viomb(4): replace workqs with tasks

[David Gwynne]

i dont have the "hardware" to test this on. could someone give it
a go and see if it still works?

cheers,
dlg

Index: viomb.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/viomb.c,v
retrieving revision 1.6
diff -u -p -r1.6 viomb.c
--- viomb.c     2 Jul 2013 15:46:14 -0000       1.6
+++ viomb.c     30 Oct 2013 02:29:39 -0000
@@ -30,7 +30,7 @@
 #include <sys/systm.h>
 #include <sys/malloc.h>
 #include <sys/device.h>
-#include <sys/workq.h>
+#include <sys/task.h>
 #include <sys/pool.h>
 #include <uvm/uvm.h>
 #include <dev/pci/pcidevs.h>
@@ -93,8 +93,8 @@ struct viomb_softc {
        u_int32_t               sc_npages;
        u_int32_t               sc_actual;
        struct balloon_req      sc_req;
-       struct workq_task       sc_task;
-       int                     sc_workq_queued;
+       struct taskq            *sc_taskq;
+       struct task             sc_task;
        struct pglist           sc_balloon_pages;
 };
 
@@ -117,8 +117,6 @@ struct cfdriver viomb_cd = {
        NULL, "viomb", DV_DULL
 };
 
-struct workq *viomb_workq;
-
 int
 viomb_match(struct device *parent, void *match, void *aux)
 {
@@ -198,9 +196,11 @@ viomb_attach(struct device *parent, stru
                goto err_dmamap;
        }
 
-       viomb_workq = workq_create("viomb", 1, IPL_BIO);
-       if (viomb_workq == NULL)
+       sc->sc_taskq = taskq_create("viomb", 1, IPL_BIO);
+       if (sc->sc_taskq == NULL)
                goto err_dmamap;
+       task_set(&sc->sc_task, viomb_worker, sc, NULL);
+
        printf("\n");
        return;
 err_dmamap:
@@ -223,11 +223,8 @@ viomb_config_change(struct virtio_softc 
 {
        struct viomb_softc *sc = (struct viomb_softc *)vsc->sc_child;
 
-       if (sc->sc_workq_queued == 0){
-               workq_queue_task(viomb_workq, &sc->sc_task, 0,
-                                viomb_worker, sc, NULL);
-               sc->sc_workq_queued = 1;
-       }
+       task_add(sc->sc_taskq, &sc->sc_task);
+
        return (1);
 }
 
@@ -238,7 +235,6 @@ viomb_worker(void *arg1, void *arg2)
        int s;
 
        s = splbio();
-       sc->sc_workq_queued = 0;
        viomb_read_config(sc);
        if (sc->sc_npages > sc->sc_actual){
                VIOMBDEBUG(sc, "inflating balloon from %u to %u.\n",
@@ -422,12 +418,11 @@ viomb_inflate_intr(struct virtqueue *vq)
        virtio_write_device_config_4(vsc, VIRTIO_BALLOON_CONFIG_ACTUAL,
                                     sc->sc_actual + nvpages);
        viomb_read_config(sc);
+
        /* if we have more work to do, add it to the task list */
-       if (sc->sc_npages > sc->sc_actual && sc->sc_workq_queued == 0){
-               workq_queue_task(viomb_workq, &sc->sc_task, 0,
-                                viomb_worker, sc, NULL);
-               sc->sc_workq_queued = 1;
-       }
+       if (sc->sc_npages > sc->sc_actual)
+               task_add(sc->sc_taskq, &sc->sc_task);
+
        return (1);
 }
 
@@ -458,10 +453,8 @@ viomb_deflate_intr(struct virtqueue *vq)
        viomb_read_config(sc);
 
        /* if we have more work to do, add it to tasks list */
-       if (sc->sc_npages < sc->sc_actual && sc->sc_workq_queued == 0){
-               workq_queue_task(viomb_workq, &sc->sc_task, 0,
-                                viomb_worker, sc, NULL);
-               sc->sc_workq_queued = 1;
-       }
+       if (sc->sc_npages < sc->sc_actual)
+               task_add(sc->sc_taskq, &sc->sc_task);
+
        return(1);
 }