupt handler for BDMA channels
216  * @irq: Linux interrupt number
217  * @ptr: Pointer to interrupt-specific data (BDMA channel structure)
218  *
219  * Handles BDMA channel interrupts signaled using MSI-X.
220  */
221 static irqreturn_t tsi721_bdma_msix(int irq, void *ptr)
222 {
223 	struct tsi721_bdma_chan *bdma_chan = ptr;
224 
225 	tsi721_bdma_handler(bdma_chan);
226 	return IRQ_HANDLED;
227 }
228 #endif /* CONFIG_PCI_MSI */
229 
230 /* Must be called with the spinlock held */
231 static void tsi721_start_dma(struct tsi721_bdma_chan *bdma_chan)
232 {
233 	if (!tsi721_dma_is_idle(bdma_chan)) {
234 		dev_err(bdma_chan->dchan.device->dev,
235 			"BUG: Attempt to start non-idle channel\n");
236 		return;
237 	}
238 
239 	if (bdma_chan->wr_count == bdma_chan->wr_count_next) {
240 		dev_err(bdma_chan->dchan.device->dev,
241 			"BUG: Attempt to start DMA with no BDs ready\n");
242 		return;
243 	}
244 
245 	dev_dbg(bdma_chan->dchan.device->dev,
246 		"tx_chan: %p, chan: %d, regs: %p\n",
247 		bdma_chan, bdma_chan->dchan.chan_id, bdma_chan->regs);
248 
249 	iowrite32(bdma_chan->wr_count_next,
250 		bdma_chan->regs + TSI721_DMAC_DWRCNT);
251 	ioread32(bdma_chan->regs + TSI721_DMAC_DWRCNT);
252 
253 	bdma_chan->wr_count = bdma_chan->wr_count_next;
254 }
255 
256 static void tsi721_desc_put(struct tsi721_bdma_chan *bdma_chan,
257 			    struct tsi721_tx_desc *desc)
258 {
259 	dev_dbg(bdma_chan->dchan.device->dev,
260 		"Put desc: %p into free list\n", desc);
261 
262 	if (desc) {
263 		spin_lock_bh(&bdma_chan->lock);
264 		list_splice_init(&desc->tx_list, &bdma_chan->free_list);
265 		list_add(&desc->desc_node, &bdma_chan->free_list);
266 		bdma_chan->wr_count_next = bdma_chan->wr_count;
267 		spin_unlock_bh(&bdma_chan->lock);
268 	}
269 }
270 
271 static
272 struct tsi721_tx_desc *tsi721_desc_get(struct tsi721_bdma_chan *bdma_chan)
273 {
274 	struct tsi721_tx_desc *tx_desc, *_tx_desc;
275 	struct tsi721_tx_desc *ret = NULL;
276 	int i;
277 
278 	spin_lock_bh(&bdma_chan->lock);
279 	list_for_each_entry_safe(tx_desc, _tx_desc,
280 				 &bdma_chan->free_list, desc_node) {
281 		if (async_tx_test_ack(&tx_desc->txd)) {
282 			list_del(&tx_desc->desc_node);
283 			ret = tx_desc;
284 			break;
285 		}
286 		dev_dbg(bdma_chan->dchan.device->dev,
287 			"desc %p not ACKed\n", tx_desc);
288 	}
289 
290 	i = bdma_chan->wr_count_next % bdma_chan->bd_num;
291 	if (i == bdma_chan->bd_num - 1) {
292 		i = 0;
293 		bdma_chan->wr_count_next++; /* skip link descriptor */
294 	}
295 
296 	bdma_chan->wr_count_next++;
297 	tx_desc->txd.phys = bdma_chan->bd_phys +
298 				i * sizeof(struct tsi721_dma_desc);
299 	tx_desc->hw_desc = &((struct tsi721_dma_desc *)bdma_chan->bd_base)[i];
300 
301 	spin_unlock_bh(&bdma_chan->lock);
302 
303 	return ret;
304 }
305 
306 static int
307 tsi721_fill_desc(struct tsi721_bdma_chan *bdma_chan,
308 	struct tsi721_tx_desc *desc, struct scatterlist *sg,
309 	enum dma_rtype rtype, u32 sys_size)
310 {
311 	struct tsi721_dma_desc *bd_ptr = desc->hw_desc;
312 	u64 rio_addr;
313 
314 	if (sg_dma_len(sg) > TSI721_DMAD_BCOUNT1 + 1) {
315 		dev_err(bdma_chan->dchan.device->dev,
316 			"SG element is too large\n");
317 		return -EINVAL;
318 	}
319 
320 	dev_dbg(bdma_chan->dchan.device->dev,
321 		"desc: 0x%llx, addr: 0x%llx len: 0x%x\n",
322 		(u64)desc->txd.phys, (unsigned long long)sg_dma_address(sg),
323 		sg_dma_len(sg));
324 
325 	dev_dbg(bdma_chan->dchan.device->dev,
326 		"bd_ptr = %p did=%d raddr=0x%llx\n",
327 		bd_ptr, desc->destid, desc->rio_addr);
328 
329 	/* Initialize DMA descriptor */
330 	bd_ptr->type_id = cpu_to_le32((DTYPE1 << 29) |
331 					(rtype << 19) | desc->destid);
332 	if (desc->interrupt)
333 		bd_ptr->type_id |= cpu_to_le32(TSI721_DMAD_IOF);
334 	bd_ptr->bcount = cpu_to_le32(((desc->rio_addr & 0x3) << 30) |
335 					(sys_size << 26) | sg_dma_len(sg));
336 	rio_addr = (desc->rio_addr >> 2) |
337 				((u64)(desc->rio_addr_u & 0x3) << 62);
338 	bd_ptr->raddr_lo = cpu_to_le32(rio_addr & 0xffffffff);
339 	bd_ptr->raddr_hi = cpu_to_le32(rio_addr >> 32);
340 	bd_ptr->t1.bufptr_lo = cpu_to_le32(
341 					(u64)sg_dma_address(sg) & 0xffffffff);
342 	bd_ptr->t1.bufptr_hi = cpu_to_le32((u64)sg_dma_address(sg) >> 32);
343 	bd_ptr->t1.s_dist = 0;
344 	bd_ptr->t1.s_size = 0;
345 
346 	return 0;
347 }
348 
349 static void tsi721_dma_chain_complete(struct tsi721_bdma_chan *bdma_chan,
350 				      struct tsi721_tx_desc *desc)
351 {
352 	struct dma_async_tx_descriptor *txd = &desc->txd;
353 	dma_async_tx_callback callback = txd->callback;
354 	void *param = txd->callback_param;
355 
356 	list_splice_init(&desc->tx_list, &bdma_chan->free_list);
357 	list_move(&desc->desc_node, &bdma_chan->free_list);
358 	bdma_chan->completed_cookie = txd->cookie;
359 
360 	if (callback)
361 		callback(param);
362 }
363 
364 static void tsi721_dma_complete_all(struct tsi721_bdma_chan *bdma_chan)
365 {
366 	struct tsi721_tx_desc *desc, *_d;
367 	LIST_HEAD(list);
368 
369 	BUG_ON(!tsi721_dma_is_idle(bdma_chan));
370 
371 	if (!list_empty(&bdma_chan->queue))
372 		tsi721_start_dma(bdma_chan);
373 
374 	list_splice_init(&bdma_chan->active_list, &list);
375 	list_splice_init(&bdma_chan->queue, &bdma_chan->active_list);
376 
377 	list_for_each_entry_safe(desc, _d, &list, desc_node)
378 		tsi721_dma_chain_complete(bdma_chan, desc);
379 }
380 
381 static void tsi721_clr_stat(struct tsi721_bdma_chan *bdma_chan)
382 {
383 	u32 srd_ptr;
384 	u64 *sts_ptr;
385 	int i, j;
386 
387 	/* Check and clear descriptor status FIFO entries */
388 	srd_ptr = bdma_chan->sts_rdptr;
389 	sts_ptr = bdma_chan->sts_base;
390 	j = srd_ptr * 8;
391 	while (sts_ptr[j]) {
392 		for (i = 0; i < 8 && sts_ptr[j]; i++, j++)
393 			sts_ptr[j] = 0;
394 
395 		++srd_ptr;
396 		srd_ptr %= bdma_chan->sts_size;
397 		j = srd_ptr * 8;
398 	}
399 
400 	iowrite32(srd_ptr, bdma_chan->regs + TSI721_DMAC_DSRP);
401 	bdma_chan->sts_rdptr = srd_ptr;
402 }
403 
404 static void tsi721_advance_work(struct tsi721_bdma_chan *bdma_chan)
405 {
406 	if (list_empty(&bdma_chan->active_list) ||
407 		list_is_singular(&bdma_chan->active_list)) {
408 		dev_dbg(bdma_chan->dchan.device->dev,
409 			"%s: Active_list empty\n", __func__);
410 		tsi721_dma_complete_all(bdma_chan);
411 	} else {
412 		dev_dbg(bdma_chan->dchan.device->dev,
413 			"%s: Active_list NOT empty\n", __func__);
414 		tsi721_dma_chain_complete(bdma_chan,
415 					tsi721_dma_first_active(bdma_chan));
416 		tsi721_start_dma(bdma_chan);
417 	}
418 }
419 
420 static void tsi721_dma_tasklet(unsigned long data)
421 {
422 	struct tsi721_bdma_chan *bdma_chan = (struct tsi721_bdma_chan *)data;
423 	u32 dmac_int, dmac_sts;
424 
425 	dmac_int = ioread32(bdma_chan->regs + TSI721_DMAC_INT);
426 	dev_dbg(bdma_chan->dchan.device->dev, "%s: DMAC%d_INT = 0x%x\n",
427 		__func__, bdma_chan->id, dmac_int);
428 	/* Clear channel interrupts */
429 	iowrite32(dmac_int, bdma_chan->regs + TSI721_DMAC_INT);
430 
431 	if (dmac_int & TSI721_DMAC_INT_ERR) {
432 		dmac_sts = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
433 		dev_err(bdma_chan->dchan.device->dev,
434 			"%s: DMA ERROR - DMAC%d_STS = 0x%x\n",
435 			__func__, bdma_chan->id, dmac_sts);
436 	}
437 
438 	if (dmac_int & TSI721_DMAC_INT_STFULL) {
439 		dev_err(bdma_chan->dchan.device->dev,
440 			"%s: DMAC%d descriptor status FIFO is full\n",
441 			__func__, bdma_chan->id);
442 	}
443 
444 	if (dmac_int & (TSI721_DMAC_INT_DONE | TSI721_DMAC_INT_IOFDONE)) {
445 		tsi721_clr_stat(bdma_chan);
446 		spin_lock(&bdma_chan->lock);
447 		tsi721_advance_work(bdma_chan);
448 		spin_unlock(&bdma_chan->lock);
449 	}
450 
451 	/* Re-Enable BDMA channel interrupts */
452 	iowrite32(TSI721_DMAC_INT_ALL, bdma_chan->regs + TSI721_DMAC_INTE);
453 }
454 
455 static dma_cookie_t tsi721_tx_submit(struct dma_async_tx_descriptor *txd)
456 {
457 	struct tsi721_tx_desc *desc = to_tsi721_desc(txd);
458 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(txd->chan);
459 	dma_cookie_t cookie;
460 
461 	spin_lock_bh(&bdma_chan->lock);
462 
463 	cookie = txd->chan->cookie;
464 	if (++cookie < 0)
465 		cookie = 1;
466 	txd->chan->cookie = cookie;
467 	txd->cookie = cookie;
468 
469 	if (list_empty(&bdma_chan->active_list)) {
470 		list_add_tail(&desc->desc_node, &bdma_chan->active_list);
471 		tsi721_start_dma(bdma_chan);
472 	} else {
473 		list_add_tail(&desc->desc_node, &bdma_chan->queue);
474 	}
475 
476 	spin_unlock_bh(&bdma_chan->lock);
477 	return cookie;
478 }
479 
480 static int tsi721_alloc_chan_resources(struct dma_chan *dchan)
481 {
482 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
483 #ifdef CONFIG_PCI_MSI
484 	struct tsi721_device *priv = to_tsi721(dchan->device);
485 #endif
486 	struct tsi721_tx_desc *desc = NULL;
487 	LIST_HEAD(tmp_list);
488 	int i;
489 	int rc;
490 
491 	if (bdma_chan->bd_base)
492 		return bdma_chan->bd_num - 1;
493 
494 	/* Initialize BDMA channel */
495 	if (tsi721_bdma_ch_init(bdma_chan)) {
496 		dev_err(dchan->device->dev, "Unable to initialize data DMA"
497 			" channel %d, aborting\n", bdma_chan->id);
498 		return -ENOMEM;
499 	}
500 
501 	/* Alocate matching number of logical descriptors */
502 	desc = kcalloc((bdma_chan->bd_num - 1), sizeof(struct tsi721_tx_desc),
503 			GFP_KERNEL);
504 	if (!desc) {
505 		dev_err(dchan->device->dev,
506 			"Failed to allocate logical descriptors\n");
507 		rc = -ENOMEM;
508 		goto err_out;
509 	}
510 
511 	bdma_chan->tx_desc = desc;
512 
513 	for (i = 0; i < bdma_chan->bd_num - 1; i++) {
514 		dma_async_tx_descriptor_init(&desc[i].txd, dchan);
515 		desc[i].txd.tx_submit = tsi721_tx_submit;
516 		desc[i].txd.flags = DMA_CTRL_ACK;
517 		INIT_LIST_HEAD(&desc[i].tx_list);
518 		list_add_tail(&desc[i].desc_node, &tmp_list);
519 	}
520 
521 	spin_lock_bh(&bdma_chan->lock);
522 	list_splice(&tmp_list, &bdma_chan->free_list);
523 	bdma_chan->completed_cookie = dchan->cookie = 1;
524 	spin_unlock_bh(&bdma_chan->lock);
525 
526 #ifdef CONFIG_PCI_MSI
527 	if (priv->flags & TSI721_USING_MSIX) {
528 		/* Request interrupt service if we are in MSI-X mode */
529 		rc = request_irq(
530 			priv->msix[TSI721_VECT_DMA0_DONE +
531 				   bdma_chan->id].vector,
532 			tsi721_bdma_msix, 0,
533 			priv->msix[TSI721_VECT_DMA0_DONE +
534 				   bdma_chan->id].irq_name,
535 			(void *)bdma_chan);
536 
537 		if (rc) {
538 			dev_dbg(dchan->device->dev,
539 				"Unable to allocate MSI-X interrupt for "
540 				"BDMA%d-DONE\n", bdma_chan->id);
541 			goto err_out;
542 		}
543 
544 		rc = request_irq(priv->msix[TSI721_VECT_DMA0_INT +
545 					    bdma_chan->id].vector,
546 				tsi721_bdma_msix, 0,
547 				priv->msix[TSI721_VECT_DMA0_INT +
548 					   bdma_chan->id].irq_name,
549 				(void *)bdma_chan);
550 
551 		if (rc)	{
552 			dev_dbg(dchan->device->dev,
553 				"Unable to allocate MSI-X interrupt for "
554 				"BDMA%d-INT\n", bdma_chan->id);
555 			free_irq(
556 				priv->msix[TSI721_VECT_DMA0_DONE +
557 					   bdma_chan->id].vector,
558 				(void *)bdma_chan);
559 			rc = -EIO;
560 			goto err_out;
561 		}
562 	}
563 #endif /* CONFIG_PCI_MSI */
564 
565 	tasklet_enable(&bdma_chan->tasklet);
566 	tsi721_bdma_interrupt_enable(bdma_chan, 1);
567 
568 	return bdma_chan->bd_num - 1;
569 
570 err_out:
571 	kfree(desc);
572 	tsi721_bdma_ch_free(bdma_chan);
573 	return rc;
574 }
575 
576 static void tsi721_free_chan_resources(struct dma_chan *dchan)
577 {
578 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
579 #ifdef CONFIG_PCI_MSI
580 	struct tsi721_device *priv = to_tsi721(dchan->device);
581 #endif
582 	LIST_HEAD(list);
583 
584 	dev_dbg(dchan->device->dev, "%s: Entry\n", __func__);
585 
586 	if (bdma_chan->bd_base == NULL)
587 		return;
588 
589 	BUG_ON(!list_empty(&bdma_chan->active_list));
590 	BUG_ON(!list_empty(&bdma_chan->queue));
591 
592 	tasklet_disable(&bdma_chan->tasklet);
593 
594 	spin_lock_bh(&bdma_chan->lock);
595 	list_splice_init(&bdma_chan->free_list, &list);
596 	spin_unlock_bh(&bdma_chan->lock);
597 
598 	tsi721_bdma_interrupt_enable(bdma_chan, 0);
599 
600 #ifdef CONFIG_PCI_MSI
601 	if (priv->flags & TSI721_USING_MSIX) {
602 		free_irq(priv->msix[TSI721_VECT_DMA0_DONE +
603 				    bdma_chan->id].vector, (void *)bdma_chan);
604 		free_irq(priv->msix[TSI721_VECT_DMA0_INT +
605 				    bdma_chan->id].vector, (void *)bdma_chan);
606 	}
607 #endif /* CONFIG_PCI_MSI */
608 
609 	tsi721_bdma_ch_free(bdma_chan);
610 	kfree(bdma_chan->tx_desc);
611 }
612 
613 static
614 enum dma_status tsi721_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
615 				 struct dma_tx_state *txstate)
616 {
617 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
618 	dma_cookie_t		last_used;
619 	dma_cookie_t		last_completed;
620 	int			ret;
621 
622 	spin_lock_bh(&bdma_chan->lock);
623 	last_completed = bdma_chan->completed_cookie;
624 	last_used = dchan->cookie;
625 	spin_unlock_bh(&bdma_chan->lock);
626 
627 	ret = dma_async_is_complete(cookie, last_completed, last_used);
628 
629 	dma_set_tx_state(txstate, last_completed, last_used, 0);
630 
631 	dev_dbg(dchan->device->dev,
632 		"%s: exit, ret: %d, last_completed: %d, last_used: %d\n",
633 		__func__, ret, last_completed, last_used);
634 
635 	return ret;
636 }
637 
638 static void tsi721_issue_pending(struct dma_chan *dchan)
639 {
640 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
641 
642 	dev_dbg(dchan->device->dev, "%s: Entry\n", __func__);
643 
644 	if (tsi721_dma_is_idle(bdma_chan)) {
645 		spin_lock_bh(&bdma_chan->lock);
646 		tsi721_advance_work(bdma_chan);
647 		spin_unlock_bh(&bdma_chan->lock);
648 	} else
649 		dev_dbg(dchan->device->dev,
650 			"%s: DMA channel still busy\n", __func__);
651 }
652 
653 static
654 struct dma_async_tx_descriptor *tsi721_prep_rio_sg(struct dma_chan *dchan,
655 			struct scatterlist *sgl, unsigned int sg_len,
656 			enum dma_transfer_direction dir, unsigned long flags,
657 			void *tinfo)
658 {
659 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
660 	struct tsi721_tx_desc *desc = NULL;
661 	struct tsi721_tx_desc *first = NULL;
662 	struct scatterlist *sg;
663 	struct rio_dma_ext *rext = tinfo;
664 	u64 rio_addr = rext->rio_addr; /* limited to 64-bit rio_addr for now */
665 	unsigned int i;
666 	u32 sys_size = dma_to_mport(dchan->device)->sys_size;
667 	enum dma_rtype rtype;
668 
669 	if (!sgl || !sg_len) {
670 		dev_err(dchan->device->dev, "%s: No SG list\n", __func__);
671 		return NULL;
672 	}
673 
674 	if (dir == DMA_DEV_TO_MEM)
675 		rtype = NREAD;
676 	else if (dir == DMA_MEM_TO_DEV) {
677 		switch (rext->wr_type) {
678 		case RDW_ALL_NWRITE:
679 			rtype = ALL_NWRITE;
680 			break;
681 		case RDW_ALL_NWRITE_R:
682 			rtype = ALL_NWRITE_R;
683 			break;
684 		case RDW_LAST_NWRITE_R:
685 		default:
686 			rtype = LAST_NWRITE_R;
687 			break;
688 		}
689 	} else {
690 		dev_err(dchan->device->dev,
691 			"%s: Unsupported DMA direction option\n", __func__);
692 		return NULL;
693 	}
694 
695 	for_each_sg(sgl, sg, sg_len, i) {
696 		int err;
697 
698 		dev_dbg(dchan->device->dev, "%s: sg #%d\n", __func__, i);
699 		desc = tsi721_desc_get(bdma_chan);
700 		if (!desc) {
701 			dev_err(dchan->device->dev,
702 				"Not enough descriptors available\n");
703 			goto err_desc_get;
704 		}
705 
706 		if (sg_is_last(sg))
707 			desc->interrupt = (flags & DMA_PREP_INTERRUPT) != 0;
708 		else
709 			desc->interrupt = false;
710 
711 		desc->destid = rext->destid;
712 		desc->rio_addr = rio_addr;
713 		desc->rio_addr_u = 0;
714 
715 		err = tsi721_fill_desc(bdma_chan, desc, sg, rtype, sys_size);
716 		if (err) {
717 			dev_err(dchan->device->dev,
718 				"Failed to build desc: %d\n", err);
719 			goto err_desc_get;
720 		}
721 
722 		rio_addr += sg_dma_len(sg);
723 
724 		if (!first)
725 			first = desc;
726 		else
727 			list_add_tail(&desc->desc_node, &first->tx_list);
728 	}
729 
730 	first->txd.cookie = -EBUSY;
731 	desc->txd.flags = flags;
732 
733 	return &first->txd;
734 
735 err_desc_get:
736 	tsi721_desc_put(bdma_chan, first);
737 	return NULL;
738 }
739 
740 static int tsi721_device_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd,
741 			     unsigned long arg)
742 {
743 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
744 	struct tsi721_tx_desc *desc, *_d;
745 	LIST_HEAD(list);
746 
747 	dev_dbg(dchan->device->dev, "%s: Entry\n", __func__);
748 
749 	if (cmd != DMA_TERMINATE_ALL)
750 		return -ENXIO;
751 
752 	spin_lock_bh(&bdma_chan->lock);
753 
754 	/* make sure to stop the transfer */
755 	iowrite32(TSI721_DMAC_CTL_SUSP, bdma_chan->regs + TSI721_DMAC_CTL);
756 
757 	list_splice_init(&bdma_chan->active_list, &list);
758 	list_splice_init(&bdma_chan->queue, &list);
759 
760 	list_for_each_entry_safe(desc, _d, &list, desc_node)
761 		tsi721_dma_chain_complete(bdma_chan, desc);
762 
763 	spin_unlock_bh(&bdma_chan->lock);
764 
765 	return 0;
766 }
767 
768 int tsi721_register_dma(struct tsi721_device *priv)
769 {
770 	int i;
771 	int nr_channels = TSI721_DMA_MAXCH;
772 	int err;
773 	struct rio_mport *mport = priv->mport;
774 
775 	mport->dma.dev = &priv->pdev->dev;
776 	mport->dma.chancnt = nr_channels;
777 
778 	INIT_LIST_HEAD(&mport->dma.channels);
779 
780 	for (i = 0; i < nr_channels; i++) {
781 		struct tsi721_bdma_chan *bdma_chan = &priv->bdma[i];
782 
783 		if (i == TSI721_DMACH_MAINT)
784 			continue;
785 
786 		bdma_chan->bd_num = 64;
787 		bdma_chan->regs = priv->regs + TSI721_DMAC_BASE(i);
788 
789 		bdma_chan->dchan.device = &mport->dma;
790 		bdma_chan->dchan.cookie = 1;
791 		bdma_chan->dchan.chan_id = i;
792 		bdma_chan->id = i;
793 
794 		spin_lock_init(&bdma_chan->lock);
795 
796 		INIT_LIST_HEAD(&bdma_chan->active_list);
797 		INIT_LIST_HEAD(&bdma_chan->queue);
798 		INIT_LIST_HEAD(&bdma_chan->free_list);
799 
800 		tasklet_init(&bdma_chan->tasklet, tsi721_dma_tasklet,
801 			     (unsigned long)bdma_chan);
802 		tasklet_disable(&bdma_chan->tasklet);
803 		list_add_tail(&bdma_chan->dchan.device_node,
804 			      &mport->dma.channels);
805 	}
806 
807 	dma_cap_zero(mport->dma.cap_mask);
808 	dma_cap_set(DMA_PRIVATE, mport->dma.cap_mask);
809 	dma_cap_set(DMA_SLAVE, mport->dma.cap_mask);
810 
811 	mport->dma.device_alloc_chan_resources = tsi721_alloc_chan_resources;
812 	mport->dma.device_free_chan_resources = tsi721_free_chan_resources;
813 	mport->dma.device_tx_status = tsi721_tx_status;
814 	mport->dma.device_issue_pending = tsi721_issue_pending;
815 	mport->dma.device_prep_slave_sg = tsi721_prep_rio_sg;
816 	mport->dma.device_control = tsi721_device_control;
817 
818 	err = dma_async_device_register(&mport->dma);
819 	if (err)
820 		dev_err(&priv->pdev->dev, "Failed to register DMA device\n");
821 
822 	return err;
823 }
824