1/*
2 * Copyright (c) 2007, 2008 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/sched.h>
37#include <linux/slab.h>
38#include <linux/list.h>
39#include <linux/highmem.h>
40#include <linux/io.h>
41#include <linux/uio.h>
42#include <linux/rbtree.h>
43#include <linux/spinlock.h>
44#include <linux/delay.h>
45
46#include "ipath_kernel.h"
47#include "ipath_user_sdma.h"
48
49/* minimum size of header */
50#define IPATH_USER_SDMA_MIN_HEADER_LENGTH	64
51/* expected size of headers (for dma_pool) */
52#define IPATH_USER_SDMA_EXP_HEADER_LENGTH	64
53/* length mask in PBC (lower 11 bits) */
54#define IPATH_PBC_LENGTH_MASK			((1 << 11) - 1)
55
56struct ipath_user_sdma_pkt {
57	u8 naddr;		/* dimension of addr (1..3) ... */
58	u32 counter;		/* sdma pkts queued counter for this entry */
59	u64 added;		/* global descq number of entries */
60
61	struct {
62		u32 offset;			/* offset for kvaddr, addr */
63		u32 length;			/* length in page */
64		u8  put_page;			/* should we put_page? */
65		u8  dma_mapped;			/* is page dma_mapped? */
66		struct page *page;		/* may be NULL (coherent mem) */
67		void *kvaddr;			/* FIXME: only for pio hack */
68		dma_addr_t addr;
69	} addr[4];   /* max pages, any more and we coalesce */
70	struct list_head list;	/* list element */
71};
72
73struct ipath_user_sdma_queue {
74	/*
75	 * pkts sent to dma engine are queued on this
76	 * list head.  the type of the elements of this
77	 * list are struct ipath_user_sdma_pkt...
78	 */
79	struct list_head sent;
80
81	/* headers with expected length are allocated from here... */
82	char header_cache_name[64];
83	struct dma_pool *header_cache;
84
85	/* packets are allocated from the slab cache... */
86	char pkt_slab_name[64];
87	struct kmem_cache *pkt_slab;
88
89	/* as packets go on the queued queue, they are counted... */
90	u32 counter;
91	u32 sent_counter;
92
93	/* dma page table */
94	struct rb_root dma_pages_root;
95
96	/* protect everything above... */
97	struct mutex lock;
98};
99
100struct ipath_user_sdma_queue *
101ipath_user_sdma_queue_create(struct device *dev, int unit, int port, int sport)
102{
103	struct ipath_user_sdma_queue *pq =
104		kmalloc(sizeof(struct ipath_user_sdma_queue), GFP_KERNEL);
105
106	if (!pq)
107		goto done;
108
109	pq->counter = 0;
110	pq->sent_counter = 0;
111	INIT_LIST_HEAD(&pq->sent);
112
113	mutex_init(&pq->lock);
114
115	snprintf(pq->pkt_slab_name, sizeof(pq->pkt_slab_name),
116		 "ipath-user-sdma-pkts-%u-%02u.%02u", unit, port, sport);
117	pq->pkt_slab = kmem_cache_create(pq->pkt_slab_name,
118					 sizeof(struct ipath_user_sdma_pkt),
119					 0, 0, NULL);
120
121	if (!pq->pkt_slab)
122		goto err_kfree;
123
124	snprintf(pq->header_cache_name, sizeof(pq->header_cache_name),
125		 "ipath-user-sdma-headers-%u-%02u.%02u", unit, port, sport);
126	pq->header_cache = dma_pool_create(pq->header_cache_name,
127					   dev,
128					   IPATH_USER_SDMA_EXP_HEADER_LENGTH,
129					   4, 0);
130	if (!pq->header_cache)
131		goto err_slab;
132
133	pq->dma_pages_root = RB_ROOT;
134
135	goto done;
136
137err_slab:
138	kmem_cache_destroy(pq->pkt_slab);
139err_kfree:
140	kfree(pq);
141	pq = NULL;
142
143done:
144	return pq;
145}
146
147static void ipath_user_sdma_init_frag(struct ipath_user_sdma_pkt *pkt,
148				      int i, size_t offset, size_t len,
149				      int put_page, int dma_mapped,
150				      struct page *page,
151				      void *kvaddr, dma_addr_t dma_addr)
152{
153	pkt->addr[i].offset = offset;
154	pkt->addr[i].length = len;
155	pkt->addr[i].put_page = put_page;
156	pkt->addr[i].dma_mapped = dma_mapped;
157	pkt->addr[i].page = page;
158	pkt->addr[i].kvaddr = kvaddr;
159	pkt->addr[i].addr = dma_addr;
160}
161
162static void ipath_user_sdma_init_header(struct ipath_user_sdma_pkt *pkt,
163					u32 counter, size_t offset,
164					size_t len, int dma_mapped,
165					struct page *page,
166					void *kvaddr, dma_addr_t dma_addr)
167{
168	pkt->naddr = 1;
169	pkt->counter = counter;
170	ipath_user_sdma_init_frag(pkt, 0, offset, len, 0, dma_mapped, page,
171				  kvaddr, dma_addr);
172}
173
174/* we've too many pages in the iovec, coalesce to a single page */
175static int ipath_user_sdma_coalesce(const struct ipath_devdata *dd,
176				    struct ipath_user_sdma_pkt *pkt,
177				    const struct iovec *iov,
178				    unsigned long niov) {
179	int ret = 0;
180	struct page *page = alloc_page(GFP_KERNEL);
181	void *mpage_save;
182	char *mpage;
183	int i;
184	int len = 0;
185	dma_addr_t dma_addr;
186
187	if (!page) {
188		ret = -ENOMEM;
189		goto done;
190	}
191
192	mpage = kmap(page);
193	mpage_save = mpage;
194	for (i = 0; i < niov; i++) {
195		int cfur;
196
197		cfur = copy_from_user(mpage,
198				      iov[i].iov_base, iov[i].iov_len);
199		if (cfur) {
200			ret = -EFAULT;
201			goto free_unmap;
202		}
203
204		mpage += iov[i].iov_len;
205		len += iov[i].iov_len;
206	}
207
208	dma_addr = dma_map_page(&dd->pcidev->dev, page, 0, len,
209				DMA_TO_DEVICE);
210	if (dma_mapping_error(&dd->pcidev->dev, dma_addr)) {
211		ret = -ENOMEM;
212		goto free_unmap;
213	}
214
215	ipath_user_sdma_init_frag(pkt, 1, 0, len, 0, 1, page, mpage_save,
216				  dma_addr);
217	pkt->naddr = 2;
218
219	goto done;
220
221free_unmap:
222	kunmap(page);
223	__free_page(page);
224done:
225	return ret;
226}
227
228/* how many pages in this iovec element? */
229static int ipath_user_sdma_num_pages(const struct iovec *iov)
230{
231	const unsigned long addr  = (unsigned long) iov->iov_base;
232	const unsigned long  len  = iov->iov_len;
233	const unsigned long spage = addr & PAGE_MASK;
234	const unsigned long epage = (addr + len - 1) & PAGE_MASK;
235
236	return 1 + ((epage - spage) >> PAGE_SHIFT);
237}
238
239/* truncate length to page boundary */
240static int ipath_user_sdma_page_length(unsigned long addr, unsigned long len)
241{
242	const unsigned long offset = addr & ~PAGE_MASK;
243
244	return ((offset + len) > PAGE_SIZE) ? (PAGE_SIZE - offset) : len;
245}
246
247static void ipath_user_sdma_free_pkt_frag(struct device *dev,
248					  struct ipath_user_sdma_queue *pq,
249					  struct ipath_user_sdma_pkt *pkt,
250					  int frag)
251{
252	const int i = frag;
253
254	if (pkt->addr[i].page) {
255		if (pkt->addr[i].dma_mapped)
256			dma_unmap_page(dev,
257				       pkt->addr[i].addr,
258				       pkt->addr[i].length,
259				       DMA_TO_DEVICE);
260
261		if (pkt->addr[i].kvaddr)
262			kunmap(pkt->addr[i].page);
263
264		if (pkt->addr[i].put_page)
265			put_page(pkt->addr[i].page);
266		else
267			__free_page(pkt->addr[i].page);
268	} else if (pkt->addr[i].kvaddr)
269		/* free coherent mem from cache... */
270		dma_pool_free(pq->header_cache,
271			      pkt->addr[i].kvaddr, pkt->addr[i].addr);
272}
273
274/* return number of pages pinned... */
275static int ipath_user_sdma_pin_pages(const struct ipath_devdata *dd,
276				     struct ipath_user_sdma_pkt *pkt,
277				     unsigned long addr, int tlen, int npages)
278{
279	struct page *pages[2];
280	int j;
281	int ret;
282
283	ret = get_user_pages(current, current->mm, addr,
284			     npages, 0, 1, pages, NULL);
285
286	if (ret != npages) {
287		int i;
288
289		for (i = 0; i < ret; i++)
290			put_page(pages[i]);
291
292		ret = -ENOMEM;
293		goto done;
294	}
295
296	for (j = 0; j < npages; j++) {
297		/* map the pages... */
298		const int flen =
299			ipath_user_sdma_page_length(addr, tlen);
300		dma_addr_t dma_addr =
301			dma_map_page(&dd->pcidev->dev,
302				     pages[j], 0, flen, DMA_TO_DEVICE);
303		unsigned long fofs = addr & ~PAGE_MASK;
304
305		if (dma_mapping_error(&dd->pcidev->dev, dma_addr)) {
306			ret = -ENOMEM;
307			goto done;
308		}
309
310		ipath_user_sdma_init_frag(pkt, pkt->naddr, fofs, flen, 1, 1,
311					  pages[j], kmap(pages[j]),
312					  dma_addr);
313
314		pkt->naddr++;
315		addr += flen;
316		tlen -= flen;
317	}
318
319done:
320	return ret;
321}
322
323static int ipath_user_sdma_pin_pkt(const struct ipath_devdata *dd,
324				   struct ipath_user_sdma_queue *pq,
325				   struct ipath_user_sdma_pkt *pkt,
326				   const struct iovec *iov,
327				   unsigned long niov)
328{
329	int ret = 0;
330	unsigned long idx;
331
332	for (idx = 0; idx < niov; idx++) {
333		const int npages = ipath_user_sdma_num_pages(iov + idx);
334		const unsigned long addr = (unsigned long) iov[idx].iov_base;
335
336		ret = ipath_user_sdma_pin_pages(dd, pkt,
337						addr, iov[idx].iov_len,
338						npages);
339		if (ret < 0)
340			goto free_pkt;
341	}
342
343	goto done;
344
345free_pkt:
346	for (idx = 0; idx < pkt->naddr; idx++)
347		ipath_user_sdma_free_pkt_frag(&dd->pcidev->dev, pq, pkt, idx);
348
349done:
350	return ret;
351}
352
353static int ipath_user_sdma_init_payload(const struct ipath_devdata *dd,
354					struct ipath_user_sdma_queue *pq,
355					struct ipath_user_sdma_pkt *pkt,
356					const struct iovec *iov,
357					unsigned long niov, int npages)
358{
359	int ret = 0;
360
361	if (npages >= ARRAY_SIZE(pkt->addr))
362		ret = ipath_user_sdma_coalesce(dd, pkt, iov, niov);
363	else
364		ret = ipath_user_sdma_pin_pkt(dd, pq, pkt, iov, niov);
365
366	return ret;
367}
368
369/* free a packet list -- return counter value of last packet */
370static void ipath_user_sdma_free_pkt_list(struct device *dev,
371					  struct ipath_user_sdma_queue *pq,
372					  struct list_head *list)
373{
374	struct ipath_user_sdma_pkt *pkt, *pkt_next;
375
376	list_for_each_entry_safe(pkt, pkt_next, list, list) {
377		int i;
378
379		for (i = 0; i < pkt->naddr; i++)
380			ipath_user_sdma_free_pkt_frag(dev, pq, pkt, i);
381
382		kmem_cache_free(pq->pkt_slab, pkt);
383	}
384}
385
386/*
387 * copy headers, coalesce etc -- pq->lock must be held
388 *
389 * we queue all the packets to list, returning the
390 * number of bytes total.  list must be empty initially,
391 * as, if there is an error we clean it...
392 */
393static int ipath_user_sdma_queue_pkts(const struct ipath_devdata *dd,
394				      struct ipath_user_sdma_queue *pq,
395				      struct list_head *list,
396				      const struct iovec *iov,
397				      unsigned long niov,
398				      int maxpkts)
399{
400	unsigned long idx = 0;
401	int ret = 0;
402	int npkts = 0;
403	struct page *page = NULL;
404	__le32 *pbc;
405	dma_addr_t dma_addr;
406	struct ipath_user_sdma_pkt *pkt = NULL;
407	size_t len;
408	size_t nw;
409	u32 counter = pq->counter;
410	int dma_mapped = 0;
411
412	while (idx < niov && npkts < maxpkts) {
413		const unsigned long addr = (unsigned long) iov[idx].iov_base;
414		const unsigned long idx_save = idx;
415		unsigned pktnw;
416		unsigned pktnwc;
417		int nfrags = 0;
418		int npages = 0;
419		int cfur;
420
421		dma_mapped = 0;
422		len = iov[idx].iov_len;
423		nw = len >> 2;
424		page = NULL;
425
426		pkt = kmem_cache_alloc(pq->pkt_slab, GFP_KERNEL);
427		if (!pkt) {
428			ret = -ENOMEM;
429			goto free_list;
430		}
431
432		if (len < IPATH_USER_SDMA_MIN_HEADER_LENGTH ||
433		    len > PAGE_SIZE || len & 3 || addr & 3) {
434			ret = -EINVAL;
435			goto free_pkt;
436		}
437
438		if (len == IPATH_USER_SDMA_EXP_HEADER_LENGTH)
439			pbc = dma_pool_alloc(pq->header_cache, GFP_KERNEL,
440					     &dma_addr);
441		else
442			pbc = NULL;
443
444		if (!pbc) {
445			page = alloc_page(GFP_KERNEL);
446			if (!page) {
447				ret = -ENOMEM;
448				goto free_pkt;
449			}
450			pbc = kmap(page);
451		}
452
453		cfur = copy_from_user(pbc, iov[idx].iov_base, len);
454		if (cfur) {
455			ret = -EFAULT;
456			goto free_pbc;
457		}
458
459		/*
460		 * this assignment is a bit strange.  it's because the
461		 * the pbc counts the number of 32 bit words in the full
462		 * packet _except_ the first word of the pbc itself...
463		 */
464		pktnwc = nw - 1;
465
466		/*
467		 * pktnw computation yields the number of 32 bit words
468		 * that the caller has indicated in the PBC.  note that
469		 * this is one less than the total number of words that
470		 * goes to the send DMA engine as the first 32 bit word
471		 * of the PBC itself is not counted.  Armed with this count,
472		 * we can verify that the packet is consistent with the
473		 * iovec lengths.
474		 */
475		pktnw = le32_to_cpu(*pbc) & IPATH_PBC_LENGTH_MASK;
476		if (pktnw < pktnwc || pktnw > pktnwc + (PAGE_SIZE >> 2)) {
477			ret = -EINVAL;
478			goto free_pbc;
479		}
480
481
482		idx++;
483		while (pktnwc < pktnw && idx < niov) {
484			const size_t slen = iov[idx].iov_len;
485			const unsigned long faddr =
486				(unsigned long) iov[idx].iov_base;
487
488			if (slen & 3 || faddr & 3 || !slen ||
489			    slen > PAGE_SIZE) {
490				ret = -EINVAL;
491				goto free_pbc;
492			}
493
494			npages++;
495			if ((faddr & PAGE_MASK) !=
496			    ((faddr + slen - 1) & PAGE_MASK))
497				npages++;
498
499			pktnwc += slen >> 2;
500			idx++;
501			nfrags++;
502		}
503
504		if (pktnwc != pktnw) {
505			ret = -EINVAL;
506			goto free_pbc;
507		}
508
509		if (page) {
510			dma_addr = dma_map_page(&dd->pcidev->dev,
511						page, 0, len, DMA_TO_DEVICE);
512			if (dma_mapping_error(&dd->pcidev->dev, dma_addr)) {
513				ret = -ENOMEM;
514				goto free_pbc;
515			}
516
517			dma_mapped = 1;
518		}
519
520		ipath_user_sdma_init_header(pkt, counter, 0, len, dma_mapped,
521					    page, pbc, dma_addr);
522
523		if (nfrags) {
524			ret = ipath_user_sdma_init_payload(dd, pq, pkt,
525							   iov + idx_save + 1,
526							   nfrags, npages);
527			if (ret < 0)
528				goto free_pbc_dma;
529		}
530
531		counter++;
532		npkts++;
533
534		list_add_tail(&pkt->list, list);
535	}
536
537	ret = idx;
538	goto done;
539
540free_pbc_dma:
541	if (dma_mapped)
542		dma_unmap_page(&dd->pcidev->dev, dma_addr, len, DMA_TO_DEVICE);
543free_pbc:
544	if (page) {
545		kunmap(page);
546		__free_page(page);
547	} else
548		dma_pool_free(pq->header_cache, pbc, dma_addr);
549free_pkt:
550	kmem_cache_free(pq->pkt_slab, pkt);
551free_list:
552	ipath_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, list);
553done:
554	return ret;
555}
556
557static void ipath_user_sdma_set_complete_counter(struct ipath_user_sdma_queue *pq,
558						 u32 c)
559{
560	pq->sent_counter = c;
561}
562
563/* try to clean out queue -- needs pq->lock */
564static int ipath_user_sdma_queue_clean(const struct ipath_devdata *dd,
565				       struct ipath_user_sdma_queue *pq)
566{
567	struct list_head free_list;
568	struct ipath_user_sdma_pkt *pkt;
569	struct ipath_user_sdma_pkt *pkt_prev;
570	int ret = 0;
571
572	INIT_LIST_HEAD(&free_list);
573
574	list_for_each_entry_safe(pkt, pkt_prev, &pq->sent, list) {
575		s64 descd = dd->ipath_sdma_descq_removed - pkt->added;
576
577		if (descd < 0)
578			break;
579
580		list_move_tail(&pkt->list, &free_list);
581
582		/* one more packet cleaned */
583		ret++;
584	}
585
586	if (!list_empty(&free_list)) {
587		u32 counter;
588
589		pkt = list_entry(free_list.prev,
590				 struct ipath_user_sdma_pkt, list);
591		counter = pkt->counter;
592
593		ipath_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
594		ipath_user_sdma_set_complete_counter(pq, counter);
595	}
596
597	return ret;
598}
599
600void ipath_user_sdma_queue_destroy(struct ipath_user_sdma_queue *pq)
601{
602	if (!pq)
603		return;
604
605	kmem_cache_destroy(pq->pkt_slab);
606	dma_pool_destroy(pq->header_cache);
607	kfree(pq);
608}
609
610/* clean descriptor queue, returns > 0 if some elements cleaned */
611static int ipath_user_sdma_hwqueue_clean(struct ipath_devdata *dd)
612{
613	int ret;
614	unsigned long flags;
615
616	spin_lock_irqsave(&dd->ipath_sdma_lock, flags);
617	ret = ipath_sdma_make_progress(dd);
618	spin_unlock_irqrestore(&dd->ipath_sdma_lock, flags);
619
620	return ret;
621}
622
623/* we're in close, drain packets so that we can cleanup successfully... */
624void ipath_user_sdma_queue_drain(struct ipath_devdata *dd,
625				 struct ipath_user_sdma_queue *pq)
626{
627	int i;
628
629	if (!pq)
630		return;
631
632	for (i = 0; i < 100; i++) {
633		mutex_lock(&pq->lock);
634		if (list_empty(&pq->sent)) {
635			mutex_unlock(&pq->lock);
636			break;
637		}
638		ipath_user_sdma_hwqueue_clean(dd);
639		ipath_user_sdma_queue_clean(dd, pq);
640		mutex_unlock(&pq->lock);
641		msleep(10);
642	}
643
644	if (!list_empty(&pq->sent)) {
645		struct list_head free_list;
646
647		printk(KERN_INFO "drain: lists not empty: forcing!\n");
648		INIT_LIST_HEAD(&free_list);
649		mutex_lock(&pq->lock);
650		list_splice_init(&pq->sent, &free_list);
651		ipath_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
652		mutex_unlock(&pq->lock);
653	}
654}
655
656static inline __le64 ipath_sdma_make_desc0(struct ipath_devdata *dd,
657					   u64 addr, u64 dwlen, u64 dwoffset)
658{
659	return cpu_to_le64(/* SDmaPhyAddr[31:0] */
660			   ((addr & 0xfffffffcULL) << 32) |
661			   /* SDmaGeneration[1:0] */
662			   ((dd->ipath_sdma_generation & 3ULL) << 30) |
663			   /* SDmaDwordCount[10:0] */
664			   ((dwlen & 0x7ffULL) << 16) |
665			   /* SDmaBufOffset[12:2] */
666			   (dwoffset & 0x7ffULL));
667}
668
669static inline __le64 ipath_sdma_make_first_desc0(__le64 descq)
670{
671	return descq | cpu_to_le64(1ULL << 12);
672}
673
674static inline __le64 ipath_sdma_make_last_desc0(__le64 descq)
675{
676					      /* last */  /* dma head */
677	return descq | cpu_to_le64(1ULL << 11 | 1ULL << 13);
678}
679
680static inline __le64 ipath_sdma_make_desc1(u64 addr)
681{
682	/* SDmaPhyAddr[47:32] */
683	return cpu_to_le64(addr >> 32);
684}
685
686static void ipath_user_sdma_send_frag(struct ipath_devdata *dd,
687				      struct ipath_user_sdma_pkt *pkt, int idx,
688				      unsigned ofs, u16 tail)
689{
690	const u64 addr = (u64) pkt->addr[idx].addr +
691		(u64) pkt->addr[idx].offset;
692	const u64 dwlen = (u64) pkt->addr[idx].length / 4;
693	__le64 *descqp;
694	__le64 descq0;
695
696	descqp = &dd->ipath_sdma_descq[tail].qw[0];
697
698	descq0 = ipath_sdma_make_desc0(dd, addr, dwlen, ofs);
699	if (idx == 0)
700		descq0 = ipath_sdma_make_first_desc0(descq0);
701	if (idx == pkt->naddr - 1)
702		descq0 = ipath_sdma_make_last_desc0(descq0);
703
704	descqp[0] = descq0;
705	descqp[1] = ipath_sdma_make_desc1(addr);
706}
707
708/* pq->lock must be held, get packets on the wire... */
709static int ipath_user_sdma_push_pkts(struct ipath_devdata *dd,
710				     struct ipath_user_sdma_queue *pq,
711				     struct list_head *pktlist)
712{
713	int ret = 0;
714	unsigned long flags;
715	u16 tail;
716
717	if (list_empty(pktlist))
718		return 0;
719
720	if (unlikely(!(dd->ipath_flags & IPATH_LINKACTIVE)))
721		return -ECOMM;
722
723	spin_lock_irqsave(&dd->ipath_sdma_lock, flags);
724
725	if (unlikely(dd->ipath_sdma_status & IPATH_SDMA_ABORT_MASK)) {
726		ret = -ECOMM;
727		goto unlock;
728	}
729
730	tail = dd->ipath_sdma_descq_tail;
731	while (!list_empty(pktlist)) {
732		struct ipath_user_sdma_pkt *pkt =
733			list_entry(pktlist->next, struct ipath_user_sdma_pkt,
734				   list);
735		int i;
736		unsigned ofs = 0;
737		u16 dtail = tail;
738
739		if (pkt->naddr > ipath_sdma_descq_freecnt(dd))
740			goto unlock_check_tail;
741
742		for (i = 0; i < pkt->naddr; i++) {
743			ipath_user_sdma_send_frag(dd, pkt, i, ofs, tail);
744			ofs += pkt->addr[i].length >> 2;
745
746			if (++tail == dd->ipath_sdma_descq_cnt) {
747				tail = 0;
748				++dd->ipath_sdma_generation;
749			}
750		}
751
752		if ((ofs<<2) > dd->ipath_ibmaxlen) {
753			ipath_dbg("packet size %X > ibmax %X, fail\n",
754				ofs<<2, dd->ipath_ibmaxlen);
755			ret = -EMSGSIZE;
756			goto unlock;
757		}
758
759		/*
760		 * if the packet is >= 2KB mtu equivalent, we have to use
761		 * the large buffers, and have to mark each descriptor as
762		 * part of a large buffer packet.
763		 */
764		if (ofs >= IPATH_SMALLBUF_DWORDS) {
765			for (i = 0; i < pkt->naddr; i++) {
766				dd->ipath_sdma_descq[dtail].qw[0] |=
767					cpu_to_le64(1ULL << 14);
768				if (++dtail == dd->ipath_sdma_descq_cnt)
769					dtail = 0;
770			}
771		}
772
773		dd->ipath_sdma_descq_added += pkt->naddr;
774		pkt->added = dd->ipath_sdma_descq_added;
775		list_move_tail(&pkt->list, &pq->sent);
776		ret++;
777	}
778
779unlock_check_tail:
780	/* advance the tail on the chip if necessary */
781	if (dd->ipath_sdma_descq_tail != tail) {
782		wmb();
783		ipath_write_kreg(dd, dd->ipath_kregs->kr_senddmatail, tail);
784		dd->ipath_sdma_descq_tail = tail;
785	}
786
787unlock:
788	spin_unlock_irqrestore(&dd->ipath_sdma_lock, flags);
789
790	return ret;
791}
792
793int ipath_user_sdma_writev(struct ipath_devdata *dd,
794			   struct ipath_user_sdma_queue *pq,
795			   const struct iovec *iov,
796			   unsigned long dim)
797{
798	int ret = 0;
799	struct list_head list;
800	int npkts = 0;
801
802	INIT_LIST_HEAD(&list);
803
804	mutex_lock(&pq->lock);
805
806	if (dd->ipath_sdma_descq_added != dd->ipath_sdma_descq_removed) {
807		ipath_user_sdma_hwqueue_clean(dd);
808		ipath_user_sdma_queue_clean(dd, pq);
809	}
810
811	while (dim) {
812		const int mxp = 8;
813
814		down_write(&current->mm->mmap_sem);
815		ret = ipath_user_sdma_queue_pkts(dd, pq, &list, iov, dim, mxp);
816		up_write(&current->mm->mmap_sem);
817
818		if (ret <= 0)
819			goto done_unlock;
820		else {
821			dim -= ret;
822			iov += ret;
823		}
824
825		/* force packets onto the sdma hw queue... */
826		if (!list_empty(&list)) {
827			/*
828			 * lazily clean hw queue.  the 4 is a guess of about
829			 * how many sdma descriptors a packet will take (it
830			 * doesn't have to be perfect).
831			 */
832			if (ipath_sdma_descq_freecnt(dd) < ret * 4) {
833				ipath_user_sdma_hwqueue_clean(dd);
834				ipath_user_sdma_queue_clean(dd, pq);
835			}
836
837			ret = ipath_user_sdma_push_pkts(dd, pq, &list);
838			if (ret < 0)
839				goto done_unlock;
840			else {
841				npkts += ret;
842				pq->counter += ret;
843
844				if (!list_empty(&list))
845					goto done_unlock;
846			}
847		}
848	}
849
850done_unlock:
851	if (!list_empty(&list))
852		ipath_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &list);
853	mutex_unlock(&pq->lock);
854
855	return (ret < 0) ? ret : npkts;
856}
857
858int ipath_user_sdma_make_progress(struct ipath_devdata *dd,
859				  struct ipath_user_sdma_queue *pq)
860{
861	int ret = 0;
862
863	mutex_lock(&pq->lock);
864	ipath_user_sdma_hwqueue_clean(dd);
865	ret = ipath_user_sdma_queue_clean(dd, pq);
866	mutex_unlock(&pq->lock);
867
868	return ret;
869}
870
871u32 ipath_user_sdma_complete_counter(const struct ipath_user_sdma_queue *pq)
872{
873	return pq->sent_counter;
874}
875
876u32 ipath_user_sdma_inflight_counter(struct ipath_user_sdma_queue *pq)
877{
878	return pq->counter;
879}
880
881