1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * DMA Engine support for Tsi721 PCIExpress-to-SRIO bridge
4  *
5  * Copyright (c) 2011-2014 Integrated Device Technology, Inc.
6  * Alexandre Bounine <alexandre.bounine@idt.com>
7  */
8 
9 #include <linux/io.h>
10 #include <linux/errno.h>
11 #include <linux/init.h>
12 #include <linux/ioport.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/pci.h>
16 #include <linux/rio.h>
17 #include <linux/rio_drv.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/interrupt.h>
20 #include <linux/kfifo.h>
21 #include <linux/sched.h>
22 #include <linux/delay.h>
23 #include "../../dma/dmaengine.h"
24 
25 #include "tsi721.h"
26 
27 #ifdef CONFIG_PCI_MSI
28 static irqreturn_t tsi721_bdma_msix(int irq, void *ptr);
29 #endif
30 static int tsi721_submit_sg(struct tsi721_tx_desc *desc);
31 
32 static unsigned int dma_desc_per_channel = 128;
33 module_param(dma_desc_per_channel, uint, S_IRUGO);
34 MODULE_PARM_DESC(dma_desc_per_channel,
35 		 "Number of DMA descriptors per channel (default: 128)");
36 
37 static unsigned int dma_txqueue_sz = 16;
38 module_param(dma_txqueue_sz, uint, S_IRUGO);
39 MODULE_PARM_DESC(dma_txqueue_sz,
40 		 "DMA Transactions Queue Size (default: 16)");
41 
42 static u8 dma_sel = 0x7f;
43 module_param(dma_sel, byte, S_IRUGO);
44 MODULE_PARM_DESC(dma_sel,
45 		 "DMA Channel Selection Mask (default: 0x7f = all)");
46 
47 static inline struct tsi721_bdma_chan *to_tsi721_chan(struct dma_chan *chan)
48 {
49 	return container_of(chan, struct tsi721_bdma_chan, dchan);
50 }
51 
52 static inline struct tsi721_device *to_tsi721(struct dma_device *ddev)
53 {
54 	return container_of(ddev, struct rio_mport, dma)->priv;
55 }
56 
57 static inline
58 struct tsi721_tx_desc *to_tsi721_desc(struct dma_async_tx_descriptor *txd)
59 {
60 	return container_of(txd, struct tsi721_tx_desc, txd);
61 }
62 
63 static int tsi721_bdma_ch_init(struct tsi721_bdma_chan *bdma_chan, int bd_num)
64 {
65 	struct tsi721_dma_desc *bd_ptr;
66 	struct device *dev = bdma_chan->dchan.device->dev;
67 	u64		*sts_ptr;
68 	dma_addr_t	bd_phys;
69 	dma_addr_t	sts_phys;
70 	int		sts_size;
71 #ifdef CONFIG_PCI_MSI
72 	struct tsi721_device *priv = to_tsi721(bdma_chan->dchan.device);
73 #endif
74 
75 	tsi_debug(DMA, &bdma_chan->dchan.dev->device, "DMAC%d", bdma_chan->id);
76 
77 	/*
78 	 * Allocate space for DMA descriptors
79 	 * (add an extra element for link descriptor)
80 	 */
81 	bd_ptr = dma_alloc_coherent(dev,
82 				    (bd_num + 1) * sizeof(struct tsi721_dma_desc),
83 				    &bd_phys, GFP_ATOMIC);
84 	if (!bd_ptr)
85 		return -ENOMEM;
86 
87 	bdma_chan->bd_num = bd_num;
88 	bdma_chan->bd_phys = bd_phys;
89 	bdma_chan->bd_base = bd_ptr;
90 
91 	tsi_debug(DMA, &bdma_chan->dchan.dev->device,
92 		  "DMAC%d descriptors @ %p (phys = %pad)",
93 		  bdma_chan->id, bd_ptr, &bd_phys);
94 
95 	/* Allocate space for descriptor status FIFO */
96 	sts_size = ((bd_num + 1) >= TSI721_DMA_MINSTSSZ) ?
97 					(bd_num + 1) : TSI721_DMA_MINSTSSZ;
98 	sts_size = roundup_pow_of_two(sts_size);
99 	sts_ptr = dma_alloc_coherent(dev,
100 				     sts_size * sizeof(struct tsi721_dma_sts),
101 				     &sts_phys, GFP_ATOMIC);
102 	if (!sts_ptr) {
103 		/* Free space allocated for DMA descriptors */
104 		dma_free_coherent(dev,
105 				  (bd_num + 1) * sizeof(struct tsi721_dma_desc),
106 				  bd_ptr, bd_phys);
107 		bdma_chan->bd_base = NULL;
108 		return -ENOMEM;
109 	}
110 
111 	bdma_chan->sts_phys = sts_phys;
112 	bdma_chan->sts_base = sts_ptr;
113 	bdma_chan->sts_size = sts_size;
114 
115 	tsi_debug(DMA, &bdma_chan->dchan.dev->device,
116 		"DMAC%d desc status FIFO @ %p (phys = %pad) size=0x%x",
117 		bdma_chan->id, sts_ptr, &sts_phys, sts_size);
118 
119 	/* Initialize DMA descriptors ring using added link descriptor */
120 	bd_ptr[bd_num].type_id = cpu_to_le32(DTYPE3 << 29);
121 	bd_ptr[bd_num].next_lo = cpu_to_le32((u64)bd_phys &
122 						 TSI721_DMAC_DPTRL_MASK);
123 	bd_ptr[bd_num].next_hi = cpu_to_le32((u64)bd_phys >> 32);
124 
125 	/* Setup DMA descriptor pointers */
126 	iowrite32(((u64)bd_phys >> 32),
127 		bdma_chan->regs + TSI721_DMAC_DPTRH);
128 	iowrite32(((u64)bd_phys & TSI721_DMAC_DPTRL_MASK),
129 		bdma_chan->regs + TSI721_DMAC_DPTRL);
130 
131 	/* Setup descriptor status FIFO */
132 	iowrite32(((u64)sts_phys >> 32),
133 		bdma_chan->regs + TSI721_DMAC_DSBH);
134 	iowrite32(((u64)sts_phys & TSI721_DMAC_DSBL_MASK),
135 		bdma_chan->regs + TSI721_DMAC_DSBL);
136 	iowrite32(TSI721_DMAC_DSSZ_SIZE(sts_size),
137 		bdma_chan->regs + TSI721_DMAC_DSSZ);
138 
139 	/* Clear interrupt bits */
140 	iowrite32(TSI721_DMAC_INT_ALL,
141 		bdma_chan->regs + TSI721_DMAC_INT);
142 
143 	ioread32(bdma_chan->regs + TSI721_DMAC_INT);
144 
145 #ifdef CONFIG_PCI_MSI
146 	/* Request interrupt service if we are in MSI-X mode */
147 	if (priv->flags & TSI721_USING_MSIX) {
148 		int rc, idx;
149 
150 		idx = TSI721_VECT_DMA0_DONE + bdma_chan->id;
151 
152 		rc = request_irq(priv->msix[idx].vector, tsi721_bdma_msix, 0,
153 				 priv->msix[idx].irq_name, (void *)bdma_chan);
154 
155 		if (rc) {
156 			tsi_debug(DMA, &bdma_chan->dchan.dev->device,
157 				  "Unable to get MSI-X for DMAC%d-DONE",
158 				  bdma_chan->id);
159 			goto err_out;
160 		}
161 
162 		idx = TSI721_VECT_DMA0_INT + bdma_chan->id;
163 
164 		rc = request_irq(priv->msix[idx].vector, tsi721_bdma_msix, 0,
165 				priv->msix[idx].irq_name, (void *)bdma_chan);
166 
167 		if (rc)	{
168 			tsi_debug(DMA, &bdma_chan->dchan.dev->device,
169 				  "Unable to get MSI-X for DMAC%d-INT",
170 				  bdma_chan->id);
171 			free_irq(
172 				priv->msix[TSI721_VECT_DMA0_DONE +
173 					    bdma_chan->id].vector,
174 				(void *)bdma_chan);
175 		}
176 
177 err_out:
178 		if (rc) {
179 			/* Free space allocated for DMA descriptors */
180 			dma_free_coherent(dev,
181 				(bd_num + 1) * sizeof(struct tsi721_dma_desc),
182 				bd_ptr, bd_phys);
183 			bdma_chan->bd_base = NULL;
184 
185 			/* Free space allocated for status descriptors */
186 			dma_free_coherent(dev,
187 				sts_size * sizeof(struct tsi721_dma_sts),
188 				sts_ptr, sts_phys);
189 			bdma_chan->sts_base = NULL;
190 
191 			return -EIO;
192 		}
193 	}
194 #endif /* CONFIG_PCI_MSI */
195 
196 	/* Toggle DMA channel initialization */
197 	iowrite32(TSI721_DMAC_CTL_INIT,	bdma_chan->regs + TSI721_DMAC_CTL);
198 	ioread32(bdma_chan->regs + TSI721_DMAC_CTL);
199 	bdma_chan->wr_count = bdma_chan->wr_count_next = 0;
200 	bdma_chan->sts_rdptr = 0;
201 	udelay(10);
202 
203 	return 0;
204 }
205 
206 static int tsi721_bdma_ch_free(struct tsi721_bdma_chan *bdma_chan)
207 {
208 	u32 ch_stat;
209 #ifdef CONFIG_PCI_MSI
210 	struct tsi721_device *priv = to_tsi721(bdma_chan->dchan.device);
211 #endif
212 
213 	if (!bdma_chan->bd_base)
214 		return 0;
215 
216 	/* Check if DMA channel still running */
217 	ch_stat = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
218 	if (ch_stat & TSI721_DMAC_STS_RUN)
219 		return -EFAULT;
220 
221 	/* Put DMA channel into init state */
222 	iowrite32(TSI721_DMAC_CTL_INIT,	bdma_chan->regs + TSI721_DMAC_CTL);
223 
224 #ifdef CONFIG_PCI_MSI
225 	if (priv->flags & TSI721_USING_MSIX) {
226 		free_irq(priv->msix[TSI721_VECT_DMA0_DONE +
227 				    bdma_chan->id].vector, (void *)bdma_chan);
228 		free_irq(priv->msix[TSI721_VECT_DMA0_INT +
229 				    bdma_chan->id].vector, (void *)bdma_chan);
230 	}
231 #endif /* CONFIG_PCI_MSI */
232 
233 	/* Free space allocated for DMA descriptors */
234 	dma_free_coherent(bdma_chan->dchan.device->dev,
235 		(bdma_chan->bd_num + 1) * sizeof(struct tsi721_dma_desc),
236 		bdma_chan->bd_base, bdma_chan->bd_phys);
237 	bdma_chan->bd_base = NULL;
238 
239 	/* Free space allocated for status FIFO */
240 	dma_free_coherent(bdma_chan->dchan.device->dev,
241 		bdma_chan->sts_size * sizeof(struct tsi721_dma_sts),
242 		bdma_chan->sts_base, bdma_chan->sts_phys);
243 	bdma_chan->sts_base = NULL;
244 	return 0;
245 }
246 
247 static void
248 tsi721_bdma_interrupt_enable(struct tsi721_bdma_chan *bdma_chan, int enable)
249 {
250 	if (enable) {
251 		/* Clear pending BDMA channel interrupts */
252 		iowrite32(TSI721_DMAC_INT_ALL,
253 			bdma_chan->regs + TSI721_DMAC_INT);
254 		ioread32(bdma_chan->regs + TSI721_DMAC_INT);
255 		/* Enable BDMA channel interrupts */
256 		iowrite32(TSI721_DMAC_INT_ALL,
257 			bdma_chan->regs + TSI721_DMAC_INTE);
258 	} else {
259 		/* Disable BDMA channel interrupts */
260 		iowrite32(0, bdma_chan->regs + TSI721_DMAC_INTE);
261 		/* Clear pending BDMA channel interrupts */
262 		iowrite32(TSI721_DMAC_INT_ALL,
263 			bdma_chan->regs + TSI721_DMAC_INT);
264 	}
265 
266 }
267 
268 static bool tsi721_dma_is_idle(struct tsi721_bdma_chan *bdma_chan)
269 {
270 	u32 sts;
271 
272 	sts = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
273 	return ((sts & TSI721_DMAC_STS_RUN) == 0);
274 }
275 
276 void tsi721_bdma_handler(struct tsi721_bdma_chan *bdma_chan)
277 {
278 	/* Disable BDMA channel interrupts */
279 	iowrite32(0, bdma_chan->regs + TSI721_DMAC_INTE);
280 	if (bdma_chan->active)
281 		tasklet_hi_schedule(&bdma_chan->tasklet);
282 }
283 
284 #ifdef CONFIG_PCI_MSI
285 /**
286  * tsi721_omsg_msix - MSI-X interrupt handler for BDMA channels
287  * @irq: Linux interrupt number
288  * @ptr: Pointer to interrupt-specific data (BDMA channel structure)
289  *
290  * Handles BDMA channel interrupts signaled using MSI-X.
291  */
292 static irqreturn_t tsi721_bdma_msix(int irq, void *ptr)
293 {
294 	struct tsi721_bdma_chan *bdma_chan = ptr;
295 
296 	if (bdma_chan->active)
297 		tasklet_hi_schedule(&bdma_chan->tasklet);
298 	return IRQ_HANDLED;
299 }
300 #endif /* CONFIG_PCI_MSI */
301 
302 /* Must be called with the spinlock held */
303 static void tsi721_start_dma(struct tsi721_bdma_chan *bdma_chan)
304 {
305 	if (!tsi721_dma_is_idle(bdma_chan)) {
306 		tsi_err(&bdma_chan->dchan.dev->device,
307 			"DMAC%d Attempt to start non-idle channel",
308 			bdma_chan->id);
309 		return;
310 	}
311 
312 	if (bdma_chan->wr_count == bdma_chan->wr_count_next) {
313 		tsi_err(&bdma_chan->dchan.dev->device,
314 			"DMAC%d Attempt to start DMA with no BDs ready %d",
315 			bdma_chan->id, task_pid_nr(current));
316 		return;
317 	}
318 
319 	tsi_debug(DMA, &bdma_chan->dchan.dev->device, "DMAC%d (wrc=%d) %d",
320 		  bdma_chan->id, bdma_chan->wr_count_next,
321 		  task_pid_nr(current));
322 
323 	iowrite32(bdma_chan->wr_count_next,
324 		bdma_chan->regs + TSI721_DMAC_DWRCNT);
325 	ioread32(bdma_chan->regs + TSI721_DMAC_DWRCNT);
326 
327 	bdma_chan->wr_count = bdma_chan->wr_count_next;
328 }
329 
330 static int
331 tsi721_desc_fill_init(struct tsi721_tx_desc *desc,
332 		      struct tsi721_dma_desc *bd_ptr,
333 		      struct scatterlist *sg, u32 sys_size)
334 {
335 	u64 rio_addr;
336 
337 	if (!bd_ptr)
338 		return -EINVAL;
339 
340 	/* Initialize DMA descriptor */
341 	bd_ptr->type_id = cpu_to_le32((DTYPE1 << 29) |
342 				      (desc->rtype << 19) | desc->destid);
343 	bd_ptr->bcount = cpu_to_le32(((desc->rio_addr & 0x3) << 30) |
344 				     (sys_size << 26));
345 	rio_addr = (desc->rio_addr >> 2) |
346 				((u64)(desc->rio_addr_u & 0x3) << 62);
347 	bd_ptr->raddr_lo = cpu_to_le32(rio_addr & 0xffffffff);
348 	bd_ptr->raddr_hi = cpu_to_le32(rio_addr >> 32);
349 	bd_ptr->t1.bufptr_lo = cpu_to_le32(
350 					(u64)sg_dma_address(sg) & 0xffffffff);
351 	bd_ptr->t1.bufptr_hi = cpu_to_le32((u64)sg_dma_address(sg) >> 32);
352 	bd_ptr->t1.s_dist = 0;
353 	bd_ptr->t1.s_size = 0;
354 
355 	return 0;
356 }
357 
358 static int
359 tsi721_desc_fill_end(struct tsi721_dma_desc *bd_ptr, u32 bcount, bool interrupt)
360 {
361 	if (!bd_ptr)
362 		return -EINVAL;
363 
364 	/* Update DMA descriptor */
365 	if (interrupt)
366 		bd_ptr->type_id |= cpu_to_le32(TSI721_DMAD_IOF);
367 	bd_ptr->bcount |= cpu_to_le32(bcount & TSI721_DMAD_BCOUNT1);
368 
369 	return 0;
370 }
371 
372 static void tsi721_dma_tx_err(struct tsi721_bdma_chan *bdma_chan,
373 			      struct tsi721_tx_desc *desc)
374 {
375 	struct dma_async_tx_descriptor *txd = &desc->txd;
376 	dma_async_tx_callback callback = txd->callback;
377 	void *param = txd->callback_param;
378 
379 	list_move(&desc->desc_node, &bdma_chan->free_list);
380 
381 	if (callback)
382 		callback(param);
383 }
384 
385 static void tsi721_clr_stat(struct tsi721_bdma_chan *bdma_chan)
386 {
387 	u32 srd_ptr;
388 	u64 *sts_ptr;
389 	int i, j;
390 
391 	/* Check and clear descriptor status FIFO entries */
392 	srd_ptr = bdma_chan->sts_rdptr;
393 	sts_ptr = bdma_chan->sts_base;
394 	j = srd_ptr * 8;
395 	while (sts_ptr[j]) {
396 		for (i = 0; i < 8 && sts_ptr[j]; i++, j++)
397 			sts_ptr[j] = 0;
398 
399 		++srd_ptr;
400 		srd_ptr %= bdma_chan->sts_size;
401 		j = srd_ptr * 8;
402 	}
403 
404 	iowrite32(srd_ptr, bdma_chan->regs + TSI721_DMAC_DSRP);
405 	bdma_chan->sts_rdptr = srd_ptr;
406 }
407 
408 /* Must be called with the channel spinlock held */
409 static int tsi721_submit_sg(struct tsi721_tx_desc *desc)
410 {
411 	struct dma_chan *dchan = desc->txd.chan;
412 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
413 	u32 sys_size;
414 	u64 rio_addr;
415 	dma_addr_t next_addr;
416 	u32 bcount;
417 	struct scatterlist *sg;
418 	unsigned int i;
419 	int err = 0;
420 	struct tsi721_dma_desc *bd_ptr = NULL;
421 	u32 idx, rd_idx;
422 	u32 add_count = 0;
423 	struct device *ch_dev = &dchan->dev->device;
424 
425 	if (!tsi721_dma_is_idle(bdma_chan)) {
426 		tsi_err(ch_dev, "DMAC%d ERR: Attempt to use non-idle channel",
427 			bdma_chan->id);
428 		return -EIO;
429 	}
430 
431 	/*
432 	 * Fill DMA channel's hardware buffer descriptors.
433 	 * (NOTE: RapidIO destination address is limited to 64 bits for now)
434 	 */
435 	rio_addr = desc->rio_addr;
436 	next_addr = -1;
437 	bcount = 0;
438 	sys_size = dma_to_mport(dchan->device)->sys_size;
439 
440 	rd_idx = ioread32(bdma_chan->regs + TSI721_DMAC_DRDCNT);
441 	rd_idx %= (bdma_chan->bd_num + 1);
442 
443 	idx = bdma_chan->wr_count_next % (bdma_chan->bd_num + 1);
444 	if (idx == bdma_chan->bd_num) {
445 		/* wrap around link descriptor */
446 		idx = 0;
447 		add_count++;
448 	}
449 
450 	tsi_debug(DMA, ch_dev, "DMAC%d BD ring status: rdi=%d wri=%d",
451 		  bdma_chan->id, rd_idx, idx);
452 
453 	for_each_sg(desc->sg, sg, desc->sg_len, i) {
454 
455 		tsi_debug(DMAV, ch_dev, "DMAC%d sg%d/%d addr: 0x%llx len: %d",
456 			bdma_chan->id, i, desc->sg_len,
457 			(unsigned long long)sg_dma_address(sg), sg_dma_len(sg));
458 
459 		if (sg_dma_len(sg) > TSI721_BDMA_MAX_BCOUNT) {
460 			tsi_err(ch_dev, "DMAC%d SG entry %d is too large",
461 				bdma_chan->id, i);
462 			err = -EINVAL;
463 			break;
464 		}
465 
466 		/*
467 		 * If this sg entry forms contiguous block with previous one,
468 		 * try to merge it into existing DMA descriptor
469 		 */
470 		if (next_addr == sg_dma_address(sg) &&
471 		    bcount + sg_dma_len(sg) <= TSI721_BDMA_MAX_BCOUNT) {
472 			/* Adjust byte count of the descriptor */
473 			bcount += sg_dma_len(sg);
474 			goto entry_done;
475 		} else if (next_addr != -1) {
476 			/* Finalize descriptor using total byte count value */
477 			tsi721_desc_fill_end(bd_ptr, bcount, 0);
478 			tsi_debug(DMAV, ch_dev,	"DMAC%d prev desc final len: %d",
479 				  bdma_chan->id, bcount);
480 		}
481 
482 		desc->rio_addr = rio_addr;
483 
484 		if (i && idx == rd_idx) {
485 			tsi_debug(DMAV, ch_dev,
486 				  "DMAC%d HW descriptor ring is full @ %d",
487 				  bdma_chan->id, i);
488 			desc->sg = sg;
489 			desc->sg_len -= i;
490 			break;
491 		}
492 
493 		bd_ptr = &((struct tsi721_dma_desc *)bdma_chan->bd_base)[idx];
494 		err = tsi721_desc_fill_init(desc, bd_ptr, sg, sys_size);
495 		if (err) {
496 			tsi_err(ch_dev, "Failed to build desc: err=%d", err);
497 			break;
498 		}
499 
500 		tsi_debug(DMAV, ch_dev, "DMAC%d bd_ptr = %p did=%d raddr=0x%llx",
501 			  bdma_chan->id, bd_ptr, desc->destid, desc->rio_addr);
502 
503 		next_addr = sg_dma_address(sg);
504 		bcount = sg_dma_len(sg);
505 
506 		add_count++;
507 		if (++idx == bdma_chan->bd_num) {
508 			/* wrap around link descriptor */
509 			idx = 0;
510 			add_count++;
511 		}
512 
513 entry_done:
514 		if (sg_is_last(sg)) {
515 			tsi721_desc_fill_end(bd_ptr, bcount, 0);
516 			tsi_debug(DMAV, ch_dev,
517 				  "DMAC%d last desc final len: %d",
518 				  bdma_chan->id, bcount);
519 			desc->sg_len = 0;
520 		} else {
521 			rio_addr += sg_dma_len(sg);
522 			next_addr += sg_dma_len(sg);
523 		}
524 	}
525 
526 	if (!err)
527 		bdma_chan->wr_count_next += add_count;
528 
529 	return err;
530 }
531 
532 static void tsi721_advance_work(struct tsi721_bdma_chan *bdma_chan,
533 				struct tsi721_tx_desc *desc)
534 {
535 	int err;
536 
537 	tsi_debug(DMA, &bdma_chan->dchan.dev->device, "DMAC%d", bdma_chan->id);
538 
539 	if (!tsi721_dma_is_idle(bdma_chan))
540 		return;
541 
542 	/*
543 	 * If there is no data transfer in progress, fetch new descriptor from
544 	 * the pending queue.
545 	*/
546 	if (!desc && !bdma_chan->active_tx && !list_empty(&bdma_chan->queue)) {
547 		desc = list_first_entry(&bdma_chan->queue,
548 					struct tsi721_tx_desc, desc_node);
549 		list_del_init((&desc->desc_node));
550 		bdma_chan->active_tx = desc;
551 	}
552 
553 	if (desc) {
554 		err = tsi721_submit_sg(desc);
555 		if (!err)
556 			tsi721_start_dma(bdma_chan);
557 		else {
558 			tsi721_dma_tx_err(bdma_chan, desc);
559 			tsi_debug(DMA, &bdma_chan->dchan.dev->device,
560 				"DMAC%d ERR: tsi721_submit_sg failed with err=%d",
561 				bdma_chan->id, err);
562 		}
563 	}
564 
565 	tsi_debug(DMA, &bdma_chan->dchan.dev->device, "DMAC%d Exit",
566 		  bdma_chan->id);
567 }
568 
569 static void tsi721_dma_tasklet(unsigned long data)
570 {
571 	struct tsi721_bdma_chan *bdma_chan = (struct tsi721_bdma_chan *)data;
572 	u32 dmac_int, dmac_sts;
573 
574 	dmac_int = ioread32(bdma_chan->regs + TSI721_DMAC_INT);
575 	tsi_debug(DMA, &bdma_chan->dchan.dev->device, "DMAC%d_INT = 0x%x",
576 		  bdma_chan->id, dmac_int);
577 	/* Clear channel interrupts */
578 	iowrite32(dmac_int, bdma_chan->regs + TSI721_DMAC_INT);
579 
580 	if (dmac_int & TSI721_DMAC_INT_ERR) {
581 		int i = 10000;
582 		struct tsi721_tx_desc *desc;
583 
584 		desc = bdma_chan->active_tx;
585 		dmac_sts = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
586 		tsi_err(&bdma_chan->dchan.dev->device,
587 			"DMAC%d_STS = 0x%x did=%d raddr=0x%llx",
588 			bdma_chan->id, dmac_sts, desc->destid, desc->rio_addr);
589 
590 		/* Re-initialize DMA channel if possible */
591 
592 		if ((dmac_sts & TSI721_DMAC_STS_ABORT) == 0)
593 			goto err_out;
594 
595 		tsi721_clr_stat(bdma_chan);
596 
597 		spin_lock(&bdma_chan->lock);
598 
599 		/* Put DMA channel into init state */
600 		iowrite32(TSI721_DMAC_CTL_INIT,
601 			  bdma_chan->regs + TSI721_DMAC_CTL);
602 		do {
603 			udelay(1);
604 			dmac_sts = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
605 			i--;
606 		} while ((dmac_sts & TSI721_DMAC_STS_ABORT) && i);
607 
608 		if (dmac_sts & TSI721_DMAC_STS_ABORT) {
609 			tsi_err(&bdma_chan->dchan.dev->device,
610 				"Failed to re-initiate DMAC%d",	bdma_chan->id);
611 			spin_unlock(&bdma_chan->lock);
612 			goto err_out;
613 		}
614 
615 		/* Setup DMA descriptor pointers */
616 		iowrite32(((u64)bdma_chan->bd_phys >> 32),
617 			bdma_chan->regs + TSI721_DMAC_DPTRH);
618 		iowrite32(((u64)bdma_chan->bd_phys & TSI721_DMAC_DPTRL_MASK),
619 			bdma_chan->regs + TSI721_DMAC_DPTRL);
620 
621 		/* Setup descriptor status FIFO */
622 		iowrite32(((u64)bdma_chan->sts_phys >> 32),
623 			bdma_chan->regs + TSI721_DMAC_DSBH);
624 		iowrite32(((u64)bdma_chan->sts_phys & TSI721_DMAC_DSBL_MASK),
625 			bdma_chan->regs + TSI721_DMAC_DSBL);
626 		iowrite32(TSI721_DMAC_DSSZ_SIZE(bdma_chan->sts_size),
627 			bdma_chan->regs + TSI721_DMAC_DSSZ);
628 
629 		/* Clear interrupt bits */
630 		iowrite32(TSI721_DMAC_INT_ALL,
631 			bdma_chan->regs + TSI721_DMAC_INT);
632 
633 		ioread32(bdma_chan->regs + TSI721_DMAC_INT);
634 
635 		bdma_chan->wr_count = bdma_chan->wr_count_next = 0;
636 		bdma_chan->sts_rdptr = 0;
637 		udelay(10);
638 
639 		desc = bdma_chan->active_tx;
640 		desc->status = DMA_ERROR;
641 		dma_cookie_complete(&desc->txd);
642 		list_add(&desc->desc_node, &bdma_chan->free_list);
643 		bdma_chan->active_tx = NULL;
644 		if (bdma_chan->active)
645 			tsi721_advance_work(bdma_chan, NULL);
646 		spin_unlock(&bdma_chan->lock);
647 	}
648 
649 	if (dmac_int & TSI721_DMAC_INT_STFULL) {
650 		tsi_err(&bdma_chan->dchan.dev->device,
651 			"DMAC%d descriptor status FIFO is full",
652 			bdma_chan->id);
653 	}
654 
655 	if (dmac_int & (TSI721_DMAC_INT_DONE | TSI721_DMAC_INT_IOFDONE)) {
656 		struct tsi721_tx_desc *desc;
657 
658 		tsi721_clr_stat(bdma_chan);
659 		spin_lock(&bdma_chan->lock);
660 		desc = bdma_chan->active_tx;
661 
662 		if (desc->sg_len == 0) {
663 			dma_async_tx_callback callback = NULL;
664 			void *param = NULL;
665 
666 			desc->status = DMA_COMPLETE;
667 			dma_cookie_complete(&desc->txd);
668 			if (desc->txd.flags & DMA_PREP_INTERRUPT) {
669 				callback = desc->txd.callback;
670 				param = desc->txd.callback_param;
671 			}
672 			list_add(&desc->desc_node, &bdma_chan->free_list);
673 			bdma_chan->active_tx = NULL;
674 			if (bdma_chan->active)
675 				tsi721_advance_work(bdma_chan, NULL);
676 			spin_unlock(&bdma_chan->lock);
677 			if (callback)
678 				callback(param);
679 		} else {
680 			if (bdma_chan->active)
681 				tsi721_advance_work(bdma_chan,
682 						    bdma_chan->active_tx);
683 			spin_unlock(&bdma_chan->lock);
684 		}
685 	}
686 err_out:
687 	/* Re-Enable BDMA channel interrupts */
688 	iowrite32(TSI721_DMAC_INT_ALL, bdma_chan->regs + TSI721_DMAC_INTE);
689 }
690 
691 static dma_cookie_t tsi721_tx_submit(struct dma_async_tx_descriptor *txd)
692 {
693 	struct tsi721_tx_desc *desc = to_tsi721_desc(txd);
694 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(txd->chan);
695 	dma_cookie_t cookie;
696 
697 	/* Check if the descriptor is detached from any lists */
698 	if (!list_empty(&desc->desc_node)) {
699 		tsi_err(&bdma_chan->dchan.dev->device,
700 			"DMAC%d wrong state of descriptor %p",
701 			bdma_chan->id, txd);
702 		return -EIO;
703 	}
704 
705 	spin_lock_bh(&bdma_chan->lock);
706 
707 	if (!bdma_chan->active) {
708 		spin_unlock_bh(&bdma_chan->lock);
709 		return -ENODEV;
710 	}
711 
712 	cookie = dma_cookie_assign(txd);
713 	desc->status = DMA_IN_PROGRESS;
714 	list_add_tail(&desc->desc_node, &bdma_chan->queue);
715 	tsi721_advance_work(bdma_chan, NULL);
716 
717 	spin_unlock_bh(&bdma_chan->lock);
718 	return cookie;
719 }
720 
721 static int tsi721_alloc_chan_resources(struct dma_chan *dchan)
722 {
723 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
724 	struct tsi721_tx_desc *desc;
725 	int i;
726 
727 	tsi_debug(DMA, &dchan->dev->device, "DMAC%d", bdma_chan->id);
728 
729 	if (bdma_chan->bd_base)
730 		return dma_txqueue_sz;
731 
732 	/* Initialize BDMA channel */
733 	if (tsi721_bdma_ch_init(bdma_chan, dma_desc_per_channel)) {
734 		tsi_err(&dchan->dev->device, "Unable to initialize DMAC%d",
735 			bdma_chan->id);
736 		return -ENODEV;
737 	}
738 
739 	/* Allocate queue of transaction descriptors */
740 	desc = kcalloc(dma_txqueue_sz, sizeof(struct tsi721_tx_desc),
741 			GFP_ATOMIC);
742 	if (!desc) {
743 		tsi721_bdma_ch_free(bdma_chan);
744 		return -ENOMEM;
745 	}
746 
747 	bdma_chan->tx_desc = desc;
748 
749 	for (i = 0; i < dma_txqueue_sz; i++) {
750 		dma_async_tx_descriptor_init(&desc[i].txd, dchan);
751 		desc[i].txd.tx_submit = tsi721_tx_submit;
752 		desc[i].txd.flags = DMA_CTRL_ACK;
753 		list_add(&desc[i].desc_node, &bdma_chan->free_list);
754 	}
755 
756 	dma_cookie_init(dchan);
757 
758 	bdma_chan->active = true;
759 	tsi721_bdma_interrupt_enable(bdma_chan, 1);
760 
761 	return dma_txqueue_sz;
762 }
763 
764 static void tsi721_sync_dma_irq(struct tsi721_bdma_chan *bdma_chan)
765 {
766 	struct tsi721_device *priv = to_tsi721(bdma_chan->dchan.device);
767 
768 #ifdef CONFIG_PCI_MSI
769 	if (priv->flags & TSI721_USING_MSIX) {
770 		synchronize_irq(priv->msix[TSI721_VECT_DMA0_DONE +
771 					   bdma_chan->id].vector);
772 		synchronize_irq(priv->msix[TSI721_VECT_DMA0_INT +
773 					   bdma_chan->id].vector);
774 	} else
775 #endif
776 	synchronize_irq(priv->pdev->irq);
777 }
778 
779 static void tsi721_free_chan_resources(struct dma_chan *dchan)
780 {
781 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
782 
783 	tsi_debug(DMA, &dchan->dev->device, "DMAC%d", bdma_chan->id);
784 
785 	if (!bdma_chan->bd_base)
786 		return;
787 
788 	tsi721_bdma_interrupt_enable(bdma_chan, 0);
789 	bdma_chan->active = false;
790 	tsi721_sync_dma_irq(bdma_chan);
791 	tasklet_kill(&bdma_chan->tasklet);
792 	INIT_LIST_HEAD(&bdma_chan->free_list);
793 	kfree(bdma_chan->tx_desc);
794 	tsi721_bdma_ch_free(bdma_chan);
795 }
796 
797 static
798 enum dma_status tsi721_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
799 				 struct dma_tx_state *txstate)
800 {
801 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
802 	enum dma_status	status;
803 
804 	spin_lock_bh(&bdma_chan->lock);
805 	status = dma_cookie_status(dchan, cookie, txstate);
806 	spin_unlock_bh(&bdma_chan->lock);
807 	return status;
808 }
809 
810 static void tsi721_issue_pending(struct dma_chan *dchan)
811 {
812 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
813 
814 	tsi_debug(DMA, &dchan->dev->device, "DMAC%d", bdma_chan->id);
815 
816 	spin_lock_bh(&bdma_chan->lock);
817 	if (tsi721_dma_is_idle(bdma_chan) && bdma_chan->active) {
818 		tsi721_advance_work(bdma_chan, NULL);
819 	}
820 	spin_unlock_bh(&bdma_chan->lock);
821 }
822 
823 static
824 struct dma_async_tx_descriptor *tsi721_prep_rio_sg(struct dma_chan *dchan,
825 			struct scatterlist *sgl, unsigned int sg_len,
826 			enum dma_transfer_direction dir, unsigned long flags,
827 			void *tinfo)
828 {
829 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
830 	struct tsi721_tx_desc *desc;
831 	struct rio_dma_ext *rext = tinfo;
832 	enum dma_rtype rtype;
833 	struct dma_async_tx_descriptor *txd = NULL;
834 
835 	if (!sgl || !sg_len) {
836 		tsi_err(&dchan->dev->device, "DMAC%d No SG list",
837 			bdma_chan->id);
838 		return ERR_PTR(-EINVAL);
839 	}
840 
841 	tsi_debug(DMA, &dchan->dev->device, "DMAC%d %s", bdma_chan->id,
842 		  (dir == DMA_DEV_TO_MEM)?"READ":"WRITE");
843 
844 	if (dir == DMA_DEV_TO_MEM)
845 		rtype = NREAD;
846 	else if (dir == DMA_MEM_TO_DEV) {
847 		switch (rext->wr_type) {
848 		case RDW_ALL_NWRITE:
849 			rtype = ALL_NWRITE;
850 			break;
851 		case RDW_ALL_NWRITE_R:
852 			rtype = ALL_NWRITE_R;
853 			break;
854 		case RDW_LAST_NWRITE_R:
855 		default:
856 			rtype = LAST_NWRITE_R;
857 			break;
858 		}
859 	} else {
860 		tsi_err(&dchan->dev->device,
861 			"DMAC%d Unsupported DMA direction option",
862 			bdma_chan->id);
863 		return ERR_PTR(-EINVAL);
864 	}
865 
866 	spin_lock_bh(&bdma_chan->lock);
867 
868 	if (!list_empty(&bdma_chan->free_list)) {
869 		desc = list_first_entry(&bdma_chan->free_list,
870 				struct tsi721_tx_desc, desc_node);
871 		list_del_init(&desc->desc_node);
872 		desc->destid = rext->destid;
873 		desc->rio_addr = rext->rio_addr;
874 		desc->rio_addr_u = 0;
875 		desc->rtype = rtype;
876 		desc->sg_len	= sg_len;
877 		desc->sg	= sgl;
878 		txd		= &desc->txd;
879 		txd->flags	= flags;
880 	}
881 
882 	spin_unlock_bh(&bdma_chan->lock);
883 
884 	if (!txd) {
885 		tsi_debug(DMA, &dchan->dev->device,
886 			  "DMAC%d free TXD is not available", bdma_chan->id);
887 		return ERR_PTR(-EBUSY);
888 	}
889 
890 	return txd;
891 }
892 
893 static int tsi721_terminate_all(struct dma_chan *dchan)
894 {
895 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
896 	struct tsi721_tx_desc *desc, *_d;
897 	LIST_HEAD(list);
898 
899 	tsi_debug(DMA, &dchan->dev->device, "DMAC%d", bdma_chan->id);
900 
901 	spin_lock_bh(&bdma_chan->lock);
902 
903 	bdma_chan->active = false;
904 
905 	while (!tsi721_dma_is_idle(bdma_chan)) {
906 
907 		udelay(5);
908 #if (0)
909 		/* make sure to stop the transfer */
910 		iowrite32(TSI721_DMAC_CTL_SUSP,
911 			  bdma_chan->regs + TSI721_DMAC_CTL);
912 
913 		/* Wait until DMA channel stops */
914 		do {
915 			dmac_int = ioread32(bdma_chan->regs + TSI721_DMAC_INT);
916 		} while ((dmac_int & TSI721_DMAC_INT_SUSP) == 0);
917 #endif
918 	}
919 
920 	if (bdma_chan->active_tx)
921 		list_add(&bdma_chan->active_tx->desc_node, &list);
922 	list_splice_init(&bdma_chan->queue, &list);
923 
924 	list_for_each_entry_safe(desc, _d, &list, desc_node)
925 		tsi721_dma_tx_err(bdma_chan, desc);
926 
927 	spin_unlock_bh(&bdma_chan->lock);
928 
929 	return 0;
930 }
931 
932 static void tsi721_dma_stop(struct tsi721_bdma_chan *bdma_chan)
933 {
934 	if (!bdma_chan->active)
935 		return;
936 	spin_lock_bh(&bdma_chan->lock);
937 	if (!tsi721_dma_is_idle(bdma_chan)) {
938 		int timeout = 100000;
939 
940 		/* stop the transfer in progress */
941 		iowrite32(TSI721_DMAC_CTL_SUSP,
942 			  bdma_chan->regs + TSI721_DMAC_CTL);
943 
944 		/* Wait until DMA channel stops */
945 		while (!tsi721_dma_is_idle(bdma_chan) && --timeout)
946 			udelay(1);
947 	}
948 
949 	spin_unlock_bh(&bdma_chan->lock);
950 }
951 
952 void tsi721_dma_stop_all(struct tsi721_device *priv)
953 {
954 	int i;
955 
956 	for (i = 0; i < TSI721_DMA_MAXCH; i++) {
957 		if ((i != TSI721_DMACH_MAINT) && (dma_sel & (1 << i)))
958 			tsi721_dma_stop(&priv->bdma[i]);
959 	}
960 }
961 
962 int tsi721_register_dma(struct tsi721_device *priv)
963 {
964 	int i;
965 	int nr_channels = 0;
966 	int err;
967 	struct rio_mport *mport = &priv->mport;
968 
969 	INIT_LIST_HEAD(&mport->dma.channels);
970 
971 	for (i = 0; i < TSI721_DMA_MAXCH; i++) {
972 		struct tsi721_bdma_chan *bdma_chan = &priv->bdma[i];
973 
974 		if ((i == TSI721_DMACH_MAINT) || (dma_sel & (1 << i)) == 0)
975 			continue;
976 
977 		bdma_chan->regs = priv->regs + TSI721_DMAC_BASE(i);
978 
979 		bdma_chan->dchan.device = &mport->dma;
980 		bdma_chan->dchan.cookie = 1;
981 		bdma_chan->dchan.chan_id = i;
982 		bdma_chan->id = i;
983 		bdma_chan->active = false;
984 
985 		spin_lock_init(&bdma_chan->lock);
986 
987 		bdma_chan->active_tx = NULL;
988 		INIT_LIST_HEAD(&bdma_chan->queue);
989 		INIT_LIST_HEAD(&bdma_chan->free_list);
990 
991 		tasklet_init(&bdma_chan->tasklet, tsi721_dma_tasklet,
992 			     (unsigned long)bdma_chan);
993 		list_add_tail(&bdma_chan->dchan.device_node,
994 			      &mport->dma.channels);
995 		nr_channels++;
996 	}
997 
998 	mport->dma.chancnt = nr_channels;
999 	dma_cap_zero(mport->dma.cap_mask);
1000 	dma_cap_set(DMA_PRIVATE, mport->dma.cap_mask);
1001 	dma_cap_set(DMA_SLAVE, mport->dma.cap_mask);
1002 
1003 	mport->dma.dev = &priv->pdev->dev;
1004 	mport->dma.device_alloc_chan_resources = tsi721_alloc_chan_resources;
1005 	mport->dma.device_free_chan_resources = tsi721_free_chan_resources;
1006 	mport->dma.device_tx_status = tsi721_tx_status;
1007 	mport->dma.device_issue_pending = tsi721_issue_pending;
1008 	mport->dma.device_prep_slave_sg = tsi721_prep_rio_sg;
1009 	mport->dma.device_terminate_all = tsi721_terminate_all;
1010 
1011 	err = dma_async_device_register(&mport->dma);
1012 	if (err)
1013 		tsi_err(&priv->pdev->dev, "Failed to register DMA device");
1014 
1015 	return err;
1016 }
1017 
1018 void tsi721_unregister_dma(struct tsi721_device *priv)
1019 {
1020 	struct rio_mport *mport = &priv->mport;
1021 	struct dma_chan *chan, *_c;
1022 	struct tsi721_bdma_chan *bdma_chan;
1023 
1024 	tsi721_dma_stop_all(priv);
1025 	dma_async_device_unregister(&mport->dma);
1026 
1027 	list_for_each_entry_safe(chan, _c, &mport->dma.channels,
1028 					device_node) {
1029 		bdma_chan = to_tsi721_chan(chan);
1030 		if (bdma_chan->active) {
1031 			tsi721_bdma_interrupt_enable(bdma_chan, 0);
1032 			bdma_chan->active = false;
1033 			tsi721_sync_dma_irq(bdma_chan);
1034 			tasklet_kill(&bdma_chan->tasklet);
1035 			INIT_LIST_HEAD(&bdma_chan->free_list);
1036 			kfree(bdma_chan->tx_desc);
1037 			tsi721_bdma_ch_free(bdma_chan);
1038 		}
1039 
1040 		list_del(&chan->device_node);
1041 	}
1042 }
1043