1/*
2 * Copyright (c) 2007, 2008, 2009 QLogic Corporation. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses.  You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 *     Redistribution and use in source and binary forms, with or
11 *     without modification, are permitted provided that the following
12 *     conditions are met:
13 *
14 *      - Redistributions of source code must retain the above
15 *        copyright notice, this list of conditions and the following
16 *        disclaimer.
17 *
18 *      - Redistributions in binary form must reproduce the above
19 *        copyright notice, this list of conditions and the following
20 *        disclaimer in the documentation and/or other materials
21 *        provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32#include <linux/mm.h>
33#include <linux/types.h>
34#include <linux/device.h>
35#include <linux/dmapool.h>
36#include <linux/slab.h>
37#include <linux/list.h>
38#include <linux/highmem.h>
39#include <linux/io.h>
40#include <linux/uio.h>
41#include <linux/rbtree.h>
42#include <linux/spinlock.h>
43#include <linux/delay.h>
44
45#include "qib.h"
46#include "qib_user_sdma.h"
47
48/* minimum size of header */
49#define QIB_USER_SDMA_MIN_HEADER_LENGTH 64
50/* expected size of headers (for dma_pool) */
51#define QIB_USER_SDMA_EXP_HEADER_LENGTH 64
52/* attempt to drain the queue for 5secs */
53#define QIB_USER_SDMA_DRAIN_TIMEOUT 250
54
55/*
56 * track how many times a process open this driver.
57 */
58static struct rb_root qib_user_sdma_rb_root = RB_ROOT;
59
60struct qib_user_sdma_rb_node {
61	struct rb_node node;
62	int refcount;
63	pid_t pid;
64};
65
66struct qib_user_sdma_pkt {
67	struct list_head list;  /* list element */
68
69	u8  tiddma;		/* if this is NEW tid-sdma */
70	u8  largepkt;		/* this is large pkt from kmalloc */
71	u16 frag_size;		/* frag size used by PSM */
72	u16 index;              /* last header index or push index */
73	u16 naddr;              /* dimension of addr (1..3) ... */
74	u16 addrlimit;		/* addr array size */
75	u16 tidsmidx;		/* current tidsm index */
76	u16 tidsmcount;		/* tidsm array item count */
77	u16 payload_size;	/* payload size so far for header */
78	u32 bytes_togo;		/* bytes for processing */
79	u32 counter;            /* sdma pkts queued counter for this entry */
80	struct qib_tid_session_member *tidsm;	/* tid session member array */
81	struct qib_user_sdma_queue *pq;	/* which pq this pkt belongs to */
82	u64 added;              /* global descq number of entries */
83
84	struct {
85		u16 offset;                     /* offset for kvaddr, addr */
86		u16 length;                     /* length in page */
87		u16 first_desc;			/* first desc */
88		u16 last_desc;			/* last desc */
89		u16 put_page;                   /* should we put_page? */
90		u16 dma_mapped;                 /* is page dma_mapped? */
91		u16 dma_length;			/* for dma_unmap_page() */
92		u16 padding;
93		struct page *page;              /* may be NULL (coherent mem) */
94		void *kvaddr;                   /* FIXME: only for pio hack */
95		dma_addr_t addr;
96	} addr[4];   /* max pages, any more and we coalesce */
97};
98
99struct qib_user_sdma_queue {
100	/*
101	 * pkts sent to dma engine are queued on this
102	 * list head.  the type of the elements of this
103	 * list are struct qib_user_sdma_pkt...
104	 */
105	struct list_head sent;
106
107	/*
108	 * Because above list will be accessed by both process and
109	 * signal handler, we need a spinlock for it.
110	 */
111	spinlock_t sent_lock ____cacheline_aligned_in_smp;
112
113	/* headers with expected length are allocated from here... */
114	char header_cache_name[64];
115	struct dma_pool *header_cache;
116
117	/* packets are allocated from the slab cache... */
118	char pkt_slab_name[64];
119	struct kmem_cache *pkt_slab;
120
121	/* as packets go on the queued queue, they are counted... */
122	u32 counter;
123	u32 sent_counter;
124	/* pending packets, not sending yet */
125	u32 num_pending;
126	/* sending packets, not complete yet */
127	u32 num_sending;
128	/* global descq number of entry of last sending packet */
129	u64 added;
130
131	/* dma page table */
132	struct rb_root dma_pages_root;
133
134	struct qib_user_sdma_rb_node *sdma_rb_node;
135
136	/* protect everything above... */
137	struct mutex lock;
138};
139
140static struct qib_user_sdma_rb_node *
141qib_user_sdma_rb_search(struct rb_root *root, pid_t pid)
142{
143	struct qib_user_sdma_rb_node *sdma_rb_node;
144	struct rb_node *node = root->rb_node;
145
146	while (node) {
147		sdma_rb_node = container_of(node,
148			struct qib_user_sdma_rb_node, node);
149		if (pid < sdma_rb_node->pid)
150			node = node->rb_left;
151		else if (pid > sdma_rb_node->pid)
152			node = node->rb_right;
153		else
154			return sdma_rb_node;
155	}
156	return NULL;
157}
158
159static int
160qib_user_sdma_rb_insert(struct rb_root *root, struct qib_user_sdma_rb_node *new)
161{
162	struct rb_node **node = &(root->rb_node);
163	struct rb_node *parent = NULL;
164	struct qib_user_sdma_rb_node *got;
165
166	while (*node) {
167		got = container_of(*node, struct qib_user_sdma_rb_node, node);
168		parent = *node;
169		if (new->pid < got->pid)
170			node = &((*node)->rb_left);
171		else if (new->pid > got->pid)
172			node = &((*node)->rb_right);
173		else
174			return 0;
175	}
176
177	rb_link_node(&new->node, parent, node);
178	rb_insert_color(&new->node, root);
179	return 1;
180}
181
182struct qib_user_sdma_queue *
183qib_user_sdma_queue_create(struct device *dev, int unit, int ctxt, int sctxt)
184{
185	struct qib_user_sdma_queue *pq =
186		kmalloc(sizeof(struct qib_user_sdma_queue), GFP_KERNEL);
187	struct qib_user_sdma_rb_node *sdma_rb_node;
188
189	if (!pq)
190		goto done;
191
192	pq->counter = 0;
193	pq->sent_counter = 0;
194	pq->num_pending = 0;
195	pq->num_sending = 0;
196	pq->added = 0;
197	pq->sdma_rb_node = NULL;
198
199	INIT_LIST_HEAD(&pq->sent);
200	spin_lock_init(&pq->sent_lock);
201	mutex_init(&pq->lock);
202
203	snprintf(pq->pkt_slab_name, sizeof(pq->pkt_slab_name),
204		 "qib-user-sdma-pkts-%u-%02u.%02u", unit, ctxt, sctxt);
205	pq->pkt_slab = kmem_cache_create(pq->pkt_slab_name,
206					 sizeof(struct qib_user_sdma_pkt),
207					 0, 0, NULL);
208
209	if (!pq->pkt_slab)
210		goto err_kfree;
211
212	snprintf(pq->header_cache_name, sizeof(pq->header_cache_name),
213		 "qib-user-sdma-headers-%u-%02u.%02u", unit, ctxt, sctxt);
214	pq->header_cache = dma_pool_create(pq->header_cache_name,
215					   dev,
216					   QIB_USER_SDMA_EXP_HEADER_LENGTH,
217					   4, 0);
218	if (!pq->header_cache)
219		goto err_slab;
220
221	pq->dma_pages_root = RB_ROOT;
222
223	sdma_rb_node = qib_user_sdma_rb_search(&qib_user_sdma_rb_root,
224					current->pid);
225	if (sdma_rb_node) {
226		sdma_rb_node->refcount++;
227	} else {
228		int ret;
229
230		sdma_rb_node = kmalloc(sizeof(
231			struct qib_user_sdma_rb_node), GFP_KERNEL);
232		if (!sdma_rb_node)
233			goto err_rb;
234
235		sdma_rb_node->refcount = 1;
236		sdma_rb_node->pid = current->pid;
237
238		ret = qib_user_sdma_rb_insert(&qib_user_sdma_rb_root,
239					sdma_rb_node);
240		BUG_ON(ret == 0);
241	}
242	pq->sdma_rb_node = sdma_rb_node;
243
244	goto done;
245
246err_rb:
247	dma_pool_destroy(pq->header_cache);
248err_slab:
249	kmem_cache_destroy(pq->pkt_slab);
250err_kfree:
251	kfree(pq);
252	pq = NULL;
253
254done:
255	return pq;
256}
257
258static void qib_user_sdma_init_frag(struct qib_user_sdma_pkt *pkt,
259				    int i, u16 offset, u16 len,
260				    u16 first_desc, u16 last_desc,
261				    u16 put_page, u16 dma_mapped,
262				    struct page *page, void *kvaddr,
263				    dma_addr_t dma_addr, u16 dma_length)
264{
265	pkt->addr[i].offset = offset;
266	pkt->addr[i].length = len;
267	pkt->addr[i].first_desc = first_desc;
268	pkt->addr[i].last_desc = last_desc;
269	pkt->addr[i].put_page = put_page;
270	pkt->addr[i].dma_mapped = dma_mapped;
271	pkt->addr[i].page = page;
272	pkt->addr[i].kvaddr = kvaddr;
273	pkt->addr[i].addr = dma_addr;
274	pkt->addr[i].dma_length = dma_length;
275}
276
277static void *qib_user_sdma_alloc_header(struct qib_user_sdma_queue *pq,
278				size_t len, dma_addr_t *dma_addr)
279{
280	void *hdr;
281
282	if (len == QIB_USER_SDMA_EXP_HEADER_LENGTH)
283		hdr = dma_pool_alloc(pq->header_cache, GFP_KERNEL,
284					     dma_addr);
285	else
286		hdr = NULL;
287
288	if (!hdr) {
289		hdr = kmalloc(len, GFP_KERNEL);
290		if (!hdr)
291			return NULL;
292
293		*dma_addr = 0;
294	}
295
296	return hdr;
297}
298
299static int qib_user_sdma_page_to_frags(const struct qib_devdata *dd,
300				       struct qib_user_sdma_queue *pq,
301				       struct qib_user_sdma_pkt *pkt,
302				       struct page *page, u16 put,
303				       u16 offset, u16 len, void *kvaddr)
304{
305	__le16 *pbc16;
306	void *pbcvaddr;
307	struct qib_message_header *hdr;
308	u16 newlen, pbclen, lastdesc, dma_mapped;
309	u32 vcto;
310	union qib_seqnum seqnum;
311	dma_addr_t pbcdaddr;
312	dma_addr_t dma_addr =
313		dma_map_page(&dd->pcidev->dev,
314			page, offset, len, DMA_TO_DEVICE);
315	int ret = 0;
316
317	if (dma_mapping_error(&dd->pcidev->dev, dma_addr)) {
318		/*
319		 * dma mapping error, pkt has not managed
320		 * this page yet, return the page here so
321		 * the caller can ignore this page.
322		 */
323		if (put) {
324			put_page(page);
325		} else {
326			/* coalesce case */
327			kunmap(page);
328			__free_page(page);
329		}
330		ret = -ENOMEM;
331		goto done;
332	}
333	offset = 0;
334	dma_mapped = 1;
335
336
337next_fragment:
338
339	/*
340	 * In tid-sdma, the transfer length is restricted by
341	 * receiver side current tid page length.
342	 */
343	if (pkt->tiddma && len > pkt->tidsm[pkt->tidsmidx].length)
344		newlen = pkt->tidsm[pkt->tidsmidx].length;
345	else
346		newlen = len;
347
348	/*
349	 * Then the transfer length is restricted by MTU.
350	 * the last descriptor flag is determined by:
351	 * 1. the current packet is at frag size length.
352	 * 2. the current tid page is done if tid-sdma.
353	 * 3. there is no more byte togo if sdma.
354	 */
355	lastdesc = 0;
356	if ((pkt->payload_size + newlen) >= pkt->frag_size) {
357		newlen = pkt->frag_size - pkt->payload_size;
358		lastdesc = 1;
359	} else if (pkt->tiddma) {
360		if (newlen == pkt->tidsm[pkt->tidsmidx].length)
361			lastdesc = 1;
362	} else {
363		if (newlen == pkt->bytes_togo)
364			lastdesc = 1;
365	}
366
367	/* fill the next fragment in this page */
368	qib_user_sdma_init_frag(pkt, pkt->naddr, /* index */
369		offset, newlen,		/* offset, len */
370		0, lastdesc,		/* first last desc */
371		put, dma_mapped,	/* put page, dma mapped */
372		page, kvaddr,		/* struct page, virt addr */
373		dma_addr, len);		/* dma addr, dma length */
374	pkt->bytes_togo -= newlen;
375	pkt->payload_size += newlen;
376	pkt->naddr++;
377	if (pkt->naddr == pkt->addrlimit) {
378		ret = -EFAULT;
379		goto done;
380	}
381
382	/* If there is no more byte togo. (lastdesc==1) */
383	if (pkt->bytes_togo == 0) {
384		/* The packet is done, header is not dma mapped yet.
385		 * it should be from kmalloc */
386		if (!pkt->addr[pkt->index].addr) {
387			pkt->addr[pkt->index].addr =
388				dma_map_single(&dd->pcidev->dev,
389					pkt->addr[pkt->index].kvaddr,
390					pkt->addr[pkt->index].dma_length,
391					DMA_TO_DEVICE);
392			if (dma_mapping_error(&dd->pcidev->dev,
393					pkt->addr[pkt->index].addr)) {
394				ret = -ENOMEM;
395				goto done;
396			}
397			pkt->addr[pkt->index].dma_mapped = 1;
398		}
399
400		goto done;
401	}
402
403	/* If tid-sdma, advance tid info. */
404	if (pkt->tiddma) {
405		pkt->tidsm[pkt->tidsmidx].length -= newlen;
406		if (pkt->tidsm[pkt->tidsmidx].length) {
407			pkt->tidsm[pkt->tidsmidx].offset += newlen;
408		} else {
409			pkt->tidsmidx++;
410			if (pkt->tidsmidx == pkt->tidsmcount) {
411				ret = -EFAULT;
412				goto done;
413			}
414		}
415	}
416
417	/*
418	 * If this is NOT the last descriptor. (newlen==len)
419	 * the current packet is not done yet, but the current
420	 * send side page is done.
421	 */
422	if (lastdesc == 0)
423		goto done;
424
425	/*
426	 * If running this driver under PSM with message size
427	 * fitting into one transfer unit, it is not possible
428	 * to pass this line. otherwise, it is a buggggg.
429	 */
430
431	/*
432	 * Since the current packet is done, and there are more
433	 * bytes togo, we need to create a new sdma header, copying
434	 * from previous sdma header and modify both.
435	 */
436	pbclen = pkt->addr[pkt->index].length;
437	pbcvaddr = qib_user_sdma_alloc_header(pq, pbclen, &pbcdaddr);
438	if (!pbcvaddr) {
439		ret = -ENOMEM;
440		goto done;
441	}
442	/* Copy the previous sdma header to new sdma header */
443	pbc16 = (__le16 *)pkt->addr[pkt->index].kvaddr;
444	memcpy(pbcvaddr, pbc16, pbclen);
445
446	/* Modify the previous sdma header */
447	hdr = (struct qib_message_header *)&pbc16[4];
448
449	/* New pbc length */
450	pbc16[0] = cpu_to_le16(le16_to_cpu(pbc16[0])-(pkt->bytes_togo>>2));
451
452	/* New packet length */
453	hdr->lrh[2] = cpu_to_be16(le16_to_cpu(pbc16[0]));
454
455	if (pkt->tiddma) {
456		/* turn on the header suppression */
457		hdr->iph.pkt_flags =
458			cpu_to_le16(le16_to_cpu(hdr->iph.pkt_flags)|0x2);
459		/* turn off ACK_REQ: 0x04 and EXPECTED_DONE: 0x20 */
460		hdr->flags &= ~(0x04|0x20);
461	} else {
462		/* turn off extra bytes: 20-21 bits */
463		hdr->bth[0] = cpu_to_be32(be32_to_cpu(hdr->bth[0])&0xFFCFFFFF);
464		/* turn off ACK_REQ: 0x04 */
465		hdr->flags &= ~(0x04);
466	}
467
468	/* New kdeth checksum */
469	vcto = le32_to_cpu(hdr->iph.ver_ctxt_tid_offset);
470	hdr->iph.chksum = cpu_to_le16(QIB_LRH_BTH +
471		be16_to_cpu(hdr->lrh[2]) -
472		((vcto>>16)&0xFFFF) - (vcto&0xFFFF) -
473		le16_to_cpu(hdr->iph.pkt_flags));
474
475	/* The packet is done, header is not dma mapped yet.
476	 * it should be from kmalloc */
477	if (!pkt->addr[pkt->index].addr) {
478		pkt->addr[pkt->index].addr =
479			dma_map_single(&dd->pcidev->dev,
480				pkt->addr[pkt->index].kvaddr,
481				pkt->addr[pkt->index].dma_length,
482				DMA_TO_DEVICE);
483		if (dma_mapping_error(&dd->pcidev->dev,
484				pkt->addr[pkt->index].addr)) {
485			ret = -ENOMEM;
486			goto done;
487		}
488		pkt->addr[pkt->index].dma_mapped = 1;
489	}
490
491	/* Modify the new sdma header */
492	pbc16 = (__le16 *)pbcvaddr;
493	hdr = (struct qib_message_header *)&pbc16[4];
494
495	/* New pbc length */
496	pbc16[0] = cpu_to_le16(le16_to_cpu(pbc16[0])-(pkt->payload_size>>2));
497
498	/* New packet length */
499	hdr->lrh[2] = cpu_to_be16(le16_to_cpu(pbc16[0]));
500
501	if (pkt->tiddma) {
502		/* Set new tid and offset for new sdma header */
503		hdr->iph.ver_ctxt_tid_offset = cpu_to_le32(
504			(le32_to_cpu(hdr->iph.ver_ctxt_tid_offset)&0xFF000000) +
505			(pkt->tidsm[pkt->tidsmidx].tid<<QLOGIC_IB_I_TID_SHIFT) +
506			(pkt->tidsm[pkt->tidsmidx].offset>>2));
507	} else {
508		/* Middle protocol new packet offset */
509		hdr->uwords[2] += pkt->payload_size;
510	}
511
512	/* New kdeth checksum */
513	vcto = le32_to_cpu(hdr->iph.ver_ctxt_tid_offset);
514	hdr->iph.chksum = cpu_to_le16(QIB_LRH_BTH +
515		be16_to_cpu(hdr->lrh[2]) -
516		((vcto>>16)&0xFFFF) - (vcto&0xFFFF) -
517		le16_to_cpu(hdr->iph.pkt_flags));
518
519	/* Next sequence number in new sdma header */
520	seqnum.val = be32_to_cpu(hdr->bth[2]);
521	if (pkt->tiddma)
522		seqnum.seq++;
523	else
524		seqnum.pkt++;
525	hdr->bth[2] = cpu_to_be32(seqnum.val);
526
527	/* Init new sdma header. */
528	qib_user_sdma_init_frag(pkt, pkt->naddr, /* index */
529		0, pbclen,		/* offset, len */
530		1, 0,			/* first last desc */
531		0, 0,			/* put page, dma mapped */
532		NULL, pbcvaddr,		/* struct page, virt addr */
533		pbcdaddr, pbclen);	/* dma addr, dma length */
534	pkt->index = pkt->naddr;
535	pkt->payload_size = 0;
536	pkt->naddr++;
537	if (pkt->naddr == pkt->addrlimit) {
538		ret = -EFAULT;
539		goto done;
540	}
541
542	/* Prepare for next fragment in this page */
543	if (newlen != len) {
544		if (dma_mapped) {
545			put = 0;
546			dma_mapped = 0;
547			page = NULL;
548			kvaddr = NULL;
549		}
550		len -= newlen;
551		offset += newlen;
552
553		goto next_fragment;
554	}
555
556done:
557	return ret;
558}
559
560/* we've too many pages in the iovec, coalesce to a single page */
561static int qib_user_sdma_coalesce(const struct qib_devdata *dd,
562				  struct qib_user_sdma_queue *pq,
563				  struct qib_user_sdma_pkt *pkt,
564				  const struct iovec *iov,
565				  unsigned long niov)
566{
567	int ret = 0;
568	struct page *page = alloc_page(GFP_KERNEL);
569	void *mpage_save;
570	char *mpage;
571	int i;
572	int len = 0;
573
574	if (!page) {
575		ret = -ENOMEM;
576		goto done;
577	}
578
579	mpage = kmap(page);
580	mpage_save = mpage;
581	for (i = 0; i < niov; i++) {
582		int cfur;
583
584		cfur = copy_from_user(mpage,
585				      iov[i].iov_base, iov[i].iov_len);
586		if (cfur) {
587			ret = -EFAULT;
588			goto free_unmap;
589		}
590
591		mpage += iov[i].iov_len;
592		len += iov[i].iov_len;
593	}
594
595	ret = qib_user_sdma_page_to_frags(dd, pq, pkt,
596			page, 0, 0, len, mpage_save);
597	goto done;
598
599free_unmap:
600	kunmap(page);
601	__free_page(page);
602done:
603	return ret;
604}
605
606/*
607 * How many pages in this iovec element?
608 */
609static int qib_user_sdma_num_pages(const struct iovec *iov)
610{
611	const unsigned long addr  = (unsigned long) iov->iov_base;
612	const unsigned long  len  = iov->iov_len;
613	const unsigned long spage = addr & PAGE_MASK;
614	const unsigned long epage = (addr + len - 1) & PAGE_MASK;
615
616	return 1 + ((epage - spage) >> PAGE_SHIFT);
617}
618
619static void qib_user_sdma_free_pkt_frag(struct device *dev,
620					struct qib_user_sdma_queue *pq,
621					struct qib_user_sdma_pkt *pkt,
622					int frag)
623{
624	const int i = frag;
625
626	if (pkt->addr[i].page) {
627		/* only user data has page */
628		if (pkt->addr[i].dma_mapped)
629			dma_unmap_page(dev,
630				       pkt->addr[i].addr,
631				       pkt->addr[i].dma_length,
632				       DMA_TO_DEVICE);
633
634		if (pkt->addr[i].kvaddr)
635			kunmap(pkt->addr[i].page);
636
637		if (pkt->addr[i].put_page)
638			put_page(pkt->addr[i].page);
639		else
640			__free_page(pkt->addr[i].page);
641	} else if (pkt->addr[i].kvaddr) {
642		/* for headers */
643		if (pkt->addr[i].dma_mapped) {
644			/* from kmalloc & dma mapped */
645			dma_unmap_single(dev,
646				       pkt->addr[i].addr,
647				       pkt->addr[i].dma_length,
648				       DMA_TO_DEVICE);
649			kfree(pkt->addr[i].kvaddr);
650		} else if (pkt->addr[i].addr) {
651			/* free coherent mem from cache... */
652			dma_pool_free(pq->header_cache,
653			      pkt->addr[i].kvaddr, pkt->addr[i].addr);
654		} else {
655			/* from kmalloc but not dma mapped */
656			kfree(pkt->addr[i].kvaddr);
657		}
658	}
659}
660
661/* return number of pages pinned... */
662static int qib_user_sdma_pin_pages(const struct qib_devdata *dd,
663				   struct qib_user_sdma_queue *pq,
664				   struct qib_user_sdma_pkt *pkt,
665				   unsigned long addr, int tlen, int npages)
666{
667	struct page *pages[8];
668	int i, j;
669	int ret = 0;
670
671	while (npages) {
672		if (npages > 8)
673			j = 8;
674		else
675			j = npages;
676
677		ret = get_user_pages_fast(addr, j, 0, pages);
678		if (ret != j) {
679			i = 0;
680			j = ret;
681			ret = -ENOMEM;
682			goto free_pages;
683		}
684
685		for (i = 0; i < j; i++) {
686			/* map the pages... */
687			unsigned long fofs = addr & ~PAGE_MASK;
688			int flen = ((fofs + tlen) > PAGE_SIZE) ?
689				(PAGE_SIZE - fofs) : tlen;
690
691			ret = qib_user_sdma_page_to_frags(dd, pq, pkt,
692				pages[i], 1, fofs, flen, NULL);
693			if (ret < 0) {
694				/* current page has beed taken
695				 * care of inside above call.
696				 */
697				i++;
698				goto free_pages;
699			}
700
701			addr += flen;
702			tlen -= flen;
703		}
704
705		npages -= j;
706	}
707
708	goto done;
709
710	/* if error, return all pages not managed by pkt */
711free_pages:
712	while (i < j)
713		put_page(pages[i++]);
714
715done:
716	return ret;
717}
718
719static int qib_user_sdma_pin_pkt(const struct qib_devdata *dd,
720				 struct qib_user_sdma_queue *pq,
721				 struct qib_user_sdma_pkt *pkt,
722				 const struct iovec *iov,
723				 unsigned long niov)
724{
725	int ret = 0;
726	unsigned long idx;
727
728	for (idx = 0; idx < niov; idx++) {
729		const int npages = qib_user_sdma_num_pages(iov + idx);
730		const unsigned long addr = (unsigned long) iov[idx].iov_base;
731
732		ret = qib_user_sdma_pin_pages(dd, pq, pkt, addr,
733					      iov[idx].iov_len, npages);
734		if (ret < 0)
735			goto free_pkt;
736	}
737
738	goto done;
739
740free_pkt:
741	/* we need to ignore the first entry here */
742	for (idx = 1; idx < pkt->naddr; idx++)
743		qib_user_sdma_free_pkt_frag(&dd->pcidev->dev, pq, pkt, idx);
744
745	/* need to dma unmap the first entry, this is to restore to
746	 * the original state so that caller can free the memory in
747	 * error condition. Caller does not know if dma mapped or not*/
748	if (pkt->addr[0].dma_mapped) {
749		dma_unmap_single(&dd->pcidev->dev,
750		       pkt->addr[0].addr,
751		       pkt->addr[0].dma_length,
752		       DMA_TO_DEVICE);
753		pkt->addr[0].addr = 0;
754		pkt->addr[0].dma_mapped = 0;
755	}
756
757done:
758	return ret;
759}
760
761static int qib_user_sdma_init_payload(const struct qib_devdata *dd,
762				      struct qib_user_sdma_queue *pq,
763				      struct qib_user_sdma_pkt *pkt,
764				      const struct iovec *iov,
765				      unsigned long niov, int npages)
766{
767	int ret = 0;
768
769	if (pkt->frag_size == pkt->bytes_togo &&
770			npages >= ARRAY_SIZE(pkt->addr))
771		ret = qib_user_sdma_coalesce(dd, pq, pkt, iov, niov);
772	else
773		ret = qib_user_sdma_pin_pkt(dd, pq, pkt, iov, niov);
774
775	return ret;
776}
777
778/* free a packet list -- return counter value of last packet */
779static void qib_user_sdma_free_pkt_list(struct device *dev,
780					struct qib_user_sdma_queue *pq,
781					struct list_head *list)
782{
783	struct qib_user_sdma_pkt *pkt, *pkt_next;
784
785	list_for_each_entry_safe(pkt, pkt_next, list, list) {
786		int i;
787
788		for (i = 0; i < pkt->naddr; i++)
789			qib_user_sdma_free_pkt_frag(dev, pq, pkt, i);
790
791		if (pkt->largepkt)
792			kfree(pkt);
793		else
794			kmem_cache_free(pq->pkt_slab, pkt);
795	}
796	INIT_LIST_HEAD(list);
797}
798
799/*
800 * copy headers, coalesce etc -- pq->lock must be held
801 *
802 * we queue all the packets to list, returning the
803 * number of bytes total.  list must be empty initially,
804 * as, if there is an error we clean it...
805 */
806static int qib_user_sdma_queue_pkts(const struct qib_devdata *dd,
807				    struct qib_pportdata *ppd,
808				    struct qib_user_sdma_queue *pq,
809				    const struct iovec *iov,
810				    unsigned long niov,
811				    struct list_head *list,
812				    int *maxpkts, int *ndesc)
813{
814	unsigned long idx = 0;
815	int ret = 0;
816	int npkts = 0;
817	__le32 *pbc;
818	dma_addr_t dma_addr;
819	struct qib_user_sdma_pkt *pkt = NULL;
820	size_t len;
821	size_t nw;
822	u32 counter = pq->counter;
823	u16 frag_size;
824
825	while (idx < niov && npkts < *maxpkts) {
826		const unsigned long addr = (unsigned long) iov[idx].iov_base;
827		const unsigned long idx_save = idx;
828		unsigned pktnw;
829		unsigned pktnwc;
830		int nfrags = 0;
831		int npages = 0;
832		int bytes_togo = 0;
833		int tiddma = 0;
834		int cfur;
835
836		len = iov[idx].iov_len;
837		nw = len >> 2;
838
839		if (len < QIB_USER_SDMA_MIN_HEADER_LENGTH ||
840		    len > PAGE_SIZE || len & 3 || addr & 3) {
841			ret = -EINVAL;
842			goto free_list;
843		}
844
845		pbc = qib_user_sdma_alloc_header(pq, len, &dma_addr);
846		if (!pbc) {
847			ret = -ENOMEM;
848			goto free_list;
849		}
850
851		cfur = copy_from_user(pbc, iov[idx].iov_base, len);
852		if (cfur) {
853			ret = -EFAULT;
854			goto free_pbc;
855		}
856
857		/*
858		 * This assignment is a bit strange.  it's because the
859		 * the pbc counts the number of 32 bit words in the full
860		 * packet _except_ the first word of the pbc itself...
861		 */
862		pktnwc = nw - 1;
863
864		/*
865		 * pktnw computation yields the number of 32 bit words
866		 * that the caller has indicated in the PBC.  note that
867		 * this is one less than the total number of words that
868		 * goes to the send DMA engine as the first 32 bit word
869		 * of the PBC itself is not counted.  Armed with this count,
870		 * we can verify that the packet is consistent with the
871		 * iovec lengths.
872		 */
873		pktnw = le32_to_cpu(*pbc) & 0xFFFF;
874		if (pktnw < pktnwc) {
875			ret = -EINVAL;
876			goto free_pbc;
877		}
878
879		idx++;
880		while (pktnwc < pktnw && idx < niov) {
881			const size_t slen = iov[idx].iov_len;
882			const unsigned long faddr =
883				(unsigned long) iov[idx].iov_base;
884
885			if (slen & 3 || faddr & 3 || !slen) {
886				ret = -EINVAL;
887				goto free_pbc;
888			}
889
890			npages += qib_user_sdma_num_pages(&iov[idx]);
891
892			bytes_togo += slen;
893			pktnwc += slen >> 2;
894			idx++;
895			nfrags++;
896		}
897
898		if (pktnwc != pktnw) {
899			ret = -EINVAL;
900			goto free_pbc;
901		}
902
903		frag_size = ((le32_to_cpu(*pbc))>>16) & 0xFFFF;
904		if (((frag_size ? frag_size : bytes_togo) + len) >
905						ppd->ibmaxlen) {
906			ret = -EINVAL;
907			goto free_pbc;
908		}
909
910		if (frag_size) {
911			int pktsize, tidsmsize, n;
912
913			n = npages*((2*PAGE_SIZE/frag_size)+1);
914			pktsize = sizeof(*pkt) + sizeof(pkt->addr[0])*n;
915
916			/*
917			 * Determine if this is tid-sdma or just sdma.
918			 */
919			tiddma = (((le32_to_cpu(pbc[7])>>
920				QLOGIC_IB_I_TID_SHIFT)&
921				QLOGIC_IB_I_TID_MASK) !=
922				QLOGIC_IB_I_TID_MASK);
923
924			if (tiddma)
925				tidsmsize = iov[idx].iov_len;
926			else
927				tidsmsize = 0;
928
929			pkt = kmalloc(pktsize+tidsmsize, GFP_KERNEL);
930			if (!pkt) {
931				ret = -ENOMEM;
932				goto free_pbc;
933			}
934			pkt->largepkt = 1;
935			pkt->frag_size = frag_size;
936			pkt->addrlimit = n + ARRAY_SIZE(pkt->addr);
937
938			if (tiddma) {
939				char *tidsm = (char *)pkt + pktsize;
940
941				cfur = copy_from_user(tidsm,
942					iov[idx].iov_base, tidsmsize);
943				if (cfur) {
944					ret = -EFAULT;
945					goto free_pkt;
946				}
947				pkt->tidsm =
948					(struct qib_tid_session_member *)tidsm;
949				pkt->tidsmcount = tidsmsize/
950					sizeof(struct qib_tid_session_member);
951				pkt->tidsmidx = 0;
952				idx++;
953			}
954
955			/*
956			 * pbc 'fill1' field is borrowed to pass frag size,
957			 * we need to clear it after picking frag size, the
958			 * hardware requires this field to be zero.
959			 */
960			*pbc = cpu_to_le32(le32_to_cpu(*pbc) & 0x0000FFFF);
961		} else {
962			pkt = kmem_cache_alloc(pq->pkt_slab, GFP_KERNEL);
963			if (!pkt) {
964				ret = -ENOMEM;
965				goto free_pbc;
966			}
967			pkt->largepkt = 0;
968			pkt->frag_size = bytes_togo;
969			pkt->addrlimit = ARRAY_SIZE(pkt->addr);
970		}
971		pkt->bytes_togo = bytes_togo;
972		pkt->payload_size = 0;
973		pkt->counter = counter;
974		pkt->tiddma = tiddma;
975
976		/* setup the first header */
977		qib_user_sdma_init_frag(pkt, 0, /* index */
978			0, len,		/* offset, len */
979			1, 0,		/* first last desc */
980			0, 0,		/* put page, dma mapped */
981			NULL, pbc,	/* struct page, virt addr */
982			dma_addr, len);	/* dma addr, dma length */
983		pkt->index = 0;
984		pkt->naddr = 1;
985
986		if (nfrags) {
987			ret = qib_user_sdma_init_payload(dd, pq, pkt,
988							 iov + idx_save + 1,
989							 nfrags, npages);
990			if (ret < 0)
991				goto free_pkt;
992		} else {
993			/* since there is no payload, mark the
994			 * header as the last desc. */
995			pkt->addr[0].last_desc = 1;
996
997			if (dma_addr == 0) {
998				/*
999				 * the header is not dma mapped yet.
1000				 * it should be from kmalloc.
1001				 */
1002				dma_addr = dma_map_single(&dd->pcidev->dev,
1003					pbc, len, DMA_TO_DEVICE);
1004				if (dma_mapping_error(&dd->pcidev->dev,
1005								dma_addr)) {
1006					ret = -ENOMEM;
1007					goto free_pkt;
1008				}
1009				pkt->addr[0].addr = dma_addr;
1010				pkt->addr[0].dma_mapped = 1;
1011			}
1012		}
1013
1014		counter++;
1015		npkts++;
1016		pkt->pq = pq;
1017		pkt->index = 0; /* reset index for push on hw */
1018		*ndesc += pkt->naddr;
1019
1020		list_add_tail(&pkt->list, list);
1021	}
1022
1023	*maxpkts = npkts;
1024	ret = idx;
1025	goto done;
1026
1027free_pkt:
1028	if (pkt->largepkt)
1029		kfree(pkt);
1030	else
1031		kmem_cache_free(pq->pkt_slab, pkt);
1032free_pbc:
1033	if (dma_addr)
1034		dma_pool_free(pq->header_cache, pbc, dma_addr);
1035	else
1036		kfree(pbc);
1037free_list:
1038	qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, list);
1039done:
1040	return ret;
1041}
1042
1043static void qib_user_sdma_set_complete_counter(struct qib_user_sdma_queue *pq,
1044					       u32 c)
1045{
1046	pq->sent_counter = c;
1047}
1048
1049/* try to clean out queue -- needs pq->lock */
1050static int qib_user_sdma_queue_clean(struct qib_pportdata *ppd,
1051				     struct qib_user_sdma_queue *pq)
1052{
1053	struct qib_devdata *dd = ppd->dd;
1054	struct list_head free_list;
1055	struct qib_user_sdma_pkt *pkt;
1056	struct qib_user_sdma_pkt *pkt_prev;
1057	unsigned long flags;
1058	int ret = 0;
1059
1060	if (!pq->num_sending)
1061		return 0;
1062
1063	INIT_LIST_HEAD(&free_list);
1064
1065	/*
1066	 * We need this spin lock here because interrupt handler
1067	 * might modify this list in qib_user_sdma_send_desc(), also
1068	 * we can not get interrupted, otherwise it is a deadlock.
1069	 */
1070	spin_lock_irqsave(&pq->sent_lock, flags);
1071	list_for_each_entry_safe(pkt, pkt_prev, &pq->sent, list) {
1072		s64 descd = ppd->sdma_descq_removed - pkt->added;
1073
1074		if (descd < 0)
1075			break;
1076
1077		list_move_tail(&pkt->list, &free_list);
1078
1079		/* one more packet cleaned */
1080		ret++;
1081		pq->num_sending--;
1082	}
1083	spin_unlock_irqrestore(&pq->sent_lock, flags);
1084
1085	if (!list_empty(&free_list)) {
1086		u32 counter;
1087
1088		pkt = list_entry(free_list.prev,
1089				 struct qib_user_sdma_pkt, list);
1090		counter = pkt->counter;
1091
1092		qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
1093		qib_user_sdma_set_complete_counter(pq, counter);
1094	}
1095
1096	return ret;
1097}
1098
1099void qib_user_sdma_queue_destroy(struct qib_user_sdma_queue *pq)
1100{
1101	if (!pq)
1102		return;
1103
1104	pq->sdma_rb_node->refcount--;
1105	if (pq->sdma_rb_node->refcount == 0) {
1106		rb_erase(&pq->sdma_rb_node->node, &qib_user_sdma_rb_root);
1107		kfree(pq->sdma_rb_node);
1108	}
1109	dma_pool_destroy(pq->header_cache);
1110	kmem_cache_destroy(pq->pkt_slab);
1111	kfree(pq);
1112}
1113
1114/* clean descriptor queue, returns > 0 if some elements cleaned */
1115static int qib_user_sdma_hwqueue_clean(struct qib_pportdata *ppd)
1116{
1117	int ret;
1118	unsigned long flags;
1119
1120	spin_lock_irqsave(&ppd->sdma_lock, flags);
1121	ret = qib_sdma_make_progress(ppd);
1122	spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1123
1124	return ret;
1125}
1126
1127/* we're in close, drain packets so that we can cleanup successfully... */
1128void qib_user_sdma_queue_drain(struct qib_pportdata *ppd,
1129			       struct qib_user_sdma_queue *pq)
1130{
1131	struct qib_devdata *dd = ppd->dd;
1132	unsigned long flags;
1133	int i;
1134
1135	if (!pq)
1136		return;
1137
1138	for (i = 0; i < QIB_USER_SDMA_DRAIN_TIMEOUT; i++) {
1139		mutex_lock(&pq->lock);
1140		if (!pq->num_pending && !pq->num_sending) {
1141			mutex_unlock(&pq->lock);
1142			break;
1143		}
1144		qib_user_sdma_hwqueue_clean(ppd);
1145		qib_user_sdma_queue_clean(ppd, pq);
1146		mutex_unlock(&pq->lock);
1147		msleep(20);
1148	}
1149
1150	if (pq->num_pending || pq->num_sending) {
1151		struct qib_user_sdma_pkt *pkt;
1152		struct qib_user_sdma_pkt *pkt_prev;
1153		struct list_head free_list;
1154
1155		mutex_lock(&pq->lock);
1156		spin_lock_irqsave(&ppd->sdma_lock, flags);
1157		/*
1158		 * Since we hold sdma_lock, it is safe without sent_lock.
1159		 */
1160		if (pq->num_pending) {
1161			list_for_each_entry_safe(pkt, pkt_prev,
1162					&ppd->sdma_userpending, list) {
1163				if (pkt->pq == pq) {
1164					list_move_tail(&pkt->list, &pq->sent);
1165					pq->num_pending--;
1166					pq->num_sending++;
1167				}
1168			}
1169		}
1170		spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1171
1172		qib_dev_err(dd, "user sdma lists not empty: forcing!\n");
1173		INIT_LIST_HEAD(&free_list);
1174		list_splice_init(&pq->sent, &free_list);
1175		pq->num_sending = 0;
1176		qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
1177		mutex_unlock(&pq->lock);
1178	}
1179}
1180
1181static inline __le64 qib_sdma_make_desc0(u8 gen,
1182					 u64 addr, u64 dwlen, u64 dwoffset)
1183{
1184	return cpu_to_le64(/* SDmaPhyAddr[31:0] */
1185			   ((addr & 0xfffffffcULL) << 32) |
1186			   /* SDmaGeneration[1:0] */
1187			   ((gen & 3ULL) << 30) |
1188			   /* SDmaDwordCount[10:0] */
1189			   ((dwlen & 0x7ffULL) << 16) |
1190			   /* SDmaBufOffset[12:2] */
1191			   (dwoffset & 0x7ffULL));
1192}
1193
1194static inline __le64 qib_sdma_make_first_desc0(__le64 descq)
1195{
1196	return descq | cpu_to_le64(1ULL << 12);
1197}
1198
1199static inline __le64 qib_sdma_make_last_desc0(__le64 descq)
1200{
1201					      /* last */  /* dma head */
1202	return descq | cpu_to_le64(1ULL << 11 | 1ULL << 13);
1203}
1204
1205static inline __le64 qib_sdma_make_desc1(u64 addr)
1206{
1207	/* SDmaPhyAddr[47:32] */
1208	return cpu_to_le64(addr >> 32);
1209}
1210
1211static void qib_user_sdma_send_frag(struct qib_pportdata *ppd,
1212				    struct qib_user_sdma_pkt *pkt, int idx,
1213				    unsigned ofs, u16 tail, u8 gen)
1214{
1215	const u64 addr = (u64) pkt->addr[idx].addr +
1216		(u64) pkt->addr[idx].offset;
1217	const u64 dwlen = (u64) pkt->addr[idx].length / 4;
1218	__le64 *descqp;
1219	__le64 descq0;
1220
1221	descqp = &ppd->sdma_descq[tail].qw[0];
1222
1223	descq0 = qib_sdma_make_desc0(gen, addr, dwlen, ofs);
1224	if (pkt->addr[idx].first_desc)
1225		descq0 = qib_sdma_make_first_desc0(descq0);
1226	if (pkt->addr[idx].last_desc) {
1227		descq0 = qib_sdma_make_last_desc0(descq0);
1228		if (ppd->sdma_intrequest) {
1229			descq0 |= cpu_to_le64(1ULL << 15);
1230			ppd->sdma_intrequest = 0;
1231		}
1232	}
1233
1234	descqp[0] = descq0;
1235	descqp[1] = qib_sdma_make_desc1(addr);
1236}
1237
1238void qib_user_sdma_send_desc(struct qib_pportdata *ppd,
1239				struct list_head *pktlist)
1240{
1241	struct qib_devdata *dd = ppd->dd;
1242	u16 nfree, nsent;
1243	u16 tail, tail_c;
1244	u8 gen, gen_c;
1245
1246	nfree = qib_sdma_descq_freecnt(ppd);
1247	if (!nfree)
1248		return;
1249
1250retry:
1251	nsent = 0;
1252	tail_c = tail = ppd->sdma_descq_tail;
1253	gen_c = gen = ppd->sdma_generation;
1254	while (!list_empty(pktlist)) {
1255		struct qib_user_sdma_pkt *pkt =
1256			list_entry(pktlist->next, struct qib_user_sdma_pkt,
1257				   list);
1258		int i, j, c = 0;
1259		unsigned ofs = 0;
1260		u16 dtail = tail;
1261
1262		for (i = pkt->index; i < pkt->naddr && nfree; i++) {
1263			qib_user_sdma_send_frag(ppd, pkt, i, ofs, tail, gen);
1264			ofs += pkt->addr[i].length >> 2;
1265
1266			if (++tail == ppd->sdma_descq_cnt) {
1267				tail = 0;
1268				++gen;
1269				ppd->sdma_intrequest = 1;
1270			} else if (tail == (ppd->sdma_descq_cnt>>1)) {
1271				ppd->sdma_intrequest = 1;
1272			}
1273			nfree--;
1274			if (pkt->addr[i].last_desc == 0)
1275				continue;
1276
1277			/*
1278			 * If the packet is >= 2KB mtu equivalent, we
1279			 * have to use the large buffers, and have to
1280			 * mark each descriptor as part of a large
1281			 * buffer packet.
1282			 */
1283			if (ofs > dd->piosize2kmax_dwords) {
1284				for (j = pkt->index; j <= i; j++) {
1285					ppd->sdma_descq[dtail].qw[0] |=
1286						cpu_to_le64(1ULL << 14);
1287					if (++dtail == ppd->sdma_descq_cnt)
1288						dtail = 0;
1289				}
1290			}
1291			c += i + 1 - pkt->index;
1292			pkt->index = i + 1; /* index for next first */
1293			tail_c = dtail = tail;
1294			gen_c = gen;
1295			ofs = 0;  /* reset for next packet */
1296		}
1297
1298		ppd->sdma_descq_added += c;
1299		nsent += c;
1300		if (pkt->index == pkt->naddr) {
1301			pkt->added = ppd->sdma_descq_added;
1302			pkt->pq->added = pkt->added;
1303			pkt->pq->num_pending--;
1304			spin_lock(&pkt->pq->sent_lock);
1305			pkt->pq->num_sending++;
1306			list_move_tail(&pkt->list, &pkt->pq->sent);
1307			spin_unlock(&pkt->pq->sent_lock);
1308		}
1309		if (!nfree || (nsent<<2) > ppd->sdma_descq_cnt)
1310			break;
1311	}
1312
1313	/* advance the tail on the chip if necessary */
1314	if (ppd->sdma_descq_tail != tail_c) {
1315		ppd->sdma_generation = gen_c;
1316		dd->f_sdma_update_tail(ppd, tail_c);
1317	}
1318
1319	if (nfree && !list_empty(pktlist))
1320		goto retry;
1321}
1322
1323/* pq->lock must be held, get packets on the wire... */
1324static int qib_user_sdma_push_pkts(struct qib_pportdata *ppd,
1325				 struct qib_user_sdma_queue *pq,
1326				 struct list_head *pktlist, int count)
1327{
1328	unsigned long flags;
1329
1330	if (unlikely(!(ppd->lflags & QIBL_LINKACTIVE)))
1331		return -ECOMM;
1332
1333	/* non-blocking mode */
1334	if (pq->sdma_rb_node->refcount > 1) {
1335		spin_lock_irqsave(&ppd->sdma_lock, flags);
1336		if (unlikely(!__qib_sdma_running(ppd))) {
1337			spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1338			return -ECOMM;
1339		}
1340		pq->num_pending += count;
1341		list_splice_tail_init(pktlist, &ppd->sdma_userpending);
1342		qib_user_sdma_send_desc(ppd, &ppd->sdma_userpending);
1343		spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1344		return 0;
1345	}
1346
1347	/* In this case, descriptors from this process are not
1348	 * linked to ppd pending queue, interrupt handler
1349	 * won't update this process, it is OK to directly
1350	 * modify without sdma lock.
1351	 */
1352
1353
1354	pq->num_pending += count;
1355	/*
1356	 * Blocking mode for single rail process, we must
1357	 * release/regain sdma_lock to give other process
1358	 * chance to make progress. This is important for
1359	 * performance.
1360	 */
1361	do {
1362		spin_lock_irqsave(&ppd->sdma_lock, flags);
1363		if (unlikely(!__qib_sdma_running(ppd))) {
1364			spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1365			return -ECOMM;
1366		}
1367		qib_user_sdma_send_desc(ppd, pktlist);
1368		if (!list_empty(pktlist))
1369			qib_sdma_make_progress(ppd);
1370		spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1371	} while (!list_empty(pktlist));
1372
1373	return 0;
1374}
1375
1376int qib_user_sdma_writev(struct qib_ctxtdata *rcd,
1377			 struct qib_user_sdma_queue *pq,
1378			 const struct iovec *iov,
1379			 unsigned long dim)
1380{
1381	struct qib_devdata *dd = rcd->dd;
1382	struct qib_pportdata *ppd = rcd->ppd;
1383	int ret = 0;
1384	struct list_head list;
1385	int npkts = 0;
1386
1387	INIT_LIST_HEAD(&list);
1388
1389	mutex_lock(&pq->lock);
1390
1391	/* why not -ECOMM like qib_user_sdma_push_pkts() below? */
1392	if (!qib_sdma_running(ppd))
1393		goto done_unlock;
1394
1395	/* if I have packets not complete yet */
1396	if (pq->added > ppd->sdma_descq_removed)
1397		qib_user_sdma_hwqueue_clean(ppd);
1398	/* if I have complete packets to be freed */
1399	if (pq->num_sending)
1400		qib_user_sdma_queue_clean(ppd, pq);
1401
1402	while (dim) {
1403		int mxp = 1;
1404		int ndesc = 0;
1405
1406		ret = qib_user_sdma_queue_pkts(dd, ppd, pq,
1407				iov, dim, &list, &mxp, &ndesc);
1408		if (ret < 0)
1409			goto done_unlock;
1410		else {
1411			dim -= ret;
1412			iov += ret;
1413		}
1414
1415		/* force packets onto the sdma hw queue... */
1416		if (!list_empty(&list)) {
1417			/*
1418			 * Lazily clean hw queue.
1419			 */
1420			if (qib_sdma_descq_freecnt(ppd) < ndesc) {
1421				qib_user_sdma_hwqueue_clean(ppd);
1422				if (pq->num_sending)
1423					qib_user_sdma_queue_clean(ppd, pq);
1424			}
1425
1426			ret = qib_user_sdma_push_pkts(ppd, pq, &list, mxp);
1427			if (ret < 0)
1428				goto done_unlock;
1429			else {
1430				npkts += mxp;
1431				pq->counter += mxp;
1432			}
1433		}
1434	}
1435
1436done_unlock:
1437	if (!list_empty(&list))
1438		qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &list);
1439	mutex_unlock(&pq->lock);
1440
1441	return (ret < 0) ? ret : npkts;
1442}
1443
1444int qib_user_sdma_make_progress(struct qib_pportdata *ppd,
1445				struct qib_user_sdma_queue *pq)
1446{
1447	int ret = 0;
1448
1449	mutex_lock(&pq->lock);
1450	qib_user_sdma_hwqueue_clean(ppd);
1451	ret = qib_user_sdma_queue_clean(ppd, pq);
1452	mutex_unlock(&pq->lock);
1453
1454	return ret;
1455}
1456
1457u32 qib_user_sdma_complete_counter(const struct qib_user_sdma_queue *pq)
1458{
1459	return pq ? pq->sent_counter : 0;
1460}
1461
1462u32 qib_user_sdma_inflight_counter(struct qib_user_sdma_queue *pq)
1463{
1464	return pq ? pq->counter : 0;
1465}
1466