sys/kern/subr_sglist.c

66 #define	SGLIST_SAVE(sg, sgsave) do {					\
67 	(sgsave).sg_nseg = (sg)->sg_nseg;				\
69 		(sgsave).ss_len = (sg)->sg_segs[(sgsave).sg_nseg - 1].ss_len; \
74 #define	SGLIST_RESTORE(sg, sgsave) do {					\
75 	(sg)->sg_nseg = (sgsave).sg_nseg;				\
77 		(sg)->sg_segs[(sgsave).sg_nseg - 1].ss_len = (sgsave).ss_len; \
81  * Append a single (paddr, len) to a sglist.  sg is the list and ss is
86 _sglist_append_range(struct sglist *sg, struct sglist_seg **ssp,
95 		if (sg->sg_nseg == sg->sg_maxseg)
100 		sg->sg_nseg++;
111 _sglist_append_buf(struct sglist *sg, void *buf, size_t len, pmap_t pmap,
133 	if (sg->sg_nseg == 0) {
134 		ss = sg->sg_segs;
137 		sg->sg_nseg = 1;
139 		ss = &sg->sg_segs[sg->sg_nseg - 1];
140 		error = _sglist_append_range(sg, &ss, paddr, seglen);
155 		error = _sglist_append_range(sg, &ss, paddr, seglen);
286 	struct sglist *sg;
288 	sg = malloc(sizeof(struct sglist) + nsegs * sizeof(struct sglist_seg),
290 	if (sg == NULL)
292 	sglist_init(sg, nsegs, (struct sglist_seg *)(sg + 1));
293 	return (sg);
300 sglist_free(struct sglist *sg)
303 	if (sg == NULL)
306 	if (refcount_release(&sg->sg_refs))
307 		free(sg, M_SGLIST);
316 sglist_append(struct sglist *sg, void *buf, size_t len)
321 	if (sg->sg_maxseg == 0)
323 	SGLIST_SAVE(sg, save);
324 	error = _sglist_append_buf(sg, buf, len, NULL, NULL);
326 		SGLIST_RESTORE(sg, save);
337 sglist_append_bio(struct sglist *sg, struct bio *bp)
342 		error = sglist_append(sg, bp->bio_data, bp->bio_bcount);
344 		error = sglist_append_vmpages(sg, bp->bio_ma,
354 sglist_append_phys(struct sglist *sg, vm_paddr_t paddr, size_t len)
360 	if (sg->sg_maxseg == 0)
365 	if (sg->sg_nseg == 0) {
366 		sg->sg_segs[0].ss_paddr = paddr;
367 		sg->sg_segs[0].ss_len = len;
368 		sg->sg_nseg = 1;
371 	ss = &sg->sg_segs[sg->sg_nseg - 1];
372 	SGLIST_SAVE(sg, save);
373 	error = _sglist_append_range(sg, &ss, paddr, len);
375 		SGLIST_RESTORE(sg, save);
384 sglist_append_mbuf_epg(struct sglist *sg, struct mbuf *m, size_t off,
403 			error = sglist_append(sg,
421 		error = sglist_append_phys(sg, paddr, seglen);
427 		error = sglist_append(sg,
441 sglist_append_mbuf(struct sglist *sg, struct mbuf *m0)
447 	if (sg->sg_maxseg == 0)
451 	SGLIST_SAVE(sg, save);
455 				error = sglist_append_mbuf_epg(sg, m,
458 				error = sglist_append(sg, m->m_data,
461 				SGLIST_RESTORE(sg, save);
475 sglist_append_vmpages(struct sglist *sg, vm_page_t *m, size_t pgoff,
484 	if (sg->sg_maxseg == 0)
489 	SGLIST_SAVE(sg, save);
491 	if (sg->sg_nseg == 0) {
493 		sg->sg_segs[0].ss_paddr = VM_PAGE_TO_PHYS(m[0]) + pgoff;
494 		sg->sg_segs[0].ss_len = seglen;
495 		sg->sg_nseg = 1;
500 	ss = &sg->sg_segs[sg->sg_nseg - 1];
504 		error = _sglist_append_range(sg, &ss, paddr, seglen);
506 			SGLIST_RESTORE(sg, save);
520 sglist_append_user(struct sglist *sg, void *buf, size_t len, struct thread *td)
525 	if (sg->sg_maxseg == 0)
527 	SGLIST_SAVE(sg, save);
528 	error = _sglist_append_buf(sg, buf, len,
531 		SGLIST_RESTORE(sg, save);
537  * the scatter/gather list 'sg'.  If there are insufficient segments,
541 sglist_append_sglist(struct sglist *sg, struct sglist *source, size_t offset,
549 	if (sg->sg_maxseg == 0 || length == 0)
551 	SGLIST_SAVE(sg, save);
553 	ss = &sg->sg_segs[sg->sg_nseg - 1];
562 		error = _sglist_append_range(sg, &ss,
574 		SGLIST_RESTORE(sg, save);
584 sglist_append_uio(struct sglist *sg, struct uio *uio)
592 	if (sg->sg_maxseg == 0)
606 	SGLIST_SAVE(sg, save);
614 			error = _sglist_append_buf(sg, iov[i].iov_base, minlen,
617 				SGLIST_RESTORE(sg, save);
632 sglist_consume_uio(struct sglist *sg, struct uio *uio, size_t resid)
639 	if (sg->sg_maxseg == 0)
665 		error = _sglist_append_buf(sg, iov->iov_base, len, pmap, &done);
684 	struct sglist *sg;
691 	sg = sglist_alloc(nsegs, mflags);
692 	if (sg == NULL)
694 	if (sglist_append(sg, buf, len) != 0) {
695 		sglist_free(sg);
698 	return (sg);
705 sglist_clone(struct sglist *sg, int mflags)
709 	if (sg == NULL)
711 	new = sglist_alloc(sg->sg_maxseg, mflags);
714 	new->sg_nseg = sg->sg_nseg;
715 	bcopy(sg->sg_segs, new->sg_segs, sizeof(struct sglist_seg) *
716 	    sg->sg_nseg);
725 sglist_length(struct sglist *sg)
731 	for (i = 0; i < sg->sg_nseg; i++)
732 		space += sg->sg_segs[i].ss_len;
757 	struct sglist *sg;
788 		sg = sglist_alloc(count, mflags);
789 		if (sg == NULL)
791 		*head = sg;
793 		sg = *head;
794 		if (sg->sg_maxseg < count)
796 		if (sg->sg_nseg != 0)
800 	/* Copy 'count' entries to 'sg' from 'original'. */
801 	bcopy(original->sg_segs, sg->sg_segs, count *
803 	sg->sg_nseg = count;
807 	 * 'sg' and the new first entry in 'original'.  We also
813 		sg->sg_segs[count].ss_len -= split;
815 		    sg->sg_segs[count].ss_paddr + split;
888 	struct sglist *sg;
938 		sg = sglist_alloc(count, mflags);
939 		if (sg == NULL)
941 		*slice = sg;
943 		sg = *slice;
944 		if (sg->sg_maxseg < count)
946 		if (sg->sg_nseg != 0)
952 	 * 'fseg' to 'sg'.
954 	bcopy(original->sg_segs + fseg, sg->sg_segs,
956 	sg->sg_nseg = count;
960 		sg->sg_segs[0].ss_paddr += foffs;
961 		sg->sg_segs[0].ss_len -= foffs;
963 		    (long)sg->sg_segs[0].ss_paddr, sg->sg_segs[0].ss_len);
966 		sg->sg_segs[count - 1].ss_len -= loffs;
968 		    sg->sg_segs[count - 1].ss_len);