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1/*
2 * Intel I/OAT DMA Linux driver
3 * Copyright(c) 2004 - 2009 Intel Corporation.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * The full GNU General Public License is included in this distribution in
19 * the file called "COPYING".
20 *
21 */
22
23/*
24 * This driver supports an Intel I/OAT DMA engine (versions >= 2), which
25 * does asynchronous data movement and checksumming operations.
26 */
27
28#include <linux/init.h>
29#include <linux/module.h>
30#include <linux/slab.h>
31#include <linux/pci.h>
32#include <linux/interrupt.h>
33#include <linux/dmaengine.h>
34#include <linux/delay.h>
35#include <linux/dma-mapping.h>
36#include <linux/workqueue.h>
37#include <linux/i7300_idle.h>
38#include "dma.h"
39#include "dma_v2.h"
40#include "registers.h"
41#include "hw.h"
42
43int ioat_ring_alloc_order = 8;
44module_param(ioat_ring_alloc_order, int, 0644);
45MODULE_PARM_DESC(ioat_ring_alloc_order,
46		 "ioat2+: allocate 2^n descriptors per channel"
47		 " (default: 8 max: 16)");
48static int ioat_ring_max_alloc_order = IOAT_MAX_ORDER;
49module_param(ioat_ring_max_alloc_order, int, 0644);
50MODULE_PARM_DESC(ioat_ring_max_alloc_order,
51		 "ioat2+: upper limit for ring size (default: 16)");
52
53void __ioat2_issue_pending(struct ioat2_dma_chan *ioat)
54{
55	struct ioat_chan_common *chan = &ioat->base;
56
57	ioat->dmacount += ioat2_ring_pending(ioat);
58	ioat->issued = ioat->head;
59	writew(ioat->dmacount, chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
60	dev_dbg(to_dev(chan),
61		"%s: head: %#x tail: %#x issued: %#x count: %#x\n",
62		__func__, ioat->head, ioat->tail, ioat->issued, ioat->dmacount);
63}
64
65void ioat2_issue_pending(struct dma_chan *c)
66{
67	struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
68
69	if (ioat2_ring_pending(ioat)) {
70		spin_lock_bh(&ioat->prep_lock);
71		__ioat2_issue_pending(ioat);
72		spin_unlock_bh(&ioat->prep_lock);
73	}
74}
75
76/**
77 * ioat2_update_pending - log pending descriptors
78 * @ioat: ioat2+ channel
79 *
80 * Check if the number of unsubmitted descriptors has exceeded the
81 * watermark.  Called with prep_lock held
82 */
83static void ioat2_update_pending(struct ioat2_dma_chan *ioat)
84{
85	if (ioat2_ring_pending(ioat) > ioat_pending_level)
86		__ioat2_issue_pending(ioat);
87}
88
89static void __ioat2_start_null_desc(struct ioat2_dma_chan *ioat)
90{
91	struct ioat_ring_ent *desc;
92	struct ioat_dma_descriptor *hw;
93
94	if (ioat2_ring_space(ioat) < 1) {
95		dev_err(to_dev(&ioat->base),
96			"Unable to start null desc - ring full\n");
97		return;
98	}
99
100	dev_dbg(to_dev(&ioat->base), "%s: head: %#x tail: %#x issued: %#x\n",
101		__func__, ioat->head, ioat->tail, ioat->issued);
102	desc = ioat2_get_ring_ent(ioat, ioat->head);
103
104	hw = desc->hw;
105	hw->ctl = 0;
106	hw->ctl_f.null = 1;
107	hw->ctl_f.int_en = 1;
108	hw->ctl_f.compl_write = 1;
109	/* set size to non-zero value (channel returns error when size is 0) */
110	hw->size = NULL_DESC_BUFFER_SIZE;
111	hw->src_addr = 0;
112	hw->dst_addr = 0;
113	async_tx_ack(&desc->txd);
114	ioat2_set_chainaddr(ioat, desc->txd.phys);
115	dump_desc_dbg(ioat, desc);
116	wmb();
117	ioat->head += 1;
118	__ioat2_issue_pending(ioat);
119}
120
121static void ioat2_start_null_desc(struct ioat2_dma_chan *ioat)
122{
123	spin_lock_bh(&ioat->prep_lock);
124	__ioat2_start_null_desc(ioat);
125	spin_unlock_bh(&ioat->prep_lock);
126}
127
128static void __cleanup(struct ioat2_dma_chan *ioat, unsigned long phys_complete)
129{
130	struct ioat_chan_common *chan = &ioat->base;
131	struct dma_async_tx_descriptor *tx;
132	struct ioat_ring_ent *desc;
133	bool seen_current = false;
134	u16 active;
135	int idx = ioat->tail, i;
136
137	dev_dbg(to_dev(chan), "%s: head: %#x tail: %#x issued: %#x\n",
138		__func__, ioat->head, ioat->tail, ioat->issued);
139
140	active = ioat2_ring_active(ioat);
141	for (i = 0; i < active && !seen_current; i++) {
142		smp_read_barrier_depends();
143		prefetch(ioat2_get_ring_ent(ioat, idx + i + 1));
144		desc = ioat2_get_ring_ent(ioat, idx + i);
145		tx = &desc->txd;
146		dump_desc_dbg(ioat, desc);
147		if (tx->cookie) {
148			ioat_dma_unmap(chan, tx->flags, desc->len, desc->hw);
149			chan->completed_cookie = tx->cookie;
150			tx->cookie = 0;
151			if (tx->callback) {
152				tx->callback(tx->callback_param);
153				tx->callback = NULL;
154			}
155		}
156
157		if (tx->phys == phys_complete)
158			seen_current = true;
159	}
160	smp_mb(); /* finish all descriptor reads before incrementing tail */
161	ioat->tail = idx + i;
162	BUG_ON(active && !seen_current); /* no active descs have written a completion? */
163
164	chan->last_completion = phys_complete;
165	if (active - i == 0) {
166		dev_dbg(to_dev(chan), "%s: cancel completion timeout\n",
167			__func__);
168		clear_bit(IOAT_COMPLETION_PENDING, &chan->state);
169		mod_timer(&chan->timer, jiffies + IDLE_TIMEOUT);
170	}
171}
172
173/**
174 * ioat2_cleanup - clean finished descriptors (advance tail pointer)
175 * @chan: ioat channel to be cleaned up
176 */
177static void ioat2_cleanup(struct ioat2_dma_chan *ioat)
178{
179	struct ioat_chan_common *chan = &ioat->base;
180	unsigned long phys_complete;
181
182	spin_lock_bh(&chan->cleanup_lock);
183	if (ioat_cleanup_preamble(chan, &phys_complete))
184		__cleanup(ioat, phys_complete);
185	spin_unlock_bh(&chan->cleanup_lock);
186}
187
188void ioat2_cleanup_event(unsigned long data)
189{
190	struct ioat2_dma_chan *ioat = to_ioat2_chan((void *) data);
191
192	ioat2_cleanup(ioat);
193	writew(IOAT_CHANCTRL_RUN, ioat->base.reg_base + IOAT_CHANCTRL_OFFSET);
194}
195
196void __ioat2_restart_chan(struct ioat2_dma_chan *ioat)
197{
198	struct ioat_chan_common *chan = &ioat->base;
199
200	/* set the tail to be re-issued */
201	ioat->issued = ioat->tail;
202	ioat->dmacount = 0;
203	set_bit(IOAT_COMPLETION_PENDING, &chan->state);
204	mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
205
206	dev_dbg(to_dev(chan),
207		"%s: head: %#x tail: %#x issued: %#x count: %#x\n",
208		__func__, ioat->head, ioat->tail, ioat->issued, ioat->dmacount);
209
210	if (ioat2_ring_pending(ioat)) {
211		struct ioat_ring_ent *desc;
212
213		desc = ioat2_get_ring_ent(ioat, ioat->tail);
214		ioat2_set_chainaddr(ioat, desc->txd.phys);
215		__ioat2_issue_pending(ioat);
216	} else
217		__ioat2_start_null_desc(ioat);
218}
219
220int ioat2_quiesce(struct ioat_chan_common *chan, unsigned long tmo)
221{
222	unsigned long end = jiffies + tmo;
223	int err = 0;
224	u32 status;
225
226	status = ioat_chansts(chan);
227	if (is_ioat_active(status) || is_ioat_idle(status))
228		ioat_suspend(chan);
229	while (is_ioat_active(status) || is_ioat_idle(status)) {
230		if (tmo && time_after(jiffies, end)) {
231			err = -ETIMEDOUT;
232			break;
233		}
234		status = ioat_chansts(chan);
235		cpu_relax();
236	}
237
238	return err;
239}
240
241int ioat2_reset_sync(struct ioat_chan_common *chan, unsigned long tmo)
242{
243	unsigned long end = jiffies + tmo;
244	int err = 0;
245
246	ioat_reset(chan);
247	while (ioat_reset_pending(chan)) {
248		if (end && time_after(jiffies, end)) {
249			err = -ETIMEDOUT;
250			break;
251		}
252		cpu_relax();
253	}
254
255	return err;
256}
257
258static void ioat2_restart_channel(struct ioat2_dma_chan *ioat)
259{
260	struct ioat_chan_common *chan = &ioat->base;
261	unsigned long phys_complete;
262
263	ioat2_quiesce(chan, 0);
264	if (ioat_cleanup_preamble(chan, &phys_complete))
265		__cleanup(ioat, phys_complete);
266
267	__ioat2_restart_chan(ioat);
268}
269
270void ioat2_timer_event(unsigned long data)
271{
272	struct ioat2_dma_chan *ioat = to_ioat2_chan((void *) data);
273	struct ioat_chan_common *chan = &ioat->base;
274
275	if (test_bit(IOAT_COMPLETION_PENDING, &chan->state)) {
276		unsigned long phys_complete;
277		u64 status;
278
279		status = ioat_chansts(chan);
280
281		/* when halted due to errors check for channel
282		 * programming errors before advancing the completion state
283		 */
284		if (is_ioat_halted(status)) {
285			u32 chanerr;
286
287			chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
288			dev_err(to_dev(chan), "%s: Channel halted (%x)\n",
289				__func__, chanerr);
290			if (test_bit(IOAT_RUN, &chan->state))
291				BUG_ON(is_ioat_bug(chanerr));
292			else /* we never got off the ground */
293				return;
294		}
295
296		/* if we haven't made progress and we have already
297		 * acknowledged a pending completion once, then be more
298		 * forceful with a restart
299		 */
300		spin_lock_bh(&chan->cleanup_lock);
301		if (ioat_cleanup_preamble(chan, &phys_complete)) {
302			__cleanup(ioat, phys_complete);
303		} else if (test_bit(IOAT_COMPLETION_ACK, &chan->state)) {
304			spin_lock_bh(&ioat->prep_lock);
305			ioat2_restart_channel(ioat);
306			spin_unlock_bh(&ioat->prep_lock);
307		} else {
308			set_bit(IOAT_COMPLETION_ACK, &chan->state);
309			mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
310		}
311		spin_unlock_bh(&chan->cleanup_lock);
312	} else {
313		u16 active;
314
315		/* if the ring is idle, empty, and oversized try to step
316		 * down the size
317		 */
318		spin_lock_bh(&chan->cleanup_lock);
319		spin_lock_bh(&ioat->prep_lock);
320		active = ioat2_ring_active(ioat);
321		if (active == 0 && ioat->alloc_order > ioat_get_alloc_order())
322			reshape_ring(ioat, ioat->alloc_order-1);
323		spin_unlock_bh(&ioat->prep_lock);
324		spin_unlock_bh(&chan->cleanup_lock);
325
326		/* keep shrinking until we get back to our minimum
327		 * default size
328		 */
329		if (ioat->alloc_order > ioat_get_alloc_order())
330			mod_timer(&chan->timer, jiffies + IDLE_TIMEOUT);
331	}
332}
333
334static int ioat2_reset_hw(struct ioat_chan_common *chan)
335{
336	/* throw away whatever the channel was doing and get it initialized */
337	u32 chanerr;
338
339	ioat2_quiesce(chan, msecs_to_jiffies(100));
340
341	chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
342	writel(chanerr, chan->reg_base + IOAT_CHANERR_OFFSET);
343
344	return ioat2_reset_sync(chan, msecs_to_jiffies(200));
345}
346
347/**
348 * ioat2_enumerate_channels - find and initialize the device's channels
349 * @device: the device to be enumerated
350 */
351int ioat2_enumerate_channels(struct ioatdma_device *device)
352{
353	struct ioat2_dma_chan *ioat;
354	struct device *dev = &device->pdev->dev;
355	struct dma_device *dma = &device->common;
356	u8 xfercap_log;
357	int i;
358
359	INIT_LIST_HEAD(&dma->channels);
360	dma->chancnt = readb(device->reg_base + IOAT_CHANCNT_OFFSET);
361	dma->chancnt &= 0x1f; /* bits [4:0] valid */
362	if (dma->chancnt > ARRAY_SIZE(device->idx)) {
363		dev_warn(dev, "(%d) exceeds max supported channels (%zu)\n",
364			 dma->chancnt, ARRAY_SIZE(device->idx));
365		dma->chancnt = ARRAY_SIZE(device->idx);
366	}
367	xfercap_log = readb(device->reg_base + IOAT_XFERCAP_OFFSET);
368	xfercap_log &= 0x1f; /* bits [4:0] valid */
369	if (xfercap_log == 0)
370		return 0;
371	dev_dbg(dev, "%s: xfercap = %d\n", __func__, 1 << xfercap_log);
372
373#ifdef CONFIG_I7300_IDLE_IOAT_CHANNEL
374	if (i7300_idle_platform_probe(NULL, NULL, 1) == 0)
375		dma->chancnt--;
376#endif
377	for (i = 0; i < dma->chancnt; i++) {
378		ioat = devm_kzalloc(dev, sizeof(*ioat), GFP_KERNEL);
379		if (!ioat)
380			break;
381
382		ioat_init_channel(device, &ioat->base, i);
383		ioat->xfercap_log = xfercap_log;
384		spin_lock_init(&ioat->prep_lock);
385		if (device->reset_hw(&ioat->base)) {
386			i = 0;
387			break;
388		}
389	}
390	dma->chancnt = i;
391	return i;
392}
393
394static dma_cookie_t ioat2_tx_submit_unlock(struct dma_async_tx_descriptor *tx)
395{
396	struct dma_chan *c = tx->chan;
397	struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
398	struct ioat_chan_common *chan = &ioat->base;
399	dma_cookie_t cookie = c->cookie;
400
401	cookie++;
402	if (cookie < 0)
403		cookie = 1;
404	tx->cookie = cookie;
405	c->cookie = cookie;
406	dev_dbg(to_dev(&ioat->base), "%s: cookie: %d\n", __func__, cookie);
407
408	if (!test_and_set_bit(IOAT_COMPLETION_PENDING, &chan->state))
409		mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
410
411	/* make descriptor updates visible before advancing ioat->head,
412	 * this is purposefully not smp_wmb() since we are also
413	 * publishing the descriptor updates to a dma device
414	 */
415	wmb();
416
417	ioat->head += ioat->produce;
418
419	ioat2_update_pending(ioat);
420	spin_unlock_bh(&ioat->prep_lock);
421
422	return cookie;
423}
424
425static struct ioat_ring_ent *ioat2_alloc_ring_ent(struct dma_chan *chan, gfp_t flags)
426{
427	struct ioat_dma_descriptor *hw;
428	struct ioat_ring_ent *desc;
429	struct ioatdma_device *dma;
430	dma_addr_t phys;
431
432	dma = to_ioatdma_device(chan->device);
433	hw = pci_pool_alloc(dma->dma_pool, flags, &phys);
434	if (!hw)
435		return NULL;
436	memset(hw, 0, sizeof(*hw));
437
438	desc = kmem_cache_alloc(ioat2_cache, flags);
439	if (!desc) {
440		pci_pool_free(dma->dma_pool, hw, phys);
441		return NULL;
442	}
443	memset(desc, 0, sizeof(*desc));
444
445	dma_async_tx_descriptor_init(&desc->txd, chan);
446	desc->txd.tx_submit = ioat2_tx_submit_unlock;
447	desc->hw = hw;
448	desc->txd.phys = phys;
449	return desc;
450}
451
452static void ioat2_free_ring_ent(struct ioat_ring_ent *desc, struct dma_chan *chan)
453{
454	struct ioatdma_device *dma;
455
456	dma = to_ioatdma_device(chan->device);
457	pci_pool_free(dma->dma_pool, desc->hw, desc->txd.phys);
458	kmem_cache_free(ioat2_cache, desc);
459}
460
461static struct ioat_ring_ent **ioat2_alloc_ring(struct dma_chan *c, int order, gfp_t flags)
462{
463	struct ioat_ring_ent **ring;
464	int descs = 1 << order;
465	int i;
466
467	if (order > ioat_get_max_alloc_order())
468		return NULL;
469
470	/* allocate the array to hold the software ring */
471	ring = kcalloc(descs, sizeof(*ring), flags);
472	if (!ring)
473		return NULL;
474	for (i = 0; i < descs; i++) {
475		ring[i] = ioat2_alloc_ring_ent(c, flags);
476		if (!ring[i]) {
477			while (i--)
478				ioat2_free_ring_ent(ring[i], c);
479			kfree(ring);
480			return NULL;
481		}
482		set_desc_id(ring[i], i);
483	}
484
485	/* link descs */
486	for (i = 0; i < descs-1; i++) {
487		struct ioat_ring_ent *next = ring[i+1];
488		struct ioat_dma_descriptor *hw = ring[i]->hw;
489
490		hw->next = next->txd.phys;
491	}
492	ring[i]->hw->next = ring[0]->txd.phys;
493
494	return ring;
495}
496
497void ioat2_free_chan_resources(struct dma_chan *c);
498
499/* ioat2_alloc_chan_resources - allocate/initialize ioat2 descriptor ring
500 * @chan: channel to be initialized
501 */
502int ioat2_alloc_chan_resources(struct dma_chan *c)
503{
504	struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
505	struct ioat_chan_common *chan = &ioat->base;
506	struct ioat_ring_ent **ring;
507	u64 status;
508	int order;
509
510	/* have we already been set up? */
511	if (ioat->ring)
512		return 1 << ioat->alloc_order;
513
514	/* Setup register to interrupt and write completion status on error */
515	writew(IOAT_CHANCTRL_RUN, chan->reg_base + IOAT_CHANCTRL_OFFSET);
516
517	/* allocate a completion writeback area */
518	/* doing 2 32bit writes to mmio since 1 64b write doesn't work */
519	chan->completion = pci_pool_alloc(chan->device->completion_pool,
520					  GFP_KERNEL, &chan->completion_dma);
521	if (!chan->completion)
522		return -ENOMEM;
523
524	memset(chan->completion, 0, sizeof(*chan->completion));
525	writel(((u64) chan->completion_dma) & 0x00000000FFFFFFFF,
526	       chan->reg_base + IOAT_CHANCMP_OFFSET_LOW);
527	writel(((u64) chan->completion_dma) >> 32,
528	       chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH);
529
530	order = ioat_get_alloc_order();
531	ring = ioat2_alloc_ring(c, order, GFP_KERNEL);
532	if (!ring)
533		return -ENOMEM;
534
535	spin_lock_bh(&chan->cleanup_lock);
536	spin_lock_bh(&ioat->prep_lock);
537	ioat->ring = ring;
538	ioat->head = 0;
539	ioat->issued = 0;
540	ioat->tail = 0;
541	ioat->alloc_order = order;
542	spin_unlock_bh(&ioat->prep_lock);
543	spin_unlock_bh(&chan->cleanup_lock);
544
545	tasklet_enable(&chan->cleanup_task);
546	ioat2_start_null_desc(ioat);
547
548	/* check that we got off the ground */
549	udelay(5);
550	status = ioat_chansts(chan);
551	if (is_ioat_active(status) || is_ioat_idle(status)) {
552		set_bit(IOAT_RUN, &chan->state);
553		return 1 << ioat->alloc_order;
554	} else {
555		u32 chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
556
557		dev_WARN(to_dev(chan),
558			"failed to start channel chanerr: %#x\n", chanerr);
559		ioat2_free_chan_resources(c);
560		return -EFAULT;
561	}
562}
563
564bool reshape_ring(struct ioat2_dma_chan *ioat, int order)
565{
566	/* reshape differs from normal ring allocation in that we want
567	 * to allocate a new software ring while only
568	 * extending/truncating the hardware ring
569	 */
570	struct ioat_chan_common *chan = &ioat->base;
571	struct dma_chan *c = &chan->common;
572	const u16 curr_size = ioat2_ring_size(ioat);
573	const u16 active = ioat2_ring_active(ioat);
574	const u16 new_size = 1 << order;
575	struct ioat_ring_ent **ring;
576	u16 i;
577
578	if (order > ioat_get_max_alloc_order())
579		return false;
580
581	/* double check that we have at least 1 free descriptor */
582	if (active == curr_size)
583		return false;
584
585	/* when shrinking, verify that we can hold the current active
586	 * set in the new ring
587	 */
588	if (active >= new_size)
589		return false;
590
591	/* allocate the array to hold the software ring */
592	ring = kcalloc(new_size, sizeof(*ring), GFP_NOWAIT);
593	if (!ring)
594		return false;
595
596	/* allocate/trim descriptors as needed */
597	if (new_size > curr_size) {
598		/* copy current descriptors to the new ring */
599		for (i = 0; i < curr_size; i++) {
600			u16 curr_idx = (ioat->tail+i) & (curr_size-1);
601			u16 new_idx = (ioat->tail+i) & (new_size-1);
602
603			ring[new_idx] = ioat->ring[curr_idx];
604			set_desc_id(ring[new_idx], new_idx);
605		}
606
607		/* add new descriptors to the ring */
608		for (i = curr_size; i < new_size; i++) {
609			u16 new_idx = (ioat->tail+i) & (new_size-1);
610
611			ring[new_idx] = ioat2_alloc_ring_ent(c, GFP_NOWAIT);
612			if (!ring[new_idx]) {
613				while (i--) {
614					u16 new_idx = (ioat->tail+i) & (new_size-1);
615
616					ioat2_free_ring_ent(ring[new_idx], c);
617				}
618				kfree(ring);
619				return false;
620			}
621			set_desc_id(ring[new_idx], new_idx);
622		}
623
624		/* hw link new descriptors */
625		for (i = curr_size-1; i < new_size; i++) {
626			u16 new_idx = (ioat->tail+i) & (new_size-1);
627			struct ioat_ring_ent *next = ring[(new_idx+1) & (new_size-1)];
628			struct ioat_dma_descriptor *hw = ring[new_idx]->hw;
629
630			hw->next = next->txd.phys;
631		}
632	} else {
633		struct ioat_dma_descriptor *hw;
634		struct ioat_ring_ent *next;
635
636		/* copy current descriptors to the new ring, dropping the
637		 * removed descriptors
638		 */
639		for (i = 0; i < new_size; i++) {
640			u16 curr_idx = (ioat->tail+i) & (curr_size-1);
641			u16 new_idx = (ioat->tail+i) & (new_size-1);
642
643			ring[new_idx] = ioat->ring[curr_idx];
644			set_desc_id(ring[new_idx], new_idx);
645		}
646
647		/* free deleted descriptors */
648		for (i = new_size; i < curr_size; i++) {
649			struct ioat_ring_ent *ent;
650
651			ent = ioat2_get_ring_ent(ioat, ioat->tail+i);
652			ioat2_free_ring_ent(ent, c);
653		}
654
655		/* fix up hardware ring */
656		hw = ring[(ioat->tail+new_size-1) & (new_size-1)]->hw;
657		next = ring[(ioat->tail+new_size) & (new_size-1)];
658		hw->next = next->txd.phys;
659	}
660
661	dev_dbg(to_dev(chan), "%s: allocated %d descriptors\n",
662		__func__, new_size);
663
664	kfree(ioat->ring);
665	ioat->ring = ring;
666	ioat->alloc_order = order;
667
668	return true;
669}
670
671/**
672 * ioat2_check_space_lock - verify space and grab ring producer lock
673 * @ioat: ioat2,3 channel (ring) to operate on
674 * @num_descs: allocation length
675 */
676int ioat2_check_space_lock(struct ioat2_dma_chan *ioat, int num_descs)
677{
678	struct ioat_chan_common *chan = &ioat->base;
679	bool retry;
680
681 retry:
682	spin_lock_bh(&ioat->prep_lock);
683	/* never allow the last descriptor to be consumed, we need at
684	 * least one free at all times to allow for on-the-fly ring
685	 * resizing.
686	 */
687	if (likely(ioat2_ring_space(ioat) > num_descs)) {
688		dev_dbg(to_dev(chan), "%s: num_descs: %d (%x:%x:%x)\n",
689			__func__, num_descs, ioat->head, ioat->tail, ioat->issued);
690		ioat->produce = num_descs;
691		return 0;  /* with ioat->prep_lock held */
692	}
693	retry = test_and_set_bit(IOAT_RESHAPE_PENDING, &chan->state);
694	spin_unlock_bh(&ioat->prep_lock);
695
696	/* is another cpu already trying to expand the ring? */
697	if (retry)
698		goto retry;
699
700	spin_lock_bh(&chan->cleanup_lock);
701	spin_lock_bh(&ioat->prep_lock);
702	retry = reshape_ring(ioat, ioat->alloc_order + 1);
703	clear_bit(IOAT_RESHAPE_PENDING, &chan->state);
704	spin_unlock_bh(&ioat->prep_lock);
705	spin_unlock_bh(&chan->cleanup_lock);
706
707	/* if we were able to expand the ring retry the allocation */
708	if (retry)
709		goto retry;
710
711	if (printk_ratelimit())
712		dev_dbg(to_dev(chan), "%s: ring full! num_descs: %d (%x:%x:%x)\n",
713			__func__, num_descs, ioat->head, ioat->tail, ioat->issued);
714
715	/* progress reclaim in the allocation failure case we may be
716	 * called under bh_disabled so we need to trigger the timer
717	 * event directly
718	 */
719	if (jiffies > chan->timer.expires && timer_pending(&chan->timer)) {
720		struct ioatdma_device *device = chan->device;
721
722		mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
723		device->timer_fn((unsigned long) &chan->common);
724	}
725
726	return -ENOMEM;
727}
728
729struct dma_async_tx_descriptor *
730ioat2_dma_prep_memcpy_lock(struct dma_chan *c, dma_addr_t dma_dest,
731			   dma_addr_t dma_src, size_t len, unsigned long flags)
732{
733	struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
734	struct ioat_dma_descriptor *hw;
735	struct ioat_ring_ent *desc;
736	dma_addr_t dst = dma_dest;
737	dma_addr_t src = dma_src;
738	size_t total_len = len;
739	int num_descs, idx, i;
740
741	num_descs = ioat2_xferlen_to_descs(ioat, len);
742	if (likely(num_descs) && ioat2_check_space_lock(ioat, num_descs) == 0)
743		idx = ioat->head;
744	else
745		return NULL;
746	i = 0;
747	do {
748		size_t copy = min_t(size_t, len, 1 << ioat->xfercap_log);
749
750		desc = ioat2_get_ring_ent(ioat, idx + i);
751		hw = desc->hw;
752
753		hw->size = copy;
754		hw->ctl = 0;
755		hw->src_addr = src;
756		hw->dst_addr = dst;
757
758		len -= copy;
759		dst += copy;
760		src += copy;
761		dump_desc_dbg(ioat, desc);
762	} while (++i < num_descs);
763
764	desc->txd.flags = flags;
765	desc->len = total_len;
766	hw->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
767	hw->ctl_f.fence = !!(flags & DMA_PREP_FENCE);
768	hw->ctl_f.compl_write = 1;
769	dump_desc_dbg(ioat, desc);
770	/* we leave the channel locked to ensure in order submission */
771
772	return &desc->txd;
773}
774
775/**
776 * ioat2_free_chan_resources - release all the descriptors
777 * @chan: the channel to be cleaned
778 */
779void ioat2_free_chan_resources(struct dma_chan *c)
780{
781	struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
782	struct ioat_chan_common *chan = &ioat->base;
783	struct ioatdma_device *device = chan->device;
784	struct ioat_ring_ent *desc;
785	const u16 total_descs = 1 << ioat->alloc_order;
786	int descs;
787	int i;
788
789	/* Before freeing channel resources first check
790	 * if they have been previously allocated for this channel.
791	 */
792	if (!ioat->ring)
793		return;
794
795	tasklet_disable(&chan->cleanup_task);
796	del_timer_sync(&chan->timer);
797	device->cleanup_fn((unsigned long) c);
798	device->reset_hw(chan);
799	clear_bit(IOAT_RUN, &chan->state);
800
801	spin_lock_bh(&chan->cleanup_lock);
802	spin_lock_bh(&ioat->prep_lock);
803	descs = ioat2_ring_space(ioat);
804	dev_dbg(to_dev(chan), "freeing %d idle descriptors\n", descs);
805	for (i = 0; i < descs; i++) {
806		desc = ioat2_get_ring_ent(ioat, ioat->head + i);
807		ioat2_free_ring_ent(desc, c);
808	}
809
810	if (descs < total_descs)
811		dev_err(to_dev(chan), "Freeing %d in use descriptors!\n",
812			total_descs - descs);
813
814	for (i = 0; i < total_descs - descs; i++) {
815		desc = ioat2_get_ring_ent(ioat, ioat->tail + i);
816		dump_desc_dbg(ioat, desc);
817		ioat2_free_ring_ent(desc, c);
818	}
819
820	kfree(ioat->ring);
821	ioat->ring = NULL;
822	ioat->alloc_order = 0;
823	pci_pool_free(device->completion_pool, chan->completion,
824		      chan->completion_dma);
825	spin_unlock_bh(&ioat->prep_lock);
826	spin_unlock_bh(&chan->cleanup_lock);
827
828	chan->last_completion = 0;
829	chan->completion_dma = 0;
830	ioat->dmacount = 0;
831}
832
833static ssize_t ring_size_show(struct dma_chan *c, char *page)
834{
835	struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
836
837	return sprintf(page, "%d\n", (1 << ioat->alloc_order) & ~1);
838}
839static struct ioat_sysfs_entry ring_size_attr = __ATTR_RO(ring_size);
840
841static ssize_t ring_active_show(struct dma_chan *c, char *page)
842{
843	struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
844
845	/* ...taken outside the lock, no need to be precise */
846	return sprintf(page, "%d\n", ioat2_ring_active(ioat));
847}
848static struct ioat_sysfs_entry ring_active_attr = __ATTR_RO(ring_active);
849
850static struct attribute *ioat2_attrs[] = {
851	&ring_size_attr.attr,
852	&ring_active_attr.attr,
853	&ioat_cap_attr.attr,
854	&ioat_version_attr.attr,
855	NULL,
856};
857
858struct kobj_type ioat2_ktype = {
859	.sysfs_ops = &ioat_sysfs_ops,
860	.default_attrs = ioat2_attrs,
861};
862
863int __devinit ioat2_dma_probe(struct ioatdma_device *device, int dca)
864{
865	struct pci_dev *pdev = device->pdev;
866	struct dma_device *dma;
867	struct dma_chan *c;
868	struct ioat_chan_common *chan;
869	int err;
870
871	device->enumerate_channels = ioat2_enumerate_channels;
872	device->reset_hw = ioat2_reset_hw;
873	device->cleanup_fn = ioat2_cleanup_event;
874	device->timer_fn = ioat2_timer_event;
875	device->self_test = ioat_dma_self_test;
876	dma = &device->common;
877	dma->device_prep_dma_memcpy = ioat2_dma_prep_memcpy_lock;
878	dma->device_issue_pending = ioat2_issue_pending;
879	dma->device_alloc_chan_resources = ioat2_alloc_chan_resources;
880	dma->device_free_chan_resources = ioat2_free_chan_resources;
881	dma->device_tx_status = ioat_dma_tx_status;
882
883	err = ioat_probe(device);
884	if (err)
885		return err;
886	ioat_set_tcp_copy_break(2048);
887
888	list_for_each_entry(c, &dma->channels, device_node) {
889		chan = to_chan_common(c);
890		writel(IOAT_DCACTRL_CMPL_WRITE_ENABLE | IOAT_DMA_DCA_ANY_CPU,
891		       chan->reg_base + IOAT_DCACTRL_OFFSET);
892	}
893
894	err = ioat_register(device);
895	if (err)
896		return err;
897
898	ioat_kobject_add(device, &ioat2_ktype);
899
900	if (dca)
901		device->dca = ioat2_dca_init(pdev, device->reg_base);
902
903	return err;
904}
905