xref: /freebsd/sys/dev/cxgbe/tom/t4_ddp.c (revision e05ec081fe81beb79567b82723bd045aa50f19c0)
1 /*-
2  * Copyright (c) 2012 Chelsio Communications, Inc.
3  * All rights reserved.
4  * Written by: Navdeep Parhar <np@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include "opt_inet.h"
32 
33 #include <sys/param.h>
34 #include <sys/aio.h>
35 #include <sys/file.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/ktr.h>
39 #include <sys/module.h>
40 #include <sys/protosw.h>
41 #include <sys/proc.h>
42 #include <sys/domain.h>
43 #include <sys/socket.h>
44 #include <sys/socketvar.h>
45 #include <sys/taskqueue.h>
46 #include <sys/uio.h>
47 #include <netinet/in.h>
48 #include <netinet/in_pcb.h>
49 #include <netinet/ip.h>
50 #include <netinet/tcp_var.h>
51 #define TCPSTATES
52 #include <netinet/tcp_fsm.h>
53 #include <netinet/toecore.h>
54 
55 #include <vm/vm.h>
56 #include <vm/vm_extern.h>
57 #include <vm/vm_param.h>
58 #include <vm/pmap.h>
59 #include <vm/vm_map.h>
60 #include <vm/vm_page.h>
61 #include <vm/vm_object.h>
62 
63 #ifdef TCP_OFFLOAD
64 #include "common/common.h"
65 #include "common/t4_msg.h"
66 #include "common/t4_regs.h"
67 #include "common/t4_tcb.h"
68 #include "tom/t4_tom.h"
69 
70 VNET_DECLARE(int, tcp_do_autorcvbuf);
71 #define V_tcp_do_autorcvbuf VNET(tcp_do_autorcvbuf)
72 VNET_DECLARE(int, tcp_autorcvbuf_inc);
73 #define V_tcp_autorcvbuf_inc VNET(tcp_autorcvbuf_inc)
74 VNET_DECLARE(int, tcp_autorcvbuf_max);
75 #define V_tcp_autorcvbuf_max VNET(tcp_autorcvbuf_max)
76 
77 /*
78  * Use the 'backend3' field in AIO jobs to store the amount of data
79  * received by the AIO job so far.
80  */
81 #define	aio_received	backend3
82 
83 static void aio_ddp_requeue_task(void *context, int pending);
84 static void ddp_complete_all(struct toepcb *toep, int error);
85 static void t4_aio_cancel_active(struct kaiocb *job);
86 static void t4_aio_cancel_queued(struct kaiocb *job);
87 
88 #define PPOD_SZ(n)	((n) * sizeof(struct pagepod))
89 #define PPOD_SIZE	(PPOD_SZ(1))
90 
91 static TAILQ_HEAD(, pageset) ddp_orphan_pagesets;
92 static struct mtx ddp_orphan_pagesets_lock;
93 static struct task ddp_orphan_task;
94 
95 #define MAX_DDP_BUFFER_SIZE		(M_TCB_RX_DDP_BUF0_LEN)
96 static int
97 alloc_ppods(struct tom_data *td, int n, u_int *ppod_addr)
98 {
99 	vmem_addr_t v;
100 	int rc;
101 
102 	MPASS(n > 0);
103 
104 	rc = vmem_alloc(td->ppod_arena, PPOD_SZ(n), M_NOWAIT | M_FIRSTFIT, &v);
105 	*ppod_addr = (u_int)v;
106 
107 	return (rc);
108 }
109 
110 static void
111 free_ppods(struct tom_data *td, u_int ppod_addr, int n)
112 {
113 
114 	MPASS(n > 0);
115 
116 	vmem_free(td->ppod_arena, (vmem_addr_t)ppod_addr, PPOD_SZ(n));
117 }
118 
119 static inline int
120 pages_to_nppods(int npages, int ddp_pgsz)
121 {
122 	int nsegs = npages * PAGE_SIZE / ddp_pgsz;
123 
124 	return (howmany(nsegs, PPOD_PAGES));
125 }
126 
127 /*
128  * A page set holds information about a buffer used for DDP.  The page
129  * set holds resources such as the VM pages backing the buffer (either
130  * held or wired) and the page pods associated with the buffer.
131  * Recently used page sets are cached to allow for efficient reuse of
132  * buffers (avoiding the need to re-fault in pages, hold them, etc.).
133  * Note that cached page sets keep the backing pages wired.  The
134  * number of wired pages is capped by only allowing for two wired
135  * pagesets per connection.  This is not a perfect cap, but is a
136  * trade-off for performance.
137  *
138  * If an application ping-pongs two buffers for a connection via
139  * aio_read(2) then those buffers should remain wired and expensive VM
140  * fault lookups should be avoided after each buffer has been used
141  * once.  If an application uses more than two buffers then this will
142  * fall back to doing expensive VM fault lookups for each operation.
143  */
144 static void
145 free_pageset(struct tom_data *td, struct pageset *ps)
146 {
147 	vm_page_t p;
148 	int i;
149 
150 	if (ps->nppods > 0)
151 		free_ppods(td, ps->ppod_addr, ps->nppods);
152 
153 	if (ps->flags & PS_WIRED) {
154 		for (i = 0; i < ps->npages; i++) {
155 			p = ps->pages[i];
156 			vm_page_lock(p);
157 			vm_page_unwire(p, PQ_INACTIVE);
158 			vm_page_unlock(p);
159 		}
160 	} else
161 		vm_page_unhold_pages(ps->pages, ps->npages);
162 	mtx_lock(&ddp_orphan_pagesets_lock);
163 	TAILQ_INSERT_TAIL(&ddp_orphan_pagesets, ps, link);
164 	taskqueue_enqueue(taskqueue_thread, &ddp_orphan_task);
165 	mtx_unlock(&ddp_orphan_pagesets_lock);
166 }
167 
168 static void
169 ddp_free_orphan_pagesets(void *context, int pending)
170 {
171 	struct pageset *ps;
172 
173 	mtx_lock(&ddp_orphan_pagesets_lock);
174 	while (!TAILQ_EMPTY(&ddp_orphan_pagesets)) {
175 		ps = TAILQ_FIRST(&ddp_orphan_pagesets);
176 		TAILQ_REMOVE(&ddp_orphan_pagesets, ps, link);
177 		mtx_unlock(&ddp_orphan_pagesets_lock);
178 		if (ps->vm)
179 			vmspace_free(ps->vm);
180 		free(ps, M_CXGBE);
181 		mtx_lock(&ddp_orphan_pagesets_lock);
182 	}
183 	mtx_unlock(&ddp_orphan_pagesets_lock);
184 }
185 
186 static void
187 recycle_pageset(struct toepcb *toep, struct pageset *ps)
188 {
189 
190 	DDP_ASSERT_LOCKED(toep);
191 	if (!(toep->ddp_flags & DDP_DEAD) && ps->flags & PS_WIRED) {
192 		KASSERT(toep->ddp_cached_count + toep->ddp_active_count <
193 		    nitems(toep->db), ("too many wired pagesets"));
194 		TAILQ_INSERT_HEAD(&toep->ddp_cached_pagesets, ps, link);
195 		toep->ddp_cached_count++;
196 	} else
197 		free_pageset(toep->td, ps);
198 }
199 
200 static void
201 ddp_complete_one(struct kaiocb *job, int error)
202 {
203 	long copied;
204 
205 	/*
206 	 * If this job had copied data out of the socket buffer before
207 	 * it was cancelled, report it as a short read rather than an
208 	 * error.
209 	 */
210 	copied = job->aio_received;
211 	if (copied != 0 || error == 0)
212 		aio_complete(job, copied, 0);
213 	else
214 		aio_complete(job, -1, error);
215 }
216 
217 static void
218 free_ddp_buffer(struct tom_data *td, struct ddp_buffer *db)
219 {
220 
221 	if (db->job) {
222 		/*
223 		 * XXX: If we are un-offloading the socket then we
224 		 * should requeue these on the socket somehow.  If we
225 		 * got a FIN from the remote end, then this completes
226 		 * any remaining requests with an EOF read.
227 		 */
228 		if (!aio_clear_cancel_function(db->job))
229 			ddp_complete_one(db->job, 0);
230 	}
231 
232 	if (db->ps)
233 		free_pageset(td, db->ps);
234 }
235 
236 void
237 ddp_init_toep(struct toepcb *toep)
238 {
239 
240 	TAILQ_INIT(&toep->ddp_aiojobq);
241 	TASK_INIT(&toep->ddp_requeue_task, 0, aio_ddp_requeue_task, toep);
242 	toep->ddp_active_id = -1;
243 	mtx_init(&toep->ddp_lock, "t4 ddp", NULL, MTX_DEF);
244 }
245 
246 void
247 ddp_uninit_toep(struct toepcb *toep)
248 {
249 
250 	mtx_destroy(&toep->ddp_lock);
251 }
252 
253 void
254 release_ddp_resources(struct toepcb *toep)
255 {
256 	struct pageset *ps;
257 	int i;
258 
259 	DDP_LOCK(toep);
260 	toep->flags |= DDP_DEAD;
261 	for (i = 0; i < nitems(toep->db); i++) {
262 		free_ddp_buffer(toep->td, &toep->db[i]);
263 	}
264 	while ((ps = TAILQ_FIRST(&toep->ddp_cached_pagesets)) != NULL) {
265 		TAILQ_REMOVE(&toep->ddp_cached_pagesets, ps, link);
266 		free_pageset(toep->td, ps);
267 	}
268 	ddp_complete_all(toep, 0);
269 	DDP_UNLOCK(toep);
270 }
271 
272 #ifdef INVARIANTS
273 void
274 ddp_assert_empty(struct toepcb *toep)
275 {
276 	int i;
277 
278 	MPASS(!(toep->ddp_flags & DDP_TASK_ACTIVE));
279 	for (i = 0; i < nitems(toep->db); i++) {
280 		MPASS(toep->db[i].job == NULL);
281 		MPASS(toep->db[i].ps == NULL);
282 	}
283 	MPASS(TAILQ_EMPTY(&toep->ddp_cached_pagesets));
284 	MPASS(TAILQ_EMPTY(&toep->ddp_aiojobq));
285 }
286 #endif
287 
288 static void
289 complete_ddp_buffer(struct toepcb *toep, struct ddp_buffer *db,
290     unsigned int db_idx)
291 {
292 	unsigned int db_flag;
293 
294 	toep->ddp_active_count--;
295 	if (toep->ddp_active_id == db_idx) {
296 		if (toep->ddp_active_count == 0) {
297 			KASSERT(toep->db[db_idx ^ 1].job == NULL,
298 			    ("%s: active_count mismatch", __func__));
299 			toep->ddp_active_id = -1;
300 		} else
301 			toep->ddp_active_id ^= 1;
302 #ifdef VERBOSE_TRACES
303 		CTR2(KTR_CXGBE, "%s: ddp_active_id = %d", __func__,
304 		    toep->ddp_active_id);
305 #endif
306 	} else {
307 		KASSERT(toep->ddp_active_count != 0 &&
308 		    toep->ddp_active_id != -1,
309 		    ("%s: active count mismatch", __func__));
310 	}
311 
312 	db->cancel_pending = 0;
313 	db->job = NULL;
314 	recycle_pageset(toep, db->ps);
315 	db->ps = NULL;
316 
317 	db_flag = db_idx == 1 ? DDP_BUF1_ACTIVE : DDP_BUF0_ACTIVE;
318 	KASSERT(toep->ddp_flags & db_flag,
319 	    ("%s: DDP buffer not active. toep %p, ddp_flags 0x%x",
320 	    __func__, toep, toep->ddp_flags));
321 	toep->ddp_flags &= ~db_flag;
322 }
323 
324 /* XXX: handle_ddp_data code duplication */
325 void
326 insert_ddp_data(struct toepcb *toep, uint32_t n)
327 {
328 	struct inpcb *inp = toep->inp;
329 	struct tcpcb *tp = intotcpcb(inp);
330 	struct ddp_buffer *db;
331 	struct kaiocb *job;
332 	size_t placed;
333 	long copied;
334 	unsigned int db_flag, db_idx;
335 
336 	INP_WLOCK_ASSERT(inp);
337 	DDP_ASSERT_LOCKED(toep);
338 
339 	tp->rcv_nxt += n;
340 #ifndef USE_DDP_RX_FLOW_CONTROL
341 	KASSERT(tp->rcv_wnd >= n, ("%s: negative window size", __func__));
342 	tp->rcv_wnd -= n;
343 #endif
344 #ifndef USE_DDP_RX_FLOW_CONTROL
345 	toep->rx_credits += n;
346 #endif
347 	CTR2(KTR_CXGBE, "%s: placed %u bytes before falling out of DDP",
348 	    __func__, n);
349 	while (toep->ddp_active_count > 0) {
350 		MPASS(toep->ddp_active_id != -1);
351 		db_idx = toep->ddp_active_id;
352 		db_flag = db_idx == 1 ? DDP_BUF1_ACTIVE : DDP_BUF0_ACTIVE;
353 		MPASS((toep->ddp_flags & db_flag) != 0);
354 		db = &toep->db[db_idx];
355 		job = db->job;
356 		copied = job->aio_received;
357 		placed = n;
358 		if (placed > job->uaiocb.aio_nbytes - copied)
359 			placed = job->uaiocb.aio_nbytes - copied;
360 		if (placed > 0)
361 			job->msgrcv = 1;
362 		if (!aio_clear_cancel_function(job)) {
363 			/*
364 			 * Update the copied length for when
365 			 * t4_aio_cancel_active() completes this
366 			 * request.
367 			 */
368 			job->aio_received += placed;
369 		} else if (copied + placed != 0) {
370 			CTR4(KTR_CXGBE,
371 			    "%s: completing %p (copied %ld, placed %lu)",
372 			    __func__, job, copied, placed);
373 			/* XXX: This always completes if there is some data. */
374 			aio_complete(job, copied + placed, 0);
375 		} else if (aio_set_cancel_function(job, t4_aio_cancel_queued)) {
376 			TAILQ_INSERT_HEAD(&toep->ddp_aiojobq, job, list);
377 			toep->ddp_waiting_count++;
378 		} else
379 			aio_cancel(job);
380 		n -= placed;
381 		complete_ddp_buffer(toep, db, db_idx);
382 	}
383 
384 	MPASS(n == 0);
385 }
386 
387 /* SET_TCB_FIELD sent as a ULP command looks like this */
388 #define LEN__SET_TCB_FIELD_ULP (sizeof(struct ulp_txpkt) + \
389     sizeof(struct ulptx_idata) + sizeof(struct cpl_set_tcb_field_core))
390 
391 /* RX_DATA_ACK sent as a ULP command looks like this */
392 #define LEN__RX_DATA_ACK_ULP (sizeof(struct ulp_txpkt) + \
393     sizeof(struct ulptx_idata) + sizeof(struct cpl_rx_data_ack_core))
394 
395 static inline void *
396 mk_set_tcb_field_ulp(struct ulp_txpkt *ulpmc, struct toepcb *toep,
397     uint64_t word, uint64_t mask, uint64_t val)
398 {
399 	struct ulptx_idata *ulpsc;
400 	struct cpl_set_tcb_field_core *req;
401 
402 	ulpmc->cmd_dest = htonl(V_ULPTX_CMD(ULP_TX_PKT) | V_ULP_TXPKT_DEST(0));
403 	ulpmc->len = htobe32(howmany(LEN__SET_TCB_FIELD_ULP, 16));
404 
405 	ulpsc = (struct ulptx_idata *)(ulpmc + 1);
406 	ulpsc->cmd_more = htobe32(V_ULPTX_CMD(ULP_TX_SC_IMM));
407 	ulpsc->len = htobe32(sizeof(*req));
408 
409 	req = (struct cpl_set_tcb_field_core *)(ulpsc + 1);
410 	OPCODE_TID(req) = htobe32(MK_OPCODE_TID(CPL_SET_TCB_FIELD, toep->tid));
411 	req->reply_ctrl = htobe16(V_NO_REPLY(1) |
412 	    V_QUEUENO(toep->ofld_rxq->iq.abs_id));
413 	req->word_cookie = htobe16(V_WORD(word) | V_COOKIE(0));
414         req->mask = htobe64(mask);
415         req->val = htobe64(val);
416 
417 	ulpsc = (struct ulptx_idata *)(req + 1);
418 	if (LEN__SET_TCB_FIELD_ULP % 16) {
419 		ulpsc->cmd_more = htobe32(V_ULPTX_CMD(ULP_TX_SC_NOOP));
420 		ulpsc->len = htobe32(0);
421 		return (ulpsc + 1);
422 	}
423 	return (ulpsc);
424 }
425 
426 static inline void *
427 mk_rx_data_ack_ulp(struct ulp_txpkt *ulpmc, struct toepcb *toep)
428 {
429 	struct ulptx_idata *ulpsc;
430 	struct cpl_rx_data_ack_core *req;
431 
432 	ulpmc->cmd_dest = htonl(V_ULPTX_CMD(ULP_TX_PKT) | V_ULP_TXPKT_DEST(0));
433 	ulpmc->len = htobe32(howmany(LEN__RX_DATA_ACK_ULP, 16));
434 
435 	ulpsc = (struct ulptx_idata *)(ulpmc + 1);
436 	ulpsc->cmd_more = htobe32(V_ULPTX_CMD(ULP_TX_SC_IMM));
437 	ulpsc->len = htobe32(sizeof(*req));
438 
439 	req = (struct cpl_rx_data_ack_core *)(ulpsc + 1);
440 	OPCODE_TID(req) = htobe32(MK_OPCODE_TID(CPL_RX_DATA_ACK, toep->tid));
441 	req->credit_dack = htobe32(F_RX_MODULATE_RX);
442 
443 	ulpsc = (struct ulptx_idata *)(req + 1);
444 	if (LEN__RX_DATA_ACK_ULP % 16) {
445 		ulpsc->cmd_more = htobe32(V_ULPTX_CMD(ULP_TX_SC_NOOP));
446 		ulpsc->len = htobe32(0);
447 		return (ulpsc + 1);
448 	}
449 	return (ulpsc);
450 }
451 
452 static struct wrqe *
453 mk_update_tcb_for_ddp(struct adapter *sc, struct toepcb *toep, int db_idx,
454     struct pageset *ps, int offset, uint64_t ddp_flags, uint64_t ddp_flags_mask)
455 {
456 	struct wrqe *wr;
457 	struct work_request_hdr *wrh;
458 	struct ulp_txpkt *ulpmc;
459 	int len;
460 
461 	KASSERT(db_idx == 0 || db_idx == 1,
462 	    ("%s: bad DDP buffer index %d", __func__, db_idx));
463 
464 	/*
465 	 * We'll send a compound work request that has 3 SET_TCB_FIELDs and an
466 	 * RX_DATA_ACK (with RX_MODULATE to speed up delivery).
467 	 *
468 	 * The work request header is 16B and always ends at a 16B boundary.
469 	 * The ULPTX master commands that follow must all end at 16B boundaries
470 	 * too so we round up the size to 16.
471 	 */
472 	len = sizeof(*wrh) + 3 * roundup2(LEN__SET_TCB_FIELD_ULP, 16) +
473 	    roundup2(LEN__RX_DATA_ACK_ULP, 16);
474 
475 	wr = alloc_wrqe(len, toep->ctrlq);
476 	if (wr == NULL)
477 		return (NULL);
478 	wrh = wrtod(wr);
479 	INIT_ULPTX_WRH(wrh, len, 1, 0);	/* atomic */
480 	ulpmc = (struct ulp_txpkt *)(wrh + 1);
481 
482 	/* Write the buffer's tag */
483 	ulpmc = mk_set_tcb_field_ulp(ulpmc, toep,
484 	    W_TCB_RX_DDP_BUF0_TAG + db_idx,
485 	    V_TCB_RX_DDP_BUF0_TAG(M_TCB_RX_DDP_BUF0_TAG),
486 	    V_TCB_RX_DDP_BUF0_TAG(ps->tag));
487 
488 	/* Update the current offset in the DDP buffer and its total length */
489 	if (db_idx == 0)
490 		ulpmc = mk_set_tcb_field_ulp(ulpmc, toep,
491 		    W_TCB_RX_DDP_BUF0_OFFSET,
492 		    V_TCB_RX_DDP_BUF0_OFFSET(M_TCB_RX_DDP_BUF0_OFFSET) |
493 		    V_TCB_RX_DDP_BUF0_LEN(M_TCB_RX_DDP_BUF0_LEN),
494 		    V_TCB_RX_DDP_BUF0_OFFSET(offset) |
495 		    V_TCB_RX_DDP_BUF0_LEN(ps->len));
496 	else
497 		ulpmc = mk_set_tcb_field_ulp(ulpmc, toep,
498 		    W_TCB_RX_DDP_BUF1_OFFSET,
499 		    V_TCB_RX_DDP_BUF1_OFFSET(M_TCB_RX_DDP_BUF1_OFFSET) |
500 		    V_TCB_RX_DDP_BUF1_LEN((u64)M_TCB_RX_DDP_BUF1_LEN << 32),
501 		    V_TCB_RX_DDP_BUF1_OFFSET(offset) |
502 		    V_TCB_RX_DDP_BUF1_LEN((u64)ps->len << 32));
503 
504 	/* Update DDP flags */
505 	ulpmc = mk_set_tcb_field_ulp(ulpmc, toep, W_TCB_RX_DDP_FLAGS,
506 	    ddp_flags_mask, ddp_flags);
507 
508 	/* Gratuitous RX_DATA_ACK with RX_MODULATE set to speed up delivery. */
509 	ulpmc = mk_rx_data_ack_ulp(ulpmc, toep);
510 
511 	return (wr);
512 }
513 
514 static int
515 handle_ddp_data(struct toepcb *toep, __be32 ddp_report, __be32 rcv_nxt, int len)
516 {
517 	uint32_t report = be32toh(ddp_report);
518 	unsigned int db_idx;
519 	struct inpcb *inp = toep->inp;
520 	struct ddp_buffer *db;
521 	struct tcpcb *tp;
522 	struct socket *so;
523 	struct sockbuf *sb;
524 	struct kaiocb *job;
525 	long copied;
526 
527 	db_idx = report & F_DDP_BUF_IDX ? 1 : 0;
528 
529 	if (__predict_false(!(report & F_DDP_INV)))
530 		CXGBE_UNIMPLEMENTED("DDP buffer still valid");
531 
532 	INP_WLOCK(inp);
533 	so = inp_inpcbtosocket(inp);
534 	sb = &so->so_rcv;
535 	DDP_LOCK(toep);
536 
537 	KASSERT(toep->ddp_active_id == db_idx,
538 	    ("completed DDP buffer (%d) != active_id (%d) for tid %d", db_idx,
539 	    toep->ddp_active_id, toep->tid));
540 	db = &toep->db[db_idx];
541 	job = db->job;
542 
543 	if (__predict_false(inp->inp_flags & (INP_DROPPED | INP_TIMEWAIT))) {
544 		/*
545 		 * This can happen due to an administrative tcpdrop(8).
546 		 * Just fail the request with ECONNRESET.
547 		 */
548 		CTR5(KTR_CXGBE, "%s: tid %u, seq 0x%x, len %d, inp_flags 0x%x",
549 		    __func__, toep->tid, be32toh(rcv_nxt), len, inp->inp_flags);
550 		if (aio_clear_cancel_function(job))
551 			ddp_complete_one(job, ECONNRESET);
552 		goto completed;
553 	}
554 
555 	tp = intotcpcb(inp);
556 
557 	/*
558 	 * For RX_DDP_COMPLETE, len will be zero and rcv_nxt is the
559 	 * sequence number of the next byte to receive.  The length of
560 	 * the data received for this message must be computed by
561 	 * comparing the new and old values of rcv_nxt.
562 	 *
563 	 * For RX_DATA_DDP, len might be non-zero, but it is only the
564 	 * length of the most recent DMA.  It does not include the
565 	 * total length of the data received since the previous update
566 	 * for this DDP buffer.  rcv_nxt is the sequence number of the
567 	 * first received byte from the most recent DMA.
568 	 */
569 	len += be32toh(rcv_nxt) - tp->rcv_nxt;
570 	tp->rcv_nxt += len;
571 	tp->t_rcvtime = ticks;
572 #ifndef USE_DDP_RX_FLOW_CONTROL
573 	KASSERT(tp->rcv_wnd >= len, ("%s: negative window size", __func__));
574 	tp->rcv_wnd -= len;
575 #endif
576 #ifdef VERBOSE_TRACES
577 	CTR4(KTR_CXGBE, "%s: DDP[%d] placed %d bytes (%#x)", __func__, db_idx,
578 	    len, report);
579 #endif
580 
581 	/* receive buffer autosize */
582 	CURVNET_SET(so->so_vnet);
583 	SOCKBUF_LOCK(sb);
584 	if (sb->sb_flags & SB_AUTOSIZE &&
585 	    V_tcp_do_autorcvbuf &&
586 	    sb->sb_hiwat < V_tcp_autorcvbuf_max &&
587 	    len > (sbspace(sb) / 8 * 7)) {
588 		unsigned int hiwat = sb->sb_hiwat;
589 		unsigned int newsize = min(hiwat + V_tcp_autorcvbuf_inc,
590 		    V_tcp_autorcvbuf_max);
591 
592 		if (!sbreserve_locked(sb, newsize, so, NULL))
593 			sb->sb_flags &= ~SB_AUTOSIZE;
594 		else
595 			toep->rx_credits += newsize - hiwat;
596 	}
597 	SOCKBUF_UNLOCK(sb);
598 	CURVNET_RESTORE();
599 
600 #ifndef USE_DDP_RX_FLOW_CONTROL
601 	toep->rx_credits += len;
602 #endif
603 
604 	job->msgrcv = 1;
605 	if (db->cancel_pending) {
606 		/*
607 		 * Update the job's length but defer completion to the
608 		 * TCB_RPL callback.
609 		 */
610 		job->aio_received += len;
611 		goto out;
612 	} else if (!aio_clear_cancel_function(job)) {
613 		/*
614 		 * Update the copied length for when
615 		 * t4_aio_cancel_active() completes this request.
616 		 */
617 		job->aio_received += len;
618 	} else {
619 		copied = job->aio_received;
620 #ifdef VERBOSE_TRACES
621 		CTR4(KTR_CXGBE, "%s: completing %p (copied %ld, placed %d)",
622 		    __func__, job, copied, len);
623 #endif
624 		aio_complete(job, copied + len, 0);
625 		t4_rcvd(&toep->td->tod, tp);
626 	}
627 
628 completed:
629 	complete_ddp_buffer(toep, db, db_idx);
630 	if (toep->ddp_waiting_count > 0)
631 		ddp_queue_toep(toep);
632 out:
633 	DDP_UNLOCK(toep);
634 	INP_WUNLOCK(inp);
635 
636 	return (0);
637 }
638 
639 void
640 handle_ddp_indicate(struct toepcb *toep)
641 {
642 
643 	DDP_ASSERT_LOCKED(toep);
644 	MPASS(toep->ddp_active_count == 0);
645 	MPASS((toep->ddp_flags & (DDP_BUF0_ACTIVE | DDP_BUF1_ACTIVE)) == 0);
646 	if (toep->ddp_waiting_count == 0) {
647 		/*
648 		 * The pending requests that triggered the request for an
649 		 * an indicate were cancelled.  Those cancels should have
650 		 * already disabled DDP.  Just ignore this as the data is
651 		 * going into the socket buffer anyway.
652 		 */
653 		return;
654 	}
655 	CTR3(KTR_CXGBE, "%s: tid %d indicated (%d waiting)", __func__,
656 	    toep->tid, toep->ddp_waiting_count);
657 	ddp_queue_toep(toep);
658 }
659 
660 enum {
661 	DDP_BUF0_INVALIDATED = 0x2,
662 	DDP_BUF1_INVALIDATED
663 };
664 
665 void
666 handle_ddp_tcb_rpl(struct toepcb *toep, const struct cpl_set_tcb_rpl *cpl)
667 {
668 	unsigned int db_idx;
669 	struct inpcb *inp = toep->inp;
670 	struct ddp_buffer *db;
671 	struct kaiocb *job;
672 	long copied;
673 
674 	if (cpl->status != CPL_ERR_NONE)
675 		panic("XXX: tcp_rpl failed: %d", cpl->status);
676 
677 	switch (cpl->cookie) {
678 	case V_WORD(W_TCB_RX_DDP_FLAGS) | V_COOKIE(DDP_BUF0_INVALIDATED):
679 	case V_WORD(W_TCB_RX_DDP_FLAGS) | V_COOKIE(DDP_BUF1_INVALIDATED):
680 		/*
681 		 * XXX: This duplicates a lot of code with handle_ddp_data().
682 		 */
683 		db_idx = G_COOKIE(cpl->cookie) - DDP_BUF0_INVALIDATED;
684 		INP_WLOCK(inp);
685 		DDP_LOCK(toep);
686 		db = &toep->db[db_idx];
687 
688 		/*
689 		 * handle_ddp_data() should leave the job around until
690 		 * this callback runs once a cancel is pending.
691 		 */
692 		MPASS(db != NULL);
693 		MPASS(db->job != NULL);
694 		MPASS(db->cancel_pending);
695 
696 		/*
697 		 * XXX: It's not clear what happens if there is data
698 		 * placed when the buffer is invalidated.  I suspect we
699 		 * need to read the TCB to see how much data was placed.
700 		 *
701 		 * For now this just pretends like nothing was placed.
702 		 *
703 		 * XXX: Note that if we did check the PCB we would need to
704 		 * also take care of updating the tp, etc.
705 		 */
706 		job = db->job;
707 		copied = job->aio_received;
708 		if (copied == 0) {
709 			CTR2(KTR_CXGBE, "%s: cancelling %p", __func__, job);
710 			aio_cancel(job);
711 		} else {
712 			CTR3(KTR_CXGBE, "%s: completing %p (copied %ld)",
713 			    __func__, job, copied);
714 			aio_complete(job, copied, 0);
715 			t4_rcvd(&toep->td->tod, intotcpcb(inp));
716 		}
717 
718 		complete_ddp_buffer(toep, db, db_idx);
719 		if (toep->ddp_waiting_count > 0)
720 			ddp_queue_toep(toep);
721 		DDP_UNLOCK(toep);
722 		INP_WUNLOCK(inp);
723 		break;
724 	default:
725 		panic("XXX: unknown tcb_rpl offset %#x, cookie %#x",
726 		    G_WORD(cpl->cookie), G_COOKIE(cpl->cookie));
727 	}
728 }
729 
730 void
731 handle_ddp_close(struct toepcb *toep, struct tcpcb *tp, __be32 rcv_nxt)
732 {
733 	struct ddp_buffer *db;
734 	struct kaiocb *job;
735 	long copied;
736 	unsigned int db_flag, db_idx;
737 	int len, placed;
738 
739 	INP_WLOCK_ASSERT(toep->inp);
740 	DDP_ASSERT_LOCKED(toep);
741 	len = be32toh(rcv_nxt) - tp->rcv_nxt;
742 
743 	tp->rcv_nxt += len;
744 #ifndef USE_DDP_RX_FLOW_CONTROL
745 	toep->rx_credits += len;
746 #endif
747 
748 	while (toep->ddp_active_count > 0) {
749 		MPASS(toep->ddp_active_id != -1);
750 		db_idx = toep->ddp_active_id;
751 		db_flag = db_idx == 1 ? DDP_BUF1_ACTIVE : DDP_BUF0_ACTIVE;
752 		MPASS((toep->ddp_flags & db_flag) != 0);
753 		db = &toep->db[db_idx];
754 		job = db->job;
755 		copied = job->aio_received;
756 		placed = len;
757 		if (placed > job->uaiocb.aio_nbytes - copied)
758 			placed = job->uaiocb.aio_nbytes - copied;
759 		if (placed > 0)
760 			job->msgrcv = 1;
761 		if (!aio_clear_cancel_function(job)) {
762 			/*
763 			 * Update the copied length for when
764 			 * t4_aio_cancel_active() completes this
765 			 * request.
766 			 */
767 			job->aio_received += placed;
768 		} else {
769 			CTR4(KTR_CXGBE, "%s: tid %d completed buf %d len %d",
770 			    __func__, toep->tid, db_idx, placed);
771 			aio_complete(job, copied + placed, 0);
772 		}
773 		len -= placed;
774 		complete_ddp_buffer(toep, db, db_idx);
775 	}
776 
777 	MPASS(len == 0);
778 	ddp_complete_all(toep, 0);
779 }
780 
781 #define DDP_ERR (F_DDP_PPOD_MISMATCH | F_DDP_LLIMIT_ERR | F_DDP_ULIMIT_ERR |\
782 	 F_DDP_PPOD_PARITY_ERR | F_DDP_PADDING_ERR | F_DDP_OFFSET_ERR |\
783 	 F_DDP_INVALID_TAG | F_DDP_COLOR_ERR | F_DDP_TID_MISMATCH |\
784 	 F_DDP_INVALID_PPOD | F_DDP_HDRCRC_ERR | F_DDP_DATACRC_ERR)
785 
786 extern cpl_handler_t t4_cpl_handler[];
787 
788 static int
789 do_rx_data_ddp(struct sge_iq *iq, const struct rss_header *rss, struct mbuf *m)
790 {
791 	struct adapter *sc = iq->adapter;
792 	const struct cpl_rx_data_ddp *cpl = (const void *)(rss + 1);
793 	unsigned int tid = GET_TID(cpl);
794 	uint32_t vld;
795 	struct toepcb *toep = lookup_tid(sc, tid);
796 
797 	KASSERT(m == NULL, ("%s: wasn't expecting payload", __func__));
798 	KASSERT(toep->tid == tid, ("%s: toep tid/atid mismatch", __func__));
799 	KASSERT(!(toep->flags & TPF_SYNQE),
800 	    ("%s: toep %p claims to be a synq entry", __func__, toep));
801 
802 	vld = be32toh(cpl->ddpvld);
803 	if (__predict_false(vld & DDP_ERR)) {
804 		panic("%s: DDP error 0x%x (tid %d, toep %p)",
805 		    __func__, vld, tid, toep);
806 	}
807 
808 	if (toep->ulp_mode == ULP_MODE_ISCSI) {
809 		t4_cpl_handler[CPL_RX_ISCSI_DDP](iq, rss, m);
810 		return (0);
811 	}
812 
813 	handle_ddp_data(toep, cpl->u.ddp_report, cpl->seq, be16toh(cpl->len));
814 
815 	return (0);
816 }
817 
818 static int
819 do_rx_ddp_complete(struct sge_iq *iq, const struct rss_header *rss,
820     struct mbuf *m)
821 {
822 	struct adapter *sc = iq->adapter;
823 	const struct cpl_rx_ddp_complete *cpl = (const void *)(rss + 1);
824 	unsigned int tid = GET_TID(cpl);
825 	struct toepcb *toep = lookup_tid(sc, tid);
826 
827 	KASSERT(m == NULL, ("%s: wasn't expecting payload", __func__));
828 	KASSERT(toep->tid == tid, ("%s: toep tid/atid mismatch", __func__));
829 	KASSERT(!(toep->flags & TPF_SYNQE),
830 	    ("%s: toep %p claims to be a synq entry", __func__, toep));
831 
832 	handle_ddp_data(toep, cpl->ddp_report, cpl->rcv_nxt, 0);
833 
834 	return (0);
835 }
836 
837 static void
838 enable_ddp(struct adapter *sc, struct toepcb *toep)
839 {
840 
841 	KASSERT((toep->ddp_flags & (DDP_ON | DDP_OK | DDP_SC_REQ)) == DDP_OK,
842 	    ("%s: toep %p has bad ddp_flags 0x%x",
843 	    __func__, toep, toep->ddp_flags));
844 
845 	CTR3(KTR_CXGBE, "%s: tid %u (time %u)",
846 	    __func__, toep->tid, time_uptime);
847 
848 	DDP_ASSERT_LOCKED(toep);
849 	toep->ddp_flags |= DDP_SC_REQ;
850 	t4_set_tcb_field(sc, toep->ctrlq, toep->tid, W_TCB_RX_DDP_FLAGS,
851 	    V_TF_DDP_OFF(1) | V_TF_DDP_INDICATE_OUT(1) |
852 	    V_TF_DDP_BUF0_INDICATE(1) | V_TF_DDP_BUF1_INDICATE(1) |
853 	    V_TF_DDP_BUF0_VALID(1) | V_TF_DDP_BUF1_VALID(1),
854 	    V_TF_DDP_BUF0_INDICATE(1) | V_TF_DDP_BUF1_INDICATE(1), 0, 0,
855 	    toep->ofld_rxq->iq.abs_id);
856 	t4_set_tcb_field(sc, toep->ctrlq, toep->tid, W_TCB_T_FLAGS,
857 	    V_TF_RCV_COALESCE_ENABLE(1), 0, 0, 0, toep->ofld_rxq->iq.abs_id);
858 }
859 
860 static int
861 calculate_hcf(int n1, int n2)
862 {
863 	int a, b, t;
864 
865 	if (n1 <= n2) {
866 		a = n1;
867 		b = n2;
868 	} else {
869 		a = n2;
870 		b = n1;
871 	}
872 
873 	while (a != 0) {
874 		t = a;
875 		a = b % a;
876 		b = t;
877 	}
878 
879 	return (b);
880 }
881 
882 static int
883 alloc_page_pods(struct tom_data *td, struct pageset *ps)
884 {
885 	int i, hcf, seglen, idx, ppod, nppods;
886 	u_int ppod_addr;
887 
888 	KASSERT(ps->nppods == 0, ("%s: page pods already allocated", __func__));
889 
890 	/*
891 	 * The DDP page size is unrelated to the VM page size.  We combine
892 	 * contiguous physical pages into larger segments to get the best DDP
893 	 * page size possible.  This is the largest of the four sizes in
894 	 * A_ULP_RX_TDDP_PSZ that evenly divides the HCF of the segment sizes in
895 	 * the page list.
896 	 */
897 	hcf = 0;
898 	for (i = 0; i < ps->npages; i++) {
899 		seglen = PAGE_SIZE;
900 		while (i < ps->npages - 1 &&
901 		    ps->pages[i]->phys_addr + PAGE_SIZE ==
902 		    ps->pages[i + 1]->phys_addr) {
903 			seglen += PAGE_SIZE;
904 			i++;
905 		}
906 
907 		hcf = calculate_hcf(hcf, seglen);
908 		if (hcf < td->ddp_pgsz[1]) {
909 			idx = 0;
910 			goto have_pgsz;	/* give up, short circuit */
911 		}
912 	}
913 
914 	if (hcf % td->ddp_pgsz[0] != 0) {
915 		/* hmmm.  This could only happen when PAGE_SIZE < 4K */
916 		KASSERT(PAGE_SIZE < 4096,
917 		    ("%s: PAGE_SIZE %d, hcf %d", __func__, PAGE_SIZE, hcf));
918 		CTR3(KTR_CXGBE, "%s: PAGE_SIZE %d, hcf %d",
919 		    __func__, PAGE_SIZE, hcf);
920 		return (0);
921 	}
922 
923 	for (idx = nitems(td->ddp_pgsz) - 1; idx > 0; idx--) {
924 		if (hcf % td->ddp_pgsz[idx] == 0)
925 			break;
926 	}
927 have_pgsz:
928 	MPASS(idx <= M_PPOD_PGSZ);
929 
930 	nppods = pages_to_nppods(ps->npages, td->ddp_pgsz[idx]);
931 	if (alloc_ppods(td, nppods, &ppod_addr) != 0) {
932 		CTR4(KTR_CXGBE, "%s: no pods, nppods %d, npages %d, pgsz %d",
933 		    __func__, nppods, ps->npages, td->ddp_pgsz[idx]);
934 		return (0);
935 	}
936 
937 	ppod = (ppod_addr - td->ppod_start) / PPOD_SIZE;
938 	ps->tag = V_PPOD_PGSZ(idx) | V_PPOD_TAG(ppod);
939 	ps->ppod_addr = ppod_addr;
940 	ps->nppods = nppods;
941 
942 	CTR5(KTR_CXGBE, "New page pods.  "
943 	    "ps %p, ddp_pgsz %d, ppod 0x%x, npages %d, nppods %d",
944 	    ps, td->ddp_pgsz[idx], ppod, ps->npages, ps->nppods);
945 
946 	return (1);
947 }
948 
949 #define NUM_ULP_TX_SC_IMM_PPODS (256 / PPOD_SIZE)
950 
951 static int
952 write_page_pods(struct adapter *sc, struct toepcb *toep, struct pageset *ps)
953 {
954 	struct wrqe *wr;
955 	struct ulp_mem_io *ulpmc;
956 	struct ulptx_idata *ulpsc;
957 	struct pagepod *ppod;
958 	struct tom_data *td = sc->tom_softc;
959 	int i, j, k, n, chunk, len, ddp_pgsz, idx;
960 	u_int ppod_addr;
961 	uint32_t cmd;
962 
963 	KASSERT(!(ps->flags & PS_PPODS_WRITTEN),
964 	    ("%s: page pods already written", __func__));
965 
966 	cmd = htobe32(V_ULPTX_CMD(ULP_TX_MEM_WRITE));
967 	if (is_t4(sc))
968 		cmd |= htobe32(F_ULP_MEMIO_ORDER);
969 	else
970 		cmd |= htobe32(F_T5_ULP_MEMIO_IMM);
971 	ddp_pgsz = td->ddp_pgsz[G_PPOD_PGSZ(ps->tag)];
972 	ppod_addr = ps->ppod_addr;
973 	for (i = 0; i < ps->nppods; ppod_addr += chunk) {
974 
975 		/* How many page pods are we writing in this cycle */
976 		n = min(ps->nppods - i, NUM_ULP_TX_SC_IMM_PPODS);
977 		chunk = PPOD_SZ(n);
978 		len = roundup2(sizeof(*ulpmc) + sizeof(*ulpsc) + chunk, 16);
979 
980 		wr = alloc_wrqe(len, toep->ctrlq);
981 		if (wr == NULL)
982 			return (ENOMEM);	/* ok to just bail out */
983 		ulpmc = wrtod(wr);
984 
985 		INIT_ULPTX_WR(ulpmc, len, 0, 0);
986 		ulpmc->cmd = cmd;
987 		ulpmc->dlen = htobe32(V_ULP_MEMIO_DATA_LEN(chunk / 32));
988 		ulpmc->len16 = htobe32(howmany(len - sizeof(ulpmc->wr), 16));
989 		ulpmc->lock_addr = htobe32(V_ULP_MEMIO_ADDR(ppod_addr >> 5));
990 
991 		ulpsc = (struct ulptx_idata *)(ulpmc + 1);
992 		ulpsc->cmd_more = htobe32(V_ULPTX_CMD(ULP_TX_SC_IMM));
993 		ulpsc->len = htobe32(chunk);
994 
995 		ppod = (struct pagepod *)(ulpsc + 1);
996 		for (j = 0; j < n; i++, j++, ppod++) {
997 			ppod->vld_tid_pgsz_tag_color = htobe64(F_PPOD_VALID |
998 			    V_PPOD_TID(toep->tid) | ps->tag);
999 			ppod->len_offset = htobe64(V_PPOD_LEN(ps->len) |
1000 			    V_PPOD_OFST(ps->offset));
1001 			ppod->rsvd = 0;
1002 			idx = i * PPOD_PAGES * (ddp_pgsz / PAGE_SIZE);
1003 			for (k = 0; k < nitems(ppod->addr); k++) {
1004 				if (idx < ps->npages) {
1005 					ppod->addr[k] =
1006 					    htobe64(ps->pages[idx]->phys_addr);
1007 					idx += ddp_pgsz / PAGE_SIZE;
1008 				} else
1009 					ppod->addr[k] = 0;
1010 #if 0
1011 				CTR5(KTR_CXGBE,
1012 				    "%s: tid %d ppod[%d]->addr[%d] = %p",
1013 				    __func__, toep->tid, i, k,
1014 				    htobe64(ppod->addr[k]));
1015 #endif
1016 			}
1017 
1018 		}
1019 
1020 		t4_wrq_tx(sc, wr);
1021 	}
1022 	ps->flags |= PS_PPODS_WRITTEN;
1023 
1024 	return (0);
1025 }
1026 
1027 static void
1028 wire_pageset(struct pageset *ps)
1029 {
1030 	vm_page_t p;
1031 	int i;
1032 
1033 	KASSERT(!(ps->flags & PS_WIRED), ("pageset already wired"));
1034 
1035 	for (i = 0; i < ps->npages; i++) {
1036 		p = ps->pages[i];
1037 		vm_page_lock(p);
1038 		vm_page_wire(p);
1039 		vm_page_unhold(p);
1040 		vm_page_unlock(p);
1041 	}
1042 	ps->flags |= PS_WIRED;
1043 }
1044 
1045 /*
1046  * Prepare a pageset for DDP.  This wires the pageset and sets up page
1047  * pods.
1048  */
1049 static int
1050 prep_pageset(struct adapter *sc, struct toepcb *toep, struct pageset *ps)
1051 {
1052 	struct tom_data *td = sc->tom_softc;
1053 
1054 	if (!(ps->flags & PS_WIRED))
1055 		wire_pageset(ps);
1056 	if (ps->nppods == 0 && !alloc_page_pods(td, ps)) {
1057 		return (0);
1058 	}
1059 	if (!(ps->flags & PS_PPODS_WRITTEN) &&
1060 	    write_page_pods(sc, toep, ps) != 0) {
1061 		return (0);
1062 	}
1063 
1064 	return (1);
1065 }
1066 
1067 void
1068 t4_init_ddp(struct adapter *sc, struct tom_data *td)
1069 {
1070 	int i;
1071 	uint32_t r;
1072 
1073 	r = t4_read_reg(sc, A_ULP_RX_TDDP_PSZ);
1074 	td->ddp_pgsz[0] = 4096 << G_HPZ0(r);
1075 	td->ddp_pgsz[1] = 4096 << G_HPZ1(r);
1076 	td->ddp_pgsz[2] = 4096 << G_HPZ2(r);
1077 	td->ddp_pgsz[3] = 4096 << G_HPZ3(r);
1078 
1079 	/*
1080 	 * The SGL -> page pod algorithm requires the sizes to be in increasing
1081 	 * order.
1082 	 */
1083 	for (i = 1; i < nitems(td->ddp_pgsz); i++) {
1084 		if (td->ddp_pgsz[i] <= td->ddp_pgsz[i - 1])
1085 			return;
1086 	}
1087 
1088 	td->ppod_start = sc->vres.ddp.start;
1089 	td->ppod_arena = vmem_create("DDP page pods", sc->vres.ddp.start,
1090 	    sc->vres.ddp.size, PPOD_SIZE, 512, M_FIRSTFIT | M_NOWAIT);
1091 }
1092 
1093 void
1094 t4_uninit_ddp(struct adapter *sc __unused, struct tom_data *td)
1095 {
1096 
1097 	if (td->ppod_arena != NULL) {
1098 		vmem_destroy(td->ppod_arena);
1099 		td->ppod_arena = NULL;
1100 	}
1101 }
1102 
1103 static int
1104 pscmp(struct pageset *ps, struct vmspace *vm, vm_offset_t start, int npages,
1105     int pgoff, int len)
1106 {
1107 
1108 	if (ps->npages != npages || ps->offset != pgoff || ps->len != len)
1109 		return (1);
1110 
1111 	return (ps->vm != vm || ps->vm_timestamp != vm->vm_map.timestamp);
1112 }
1113 
1114 static int
1115 hold_aio(struct toepcb *toep, struct kaiocb *job, struct pageset **pps)
1116 {
1117 	struct vmspace *vm;
1118 	vm_map_t map;
1119 	vm_offset_t start, end, pgoff;
1120 	struct pageset *ps;
1121 	int n;
1122 
1123 	DDP_ASSERT_LOCKED(toep);
1124 
1125 	/*
1126 	 * The AIO subsystem will cancel and drain all requests before
1127 	 * permitting a process to exit or exec, so p_vmspace should
1128 	 * be stable here.
1129 	 */
1130 	vm = job->userproc->p_vmspace;
1131 	map = &vm->vm_map;
1132 	start = (uintptr_t)job->uaiocb.aio_buf;
1133 	pgoff = start & PAGE_MASK;
1134 	end = round_page(start + job->uaiocb.aio_nbytes);
1135 	start = trunc_page(start);
1136 
1137 	if (end - start > MAX_DDP_BUFFER_SIZE) {
1138 		/*
1139 		 * Truncate the request to a short read.
1140 		 * Alternatively, we could DDP in chunks to the larger
1141 		 * buffer, but that would be quite a bit more work.
1142 		 *
1143 		 * When truncating, round the request down to avoid
1144 		 * crossing a cache line on the final transaction.
1145 		 */
1146 		end = rounddown2(start + MAX_DDP_BUFFER_SIZE, CACHE_LINE_SIZE);
1147 #ifdef VERBOSE_TRACES
1148 		CTR4(KTR_CXGBE, "%s: tid %d, truncating size from %lu to %lu",
1149 		    __func__, toep->tid, (unsigned long)job->uaiocb.aio_nbytes,
1150 		    (unsigned long)(end - (start + pgoff)));
1151 		job->uaiocb.aio_nbytes = end - (start + pgoff);
1152 #endif
1153 		end = round_page(end);
1154 	}
1155 
1156 	n = atop(end - start);
1157 
1158 	/*
1159 	 * Try to reuse a cached pageset.
1160 	 */
1161 	TAILQ_FOREACH(ps, &toep->ddp_cached_pagesets, link) {
1162 		if (pscmp(ps, vm, start, n, pgoff,
1163 		    job->uaiocb.aio_nbytes) == 0) {
1164 			TAILQ_REMOVE(&toep->ddp_cached_pagesets, ps, link);
1165 			toep->ddp_cached_count--;
1166 			*pps = ps;
1167 			return (0);
1168 		}
1169 	}
1170 
1171 	/*
1172 	 * If there are too many cached pagesets to create a new one,
1173 	 * free a pageset before creating a new one.
1174 	 */
1175 	KASSERT(toep->ddp_active_count + toep->ddp_cached_count <=
1176 	    nitems(toep->db), ("%s: too many wired pagesets", __func__));
1177 	if (toep->ddp_active_count + toep->ddp_cached_count ==
1178 	    nitems(toep->db)) {
1179 		KASSERT(toep->ddp_cached_count > 0,
1180 		    ("no cached pageset to free"));
1181 		ps = TAILQ_LAST(&toep->ddp_cached_pagesets, pagesetq);
1182 		TAILQ_REMOVE(&toep->ddp_cached_pagesets, ps, link);
1183 		toep->ddp_cached_count--;
1184 		free_pageset(toep->td, ps);
1185 	}
1186 	DDP_UNLOCK(toep);
1187 
1188 	/* Create a new pageset. */
1189 	ps = malloc(sizeof(*ps) + n * sizeof(vm_page_t), M_CXGBE, M_WAITOK |
1190 	    M_ZERO);
1191 	ps->pages = (vm_page_t *)(ps + 1);
1192 	ps->vm_timestamp = map->timestamp;
1193 	ps->npages = vm_fault_quick_hold_pages(map, start, end - start,
1194 	    VM_PROT_WRITE, ps->pages, n);
1195 
1196 	DDP_LOCK(toep);
1197 	if (ps->npages < 0) {
1198 		free(ps, M_CXGBE);
1199 		return (EFAULT);
1200 	}
1201 
1202 	KASSERT(ps->npages == n, ("hold_aio: page count mismatch: %d vs %d",
1203 	    ps->npages, n));
1204 
1205 	ps->offset = pgoff;
1206 	ps->len = job->uaiocb.aio_nbytes;
1207 	atomic_add_int(&vm->vm_refcnt, 1);
1208 	ps->vm = vm;
1209 
1210 	CTR5(KTR_CXGBE, "%s: tid %d, new pageset %p for job %p, npages %d",
1211 	    __func__, toep->tid, ps, job, ps->npages);
1212 	*pps = ps;
1213 	return (0);
1214 }
1215 
1216 static void
1217 ddp_complete_all(struct toepcb *toep, int error)
1218 {
1219 	struct kaiocb *job;
1220 
1221 	DDP_ASSERT_LOCKED(toep);
1222 	while (!TAILQ_EMPTY(&toep->ddp_aiojobq)) {
1223 		job = TAILQ_FIRST(&toep->ddp_aiojobq);
1224 		TAILQ_REMOVE(&toep->ddp_aiojobq, job, list);
1225 		toep->ddp_waiting_count--;
1226 		if (aio_clear_cancel_function(job))
1227 			ddp_complete_one(job, error);
1228 	}
1229 }
1230 
1231 static void
1232 aio_ddp_cancel_one(struct kaiocb *job)
1233 {
1234 	long copied;
1235 
1236 	/*
1237 	 * If this job had copied data out of the socket buffer before
1238 	 * it was cancelled, report it as a short read rather than an
1239 	 * error.
1240 	 */
1241 	copied = job->aio_received;
1242 	if (copied != 0)
1243 		aio_complete(job, copied, 0);
1244 	else
1245 		aio_cancel(job);
1246 }
1247 
1248 /*
1249  * Called when the main loop wants to requeue a job to retry it later.
1250  * Deals with the race of the job being cancelled while it was being
1251  * examined.
1252  */
1253 static void
1254 aio_ddp_requeue_one(struct toepcb *toep, struct kaiocb *job)
1255 {
1256 
1257 	DDP_ASSERT_LOCKED(toep);
1258 	if (!(toep->ddp_flags & DDP_DEAD) &&
1259 	    aio_set_cancel_function(job, t4_aio_cancel_queued)) {
1260 		TAILQ_INSERT_HEAD(&toep->ddp_aiojobq, job, list);
1261 		toep->ddp_waiting_count++;
1262 	} else
1263 		aio_ddp_cancel_one(job);
1264 }
1265 
1266 static void
1267 aio_ddp_requeue(struct toepcb *toep)
1268 {
1269 	struct adapter *sc = td_adapter(toep->td);
1270 	struct socket *so;
1271 	struct sockbuf *sb;
1272 	struct inpcb *inp;
1273 	struct kaiocb *job;
1274 	struct ddp_buffer *db;
1275 	size_t copied, offset, resid;
1276 	struct pageset *ps;
1277 	struct mbuf *m;
1278 	uint64_t ddp_flags, ddp_flags_mask;
1279 	struct wrqe *wr;
1280 	int buf_flag, db_idx, error;
1281 
1282 	DDP_ASSERT_LOCKED(toep);
1283 
1284 restart:
1285 	if (toep->ddp_flags & DDP_DEAD) {
1286 		MPASS(toep->ddp_waiting_count == 0);
1287 		MPASS(toep->ddp_active_count == 0);
1288 		return;
1289 	}
1290 
1291 	if (toep->ddp_waiting_count == 0 ||
1292 	    toep->ddp_active_count == nitems(toep->db)) {
1293 		return;
1294 	}
1295 
1296 	job = TAILQ_FIRST(&toep->ddp_aiojobq);
1297 	so = job->fd_file->f_data;
1298 	sb = &so->so_rcv;
1299 	SOCKBUF_LOCK(sb);
1300 
1301 	/* We will never get anything unless we are or were connected. */
1302 	if (!(so->so_state & (SS_ISCONNECTED|SS_ISDISCONNECTED))) {
1303 		SOCKBUF_UNLOCK(sb);
1304 		ddp_complete_all(toep, ENOTCONN);
1305 		return;
1306 	}
1307 
1308 	KASSERT(toep->ddp_active_count == 0 || sbavail(sb) == 0,
1309 	    ("%s: pending sockbuf data and DDP is active", __func__));
1310 
1311 	/* Abort if socket has reported problems. */
1312 	/* XXX: Wait for any queued DDP's to finish and/or flush them? */
1313 	if (so->so_error && sbavail(sb) == 0) {
1314 		toep->ddp_waiting_count--;
1315 		TAILQ_REMOVE(&toep->ddp_aiojobq, job, list);
1316 		if (!aio_clear_cancel_function(job)) {
1317 			SOCKBUF_UNLOCK(sb);
1318 			goto restart;
1319 		}
1320 
1321 		/*
1322 		 * If this job has previously copied some data, report
1323 		 * a short read and leave the error to be reported by
1324 		 * a future request.
1325 		 */
1326 		copied = job->aio_received;
1327 		if (copied != 0) {
1328 			SOCKBUF_UNLOCK(sb);
1329 			aio_complete(job, copied, 0);
1330 			goto restart;
1331 		}
1332 		error = so->so_error;
1333 		so->so_error = 0;
1334 		SOCKBUF_UNLOCK(sb);
1335 		aio_complete(job, -1, error);
1336 		goto restart;
1337 	}
1338 
1339 	/*
1340 	 * Door is closed.  If there is pending data in the socket buffer,
1341 	 * deliver it.  If there are pending DDP requests, wait for those
1342 	 * to complete.  Once they have completed, return EOF reads.
1343 	 */
1344 	if (sb->sb_state & SBS_CANTRCVMORE && sbavail(sb) == 0) {
1345 		SOCKBUF_UNLOCK(sb);
1346 		if (toep->ddp_active_count != 0)
1347 			return;
1348 		ddp_complete_all(toep, 0);
1349 		return;
1350 	}
1351 
1352 	/*
1353 	 * If DDP is not enabled and there is no pending socket buffer
1354 	 * data, try to enable DDP.
1355 	 */
1356 	if (sbavail(sb) == 0 && (toep->ddp_flags & DDP_ON) == 0) {
1357 		SOCKBUF_UNLOCK(sb);
1358 
1359 		/*
1360 		 * Wait for the card to ACK that DDP is enabled before
1361 		 * queueing any buffers.  Currently this waits for an
1362 		 * indicate to arrive.  This could use a TCB_SET_FIELD_RPL
1363 		 * message to know that DDP was enabled instead of waiting
1364 		 * for the indicate which would avoid copying the indicate
1365 		 * if no data is pending.
1366 		 *
1367 		 * XXX: Might want to limit the indicate size to the size
1368 		 * of the first queued request.
1369 		 */
1370 		if ((toep->ddp_flags & DDP_SC_REQ) == 0)
1371 			enable_ddp(sc, toep);
1372 		return;
1373 	}
1374 	SOCKBUF_UNLOCK(sb);
1375 
1376 	/*
1377 	 * If another thread is queueing a buffer for DDP, let it
1378 	 * drain any work and return.
1379 	 */
1380 	if (toep->ddp_queueing != NULL)
1381 		return;
1382 
1383 	/* Take the next job to prep it for DDP. */
1384 	toep->ddp_waiting_count--;
1385 	TAILQ_REMOVE(&toep->ddp_aiojobq, job, list);
1386 	if (!aio_clear_cancel_function(job))
1387 		goto restart;
1388 	toep->ddp_queueing = job;
1389 
1390 	/* NB: This drops DDP_LOCK while it holds the backing VM pages. */
1391 	error = hold_aio(toep, job, &ps);
1392 	if (error != 0) {
1393 		ddp_complete_one(job, error);
1394 		toep->ddp_queueing = NULL;
1395 		goto restart;
1396 	}
1397 
1398 	SOCKBUF_LOCK(sb);
1399 	if (so->so_error && sbavail(sb) == 0) {
1400 		copied = job->aio_received;
1401 		if (copied != 0) {
1402 			SOCKBUF_UNLOCK(sb);
1403 			recycle_pageset(toep, ps);
1404 			aio_complete(job, copied, 0);
1405 			toep->ddp_queueing = NULL;
1406 			goto restart;
1407 		}
1408 
1409 		error = so->so_error;
1410 		so->so_error = 0;
1411 		SOCKBUF_UNLOCK(sb);
1412 		recycle_pageset(toep, ps);
1413 		aio_complete(job, -1, error);
1414 		toep->ddp_queueing = NULL;
1415 		goto restart;
1416 	}
1417 
1418 	if (sb->sb_state & SBS_CANTRCVMORE && sbavail(sb) == 0) {
1419 		SOCKBUF_UNLOCK(sb);
1420 		recycle_pageset(toep, ps);
1421 		if (toep->ddp_active_count != 0) {
1422 			/*
1423 			 * The door is closed, but there are still pending
1424 			 * DDP buffers.  Requeue.  These jobs will all be
1425 			 * completed once those buffers drain.
1426 			 */
1427 			aio_ddp_requeue_one(toep, job);
1428 			toep->ddp_queueing = NULL;
1429 			return;
1430 		}
1431 		ddp_complete_one(job, 0);
1432 		ddp_complete_all(toep, 0);
1433 		toep->ddp_queueing = NULL;
1434 		return;
1435 	}
1436 
1437 sbcopy:
1438 	/*
1439 	 * If the toep is dead, there shouldn't be any data in the socket
1440 	 * buffer, so the above case should have handled this.
1441 	 */
1442 	MPASS(!(toep->ddp_flags & DDP_DEAD));
1443 
1444 	/*
1445 	 * If there is pending data in the socket buffer (either
1446 	 * from before the requests were queued or a DDP indicate),
1447 	 * copy those mbufs out directly.
1448 	 */
1449 	copied = 0;
1450 	offset = ps->offset + job->aio_received;
1451 	MPASS(job->aio_received <= job->uaiocb.aio_nbytes);
1452 	resid = job->uaiocb.aio_nbytes - job->aio_received;
1453 	m = sb->sb_mb;
1454 	KASSERT(m == NULL || toep->ddp_active_count == 0,
1455 	    ("%s: sockbuf data with active DDP", __func__));
1456 	while (m != NULL && resid > 0) {
1457 		struct iovec iov[1];
1458 		struct uio uio;
1459 		int error;
1460 
1461 		iov[0].iov_base = mtod(m, void *);
1462 		iov[0].iov_len = m->m_len;
1463 		if (iov[0].iov_len > resid)
1464 			iov[0].iov_len = resid;
1465 		uio.uio_iov = iov;
1466 		uio.uio_iovcnt = 1;
1467 		uio.uio_offset = 0;
1468 		uio.uio_resid = iov[0].iov_len;
1469 		uio.uio_segflg = UIO_SYSSPACE;
1470 		uio.uio_rw = UIO_WRITE;
1471 		error = uiomove_fromphys(ps->pages, offset + copied,
1472 		    uio.uio_resid, &uio);
1473 		MPASS(error == 0 && uio.uio_resid == 0);
1474 		copied += uio.uio_offset;
1475 		resid -= uio.uio_offset;
1476 		m = m->m_next;
1477 	}
1478 	if (copied != 0) {
1479 		sbdrop_locked(sb, copied);
1480 		job->aio_received += copied;
1481 		job->msgrcv = 1;
1482 		copied = job->aio_received;
1483 		inp = sotoinpcb(so);
1484 		if (!INP_TRY_WLOCK(inp)) {
1485 			/*
1486 			 * The reference on the socket file descriptor in
1487 			 * the AIO job should keep 'sb' and 'inp' stable.
1488 			 * Our caller has a reference on the 'toep' that
1489 			 * keeps it stable.
1490 			 */
1491 			SOCKBUF_UNLOCK(sb);
1492 			DDP_UNLOCK(toep);
1493 			INP_WLOCK(inp);
1494 			DDP_LOCK(toep);
1495 			SOCKBUF_LOCK(sb);
1496 
1497 			/*
1498 			 * If the socket has been closed, we should detect
1499 			 * that and complete this request if needed on
1500 			 * the next trip around the loop.
1501 			 */
1502 		}
1503 		t4_rcvd_locked(&toep->td->tod, intotcpcb(inp));
1504 		INP_WUNLOCK(inp);
1505 		if (resid == 0 || toep->ddp_flags & DDP_DEAD) {
1506 			/*
1507 			 * We filled the entire buffer with socket
1508 			 * data, DDP is not being used, or the socket
1509 			 * is being shut down, so complete the
1510 			 * request.
1511 			 */
1512 			SOCKBUF_UNLOCK(sb);
1513 			recycle_pageset(toep, ps);
1514 			aio_complete(job, copied, 0);
1515 			toep->ddp_queueing = NULL;
1516 			goto restart;
1517 		}
1518 
1519 		/*
1520 		 * If DDP is not enabled, requeue this request and restart.
1521 		 * This will either enable DDP or wait for more data to
1522 		 * arrive on the socket buffer.
1523 		 */
1524 		if ((toep->ddp_flags & (DDP_ON | DDP_SC_REQ)) != DDP_ON) {
1525 			SOCKBUF_UNLOCK(sb);
1526 			recycle_pageset(toep, ps);
1527 			aio_ddp_requeue_one(toep, job);
1528 			toep->ddp_queueing = NULL;
1529 			goto restart;
1530 		}
1531 
1532 		/*
1533 		 * An indicate might have arrived and been added to
1534 		 * the socket buffer while it was unlocked after the
1535 		 * copy to lock the INP.  If so, restart the copy.
1536 		 */
1537 		if (sbavail(sb) != 0)
1538 			goto sbcopy;
1539 	}
1540 	SOCKBUF_UNLOCK(sb);
1541 
1542 	if (prep_pageset(sc, toep, ps) == 0) {
1543 		recycle_pageset(toep, ps);
1544 		aio_ddp_requeue_one(toep, job);
1545 		toep->ddp_queueing = NULL;
1546 
1547 		/*
1548 		 * XXX: Need to retry this later.  Mostly need a trigger
1549 		 * when page pods are freed up.
1550 		 */
1551 		printf("%s: prep_pageset failed\n", __func__);
1552 		return;
1553 	}
1554 
1555 	/* Determine which DDP buffer to use. */
1556 	if (toep->db[0].job == NULL) {
1557 		db_idx = 0;
1558 	} else {
1559 		MPASS(toep->db[1].job == NULL);
1560 		db_idx = 1;
1561 	}
1562 
1563 	ddp_flags = 0;
1564 	ddp_flags_mask = 0;
1565 	if (db_idx == 0) {
1566 		ddp_flags |= V_TF_DDP_BUF0_VALID(1);
1567 		if (so->so_state & SS_NBIO)
1568 			ddp_flags |= V_TF_DDP_BUF0_FLUSH(1);
1569 		ddp_flags_mask |= V_TF_DDP_PSH_NO_INVALIDATE0(1) |
1570 		    V_TF_DDP_PUSH_DISABLE_0(1) | V_TF_DDP_PSHF_ENABLE_0(1) |
1571 		    V_TF_DDP_BUF0_FLUSH(1) | V_TF_DDP_BUF0_VALID(1);
1572 		buf_flag = DDP_BUF0_ACTIVE;
1573 	} else {
1574 		ddp_flags |= V_TF_DDP_BUF1_VALID(1);
1575 		if (so->so_state & SS_NBIO)
1576 			ddp_flags |= V_TF_DDP_BUF1_FLUSH(1);
1577 		ddp_flags_mask |= V_TF_DDP_PSH_NO_INVALIDATE1(1) |
1578 		    V_TF_DDP_PUSH_DISABLE_1(1) | V_TF_DDP_PSHF_ENABLE_1(1) |
1579 		    V_TF_DDP_BUF1_FLUSH(1) | V_TF_DDP_BUF1_VALID(1);
1580 		buf_flag = DDP_BUF1_ACTIVE;
1581 	}
1582 	MPASS((toep->ddp_flags & buf_flag) == 0);
1583 	if ((toep->ddp_flags & (DDP_BUF0_ACTIVE | DDP_BUF1_ACTIVE)) == 0) {
1584 		MPASS(db_idx == 0);
1585 		MPASS(toep->ddp_active_id == -1);
1586 		MPASS(toep->ddp_active_count == 0);
1587 		ddp_flags_mask |= V_TF_DDP_ACTIVE_BUF(1);
1588 	}
1589 
1590 	/*
1591 	 * The TID for this connection should still be valid.  If DDP_DEAD
1592 	 * is set, SBS_CANTRCVMORE should be set, so we shouldn't be
1593 	 * this far anyway.  Even if the socket is closing on the other
1594 	 * end, the AIO job holds a reference on this end of the socket
1595 	 * which will keep it open and keep the TCP PCB attached until
1596 	 * after the job is completed.
1597 	 */
1598 	wr = mk_update_tcb_for_ddp(sc, toep, db_idx, ps, job->aio_received,
1599 	    ddp_flags, ddp_flags_mask);
1600 	if (wr == NULL) {
1601 		recycle_pageset(toep, ps);
1602 		aio_ddp_requeue_one(toep, job);
1603 		toep->ddp_queueing = NULL;
1604 
1605 		/*
1606 		 * XXX: Need a way to kick a retry here.
1607 		 *
1608 		 * XXX: We know the fixed size needed and could
1609 		 * preallocate this using a blocking request at the
1610 		 * start of the task to avoid having to handle this
1611 		 * edge case.
1612 		 */
1613 		printf("%s: mk_update_tcb_for_ddp failed\n", __func__);
1614 		return;
1615 	}
1616 
1617 	if (!aio_set_cancel_function(job, t4_aio_cancel_active)) {
1618 		free_wrqe(wr);
1619 		recycle_pageset(toep, ps);
1620 		aio_ddp_cancel_one(job);
1621 		toep->ddp_queueing = NULL;
1622 		goto restart;
1623 	}
1624 
1625 #ifdef VERBOSE_TRACES
1626 	CTR5(KTR_CXGBE, "%s: scheduling %p for DDP[%d] (flags %#lx/%#lx)",
1627 	    __func__, job, db_idx, ddp_flags, ddp_flags_mask);
1628 #endif
1629 	/* Give the chip the go-ahead. */
1630 	t4_wrq_tx(sc, wr);
1631 	db = &toep->db[db_idx];
1632 	db->cancel_pending = 0;
1633 	db->job = job;
1634 	db->ps = ps;
1635 	toep->ddp_queueing = NULL;
1636 	toep->ddp_flags |= buf_flag;
1637 	toep->ddp_active_count++;
1638 	if (toep->ddp_active_count == 1) {
1639 		MPASS(toep->ddp_active_id == -1);
1640 		toep->ddp_active_id = db_idx;
1641 		CTR2(KTR_CXGBE, "%s: ddp_active_id = %d", __func__,
1642 		    toep->ddp_active_id);
1643 	}
1644 	goto restart;
1645 }
1646 
1647 void
1648 ddp_queue_toep(struct toepcb *toep)
1649 {
1650 
1651 	DDP_ASSERT_LOCKED(toep);
1652 	if (toep->ddp_flags & DDP_TASK_ACTIVE)
1653 		return;
1654 	toep->ddp_flags |= DDP_TASK_ACTIVE;
1655 	hold_toepcb(toep);
1656 	soaio_enqueue(&toep->ddp_requeue_task);
1657 }
1658 
1659 static void
1660 aio_ddp_requeue_task(void *context, int pending)
1661 {
1662 	struct toepcb *toep = context;
1663 
1664 	DDP_LOCK(toep);
1665 	aio_ddp_requeue(toep);
1666 	toep->ddp_flags &= ~DDP_TASK_ACTIVE;
1667 	DDP_UNLOCK(toep);
1668 
1669 	free_toepcb(toep);
1670 }
1671 
1672 static void
1673 t4_aio_cancel_active(struct kaiocb *job)
1674 {
1675 	struct socket *so = job->fd_file->f_data;
1676 	struct tcpcb *tp = so_sototcpcb(so);
1677 	struct toepcb *toep = tp->t_toe;
1678 	struct adapter *sc = td_adapter(toep->td);
1679 	uint64_t valid_flag;
1680 	int i;
1681 
1682 	DDP_LOCK(toep);
1683 	if (aio_cancel_cleared(job)) {
1684 		DDP_UNLOCK(toep);
1685 		aio_ddp_cancel_one(job);
1686 		return;
1687 	}
1688 
1689 	for (i = 0; i < nitems(toep->db); i++) {
1690 		if (toep->db[i].job == job) {
1691 			/* Should only ever get one cancel request for a job. */
1692 			MPASS(toep->db[i].cancel_pending == 0);
1693 
1694 			/*
1695 			 * Invalidate this buffer.  It will be
1696 			 * cancelled or partially completed once the
1697 			 * card ACKs the invalidate.
1698 			 */
1699 			valid_flag = i == 0 ? V_TF_DDP_BUF0_VALID(1) :
1700 			    V_TF_DDP_BUF1_VALID(1);
1701 			t4_set_tcb_field(sc, toep->ctrlq, toep->tid,
1702 			    W_TCB_RX_DDP_FLAGS, valid_flag, 0, 1,
1703 			    i + DDP_BUF0_INVALIDATED,
1704 			    toep->ofld_rxq->iq.abs_id);
1705 			toep->db[i].cancel_pending = 1;
1706 			CTR2(KTR_CXGBE, "%s: request %p marked pending",
1707 			    __func__, job);
1708 			break;
1709 		}
1710 	}
1711 	DDP_UNLOCK(toep);
1712 }
1713 
1714 static void
1715 t4_aio_cancel_queued(struct kaiocb *job)
1716 {
1717 	struct socket *so = job->fd_file->f_data;
1718 	struct tcpcb *tp = so_sototcpcb(so);
1719 	struct toepcb *toep = tp->t_toe;
1720 
1721 	DDP_LOCK(toep);
1722 	if (!aio_cancel_cleared(job)) {
1723 		TAILQ_REMOVE(&toep->ddp_aiojobq, job, list);
1724 		toep->ddp_waiting_count--;
1725 		if (toep->ddp_waiting_count == 0)
1726 			ddp_queue_toep(toep);
1727 	}
1728 	CTR2(KTR_CXGBE, "%s: request %p cancelled", __func__, job);
1729 	DDP_UNLOCK(toep);
1730 
1731 	aio_ddp_cancel_one(job);
1732 }
1733 
1734 int
1735 t4_aio_queue_ddp(struct socket *so, struct kaiocb *job)
1736 {
1737 	struct tcpcb *tp = so_sototcpcb(so);
1738 	struct toepcb *toep = tp->t_toe;
1739 
1740 
1741 	/* Ignore writes. */
1742 	if (job->uaiocb.aio_lio_opcode != LIO_READ)
1743 		return (EOPNOTSUPP);
1744 
1745 	DDP_LOCK(toep);
1746 
1747 	/*
1748 	 * XXX: Think about possibly returning errors for ENOTCONN,
1749 	 * etc.  Perhaps the caller would only queue the request
1750 	 * if it failed with EOPNOTSUPP?
1751 	 */
1752 
1753 #ifdef VERBOSE_TRACES
1754 	CTR2(KTR_CXGBE, "%s: queueing %p", __func__, job);
1755 #endif
1756 	if (!aio_set_cancel_function(job, t4_aio_cancel_queued))
1757 		panic("new job was cancelled");
1758 	TAILQ_INSERT_TAIL(&toep->ddp_aiojobq, job, list);
1759 	toep->ddp_waiting_count++;
1760 	toep->ddp_flags |= DDP_OK;
1761 
1762 	/*
1763 	 * Try to handle this request synchronously.  If this has
1764 	 * to block because the task is running, it will just bail
1765 	 * and let the task handle it instead.
1766 	 */
1767 	aio_ddp_requeue(toep);
1768 	DDP_UNLOCK(toep);
1769 	return (0);
1770 }
1771 
1772 int
1773 t4_ddp_mod_load(void)
1774 {
1775 
1776 	t4_register_cpl_handler(CPL_RX_DATA_DDP, do_rx_data_ddp);
1777 	t4_register_cpl_handler(CPL_RX_DDP_COMPLETE, do_rx_ddp_complete);
1778 	TAILQ_INIT(&ddp_orphan_pagesets);
1779 	mtx_init(&ddp_orphan_pagesets_lock, "ddp orphans", NULL, MTX_DEF);
1780 	TASK_INIT(&ddp_orphan_task, 0, ddp_free_orphan_pagesets, NULL);
1781 	return (0);
1782 }
1783 
1784 void
1785 t4_ddp_mod_unload(void)
1786 {
1787 
1788 	taskqueue_drain(taskqueue_thread, &ddp_orphan_task);
1789 	MPASS(TAILQ_EMPTY(&ddp_orphan_pagesets));
1790 	mtx_destroy(&ddp_orphan_pagesets_lock);
1791 	t4_register_cpl_handler(CPL_RX_DATA_DDP, NULL);
1792 	t4_register_cpl_handler(CPL_RX_DDP_COMPLETE, NULL);
1793 }
1794 #endif
1795