xref: /openbmc/linux/drivers/net/ethernet/ibm/emac/mal.c (revision 3a35093a)
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_irq.h>
26 
27 #include "core.h"
28 #include <asm/dcr-regs.h>
29 
30 static int mal_count;
31 
32 int mal_register_commac(struct mal_instance *mal, struct mal_commac *commac)
33 {
34 	unsigned long flags;
35 
36 	spin_lock_irqsave(&mal->lock, flags);
37 
38 	MAL_DBG(mal, "reg(%08x, %08x)" NL,
39 		commac->tx_chan_mask, commac->rx_chan_mask);
40 
41 	/* Don't let multiple commacs claim the same channel(s) */
42 	if ((mal->tx_chan_mask & commac->tx_chan_mask) ||
43 	    (mal->rx_chan_mask & commac->rx_chan_mask)) {
44 		spin_unlock_irqrestore(&mal->lock, flags);
45 		printk(KERN_WARNING "mal%d: COMMAC channels conflict!\n",
46 		       mal->index);
47 		return -EBUSY;
48 	}
49 
50 	if (list_empty(&mal->list))
51 		napi_enable(&mal->napi);
52 	mal->tx_chan_mask |= commac->tx_chan_mask;
53 	mal->rx_chan_mask |= commac->rx_chan_mask;
54 	list_add(&commac->list, &mal->list);
55 
56 	spin_unlock_irqrestore(&mal->lock, flags);
57 
58 	return 0;
59 }
60 
61 void mal_unregister_commac(struct mal_instance	*mal,
62 		struct mal_commac *commac)
63 {
64 	unsigned long flags;
65 
66 	spin_lock_irqsave(&mal->lock, flags);
67 
68 	MAL_DBG(mal, "unreg(%08x, %08x)" NL,
69 		commac->tx_chan_mask, commac->rx_chan_mask);
70 
71 	mal->tx_chan_mask &= ~commac->tx_chan_mask;
72 	mal->rx_chan_mask &= ~commac->rx_chan_mask;
73 	list_del_init(&commac->list);
74 	if (list_empty(&mal->list))
75 		napi_disable(&mal->napi);
76 
77 	spin_unlock_irqrestore(&mal->lock, flags);
78 }
79 
80 int mal_set_rcbs(struct mal_instance *mal, int channel, unsigned long size)
81 {
82 	BUG_ON(channel < 0 || channel >= mal->num_rx_chans ||
83 	       size > MAL_MAX_RX_SIZE);
84 
85 	MAL_DBG(mal, "set_rbcs(%d, %lu)" NL, channel, size);
86 
87 	if (size & 0xf) {
88 		printk(KERN_WARNING
89 		       "mal%d: incorrect RX size %lu for the channel %d\n",
90 		       mal->index, size, channel);
91 		return -EINVAL;
92 	}
93 
94 	set_mal_dcrn(mal, MAL_RCBS(channel), size >> 4);
95 	return 0;
96 }
97 
98 int mal_tx_bd_offset(struct mal_instance *mal, int channel)
99 {
100 	BUG_ON(channel < 0 || channel >= mal->num_tx_chans);
101 
102 	return channel * NUM_TX_BUFF;
103 }
104 
105 int mal_rx_bd_offset(struct mal_instance *mal, int channel)
106 {
107 	BUG_ON(channel < 0 || channel >= mal->num_rx_chans);
108 	return mal->num_tx_chans * NUM_TX_BUFF + channel * NUM_RX_BUFF;
109 }
110 
111 void mal_enable_tx_channel(struct mal_instance *mal, int channel)
112 {
113 	unsigned long flags;
114 
115 	spin_lock_irqsave(&mal->lock, flags);
116 
117 	MAL_DBG(mal, "enable_tx(%d)" NL, channel);
118 
119 	set_mal_dcrn(mal, MAL_TXCASR,
120 		     get_mal_dcrn(mal, MAL_TXCASR) | MAL_CHAN_MASK(channel));
121 
122 	spin_unlock_irqrestore(&mal->lock, flags);
123 }
124 
125 void mal_disable_tx_channel(struct mal_instance *mal, int channel)
126 {
127 	set_mal_dcrn(mal, MAL_TXCARR, MAL_CHAN_MASK(channel));
128 
129 	MAL_DBG(mal, "disable_tx(%d)" NL, channel);
130 }
131 
132 void mal_enable_rx_channel(struct mal_instance *mal, int channel)
133 {
134 	unsigned long flags;
135 
136 	/*
137 	 * On some 4xx PPC's (e.g. 460EX/GT), the rx channel is a multiple
138 	 * of 8, but enabling in MAL_RXCASR needs the divided by 8 value
139 	 * for the bitmask
140 	 */
141 	if (!(channel % 8))
142 		channel >>= 3;
143 
144 	spin_lock_irqsave(&mal->lock, flags);
145 
146 	MAL_DBG(mal, "enable_rx(%d)" NL, channel);
147 
148 	set_mal_dcrn(mal, MAL_RXCASR,
149 		     get_mal_dcrn(mal, MAL_RXCASR) | MAL_CHAN_MASK(channel));
150 
151 	spin_unlock_irqrestore(&mal->lock, flags);
152 }
153 
154 void mal_disable_rx_channel(struct mal_instance *mal, int channel)
155 {
156 	/*
157 	 * On some 4xx PPC's (e.g. 460EX/GT), the rx channel is a multiple
158 	 * of 8, but enabling in MAL_RXCASR needs the divided by 8 value
159 	 * for the bitmask
160 	 */
161 	if (!(channel % 8))
162 		channel >>= 3;
163 
164 	set_mal_dcrn(mal, MAL_RXCARR, MAL_CHAN_MASK(channel));
165 
166 	MAL_DBG(mal, "disable_rx(%d)" NL, channel);
167 }
168 
169 void mal_poll_add(struct mal_instance *mal, struct mal_commac *commac)
170 {
171 	unsigned long flags;
172 
173 	spin_lock_irqsave(&mal->lock, flags);
174 
175 	MAL_DBG(mal, "poll_add(%p)" NL, commac);
176 
177 	/* starts disabled */
178 	set_bit(MAL_COMMAC_POLL_DISABLED, &commac->flags);
179 
180 	list_add_tail(&commac->poll_list, &mal->poll_list);
181 
182 	spin_unlock_irqrestore(&mal->lock, flags);
183 }
184 
185 void mal_poll_del(struct mal_instance *mal, struct mal_commac *commac)
186 {
187 	unsigned long flags;
188 
189 	spin_lock_irqsave(&mal->lock, flags);
190 
191 	MAL_DBG(mal, "poll_del(%p)" NL, commac);
192 
193 	list_del(&commac->poll_list);
194 
195 	spin_unlock_irqrestore(&mal->lock, flags);
196 }
197 
198 /* synchronized by mal_poll() */
199 static inline void mal_enable_eob_irq(struct mal_instance *mal)
200 {
201 	MAL_DBG2(mal, "enable_irq" NL);
202 
203 	// XXX might want to cache MAL_CFG as the DCR read can be slooooow
204 	set_mal_dcrn(mal, MAL_CFG, get_mal_dcrn(mal, MAL_CFG) | MAL_CFG_EOPIE);
205 }
206 
207 /* synchronized by NAPI state */
208 static inline void mal_disable_eob_irq(struct mal_instance *mal)
209 {
210 	// XXX might want to cache MAL_CFG as the DCR read can be slooooow
211 	set_mal_dcrn(mal, MAL_CFG, get_mal_dcrn(mal, MAL_CFG) & ~MAL_CFG_EOPIE);
212 
213 	MAL_DBG2(mal, "disable_irq" NL);
214 }
215 
216 static irqreturn_t mal_serr(int irq, void *dev_instance)
217 {
218 	struct mal_instance *mal = dev_instance;
219 
220 	u32 esr = get_mal_dcrn(mal, MAL_ESR);
221 
222 	/* Clear the error status register */
223 	set_mal_dcrn(mal, MAL_ESR, esr);
224 
225 	MAL_DBG(mal, "SERR %08x" NL, esr);
226 
227 	if (esr & MAL_ESR_EVB) {
228 		if (esr & MAL_ESR_DE) {
229 			/* We ignore Descriptor error,
230 			 * TXDE or RXDE interrupt will be generated anyway.
231 			 */
232 			return IRQ_HANDLED;
233 		}
234 
235 		if (esr & MAL_ESR_PEIN) {
236 			/* PLB error, it's probably buggy hardware or
237 			 * incorrect physical address in BD (i.e. bug)
238 			 */
239 			if (net_ratelimit())
240 				printk(KERN_ERR
241 				       "mal%d: system error, "
242 				       "PLB (ESR = 0x%08x)\n",
243 				       mal->index, esr);
244 			return IRQ_HANDLED;
245 		}
246 
247 		/* OPB error, it's probably buggy hardware or incorrect
248 		 * EBC setup
249 		 */
250 		if (net_ratelimit())
251 			printk(KERN_ERR
252 			       "mal%d: system error, OPB (ESR = 0x%08x)\n",
253 			       mal->index, esr);
254 	}
255 	return IRQ_HANDLED;
256 }
257 
258 static inline void mal_schedule_poll(struct mal_instance *mal)
259 {
260 	if (likely(napi_schedule_prep(&mal->napi))) {
261 		MAL_DBG2(mal, "schedule_poll" NL);
262 		spin_lock(&mal->lock);
263 		mal_disable_eob_irq(mal);
264 		spin_unlock(&mal->lock);
265 		__napi_schedule(&mal->napi);
266 	} else
267 		MAL_DBG2(mal, "already in poll" NL);
268 }
269 
270 static irqreturn_t mal_txeob(int irq, void *dev_instance)
271 {
272 	struct mal_instance *mal = dev_instance;
273 
274 	u32 r = get_mal_dcrn(mal, MAL_TXEOBISR);
275 
276 	MAL_DBG2(mal, "txeob %08x" NL, r);
277 
278 	mal_schedule_poll(mal);
279 	set_mal_dcrn(mal, MAL_TXEOBISR, r);
280 
281 #ifdef CONFIG_PPC_DCR_NATIVE
282 	if (mal_has_feature(mal, MAL_FTR_CLEAR_ICINTSTAT))
283 		mtdcri(SDR0, DCRN_SDR_ICINTSTAT,
284 				(mfdcri(SDR0, DCRN_SDR_ICINTSTAT) | ICINTSTAT_ICTX));
285 #endif
286 
287 	return IRQ_HANDLED;
288 }
289 
290 static irqreturn_t mal_rxeob(int irq, void *dev_instance)
291 {
292 	struct mal_instance *mal = dev_instance;
293 
294 	u32 r = get_mal_dcrn(mal, MAL_RXEOBISR);
295 
296 	MAL_DBG2(mal, "rxeob %08x" NL, r);
297 
298 	mal_schedule_poll(mal);
299 	set_mal_dcrn(mal, MAL_RXEOBISR, r);
300 
301 #ifdef CONFIG_PPC_DCR_NATIVE
302 	if (mal_has_feature(mal, MAL_FTR_CLEAR_ICINTSTAT))
303 		mtdcri(SDR0, DCRN_SDR_ICINTSTAT,
304 				(mfdcri(SDR0, DCRN_SDR_ICINTSTAT) | ICINTSTAT_ICRX));
305 #endif
306 
307 	return IRQ_HANDLED;
308 }
309 
310 static irqreturn_t mal_txde(int irq, void *dev_instance)
311 {
312 	struct mal_instance *mal = dev_instance;
313 
314 	u32 deir = get_mal_dcrn(mal, MAL_TXDEIR);
315 	set_mal_dcrn(mal, MAL_TXDEIR, deir);
316 
317 	MAL_DBG(mal, "txde %08x" NL, deir);
318 
319 	if (net_ratelimit())
320 		printk(KERN_ERR
321 		       "mal%d: TX descriptor error (TXDEIR = 0x%08x)\n",
322 		       mal->index, deir);
323 
324 	return IRQ_HANDLED;
325 }
326 
327 static irqreturn_t mal_rxde(int irq, void *dev_instance)
328 {
329 	struct mal_instance *mal = dev_instance;
330 	struct list_head *l;
331 
332 	u32 deir = get_mal_dcrn(mal, MAL_RXDEIR);
333 
334 	MAL_DBG(mal, "rxde %08x" NL, deir);
335 
336 	list_for_each(l, &mal->list) {
337 		struct mal_commac *mc = list_entry(l, struct mal_commac, list);
338 		if (deir & mc->rx_chan_mask) {
339 			set_bit(MAL_COMMAC_RX_STOPPED, &mc->flags);
340 			mc->ops->rxde(mc->dev);
341 		}
342 	}
343 
344 	mal_schedule_poll(mal);
345 	set_mal_dcrn(mal, MAL_RXDEIR, deir);
346 
347 	return IRQ_HANDLED;
348 }
349 
350 static irqreturn_t mal_int(int irq, void *dev_instance)
351 {
352 	struct mal_instance *mal = dev_instance;
353 	u32 esr = get_mal_dcrn(mal, MAL_ESR);
354 
355 	if (esr & MAL_ESR_EVB) {
356 		/* descriptor error */
357 		if (esr & MAL_ESR_DE) {
358 			if (esr & MAL_ESR_CIDT)
359 				return mal_rxde(irq, dev_instance);
360 			else
361 				return mal_txde(irq, dev_instance);
362 		} else { /* SERR */
363 			return mal_serr(irq, dev_instance);
364 		}
365 	}
366 	return IRQ_HANDLED;
367 }
368 
369 void mal_poll_disable(struct mal_instance *mal, struct mal_commac *commac)
370 {
371 	/* Spinlock-type semantics: only one caller disable poll at a time */
372 	while (test_and_set_bit(MAL_COMMAC_POLL_DISABLED, &commac->flags))
373 		msleep(1);
374 
375 	/* Synchronize with the MAL NAPI poller */
376 	napi_synchronize(&mal->napi);
377 }
378 
379 void mal_poll_enable(struct mal_instance *mal, struct mal_commac *commac)
380 {
381 	smp_wmb();
382 	clear_bit(MAL_COMMAC_POLL_DISABLED, &commac->flags);
383 
384 	/* Feels better to trigger a poll here to catch up with events that
385 	 * may have happened on this channel while disabled. It will most
386 	 * probably be delayed until the next interrupt but that's mostly a
387 	 * non-issue in the context where this is called.
388 	 */
389 	napi_schedule(&mal->napi);
390 }
391 
392 static int mal_poll(struct napi_struct *napi, int budget)
393 {
394 	struct mal_instance *mal = container_of(napi, struct mal_instance, napi);
395 	struct list_head *l;
396 	int received = 0;
397 	unsigned long flags;
398 
399 	MAL_DBG2(mal, "poll(%d)" NL, budget);
400 
401 	/* Process TX skbs */
402 	list_for_each(l, &mal->poll_list) {
403 		struct mal_commac *mc =
404 			list_entry(l, struct mal_commac, poll_list);
405 		mc->ops->poll_tx(mc->dev);
406 	}
407 
408 	/* Process RX skbs.
409 	 *
410 	 * We _might_ need something more smart here to enforce polling
411 	 * fairness.
412 	 */
413 	list_for_each(l, &mal->poll_list) {
414 		struct mal_commac *mc =
415 			list_entry(l, struct mal_commac, poll_list);
416 		int n;
417 		if (unlikely(test_bit(MAL_COMMAC_POLL_DISABLED, &mc->flags)))
418 			continue;
419 		n = mc->ops->poll_rx(mc->dev, budget - received);
420 		if (n) {
421 			received += n;
422 			if (received >= budget)
423 				return budget;
424 		}
425 	}
426 
427 	if (napi_complete_done(napi, received)) {
428 		/* We need to disable IRQs to protect from RXDE IRQ here */
429 		spin_lock_irqsave(&mal->lock, flags);
430 		mal_enable_eob_irq(mal);
431 		spin_unlock_irqrestore(&mal->lock, flags);
432 	}
433 
434 	/* Check for "rotting" packet(s) */
435 	list_for_each(l, &mal->poll_list) {
436 		struct mal_commac *mc =
437 			list_entry(l, struct mal_commac, poll_list);
438 		if (unlikely(test_bit(MAL_COMMAC_POLL_DISABLED, &mc->flags)))
439 			continue;
440 		if (unlikely(mc->ops->peek_rx(mc->dev) ||
441 			     test_bit(MAL_COMMAC_RX_STOPPED, &mc->flags))) {
442 			MAL_DBG2(mal, "rotting packet" NL);
443 			if (!napi_reschedule(napi))
444 				goto more_work;
445 
446 			spin_lock_irqsave(&mal->lock, flags);
447 			mal_disable_eob_irq(mal);
448 			spin_unlock_irqrestore(&mal->lock, flags);
449 		}
450 		mc->ops->poll_tx(mc->dev);
451 	}
452 
453  more_work:
454 	MAL_DBG2(mal, "poll() %d <- %d" NL, budget, received);
455 	return received;
456 }
457 
458 static void mal_reset(struct mal_instance *mal)
459 {
460 	int n = 10;
461 
462 	MAL_DBG(mal, "reset" NL);
463 
464 	set_mal_dcrn(mal, MAL_CFG, MAL_CFG_SR);
465 
466 	/* Wait for reset to complete (1 system clock) */
467 	while ((get_mal_dcrn(mal, MAL_CFG) & MAL_CFG_SR) && n)
468 		--n;
469 
470 	if (unlikely(!n))
471 		printk(KERN_ERR "mal%d: reset timeout\n", mal->index);
472 }
473 
474 int mal_get_regs_len(struct mal_instance *mal)
475 {
476 	return sizeof(struct emac_ethtool_regs_subhdr) +
477 	    sizeof(struct mal_regs);
478 }
479 
480 void *mal_dump_regs(struct mal_instance *mal, void *buf)
481 {
482 	struct emac_ethtool_regs_subhdr *hdr = buf;
483 	struct mal_regs *regs = (struct mal_regs *)(hdr + 1);
484 	int i;
485 
486 	hdr->version = mal->version;
487 	hdr->index = mal->index;
488 
489 	regs->tx_count = mal->num_tx_chans;
490 	regs->rx_count = mal->num_rx_chans;
491 
492 	regs->cfg = get_mal_dcrn(mal, MAL_CFG);
493 	regs->esr = get_mal_dcrn(mal, MAL_ESR);
494 	regs->ier = get_mal_dcrn(mal, MAL_IER);
495 	regs->tx_casr = get_mal_dcrn(mal, MAL_TXCASR);
496 	regs->tx_carr = get_mal_dcrn(mal, MAL_TXCARR);
497 	regs->tx_eobisr = get_mal_dcrn(mal, MAL_TXEOBISR);
498 	regs->tx_deir = get_mal_dcrn(mal, MAL_TXDEIR);
499 	regs->rx_casr = get_mal_dcrn(mal, MAL_RXCASR);
500 	regs->rx_carr = get_mal_dcrn(mal, MAL_RXCARR);
501 	regs->rx_eobisr = get_mal_dcrn(mal, MAL_RXEOBISR);
502 	regs->rx_deir = get_mal_dcrn(mal, MAL_RXDEIR);
503 
504 	for (i = 0; i < regs->tx_count; ++i)
505 		regs->tx_ctpr[i] = get_mal_dcrn(mal, MAL_TXCTPR(i));
506 
507 	for (i = 0; i < regs->rx_count; ++i) {
508 		regs->rx_ctpr[i] = get_mal_dcrn(mal, MAL_RXCTPR(i));
509 		regs->rcbs[i] = get_mal_dcrn(mal, MAL_RCBS(i));
510 	}
511 	return regs + 1;
512 }
513 
514 static int mal_probe(struct platform_device *ofdev)
515 {
516 	struct mal_instance *mal;
517 	int err = 0, i, bd_size;
518 	int index = mal_count++;
519 	unsigned int dcr_base;
520 	const u32 *prop;
521 	u32 cfg;
522 	unsigned long irqflags;
523 	irq_handler_t hdlr_serr, hdlr_txde, hdlr_rxde;
524 
525 	mal = kzalloc(sizeof(struct mal_instance), GFP_KERNEL);
526 	if (!mal)
527 		return -ENOMEM;
528 
529 	mal->index = index;
530 	mal->ofdev = ofdev;
531 	mal->version = of_device_is_compatible(ofdev->dev.of_node, "ibm,mcmal2") ? 2 : 1;
532 
533 	MAL_DBG(mal, "probe" NL);
534 
535 	prop = of_get_property(ofdev->dev.of_node, "num-tx-chans", NULL);
536 	if (prop == NULL) {
537 		printk(KERN_ERR
538 		       "mal%d: can't find MAL num-tx-chans property!\n",
539 		       index);
540 		err = -ENODEV;
541 		goto fail;
542 	}
543 	mal->num_tx_chans = prop[0];
544 
545 	prop = of_get_property(ofdev->dev.of_node, "num-rx-chans", NULL);
546 	if (prop == NULL) {
547 		printk(KERN_ERR
548 		       "mal%d: can't find MAL num-rx-chans property!\n",
549 		       index);
550 		err = -ENODEV;
551 		goto fail;
552 	}
553 	mal->num_rx_chans = prop[0];
554 
555 	dcr_base = dcr_resource_start(ofdev->dev.of_node, 0);
556 	if (dcr_base == 0) {
557 		printk(KERN_ERR
558 		       "mal%d: can't find DCR resource!\n", index);
559 		err = -ENODEV;
560 		goto fail;
561 	}
562 	mal->dcr_host = dcr_map(ofdev->dev.of_node, dcr_base, 0x100);
563 	if (!DCR_MAP_OK(mal->dcr_host)) {
564 		printk(KERN_ERR
565 		       "mal%d: failed to map DCRs !\n", index);
566 		err = -ENODEV;
567 		goto fail;
568 	}
569 
570 	if (of_device_is_compatible(ofdev->dev.of_node, "ibm,mcmal-405ez")) {
571 #if defined(CONFIG_IBM_EMAC_MAL_CLR_ICINTSTAT) && \
572 		defined(CONFIG_IBM_EMAC_MAL_COMMON_ERR)
573 		mal->features |= (MAL_FTR_CLEAR_ICINTSTAT |
574 				MAL_FTR_COMMON_ERR_INT);
575 #else
576 		printk(KERN_ERR "%pOF: Support for 405EZ not enabled!\n",
577 				ofdev->dev.of_node);
578 		err = -ENODEV;
579 		goto fail;
580 #endif
581 	}
582 
583 	mal->txeob_irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
584 	mal->rxeob_irq = irq_of_parse_and_map(ofdev->dev.of_node, 1);
585 	mal->serr_irq = irq_of_parse_and_map(ofdev->dev.of_node, 2);
586 
587 	if (mal_has_feature(mal, MAL_FTR_COMMON_ERR_INT)) {
588 		mal->txde_irq = mal->rxde_irq = mal->serr_irq;
589 	} else {
590 		mal->txde_irq = irq_of_parse_and_map(ofdev->dev.of_node, 3);
591 		mal->rxde_irq = irq_of_parse_and_map(ofdev->dev.of_node, 4);
592 	}
593 
594 	if (!mal->txeob_irq || !mal->rxeob_irq || !mal->serr_irq ||
595 	    !mal->txde_irq  || !mal->rxde_irq) {
596 		printk(KERN_ERR
597 		       "mal%d: failed to map interrupts !\n", index);
598 		err = -ENODEV;
599 		goto fail_unmap;
600 	}
601 
602 	INIT_LIST_HEAD(&mal->poll_list);
603 	INIT_LIST_HEAD(&mal->list);
604 	spin_lock_init(&mal->lock);
605 
606 	init_dummy_netdev(&mal->dummy_dev);
607 
608 	netif_napi_add(&mal->dummy_dev, &mal->napi, mal_poll,
609 		       CONFIG_IBM_EMAC_POLL_WEIGHT);
610 
611 	/* Load power-on reset defaults */
612 	mal_reset(mal);
613 
614 	/* Set the MAL configuration register */
615 	cfg = (mal->version == 2) ? MAL2_CFG_DEFAULT : MAL1_CFG_DEFAULT;
616 	cfg |= MAL_CFG_PLBB | MAL_CFG_OPBBL | MAL_CFG_LEA;
617 
618 	/* Current Axon is not happy with priority being non-0, it can
619 	 * deadlock, fix it up here
620 	 */
621 	if (of_device_is_compatible(ofdev->dev.of_node, "ibm,mcmal-axon"))
622 		cfg &= ~(MAL2_CFG_RPP_10 | MAL2_CFG_WPP_10);
623 
624 	/* Apply configuration */
625 	set_mal_dcrn(mal, MAL_CFG, cfg);
626 
627 	/* Allocate space for BD rings */
628 	BUG_ON(mal->num_tx_chans <= 0 || mal->num_tx_chans > 32);
629 	BUG_ON(mal->num_rx_chans <= 0 || mal->num_rx_chans > 32);
630 
631 	bd_size = sizeof(struct mal_descriptor) *
632 		(NUM_TX_BUFF * mal->num_tx_chans +
633 		 NUM_RX_BUFF * mal->num_rx_chans);
634 	mal->bd_virt = dma_alloc_coherent(&ofdev->dev, bd_size, &mal->bd_dma,
635 					  GFP_KERNEL);
636 	if (mal->bd_virt == NULL) {
637 		err = -ENOMEM;
638 		goto fail_unmap;
639 	}
640 
641 	for (i = 0; i < mal->num_tx_chans; ++i)
642 		set_mal_dcrn(mal, MAL_TXCTPR(i), mal->bd_dma +
643 			     sizeof(struct mal_descriptor) *
644 			     mal_tx_bd_offset(mal, i));
645 
646 	for (i = 0; i < mal->num_rx_chans; ++i)
647 		set_mal_dcrn(mal, MAL_RXCTPR(i), mal->bd_dma +
648 			     sizeof(struct mal_descriptor) *
649 			     mal_rx_bd_offset(mal, i));
650 
651 	if (mal_has_feature(mal, MAL_FTR_COMMON_ERR_INT)) {
652 		irqflags = IRQF_SHARED;
653 		hdlr_serr = hdlr_txde = hdlr_rxde = mal_int;
654 	} else {
655 		irqflags = 0;
656 		hdlr_serr = mal_serr;
657 		hdlr_txde = mal_txde;
658 		hdlr_rxde = mal_rxde;
659 	}
660 
661 	err = request_irq(mal->serr_irq, hdlr_serr, irqflags, "MAL SERR", mal);
662 	if (err)
663 		goto fail2;
664 	err = request_irq(mal->txde_irq, hdlr_txde, irqflags, "MAL TX DE", mal);
665 	if (err)
666 		goto fail3;
667 	err = request_irq(mal->txeob_irq, mal_txeob, 0, "MAL TX EOB", mal);
668 	if (err)
669 		goto fail4;
670 	err = request_irq(mal->rxde_irq, hdlr_rxde, irqflags, "MAL RX DE", mal);
671 	if (err)
672 		goto fail5;
673 	err = request_irq(mal->rxeob_irq, mal_rxeob, 0, "MAL RX EOB", mal);
674 	if (err)
675 		goto fail6;
676 
677 	/* Enable all MAL SERR interrupt sources */
678 	set_mal_dcrn(mal, MAL_IER, MAL_IER_EVENTS);
679 
680 	/* Enable EOB interrupt */
681 	mal_enable_eob_irq(mal);
682 
683 	printk(KERN_INFO
684 	       "MAL v%d %pOF, %d TX channels, %d RX channels\n",
685 	       mal->version, ofdev->dev.of_node,
686 	       mal->num_tx_chans, mal->num_rx_chans);
687 
688 	/* Advertise this instance to the rest of the world */
689 	wmb();
690 	platform_set_drvdata(ofdev, mal);
691 
692 	return 0;
693 
694  fail6:
695 	free_irq(mal->rxde_irq, mal);
696  fail5:
697 	free_irq(mal->txeob_irq, mal);
698  fail4:
699 	free_irq(mal->txde_irq, mal);
700  fail3:
701 	free_irq(mal->serr_irq, mal);
702  fail2:
703 	dma_free_coherent(&ofdev->dev, bd_size, mal->bd_virt, mal->bd_dma);
704  fail_unmap:
705 	dcr_unmap(mal->dcr_host, 0x100);
706  fail:
707 	kfree(mal);
708 
709 	return err;
710 }
711 
712 static int mal_remove(struct platform_device *ofdev)
713 {
714 	struct mal_instance *mal = platform_get_drvdata(ofdev);
715 
716 	MAL_DBG(mal, "remove" NL);
717 
718 	/* Synchronize with scheduled polling */
719 	napi_disable(&mal->napi);
720 
721 	if (!list_empty(&mal->list))
722 		/* This is *very* bad */
723 		WARN(1, KERN_EMERG
724 		       "mal%d: commac list is not empty on remove!\n",
725 		       mal->index);
726 
727 	free_irq(mal->serr_irq, mal);
728 	free_irq(mal->txde_irq, mal);
729 	free_irq(mal->txeob_irq, mal);
730 	free_irq(mal->rxde_irq, mal);
731 	free_irq(mal->rxeob_irq, mal);
732 
733 	mal_reset(mal);
734 
735 	dma_free_coherent(&ofdev->dev,
736 			  sizeof(struct mal_descriptor) *
737 			  (NUM_TX_BUFF * mal->num_tx_chans +
738 			   NUM_RX_BUFF * mal->num_rx_chans), mal->bd_virt,
739 			  mal->bd_dma);
740 	kfree(mal);
741 
742 	return 0;
743 }
744 
745 static const struct of_device_id mal_platform_match[] =
746 {
747 	{
748 		.compatible	= "ibm,mcmal",
749 	},
750 	{
751 		.compatible	= "ibm,mcmal2",
752 	},
753 	/* Backward compat */
754 	{
755 		.type		= "mcmal-dma",
756 		.compatible	= "ibm,mcmal",
757 	},
758 	{
759 		.type		= "mcmal-dma",
760 		.compatible	= "ibm,mcmal2",
761 	},
762 	{},
763 };
764 
765 static struct platform_driver mal_of_driver = {
766 	.driver = {
767 		.name = "mcmal",
768 		.of_match_table = mal_platform_match,
769 	},
770 	.probe = mal_probe,
771 	.remove = mal_remove,
772 };
773 
774 int __init mal_init(void)
775 {
776 	return platform_driver_register(&mal_of_driver);
777 }
778 
779 void mal_exit(void)
780 {
781 	platform_driver_unregister(&mal_of_driver);
782 }
783