Author: cperciva
Date: Sat Jun 20 00:02:03 2015
New Revision: 284618
URL: https://svnweb.freebsd.org/changeset/base/284618
Log:
Refactor xbd_queue_cb, extracting the code which converts bus_dma segments
into blkif segments, and moving it into a new function. This will be used
by upcoming support for indirect-segment blkif requests.
This commit should not result in any functional changes.
Modified:
head/sys/dev/xen/blkfront/blkfront.c
Modified: head/sys/dev/xen/blkfront/blkfront.c
==============================================================================
--- head/sys/dev/xen/blkfront/blkfront.c Fri Jun 19 23:03:05 2015
(r284617)
+++ head/sys/dev/xen/blkfront/blkfront.c Sat Jun 20 00:02:03 2015
(r284618)
@@ -156,45 +156,14 @@ xbd_free_command(struct xbd_command *cm)
}
static void
-xbd_queue_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
+mksegarray(bus_dma_segment_t *segs, int nsegs,
+ grant_ref_t * gref_head, int otherend_id, int readonly,
+ grant_ref_t * sg_ref, blkif_request_segment_t * sg)
{
- struct xbd_softc *sc;
- struct xbd_command *cm;
- blkif_request_t *ring_req;
- struct blkif_request_segment *sg;
- struct blkif_request_segment *last_block_sg;
- grant_ref_t *sg_ref;
+ struct blkif_request_segment *last_block_sg = sg + nsegs;
vm_paddr_t buffer_ma;
uint64_t fsect, lsect;
int ref;
- int op;
-
- cm = arg;
- sc = cm->cm_sc;
-
- if (error) {
- cm->cm_bp->bio_error = EIO;
- biodone(cm->cm_bp);
- xbd_free_command(cm);
- return;
- }
-
- KASSERT(nsegs <= BLKIF_MAX_SEGMENTS_PER_REQUEST,
- ("Too many segments in a blkfront I/O"));
-
- /* Fill out a communications ring structure. */
- ring_req = RING_GET_REQUEST(&sc->xbd_ring, sc->xbd_ring.req_prod_pvt);
- sc->xbd_ring.req_prod_pvt++;
- ring_req->id = cm->cm_id;
- ring_req->operation = cm->cm_operation;
- ring_req->sector_number = cm->cm_sector_number;
- ring_req->handle = (blkif_vdev_t)(uintptr_t)sc->xbd_disk;
- ring_req->nr_segments = nsegs;
- cm->cm_nseg = nsegs;
-
- sg = ring_req->seg;
- last_block_sg = sg + nsegs;
- sg_ref = cm->cm_sg_refs;
while (sg < last_block_sg) {
buffer_ma = segs->ds_addr;
@@ -205,7 +174,7 @@ xbd_queue_cb(void *arg, bus_dma_segment_
"cross a page boundary"));
/* install a grant reference. */
- ref = gnttab_claim_grant_reference(&cm->cm_gref_head);
+ ref = gnttab_claim_grant_reference(gref_head);
/*
* GNTTAB_LIST_END == 0xffffffff, but it is private
@@ -215,9 +184,9 @@ xbd_queue_cb(void *arg, bus_dma_segment_
gnttab_grant_foreign_access_ref(
ref,
- xenbus_get_otherend_id(sc->xbd_dev),
+ otherend_id,
buffer_ma >> PAGE_SHIFT,
- ring_req->operation == BLKIF_OP_WRITE);
+ readonly);
*sg_ref = ref;
*sg = (struct blkif_request_segment) {
@@ -229,6 +198,42 @@ xbd_queue_cb(void *arg, bus_dma_segment_
sg_ref++;
segs++;
}
+}
+
+static void
+xbd_queue_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
+{
+ struct xbd_softc *sc;
+ struct xbd_command *cm;
+ blkif_request_t *ring_req;
+ int op;
+
+ cm = arg;
+ sc = cm->cm_sc;
+
+ if (error) {
+ cm->cm_bp->bio_error = EIO;
+ biodone(cm->cm_bp);
+ xbd_free_command(cm);
+ return;
+ }
+
+ KASSERT(nsegs <= BLKIF_MAX_SEGMENTS_PER_REQUEST,
+ ("Too many segments in a blkfront I/O"));
+
+ /* Fill out a communications ring structure. */
+ ring_req = RING_GET_REQUEST(&sc->xbd_ring, sc->xbd_ring.req_prod_pvt);
+ sc->xbd_ring.req_prod_pvt++;
+ ring_req->id = cm->cm_id;
+ ring_req->operation = cm->cm_operation;
+ ring_req->sector_number = cm->cm_sector_number;
+ ring_req->handle = (blkif_vdev_t)(uintptr_t)sc->xbd_disk;
+ ring_req->nr_segments = nsegs;
+ cm->cm_nseg = nsegs;
+ mksegarray(segs, nsegs, &cm->cm_gref_head,
+ xenbus_get_otherend_id(sc->xbd_dev),
+ cm->cm_operation == BLKIF_OP_WRITE,
+ cm->cm_sg_refs, ring_req->seg);
if (cm->cm_operation == BLKIF_OP_READ)
op = BUS_DMASYNC_PREREAD;
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