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 = rb_entry(node, struct qib_user_sdma_rb_node,
148					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 = rb_entry(*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		sdma_rb_node = kmalloc(sizeof(
229			struct qib_user_sdma_rb_node), GFP_KERNEL);
230		if (!sdma_rb_node)
231			goto err_rb;
232
233		sdma_rb_node->refcount = 1;
234		sdma_rb_node->pid = current->pid;
235
236		qib_user_sdma_rb_insert(&qib_user_sdma_rb_root, sdma_rb_node);
237	}
238	pq->sdma_rb_node = sdma_rb_node;
239
240	goto done;
241
242err_rb:
243	dma_pool_destroy(pq->header_cache);
244err_slab:
245	kmem_cache_destroy(pq->pkt_slab);
246err_kfree:
247	kfree(pq);
248	pq = NULL;
249
250done:
251	return pq;
252}
253
254static void qib_user_sdma_init_frag(struct qib_user_sdma_pkt *pkt,
255				    int i, u16 offset, u16 len,
256				    u16 first_desc, u16 last_desc,
257				    u16 put_page, u16 dma_mapped,
258				    struct page *page, void *kvaddr,
259				    dma_addr_t dma_addr, u16 dma_length)
260{
261	pkt->addr[i].offset = offset;
262	pkt->addr[i].length = len;
263	pkt->addr[i].first_desc = first_desc;
264	pkt->addr[i].last_desc = last_desc;
265	pkt->addr[i].put_page = put_page;
266	pkt->addr[i].dma_mapped = dma_mapped;
267	pkt->addr[i].page = page;
268	pkt->addr[i].kvaddr = kvaddr;
269	pkt->addr[i].addr = dma_addr;
270	pkt->addr[i].dma_length = dma_length;
271}
272
273static void *qib_user_sdma_alloc_header(struct qib_user_sdma_queue *pq,
274				size_t len, dma_addr_t *dma_addr)
275{
276	void *hdr;
277
278	if (len == QIB_USER_SDMA_EXP_HEADER_LENGTH)
279		hdr = dma_pool_alloc(pq->header_cache, GFP_KERNEL,
280					     dma_addr);
281	else
282		hdr = NULL;
283
284	if (!hdr) {
285		hdr = kmalloc(len, GFP_KERNEL);
286		if (!hdr)
287			return NULL;
288
289		*dma_addr = 0;
290	}
291
292	return hdr;
293}
294
295static int qib_user_sdma_page_to_frags(const struct qib_devdata *dd,
296				       struct qib_user_sdma_queue *pq,
297				       struct qib_user_sdma_pkt *pkt,
298				       struct page *page, u16 put,
299				       u16 offset, u16 len, void *kvaddr)
300{
301	__le16 *pbc16;
302	void *pbcvaddr;
303	struct qib_message_header *hdr;
304	u16 newlen, pbclen, lastdesc, dma_mapped;
305	u32 vcto;
306	union qib_seqnum seqnum;
307	dma_addr_t pbcdaddr;
308	dma_addr_t dma_addr =
309		dma_map_page(&dd->pcidev->dev,
310			page, offset, len, DMA_TO_DEVICE);
311	int ret = 0;
312
313	if (dma_mapping_error(&dd->pcidev->dev, dma_addr)) {
314		/*
315		 * dma mapping error, pkt has not managed
316		 * this page yet, return the page here so
317		 * the caller can ignore this page.
318		 */
319		if (put) {
320			unpin_user_page(page);
321		} else {
322			/* coalesce case */
323			kunmap(page);
324			__free_page(page);
325		}
326		ret = -ENOMEM;
327		goto done;
328	}
329	offset = 0;
330	dma_mapped = 1;
331
332
333next_fragment:
334
335	/*
336	 * In tid-sdma, the transfer length is restricted by
337	 * receiver side current tid page length.
338	 */
339	if (pkt->tiddma && len > pkt->tidsm[pkt->tidsmidx].length)
340		newlen = pkt->tidsm[pkt->tidsmidx].length;
341	else
342		newlen = len;
343
344	/*
345	 * Then the transfer length is restricted by MTU.
346	 * the last descriptor flag is determined by:
347	 * 1. the current packet is at frag size length.
348	 * 2. the current tid page is done if tid-sdma.
349	 * 3. there is no more byte togo if sdma.
350	 */
351	lastdesc = 0;
352	if ((pkt->payload_size + newlen) >= pkt->frag_size) {
353		newlen = pkt->frag_size - pkt->payload_size;
354		lastdesc = 1;
355	} else if (pkt->tiddma) {
356		if (newlen == pkt->tidsm[pkt->tidsmidx].length)
357			lastdesc = 1;
358	} else {
359		if (newlen == pkt->bytes_togo)
360			lastdesc = 1;
361	}
362
363	/* fill the next fragment in this page */
364	qib_user_sdma_init_frag(pkt, pkt->naddr, /* index */
365		offset, newlen,		/* offset, len */
366		0, lastdesc,		/* first last desc */
367		put, dma_mapped,	/* put page, dma mapped */
368		page, kvaddr,		/* struct page, virt addr */
369		dma_addr, len);		/* dma addr, dma length */
370	pkt->bytes_togo -= newlen;
371	pkt->payload_size += newlen;
372	pkt->naddr++;
373	if (pkt->naddr == pkt->addrlimit) {
374		ret = -EFAULT;
375		goto done;
376	}
377
378	/* If there is no more byte togo. (lastdesc==1) */
379	if (pkt->bytes_togo == 0) {
380		/* The packet is done, header is not dma mapped yet.
381		 * it should be from kmalloc */
382		if (!pkt->addr[pkt->index].addr) {
383			pkt->addr[pkt->index].addr =
384				dma_map_single(&dd->pcidev->dev,
385					pkt->addr[pkt->index].kvaddr,
386					pkt->addr[pkt->index].dma_length,
387					DMA_TO_DEVICE);
388			if (dma_mapping_error(&dd->pcidev->dev,
389					pkt->addr[pkt->index].addr)) {
390				ret = -ENOMEM;
391				goto done;
392			}
393			pkt->addr[pkt->index].dma_mapped = 1;
394		}
395
396		goto done;
397	}
398
399	/* If tid-sdma, advance tid info. */
400	if (pkt->tiddma) {
401		pkt->tidsm[pkt->tidsmidx].length -= newlen;
402		if (pkt->tidsm[pkt->tidsmidx].length) {
403			pkt->tidsm[pkt->tidsmidx].offset += newlen;
404		} else {
405			pkt->tidsmidx++;
406			if (pkt->tidsmidx == pkt->tidsmcount) {
407				ret = -EFAULT;
408				goto done;
409			}
410		}
411	}
412
413	/*
414	 * If this is NOT the last descriptor. (newlen==len)
415	 * the current packet is not done yet, but the current
416	 * send side page is done.
417	 */
418	if (lastdesc == 0)
419		goto done;
420
421	/*
422	 * If running this driver under PSM with message size
423	 * fitting into one transfer unit, it is not possible
424	 * to pass this line. otherwise, it is a buggggg.
425	 */
426
427	/*
428	 * Since the current packet is done, and there are more
429	 * bytes togo, we need to create a new sdma header, copying
430	 * from previous sdma header and modify both.
431	 */
432	pbclen = pkt->addr[pkt->index].length;
433	pbcvaddr = qib_user_sdma_alloc_header(pq, pbclen, &pbcdaddr);
434	if (!pbcvaddr) {
435		ret = -ENOMEM;
436		goto done;
437	}
438	/* Copy the previous sdma header to new sdma header */
439	pbc16 = (__le16 *)pkt->addr[pkt->index].kvaddr;
440	memcpy(pbcvaddr, pbc16, pbclen);
441
442	/* Modify the previous sdma header */
443	hdr = (struct qib_message_header *)&pbc16[4];
444
445	/* New pbc length */
446	pbc16[0] = cpu_to_le16(le16_to_cpu(pbc16[0])-(pkt->bytes_togo>>2));
447
448	/* New packet length */
449	hdr->lrh[2] = cpu_to_be16(le16_to_cpu(pbc16[0]));
450
451	if (pkt->tiddma) {
452		/* turn on the header suppression */
453		hdr->iph.pkt_flags =
454			cpu_to_le16(le16_to_cpu(hdr->iph.pkt_flags)|0x2);
455		/* turn off ACK_REQ: 0x04 and EXPECTED_DONE: 0x20 */
456		hdr->flags &= ~(0x04|0x20);
457	} else {
458		/* turn off extra bytes: 20-21 bits */
459		hdr->bth[0] = cpu_to_be32(be32_to_cpu(hdr->bth[0])&0xFFCFFFFF);
460		/* turn off ACK_REQ: 0x04 */
461		hdr->flags &= ~(0x04);
462	}
463
464	/* New kdeth checksum */
465	vcto = le32_to_cpu(hdr->iph.ver_ctxt_tid_offset);
466	hdr->iph.chksum = cpu_to_le16(QIB_LRH_BTH +
467		be16_to_cpu(hdr->lrh[2]) -
468		((vcto>>16)&0xFFFF) - (vcto&0xFFFF) -
469		le16_to_cpu(hdr->iph.pkt_flags));
470
471	/* The packet is done, header is not dma mapped yet.
472	 * it should be from kmalloc */
473	if (!pkt->addr[pkt->index].addr) {
474		pkt->addr[pkt->index].addr =
475			dma_map_single(&dd->pcidev->dev,
476				pkt->addr[pkt->index].kvaddr,
477				pkt->addr[pkt->index].dma_length,
478				DMA_TO_DEVICE);
479		if (dma_mapping_error(&dd->pcidev->dev,
480				pkt->addr[pkt->index].addr)) {
481			ret = -ENOMEM;
482			goto done;
483		}
484		pkt->addr[pkt->index].dma_mapped = 1;
485	}
486
487	/* Modify the new sdma header */
488	pbc16 = (__le16 *)pbcvaddr;
489	hdr = (struct qib_message_header *)&pbc16[4];
490
491	/* New pbc length */
492	pbc16[0] = cpu_to_le16(le16_to_cpu(pbc16[0])-(pkt->payload_size>>2));
493
494	/* New packet length */
495	hdr->lrh[2] = cpu_to_be16(le16_to_cpu(pbc16[0]));
496
497	if (pkt->tiddma) {
498		/* Set new tid and offset for new sdma header */
499		hdr->iph.ver_ctxt_tid_offset = cpu_to_le32(
500			(le32_to_cpu(hdr->iph.ver_ctxt_tid_offset)&0xFF000000) +
501			(pkt->tidsm[pkt->tidsmidx].tid<<QLOGIC_IB_I_TID_SHIFT) +
502			(pkt->tidsm[pkt->tidsmidx].offset>>2));
503	} else {
504		/* Middle protocol new packet offset */
505		hdr->uwords[2] += pkt->payload_size;
506	}
507
508	/* New kdeth checksum */
509	vcto = le32_to_cpu(hdr->iph.ver_ctxt_tid_offset);
510	hdr->iph.chksum = cpu_to_le16(QIB_LRH_BTH +
511		be16_to_cpu(hdr->lrh[2]) -
512		((vcto>>16)&0xFFFF) - (vcto&0xFFFF) -
513		le16_to_cpu(hdr->iph.pkt_flags));
514
515	/* Next sequence number in new sdma header */
516	seqnum.val = be32_to_cpu(hdr->bth[2]);
517	if (pkt->tiddma)
518		seqnum.seq++;
519	else
520		seqnum.pkt++;
521	hdr->bth[2] = cpu_to_be32(seqnum.val);
522
523	/* Init new sdma header. */
524	qib_user_sdma_init_frag(pkt, pkt->naddr, /* index */
525		0, pbclen,		/* offset, len */
526		1, 0,			/* first last desc */
527		0, 0,			/* put page, dma mapped */
528		NULL, pbcvaddr,		/* struct page, virt addr */
529		pbcdaddr, pbclen);	/* dma addr, dma length */
530	pkt->index = pkt->naddr;
531	pkt->payload_size = 0;
532	pkt->naddr++;
533	if (pkt->naddr == pkt->addrlimit) {
534		ret = -EFAULT;
535		goto done;
536	}
537
538	/* Prepare for next fragment in this page */
539	if (newlen != len) {
540		if (dma_mapped) {
541			put = 0;
542			dma_mapped = 0;
543			page = NULL;
544			kvaddr = NULL;
545		}
546		len -= newlen;
547		offset += newlen;
548
549		goto next_fragment;
550	}
551
552done:
553	return ret;
554}
555
556/* we've too many pages in the iovec, coalesce to a single page */
557static int qib_user_sdma_coalesce(const struct qib_devdata *dd,
558				  struct qib_user_sdma_queue *pq,
559				  struct qib_user_sdma_pkt *pkt,
560				  const struct iovec *iov,
561				  unsigned long niov)
562{
563	int ret = 0;
564	struct page *page = alloc_page(GFP_KERNEL);
565	void *mpage_save;
566	char *mpage;
567	int i;
568	int len = 0;
569
570	if (!page) {
571		ret = -ENOMEM;
572		goto done;
573	}
574
575	mpage = kmap(page);
576	mpage_save = mpage;
577	for (i = 0; i < niov; i++) {
578		int cfur;
579
580		cfur = copy_from_user(mpage,
581				      iov[i].iov_base, iov[i].iov_len);
582		if (cfur) {
583			ret = -EFAULT;
584			goto free_unmap;
585		}
586
587		mpage += iov[i].iov_len;
588		len += iov[i].iov_len;
589	}
590
591	ret = qib_user_sdma_page_to_frags(dd, pq, pkt,
592			page, 0, 0, len, mpage_save);
593	goto done;
594
595free_unmap:
596	kunmap(page);
597	__free_page(page);
598done:
599	return ret;
600}
601
602/*
603 * How many pages in this iovec element?
604 */
605static size_t qib_user_sdma_num_pages(const struct iovec *iov)
606{
607	const unsigned long addr  = (unsigned long) iov->iov_base;
608	const unsigned long  len  = iov->iov_len;
609	const unsigned long spage = addr & PAGE_MASK;
610	const unsigned long epage = (addr + len - 1) & PAGE_MASK;
611
612	return 1 + ((epage - spage) >> PAGE_SHIFT);
613}
614
615static void qib_user_sdma_free_pkt_frag(struct device *dev,
616					struct qib_user_sdma_queue *pq,
617					struct qib_user_sdma_pkt *pkt,
618					int frag)
619{
620	const int i = frag;
621
622	if (pkt->addr[i].page) {
623		/* only user data has page */
624		if (pkt->addr[i].dma_mapped)
625			dma_unmap_page(dev,
626				       pkt->addr[i].addr,
627				       pkt->addr[i].dma_length,
628				       DMA_TO_DEVICE);
629
630		if (pkt->addr[i].kvaddr)
631			kunmap(pkt->addr[i].page);
632
633		if (pkt->addr[i].put_page)
634			unpin_user_page(pkt->addr[i].page);
635		else
636			__free_page(pkt->addr[i].page);
637	} else if (pkt->addr[i].kvaddr) {
638		/* for headers */
639		if (pkt->addr[i].dma_mapped) {
640			/* from kmalloc & dma mapped */
641			dma_unmap_single(dev,
642				       pkt->addr[i].addr,
643				       pkt->addr[i].dma_length,
644				       DMA_TO_DEVICE);
645			kfree(pkt->addr[i].kvaddr);
646		} else if (pkt->addr[i].addr) {
647			/* free coherent mem from cache... */
648			dma_pool_free(pq->header_cache,
649			      pkt->addr[i].kvaddr, pkt->addr[i].addr);
650		} else {
651			/* from kmalloc but not dma mapped */
652			kfree(pkt->addr[i].kvaddr);
653		}
654	}
655}
656
657/* return number of pages pinned... */
658static int qib_user_sdma_pin_pages(const struct qib_devdata *dd,
659				   struct qib_user_sdma_queue *pq,
660				   struct qib_user_sdma_pkt *pkt,
661				   unsigned long addr, int tlen, size_t npages)
662{
663	struct page *pages[8];
664	int i, j;
665	int ret = 0;
666
667	while (npages) {
668		if (npages > 8)
669			j = 8;
670		else
671			j = npages;
672
673		ret = pin_user_pages_fast(addr, j, FOLL_LONGTERM, pages);
674		if (ret != j) {
675			i = 0;
676			j = ret;
677			ret = -ENOMEM;
678			goto free_pages;
679		}
680
681		for (i = 0; i < j; i++) {
682			/* map the pages... */
683			unsigned long fofs = addr & ~PAGE_MASK;
684			int flen = ((fofs + tlen) > PAGE_SIZE) ?
685				(PAGE_SIZE - fofs) : tlen;
686
687			ret = qib_user_sdma_page_to_frags(dd, pq, pkt,
688				pages[i], 1, fofs, flen, NULL);
689			if (ret < 0) {
690				/* current page has beed taken
691				 * care of inside above call.
692				 */
693				i++;
694				goto free_pages;
695			}
696
697			addr += flen;
698			tlen -= flen;
699		}
700
701		npages -= j;
702	}
703
704	goto done;
705
706	/* if error, return all pages not managed by pkt */
707free_pages:
708	while (i < j)
709		unpin_user_page(pages[i++]);
710
711done:
712	return ret;
713}
714
715static int qib_user_sdma_pin_pkt(const struct qib_devdata *dd,
716				 struct qib_user_sdma_queue *pq,
717				 struct qib_user_sdma_pkt *pkt,
718				 const struct iovec *iov,
719				 unsigned long niov)
720{
721	int ret = 0;
722	unsigned long idx;
723
724	for (idx = 0; idx < niov; idx++) {
725		const size_t npages = qib_user_sdma_num_pages(iov + idx);
726		const unsigned long addr = (unsigned long) iov[idx].iov_base;
727
728		ret = qib_user_sdma_pin_pages(dd, pq, pkt, addr,
729					      iov[idx].iov_len, npages);
730		if (ret < 0)
731			goto free_pkt;
732	}
733
734	goto done;
735
736free_pkt:
737	/* we need to ignore the first entry here */
738	for (idx = 1; idx < pkt->naddr; idx++)
739		qib_user_sdma_free_pkt_frag(&dd->pcidev->dev, pq, pkt, idx);
740
741	/* need to dma unmap the first entry, this is to restore to
742	 * the original state so that caller can free the memory in
743	 * error condition. Caller does not know if dma mapped or not*/
744	if (pkt->addr[0].dma_mapped) {
745		dma_unmap_single(&dd->pcidev->dev,
746		       pkt->addr[0].addr,
747		       pkt->addr[0].dma_length,
748		       DMA_TO_DEVICE);
749		pkt->addr[0].addr = 0;
750		pkt->addr[0].dma_mapped = 0;
751	}
752
753done:
754	return ret;
755}
756
757static int qib_user_sdma_init_payload(const struct qib_devdata *dd,
758				      struct qib_user_sdma_queue *pq,
759				      struct qib_user_sdma_pkt *pkt,
760				      const struct iovec *iov,
761				      unsigned long niov, int npages)
762{
763	int ret = 0;
764
765	if (pkt->frag_size == pkt->bytes_togo &&
766			npages >= ARRAY_SIZE(pkt->addr))
767		ret = qib_user_sdma_coalesce(dd, pq, pkt, iov, niov);
768	else
769		ret = qib_user_sdma_pin_pkt(dd, pq, pkt, iov, niov);
770
771	return ret;
772}
773
774/* free a packet list -- return counter value of last packet */
775static void qib_user_sdma_free_pkt_list(struct device *dev,
776					struct qib_user_sdma_queue *pq,
777					struct list_head *list)
778{
779	struct qib_user_sdma_pkt *pkt, *pkt_next;
780
781	list_for_each_entry_safe(pkt, pkt_next, list, list) {
782		int i;
783
784		for (i = 0; i < pkt->naddr; i++)
785			qib_user_sdma_free_pkt_frag(dev, pq, pkt, i);
786
787		if (pkt->largepkt)
788			kfree(pkt);
789		else
790			kmem_cache_free(pq->pkt_slab, pkt);
791	}
792	INIT_LIST_HEAD(list);
793}
794
795/*
796 * copy headers, coalesce etc -- pq->lock must be held
797 *
798 * we queue all the packets to list, returning the
799 * number of bytes total.  list must be empty initially,
800 * as, if there is an error we clean it...
801 */
802static int qib_user_sdma_queue_pkts(const struct qib_devdata *dd,
803				    struct qib_pportdata *ppd,
804				    struct qib_user_sdma_queue *pq,
805				    const struct iovec *iov,
806				    unsigned long niov,
807				    struct list_head *list,
808				    int *maxpkts, int *ndesc)
809{
810	unsigned long idx = 0;
811	int ret = 0;
812	int npkts = 0;
813	__le32 *pbc;
814	dma_addr_t dma_addr;
815	struct qib_user_sdma_pkt *pkt = NULL;
816	size_t len;
817	size_t nw;
818	u32 counter = pq->counter;
819	u16 frag_size;
820
821	while (idx < niov && npkts < *maxpkts) {
822		const unsigned long addr = (unsigned long) iov[idx].iov_base;
823		const unsigned long idx_save = idx;
824		unsigned pktnw;
825		unsigned pktnwc;
826		int nfrags = 0;
827		size_t npages = 0;
828		size_t bytes_togo = 0;
829		int tiddma = 0;
830		int cfur;
831
832		len = iov[idx].iov_len;
833		nw = len >> 2;
834
835		if (len < QIB_USER_SDMA_MIN_HEADER_LENGTH ||
836		    len > PAGE_SIZE || len & 3 || addr & 3) {
837			ret = -EINVAL;
838			goto free_list;
839		}
840
841		pbc = qib_user_sdma_alloc_header(pq, len, &dma_addr);
842		if (!pbc) {
843			ret = -ENOMEM;
844			goto free_list;
845		}
846
847		cfur = copy_from_user(pbc, iov[idx].iov_base, len);
848		if (cfur) {
849			ret = -EFAULT;
850			goto free_pbc;
851		}
852
853		/*
854		 * This assignment is a bit strange.  it's because the
855		 * the pbc counts the number of 32 bit words in the full
856		 * packet _except_ the first word of the pbc itself...
857		 */
858		pktnwc = nw - 1;
859
860		/*
861		 * pktnw computation yields the number of 32 bit words
862		 * that the caller has indicated in the PBC.  note that
863		 * this is one less than the total number of words that
864		 * goes to the send DMA engine as the first 32 bit word
865		 * of the PBC itself is not counted.  Armed with this count,
866		 * we can verify that the packet is consistent with the
867		 * iovec lengths.
868		 */
869		pktnw = le32_to_cpu(*pbc) & 0xFFFF;
870		if (pktnw < pktnwc) {
871			ret = -EINVAL;
872			goto free_pbc;
873		}
874
875		idx++;
876		while (pktnwc < pktnw && idx < niov) {
877			const size_t slen = iov[idx].iov_len;
878			const unsigned long faddr =
879				(unsigned long) iov[idx].iov_base;
880
881			if (slen & 3 || faddr & 3 || !slen) {
882				ret = -EINVAL;
883				goto free_pbc;
884			}
885
886			npages += qib_user_sdma_num_pages(&iov[idx]);
887
888			if (check_add_overflow(bytes_togo, slen, &bytes_togo) ||
889			    bytes_togo > type_max(typeof(pkt->bytes_togo))) {
890				ret = -EINVAL;
891				goto free_pbc;
892			}
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			size_t tidsmsize, n, pktsize, sz, addrlimit;
912
913			n = npages*((2*PAGE_SIZE/frag_size)+1);
914			pktsize = struct_size(pkt, addr, 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			if (check_add_overflow(pktsize, tidsmsize, &sz)) {
930				ret = -EINVAL;
931				goto free_pbc;
932			}
933			pkt = kmalloc(sz, GFP_KERNEL);
934			if (!pkt) {
935				ret = -ENOMEM;
936				goto free_pbc;
937			}
938			pkt->largepkt = 1;
939			pkt->frag_size = frag_size;
940			if (check_add_overflow(n, ARRAY_SIZE(pkt->addr),
941					       &addrlimit) ||
942			    addrlimit > type_max(typeof(pkt->addrlimit))) {
943				ret = -EINVAL;
944				goto free_pkt;
945			}
946			pkt->addrlimit = addrlimit;
947
948			if (tiddma) {
949				char *tidsm = (char *)pkt + pktsize;
950
951				cfur = copy_from_user(tidsm,
952					iov[idx].iov_base, tidsmsize);
953				if (cfur) {
954					ret = -EFAULT;
955					goto free_pkt;
956				}
957				pkt->tidsm =
958					(struct qib_tid_session_member *)tidsm;
959				pkt->tidsmcount = tidsmsize/
960					sizeof(struct qib_tid_session_member);
961				pkt->tidsmidx = 0;
962				idx++;
963			}
964
965			/*
966			 * pbc 'fill1' field is borrowed to pass frag size,
967			 * we need to clear it after picking frag size, the
968			 * hardware requires this field to be zero.
969			 */
970			*pbc = cpu_to_le32(le32_to_cpu(*pbc) & 0x0000FFFF);
971		} else {
972			pkt = kmem_cache_alloc(pq->pkt_slab, GFP_KERNEL);
973			if (!pkt) {
974				ret = -ENOMEM;
975				goto free_pbc;
976			}
977			pkt->largepkt = 0;
978			pkt->frag_size = bytes_togo;
979			pkt->addrlimit = ARRAY_SIZE(pkt->addr);
980		}
981		pkt->bytes_togo = bytes_togo;
982		pkt->payload_size = 0;
983		pkt->counter = counter;
984		pkt->tiddma = tiddma;
985
986		/* setup the first header */
987		qib_user_sdma_init_frag(pkt, 0, /* index */
988			0, len,		/* offset, len */
989			1, 0,		/* first last desc */
990			0, 0,		/* put page, dma mapped */
991			NULL, pbc,	/* struct page, virt addr */
992			dma_addr, len);	/* dma addr, dma length */
993		pkt->index = 0;
994		pkt->naddr = 1;
995
996		if (nfrags) {
997			ret = qib_user_sdma_init_payload(dd, pq, pkt,
998							 iov + idx_save + 1,
999							 nfrags, npages);
1000			if (ret < 0)
1001				goto free_pkt;
1002		} else {
1003			/* since there is no payload, mark the
1004			 * header as the last desc. */
1005			pkt->addr[0].last_desc = 1;
1006
1007			if (dma_addr == 0) {
1008				/*
1009				 * the header is not dma mapped yet.
1010				 * it should be from kmalloc.
1011				 */
1012				dma_addr = dma_map_single(&dd->pcidev->dev,
1013					pbc, len, DMA_TO_DEVICE);
1014				if (dma_mapping_error(&dd->pcidev->dev,
1015								dma_addr)) {
1016					ret = -ENOMEM;
1017					goto free_pkt;
1018				}
1019				pkt->addr[0].addr = dma_addr;
1020				pkt->addr[0].dma_mapped = 1;
1021			}
1022		}
1023
1024		counter++;
1025		npkts++;
1026		pkt->pq = pq;
1027		pkt->index = 0; /* reset index for push on hw */
1028		*ndesc += pkt->naddr;
1029
1030		list_add_tail(&pkt->list, list);
1031	}
1032
1033	*maxpkts = npkts;
1034	ret = idx;
1035	goto done;
1036
1037free_pkt:
1038	if (pkt->largepkt)
1039		kfree(pkt);
1040	else
1041		kmem_cache_free(pq->pkt_slab, pkt);
1042free_pbc:
1043	if (dma_addr)
1044		dma_pool_free(pq->header_cache, pbc, dma_addr);
1045	else
1046		kfree(pbc);
1047free_list:
1048	qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, list);
1049done:
1050	return ret;
1051}
1052
1053static void qib_user_sdma_set_complete_counter(struct qib_user_sdma_queue *pq,
1054					       u32 c)
1055{
1056	pq->sent_counter = c;
1057}
1058
1059/* try to clean out queue -- needs pq->lock */
1060static int qib_user_sdma_queue_clean(struct qib_pportdata *ppd,
1061				     struct qib_user_sdma_queue *pq)
1062{
1063	struct qib_devdata *dd = ppd->dd;
1064	struct list_head free_list;
1065	struct qib_user_sdma_pkt *pkt;
1066	struct qib_user_sdma_pkt *pkt_prev;
1067	unsigned long flags;
1068	int ret = 0;
1069
1070	if (!pq->num_sending)
1071		return 0;
1072
1073	INIT_LIST_HEAD(&free_list);
1074
1075	/*
1076	 * We need this spin lock here because interrupt handler
1077	 * might modify this list in qib_user_sdma_send_desc(), also
1078	 * we can not get interrupted, otherwise it is a deadlock.
1079	 */
1080	spin_lock_irqsave(&pq->sent_lock, flags);
1081	list_for_each_entry_safe(pkt, pkt_prev, &pq->sent, list) {
1082		s64 descd = ppd->sdma_descq_removed - pkt->added;
1083
1084		if (descd < 0)
1085			break;
1086
1087		list_move_tail(&pkt->list, &free_list);
1088
1089		/* one more packet cleaned */
1090		ret++;
1091		pq->num_sending--;
1092	}
1093	spin_unlock_irqrestore(&pq->sent_lock, flags);
1094
1095	if (!list_empty(&free_list)) {
1096		u32 counter;
1097
1098		pkt = list_entry(free_list.prev,
1099				 struct qib_user_sdma_pkt, list);
1100		counter = pkt->counter;
1101
1102		qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
1103		qib_user_sdma_set_complete_counter(pq, counter);
1104	}
1105
1106	return ret;
1107}
1108
1109void qib_user_sdma_queue_destroy(struct qib_user_sdma_queue *pq)
1110{
1111	if (!pq)
1112		return;
1113
1114	pq->sdma_rb_node->refcount--;
1115	if (pq->sdma_rb_node->refcount == 0) {
1116		rb_erase(&pq->sdma_rb_node->node, &qib_user_sdma_rb_root);
1117		kfree(pq->sdma_rb_node);
1118	}
1119	dma_pool_destroy(pq->header_cache);
1120	kmem_cache_destroy(pq->pkt_slab);
1121	kfree(pq);
1122}
1123
1124/* clean descriptor queue, returns > 0 if some elements cleaned */
1125static int qib_user_sdma_hwqueue_clean(struct qib_pportdata *ppd)
1126{
1127	int ret;
1128	unsigned long flags;
1129
1130	spin_lock_irqsave(&ppd->sdma_lock, flags);
1131	ret = qib_sdma_make_progress(ppd);
1132	spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1133
1134	return ret;
1135}
1136
1137/* we're in close, drain packets so that we can cleanup successfully... */
1138void qib_user_sdma_queue_drain(struct qib_pportdata *ppd,
1139			       struct qib_user_sdma_queue *pq)
1140{
1141	struct qib_devdata *dd = ppd->dd;
1142	unsigned long flags;
1143	int i;
1144
1145	if (!pq)
1146		return;
1147
1148	for (i = 0; i < QIB_USER_SDMA_DRAIN_TIMEOUT; i++) {
1149		mutex_lock(&pq->lock);
1150		if (!pq->num_pending && !pq->num_sending) {
1151			mutex_unlock(&pq->lock);
1152			break;
1153		}
1154		qib_user_sdma_hwqueue_clean(ppd);
1155		qib_user_sdma_queue_clean(ppd, pq);
1156		mutex_unlock(&pq->lock);
1157		msleep(20);
1158	}
1159
1160	if (pq->num_pending || pq->num_sending) {
1161		struct qib_user_sdma_pkt *pkt;
1162		struct qib_user_sdma_pkt *pkt_prev;
1163		struct list_head free_list;
1164
1165		mutex_lock(&pq->lock);
1166		spin_lock_irqsave(&ppd->sdma_lock, flags);
1167		/*
1168		 * Since we hold sdma_lock, it is safe without sent_lock.
1169		 */
1170		if (pq->num_pending) {
1171			list_for_each_entry_safe(pkt, pkt_prev,
1172					&ppd->sdma_userpending, list) {
1173				if (pkt->pq == pq) {
1174					list_move_tail(&pkt->list, &pq->sent);
1175					pq->num_pending--;
1176					pq->num_sending++;
1177				}
1178			}
1179		}
1180		spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1181
1182		qib_dev_err(dd, "user sdma lists not empty: forcing!\n");
1183		INIT_LIST_HEAD(&free_list);
1184		list_splice_init(&pq->sent, &free_list);
1185		pq->num_sending = 0;
1186		qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
1187		mutex_unlock(&pq->lock);
1188	}
1189}
1190
1191static inline __le64 qib_sdma_make_desc0(u8 gen,
1192					 u64 addr, u64 dwlen, u64 dwoffset)
1193{
1194	return cpu_to_le64(/* SDmaPhyAddr[31:0] */
1195			   ((addr & 0xfffffffcULL) << 32) |
1196			   /* SDmaGeneration[1:0] */
1197			   ((gen & 3ULL) << 30) |
1198			   /* SDmaDwordCount[10:0] */
1199			   ((dwlen & 0x7ffULL) << 16) |
1200			   /* SDmaBufOffset[12:2] */
1201			   (dwoffset & 0x7ffULL));
1202}
1203
1204static inline __le64 qib_sdma_make_first_desc0(__le64 descq)
1205{
1206	return descq | cpu_to_le64(1ULL << 12);
1207}
1208
1209static inline __le64 qib_sdma_make_last_desc0(__le64 descq)
1210{
1211					      /* last */  /* dma head */
1212	return descq | cpu_to_le64(1ULL << 11 | 1ULL << 13);
1213}
1214
1215static inline __le64 qib_sdma_make_desc1(u64 addr)
1216{
1217	/* SDmaPhyAddr[47:32] */
1218	return cpu_to_le64(addr >> 32);
1219}
1220
1221static void qib_user_sdma_send_frag(struct qib_pportdata *ppd,
1222				    struct qib_user_sdma_pkt *pkt, int idx,
1223				    unsigned ofs, u16 tail, u8 gen)
1224{
1225	const u64 addr = (u64) pkt->addr[idx].addr +
1226		(u64) pkt->addr[idx].offset;
1227	const u64 dwlen = (u64) pkt->addr[idx].length / 4;
1228	__le64 *descqp;
1229	__le64 descq0;
1230
1231	descqp = &ppd->sdma_descq[tail].qw[0];
1232
1233	descq0 = qib_sdma_make_desc0(gen, addr, dwlen, ofs);
1234	if (pkt->addr[idx].first_desc)
1235		descq0 = qib_sdma_make_first_desc0(descq0);
1236	if (pkt->addr[idx].last_desc) {
1237		descq0 = qib_sdma_make_last_desc0(descq0);
1238		if (ppd->sdma_intrequest) {
1239			descq0 |= cpu_to_le64(1ULL << 15);
1240			ppd->sdma_intrequest = 0;
1241		}
1242	}
1243
1244	descqp[0] = descq0;
1245	descqp[1] = qib_sdma_make_desc1(addr);
1246}
1247
1248void qib_user_sdma_send_desc(struct qib_pportdata *ppd,
1249				struct list_head *pktlist)
1250{
1251	struct qib_devdata *dd = ppd->dd;
1252	u16 nfree, nsent;
1253	u16 tail, tail_c;
1254	u8 gen, gen_c;
1255
1256	nfree = qib_sdma_descq_freecnt(ppd);
1257	if (!nfree)
1258		return;
1259
1260retry:
1261	nsent = 0;
1262	tail_c = tail = ppd->sdma_descq_tail;
1263	gen_c = gen = ppd->sdma_generation;
1264	while (!list_empty(pktlist)) {
1265		struct qib_user_sdma_pkt *pkt =
1266			list_entry(pktlist->next, struct qib_user_sdma_pkt,
1267				   list);
1268		int i, j, c = 0;
1269		unsigned ofs = 0;
1270		u16 dtail = tail;
1271
1272		for (i = pkt->index; i < pkt->naddr && nfree; i++) {
1273			qib_user_sdma_send_frag(ppd, pkt, i, ofs, tail, gen);
1274			ofs += pkt->addr[i].length >> 2;
1275
1276			if (++tail == ppd->sdma_descq_cnt) {
1277				tail = 0;
1278				++gen;
1279				ppd->sdma_intrequest = 1;
1280			} else if (tail == (ppd->sdma_descq_cnt>>1)) {
1281				ppd->sdma_intrequest = 1;
1282			}
1283			nfree--;
1284			if (pkt->addr[i].last_desc == 0)
1285				continue;
1286
1287			/*
1288			 * If the packet is >= 2KB mtu equivalent, we
1289			 * have to use the large buffers, and have to
1290			 * mark each descriptor as part of a large
1291			 * buffer packet.
1292			 */
1293			if (ofs > dd->piosize2kmax_dwords) {
1294				for (j = pkt->index; j <= i; j++) {
1295					ppd->sdma_descq[dtail].qw[0] |=
1296						cpu_to_le64(1ULL << 14);
1297					if (++dtail == ppd->sdma_descq_cnt)
1298						dtail = 0;
1299				}
1300			}
1301			c += i + 1 - pkt->index;
1302			pkt->index = i + 1; /* index for next first */
1303			tail_c = dtail = tail;
1304			gen_c = gen;
1305			ofs = 0;  /* reset for next packet */
1306		}
1307
1308		ppd->sdma_descq_added += c;
1309		nsent += c;
1310		if (pkt->index == pkt->naddr) {
1311			pkt->added = ppd->sdma_descq_added;
1312			pkt->pq->added = pkt->added;
1313			pkt->pq->num_pending--;
1314			spin_lock(&pkt->pq->sent_lock);
1315			pkt->pq->num_sending++;
1316			list_move_tail(&pkt->list, &pkt->pq->sent);
1317			spin_unlock(&pkt->pq->sent_lock);
1318		}
1319		if (!nfree || (nsent<<2) > ppd->sdma_descq_cnt)
1320			break;
1321	}
1322
1323	/* advance the tail on the chip if necessary */
1324	if (ppd->sdma_descq_tail != tail_c) {
1325		ppd->sdma_generation = gen_c;
1326		dd->f_sdma_update_tail(ppd, tail_c);
1327	}
1328
1329	if (nfree && !list_empty(pktlist))
1330		goto retry;
1331}
1332
1333/* pq->lock must be held, get packets on the wire... */
1334static int qib_user_sdma_push_pkts(struct qib_pportdata *ppd,
1335				 struct qib_user_sdma_queue *pq,
1336				 struct list_head *pktlist, int count)
1337{
1338	unsigned long flags;
1339
1340	if (unlikely(!(ppd->lflags & QIBL_LINKACTIVE)))
1341		return -ECOMM;
1342
1343	/* non-blocking mode */
1344	if (pq->sdma_rb_node->refcount > 1) {
1345		spin_lock_irqsave(&ppd->sdma_lock, flags);
1346		if (unlikely(!__qib_sdma_running(ppd))) {
1347			spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1348			return -ECOMM;
1349		}
1350		pq->num_pending += count;
1351		list_splice_tail_init(pktlist, &ppd->sdma_userpending);
1352		qib_user_sdma_send_desc(ppd, &ppd->sdma_userpending);
1353		spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1354		return 0;
1355	}
1356
1357	/* In this case, descriptors from this process are not
1358	 * linked to ppd pending queue, interrupt handler
1359	 * won't update this process, it is OK to directly
1360	 * modify without sdma lock.
1361	 */
1362
1363
1364	pq->num_pending += count;
1365	/*
1366	 * Blocking mode for single rail process, we must
1367	 * release/regain sdma_lock to give other process
1368	 * chance to make progress. This is important for
1369	 * performance.
1370	 */
1371	do {
1372		spin_lock_irqsave(&ppd->sdma_lock, flags);
1373		if (unlikely(!__qib_sdma_running(ppd))) {
1374			spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1375			return -ECOMM;
1376		}
1377		qib_user_sdma_send_desc(ppd, pktlist);
1378		if (!list_empty(pktlist))
1379			qib_sdma_make_progress(ppd);
1380		spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1381	} while (!list_empty(pktlist));
1382
1383	return 0;
1384}
1385
1386int qib_user_sdma_writev(struct qib_ctxtdata *rcd,
1387			 struct qib_user_sdma_queue *pq,
1388			 const struct iovec *iov,
1389			 unsigned long dim)
1390{
1391	struct qib_devdata *dd = rcd->dd;
1392	struct qib_pportdata *ppd = rcd->ppd;
1393	int ret = 0;
1394	struct list_head list;
1395	int npkts = 0;
1396
1397	INIT_LIST_HEAD(&list);
1398
1399	mutex_lock(&pq->lock);
1400
1401	/* why not -ECOMM like qib_user_sdma_push_pkts() below? */
1402	if (!qib_sdma_running(ppd))
1403		goto done_unlock;
1404
1405	/* if I have packets not complete yet */
1406	if (pq->added > ppd->sdma_descq_removed)
1407		qib_user_sdma_hwqueue_clean(ppd);
1408	/* if I have complete packets to be freed */
1409	if (pq->num_sending)
1410		qib_user_sdma_queue_clean(ppd, pq);
1411
1412	while (dim) {
1413		int mxp = 1;
1414		int ndesc = 0;
1415
1416		ret = qib_user_sdma_queue_pkts(dd, ppd, pq,
1417				iov, dim, &list, &mxp, &ndesc);
1418		if (ret < 0)
1419			goto done_unlock;
1420		else {
1421			dim -= ret;
1422			iov += ret;
1423		}
1424
1425		/* force packets onto the sdma hw queue... */
1426		if (!list_empty(&list)) {
1427			/*
1428			 * Lazily clean hw queue.
1429			 */
1430			if (qib_sdma_descq_freecnt(ppd) < ndesc) {
1431				qib_user_sdma_hwqueue_clean(ppd);
1432				if (pq->num_sending)
1433					qib_user_sdma_queue_clean(ppd, pq);
1434			}
1435
1436			ret = qib_user_sdma_push_pkts(ppd, pq, &list, mxp);
1437			if (ret < 0)
1438				goto done_unlock;
1439			else {
1440				npkts += mxp;
1441				pq->counter += mxp;
1442			}
1443		}
1444	}
1445
1446done_unlock:
1447	if (!list_empty(&list))
1448		qib_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &list);
1449	mutex_unlock(&pq->lock);
1450
1451	return (ret < 0) ? ret : npkts;
1452}
1453
1454int qib_user_sdma_make_progress(struct qib_pportdata *ppd,
1455				struct qib_user_sdma_queue *pq)
1456{
1457	int ret = 0;
1458
1459	mutex_lock(&pq->lock);
1460	qib_user_sdma_hwqueue_clean(ppd);
1461	ret = qib_user_sdma_queue_clean(ppd, pq);
1462	mutex_unlock(&pq->lock);
1463
1464	return ret;
1465}
1466
1467u32 qib_user_sdma_complete_counter(const struct qib_user_sdma_queue *pq)
1468{
1469	return pq ? pq->sent_counter : 0;
1470}
1471
1472u32 qib_user_sdma_inflight_counter(struct qib_user_sdma_queue *pq)
1473{
1474	return pq ? pq->counter : 0;
1475}
1476