516 lines
14 KiB
C
516 lines
14 KiB
C
/* $NetBSD: viomb.c,v 1.1 2011/10/30 12:12:21 hannken Exp $ */
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/*
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* Copyright (c) 2010 Minoura Makoto.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: viomb.c,v 1.1 2011/10/30 12:12:21 hannken Exp $");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/bus.h>
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#include <sys/condvar.h>
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#include <sys/device.h>
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#include <sys/kthread.h>
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#include <sys/mutex.h>
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#include <sys/sysctl.h>
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#include <uvm/uvm_page.h>
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#include <dev/pci/pcidevs.h>
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#include <dev/pci/pcireg.h>
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#include <dev/pci/pcivar.h>
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#include <dev/pci/virtioreg.h>
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#include <dev/pci/virtiovar.h>
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/* Configuration registers */
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#define VIRTIO_BALLOON_CONFIG_NUM_PAGES 0 /* 32bit */
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#define VIRTIO_BALLOON_CONFIG_ACTUAL 4 /* 32bit */
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/* Feature bits */
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#define VIRTIO_BALLOON_F_MUST_TELL_HOST (1<<0)
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#define VIRTIO_BALLOON_F_STATS_VQ (1<<1)
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#define PGS_PER_REQ (256) /* 1MB, 4KB/page */
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CTASSERT((PAGE_SIZE) == (VIRTIO_PAGE_SIZE)); /* XXX */
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struct balloon_req {
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bus_dmamap_t bl_dmamap;
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struct pglist bl_pglist;
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int bl_nentries;
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uint32_t bl_pages[PGS_PER_REQ];
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};
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struct viomb_softc {
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device_t sc_dev;
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struct virtio_softc *sc_virtio;
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struct virtqueue sc_vq[2];
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unsigned int sc_npages;
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unsigned int sc_actual;
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int sc_inflight;
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struct balloon_req sc_req;
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struct pglist sc_balloon_pages;
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int sc_inflate_done;
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int sc_deflate_done;
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kcondvar_t sc_wait;
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kmutex_t sc_waitlock;
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};
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static int balloon_initialized = 0; /* multiple balloon is not allowed */
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static int viomb_match(device_t, cfdata_t, void *);
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static void viomb_attach(device_t, device_t, void *);
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static void viomb_read_config(struct viomb_softc *);
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static int viomb_config_change(struct virtio_softc *);
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static int inflate(struct viomb_softc *);
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static int inflateq_done(struct virtqueue *);
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static int inflate_done(struct viomb_softc *);
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static int deflate(struct viomb_softc *);
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static int deflateq_done(struct virtqueue *);
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static int deflate_done(struct viomb_softc *);
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static void viomb_thread(void *);
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CFATTACH_DECL_NEW(viomb, sizeof(struct viomb_softc),
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viomb_match, viomb_attach, NULL, NULL);
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static int
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viomb_match(device_t parent, cfdata_t match, void *aux)
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{
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struct virtio_softc *vsc = aux;
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if (vsc->sc_childdevid == PCI_PRODUCT_VIRTIO_BALLOON)
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return 1;
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return 0;
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}
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static void
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viomb_attach(device_t parent, device_t self, void *aux)
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{
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struct viomb_softc *sc = device_private(self);
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struct virtio_softc *vsc = device_private(parent);
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const struct sysctlnode *node;
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if (vsc->sc_child != NULL) {
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aprint_normal(": child already attached for %s; "
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"something wrong...\n",
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device_xname(parent));
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return;
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}
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if (balloon_initialized++) {
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aprint_normal(": balloon already exists; something wrong...\n");
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goto err_none;
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}
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aprint_normal("\n");
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sc->sc_dev = self;
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sc->sc_virtio = vsc;
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vsc->sc_child = self;
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vsc->sc_ipl = IPL_VM;
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vsc->sc_vqs = &sc->sc_vq[0];
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vsc->sc_nvqs = 2;
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vsc->sc_config_change = viomb_config_change;
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vsc->sc_intrhand = virtio_vq_intr;
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virtio_negotiate_features(vsc,
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VIRTIO_CONFIG_DEVICE_FEATURES);
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if ((virtio_alloc_vq(vsc, &sc->sc_vq[0], 0,
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sizeof(uint32_t)*PGS_PER_REQ, 1,
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"inflate") != 0) ||
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(virtio_alloc_vq(vsc, &sc->sc_vq[1], 1,
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sizeof(uint32_t)*PGS_PER_REQ, 1,
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"deflate") != 0)) {
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goto err_none;
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}
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sc->sc_vq[0].vq_done = inflateq_done;
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sc->sc_vq[1].vq_done = deflateq_done;
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viomb_read_config(sc);
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sc->sc_inflight = 0;
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TAILQ_INIT(&sc->sc_balloon_pages);
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if (bus_dmamap_create(vsc->sc_dmat, sizeof(uint32_t)*PGS_PER_REQ,
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1, sizeof(uint32_t)*PGS_PER_REQ, 0,
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BUS_DMA_NOWAIT, &sc->sc_req.bl_dmamap)) {
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aprint_error_dev(sc->sc_dev, "dmamap creation failed.\n");
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goto err_vq;
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}
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if (bus_dmamap_load(vsc->sc_dmat, sc->sc_req.bl_dmamap,
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&sc->sc_req.bl_pages[0],
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sizeof(uint32_t) * PGS_PER_REQ,
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NULL, BUS_DMA_NOWAIT)) {
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aprint_error_dev(sc->sc_dev, "dmamap load failed.\n");
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goto err_dmamap;
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}
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sc->sc_inflate_done = sc->sc_deflate_done = 0;
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mutex_init(&sc->sc_waitlock, MUTEX_DEFAULT, IPL_VM); /* spin */
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cv_init(&sc->sc_wait, "balloon");
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if (kthread_create(PRI_IDLE, KTHREAD_MPSAFE, NULL,
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viomb_thread, sc, NULL, "viomb")) {
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aprint_error_dev(sc->sc_dev, "cannot create kthread.\n");
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goto err_mutex;
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}
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sysctl_createv(NULL, 0, NULL, &node, 0, CTLTYPE_NODE,
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"viomb", SYSCTL_DESCR("VirtIO Balloon status"),
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NULL, 0, NULL, 0,
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CTL_HW, CTL_CREATE, CTL_EOL);
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sysctl_createv(NULL, 0, NULL, NULL, 0, CTLTYPE_INT,
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"npages", SYSCTL_DESCR("VirtIO Balloon npages value"),
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NULL, 0, &sc->sc_npages, 0,
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CTL_HW, node->sysctl_num, CTL_CREATE, CTL_EOL);
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sysctl_createv(NULL, 0, NULL, NULL, 0, CTLTYPE_INT,
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"actual", SYSCTL_DESCR("VirtIO Balloon actual value"),
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NULL, 0, &sc->sc_actual, 0,
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CTL_HW, node->sysctl_num, CTL_CREATE, CTL_EOL);
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return;
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err_mutex:
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cv_destroy(&sc->sc_wait);
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mutex_destroy(&sc->sc_waitlock);
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err_dmamap:
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bus_dmamap_destroy(vsc->sc_dmat, sc->sc_req.bl_dmamap);
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err_vq:
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virtio_free_vq(vsc, &sc->sc_vq[1]);
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virtio_free_vq(vsc, &sc->sc_vq[0]);
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err_none:
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vsc->sc_child = (void*)1;
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return;
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}
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static void
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viomb_read_config(struct viomb_softc *sc)
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{
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unsigned int reg;
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/* these values are explicitly specified as little-endian */
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reg = virtio_read_device_config_4(sc->sc_virtio,
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VIRTIO_BALLOON_CONFIG_NUM_PAGES);
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sc->sc_npages = le32toh(reg);
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reg = virtio_read_device_config_4(sc->sc_virtio,
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VIRTIO_BALLOON_CONFIG_ACTUAL);
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sc->sc_actual = le32toh(reg);
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}
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/*
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* Config change callback: wakeup the kthread.
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*/
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static int
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viomb_config_change(struct virtio_softc *vsc)
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{
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struct viomb_softc *sc = device_private(vsc->sc_child);
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unsigned int old;
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old = sc->sc_npages;
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viomb_read_config(sc);
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mutex_enter(&sc->sc_waitlock);
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cv_signal(&sc->sc_wait);
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mutex_exit(&sc->sc_waitlock);
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if (sc->sc_npages > old)
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printf("%s: inflating balloon from %u to %u.\n",
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device_xname(sc->sc_dev), old, sc->sc_npages);
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else if (sc->sc_npages < old)
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printf("%s: deflating balloon from %u to %u.\n",
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device_xname(sc->sc_dev), old, sc->sc_npages);
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return 1;
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}
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/*
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* Inflate: consume some amount of physical memory.
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*/
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static int
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inflate(struct viomb_softc *sc)
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{
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struct virtio_softc *vsc = sc->sc_virtio;
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int i, slot;
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uint64_t nvpages, nhpages;
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struct balloon_req *b;
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struct vm_page *p;
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struct virtqueue *vq = &sc->sc_vq[0];
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if (sc->sc_inflight)
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return 0;
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nvpages = sc->sc_npages - sc->sc_actual;
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if (nvpages > PGS_PER_REQ)
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nvpages = PGS_PER_REQ;
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nhpages = nvpages * VIRTIO_PAGE_SIZE / PAGE_SIZE;
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b = &sc->sc_req;
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if (uvm_pglistalloc(nhpages*PAGE_SIZE, 0, UINT32_MAX*PAGE_SIZE,
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0, 0, &b->bl_pglist, nhpages, 1)) {
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printf("%s: %" PRIu64 " pages of physical memory "
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"could not be allocated, retrying...\n",
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device_xname(sc->sc_dev), nhpages);
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return 1; /* sleep longer */
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}
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b->bl_nentries = nvpages;
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i = 0;
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TAILQ_FOREACH(p, &b->bl_pglist, pageq.queue) {
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b->bl_pages[i++] = p->phys_addr / VIRTIO_PAGE_SIZE;
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}
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KASSERT(i == nvpages);
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if (virtio_enqueue_prep(vsc, vq, &slot) != 0) {
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printf("%s: inflate enqueue failed.\n",
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device_xname(sc->sc_dev));
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uvm_pglistfree(&b->bl_pglist);
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return 0;
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}
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if (virtio_enqueue_reserve(vsc, vq, slot, 1)) {
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printf("%s: inflate enqueue failed.\n",
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device_xname(sc->sc_dev));
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uvm_pglistfree(&b->bl_pglist);
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return 0;
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}
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bus_dmamap_sync(vsc->sc_dmat, b->bl_dmamap, 0, sizeof(uint32_t)*nvpages,
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BUS_DMASYNC_PREWRITE);
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virtio_enqueue(vsc, vq, slot, b->bl_dmamap, true);
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virtio_enqueue_commit(vsc, vq, slot, true);
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sc->sc_inflight += nvpages;
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return 0;
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}
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static int
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inflateq_done(struct virtqueue *vq)
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{
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struct virtio_softc *vsc = vq->vq_owner;
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struct viomb_softc *sc = device_private(vsc->sc_child);
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mutex_enter(&sc->sc_waitlock);
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sc->sc_inflate_done = 1;
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cv_signal(&sc->sc_wait);
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mutex_exit(&sc->sc_waitlock);
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return 1;
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}
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static int
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inflate_done(struct viomb_softc *sc)
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{
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struct virtio_softc *vsc = sc->sc_virtio;
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struct virtqueue *vq = &sc->sc_vq[0];
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struct balloon_req *b;
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int r, slot;
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uint64_t nvpages;
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struct vm_page *p;
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r = virtio_dequeue(vsc, vq, &slot, NULL);
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if (r != 0) {
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printf("%s: inflate dequeue failed, errno %d.\n",
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device_xname(sc->sc_dev), r);
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return 1;
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}
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virtio_dequeue_commit(vsc, vq, slot);
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b = &sc->sc_req;
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nvpages = b->bl_nentries;
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bus_dmamap_sync(vsc->sc_dmat, b->bl_dmamap,
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offsetof(struct balloon_req, bl_pages),
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sizeof(uint32_t)*nvpages,
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BUS_DMASYNC_POSTWRITE);
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while (!TAILQ_EMPTY(&b->bl_pglist)) {
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p = TAILQ_FIRST(&b->bl_pglist);
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TAILQ_REMOVE(&b->bl_pglist, p, pageq.queue);
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TAILQ_INSERT_TAIL(&sc->sc_balloon_pages, p, pageq.queue);
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}
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sc->sc_inflight -= nvpages;
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virtio_write_device_config_4(vsc,
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VIRTIO_BALLOON_CONFIG_ACTUAL,
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sc->sc_actual + nvpages);
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viomb_read_config(sc);
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return 1;
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}
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/*
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* Deflate: free previously allocated memory.
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*/
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static int
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deflate(struct viomb_softc *sc)
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{
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struct virtio_softc *vsc = sc->sc_virtio;
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int i, slot;
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uint64_t nvpages, nhpages;
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struct balloon_req *b;
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struct vm_page *p;
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struct virtqueue *vq = &sc->sc_vq[1];
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nvpages = (sc->sc_actual + sc->sc_inflight) - sc->sc_npages;
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if (nvpages > PGS_PER_REQ)
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nvpages = PGS_PER_REQ;
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nhpages = nvpages * VIRTIO_PAGE_SIZE / PAGE_SIZE;
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b = &sc->sc_req;
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b->bl_nentries = nvpages;
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TAILQ_INIT(&b->bl_pglist);
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for (i = 0; i < nhpages; i++) {
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p = TAILQ_FIRST(&sc->sc_balloon_pages);
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TAILQ_REMOVE(&sc->sc_balloon_pages, p, pageq.queue);
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TAILQ_INSERT_TAIL(&b->bl_pglist, p, pageq.queue);
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b->bl_pages[i] = p->phys_addr / VIRTIO_PAGE_SIZE;
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}
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if (virtio_enqueue_prep(vsc, vq, &slot) != 0) {
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printf("%s: deflate enqueue failed.\n",
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device_xname(sc->sc_dev));
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TAILQ_FOREACH_REVERSE(p, &b->bl_pglist, pglist, pageq.queue) {
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TAILQ_REMOVE(&b->bl_pglist, p, pageq.queue);
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TAILQ_INSERT_HEAD(&sc->sc_balloon_pages, p, pageq.queue);
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}
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return 0;
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}
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if (virtio_enqueue_reserve(vsc, vq, slot, 1) != 0) {
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printf("%s: deflate enqueue failed.\n",
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device_xname(sc->sc_dev));
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TAILQ_FOREACH_REVERSE(p, &b->bl_pglist, pglist, pageq.queue) {
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TAILQ_REMOVE(&b->bl_pglist, p, pageq.queue);
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TAILQ_INSERT_HEAD(&sc->sc_balloon_pages, p, pageq.queue);
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}
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return 0;
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}
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bus_dmamap_sync(vsc->sc_dmat, b->bl_dmamap, 0, sizeof(uint32_t)*nvpages,
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BUS_DMASYNC_PREWRITE);
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virtio_enqueue(vsc, vq, slot, b->bl_dmamap, true);
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virtio_enqueue_commit(vsc, vq, slot, true);
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sc->sc_inflight -= nvpages;
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if (!(vsc->sc_features & VIRTIO_BALLOON_F_MUST_TELL_HOST))
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uvm_pglistfree(&b->bl_pglist);
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return 0;
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}
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static int
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deflateq_done(struct virtqueue *vq)
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{
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struct virtio_softc *vsc = vq->vq_owner;
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struct viomb_softc *sc = device_private(vsc->sc_child);
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mutex_enter(&sc->sc_waitlock);
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sc->sc_deflate_done = 1;
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cv_signal(&sc->sc_wait);
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mutex_exit(&sc->sc_waitlock);
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return 1;
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}
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static int
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deflate_done(struct viomb_softc *sc)
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{
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struct virtio_softc *vsc = sc->sc_virtio;
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struct virtqueue *vq = &sc->sc_vq[1];
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struct balloon_req *b;
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int r, slot;
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uint64_t nvpages, nhpages;
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r = virtio_dequeue(vsc, vq, &slot, NULL);
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if (r != 0) {
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printf("%s: deflate dequeue failed, errno %d\n",
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device_xname(sc->sc_dev), r);
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return 1;
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}
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virtio_dequeue_commit(vsc, vq, slot);
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b = &sc->sc_req;
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nvpages = b->bl_nentries;
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nhpages = nvpages * VIRTIO_PAGE_SIZE / PAGE_SIZE;
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bus_dmamap_sync(vsc->sc_dmat, b->bl_dmamap,
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offsetof(struct balloon_req, bl_pages),
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sizeof(uint32_t)*nvpages,
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BUS_DMASYNC_POSTWRITE);
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if (vsc->sc_features & VIRTIO_BALLOON_F_MUST_TELL_HOST)
|
|
uvm_pglistfree(&b->bl_pglist);
|
|
|
|
sc->sc_inflight += nvpages;
|
|
virtio_write_device_config_4(vsc,
|
|
VIRTIO_BALLOON_CONFIG_ACTUAL,
|
|
sc->sc_actual - nvpages);
|
|
viomb_read_config(sc);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Kthread: sleeps, eventually inflate and deflate.
|
|
*/
|
|
static void
|
|
viomb_thread(void *arg)
|
|
{
|
|
struct viomb_softc *sc = arg;
|
|
int sleeptime, r;
|
|
|
|
for ( ; ; ) {
|
|
sleeptime = 30000;
|
|
if (sc->sc_npages > sc->sc_actual + sc->sc_inflight) {
|
|
if (sc->sc_inflight == 0) {
|
|
r = inflate(sc);
|
|
if (r != 0)
|
|
sleeptime = 10000;
|
|
else
|
|
sleeptime = 1000;
|
|
} else
|
|
sleeptime = 100;
|
|
} else if (sc->sc_npages < sc->sc_actual + sc->sc_inflight) {
|
|
if (sc->sc_inflight == 0)
|
|
r = deflate(sc);
|
|
sleeptime = 100;
|
|
}
|
|
|
|
again:
|
|
mutex_enter(&sc->sc_waitlock);
|
|
if (sc->sc_inflate_done) {
|
|
sc->sc_inflate_done = 0;
|
|
mutex_exit(&sc->sc_waitlock);
|
|
inflate_done(sc);
|
|
goto again;
|
|
}
|
|
if (sc->sc_deflate_done) {
|
|
sc->sc_deflate_done = 0;
|
|
mutex_exit(&sc->sc_waitlock);
|
|
deflate_done(sc);
|
|
goto again;
|
|
}
|
|
cv_timedwait(&sc->sc_wait, &sc->sc_waitlock,
|
|
mstohz(sleeptime));
|
|
mutex_exit(&sc->sc_waitlock);
|
|
}
|
|
}
|