vioblk/virtio: Re-arrange some struct members

This reduces holes/padding and makes the structs smaller.

diff --git a/sys/dev/pv/vioblk.c b/sys/dev/pv/vioblk.c
index 64552e3..cf8a033 100644 (file)
--- a/sys/dev/pv/vioblk.c
+++ b/sys/dev/pv/vioblk.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: vioblk.c,v 1.7 2017/05/30 19:28:09 sf Exp $   */
+/*     $OpenBSD: vioblk.c,v 1.8 2017/06/03 08:50:38 sf Exp $   */
 
 /*
  * Copyright (c) 2012 Stefan Fritsch.
@@ -87,12 +87,13 @@ struct virtio_feature_name vioblk_feature_names[] = {
 struct virtio_blk_req {
        struct virtio_blk_req_hdr        vr_hdr;
        uint8_t                          vr_status;
-       struct scsi_xfer                *vr_xs;
+#define VR_DMA_END     offsetof(struct virtio_blk_req, vr_qe_index)
+       int16_t                          vr_qe_index;
        int                              vr_len;
+       struct scsi_xfer                *vr_xs;
        bus_dmamap_t                     vr_cmdsts;
        bus_dmamap_t                     vr_payload;
        SLIST_ENTRY(virtio_blk_req)      vr_list;
-       int                              vr_qe_index;
 };
 
 struct vioblk_softc {
@@ -710,8 +711,7 @@ vioblk_alloc_reqs(struct vioblk_softc *sc, int qsize)
                vr->vr_len = VIOBLK_DONE;
 
                r = bus_dmamap_create(sc->sc_virtio->sc_dmat,
-                   offsetof(struct virtio_blk_req, vr_xs), 1,
-                   offsetof(struct virtio_blk_req, vr_xs), 0,
+                   VR_DMA_END, 1, VR_DMA_END, 0,
                    BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW, &vr->vr_cmdsts);
                if (r != 0) {
                        printf("cmd dmamap creation failed, err %d\n", r);
@@ -719,8 +719,7 @@ vioblk_alloc_reqs(struct vioblk_softc *sc, int qsize)
                        goto err_reqs;
                }
                r = bus_dmamap_load(sc->sc_virtio->sc_dmat, vr->vr_cmdsts,
-                   &vr->vr_hdr, offsetof(struct virtio_blk_req, vr_xs), NULL,
-                   BUS_DMA_NOWAIT);
+                   &vr->vr_hdr, VR_DMA_END, NULL, BUS_DMA_NOWAIT);
                if (r != 0) {
                        printf("command dmamap load failed, err %d\n", r);
                        nreqs = i;

diff --git a/sys/dev/pv/virtiovar.h b/sys/dev/pv/virtiovar.h
index 7b8a2f0..4b1f71c 100644 (file)
--- a/sys/dev/pv/virtiovar.h
+++ b/sys/dev/pv/virtiovar.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: virtiovar.h,v 1.5 2017/05/30 12:47:47 krw Exp $       */
+/*     $OpenBSD: virtiovar.h,v 1.6 2017/06/03 08:50:38 sf Exp $        */
 /*     $NetBSD: virtiovar.h,v 1.1 2011/10/30 12:12:21 hannken Exp $    */
 
 /*
@@ -86,9 +86,9 @@ struct vq_entry {
 
        /* The following are used only in the `head' entry */
        int16_t                  qe_next;       /* next enq slot */
-       struct vring_desc       *qe_desc_base;  /* pointer to vd array */
        int16_t                  qe_indirect;   /* 1 if using indirect */
        int16_t                  qe_vr_index;   /* index in sc_reqs array */
+       struct vring_desc       *qe_desc_base;  /* pointer to vd array */
 };
 
 struct virtqueue {