xref: /openbmc/linux/drivers/net/ethernet/ibm/emac/mal.c (revision 6db6b729)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * drivers/net/ethernet/ibm/emac/mal.c
4  *
5  * Memory Access Layer (MAL) support
6  *
7  * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
8  *                <benh@kernel.crashing.org>
9  *
10  * Based on the arch/ppc version of the driver:
11  *
12  * Copyright (c) 2004, 2005 Zultys Technologies.
13  * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
14  *
15  * Based on original work by
16  *      Benjamin Herrenschmidt <benh@kernel.crashing.org>,
17  *      David Gibson <hermes@gibson.dropbear.id.au>,
18  *
19  *      Armin Kuster <akuster@mvista.com>
20  *      Copyright 2002 MontaVista Softare Inc.
21  */
22 
23 #include <linux/delay.h>
24 #include <linux/slab.h>
25 #include <linux/of.h>
26 #include <linux/of_irq.h>
27 #include <linux/platform_device.h>
28 
29 #include "core.h"
30 #include <asm/dcr-regs.h>
31 
32 static int mal_count;
33 
34 int mal_register_commac(struct mal_instance *mal, struct mal_commac *commac)
35 {
36 	unsigned long flags;
37 
38 	spin_lock_irqsave(&mal->lock, flags);
39 
40 	MAL_DBG(mal, "reg(%08x, %08x)" NL,
41 		commac->tx_chan_mask, commac->rx_chan_mask);
42 
43 	/* Don't let multiple commacs claim the same channel(s) */
44 	if ((mal->tx_chan_mask & commac->tx_chan_mask) ||
45 	    (mal->rx_chan_mask & commac->rx_chan_mask)) {
46 		spin_unlock_irqrestore(&mal->lock, flags);
47 		printk(KERN_WARNING "mal%d: COMMAC channels conflict!\n",
48 		       mal->index);
49 		return -EBUSY;
50 	}
51 
52 	if (list_empty(&mal->list))
53 		napi_enable(&mal->napi);
54 	mal->tx_chan_mask |= commac->tx_chan_mask;
55 	mal->rx_chan_mask |= commac->rx_chan_mask;
56 	list_add(&commac->list, &mal->list);
57 
58 	spin_unlock_irqrestore(&mal->lock, flags);
59 
60 	return 0;
61 }
62 
63 void mal_unregister_commac(struct mal_instance	*mal,
64 		struct mal_commac *commac)
65 {
66 	unsigned long flags;
67 
68 	spin_lock_irqsave(&mal->lock, flags);
69 
70 	MAL_DBG(mal, "unreg(%08x, %08x)" NL,
71 		commac->tx_chan_mask, commac->rx_chan_mask);
72 
73 	mal->tx_chan_mask &= ~commac->tx_chan_mask;
74 	mal->rx_chan_mask &= ~commac->rx_chan_mask;
75 	list_del_init(&commac->list);
76 	if (list_empty(&mal->list))
77 		napi_disable(&mal->napi);
78 
79 	spin_unlock_irqrestore(&mal->lock, flags);
80 }
81 
82 int mal_set_rcbs(struct mal_instance *mal, int channel, unsigned long size)
83 {
84 	BUG_ON(channel < 0 || channel >= mal->num_rx_chans ||
85 	       size > MAL_MAX_RX_SIZE);
86 
87 	MAL_DBG(mal, "set_rbcs(%d, %lu)" NL, channel, size);
88 
89 	if (size & 0xf) {
90 		printk(KERN_WARNING
91 		       "mal%d: incorrect RX size %lu for the channel %d\n",
92 		       mal->index, size, channel);
93 		return -EINVAL;
94 	}
95 
96 	set_mal_dcrn(mal, MAL_RCBS(channel), size >> 4);
97 	return 0;
98 }
99 
100 int mal_tx_bd_offset(struct mal_instance *mal, int channel)
101 {
102 	BUG_ON(channel < 0 || channel >= mal->num_tx_chans);
103 
104 	return channel * NUM_TX_BUFF;
105 }
106 
107 int mal_rx_bd_offset(struct mal_instance *mal, int channel)
108 {
109 	BUG_ON(channel < 0 || channel >= mal->num_rx_chans);
110 	return mal->num_tx_chans * NUM_TX_BUFF + channel * NUM_RX_BUFF;
111 }
112 
113 void mal_enable_tx_channel(struct mal_instance *mal, int channel)
114 {
115 	unsigned long flags;
116 
117 	spin_lock_irqsave(&mal->lock, flags);
118 
119 	MAL_DBG(mal, "enable_tx(%d)" NL, channel);
120 
121 	set_mal_dcrn(mal, MAL_TXCASR,
122 		     get_mal_dcrn(mal, MAL_TXCASR) | MAL_CHAN_MASK(channel));
123 
124 	spin_unlock_irqrestore(&mal->lock, flags);
125 }
126 
127 void mal_disable_tx_channel(struct mal_instance *mal, int channel)
128 {
129 	set_mal_dcrn(mal, MAL_TXCARR, MAL_CHAN_MASK(channel));
130 
131 	MAL_DBG(mal, "disable_tx(%d)" NL, channel);
132 }
133 
134 void mal_enable_rx_channel(struct mal_instance *mal, int channel)
135 {
136 	unsigned long flags;
137 
138 	/*
139 	 * On some 4xx PPC's (e.g. 460EX/GT), the rx channel is a multiple
140 	 * of 8, but enabling in MAL_RXCASR needs the divided by 8 value
141 	 * for the bitmask
142 	 */
143 	if (!(channel % 8))
144 		channel >>= 3;
145 
146 	spin_lock_irqsave(&mal->lock, flags);
147 
148 	MAL_DBG(mal, "enable_rx(%d)" NL, channel);
149 
150 	set_mal_dcrn(mal, MAL_RXCASR,
151 		     get_mal_dcrn(mal, MAL_RXCASR) | MAL_CHAN_MASK(channel));
152 
153 	spin_unlock_irqrestore(&mal->lock, flags);
154 }
155 
156 void mal_disable_rx_channel(struct mal_instance *mal, int channel)
157 {
158 	/*
159 	 * On some 4xx PPC's (e.g. 460EX/GT), the rx channel is a multiple
160 	 * of 8, but enabling in MAL_RXCASR needs the divided by 8 value
161 	 * for the bitmask
162 	 */
163 	if (!(channel % 8))
164 		channel >>= 3;
165 
166 	set_mal_dcrn(mal, MAL_RXCARR, MAL_CHAN_MASK(channel));
167 
168 	MAL_DBG(mal, "disable_rx(%d)" NL, channel);
169 }
170 
171 void mal_poll_add(struct mal_instance *mal, struct mal_commac *commac)
172 {
173 	unsigned long flags;
174 
175 	spin_lock_irqsave(&mal->lock, flags);
176 
177 	MAL_DBG(mal, "poll_add(%p)" NL, commac);
178 
179 	/* starts disabled */
180 	set_bit(MAL_COMMAC_POLL_DISABLED, &commac->flags);
181 
182 	list_add_tail(&commac->poll_list, &mal->poll_list);
183 
184 	spin_unlock_irqrestore(&mal->lock, flags);
185 }
186 
187 void mal_poll_del(struct mal_instance *mal, struct mal_commac *commac)
188 {
189 	unsigned long flags;
190 
191 	spin_lock_irqsave(&mal->lock, flags);
192 
193 	MAL_DBG(mal, "poll_del(%p)" NL, commac);
194 
195 	list_del(&commac->poll_list);
196 
197 	spin_unlock_irqrestore(&mal->lock, flags);
198 }
199 
200 /* synchronized by mal_poll() */
201 static inline void mal_enable_eob_irq(struct mal_instance *mal)
202 {
203 	MAL_DBG2(mal, "enable_irq" NL);
204 
205 	// XXX might want to cache MAL_CFG as the DCR read can be slooooow
206 	set_mal_dcrn(mal, MAL_CFG, get_mal_dcrn(mal, MAL_CFG) | MAL_CFG_EOPIE);
207 }
208 
209 /* synchronized by NAPI state */
210 static inline void mal_disable_eob_irq(struct mal_instance *mal)
211 {
212 	// XXX might want to cache MAL_CFG as the DCR read can be slooooow
213 	set_mal_dcrn(mal, MAL_CFG, get_mal_dcrn(mal, MAL_CFG) & ~MAL_CFG_EOPIE);
214 
215 	MAL_DBG2(mal, "disable_irq" NL);
216 }
217 
218 static irqreturn_t mal_serr(int irq, void *dev_instance)
219 {
220 	struct mal_instance *mal = dev_instance;
221 
222 	u32 esr = get_mal_dcrn(mal, MAL_ESR);
223 
224 	/* Clear the error status register */
225 	set_mal_dcrn(mal, MAL_ESR, esr);
226 
227 	MAL_DBG(mal, "SERR %08x" NL, esr);
228 
229 	if (esr & MAL_ESR_EVB) {
230 		if (esr & MAL_ESR_DE) {
231 			/* We ignore Descriptor error,
232 			 * TXDE or RXDE interrupt will be generated anyway.
233 			 */
234 			return IRQ_HANDLED;
235 		}
236 
237 		if (esr & MAL_ESR_PEIN) {
238 			/* PLB error, it's probably buggy hardware or
239 			 * incorrect physical address in BD (i.e. bug)
240 			 */
241 			if (net_ratelimit())
242 				printk(KERN_ERR
243 				       "mal%d: system error, "
244 				       "PLB (ESR = 0x%08x)\n",
245 				       mal->index, esr);
246 			return IRQ_HANDLED;
247 		}
248 
249 		/* OPB error, it's probably buggy hardware or incorrect
250 		 * EBC setup
251 		 */
252 		if (net_ratelimit())
253 			printk(KERN_ERR
254 			       "mal%d: system error, OPB (ESR = 0x%08x)\n",
255 			       mal->index, esr);
256 	}
257 	return IRQ_HANDLED;
258 }
259 
260 static inline void mal_schedule_poll(struct mal_instance *mal)
261 {
262 	if (likely(napi_schedule_prep(&mal->napi))) {
263 		MAL_DBG2(mal, "schedule_poll" NL);
264 		spin_lock(&mal->lock);
265 		mal_disable_eob_irq(mal);
266 		spin_unlock(&mal->lock);
267 		__napi_schedule(&mal->napi);
268 	} else
269 		MAL_DBG2(mal, "already in poll" NL);
270 }
271 
272 static irqreturn_t mal_txeob(int irq, void *dev_instance)
273 {
274 	struct mal_instance *mal = dev_instance;
275 
276 	u32 r = get_mal_dcrn(mal, MAL_TXEOBISR);
277 
278 	MAL_DBG2(mal, "txeob %08x" NL, r);
279 
280 	mal_schedule_poll(mal);
281 	set_mal_dcrn(mal, MAL_TXEOBISR, r);
282 
283 #ifdef CONFIG_PPC_DCR_NATIVE
284 	if (mal_has_feature(mal, MAL_FTR_CLEAR_ICINTSTAT))
285 		mtdcri(SDR0, DCRN_SDR_ICINTSTAT,
286 				(mfdcri(SDR0, DCRN_SDR_ICINTSTAT) | ICINTSTAT_ICTX));
287 #endif
288 
289 	return IRQ_HANDLED;
290 }
291 
292 static irqreturn_t mal_rxeob(int irq, void *dev_instance)
293 {
294 	struct mal_instance *mal = dev_instance;
295 
296 	u32 r = get_mal_dcrn(mal, MAL_RXEOBISR);
297 
298 	MAL_DBG2(mal, "rxeob %08x" NL, r);
299 
300 	mal_schedule_poll(mal);
301 	set_mal_dcrn(mal, MAL_RXEOBISR, r);
302 
303 #ifdef CONFIG_PPC_DCR_NATIVE
304 	if (mal_has_feature(mal, MAL_FTR_CLEAR_ICINTSTAT))
305 		mtdcri(SDR0, DCRN_SDR_ICINTSTAT,
306 				(mfdcri(SDR0, DCRN_SDR_ICINTSTAT) | ICINTSTAT_ICRX));
307 #endif
308 
309 	return IRQ_HANDLED;
310 }
311 
312 static irqreturn_t mal_txde(int irq, void *dev_instance)
313 {
314 	struct mal_instance *mal = dev_instance;
315 
316 	u32 deir = get_mal_dcrn(mal, MAL_TXDEIR);
317 	set_mal_dcrn(mal, MAL_TXDEIR, deir);
318 
319 	MAL_DBG(mal, "txde %08x" NL, deir);
320 
321 	if (net_ratelimit())
322 		printk(KERN_ERR
323 		       "mal%d: TX descriptor error (TXDEIR = 0x%08x)\n",
324 		       mal->index, deir);
325 
326 	return IRQ_HANDLED;
327 }
328 
329 static irqreturn_t mal_rxde(int irq, void *dev_instance)
330 {
331 	struct mal_instance *mal = dev_instance;
332 	struct list_head *l;
333 
334 	u32 deir = get_mal_dcrn(mal, MAL_RXDEIR);
335 
336 	MAL_DBG(mal, "rxde %08x" NL, deir);
337 
338 	list_for_each(l, &mal->list) {
339 		struct mal_commac *mc = list_entry(l, struct mal_commac, list);
340 		if (deir & mc->rx_chan_mask) {
341 			set_bit(MAL_COMMAC_RX_STOPPED, &mc->flags);
342 			mc->ops->rxde(mc->dev);
343 		}
344 	}
345 
346 	mal_schedule_poll(mal);
347 	set_mal_dcrn(mal, MAL_RXDEIR, deir);
348 
349 	return IRQ_HANDLED;
350 }
351 
352 static irqreturn_t mal_int(int irq, void *dev_instance)
353 {
354 	struct mal_instance *mal = dev_instance;
355 	u32 esr = get_mal_dcrn(mal, MAL_ESR);
356 
357 	if (esr & MAL_ESR_EVB) {
358 		/* descriptor error */
359 		if (esr & MAL_ESR_DE) {
360 			if (esr & MAL_ESR_CIDT)
361 				return mal_rxde(irq, dev_instance);
362 			else
363 				return mal_txde(irq, dev_instance);
364 		} else { /* SERR */
365 			return mal_serr(irq, dev_instance);
366 		}
367 	}
368 	return IRQ_HANDLED;
369 }
370 
371 void mal_poll_disable(struct mal_instance *mal, struct mal_commac *commac)
372 {
373 	/* Spinlock-type semantics: only one caller disable poll at a time */
374 	while (test_and_set_bit(MAL_COMMAC_POLL_DISABLED, &commac->flags))
375 		msleep(1);
376 
377 	/* Synchronize with the MAL NAPI poller */
378 	napi_synchronize(&mal->napi);
379 }
380 
381 void mal_poll_enable(struct mal_instance *mal, struct mal_commac *commac)
382 {
383 	smp_wmb();
384 	clear_bit(MAL_COMMAC_POLL_DISABLED, &commac->flags);
385 
386 	/* Feels better to trigger a poll here to catch up with events that
387 	 * may have happened on this channel while disabled. It will most
388 	 * probably be delayed until the next interrupt but that's mostly a
389 	 * non-issue in the context where this is called.
390 	 */
391 	napi_schedule(&mal->napi);
392 }
393 
394 static int mal_poll(struct napi_struct *napi, int budget)
395 {
396 	struct mal_instance *mal = container_of(napi, struct mal_instance, napi);
397 	struct list_head *l;
398 	int received = 0;
399 	unsigned long flags;
400 
401 	MAL_DBG2(mal, "poll(%d)" NL, budget);
402 
403 	/* Process TX skbs */
404 	list_for_each(l, &mal->poll_list) {
405 		struct mal_commac *mc =
406 			list_entry(l, struct mal_commac, poll_list);
407 		mc->ops->poll_tx(mc->dev);
408 	}
409 
410 	/* Process RX skbs.
411 	 *
412 	 * We _might_ need something more smart here to enforce polling
413 	 * fairness.
414 	 */
415 	list_for_each(l, &mal->poll_list) {
416 		struct mal_commac *mc =
417 			list_entry(l, struct mal_commac, poll_list);
418 		int n;
419 		if (unlikely(test_bit(MAL_COMMAC_POLL_DISABLED, &mc->flags)))
420 			continue;
421 		n = mc->ops->poll_rx(mc->dev, budget - received);
422 		if (n) {
423 			received += n;
424 			if (received >= budget)
425 				return budget;
426 		}
427 	}
428 
429 	if (napi_complete_done(napi, received)) {
430 		/* We need to disable IRQs to protect from RXDE IRQ here */
431 		spin_lock_irqsave(&mal->lock, flags);
432 		mal_enable_eob_irq(mal);
433 		spin_unlock_irqrestore(&mal->lock, flags);
434 	}
435 
436 	/* Check for "rotting" packet(s) */
437 	list_for_each(l, &mal->poll_list) {
438 		struct mal_commac *mc =
439 			list_entry(l, struct mal_commac, poll_list);
440 		if (unlikely(test_bit(MAL_COMMAC_POLL_DISABLED, &mc->flags)))
441 			continue;
442 		if (unlikely(mc->ops->peek_rx(mc->dev) ||
443 			     test_bit(MAL_COMMAC_RX_STOPPED, &mc->flags))) {
444 			MAL_DBG2(mal, "rotting packet" NL);
445 			if (!napi_reschedule(napi))
446 				goto more_work;
447 
448 			spin_lock_irqsave(&mal->lock, flags);
449 			mal_disable_eob_irq(mal);
450 			spin_unlock_irqrestore(&mal->lock, flags);
451 		}
452 		mc->ops->poll_tx(mc->dev);
453 	}
454 
455  more_work:
456 	MAL_DBG2(mal, "poll() %d <- %d" NL, budget, received);
457 	return received;
458 }
459 
460 static void mal_reset(struct mal_instance *mal)
461 {
462 	int n = 10;
463 
464 	MAL_DBG(mal, "reset" NL);
465 
466 	set_mal_dcrn(mal, MAL_CFG, MAL_CFG_SR);
467 
468 	/* Wait for reset to complete (1 system clock) */
469 	while ((get_mal_dcrn(mal, MAL_CFG) & MAL_CFG_SR) && n)
470 		--n;
471 
472 	if (unlikely(!n))
473 		printk(KERN_ERR "mal%d: reset timeout\n", mal->index);
474 }
475 
476 int mal_get_regs_len(struct mal_instance *mal)
477 {
478 	return sizeof(struct emac_ethtool_regs_subhdr) +
479 	    sizeof(struct mal_regs);
480 }
481 
482 void *mal_dump_regs(struct mal_instance *mal, void *buf)
483 {
484 	struct emac_ethtool_regs_subhdr *hdr = buf;
485 	struct mal_regs *regs = (struct mal_regs *)(hdr + 1);
486 	int i;
487 
488 	hdr->version = mal->version;
489 	hdr->index = mal->index;
490 
491 	regs->tx_count = mal->num_tx_chans;
492 	regs->rx_count = mal->num_rx_chans;
493 
494 	regs->cfg = get_mal_dcrn(mal, MAL_CFG);
495 	regs->esr = get_mal_dcrn(mal, MAL_ESR);
496 	regs->ier = get_mal_dcrn(mal, MAL_IER);
497 	regs->tx_casr = get_mal_dcrn(mal, MAL_TXCASR);
498 	regs->tx_carr = get_mal_dcrn(mal, MAL_TXCARR);
499 	regs->tx_eobisr = get_mal_dcrn(mal, MAL_TXEOBISR);
500 	regs->tx_deir = get_mal_dcrn(mal, MAL_TXDEIR);
501 	regs->rx_casr = get_mal_dcrn(mal, MAL_RXCASR);
502 	regs->rx_carr = get_mal_dcrn(mal, MAL_RXCARR);
503 	regs->rx_eobisr = get_mal_dcrn(mal, MAL_RXEOBISR);
504 	regs->rx_deir = get_mal_dcrn(mal, MAL_RXDEIR);
505 
506 	for (i = 0; i < regs->tx_count; ++i)
507 		regs->tx_ctpr[i] = get_mal_dcrn(mal, MAL_TXCTPR(i));
508 
509 	for (i = 0; i < regs->rx_count; ++i) {
510 		regs->rx_ctpr[i] = get_mal_dcrn(mal, MAL_RXCTPR(i));
511 		regs->rcbs[i] = get_mal_dcrn(mal, MAL_RCBS(i));
512 	}
513 	return regs + 1;
514 }
515 
516 static int mal_probe(struct platform_device *ofdev)
517 {
518 	struct mal_instance *mal;
519 	int err = 0, i, bd_size;
520 	int index = mal_count++;
521 	unsigned int dcr_base;
522 	const u32 *prop;
523 	u32 cfg;
524 	unsigned long irqflags;
525 	irq_handler_t hdlr_serr, hdlr_txde, hdlr_rxde;
526 
527 	mal = kzalloc(sizeof(struct mal_instance), GFP_KERNEL);
528 	if (!mal)
529 		return -ENOMEM;
530 
531 	mal->index = index;
532 	mal->ofdev = ofdev;
533 	mal->version = of_device_is_compatible(ofdev->dev.of_node, "ibm,mcmal2") ? 2 : 1;
534 
535 	MAL_DBG(mal, "probe" NL);
536 
537 	prop = of_get_property(ofdev->dev.of_node, "num-tx-chans", NULL);
538 	if (prop == NULL) {
539 		printk(KERN_ERR
540 		       "mal%d: can't find MAL num-tx-chans property!\n",
541 		       index);
542 		err = -ENODEV;
543 		goto fail;
544 	}
545 	mal->num_tx_chans = prop[0];
546 
547 	prop = of_get_property(ofdev->dev.of_node, "num-rx-chans", NULL);
548 	if (prop == NULL) {
549 		printk(KERN_ERR
550 		       "mal%d: can't find MAL num-rx-chans property!\n",
551 		       index);
552 		err = -ENODEV;
553 		goto fail;
554 	}
555 	mal->num_rx_chans = prop[0];
556 
557 	dcr_base = dcr_resource_start(ofdev->dev.of_node, 0);
558 	if (dcr_base == 0) {
559 		printk(KERN_ERR
560 		       "mal%d: can't find DCR resource!\n", index);
561 		err = -ENODEV;
562 		goto fail;
563 	}
564 	mal->dcr_host = dcr_map(ofdev->dev.of_node, dcr_base, 0x100);
565 	if (!DCR_MAP_OK(mal->dcr_host)) {
566 		printk(KERN_ERR
567 		       "mal%d: failed to map DCRs !\n", index);
568 		err = -ENODEV;
569 		goto fail;
570 	}
571 
572 	if (of_device_is_compatible(ofdev->dev.of_node, "ibm,mcmal-405ez")) {
573 #if defined(CONFIG_IBM_EMAC_MAL_CLR_ICINTSTAT) && \
574 		defined(CONFIG_IBM_EMAC_MAL_COMMON_ERR)
575 		mal->features |= (MAL_FTR_CLEAR_ICINTSTAT |
576 				MAL_FTR_COMMON_ERR_INT);
577 #else
578 		printk(KERN_ERR "%pOF: Support for 405EZ not enabled!\n",
579 				ofdev->dev.of_node);
580 		err = -ENODEV;
581 		goto fail;
582 #endif
583 	}
584 
585 	mal->txeob_irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
586 	mal->rxeob_irq = irq_of_parse_and_map(ofdev->dev.of_node, 1);
587 	mal->serr_irq = irq_of_parse_and_map(ofdev->dev.of_node, 2);
588 
589 	if (mal_has_feature(mal, MAL_FTR_COMMON_ERR_INT)) {
590 		mal->txde_irq = mal->rxde_irq = mal->serr_irq;
591 	} else {
592 		mal->txde_irq = irq_of_parse_and_map(ofdev->dev.of_node, 3);
593 		mal->rxde_irq = irq_of_parse_and_map(ofdev->dev.of_node, 4);
594 	}
595 
596 	if (!mal->txeob_irq || !mal->rxeob_irq || !mal->serr_irq ||
597 	    !mal->txde_irq  || !mal->rxde_irq) {
598 		printk(KERN_ERR
599 		       "mal%d: failed to map interrupts !\n", index);
600 		err = -ENODEV;
601 		goto fail_unmap;
602 	}
603 
604 	INIT_LIST_HEAD(&mal->poll_list);
605 	INIT_LIST_HEAD(&mal->list);
606 	spin_lock_init(&mal->lock);
607 
608 	init_dummy_netdev(&mal->dummy_dev);
609 
610 	netif_napi_add_weight(&mal->dummy_dev, &mal->napi, mal_poll,
611 			      CONFIG_IBM_EMAC_POLL_WEIGHT);
612 
613 	/* Load power-on reset defaults */
614 	mal_reset(mal);
615 
616 	/* Set the MAL configuration register */
617 	cfg = (mal->version == 2) ? MAL2_CFG_DEFAULT : MAL1_CFG_DEFAULT;
618 	cfg |= MAL_CFG_PLBB | MAL_CFG_OPBBL | MAL_CFG_LEA;
619 
620 	/* Current Axon is not happy with priority being non-0, it can
621 	 * deadlock, fix it up here
622 	 */
623 	if (of_device_is_compatible(ofdev->dev.of_node, "ibm,mcmal-axon"))
624 		cfg &= ~(MAL2_CFG_RPP_10 | MAL2_CFG_WPP_10);
625 
626 	/* Apply configuration */
627 	set_mal_dcrn(mal, MAL_CFG, cfg);
628 
629 	/* Allocate space for BD rings */
630 	BUG_ON(mal->num_tx_chans <= 0 || mal->num_tx_chans > 32);
631 	BUG_ON(mal->num_rx_chans <= 0 || mal->num_rx_chans > 32);
632 
633 	bd_size = sizeof(struct mal_descriptor) *
634 		(NUM_TX_BUFF * mal->num_tx_chans +
635 		 NUM_RX_BUFF * mal->num_rx_chans);
636 	mal->bd_virt = dma_alloc_coherent(&ofdev->dev, bd_size, &mal->bd_dma,
637 					  GFP_KERNEL);
638 	if (mal->bd_virt == NULL) {
639 		err = -ENOMEM;
640 		goto fail_unmap;
641 	}
642 
643 	for (i = 0; i < mal->num_tx_chans; ++i)
644 		set_mal_dcrn(mal, MAL_TXCTPR(i), mal->bd_dma +
645 			     sizeof(struct mal_descriptor) *
646 			     mal_tx_bd_offset(mal, i));
647 
648 	for (i = 0; i < mal->num_rx_chans; ++i)
649 		set_mal_dcrn(mal, MAL_RXCTPR(i), mal->bd_dma +
650 			     sizeof(struct mal_descriptor) *
651 			     mal_rx_bd_offset(mal, i));
652 
653 	if (mal_has_feature(mal, MAL_FTR_COMMON_ERR_INT)) {
654 		irqflags = IRQF_SHARED;
655 		hdlr_serr = hdlr_txde = hdlr_rxde = mal_int;
656 	} else {
657 		irqflags = 0;
658 		hdlr_serr = mal_serr;
659 		hdlr_txde = mal_txde;
660 		hdlr_rxde = mal_rxde;
661 	}
662 
663 	err = request_irq(mal->serr_irq, hdlr_serr, irqflags, "MAL SERR", mal);
664 	if (err)
665 		goto fail2;
666 	err = request_irq(mal->txde_irq, hdlr_txde, irqflags, "MAL TX DE", mal);
667 	if (err)
668 		goto fail3;
669 	err = request_irq(mal->txeob_irq, mal_txeob, 0, "MAL TX EOB", mal);
670 	if (err)
671 		goto fail4;
672 	err = request_irq(mal->rxde_irq, hdlr_rxde, irqflags, "MAL RX DE", mal);
673 	if (err)
674 		goto fail5;
675 	err = request_irq(mal->rxeob_irq, mal_rxeob, 0, "MAL RX EOB", mal);
676 	if (err)
677 		goto fail6;
678 
679 	/* Enable all MAL SERR interrupt sources */
680 	set_mal_dcrn(mal, MAL_IER, MAL_IER_EVENTS);
681 
682 	/* Enable EOB interrupt */
683 	mal_enable_eob_irq(mal);
684 
685 	printk(KERN_INFO
686 	       "MAL v%d %pOF, %d TX channels, %d RX channels\n",
687 	       mal->version, ofdev->dev.of_node,
688 	       mal->num_tx_chans, mal->num_rx_chans);
689 
690 	/* Advertise this instance to the rest of the world */
691 	wmb();
692 	platform_set_drvdata(ofdev, mal);
693 
694 	return 0;
695 
696  fail6:
697 	free_irq(mal->rxde_irq, mal);
698  fail5:
699 	free_irq(mal->txeob_irq, mal);
700  fail4:
701 	free_irq(mal->txde_irq, mal);
702  fail3:
703 	free_irq(mal->serr_irq, mal);
704  fail2:
705 	dma_free_coherent(&ofdev->dev, bd_size, mal->bd_virt, mal->bd_dma);
706  fail_unmap:
707 	dcr_unmap(mal->dcr_host, 0x100);
708  fail:
709 	kfree(mal);
710 
711 	return err;
712 }
713 
714 static int mal_remove(struct platform_device *ofdev)
715 {
716 	struct mal_instance *mal = platform_get_drvdata(ofdev);
717 
718 	MAL_DBG(mal, "remove" NL);
719 
720 	/* Synchronize with scheduled polling */
721 	napi_disable(&mal->napi);
722 
723 	if (!list_empty(&mal->list))
724 		/* This is *very* bad */
725 		WARN(1, KERN_EMERG
726 		       "mal%d: commac list is not empty on remove!\n",
727 		       mal->index);
728 
729 	free_irq(mal->serr_irq, mal);
730 	free_irq(mal->txde_irq, mal);
731 	free_irq(mal->txeob_irq, mal);
732 	free_irq(mal->rxde_irq, mal);
733 	free_irq(mal->rxeob_irq, mal);
734 
735 	mal_reset(mal);
736 
737 	dma_free_coherent(&ofdev->dev,
738 			  sizeof(struct mal_descriptor) *
739 			  (NUM_TX_BUFF * mal->num_tx_chans +
740 			   NUM_RX_BUFF * mal->num_rx_chans), mal->bd_virt,
741 			  mal->bd_dma);
742 	kfree(mal);
743 
744 	return 0;
745 }
746 
747 static const struct of_device_id mal_platform_match[] =
748 {
749 	{
750 		.compatible	= "ibm,mcmal",
751 	},
752 	{
753 		.compatible	= "ibm,mcmal2",
754 	},
755 	/* Backward compat */
756 	{
757 		.type		= "mcmal-dma",
758 		.compatible	= "ibm,mcmal",
759 	},
760 	{
761 		.type		= "mcmal-dma",
762 		.compatible	= "ibm,mcmal2",
763 	},
764 	{},
765 };
766 
767 static struct platform_driver mal_of_driver = {
768 	.driver = {
769 		.name = "mcmal",
770 		.of_match_table = mal_platform_match,
771 	},
772 	.probe = mal_probe,
773 	.remove = mal_remove,
774 };
775 
776 int __init mal_init(void)
777 {
778 	return platform_driver_register(&mal_of_driver);
779 }
780 
781 void mal_exit(void)
782 {
783 	platform_driver_unregister(&mal_of_driver);
784 }
785