[go: nahoru, domu]

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 500
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		sdma_rb_node = kmalloc(sizeof(
230			struct qib_user_sdma_rb_node), GFP_KERNEL);
231		if (!sdma_rb_node)
232			goto err_rb;
233
234		sdma_rb_node->refcount = 1;
235		sdma_rb_node->pid = current->pid;
236
237		ret = qib_user_sdma_rb_insert(&qib_user_sdma_rb_root,
238					sdma_rb_node);
239		BUG_ON(ret == 0);
240	}
241	pq->sdma_rb_node = sdma_rb_node;
242
243	goto done;
244
245err_rb:
246	dma_pool_destroy(pq->header_cache);
247err_slab:
248	kmem_cache_destroy(pq->pkt_slab);
249err_kfree:
250	kfree(pq);
251	pq = NULL;
252
253done:
254	return pq;
255}
256
257static void qib_user_sdma_init_frag(struct qib_user_sdma_pkt *pkt,
258				    int i, u16 offset, u16 len,
259				    u16 first_desc, u16 last_desc,
260				    u16 put_page, u16 dma_mapped,
261				    struct page *page, void *kvaddr,
262				    dma_addr_t dma_addr, u16 dma_length)
263{
264	pkt->addr[i].offset = offset;
265	pkt->addr[i].length = len;
266	pkt->addr[i].first_desc = first_desc;
267	pkt->addr[i].last_desc = last_desc;
268	pkt->addr[i].put_page = put_page;
269	pkt->addr[i].dma_mapped = dma_mapped;
270	pkt->addr[i].page = page;
271	pkt->addr[i].kvaddr = kvaddr;
272	pkt->addr[i].addr = dma_addr;
273	pkt->addr[i].dma_length = dma_length;
274}
275
276static void *qib_user_sdma_alloc_header(struct qib_user_sdma_queue *pq,
277				size_t len, dma_addr_t *dma_addr)
278{
279	void *hdr;
280
281	if (len == QIB_USER_SDMA_EXP_HEADER_LENGTH)
282		hdr = dma_pool_alloc(pq->header_cache, GFP_KERNEL,
283					     dma_addr);
284	else
285		hdr = NULL;
286
287	if (!hdr) {
288		hdr = kmalloc(len, GFP_KERNEL);
289		if (!hdr)
290			return NULL;
291
292		*dma_addr = 0;
293	}
294
295	return hdr;
296}
297
298static int qib_user_sdma_page_to_frags(const struct qib_devdata *dd,
299				       struct qib_user_sdma_queue *pq,
300				       struct qib_user_sdma_pkt *pkt,
301				       struct page *page, u16 put,
302				       u16 offset, u16 len, void *kvaddr)
303{
304	__le16 *pbc16;
305	void *pbcvaddr;
306	struct qib_message_header *hdr;
307	u16 newlen, pbclen, lastdesc, dma_mapped;
308	u32 vcto;
309	union qib_seqnum seqnum;
310	dma_addr_t pbcdaddr;
311	dma_addr_t dma_addr =
312		dma_map_page(&dd->pcidev->dev,
313			page, offset, len, DMA_TO_DEVICE);
314	int ret = 0;
315
316	if (dma_mapping_error(&dd->pcidev->dev, dma_addr)) {
317		/*
318		 * dma mapping error, pkt has not managed
319		 * this page yet, return the page here so
320		 * the caller can ignore this page.
321		 */
322		if (put) {
323			put_page(page);
324		} else {
325			/* coalesce case */
326			kunmap(page);
327			__free_page(page);
328		}
329		ret = -ENOMEM;
330		goto done;
331	}
332	offset = 0;
333	dma_mapped = 1;
334
335
336next_fragment:
337
338	/*
339	 * In tid-sdma, the transfer length is restricted by
340	 * receiver side current tid page length.
341	 */
342	if (pkt->tiddma && len > pkt->tidsm[pkt->tidsmidx].length)
343		newlen = pkt->tidsm[pkt->tidsmidx].length;
344	else
345		newlen = len;
346
347	/*
348	 * Then the transfer length is restricted by MTU.
349	 * the last descriptor flag is determined by:
350	 * 1. the current packet is at frag size length.
351	 * 2. the current tid page is done if tid-sdma.
352	 * 3. there is no more byte togo if sdma.
353	 */
354	lastdesc = 0;
355	if ((pkt->payload_size + newlen) >= pkt->frag_size) {
356		newlen = pkt->frag_size - pkt->payload_size;
357		lastdesc = 1;
358	} else if (pkt->tiddma) {
359		if (newlen == pkt->tidsm[pkt->tidsmidx].length)
360			lastdesc = 1;
361	} else {
362		if (newlen == pkt->bytes_togo)
363			lastdesc = 1;
364	}
365
366	/* fill the next fragment in this page */
367	qib_user_sdma_init_frag(pkt, pkt->naddr, /* index */
368		offset, newlen,		/* offset, len */
369		0, lastdesc,		/* first last desc */
370		put, dma_mapped,	/* put page, dma mapped */
371		page, kvaddr,		/* struct page, virt addr */
372		dma_addr, len);		/* dma addr, dma length */
373	pkt->bytes_togo -= newlen;
374	pkt->payload_size += newlen;
375	pkt->naddr++;
376	if (pkt->naddr == pkt->addrlimit) {
377		ret = -EFAULT;
378		goto done;
379	}
380
381	/* If there is no more byte togo. (lastdesc==1) */
382	if (pkt->bytes_togo == 0) {
383		/* The packet is done, header is not dma mapped yet.
384		 * it should be from kmalloc */
385		if (!pkt->addr[pkt->index].addr) {
386			pkt->addr[pkt->index].addr =
387				dma_map_single(&dd->pcidev->dev,
388					pkt->addr[pkt->index].kvaddr,
389					pkt->addr[pkt->index].dma_length,
390					DMA_TO_DEVICE);
391			if (dma_mapping_error(&dd->pcidev->dev,
392					pkt->addr[pkt->index].addr)) {
393				ret = -ENOMEM;
394				goto done;
395			}
396			pkt->addr[pkt->index].dma_mapped = 1;
397		}
398
399		goto done;
400	}
401
402	/* If tid-sdma, advance tid info. */
403	if (pkt->tiddma) {
404		pkt->tidsm[pkt->tidsmidx].length -= newlen;
405		if (pkt->tidsm[pkt->tidsmidx].length) {
406			pkt->tidsm[pkt->tidsmidx].offset += newlen;
407		} else {
408			pkt->tidsmidx++;
409			if (pkt->tidsmidx == pkt->tidsmcount) {
410				ret = -EFAULT;
411				goto done;
412			}
413		}
414	}
415
416	/*
417	 * If this is NOT the last descriptor. (newlen==len)
418	 * the current packet is not done yet, but the current
419	 * send side page is done.
420	 */
421	if (lastdesc == 0)
422		goto done;
423
424	/*
425	 * If running this driver under PSM with message size
426	 * fitting into one transfer unit, it is not possible
427	 * to pass this line. otherwise, it is a buggggg.
428	 */
429
430	/*
431	 * Since the current packet is done, and there are more
432	 * bytes togo, we need to create a new sdma header, copying
433	 * from previous sdma header and modify both.
434	 */
435	pbclen = pkt->addr[pkt->index].length;
436	pbcvaddr = qib_user_sdma_alloc_header(pq, pbclen, &pbcdaddr);
437	if (!pbcvaddr) {
438		ret = -ENOMEM;
439		goto done;
440	}
441	/* Copy the previous sdma header to new sdma header */
442	pbc16 = (__le16 *)pkt->addr[pkt->index].kvaddr;
443	memcpy(pbcvaddr, pbc16, pbclen);
444
445	/* Modify the previous sdma header */
446	hdr = (struct qib_message_header *)&pbc16[4];
447
448	/* New pbc length */
449	pbc16[0] = cpu_to_le16(le16_to_cpu(pbc16[0])-(pkt->bytes_togo>>2));
450
451	/* New packet length */
452	hdr->lrh[2] = cpu_to_be16(le16_to_cpu(pbc16[0]));
453
454	if (pkt->tiddma) {
455		/* turn on the header suppression */
456		hdr->iph.pkt_flags =
457			cpu_to_le16(le16_to_cpu(hdr->iph.pkt_flags)|0x2);
458		/* turn off ACK_REQ: 0x04 and EXPECTED_DONE: 0x20 */
459		hdr->flags &= ~(0x04|0x20);
460	} else {
461		/* turn off extra bytes: 20-21 bits */
462		hdr->bth[0] = cpu_to_be32(be32_to_cpu(hdr->bth[0])&0xFFCFFFFF);
463		/* turn off ACK_REQ: 0x04 */
464		hdr->flags &= ~(0x04);
465	}
466
467	/* New kdeth checksum */
468	vcto = le32_to_cpu(hdr->iph.ver_ctxt_tid_offset);
469	hdr->iph.chksum = cpu_to_le16(QIB_LRH_BTH +
470		be16_to_cpu(hdr->lrh[2]) -
471		((vcto>>16)&0xFFFF) - (vcto&0xFFFF) -
472		le16_to_cpu(hdr->iph.pkt_flags));
473
474	/* The packet is done, header is not dma mapped yet.
475	 * it should be from kmalloc */
476	if (!pkt->addr[pkt->index].addr) {
477		pkt->addr[pkt->index].addr =
478			dma_map_single(&dd->pcidev->dev,
479				pkt->addr[pkt->index].kvaddr,
480				pkt->addr[pkt->index].dma_length,
481				DMA_TO_DEVICE);
482		if (dma_mapping_error(&dd->pcidev->dev,
483				pkt->addr[pkt->index].addr)) {
484			ret = -ENOMEM;
485			goto done;
486		}
487		pkt->addr[pkt->index].dma_mapped = 1;
488	}
489
490	/* Modify the new sdma header */
491	pbc16 = (__le16 *)pbcvaddr;
492	hdr = (struct qib_message_header *)&pbc16[4];
493
494	/* New pbc length */
495	pbc16[0] = cpu_to_le16(le16_to_cpu(pbc16[0])-(pkt->payload_size>>2));
496
497	/* New packet length */
498	hdr->lrh[2] = cpu_to_be16(le16_to_cpu(pbc16[0]));
499
500	if (pkt->tiddma) {
501		/* Set new tid and offset for new sdma header */
502		hdr->iph.ver_ctxt_tid_offset = cpu_to_le32(
503			(le32_to_cpu(hdr->iph.ver_ctxt_tid_offset)&0xFF000000) +
504			(pkt->tidsm[pkt->tidsmidx].tid<<QLOGIC_IB_I_TID_SHIFT) +
505			(pkt->tidsm[pkt->tidsmidx].offset>>2));
506	} else {
507		/* Middle protocol new packet offset */
508		hdr->uwords[2] += pkt->payload_size;
509	}
510
511	/* New kdeth checksum */
512	vcto = le32_to_cpu(hdr->iph.ver_ctxt_tid_offset);
513	hdr->iph.chksum = cpu_to_le16(QIB_LRH_BTH +
514		be16_to_cpu(hdr->lrh[2]) -
515		((vcto>>16)&0xFFFF) - (vcto&0xFFFF) -
516		le16_to_cpu(hdr->iph.pkt_flags));
517
518	/* Next sequence number in new sdma header */
519	seqnum.val = be32_to_cpu(hdr->bth[2]);
520	if (pkt->tiddma)
521		seqnum.seq++;
522	else
523		seqnum.pkt++;
524	hdr->bth[2] = cpu_to_be32(seqnum.val);
525
526	/* Init new sdma header. */
527	qib_user_sdma_init_frag(pkt, pkt->naddr, /* index */
528		0, pbclen,		/* offset, len */
529		1, 0,			/* first last desc */
530		0, 0,			/* put page, dma mapped */
531		NULL, pbcvaddr,		/* struct page, virt addr */
532		pbcdaddr, pbclen);	/* dma addr, dma length */
533	pkt->index = pkt->naddr;
534	pkt->payload_size = 0;
535	pkt->naddr++;
536	if (pkt->naddr == pkt->addrlimit) {
537		ret = -EFAULT;
538		goto done;
539	}
540
541	/* Prepare for next fragment in this page */
542	if (newlen != len) {
543		if (dma_mapped) {
544			put = 0;
545			dma_mapped = 0;
546			page = NULL;
547			kvaddr = NULL;
548		}
549		len -= newlen;
550		offset += newlen;
551
552		goto next_fragment;
553	}
554
555done:
556	return ret;
557}
558
559/* we've too many pages in the iovec, coalesce to a single page */
560static int qib_user_sdma_coalesce(const struct qib_devdata *dd,
561				  struct qib_user_sdma_queue *pq,
562				  struct qib_user_sdma_pkt *pkt,
563				  const struct iovec *iov,
564				  unsigned long niov)
565{
566	int ret = 0;
567	struct page *page = alloc_page(GFP_KERNEL);
568	void *mpage_save;
569	char *mpage;
570	int i;
571	int len = 0;
572
573	if (!page) {
574		ret = -ENOMEM;
575		goto done;
576	}
577
578	mpage = kmap(page);
579	mpage_save = mpage;
580	for (i = 0; i < niov; i++) {
581		int cfur;
582
583		cfur = copy_from_user(mpage,
584				      iov[i].iov_base, iov[i].iov_len);
585		if (cfur) {
586			ret = -EFAULT;
587			goto free_unmap;
588		}
589
590		mpage += iov[i].iov_len;
591		len += iov[i].iov_len;
592	}
593
594	ret = qib_user_sdma_page_to_frags(dd, pq, pkt,
595			page, 0, 0, len, mpage_save);
596	goto done;
597
598free_unmap:
599	kunmap(page);
600	__free_page(page);
601done:
602	return ret;
603}
604
605/*
606 * How many pages in this iovec element?
607 */
608static int qib_user_sdma_num_pages(const struct iovec *iov)
609{
610	const unsigned long addr  = (unsigned long) iov->iov_base;
611	const unsigned long  len  = iov->iov_len;
612	const unsigned long spage = addr & PAGE_MASK;
613	const unsigned long epage = (addr + len - 1) & PAGE_MASK;
614
615	return 1 + ((epage - spage) >> PAGE_SHIFT);
616}
617
618static void qib_user_sdma_free_pkt_frag(struct device *dev,
619					struct qib_user_sdma_queue *pq,
620					struct qib_user_sdma_pkt *pkt,
621					int frag)
622{
623	const int i = frag;
624
625	if (pkt->addr[i].page) {
626		/* only user data has page */
627		if (pkt->addr[i].dma_mapped)
628			dma_unmap_page(dev,
629				       pkt->addr[i].addr,
630				       pkt->addr[i].dma_length,
631				       DMA_TO_DEVICE);
632
633		if (pkt->addr[i].kvaddr)
634			kunmap(pkt->addr[i].page);
635
636		if (pkt->addr[i].put_page)
637			put_page(pkt->addr[i].page);
638		else
639			__free_page(pkt->addr[i].page);
640	} else if (pkt->addr[i].kvaddr) {
641		/* for headers */
642		if (pkt->addr[i].dma_mapped) {
643			/* from kmalloc & dma mapped */
644			dma_unmap_single(dev,
645				       pkt->addr[i].addr,
646				       pkt->addr[i].dma_length,
647				       DMA_TO_DEVICE);
648			kfree(pkt->addr[i].kvaddr);
649		} else if (pkt->addr[i].addr) {
650			/* free coherent mem from cache... */
651			dma_pool_free(pq->header_cache,
652			      pkt->addr[i].kvaddr, pkt->addr[i].addr);
653		} else {
654			/* from kmalloc but not dma mapped */
655			kfree(pkt->addr[i].kvaddr);
656		}
657	}
658}
659
660/* return number of pages pinned... */
661static int qib_user_sdma_pin_pages(const struct qib_devdata *dd,
662				   struct qib_user_sdma_queue *pq,
663				   struct qib_user_sdma_pkt *pkt,
664				   unsigned long addr, int tlen, int npages)
665{
666	struct page *pages[8];
667	int i, j;
668	int ret = 0;
669
670	while (npages) {
671		if (npages > 8)
672			j = 8;
673		else
674			j = npages;
675
676		ret = get_user_pages_fast(addr, j, 0, pages);
677		if (ret != j) {
678			i = 0;
679			j = ret;
680			ret = -ENOMEM;
681			goto free_pages;
682		}
683
684		for (i = 0; i < j; i++) {
685			/* map the pages... */
686			unsigned long fofs = addr & ~PAGE_MASK;
687			int flen = ((fofs + tlen) > PAGE_SIZE) ?
688				(PAGE_SIZE - fofs) : tlen;
689
690			ret = qib_user_sdma_page_to_frags(dd, pq, pkt,
691				pages[i], 1, fofs, flen, NULL);
692			if (ret < 0) {
693				/* current page has beed taken
694				 * care of inside above call.
695				 */
696				i++;
697				goto free_pages;
698			}
699
700			addr += flen;
701			tlen -= flen;
702		}
703
704		npages -= j;
705	}
706
707	goto done;
708
709	/* if error, return all pages not managed by pkt */
710free_pages:
711	while (i < j)
712		put_page(pages[i++]);
713
714done:
715	return ret;
716}
717
718static int qib_user_sdma_pin_pkt(const struct qib_devdata *dd,
719				 struct qib_user_sdma_queue *pq,
720				 struct qib_user_sdma_pkt *pkt,
721				 const struct iovec *iov,
722				 unsigned long niov)
723{
724	int ret = 0;
725	unsigned long idx;
726
727	for (idx = 0; idx < niov; idx++) {
728		const int npages = qib_user_sdma_num_pages(iov + idx);
729		const unsigned long addr = (unsigned long) iov[idx].iov_base;
730
731		ret = qib_user_sdma_pin_pages(dd, pq, pkt, addr,
732					      iov[idx].iov_len, npages);
733		if (ret < 0)
734			goto free_pkt;
735	}
736
737	goto done;
738
739free_pkt:
740	/* we need to ignore the first entry here */
741	for (idx = 1; idx < pkt->naddr; idx++)
742		qib_user_sdma_free_pkt_frag(&dd->pcidev->dev, pq, pkt, idx);
743
744	/* need to dma unmap the first entry, this is to restore to
745	 * the original state so that caller can free the memory in
746	 * error condition. Caller does not know if dma mapped or not*/
747	if (pkt->addr[0].dma_mapped) {
748		dma_unmap_single(&dd->pcidev->dev,
749		       pkt->addr[0].addr,
750		       pkt->addr[0].dma_length,
751		       DMA_TO_DEVICE);
752		pkt->addr[0].addr = 0;
753		pkt->addr[0].dma_mapped = 0;
754	}
755
756done:
757	return ret;
758}
759
760static int qib_user_sdma_init_payload(const struct qib_devdata *dd,
761				      struct qib_user_sdma_queue *pq,
762				      struct qib_user_sdma_pkt *pkt,
763				      const struct iovec *iov,
764				      unsigned long niov, int npages)
765{
766	int ret = 0;
767
768	if (pkt->frag_size == pkt->bytes_togo &&
769			npages >= ARRAY_SIZE(pkt->addr))
770		ret = qib_user_sdma_coalesce(dd, pq, pkt, iov, niov);
771	else
772		ret = qib_user_sdma_pin_pkt(dd, pq, pkt, iov, niov);
773
774	return ret;
775}
776
777/* free a packet list -- return counter value of last packet */
778static void qib_user_sdma_free_pkt_list(struct device *dev,
779					struct qib_user_sdma_queue *pq,
780					struct list_head *list)
781{
782	struct qib_user_sdma_pkt *pkt, *pkt_next;
783
784	list_for_each_entry_safe(pkt, pkt_next, list, list) {
785		int i;
786
787		for (i = 0; i < pkt->naddr; i++)
788			qib_user_sdma_free_pkt_frag(dev, pq, pkt, i);
789
790		if (pkt->largepkt)
791			kfree(pkt);
792		else
793			kmem_cache_free(pq->pkt_slab, pkt);
794	}
795	INIT_LIST_HEAD(list);
796}
797
798/*
799 * copy headers, coalesce etc -- pq->lock must be held
800 *
801 * we queue all the packets to list, returning the
802 * number of bytes total.  list must be empty initially,
803 * as, if there is an error we clean it...
804 */
805static int qib_user_sdma_queue_pkts(const struct qib_devdata *dd,
806				    struct qib_pportdata *ppd,
807				    struct qib_user_sdma_queue *pq,
808				    const struct iovec *iov,
809				    unsigned long niov,
810				    struct list_head *list,
811				    int *maxpkts, int *ndesc)
812{
813	unsigned long idx = 0;
814	int ret = 0;
815	int npkts = 0;
816	__le32 *pbc;
817	dma_addr_t dma_addr;
818	struct qib_user_sdma_pkt *pkt = NULL;
819	size_t len;
820	size_t nw;
821	u32 counter = pq->counter;
822	u16 frag_size;
823
824	while (idx < niov && npkts < *maxpkts) {
825		const unsigned long addr = (unsigned long) iov[idx].iov_base;
826		const unsigned long idx_save = idx;
827		unsigned pktnw;
828		unsigned pktnwc;
829		int nfrags = 0;
830		int npages = 0;
831		int bytes_togo = 0;
832		int tiddma = 0;
833		int cfur;
834
835		len = iov[idx].iov_len;
836		nw = len >> 2;
837
838		if (len < QIB_USER_SDMA_MIN_HEADER_LENGTH ||
839		    len > PAGE_SIZE || len & 3 || addr & 3) {
840			ret = -EINVAL;
841			goto free_list;
842		}
843
844		pbc = qib_user_sdma_alloc_header(pq, len, &dma_addr);
845		if (!pbc) {
846			ret = -ENOMEM;
847			goto free_list;
848		}
849
850		cfur = copy_from_user(pbc, iov[idx].iov_base, len);
851		if (cfur) {
852			ret = -EFAULT;
853			goto free_pbc;
854		}
855
856		/*
857		 * This assignment is a bit strange.  it's because the
858		 * the pbc counts the number of 32 bit words in the full
859		 * packet _except_ the first word of the pbc itself...
860		 */
861		pktnwc = nw - 1;
862
863		/*
864		 * pktnw computation yields the number of 32 bit words
865		 * that the caller has indicated in the PBC.  note that
866		 * this is one less than the total number of words that
867		 * goes to the send DMA engine as the first 32 bit word
868		 * of the PBC itself is not counted.  Armed with this count,
869		 * we can verify that the packet is consistent with the
870		 * iovec lengths.
871		 */
872		pktnw = le32_to_cpu(*pbc) & 0xFFFF;
873		if (pktnw < pktnwc) {
874			ret = -EINVAL;
875			goto free_pbc;
876		}
877
878		idx++;
879		while (pktnwc < pktnw && idx < niov) {
880			const size_t slen = iov[idx].iov_len;
881			const unsigned long faddr =
882				(unsigned long) iov[idx].iov_base;
883
884			if (slen & 3 || faddr & 3 || !slen) {
885				ret = -EINVAL;
886				goto free_pbc;
887			}
888
889			npages += qib_user_sdma_num_pages(&iov[idx]);
890
891			bytes_togo += slen;
892			pktnwc += slen >> 2;
893			idx++;
894			nfrags++;
895		}
896
897		if (pktnwc != pktnw) {
898			ret = -EINVAL;
899			goto free_pbc;
900		}
901
902		frag_size = ((le32_to_cpu(*pbc))>>16) & 0xFFFF;
903		if (((frag_size ? frag_size : bytes_togo) + len) >
904						ppd->ibmaxlen) {
905			ret = -EINVAL;
906			goto free_pbc;
907		}
908
909		if (frag_size) {
910			int pktsize, tidsmsize, n;
911
912			n = npages*((2*PAGE_SIZE/frag_size)+1);
913			pktsize = sizeof(*pkt) + sizeof(pkt->addr[0])*n;
914
915			/*
916			 * Determine if this is tid-sdma or just sdma.
917			 */
918			tiddma = (((le32_to_cpu(pbc[7])>>
919				QLOGIC_IB_I_TID_SHIFT)&
920				QLOGIC_IB_I_TID_MASK) !=
921				QLOGIC_IB_I_TID_MASK);
922
923			if (tiddma)
924				tidsmsize = iov[idx].iov_len;
925			else
926				tidsmsize = 0;
927
928			pkt = kmalloc(pktsize+tidsmsize, GFP_KERNEL);
929			if (!pkt) {
930				ret = -ENOMEM;
931				goto free_pbc;
932			}
933			pkt->largepkt = 1;
934			pkt->frag_size = frag_size;
935			pkt->addrlimit = n + ARRAY_SIZE(pkt->addr);
936
937			if (tiddma) {
938				char *tidsm = (char *)pkt + pktsize;
939				cfur = copy_from_user(tidsm,
940					iov[idx].iov_base, tidsmsize);
941				if (cfur) {
942					ret = -EFAULT;
943					goto free_pkt;
944				}
945				pkt->tidsm =
946					(struct qib_tid_session_member *)tidsm;
947				pkt->tidsmcount = tidsmsize/
948					sizeof(struct qib_tid_session_member);
949				pkt->tidsmidx = 0;
950				idx++;
951			}
952
953			/*
954			 * pbc 'fill1' field is borrowed to pass frag size,
955			 * we need to clear it after picking frag size, the
956			 * hardware requires this field to be zero.
957			 */
958			*pbc = cpu_to_le32(le32_to_cpu(*pbc) & 0x0000FFFF);
959		} else {
960			pkt = kmem_cache_alloc(pq->pkt_slab, GFP_KERNEL);
961			if (!pkt) {
962				ret = -ENOMEM;
963				goto free_pbc;
964			}
965			pkt->largepkt = 0;
966			pkt->frag_size = bytes_togo;
967			pkt->addrlimit = ARRAY_SIZE(pkt->addr);
968		}
969		pkt->bytes_togo = bytes_togo;
970		pkt->payload_size = 0;
971		pkt->counter = counter;
972		pkt->tiddma = tiddma;
973
974		/* setup the first header */
975		qib_user_sdma_init_frag(pkt, 0, /* index */
976			0, len,		/* offset, len */
977			1, 0,		/* first last desc */
978			0, 0,		/* put page, dma mapped */
979			NULL, pbc,	/* struct page, virt addr */
980			dma_addr, len);	/* dma addr, dma length */
981		pkt->index = 0;
982		pkt->naddr = 1;
983
984		if (nfrags) {
985			ret = qib_user_sdma_init_payload(dd, pq, pkt,
986							 iov + idx_save + 1,
987							 nfrags, npages);
988			if (ret < 0)
989				goto free_pkt;
990		} else {
991			/* since there is no payload, mark the
992			 * header as the last desc. */
993			pkt->addr[0].last_desc = 1;
994
995			if (dma_addr == 0) {
996				/*
997				 * the header is not dma mapped yet.
998				 * it should be from kmalloc.
999				 */
1000				dma_addr = dma_map_single(&dd->pcidev->dev,
1001					pbc, len, DMA_TO_DEVICE);
1002				if (dma_mapping_error(&dd->pcidev->dev,
1003								dma_addr)) {
1004					ret = -ENOMEM;
1005					goto free_pkt;
1006				}
1007				pkt->addr[0].addr = dma_addr;
1008				pkt->addr[0].dma_mapped = 1;
1009			}
1010		}
1011
1012		counter++;
1013		npkts++;
1014		pkt->pq = pq;
1015		pkt->index = 0; /* reset index for push on hw */
1016		*ndesc += pkt->naddr;
1017
1018		list_add_tail(&pkt->list, list);
1019	}
1020
1021	*maxpkts = npkts;
1022	ret = idx;
1023	goto done;
1024
1025free_pkt:
1026	if (pkt->largepkt)
1027		kfree(pkt);
1028	else
1029		kmem_cache_free(pq->pkt_slab, pkt);
1030free_pbc:
1031	if (dma_addr)
1032		dma_pool_free(pq->header_cache, pbc, dma_addr);
1033	else
1034		kfree(pbc);
1035free_list:
1036	qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, list);
1037done:
1038	return ret;
1039}
1040
1041static void qib_user_sdma_set_complete_counter(struct qib_user_sdma_queue *pq,
1042					       u32 c)
1043{
1044	pq->sent_counter = c;
1045}
1046
1047/* try to clean out queue -- needs pq->lock */
1048static int qib_user_sdma_queue_clean(struct qib_pportdata *ppd,
1049				     struct qib_user_sdma_queue *pq)
1050{
1051	struct qib_devdata *dd = ppd->dd;
1052	struct list_head free_list;
1053	struct qib_user_sdma_pkt *pkt;
1054	struct qib_user_sdma_pkt *pkt_prev;
1055	unsigned long flags;
1056	int ret = 0;
1057
1058	if (!pq->num_sending)
1059		return 0;
1060
1061	INIT_LIST_HEAD(&free_list);
1062
1063	/*
1064	 * We need this spin lock here because interrupt handler
1065	 * might modify this list in qib_user_sdma_send_desc(), also
1066	 * we can not get interrupted, otherwise it is a deadlock.
1067	 */
1068	spin_lock_irqsave(&pq->sent_lock, flags);
1069	list_for_each_entry_safe(pkt, pkt_prev, &pq->sent, list) {
1070		s64 descd = ppd->sdma_descq_removed - pkt->added;
1071
1072		if (descd < 0)
1073			break;
1074
1075		list_move_tail(&pkt->list, &free_list);
1076
1077		/* one more packet cleaned */
1078		ret++;
1079		pq->num_sending--;
1080	}
1081	spin_unlock_irqrestore(&pq->sent_lock, flags);
1082
1083	if (!list_empty(&free_list)) {
1084		u32 counter;
1085
1086		pkt = list_entry(free_list.prev,
1087				 struct qib_user_sdma_pkt, list);
1088		counter = pkt->counter;
1089
1090		qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
1091		qib_user_sdma_set_complete_counter(pq, counter);
1092	}
1093
1094	return ret;
1095}
1096
1097void qib_user_sdma_queue_destroy(struct qib_user_sdma_queue *pq)
1098{
1099	if (!pq)
1100		return;
1101
1102	pq->sdma_rb_node->refcount--;
1103	if (pq->sdma_rb_node->refcount == 0) {
1104		rb_erase(&pq->sdma_rb_node->node, &qib_user_sdma_rb_root);
1105		kfree(pq->sdma_rb_node);
1106	}
1107	dma_pool_destroy(pq->header_cache);
1108	kmem_cache_destroy(pq->pkt_slab);
1109	kfree(pq);
1110}
1111
1112/* clean descriptor queue, returns > 0 if some elements cleaned */
1113static int qib_user_sdma_hwqueue_clean(struct qib_pportdata *ppd)
1114{
1115	int ret;
1116	unsigned long flags;
1117
1118	spin_lock_irqsave(&ppd->sdma_lock, flags);
1119	ret = qib_sdma_make_progress(ppd);
1120	spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1121
1122	return ret;
1123}
1124
1125/* we're in close, drain packets so that we can cleanup successfully... */
1126void qib_user_sdma_queue_drain(struct qib_pportdata *ppd,
1127			       struct qib_user_sdma_queue *pq)
1128{
1129	struct qib_devdata *dd = ppd->dd;
1130	unsigned long flags;
1131	int i;
1132
1133	if (!pq)
1134		return;
1135
1136	for (i = 0; i < QIB_USER_SDMA_DRAIN_TIMEOUT; i++) {
1137		mutex_lock(&pq->lock);
1138		if (!pq->num_pending && !pq->num_sending) {
1139			mutex_unlock(&pq->lock);
1140			break;
1141		}
1142		qib_user_sdma_hwqueue_clean(ppd);
1143		qib_user_sdma_queue_clean(ppd, pq);
1144		mutex_unlock(&pq->lock);
1145		msleep(10);
1146	}
1147
1148	if (pq->num_pending || pq->num_sending) {
1149		struct qib_user_sdma_pkt *pkt;
1150		struct qib_user_sdma_pkt *pkt_prev;
1151		struct list_head free_list;
1152
1153		mutex_lock(&pq->lock);
1154		spin_lock_irqsave(&ppd->sdma_lock, flags);
1155		/*
1156		 * Since we hold sdma_lock, it is safe without sent_lock.
1157		 */
1158		if (pq->num_pending) {
1159			list_for_each_entry_safe(pkt, pkt_prev,
1160					&ppd->sdma_userpending, list) {
1161				if (pkt->pq == pq) {
1162					list_move_tail(&pkt->list, &pq->sent);
1163					pq->num_pending--;
1164					pq->num_sending++;
1165				}
1166			}
1167		}
1168		spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1169
1170		qib_dev_err(dd, "user sdma lists not empty: forcing!\n");
1171		INIT_LIST_HEAD(&free_list);
1172		list_splice_init(&pq->sent, &free_list);
1173		pq->num_sending = 0;
1174		qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
1175		mutex_unlock(&pq->lock);
1176	}
1177}
1178
1179static inline __le64 qib_sdma_make_desc0(u8 gen,
1180					 u64 addr, u64 dwlen, u64 dwoffset)
1181{
1182	return cpu_to_le64(/* SDmaPhyAddr[31:0] */
1183			   ((addr & 0xfffffffcULL) << 32) |
1184			   /* SDmaGeneration[1:0] */
1185			   ((gen & 3ULL) << 30) |
1186			   /* SDmaDwordCount[10:0] */
1187			   ((dwlen & 0x7ffULL) << 16) |
1188			   /* SDmaBufOffset[12:2] */
1189			   (dwoffset & 0x7ffULL));
1190}
1191
1192static inline __le64 qib_sdma_make_first_desc0(__le64 descq)
1193{
1194	return descq | cpu_to_le64(1ULL << 12);
1195}
1196
1197static inline __le64 qib_sdma_make_last_desc0(__le64 descq)
1198{
1199					      /* last */  /* dma head */
1200	return descq | cpu_to_le64(1ULL << 11 | 1ULL << 13);
1201}
1202
1203static inline __le64 qib_sdma_make_desc1(u64 addr)
1204{
1205	/* SDmaPhyAddr[47:32] */
1206	return cpu_to_le64(addr >> 32);
1207}
1208
1209static void qib_user_sdma_send_frag(struct qib_pportdata *ppd,
1210				    struct qib_user_sdma_pkt *pkt, int idx,
1211				    unsigned ofs, u16 tail, u8 gen)
1212{
1213	const u64 addr = (u64) pkt->addr[idx].addr +
1214		(u64) pkt->addr[idx].offset;
1215	const u64 dwlen = (u64) pkt->addr[idx].length / 4;
1216	__le64 *descqp;
1217	__le64 descq0;
1218
1219	descqp = &ppd->sdma_descq[tail].qw[0];
1220
1221	descq0 = qib_sdma_make_desc0(gen, addr, dwlen, ofs);
1222	if (pkt->addr[idx].first_desc)
1223		descq0 = qib_sdma_make_first_desc0(descq0);
1224	if (pkt->addr[idx].last_desc) {
1225		descq0 = qib_sdma_make_last_desc0(descq0);
1226		if (ppd->sdma_intrequest) {
1227			descq0 |= cpu_to_le64(1ULL << 15);
1228			ppd->sdma_intrequest = 0;
1229		}
1230	}
1231
1232	descqp[0] = descq0;
1233	descqp[1] = qib_sdma_make_desc1(addr);
1234}
1235
1236void qib_user_sdma_send_desc(struct qib_pportdata *ppd,
1237				struct list_head *pktlist)
1238{
1239	struct qib_devdata *dd = ppd->dd;
1240	u16 nfree, nsent;
1241	u16 tail, tail_c;
1242	u8 gen, gen_c;
1243
1244	nfree = qib_sdma_descq_freecnt(ppd);
1245	if (!nfree)
1246		return;
1247
1248retry:
1249	nsent = 0;
1250	tail_c = tail = ppd->sdma_descq_tail;
1251	gen_c = gen = ppd->sdma_generation;
1252	while (!list_empty(pktlist)) {
1253		struct qib_user_sdma_pkt *pkt =
1254			list_entry(pktlist->next, struct qib_user_sdma_pkt,
1255				   list);
1256		int i, j, c = 0;
1257		unsigned ofs = 0;
1258		u16 dtail = tail;
1259
1260		for (i = pkt->index; i < pkt->naddr && nfree; i++) {
1261			qib_user_sdma_send_frag(ppd, pkt, i, ofs, tail, gen);
1262			ofs += pkt->addr[i].length >> 2;
1263
1264			if (++tail == ppd->sdma_descq_cnt) {
1265				tail = 0;
1266				++gen;
1267				ppd->sdma_intrequest = 1;
1268			} else if (tail == (ppd->sdma_descq_cnt>>1)) {
1269				ppd->sdma_intrequest = 1;
1270			}
1271			nfree--;
1272			if (pkt->addr[i].last_desc == 0)
1273				continue;
1274
1275			/*
1276			 * If the packet is >= 2KB mtu equivalent, we
1277			 * have to use the large buffers, and have to
1278			 * mark each descriptor as part of a large
1279			 * buffer packet.
1280			 */
1281			if (ofs > dd->piosize2kmax_dwords) {
1282				for (j = pkt->index; j <= i; j++) {
1283					ppd->sdma_descq[dtail].qw[0] |=
1284						cpu_to_le64(1ULL << 14);
1285					if (++dtail == ppd->sdma_descq_cnt)
1286						dtail = 0;
1287				}
1288			}
1289			c += i + 1 - pkt->index;
1290			pkt->index = i + 1; /* index for next first */
1291			tail_c = dtail = tail;
1292			gen_c = gen;
1293			ofs = 0;  /* reset for next packet */
1294		}
1295
1296		ppd->sdma_descq_added += c;
1297		nsent += c;
1298		if (pkt->index == pkt->naddr) {
1299			pkt->added = ppd->sdma_descq_added;
1300			pkt->pq->added = pkt->added;
1301			pkt->pq->num_pending--;
1302			spin_lock(&pkt->pq->sent_lock);
1303			pkt->pq->num_sending++;
1304			list_move_tail(&pkt->list, &pkt->pq->sent);
1305			spin_unlock(&pkt->pq->sent_lock);
1306		}
1307		if (!nfree || (nsent<<2) > ppd->sdma_descq_cnt)
1308			break;
1309	}
1310
1311	/* advance the tail on the chip if necessary */
1312	if (ppd->sdma_descq_tail != tail_c) {
1313		ppd->sdma_generation = gen_c;
1314		dd->f_sdma_update_tail(ppd, tail_c);
1315	}
1316
1317	if (nfree && !list_empty(pktlist))
1318		goto retry;
1319
1320	return;
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