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 	if (bdma_chan->active)
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_desc_fill_init(struct tsi721_tx_desc *desc, struct scatterlist *sg,
308 	enum dma_rtype rtype, u32 sys_size)
309 {
310 	struct tsi721_dma_desc *bd_ptr = desc->hw_desc;
311 	u64 rio_addr;
312 
313 	/* Initialize DMA descriptor */
314 	bd_ptr->type_id = cpu_to_le32((DTYPE1 << 29) |
315 					(rtype << 19) | desc->destid);
316 	bd_ptr->bcount = cpu_to_le32(((desc->rio_addr & 0x3) << 30) |
317 				     (sys_size << 26));
318 	rio_addr = (desc->rio_addr >> 2) |
319 				((u64)(desc->rio_addr_u & 0x3) << 62);
320 	bd_ptr->raddr_lo = cpu_to_le32(rio_addr & 0xffffffff);
321 	bd_ptr->raddr_hi = cpu_to_le32(rio_addr >> 32);
322 	bd_ptr->t1.bufptr_lo = cpu_to_le32(
323 					(u64)sg_dma_address(sg) & 0xffffffff);
324 	bd_ptr->t1.bufptr_hi = cpu_to_le32((u64)sg_dma_address(sg) >> 32);
325 	bd_ptr->t1.s_dist = 0;
326 	bd_ptr->t1.s_size = 0;
327 
328 	return 0;
329 }
330 
331 static int
332 tsi721_desc_fill_end(struct tsi721_tx_desc *desc)
333 {
334 	struct tsi721_dma_desc *bd_ptr = desc->hw_desc;
335 
336 	/* Update DMA descriptor */
337 	if (desc->interrupt)
338 		bd_ptr->type_id |= cpu_to_le32(TSI721_DMAD_IOF);
339 	bd_ptr->bcount |= cpu_to_le32(desc->bcount & TSI721_DMAD_BCOUNT1);
340 
341 	return 0;
342 }
343 
344 
345 static void tsi721_dma_chain_complete(struct tsi721_bdma_chan *bdma_chan,
346 				      struct tsi721_tx_desc *desc)
347 {
348 	struct dma_async_tx_descriptor *txd = &desc->txd;
349 	dma_async_tx_callback callback = txd->callback;
350 	void *param = txd->callback_param;
351 
352 	list_splice_init(&desc->tx_list, &bdma_chan->free_list);
353 	list_move(&desc->desc_node, &bdma_chan->free_list);
354 	bdma_chan->completed_cookie = txd->cookie;
355 
356 	if (callback)
357 		callback(param);
358 }
359 
360 static void tsi721_dma_complete_all(struct tsi721_bdma_chan *bdma_chan)
361 {
362 	struct tsi721_tx_desc *desc, *_d;
363 	LIST_HEAD(list);
364 
365 	BUG_ON(!tsi721_dma_is_idle(bdma_chan));
366 
367 	if (!list_empty(&bdma_chan->queue))
368 		tsi721_start_dma(bdma_chan);
369 
370 	list_splice_init(&bdma_chan->active_list, &list);
371 	list_splice_init(&bdma_chan->queue, &bdma_chan->active_list);
372 
373 	list_for_each_entry_safe(desc, _d, &list, desc_node)
374 		tsi721_dma_chain_complete(bdma_chan, desc);
375 }
376 
377 static void tsi721_clr_stat(struct tsi721_bdma_chan *bdma_chan)
378 {
379 	u32 srd_ptr;
380 	u64 *sts_ptr;
381 	int i, j;
382 
383 	/* Check and clear descriptor status FIFO entries */
384 	srd_ptr = bdma_chan->sts_rdptr;
385 	sts_ptr = bdma_chan->sts_base;
386 	j = srd_ptr * 8;
387 	while (sts_ptr[j]) {
388 		for (i = 0; i < 8 && sts_ptr[j]; i++, j++)
389 			sts_ptr[j] = 0;
390 
391 		++srd_ptr;
392 		srd_ptr %= bdma_chan->sts_size;
393 		j = srd_ptr * 8;
394 	}
395 
396 	iowrite32(srd_ptr, bdma_chan->regs + TSI721_DMAC_DSRP);
397 	bdma_chan->sts_rdptr = srd_ptr;
398 }
399 
400 static void tsi721_advance_work(struct tsi721_bdma_chan *bdma_chan)
401 {
402 	if (list_empty(&bdma_chan->active_list) ||
403 		list_is_singular(&bdma_chan->active_list)) {
404 		dev_dbg(bdma_chan->dchan.device->dev,
405 			"%s: Active_list empty\n", __func__);
406 		tsi721_dma_complete_all(bdma_chan);
407 	} else {
408 		dev_dbg(bdma_chan->dchan.device->dev,
409 			"%s: Active_list NOT empty\n", __func__);
410 		tsi721_dma_chain_complete(bdma_chan,
411 					tsi721_dma_first_active(bdma_chan));
412 		tsi721_start_dma(bdma_chan);
413 	}
414 }
415 
416 static void tsi721_dma_tasklet(unsigned long data)
417 {
418 	struct tsi721_bdma_chan *bdma_chan = (struct tsi721_bdma_chan *)data;
419 	u32 dmac_int, dmac_sts;
420 
421 	dmac_int = ioread32(bdma_chan->regs + TSI721_DMAC_INT);
422 	dev_dbg(bdma_chan->dchan.device->dev, "%s: DMAC%d_INT = 0x%x\n",
423 		__func__, bdma_chan->id, dmac_int);
424 	/* Clear channel interrupts */
425 	iowrite32(dmac_int, bdma_chan->regs + TSI721_DMAC_INT);
426 
427 	if (dmac_int & TSI721_DMAC_INT_ERR) {
428 		dmac_sts = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
429 		dev_err(bdma_chan->dchan.device->dev,
430 			"%s: DMA ERROR - DMAC%d_STS = 0x%x\n",
431 			__func__, bdma_chan->id, dmac_sts);
432 	}
433 
434 	if (dmac_int & TSI721_DMAC_INT_STFULL) {
435 		dev_err(bdma_chan->dchan.device->dev,
436 			"%s: DMAC%d descriptor status FIFO is full\n",
437 			__func__, bdma_chan->id);
438 	}
439 
440 	if (dmac_int & (TSI721_DMAC_INT_DONE | TSI721_DMAC_INT_IOFDONE)) {
441 		tsi721_clr_stat(bdma_chan);
442 		spin_lock(&bdma_chan->lock);
443 		tsi721_advance_work(bdma_chan);
444 		spin_unlock(&bdma_chan->lock);
445 	}
446 
447 	/* Re-Enable BDMA channel interrupts */
448 	iowrite32(TSI721_DMAC_INT_ALL, bdma_chan->regs + TSI721_DMAC_INTE);
449 }
450 
451 static dma_cookie_t tsi721_tx_submit(struct dma_async_tx_descriptor *txd)
452 {
453 	struct tsi721_tx_desc *desc = to_tsi721_desc(txd);
454 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(txd->chan);
455 	dma_cookie_t cookie;
456 
457 	spin_lock_bh(&bdma_chan->lock);
458 
459 	cookie = txd->chan->cookie;
460 	if (++cookie < 0)
461 		cookie = 1;
462 	txd->chan->cookie = cookie;
463 	txd->cookie = cookie;
464 
465 	if (list_empty(&bdma_chan->active_list)) {
466 		list_add_tail(&desc->desc_node, &bdma_chan->active_list);
467 		tsi721_start_dma(bdma_chan);
468 	} else {
469 		list_add_tail(&desc->desc_node, &bdma_chan->queue);
470 	}
471 
472 	spin_unlock_bh(&bdma_chan->lock);
473 	return cookie;
474 }
475 
476 static int tsi721_alloc_chan_resources(struct dma_chan *dchan)
477 {
478 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
479 #ifdef CONFIG_PCI_MSI
480 	struct tsi721_device *priv = to_tsi721(dchan->device);
481 #endif
482 	struct tsi721_tx_desc *desc = NULL;
483 	LIST_HEAD(tmp_list);
484 	int i;
485 	int rc;
486 
487 	if (bdma_chan->bd_base)
488 		return bdma_chan->bd_num - 1;
489 
490 	/* Initialize BDMA channel */
491 	if (tsi721_bdma_ch_init(bdma_chan)) {
492 		dev_err(dchan->device->dev, "Unable to initialize data DMA"
493 			" channel %d, aborting\n", bdma_chan->id);
494 		return -ENOMEM;
495 	}
496 
497 	/* Alocate matching number of logical descriptors */
498 	desc = kcalloc((bdma_chan->bd_num - 1), sizeof(struct tsi721_tx_desc),
499 			GFP_KERNEL);
500 	if (!desc) {
501 		dev_err(dchan->device->dev,
502 			"Failed to allocate logical descriptors\n");
503 		rc = -ENOMEM;
504 		goto err_out;
505 	}
506 
507 	bdma_chan->tx_desc = desc;
508 
509 	for (i = 0; i < bdma_chan->bd_num - 1; i++) {
510 		dma_async_tx_descriptor_init(&desc[i].txd, dchan);
511 		desc[i].txd.tx_submit = tsi721_tx_submit;
512 		desc[i].txd.flags = DMA_CTRL_ACK;
513 		INIT_LIST_HEAD(&desc[i].tx_list);
514 		list_add_tail(&desc[i].desc_node, &tmp_list);
515 	}
516 
517 	spin_lock_bh(&bdma_chan->lock);
518 	list_splice(&tmp_list, &bdma_chan->free_list);
519 	bdma_chan->completed_cookie = dchan->cookie = 1;
520 	spin_unlock_bh(&bdma_chan->lock);
521 
522 #ifdef CONFIG_PCI_MSI
523 	if (priv->flags & TSI721_USING_MSIX) {
524 		/* Request interrupt service if we are in MSI-X mode */
525 		rc = request_irq(
526 			priv->msix[TSI721_VECT_DMA0_DONE +
527 				   bdma_chan->id].vector,
528 			tsi721_bdma_msix, 0,
529 			priv->msix[TSI721_VECT_DMA0_DONE +
530 				   bdma_chan->id].irq_name,
531 			(void *)bdma_chan);
532 
533 		if (rc) {
534 			dev_dbg(dchan->device->dev,
535 				"Unable to allocate MSI-X interrupt for "
536 				"BDMA%d-DONE\n", bdma_chan->id);
537 			goto err_out;
538 		}
539 
540 		rc = request_irq(priv->msix[TSI721_VECT_DMA0_INT +
541 					    bdma_chan->id].vector,
542 				tsi721_bdma_msix, 0,
543 				priv->msix[TSI721_VECT_DMA0_INT +
544 					   bdma_chan->id].irq_name,
545 				(void *)bdma_chan);
546 
547 		if (rc)	{
548 			dev_dbg(dchan->device->dev,
549 				"Unable to allocate MSI-X interrupt for "
550 				"BDMA%d-INT\n", bdma_chan->id);
551 			free_irq(
552 				priv->msix[TSI721_VECT_DMA0_DONE +
553 					   bdma_chan->id].vector,
554 				(void *)bdma_chan);
555 			rc = -EIO;
556 			goto err_out;
557 		}
558 	}
559 #endif /* CONFIG_PCI_MSI */
560 
561 	bdma_chan->active = true;
562 	tsi721_bdma_interrupt_enable(bdma_chan, 1);
563 
564 	return bdma_chan->bd_num - 1;
565 
566 err_out:
567 	kfree(desc);
568 	tsi721_bdma_ch_free(bdma_chan);
569 	return rc;
570 }
571 
572 static void tsi721_free_chan_resources(struct dma_chan *dchan)
573 {
574 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
575 	struct tsi721_device *priv = to_tsi721(dchan->device);
576 	LIST_HEAD(list);
577 
578 	dev_dbg(dchan->device->dev, "%s: Entry\n", __func__);
579 
580 	if (bdma_chan->bd_base == NULL)
581 		return;
582 
583 	BUG_ON(!list_empty(&bdma_chan->active_list));
584 	BUG_ON(!list_empty(&bdma_chan->queue));
585 
586 	tsi721_bdma_interrupt_enable(bdma_chan, 0);
587 	bdma_chan->active = false;
588 
589 #ifdef CONFIG_PCI_MSI
590 	if (priv->flags & TSI721_USING_MSIX) {
591 		synchronize_irq(priv->msix[TSI721_VECT_DMA0_DONE +
592 					   bdma_chan->id].vector);
593 		synchronize_irq(priv->msix[TSI721_VECT_DMA0_INT +
594 					   bdma_chan->id].vector);
595 	} else
596 #endif
597 	synchronize_irq(priv->pdev->irq);
598 
599 	tasklet_kill(&bdma_chan->tasklet);
600 
601 	spin_lock_bh(&bdma_chan->lock);
602 	list_splice_init(&bdma_chan->free_list, &list);
603 	spin_unlock_bh(&bdma_chan->lock);
604 
605 #ifdef CONFIG_PCI_MSI
606 	if (priv->flags & TSI721_USING_MSIX) {
607 		free_irq(priv->msix[TSI721_VECT_DMA0_DONE +
608 				    bdma_chan->id].vector, (void *)bdma_chan);
609 		free_irq(priv->msix[TSI721_VECT_DMA0_INT +
610 				    bdma_chan->id].vector, (void *)bdma_chan);
611 	}
612 #endif /* CONFIG_PCI_MSI */
613 
614 	tsi721_bdma_ch_free(bdma_chan);
615 	kfree(bdma_chan->tx_desc);
616 }
617 
618 static
619 enum dma_status tsi721_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
620 				 struct dma_tx_state *txstate)
621 {
622 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
623 	dma_cookie_t		last_used;
624 	dma_cookie_t		last_completed;
625 	int			ret;
626 
627 	spin_lock_bh(&bdma_chan->lock);
628 	last_completed = bdma_chan->completed_cookie;
629 	last_used = dchan->cookie;
630 	spin_unlock_bh(&bdma_chan->lock);
631 
632 	ret = dma_async_is_complete(cookie, last_completed, last_used);
633 
634 	dma_set_tx_state(txstate, last_completed, last_used, 0);
635 
636 	dev_dbg(dchan->device->dev,
637 		"%s: exit, ret: %d, last_completed: %d, last_used: %d\n",
638 		__func__, ret, last_completed, last_used);
639 
640 	return ret;
641 }
642 
643 static void tsi721_issue_pending(struct dma_chan *dchan)
644 {
645 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
646 
647 	dev_dbg(dchan->device->dev, "%s: Entry\n", __func__);
648 
649 	if (tsi721_dma_is_idle(bdma_chan)) {
650 		spin_lock_bh(&bdma_chan->lock);
651 		tsi721_advance_work(bdma_chan);
652 		spin_unlock_bh(&bdma_chan->lock);
653 	} else
654 		dev_dbg(dchan->device->dev,
655 			"%s: DMA channel still busy\n", __func__);
656 }
657 
658 static
659 struct dma_async_tx_descriptor *tsi721_prep_rio_sg(struct dma_chan *dchan,
660 			struct scatterlist *sgl, unsigned int sg_len,
661 			enum dma_transfer_direction dir, unsigned long flags,
662 			void *tinfo)
663 {
664 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
665 	struct tsi721_tx_desc *desc = NULL;
666 	struct tsi721_tx_desc *first = NULL;
667 	struct scatterlist *sg;
668 	struct rio_dma_ext *rext = tinfo;
669 	u64 rio_addr = rext->rio_addr; /* limited to 64-bit rio_addr for now */
670 	unsigned int i;
671 	u32 sys_size = dma_to_mport(dchan->device)->sys_size;
672 	enum dma_rtype rtype;
673 	dma_addr_t next_addr = -1;
674 
675 	if (!sgl || !sg_len) {
676 		dev_err(dchan->device->dev, "%s: No SG list\n", __func__);
677 		return NULL;
678 	}
679 
680 	if (dir == DMA_DEV_TO_MEM)
681 		rtype = NREAD;
682 	else if (dir == DMA_MEM_TO_DEV) {
683 		switch (rext->wr_type) {
684 		case RDW_ALL_NWRITE:
685 			rtype = ALL_NWRITE;
686 			break;
687 		case RDW_ALL_NWRITE_R:
688 			rtype = ALL_NWRITE_R;
689 			break;
690 		case RDW_LAST_NWRITE_R:
691 		default:
692 			rtype = LAST_NWRITE_R;
693 			break;
694 		}
695 	} else {
696 		dev_err(dchan->device->dev,
697 			"%s: Unsupported DMA direction option\n", __func__);
698 		return NULL;
699 	}
700 
701 	for_each_sg(sgl, sg, sg_len, i) {
702 		int err;
703 
704 		if (sg_dma_len(sg) > TSI721_BDMA_MAX_BCOUNT) {
705 			dev_err(dchan->device->dev,
706 				"%s: SG entry %d is too large\n", __func__, i);
707 			goto err_desc_put;
708 		}
709 
710 		/*
711 		 * If this sg entry forms contiguous block with previous one,
712 		 * try to merge it into existing DMA descriptor
713 		 */
714 		if (desc) {
715 			if (next_addr == sg_dma_address(sg) &&
716 			    desc->bcount + sg_dma_len(sg) <=
717 						TSI721_BDMA_MAX_BCOUNT) {
718 				/* Adjust byte count of the descriptor */
719 				desc->bcount += sg_dma_len(sg);
720 				goto entry_done;
721 			}
722 
723 			/*
724 			 * Finalize this descriptor using total
725 			 * byte count value.
726 			 */
727 			tsi721_desc_fill_end(desc);
728 			dev_dbg(dchan->device->dev, "%s: desc final len: %d\n",
729 				__func__, desc->bcount);
730 		}
731 
732 		/*
733 		 * Obtain and initialize a new descriptor
734 		 */
735 		desc = tsi721_desc_get(bdma_chan);
736 		if (!desc) {
737 			dev_err(dchan->device->dev,
738 				"%s: Failed to get new descriptor for SG %d\n",
739 				__func__, i);
740 			goto err_desc_put;
741 		}
742 
743 		desc->destid = rext->destid;
744 		desc->rio_addr = rio_addr;
745 		desc->rio_addr_u = 0;
746 		desc->bcount = sg_dma_len(sg);
747 
748 		dev_dbg(dchan->device->dev,
749 			"sg%d desc: 0x%llx, addr: 0x%llx len: %d\n",
750 			i, (u64)desc->txd.phys,
751 			(unsigned long long)sg_dma_address(sg),
752 			sg_dma_len(sg));
753 
754 		dev_dbg(dchan->device->dev,
755 			"bd_ptr = %p did=%d raddr=0x%llx\n",
756 			desc->hw_desc, desc->destid, desc->rio_addr);
757 
758 		err = tsi721_desc_fill_init(desc, sg, rtype, sys_size);
759 		if (err) {
760 			dev_err(dchan->device->dev,
761 				"Failed to build desc: %d\n", err);
762 			goto err_desc_put;
763 		}
764 
765 		next_addr = sg_dma_address(sg);
766 
767 		if (!first)
768 			first = desc;
769 		else
770 			list_add_tail(&desc->desc_node, &first->tx_list);
771 
772 entry_done:
773 		if (sg_is_last(sg)) {
774 			desc->interrupt = (flags & DMA_PREP_INTERRUPT) != 0;
775 			tsi721_desc_fill_end(desc);
776 			dev_dbg(dchan->device->dev, "%s: desc final len: %d\n",
777 				__func__, desc->bcount);
778 		} else {
779 			rio_addr += sg_dma_len(sg);
780 			next_addr += sg_dma_len(sg);
781 		}
782 	}
783 
784 	first->txd.cookie = -EBUSY;
785 	desc->txd.flags = flags;
786 
787 	return &first->txd;
788 
789 err_desc_put:
790 	tsi721_desc_put(bdma_chan, first);
791 	return NULL;
792 }
793 
794 static int tsi721_device_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd,
795 			     unsigned long arg)
796 {
797 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
798 	struct tsi721_tx_desc *desc, *_d;
799 	LIST_HEAD(list);
800 
801 	dev_dbg(dchan->device->dev, "%s: Entry\n", __func__);
802 
803 	if (cmd != DMA_TERMINATE_ALL)
804 		return -ENXIO;
805 
806 	spin_lock_bh(&bdma_chan->lock);
807 
808 	/* make sure to stop the transfer */
809 	iowrite32(TSI721_DMAC_CTL_SUSP, bdma_chan->regs + TSI721_DMAC_CTL);
810 
811 	list_splice_init(&bdma_chan->active_list, &list);
812 	list_splice_init(&bdma_chan->queue, &list);
813 
814 	list_for_each_entry_safe(desc, _d, &list, desc_node)
815 		tsi721_dma_chain_complete(bdma_chan, desc);
816 
817 	spin_unlock_bh(&bdma_chan->lock);
818 
819 	return 0;
820 }
821 
822 int tsi721_register_dma(struct tsi721_device *priv)
823 {
824 	int i;
825 	int nr_channels = TSI721_DMA_MAXCH;
826 	int err;
827 	struct rio_mport *mport = priv->mport;
828 
829 	mport->dma.dev = &priv->pdev->dev;
830 	mport->dma.chancnt = nr_channels;
831 
832 	INIT_LIST_HEAD(&mport->dma.channels);
833 
834 	for (i = 0; i < nr_channels; i++) {
835 		struct tsi721_bdma_chan *bdma_chan = &priv->bdma[i];
836 
837 		if (i == TSI721_DMACH_MAINT)
838 			continue;
839 
840 		bdma_chan->bd_num = TSI721_BDMA_BD_RING_SZ;
841 		bdma_chan->regs = priv->regs + TSI721_DMAC_BASE(i);
842 
843 		bdma_chan->dchan.device = &mport->dma;
844 		bdma_chan->dchan.cookie = 1;
845 		bdma_chan->dchan.chan_id = i;
846 		bdma_chan->id = i;
847 		bdma_chan->active = false;
848 
849 		spin_lock_init(&bdma_chan->lock);
850 
851 		INIT_LIST_HEAD(&bdma_chan->active_list);
852 		INIT_LIST_HEAD(&bdma_chan->queue);
853 		INIT_LIST_HEAD(&bdma_chan->free_list);
854 
855 		tasklet_init(&bdma_chan->tasklet, tsi721_dma_tasklet,
856 			     (unsigned long)bdma_chan);
857 		list_add_tail(&bdma_chan->dchan.device_node,
858 			      &mport->dma.channels);
859 	}
860 
861 	dma_cap_zero(mport->dma.cap_mask);
862 	dma_cap_set(DMA_PRIVATE, mport->dma.cap_mask);
863 	dma_cap_set(DMA_SLAVE, mport->dma.cap_mask);
864 
865 	mport->dma.device_alloc_chan_resources = tsi721_alloc_chan_resources;
866 	mport->dma.device_free_chan_resources = tsi721_free_chan_resources;
867 	mport->dma.device_tx_status = tsi721_tx_status;
868 	mport->dma.device_issue_pending = tsi721_issue_pending;
869 	mport->dma.device_prep_slave_sg = tsi721_prep_rio_sg;
870 	mport->dma.device_control = tsi721_device_control;
871 
872 	err = dma_async_device_register(&mport->dma);
873 	if (err)
874 		dev_err(&priv->pdev->dev, "Failed to register DMA device\n");
875 
876 	return err;
877 }
878