xref: /titanic_41/usr/src/uts/common/rpc/xdr_rdma.c (revision d24234c24aeaca4ca56ee3ac2794507968f274c4)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * Copyright (c) 2007, The Ohio State University. All rights reserved.
28  *
29  * Portions of this source code is developed by the team members of
30  * The Ohio State University's Network-Based Computing Laboratory (NBCL),
31  * headed by Professor Dhabaleswar K. (DK) Panda.
32  *
33  * Acknowledgements to contributions from developors:
34  *   Ranjit Noronha: noronha@cse.ohio-state.edu
35  *   Lei Chai      : chail@cse.ohio-state.edu
36  *   Weikuan Yu    : yuw@cse.ohio-state.edu
37  *
38  */
39 
40 /*
41  * xdr_rdma.c, XDR implementation using RDMA to move large chunks
42  */
43 
44 #include <sys/param.h>
45 #include <sys/types.h>
46 #include <sys/systm.h>
47 #include <sys/kmem.h>
48 #include <sys/sdt.h>
49 #include <sys/debug.h>
50 
51 #include <rpc/types.h>
52 #include <rpc/xdr.h>
53 #include <sys/cmn_err.h>
54 #include <rpc/rpc_sztypes.h>
55 #include <rpc/rpc_rdma.h>
56 #include <sys/sysmacros.h>
57 
58 static bool_t   xdrrdma_getint32(XDR *, int32_t *);
59 static bool_t   xdrrdma_putint32(XDR *, int32_t *);
60 static bool_t   xdrrdma_getbytes(XDR *, caddr_t, int);
61 static bool_t   xdrrdma_putbytes(XDR *, caddr_t, int);
62 uint_t		xdrrdma_getpos(XDR *);
63 bool_t		xdrrdma_setpos(XDR *, uint_t);
64 static rpc_inline_t *xdrrdma_inline(XDR *, int);
65 void		xdrrdma_destroy(XDR *);
66 static bool_t   xdrrdma_control(XDR *, int, void *);
67 static bool_t  xdrrdma_read_a_chunk(XDR *, CONN **);
68 static void xdrrdma_free_xdr_chunks(CONN *, struct clist *);
69 
70 struct xdr_ops  xdrrdmablk_ops = {
71 	xdrrdma_getbytes,
72 	xdrrdma_putbytes,
73 	xdrrdma_getpos,
74 	xdrrdma_setpos,
75 	xdrrdma_inline,
76 	xdrrdma_destroy,
77 	xdrrdma_control,
78 	xdrrdma_getint32,
79 	xdrrdma_putint32
80 };
81 
82 struct xdr_ops  xdrrdma_ops = {
83 	xdrrdma_getbytes,
84 	xdrrdma_putbytes,
85 	xdrrdma_getpos,
86 	xdrrdma_setpos,
87 	xdrrdma_inline,
88 	xdrrdma_destroy,
89 	xdrrdma_control,
90 	xdrrdma_getint32,
91 	xdrrdma_putint32
92 };
93 
94 /*
95  * A chunk list entry identifies a chunk of opaque data to be moved
96  * separately from the rest of the RPC message. xp_min_chunk = 0, is a
97  * special case for ENCODING, which means do not chunk the incoming stream of
98  * data.
99  *
100  * A read chunk can contain part of the RPC message in addition to the
101  * inline message. In such a case, (xp_offp - x_base) will not provide
102  * the correct xdr offset of the entire message. xp_off is used in such
103  * a case to denote the offset or current position in the overall message
104  * covering both the inline and the chunk. This is used only in the case
105  * of decoding and useful to compare read chunk 'c_xdroff' offsets.
106  *
107  * An example for a read chunk containing an XDR message:
108  * An NFSv4 compound as following:
109  *
110  * PUTFH
111  * WRITE [4109 bytes]
112  * GETATTR
113  *
114  * Solaris Encoding is:
115  * -------------------
116  *
117  * <Inline message>: [PUTFH WRITE4args GETATTR]
118  *                                   |
119  *                                   v
120  * [RDMA_READ chunks]:               [write data]
121  *
122  *
123  * Linux encoding is:
124  * -----------------
125  *
126  * <Inline message>: [PUTFH WRITE4args]
127  *                                    |
128  *                                    v
129  * [RDMA_READ chunks]:                [Write data] [Write data2] [Getattr chunk]
130  *                                     chunk1       chunk2         chunk3
131  *
132  * where the READ chunks are as:
133  *
134  *             - chunk1 - 4k
135  * write data |
136  *             - chunk2 - 13 bytes(4109 - 4k)
137  * getattr op  - chunk3 - 19 bytes
138  * (getattr op starts at byte 4 after 3 bytes of roundup)
139  *
140  */
141 
142 typedef struct {
143 	caddr_t		xp_offp;
144 	int		xp_min_chunk;
145 	uint_t		xp_flags;	/* Controls setting for rdma xdr */
146 	int		xp_buf_size;	/* size of xdr buffer */
147 	int		xp_off;		/* overall offset */
148 	struct clist	*xp_rcl;	/* head of chunk list */
149 	struct clist	**xp_rcl_next;	/* location to place/find next chunk */
150 	struct clist	*xp_rcl_xdr;	/* copy of rcl containing RPC message */
151 	struct clist	*xp_wcl;	/* head of write chunk list */
152 	CONN		*xp_conn;	/* connection for chunk data xfer */
153 	uint_t		xp_reply_chunk_len;
154 	/* used to track length for security modes: integrity/privacy */
155 	uint_t		xp_reply_chunk_len_alt;
156 } xrdma_private_t;
157 
158 extern kmem_cache_t *clist_cache;
159 
160 bool_t
161 xdrrdma_getrdmablk(XDR *xdrs, struct clist **rlist, uint_t *sizep,
162     CONN **conn, const uint_t maxsize)
163 {
164 	xrdma_private_t	*xdrp = (xrdma_private_t *)(xdrs->x_private);
165 	struct clist	*cle = *(xdrp->xp_rcl_next);
166 	struct clist	*rdclist = NULL, *prev = NULL;
167 	bool_t		retval = TRUE;
168 	uint32_t	cur_offset = 0;
169 	uint32_t	total_segments = 0;
170 	uint32_t	actual_segments = 0;
171 	uint32_t	alen;
172 	uint_t		total_len;
173 
174 	ASSERT(xdrs->x_op != XDR_FREE);
175 
176 	/*
177 	 * first deal with the length since xdr bytes are counted
178 	 */
179 	if (!xdr_u_int(xdrs, sizep)) {
180 		DTRACE_PROBE(xdr__e__getrdmablk_sizep_fail);
181 		return (FALSE);
182 	}
183 	total_len = *sizep;
184 	if (total_len > maxsize) {
185 		DTRACE_PROBE2(xdr__e__getrdmablk_bad_size,
186 		    int, total_len, int, maxsize);
187 		return (FALSE);
188 	}
189 	(*conn) = xdrp->xp_conn;
190 
191 	/*
192 	 * if no data we are done
193 	 */
194 	if (total_len == 0)
195 		return (TRUE);
196 
197 	while (cle) {
198 		total_segments++;
199 		cle = cle->c_next;
200 	}
201 
202 	cle = *(xdrp->xp_rcl_next);
203 
204 	/*
205 	 * If there was a chunk at the current offset, then setup a read
206 	 * chunk list which records the destination address and length
207 	 * and will RDMA READ the data in later.
208 	 */
209 	if (cle == NULL)
210 		return (FALSE);
211 
212 	if (cle->c_xdroff != (xdrp->xp_offp - xdrs->x_base))
213 		return (FALSE);
214 
215 	/*
216 	 * Setup the chunk list with appropriate
217 	 * address (offset) and length
218 	 */
219 	for (actual_segments = 0;
220 	    actual_segments < total_segments; actual_segments++) {
221 
222 		DTRACE_PROBE3(krpc__i__xdrrdma_getrdmablk, uint32_t, cle->c_len,
223 		    uint32_t, total_len, uint32_t, cle->c_xdroff);
224 
225 		if (total_len <= 0)
226 			break;
227 
228 		/*
229 		 * not the first time in the loop
230 		 */
231 		if (actual_segments > 0)
232 			cle = cle->c_next;
233 
234 		cle->u.c_daddr = (uint64) cur_offset;
235 		alen = 0;
236 		if (cle->c_len > total_len) {
237 			alen = cle->c_len;
238 			cle->c_len = total_len;
239 		}
240 		if (!alen)
241 			xdrp->xp_rcl_next = &cle->c_next;
242 
243 		cur_offset += cle->c_len;
244 		total_len -= cle->c_len;
245 
246 		if ((total_segments - actual_segments - 1) == 0 &&
247 		    total_len > 0) {
248 			DTRACE_PROBE(krpc__e__xdrrdma_getblk_chunktooshort);
249 			retval = FALSE;
250 		}
251 
252 		if ((total_segments - actual_segments - 1) > 0 &&
253 		    total_len == 0) {
254 			DTRACE_PROBE2(krpc__e__xdrrdma_getblk_toobig,
255 			    int, total_segments, int, actual_segments);
256 		}
257 
258 		rdclist = clist_alloc();
259 		(*rdclist) = (*cle);
260 		if ((*rlist) == NULL)
261 			(*rlist) = rdclist;
262 		if (prev == NULL)
263 			prev = rdclist;
264 		else {
265 			prev->c_next = rdclist;
266 			prev = rdclist;
267 		}
268 
269 	}
270 
271 out:
272 	if (prev != NULL)
273 		prev->c_next = NULL;
274 
275 	/*
276 	 * Adjust the chunk length, if we read only a part of
277 	 * a chunk.
278 	 */
279 
280 	if (alen) {
281 		cle->w.c_saddr =
282 		    (uint64)(uintptr_t)cle->w.c_saddr + cle->c_len;
283 		cle->c_len = alen - cle->c_len;
284 	}
285 
286 	return (retval);
287 }
288 
289 /*
290  * The procedure xdrrdma_create initializes a stream descriptor for a memory
291  * buffer.
292  */
293 void
294 xdrrdma_create(XDR *xdrs, caddr_t addr, uint_t size,
295     int min_chunk, struct clist *cl, enum xdr_op op, CONN *conn)
296 {
297 	xrdma_private_t *xdrp;
298 	struct clist   *cle;
299 
300 	xdrs->x_op = op;
301 	xdrs->x_ops = &xdrrdma_ops;
302 	xdrs->x_base = addr;
303 	xdrs->x_handy = size;
304 	xdrs->x_public = NULL;
305 
306 	xdrp = (xrdma_private_t *)kmem_zalloc(sizeof (xrdma_private_t),
307 	    KM_SLEEP);
308 	xdrs->x_private = (caddr_t)xdrp;
309 	xdrp->xp_offp = addr;
310 	xdrp->xp_min_chunk = min_chunk;
311 	xdrp->xp_flags = 0;
312 	xdrp->xp_buf_size = size;
313 	xdrp->xp_rcl = cl;
314 	xdrp->xp_reply_chunk_len = 0;
315 	xdrp->xp_reply_chunk_len_alt = 0;
316 
317 	if (op == XDR_ENCODE && cl != NULL) {
318 		/* Find last element in chunk list and set xp_rcl_next */
319 		for (cle = cl; cle->c_next != NULL; cle = cle->c_next)
320 			continue;
321 
322 		xdrp->xp_rcl_next = &(cle->c_next);
323 	} else {
324 		xdrp->xp_rcl_next = &(xdrp->xp_rcl);
325 	}
326 
327 	xdrp->xp_wcl = NULL;
328 
329 	xdrp->xp_conn = conn;
330 	if (xdrp->xp_min_chunk != 0)
331 		xdrp->xp_flags |= XDR_RDMA_CHUNK;
332 }
333 
334 /* ARGSUSED */
335 void
336 xdrrdma_destroy(XDR * xdrs)
337 {
338 	xrdma_private_t	*xdrp = (xrdma_private_t *)(xdrs->x_private);
339 
340 	if (xdrp == NULL)
341 		return;
342 
343 	if (xdrp->xp_wcl) {
344 		if (xdrp->xp_flags & XDR_RDMA_WLIST_REG) {
345 			(void) clist_deregister(xdrp->xp_conn, xdrp->xp_wcl);
346 			rdma_buf_free(xdrp->xp_conn,
347 			    &xdrp->xp_wcl->rb_longbuf);
348 		}
349 		clist_free(xdrp->xp_wcl);
350 	}
351 
352 	if (xdrp->xp_rcl) {
353 		if (xdrp->xp_flags & XDR_RDMA_RLIST_REG) {
354 			(void) clist_deregister(xdrp->xp_conn, xdrp->xp_rcl);
355 			rdma_buf_free(xdrp->xp_conn,
356 			    &xdrp->xp_rcl->rb_longbuf);
357 		}
358 		clist_free(xdrp->xp_rcl);
359 	}
360 
361 	if (xdrp->xp_rcl_xdr)
362 		xdrrdma_free_xdr_chunks(xdrp->xp_conn, xdrp->xp_rcl_xdr);
363 
364 	(void) kmem_free(xdrs->x_private, sizeof (xrdma_private_t));
365 	xdrs->x_private = NULL;
366 }
367 
368 static	bool_t
369 xdrrdma_getint32(XDR *xdrs, int32_t *int32p)
370 {
371 	xrdma_private_t	*xdrp = (xrdma_private_t *)(xdrs->x_private);
372 	int chunked = 0;
373 
374 	if ((xdrs->x_handy -= (int)sizeof (int32_t)) < 0) {
375 		/*
376 		 * check if rest of the rpc message is in a chunk
377 		 */
378 		if (!xdrrdma_read_a_chunk(xdrs, &xdrp->xp_conn)) {
379 			return (FALSE);
380 		}
381 		chunked = 1;
382 	}
383 
384 	/* LINTED pointer alignment */
385 	*int32p = (int32_t)ntohl((uint32_t)(*((int32_t *)(xdrp->xp_offp))));
386 
387 	DTRACE_PROBE1(krpc__i__xdrrdma_getint32, int32_t, *int32p);
388 
389 	xdrp->xp_offp += sizeof (int32_t);
390 
391 	if (chunked)
392 		xdrs->x_handy -= (int)sizeof (int32_t);
393 
394 	if (xdrp->xp_off != 0) {
395 		xdrp->xp_off += sizeof (int32_t);
396 	}
397 
398 	return (TRUE);
399 }
400 
401 static	bool_t
402 xdrrdma_putint32(XDR *xdrs, int32_t *int32p)
403 {
404 	xrdma_private_t	*xdrp = (xrdma_private_t *)(xdrs->x_private);
405 
406 	if ((xdrs->x_handy -= (int)sizeof (int32_t)) < 0)
407 		return (FALSE);
408 
409 	/* LINTED pointer alignment */
410 	*(int32_t *)xdrp->xp_offp = (int32_t)htonl((uint32_t)(*int32p));
411 	xdrp->xp_offp += sizeof (int32_t);
412 
413 	return (TRUE);
414 }
415 
416 /*
417  * DECODE bytes from XDR stream for rdma.
418  * If the XDR stream contains a read chunk list,
419  * it will go through xdrrdma_getrdmablk instead.
420  */
421 static	bool_t
422 xdrrdma_getbytes(XDR *xdrs, caddr_t addr, int len)
423 {
424 	xrdma_private_t	*xdrp = (xrdma_private_t *)(xdrs->x_private);
425 	struct clist	*cle = *(xdrp->xp_rcl_next);
426 	struct clist	*cls = *(xdrp->xp_rcl_next);
427 	struct clist	cl;
428 	bool_t		retval = TRUE;
429 	uint32_t	total_len = len;
430 	uint32_t	cur_offset = 0;
431 	uint32_t	total_segments = 0;
432 	uint32_t	actual_segments = 0;
433 	uint32_t	status = RDMA_SUCCESS;
434 	uint32_t	alen = 0;
435 	uint32_t	xpoff;
436 
437 	while (cle) {
438 		total_segments++;
439 		cle = cle->c_next;
440 	}
441 
442 	cle = *(xdrp->xp_rcl_next);
443 
444 	if (xdrp->xp_off) {
445 		xpoff = xdrp->xp_off;
446 	} else {
447 		xpoff = (xdrp->xp_offp - xdrs->x_base);
448 	}
449 
450 	/*
451 	 * If there was a chunk at the current offset, then setup a read
452 	 * chunk list which records the destination address and length
453 	 * and will RDMA READ the data in later.
454 	 */
455 
456 	if (cle != NULL && cle->c_xdroff == xpoff) {
457 		for (actual_segments = 0;
458 		    actual_segments < total_segments; actual_segments++) {
459 
460 			if (total_len <= 0)
461 				break;
462 
463 			if (status != RDMA_SUCCESS)
464 				goto out;
465 
466 			cle->u.c_daddr = (uint64)(uintptr_t)addr + cur_offset;
467 			alen = 0;
468 			if (cle->c_len > total_len) {
469 				alen = cle->c_len;
470 				cle->c_len = total_len;
471 			}
472 			if (!alen)
473 				xdrp->xp_rcl_next = &cle->c_next;
474 
475 			cur_offset += cle->c_len;
476 			total_len -= cle->c_len;
477 
478 			if ((total_segments - actual_segments - 1) == 0 &&
479 			    total_len > 0) {
480 				DTRACE_PROBE(
481 				    krpc__e__xdrrdma_getbytes_chunktooshort);
482 				retval = FALSE;
483 			}
484 
485 			if ((total_segments - actual_segments - 1) > 0 &&
486 			    total_len == 0) {
487 				DTRACE_PROBE2(krpc__e__xdrrdma_getbytes_toobig,
488 				    int, total_segments, int, actual_segments);
489 			}
490 
491 			/*
492 			 * RDMA READ the chunk data from the remote end.
493 			 * First prep the destination buffer by registering
494 			 * it, then RDMA READ the chunk data. Since we are
495 			 * doing streaming memory, sync the destination
496 			 * buffer to CPU and deregister the buffer.
497 			 */
498 			if (xdrp->xp_conn == NULL) {
499 				return (FALSE);
500 			}
501 			cl = *cle;
502 			cl.c_next = NULL;
503 			status = clist_register(xdrp->xp_conn, &cl,
504 			    CLIST_REG_DST);
505 			if (status != RDMA_SUCCESS) {
506 				retval = FALSE;
507 				/*
508 				 * Deregister the previous chunks
509 				 * before return
510 				 */
511 				goto out;
512 			}
513 
514 			cle->c_dmemhandle = cl.c_dmemhandle;
515 			cle->c_dsynchandle = cl.c_dsynchandle;
516 
517 			/*
518 			 * Now read the chunk in
519 			 */
520 			if ((total_segments - actual_segments - 1) == 0 ||
521 			    total_len == 0) {
522 				status = RDMA_READ(xdrp->xp_conn, &cl, WAIT);
523 			} else {
524 				status = RDMA_READ(xdrp->xp_conn, &cl, NOWAIT);
525 			}
526 			if (status != RDMA_SUCCESS) {
527 				DTRACE_PROBE1(
528 				    krpc__i__xdrrdma_getblk_readfailed,
529 				    int, status);
530 				retval = FALSE;
531 			}
532 
533 			cle = cle->c_next;
534 
535 		}
536 
537 		/*
538 		 * sync the memory for cpu
539 		 */
540 		cl = *cls;
541 		cl.c_next = NULL;
542 		cl.c_len = cur_offset;
543 		if (clist_syncmem(
544 		    xdrp->xp_conn, &cl, CLIST_REG_DST) != RDMA_SUCCESS) {
545 			retval = FALSE;
546 		}
547 out:
548 
549 		/*
550 		 * Deregister the chunks
551 		 */
552 		cle = cls;
553 		while (actual_segments != 0) {
554 			cl = *cle;
555 			cl.c_next = NULL;
556 
557 			cl.c_regtype = CLIST_REG_DST;
558 			(void) clist_deregister(xdrp->xp_conn, &cl);
559 
560 			cle = cle->c_next;
561 			actual_segments--;
562 		}
563 
564 		if (alen) {
565 			cle = *(xdrp->xp_rcl_next);
566 			cle->w.c_saddr =
567 			    (uint64)(uintptr_t)cle->w.c_saddr + cle->c_len;
568 			cle->c_len = alen - cle->c_len;
569 		}
570 
571 		return (retval);
572 	}
573 
574 	if ((xdrs->x_handy -= len) < 0)
575 		return (FALSE);
576 
577 	bcopy(xdrp->xp_offp, addr, len);
578 
579 	xdrp->xp_offp += len;
580 
581 	if (xdrp->xp_off != 0)
582 		xdrp->xp_off += len;
583 
584 	return (TRUE);
585 }
586 
587 /*
588  * ENCODE some bytes into an XDR stream xp_min_chunk = 0, means the stream of
589  * bytes contain no chunks to seperate out, and if the bytes do not fit in
590  * the supplied buffer, grow the buffer and free the old buffer.
591  */
592 static	bool_t
593 xdrrdma_putbytes(XDR *xdrs, caddr_t addr, int len)
594 {
595 	xrdma_private_t	*xdrp = (xrdma_private_t *)(xdrs->x_private);
596 	/*
597 	 * Is this stream accepting chunks?
598 	 * If so, does the either of the two following conditions exist?
599 	 * - length of bytes to encode is greater than the min chunk size?
600 	 * - remaining space in this stream is shorter than length of
601 	 *   bytes to encode?
602 	 *
603 	 * If the above exists, then create a chunk for this encoding
604 	 * and save the addresses, etc.
605 	 */
606 	if (xdrp->xp_flags & XDR_RDMA_CHUNK &&
607 	    ((xdrp->xp_min_chunk != 0 &&
608 	    len >= xdrp->xp_min_chunk) ||
609 	    (xdrs->x_handy - len  < 0))) {
610 		struct clist	*cle;
611 		int		offset = xdrp->xp_offp - xdrs->x_base;
612 
613 		cle = clist_alloc();
614 		cle->c_xdroff = offset;
615 		cle->c_len = len;
616 		cle->w.c_saddr = (uint64)(uintptr_t)addr;
617 		cle->c_next = NULL;
618 
619 		*(xdrp->xp_rcl_next) = cle;
620 		xdrp->xp_rcl_next = &(cle->c_next);
621 
622 		return (TRUE);
623 	}
624 	/* Is there enough space to encode what is left? */
625 	if ((xdrs->x_handy -= len) < 0) {
626 		return (FALSE);
627 	}
628 	bcopy(addr, xdrp->xp_offp, len);
629 	xdrp->xp_offp += len;
630 
631 	return (TRUE);
632 }
633 
634 uint_t
635 xdrrdma_getpos(XDR *xdrs)
636 {
637 	xrdma_private_t *xdrp = (xrdma_private_t *)(xdrs->x_private);
638 
639 	return ((uint_t)((uintptr_t)xdrp->xp_offp - (uintptr_t)xdrs->x_base));
640 }
641 
642 bool_t
643 xdrrdma_setpos(XDR *xdrs, uint_t pos)
644 {
645 	xrdma_private_t	*xdrp = (xrdma_private_t *)(xdrs->x_private);
646 
647 	caddr_t		newaddr = xdrs->x_base + pos;
648 	caddr_t		lastaddr = xdrp->xp_offp + xdrs->x_handy;
649 	ptrdiff_t	diff;
650 
651 	if (newaddr > lastaddr)
652 		return (FALSE);
653 
654 	xdrp->xp_offp = newaddr;
655 	diff = lastaddr - newaddr;
656 	xdrs->x_handy = (int)diff;
657 
658 	return (TRUE);
659 }
660 
661 /* ARGSUSED */
662 static rpc_inline_t *
663 xdrrdma_inline(XDR *xdrs, int len)
664 {
665 	rpc_inline_t	*buf = NULL;
666 	xrdma_private_t	*xdrp = (xrdma_private_t *)(xdrs->x_private);
667 	struct clist	*cle = *(xdrp->xp_rcl_next);
668 
669 	if (xdrs->x_op == XDR_DECODE) {
670 		/*
671 		 * Since chunks aren't in-line, check to see whether there is
672 		 * a chunk in the inline range.
673 		 */
674 		if (cle != NULL &&
675 		    cle->c_xdroff <= (xdrp->xp_offp - xdrs->x_base + len))
676 			return (NULL);
677 	}
678 
679 	/* LINTED pointer alignment */
680 	buf = (rpc_inline_t *)xdrp->xp_offp;
681 	if (!IS_P2ALIGNED(buf, sizeof (int32_t)))
682 		return (NULL);
683 
684 	if ((xdrs->x_handy < len) || (xdrp->xp_min_chunk != 0 &&
685 	    len >= xdrp->xp_min_chunk)) {
686 		return (NULL);
687 	} else {
688 		xdrs->x_handy -= len;
689 		xdrp->xp_offp += len;
690 		return (buf);
691 	}
692 }
693 
694 static	bool_t
695 xdrrdma_control(XDR *xdrs, int request, void *info)
696 {
697 	int32_t		*int32p;
698 	int		len, i;
699 	uint_t		in_flags;
700 	xrdma_private_t	*xdrp = (xrdma_private_t *)(xdrs->x_private);
701 	rdma_chunkinfo_t *rcip = NULL;
702 	rdma_wlist_conn_info_t *rwcip = NULL;
703 	rdma_chunkinfo_lengths_t *rcilp = NULL;
704 	struct uio *uiop;
705 	struct clist	*rwl = NULL;
706 	struct clist	*prev = NULL;
707 
708 	switch (request) {
709 	case XDR_PEEK:
710 		/*
711 		 * Return the next 4 byte unit in the XDR stream.
712 		 */
713 		if (xdrs->x_handy < sizeof (int32_t))
714 			return (FALSE);
715 
716 		int32p = (int32_t *)info;
717 		*int32p = (int32_t)ntohl((uint32_t)
718 		    (*((int32_t *)(xdrp->xp_offp))));
719 
720 		return (TRUE);
721 
722 	case XDR_SKIPBYTES:
723 		/*
724 		 * Skip the next N bytes in the XDR stream.
725 		 */
726 		int32p = (int32_t *)info;
727 		len = RNDUP((int)(*int32p));
728 		if ((xdrs->x_handy -= len) < 0)
729 			return (FALSE);
730 		xdrp->xp_offp += len;
731 
732 		return (TRUE);
733 
734 	case XDR_RDMA_SET_FLAGS:
735 		/*
736 		 * Set the flags provided in the *info in xp_flags for rdma
737 		 * xdr stream control.
738 		 */
739 		int32p = (int32_t *)info;
740 		in_flags = (uint_t)(*int32p);
741 
742 		xdrp->xp_flags |= in_flags;
743 		return (TRUE);
744 
745 	case XDR_RDMA_GET_FLAGS:
746 		/*
747 		 * Get the flags provided in xp_flags return through *info
748 		 */
749 		int32p = (int32_t *)info;
750 
751 		*int32p = (int32_t)xdrp->xp_flags;
752 		return (TRUE);
753 
754 	case XDR_RDMA_GET_CHUNK_LEN:
755 		rcilp = (rdma_chunkinfo_lengths_t *)info;
756 		rcilp->rcil_len = xdrp->xp_reply_chunk_len;
757 		rcilp->rcil_len_alt = xdrp->xp_reply_chunk_len_alt;
758 
759 		return (TRUE);
760 
761 	case XDR_RDMA_ADD_CHUNK:
762 		/*
763 		 * Store wlist information
764 		 */
765 
766 		rcip = (rdma_chunkinfo_t *)info;
767 
768 		switch (rcip->rci_type) {
769 		case RCI_WRITE_UIO_CHUNK:
770 			xdrp->xp_reply_chunk_len_alt += rcip->rci_len;
771 
772 			if (rcip->rci_len < xdrp->xp_min_chunk) {
773 				xdrp->xp_wcl = NULL;
774 				*(rcip->rci_clpp) = NULL;
775 				return (TRUE);
776 			}
777 			uiop = rcip->rci_a.rci_uiop;
778 
779 			for (i = 0; i < uiop->uio_iovcnt; i++) {
780 				rwl = clist_alloc();
781 				rwl->c_len = uiop->uio_iov[i].iov_len;
782 				rwl->u.c_daddr =
783 				    (uint64)(uintptr_t)
784 				    (uiop->uio_iov[i].iov_base);
785 				/*
786 				 * if userspace address, put adspace ptr in
787 				 * clist. If not, then do nothing since it's
788 				 * already set to NULL (from kmem_zalloc)
789 				 */
790 				if (uiop->uio_segflg == UIO_USERSPACE) {
791 					rwl->c_adspc = ttoproc(curthread)->p_as;
792 				}
793 
794 				if (prev == NULL)
795 					prev = rwl;
796 				else {
797 					prev->c_next = rwl;
798 					prev = rwl;
799 				}
800 			}
801 
802 			rwl->c_next = NULL;
803 			xdrp->xp_wcl = rwl;
804 			*(rcip->rci_clpp) = rwl;
805 
806 			break;
807 
808 		case RCI_WRITE_ADDR_CHUNK:
809 			rwl = clist_alloc();
810 
811 			rwl->c_len = rcip->rci_len;
812 			rwl->u.c_daddr3 = rcip->rci_a.rci_addr;
813 			rwl->c_next = NULL;
814 			xdrp->xp_reply_chunk_len_alt += rcip->rci_len;
815 
816 			xdrp->xp_wcl = rwl;
817 			*(rcip->rci_clpp) = rwl;
818 
819 			break;
820 
821 		case RCI_REPLY_CHUNK:
822 			xdrp->xp_reply_chunk_len += rcip->rci_len;
823 			break;
824 		}
825 		return (TRUE);
826 
827 	case XDR_RDMA_GET_WLIST:
828 		*((struct clist **)info) = xdrp->xp_wcl;
829 		return (TRUE);
830 
831 	case XDR_RDMA_SET_WLIST:
832 		xdrp->xp_wcl = (struct clist *)info;
833 		return (TRUE);
834 
835 	case XDR_RDMA_GET_RLIST:
836 		*((struct clist **)info) = xdrp->xp_rcl;
837 		return (TRUE);
838 
839 	case XDR_RDMA_GET_WCINFO:
840 		rwcip = (rdma_wlist_conn_info_t *)info;
841 
842 		rwcip->rwci_wlist = xdrp->xp_wcl;
843 		rwcip->rwci_conn = xdrp->xp_conn;
844 
845 		return (TRUE);
846 
847 	default:
848 		return (FALSE);
849 	}
850 }
851 
852 bool_t xdr_do_clist(XDR *, clist **);
853 
854 /*
855  * Not all fields in struct clist are interesting to the RPC over RDMA
856  * protocol. Only XDR the interesting fields.
857  */
858 bool_t
859 xdr_clist(XDR *xdrs, clist *objp)
860 {
861 	if (!xdr_uint32(xdrs, &objp->c_xdroff))
862 		return (FALSE);
863 	if (!xdr_uint32(xdrs, &objp->c_smemhandle.mrc_rmr))
864 		return (FALSE);
865 	if (!xdr_uint32(xdrs, &objp->c_len))
866 		return (FALSE);
867 	if (!xdr_uint64(xdrs, &objp->w.c_saddr))
868 		return (FALSE);
869 	if (!xdr_do_clist(xdrs, &objp->c_next))
870 		return (FALSE);
871 	return (TRUE);
872 }
873 
874 /*
875  * The following two functions are forms of xdr_pointer()
876  * and xdr_reference(). Since the generic versions just
877  * kmem_alloc() a new clist, we actually want to use the
878  * rdma_clist kmem_cache.
879  */
880 
881 /*
882  * Generate or free a clist structure from the
883  * kmem_cache "rdma_clist"
884  */
885 bool_t
886 xdr_ref_clist(XDR *xdrs, caddr_t *pp)
887 {
888 	caddr_t loc = *pp;
889 	bool_t stat;
890 
891 	if (loc == NULL) {
892 		switch (xdrs->x_op) {
893 		case XDR_FREE:
894 			return (TRUE);
895 
896 		case XDR_DECODE:
897 			*pp = loc = (caddr_t)clist_alloc();
898 			break;
899 
900 		case XDR_ENCODE:
901 			ASSERT(loc);
902 			break;
903 		}
904 	}
905 
906 	stat = xdr_clist(xdrs, (struct clist *)loc);
907 
908 	if (xdrs->x_op == XDR_FREE) {
909 		kmem_cache_free(clist_cache, loc);
910 		*pp = NULL;
911 	}
912 	return (stat);
913 }
914 
915 /*
916  * XDR a pointer to a possibly recursive clist. This differs
917  * with xdr_reference in that it can serialize/deserialiaze
918  * trees correctly.
919  *
920  *  What is sent is actually a union:
921  *
922  *  union object_pointer switch (boolean b) {
923  *  case TRUE: object_data data;
924  *  case FALSE: void nothing;
925  *  }
926  *
927  * > objpp: Pointer to the pointer to the object.
928  *
929  */
930 
931 bool_t
932 xdr_do_clist(XDR *xdrs, clist **objpp)
933 {
934 	bool_t more_data;
935 
936 	more_data = (*objpp != NULL);
937 	if (!xdr_bool(xdrs, &more_data))
938 		return (FALSE);
939 	if (!more_data) {
940 		*objpp = NULL;
941 		return (TRUE);
942 	}
943 	return (xdr_ref_clist(xdrs, (caddr_t *)objpp));
944 }
945 
946 uint_t
947 xdr_getbufsize(XDR *xdrs)
948 {
949 	xrdma_private_t *xdrp = (xrdma_private_t *)(xdrs->x_private);
950 
951 	return ((uint_t)xdrp->xp_buf_size);
952 }
953 
954 /* ARGSUSED */
955 bool_t
956 xdr_encode_rlist_svc(XDR *xdrs, clist *rlist)
957 {
958 	bool_t	vfalse = FALSE;
959 
960 	ASSERT(rlist == NULL);
961 	return (xdr_bool(xdrs, &vfalse));
962 }
963 
964 bool_t
965 xdr_encode_wlist(XDR *xdrs, clist *w)
966 {
967 	bool_t		vfalse = FALSE, vtrue = TRUE;
968 	int		i;
969 	uint_t		num_segment = 0;
970 	struct clist	*cl;
971 
972 	/* does a wlist exist? */
973 	if (w == NULL) {
974 		return (xdr_bool(xdrs, &vfalse));
975 	}
976 	/* Encode N consecutive segments, 1, N, HLOO, ..., HLOO, 0 */
977 	if (!xdr_bool(xdrs, &vtrue))
978 		return (FALSE);
979 
980 	for (cl = w; cl != NULL; cl = cl->c_next) {
981 		num_segment++;
982 	}
983 
984 	if (!xdr_uint32(xdrs, &num_segment))
985 		return (FALSE);
986 	for (i = 0; i < num_segment; i++) {
987 
988 		DTRACE_PROBE1(krpc__i__xdr_encode_wlist_len, uint_t, w->c_len);
989 
990 		if (!xdr_uint32(xdrs, &w->c_dmemhandle.mrc_rmr))
991 			return (FALSE);
992 
993 		if (!xdr_uint32(xdrs, &w->c_len))
994 			return (FALSE);
995 
996 		if (!xdr_uint64(xdrs, &w->u.c_daddr))
997 			return (FALSE);
998 
999 		w = w->c_next;
1000 	}
1001 
1002 	if (!xdr_bool(xdrs, &vfalse))
1003 		return (FALSE);
1004 
1005 	return (TRUE);
1006 }
1007 
1008 
1009 /*
1010  * Conditionally decode a RDMA WRITE chunk list from XDR stream.
1011  *
1012  * If the next boolean in the XDR stream is false there is no
1013  * RDMA WRITE chunk list present. Otherwise iterate over the
1014  * array and for each entry: allocate a struct clist and decode.
1015  * Pass back an indication via wlist_exists if we have seen a
1016  * RDMA WRITE chunk list.
1017  */
1018 bool_t
1019 xdr_decode_wlist(XDR *xdrs, struct clist **w, bool_t *wlist_exists)
1020 {
1021 	struct clist	*tmp;
1022 	bool_t		more = FALSE;
1023 	uint32_t	seg_array_len;
1024 	uint32_t	i;
1025 
1026 	if (!xdr_bool(xdrs, &more))
1027 		return (FALSE);
1028 
1029 	/* is there a wlist? */
1030 	if (more == FALSE) {
1031 		*wlist_exists = FALSE;
1032 		return (TRUE);
1033 	}
1034 	*wlist_exists = TRUE;
1035 
1036 	if (!xdr_uint32(xdrs, &seg_array_len))
1037 		return (FALSE);
1038 
1039 	tmp = *w = clist_alloc();
1040 	for (i = 0; i < seg_array_len; i++) {
1041 
1042 		if (!xdr_uint32(xdrs, &tmp->c_dmemhandle.mrc_rmr))
1043 			return (FALSE);
1044 		if (!xdr_uint32(xdrs, &tmp->c_len))
1045 			return (FALSE);
1046 
1047 		DTRACE_PROBE1(krpc__i__xdr_decode_wlist_len,
1048 		    uint_t, tmp->c_len);
1049 
1050 		if (!xdr_uint64(xdrs, &tmp->u.c_daddr))
1051 			return (FALSE);
1052 		if (i < seg_array_len - 1) {
1053 			tmp->c_next = clist_alloc();
1054 			tmp = tmp->c_next;
1055 		} else {
1056 			tmp->c_next = NULL;
1057 		}
1058 	}
1059 
1060 	more = FALSE;
1061 	if (!xdr_bool(xdrs, &more))
1062 		return (FALSE);
1063 
1064 	return (TRUE);
1065 }
1066 
1067 /*
1068  * Server side RDMA WRITE list decode.
1069  * XDR context is memory ops
1070  */
1071 bool_t
1072 xdr_decode_wlist_svc(XDR *xdrs, struct clist **wclp, bool_t *wwl,
1073     uint32_t *total_length, CONN *conn)
1074 {
1075 	struct clist	*first, *ncl;
1076 	char		*memp;
1077 	uint32_t	num_wclist;
1078 	uint32_t	wcl_length = 0;
1079 	uint32_t	i;
1080 	bool_t		more = FALSE;
1081 
1082 	*wclp = NULL;
1083 	*wwl = FALSE;
1084 	*total_length = 0;
1085 
1086 	if (!xdr_bool(xdrs, &more)) {
1087 		return (FALSE);
1088 	}
1089 
1090 	if (more == FALSE) {
1091 		return (TRUE);
1092 	}
1093 
1094 	*wwl = TRUE;
1095 
1096 	if (!xdr_uint32(xdrs, &num_wclist)) {
1097 		DTRACE_PROBE(krpc__e__xdrrdma__wlistsvc__listlength);
1098 		return (FALSE);
1099 	}
1100 
1101 	first = ncl = clist_alloc();
1102 
1103 	for (i = 0; i < num_wclist; i++) {
1104 
1105 		if (!xdr_uint32(xdrs, &ncl->c_dmemhandle.mrc_rmr))
1106 			goto err_out;
1107 		if (!xdr_uint32(xdrs, &ncl->c_len))
1108 			goto err_out;
1109 		if (!xdr_uint64(xdrs, &ncl->u.c_daddr))
1110 			goto err_out;
1111 
1112 		if (ncl->c_len > MAX_SVC_XFER_SIZE) {
1113 			DTRACE_PROBE(
1114 			    krpc__e__xdrrdma__wlistsvc__chunklist_toobig);
1115 			ncl->c_len = MAX_SVC_XFER_SIZE;
1116 		}
1117 
1118 		DTRACE_PROBE1(krpc__i__xdr_decode_wlist_svc_len,
1119 		    uint_t, ncl->c_len);
1120 
1121 		wcl_length += ncl->c_len;
1122 
1123 		if (i < num_wclist - 1) {
1124 			ncl->c_next = clist_alloc();
1125 			ncl = ncl->c_next;
1126 		}
1127 	}
1128 
1129 	if (!xdr_bool(xdrs, &more))
1130 		goto err_out;
1131 
1132 	first->rb_longbuf.type = RDMA_LONG_BUFFER;
1133 	first->rb_longbuf.len =
1134 	    wcl_length > WCL_BUF_LEN ? wcl_length : WCL_BUF_LEN;
1135 
1136 	if (rdma_buf_alloc(conn, &first->rb_longbuf)) {
1137 		clist_free(first);
1138 		return (FALSE);
1139 	}
1140 
1141 	memp = first->rb_longbuf.addr;
1142 
1143 	ncl = first;
1144 	for (i = 0; i < num_wclist; i++) {
1145 		ncl->w.c_saddr3 = (caddr_t)memp;
1146 		memp += ncl->c_len;
1147 		ncl = ncl->c_next;
1148 	}
1149 
1150 	*wclp = first;
1151 	*total_length = wcl_length;
1152 	return (TRUE);
1153 
1154 err_out:
1155 	clist_free(first);
1156 	return (FALSE);
1157 }
1158 
1159 /*
1160  * XDR decode the long reply write chunk.
1161  */
1162 bool_t
1163 xdr_decode_reply_wchunk(XDR *xdrs, struct clist **clist)
1164 {
1165 	bool_t		have_rchunk = FALSE;
1166 	struct clist	*first = NULL, *ncl = NULL;
1167 	uint32_t	num_wclist;
1168 	uint32_t	i;
1169 
1170 	if (!xdr_bool(xdrs, &have_rchunk))
1171 		return (FALSE);
1172 
1173 	if (have_rchunk == FALSE)
1174 		return (TRUE);
1175 
1176 	if (!xdr_uint32(xdrs, &num_wclist)) {
1177 		DTRACE_PROBE(krpc__e__xdrrdma__replywchunk__listlength);
1178 		return (FALSE);
1179 	}
1180 
1181 	if (num_wclist == 0) {
1182 		return (FALSE);
1183 	}
1184 
1185 	first = ncl = clist_alloc();
1186 
1187 	for (i = 0; i < num_wclist; i++) {
1188 
1189 		if (i > 0) {
1190 			ncl->c_next = clist_alloc();
1191 			ncl = ncl->c_next;
1192 		}
1193 
1194 		if (!xdr_uint32(xdrs, &ncl->c_dmemhandle.mrc_rmr))
1195 			goto err_out;
1196 		if (!xdr_uint32(xdrs, &ncl->c_len))
1197 			goto err_out;
1198 		if (!xdr_uint64(xdrs, &ncl->u.c_daddr))
1199 			goto err_out;
1200 
1201 		if (ncl->c_len > MAX_SVC_XFER_SIZE) {
1202 			DTRACE_PROBE(
1203 			    krpc__e__xdrrdma__replywchunk__chunklist_toobig);
1204 			ncl->c_len = MAX_SVC_XFER_SIZE;
1205 		}
1206 		if (!(ncl->c_dmemhandle.mrc_rmr &&
1207 		    (ncl->c_len > 0) && ncl->u.c_daddr))
1208 			DTRACE_PROBE(
1209 			    krpc__e__xdrrdma__replywchunk__invalid_segaddr);
1210 
1211 		DTRACE_PROBE1(krpc__i__xdr_decode_reply_wchunk_c_len,
1212 		    uint32_t, ncl->c_len);
1213 
1214 	}
1215 	*clist = first;
1216 	return (TRUE);
1217 
1218 err_out:
1219 	clist_free(first);
1220 	return (FALSE);
1221 }
1222 
1223 
1224 bool_t
1225 xdr_encode_reply_wchunk(XDR *xdrs,
1226     struct clist *cl_longreply, uint32_t seg_array_len)
1227 {
1228 	int		i;
1229 	bool_t		long_reply_exists = TRUE;
1230 	uint32_t	length;
1231 	uint64		offset;
1232 
1233 	if (seg_array_len > 0) {
1234 		if (!xdr_bool(xdrs, &long_reply_exists))
1235 			return (FALSE);
1236 		if (!xdr_uint32(xdrs, &seg_array_len))
1237 			return (FALSE);
1238 
1239 		for (i = 0; i < seg_array_len; i++) {
1240 			if (!cl_longreply)
1241 				return (FALSE);
1242 			length = cl_longreply->c_len;
1243 			offset = (uint64) cl_longreply->u.c_daddr;
1244 
1245 			DTRACE_PROBE1(
1246 			    krpc__i__xdr_encode_reply_wchunk_c_len,
1247 			    uint32_t, length);
1248 
1249 			if (!xdr_uint32(xdrs,
1250 			    &cl_longreply->c_dmemhandle.mrc_rmr))
1251 				return (FALSE);
1252 			if (!xdr_uint32(xdrs, &length))
1253 				return (FALSE);
1254 			if (!xdr_uint64(xdrs, &offset))
1255 				return (FALSE);
1256 			cl_longreply = cl_longreply->c_next;
1257 		}
1258 	} else {
1259 		long_reply_exists = FALSE;
1260 		if (!xdr_bool(xdrs, &long_reply_exists))
1261 			return (FALSE);
1262 	}
1263 	return (TRUE);
1264 }
1265 bool_t
1266 xdrrdma_read_from_client(struct clist *rlist, CONN **conn, uint_t count)
1267 {
1268 	struct clist	*rdclist;
1269 	struct clist	cl;
1270 	uint_t		total_len = 0;
1271 	uint32_t	status;
1272 	bool_t		retval = TRUE;
1273 
1274 	rlist->rb_longbuf.type = RDMA_LONG_BUFFER;
1275 	rlist->rb_longbuf.len =
1276 	    count > RCL_BUF_LEN ? count : RCL_BUF_LEN;
1277 
1278 	if (rdma_buf_alloc(*conn, &rlist->rb_longbuf)) {
1279 		return (FALSE);
1280 	}
1281 
1282 	/*
1283 	 * The entire buffer is registered with the first chunk.
1284 	 * Later chunks will use the same registered memory handle.
1285 	 */
1286 
1287 	cl = *rlist;
1288 	cl.c_next = NULL;
1289 	if (clist_register(*conn, &cl, CLIST_REG_DST) != RDMA_SUCCESS) {
1290 		rdma_buf_free(*conn, &rlist->rb_longbuf);
1291 		DTRACE_PROBE(
1292 		    krpc__e__xdrrdma__readfromclient__clist__reg);
1293 		return (FALSE);
1294 	}
1295 
1296 	rlist->c_regtype = CLIST_REG_DST;
1297 	rlist->c_dmemhandle = cl.c_dmemhandle;
1298 	rlist->c_dsynchandle = cl.c_dsynchandle;
1299 
1300 	for (rdclist = rlist;
1301 	    rdclist != NULL; rdclist = rdclist->c_next) {
1302 		total_len += rdclist->c_len;
1303 #if (defined(OBJ32)||defined(DEBUG32))
1304 		rdclist->u.c_daddr3 =
1305 		    (caddr_t)((char *)rlist->rb_longbuf.addr +
1306 		    (uint32) rdclist->u.c_daddr3);
1307 #else
1308 		rdclist->u.c_daddr3 =
1309 		    (caddr_t)((char *)rlist->rb_longbuf.addr +
1310 		    (uint64) rdclist->u.c_daddr);
1311 
1312 #endif
1313 		cl = (*rdclist);
1314 		cl.c_next = NULL;
1315 
1316 		/*
1317 		 * Use the same memory handle for all the chunks
1318 		 */
1319 		cl.c_dmemhandle = rlist->c_dmemhandle;
1320 		cl.c_dsynchandle = rlist->c_dsynchandle;
1321 
1322 
1323 		DTRACE_PROBE1(krpc__i__xdrrdma__readfromclient__buflen,
1324 		    int, rdclist->c_len);
1325 
1326 		/*
1327 		 * Now read the chunk in
1328 		 */
1329 		if (rdclist->c_next == NULL) {
1330 			status = RDMA_READ(*conn, &cl, WAIT);
1331 		} else {
1332 			status = RDMA_READ(*conn, &cl, NOWAIT);
1333 		}
1334 		if (status != RDMA_SUCCESS) {
1335 			DTRACE_PROBE(
1336 			    krpc__e__xdrrdma__readfromclient__readfailed);
1337 			rdma_buf_free(*conn, &rlist->rb_longbuf);
1338 			return (FALSE);
1339 		}
1340 	}
1341 
1342 	cl = (*rlist);
1343 	cl.c_next = NULL;
1344 	cl.c_len = total_len;
1345 	if (clist_syncmem(*conn, &cl, CLIST_REG_DST) != RDMA_SUCCESS) {
1346 		retval = FALSE;
1347 	}
1348 	return (retval);
1349 }
1350 
1351 bool_t
1352 xdrrdma_free_clist(CONN *conn, struct clist *clp)
1353 {
1354 	rdma_buf_free(conn, &clp->rb_longbuf);
1355 	clist_free(clp);
1356 	return (TRUE);
1357 }
1358 
1359 bool_t
1360 xdrrdma_send_read_data(XDR *xdrs, uint_t data_len, struct clist *wcl)
1361 {
1362 	int status;
1363 	xrdma_private_t	*xdrp = (xrdma_private_t *)(xdrs->x_private);
1364 	struct xdr_ops *xops = xdrrdma_xops();
1365 	struct clist *tcl, *wrcl, *cl;
1366 	struct clist fcl;
1367 	int rndup_present, rnduplen;
1368 
1369 	rndup_present = 0;
1370 	wrcl = NULL;
1371 
1372 	/* caller is doing a sizeof */
1373 	if (xdrs->x_ops != &xdrrdma_ops || xdrs->x_ops == xops)
1374 		return (TRUE);
1375 
1376 	/* copy of the first chunk */
1377 	fcl = *wcl;
1378 	fcl.c_next = NULL;
1379 
1380 	/*
1381 	 * The entire buffer is registered with the first chunk.
1382 	 * Later chunks will use the same registered memory handle.
1383 	 */
1384 
1385 	status = clist_register(xdrp->xp_conn, &fcl, CLIST_REG_SOURCE);
1386 	if (status != RDMA_SUCCESS) {
1387 		return (FALSE);
1388 	}
1389 
1390 	wcl->c_regtype = CLIST_REG_SOURCE;
1391 	wcl->c_smemhandle = fcl.c_smemhandle;
1392 	wcl->c_ssynchandle = fcl.c_ssynchandle;
1393 
1394 	/*
1395 	 * Only transfer the read data ignoring any trailing
1396 	 * roundup chunks. A bit of work, but it saves an
1397 	 * unnecessary extra RDMA_WRITE containing only
1398 	 * roundup bytes.
1399 	 */
1400 
1401 	rnduplen = clist_len(wcl) - data_len;
1402 
1403 	if (rnduplen) {
1404 
1405 		tcl = wcl->c_next;
1406 
1407 		/*
1408 		 * Check if there is a trailing roundup chunk
1409 		 */
1410 		while (tcl) {
1411 			if ((tcl->c_next == NULL) && (tcl->c_len == rnduplen)) {
1412 				rndup_present = 1;
1413 				break;
1414 			}
1415 			tcl = tcl->c_next;
1416 		}
1417 
1418 		/*
1419 		 * Make a copy chunk list skipping the last chunk
1420 		 */
1421 		if (rndup_present) {
1422 			cl = wcl;
1423 			tcl = NULL;
1424 			while (cl) {
1425 				if (tcl == NULL) {
1426 					tcl = clist_alloc();
1427 					wrcl = tcl;
1428 				} else {
1429 					tcl->c_next = clist_alloc();
1430 					tcl = tcl->c_next;
1431 				}
1432 
1433 				*tcl = *cl;
1434 				cl = cl->c_next;
1435 				/* last chunk */
1436 				if (cl->c_next == NULL)
1437 					break;
1438 			}
1439 			tcl->c_next = NULL;
1440 		}
1441 	}
1442 
1443 	if (wrcl == NULL) {
1444 		/* No roundup chunks */
1445 		wrcl = wcl;
1446 	}
1447 
1448 	/*
1449 	 * Set the registered memory handles for the
1450 	 * rest of the chunks same as the first chunk.
1451 	 */
1452 	tcl = wrcl->c_next;
1453 	while (tcl) {
1454 		tcl->c_smemhandle = fcl.c_smemhandle;
1455 		tcl->c_ssynchandle = fcl.c_ssynchandle;
1456 		tcl = tcl->c_next;
1457 	}
1458 
1459 	/*
1460 	 * Sync the total len beginning from the first chunk.
1461 	 */
1462 	fcl.c_len = clist_len(wrcl);
1463 	status = clist_syncmem(xdrp->xp_conn, &fcl, CLIST_REG_SOURCE);
1464 	if (status != RDMA_SUCCESS) {
1465 		return (FALSE);
1466 	}
1467 
1468 	status = RDMA_WRITE(xdrp->xp_conn, wrcl, WAIT);
1469 
1470 	if (rndup_present)
1471 		clist_free(wrcl);
1472 
1473 	if (status != RDMA_SUCCESS) {
1474 		return (FALSE);
1475 	}
1476 
1477 	return (TRUE);
1478 }
1479 
1480 
1481 /*
1482  * Reads one chunk at a time
1483  */
1484 
1485 static bool_t
1486 xdrrdma_read_a_chunk(XDR *xdrs, CONN **conn)
1487 {
1488 	int status;
1489 	int32_t len = 0;
1490 	xrdma_private_t	*xdrp = (xrdma_private_t *)(xdrs->x_private);
1491 	struct clist *cle = *(xdrp->xp_rcl_next);
1492 	struct clist *rclp = xdrp->xp_rcl;
1493 	struct clist *clp;
1494 
1495 	/*
1496 	 * len is used later to decide xdr offset in
1497 	 * the chunk factoring any 4-byte XDR alignment
1498 	 * (See read chunk example top of this file)
1499 	 */
1500 	while (rclp != cle) {
1501 		len += rclp->c_len;
1502 		rclp = rclp->c_next;
1503 	}
1504 
1505 	len = RNDUP(len) - len;
1506 
1507 	ASSERT(xdrs->x_handy <= 0);
1508 
1509 	/*
1510 	 * If this is the first chunk to contain the RPC
1511 	 * message set xp_off to the xdr offset of the
1512 	 * inline message.
1513 	 */
1514 	if (xdrp->xp_off == 0)
1515 		xdrp->xp_off = (xdrp->xp_offp - xdrs->x_base);
1516 
1517 	if (cle == NULL || (cle->c_xdroff != xdrp->xp_off))
1518 		return (FALSE);
1519 
1520 	/*
1521 	 * Make a copy of the chunk to read from client.
1522 	 * Chunks are read on demand, so read only one
1523 	 * for now.
1524 	 */
1525 
1526 	rclp = clist_alloc();
1527 	*rclp = *cle;
1528 	rclp->c_next = NULL;
1529 
1530 	xdrp->xp_rcl_next = &cle->c_next;
1531 
1532 	/*
1533 	 * If there is a roundup present, then skip those
1534 	 * bytes when reading.
1535 	 */
1536 	if (len) {
1537 		rclp->w.c_saddr =
1538 		    (uint64)(uintptr_t)rclp->w.c_saddr + len;
1539 			rclp->c_len = rclp->c_len - len;
1540 	}
1541 
1542 	status = xdrrdma_read_from_client(rclp, conn, rclp->c_len);
1543 
1544 	if (status == FALSE) {
1545 		clist_free(rclp);
1546 		return (status);
1547 	}
1548 
1549 	xdrp->xp_offp = rclp->rb_longbuf.addr;
1550 	xdrs->x_base = xdrp->xp_offp;
1551 	xdrs->x_handy = rclp->c_len;
1552 
1553 	/*
1554 	 * This copy of read chunks containing the XDR
1555 	 * message is freed later in xdrrdma_destroy()
1556 	 */
1557 
1558 	if (xdrp->xp_rcl_xdr) {
1559 		/* Add the chunk to end of the list */
1560 		clp = xdrp->xp_rcl_xdr;
1561 		while (clp->c_next != NULL)
1562 			clp = clp->c_next;
1563 		clp->c_next = rclp;
1564 	} else {
1565 		xdrp->xp_rcl_xdr = rclp;
1566 	}
1567 	return (TRUE);
1568 }
1569 
1570 static void
1571 xdrrdma_free_xdr_chunks(CONN *conn, struct clist *xdr_rcl)
1572 {
1573 	struct clist *cl;
1574 
1575 	(void) clist_deregister(conn, xdr_rcl);
1576 
1577 	/*
1578 	 * Read chunks containing parts XDR message are
1579 	 * special: in case of multiple chunks each has
1580 	 * its own buffer.
1581 	 */
1582 
1583 	cl = xdr_rcl;
1584 	while (cl) {
1585 		rdma_buf_free(conn, &cl->rb_longbuf);
1586 		cl = cl->c_next;
1587 	}
1588 
1589 	clist_free(xdr_rcl);
1590 }
1591