[PATCH] remoteproc: allocate vrings on demand, free when not needed

Guzman Lugo, Fernando fernando.lugo at ti.com
Mon May 21 12:40:10 EDT 2012


Looks good to me.

 Tested-by: Fernando Guzman Lugo <fernando.lugo at ti.com>

Regards,
Fernando.

On Sun, May 20, 2012 at 7:00 AM, Ohad Ben-Cohen <ohad at wizery.com> wrote:

> Dynamically allocate the vrings' DMA when the remote processor
> is about to be powered on (i.e. when ->find_vqs() is invoked),
> and release them as soon as it is powered off (i.e. when ->del_vqs()
> is invoked).
>

The obvious and immediate benefit is better memory utilization, since
> memory for the vrings is now only allocated when the relevant remote
> processor is being used.
>
> Additionally, this approach also makes recovery of a (crashing)
> remote processor easier: one just needs to remove the relevant
> vdevs, and the entire vrings cleanup takes place automagically.
>
> Tested-by: Fernando Guzman Lugo <fernando.lugo at ti.com>
> Signed-off-by: Ohad Ben-Cohen <ohad at wizery.com>
> ---
>  drivers/remoteproc/remoteproc_core.c     |  109
> +++++++++++++++---------------
>  drivers/remoteproc/remoteproc_internal.h |    2 +
>  drivers/remoteproc/remoteproc_virtio.c   |   13 +++-
>  3 files changed, 67 insertions(+), 57 deletions(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c
> b/drivers/remoteproc/remoteproc_core.c
> index e756a0d..40e2b2d 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -279,34 +279,17 @@ rproc_load_segments(struct rproc *rproc, const u8
> *elf_data, size_t len)
>        return ret;
>  }
>
> -static int
> -__rproc_handle_vring(struct rproc_vdev *rvdev, struct fw_rsc_vdev *rsc,
> int i)
> +int rproc_alloc_vring(struct rproc_vdev *rvdev, int i)
>  {
>        struct rproc *rproc = rvdev->rproc;
>        struct device *dev = rproc->dev;
> -       struct fw_rsc_vdev_vring *vring = &rsc->vring[i];
> +       struct rproc_vring *rvring = &rvdev->vring[i];
>        dma_addr_t dma;
>        void *va;
>        int ret, size, notifyid;
>
> -       dev_dbg(dev, "vdev rsc: vring%d: da %x, qsz %d, align %d\n",
> -                               i, vring->da, vring->num, vring->align);
> -
> -       /* make sure reserved bytes are zeroes */
> -       if (vring->reserved) {
> -               dev_err(dev, "vring rsc has non zero reserved bytes\n");
> -               return -EINVAL;
> -       }
> -
> -       /* verify queue size and vring alignment are sane */
> -       if (!vring->num || !vring->align) {
> -               dev_err(dev, "invalid qsz (%d) or alignment (%d)\n",
> -                                               vring->num, vring->align);
> -               return -EINVAL;
> -       }
> -
>        /* actual size of vring (in bytes) */
> -       size = PAGE_ALIGN(vring_size(vring->num, vring->align));
> +       size = PAGE_ALIGN(vring_size(rvring->len, rvring->align));
>
>        if (!idr_pre_get(&rproc->notifyids, GFP_KERNEL)) {
>                dev_err(dev, "idr_pre_get failed\n");
> @@ -316,6 +299,7 @@ __rproc_handle_vring(struct rproc_vdev *rvdev, struct
> fw_rsc_vdev *rsc, int i)
>        /*
>         * Allocate non-cacheable memory for the vring. In the future
>         * this call will also configure the IOMMU for us
> +        * TODO: let the rproc know the da of this vring
>         */
>        va = dma_alloc_coherent(dev, size, &dma, GFP_KERNEL);
>        if (!va) {
> @@ -323,44 +307,67 @@ __rproc_handle_vring(struct rproc_vdev *rvdev,
> struct fw_rsc_vdev *rsc, int i)
>                return -EINVAL;
>        }
>
> -       /* assign an rproc-wide unique index for this vring */
> -       /* TODO: assign a notifyid for rvdev updates as well */
> -       ret = idr_get_new(&rproc->notifyids, &rvdev->vring[i], &notifyid);
> +       /*
> +        * Assign an rproc-wide unique index for this vring
> +        * TODO: assign a notifyid for rvdev updates as well
> +        * TODO: let the rproc know the notifyid of this vring
> +        * TODO: support predefined notifyids (via resource table)
> +        */
> +       ret = idr_get_new(&rproc->notifyids, rvring, &notifyid);
>        if (ret) {
>                dev_err(dev, "idr_get_new failed: %d\n", ret);
>                dma_free_coherent(dev, size, va, dma);
>                return ret;
>        }
>
> -       /* let the rproc know the da and notifyid of this vring */
> -       /* TODO: expose this to remote processor */
> -       vring->da = dma;
> -       vring->notifyid = notifyid;
> -
>        dev_dbg(dev, "vring%d: va %p dma %x size %x idr %d\n", i, va,
>                                        dma, size, notifyid);
>
> -       rvdev->vring[i].len = vring->num;
> -       rvdev->vring[i].align = vring->align;
> -       rvdev->vring[i].va = va;
> -       rvdev->vring[i].dma = dma;
> -       rvdev->vring[i].notifyid = notifyid;
> -       rvdev->vring[i].rvdev = rvdev;
> +       rvring->va = va;
> +       rvring->dma = dma;
> +       rvring->notifyid = notifyid;
>
>        return 0;
>  }
>
> -static void __rproc_free_vrings(struct rproc_vdev *rvdev, int i)
> +static int
> +rproc_parse_vring(struct rproc_vdev *rvdev, struct fw_rsc_vdev *rsc, int
> i)
>  {
>        struct rproc *rproc = rvdev->rproc;
> +       struct device *dev = rproc->dev;
> +       struct fw_rsc_vdev_vring *vring = &rsc->vring[i];
> +       struct rproc_vring *rvring = &rvdev->vring[i];
>
> -       for (i--; i >= 0; i--) {
> -               struct rproc_vring *rvring = &rvdev->vring[i];
> -               int size = PAGE_ALIGN(vring_size(rvring->len,
> rvring->align));
> +       dev_dbg(dev, "vdev rsc: vring%d: da %x, qsz %d, align %d\n",
> +                               i, vring->da, vring->num, vring->align);
> +
> +       /* make sure reserved bytes are zeroes */
> +       if (vring->reserved) {
> +               dev_err(dev, "vring rsc has non zero reserved bytes\n");
> +               return -EINVAL;
> +       }
>
> -               dma_free_coherent(rproc->dev, size, rvring->va,
> rvring->dma);
> -               idr_remove(&rproc->notifyids, rvring->notifyid);
> +       /* verify queue size and vring alignment are sane */
> +       if (!vring->num || !vring->align) {
> +               dev_err(dev, "invalid qsz (%d) or alignment (%d)\n",
> +                                               vring->num, vring->align);
> +               return -EINVAL;
>        }
> +
> +       rvring->len = vring->num;
> +       rvring->align = vring->align;
> +       rvring->rvdev = rvdev;
> +
> +       return 0;
> +}
> +
> +void rproc_free_vring(struct rproc_vring *rvring)
> +{
> +       int size = PAGE_ALIGN(vring_size(rvring->len, rvring->align));
> +       struct rproc *rproc = rvring->rvdev->rproc;
> +
> +       dma_free_coherent(rproc->dev, size, rvring->va, rvring->dma);
> +       idr_remove(&rproc->notifyids, rvring->notifyid);
>  }
>
>  /**
> @@ -425,11 +432,11 @@ static int rproc_handle_vdev(struct rproc *rproc,
> struct fw_rsc_vdev *rsc,
>
>        rvdev->rproc = rproc;
>
> -       /* allocate the vrings */
> +       /* parse the vrings */
>        for (i = 0; i < rsc->num_of_vrings; i++) {
> -               ret = __rproc_handle_vring(rvdev, rsc, i);
> +               ret = rproc_parse_vring(rvdev, rsc, i);
>                if (ret)
> -                       goto free_vrings;
> +                       goto free_rvdev;
>        }
>
>        /* remember the device features */
> @@ -440,12 +447,11 @@ static int rproc_handle_vdev(struct rproc *rproc,
> struct fw_rsc_vdev *rsc,
>        /* it is now safe to add the virtio device */
>        ret = rproc_add_virtio_dev(rvdev, rsc->id);
>        if (ret)
> -               goto free_vrings;
> +               goto free_rvdev;
>
>        return 0;
>
> -free_vrings:
> -       __rproc_free_vrings(rvdev, i);
> +free_rvdev:
>        kfree(rvdev);
>        return ret;
>  }
> @@ -1265,18 +1271,11 @@ EXPORT_SYMBOL(rproc_shutdown);
>  void rproc_release(struct kref *kref)
>  {
>        struct rproc *rproc = container_of(kref, struct rproc, refcount);
> -       struct rproc_vdev *rvdev, *rvtmp;
>
>        dev_info(rproc->dev, "removing %s\n", rproc->name);
>
>        rproc_delete_debug_dir(rproc);
>
> -       /* clean up remote vdev entries */
> -       list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node) {
> -               __rproc_free_vrings(rvdev, RVDEV_NUM_VRINGS);
> -               list_del(&rvdev->node);
> -       }
> -
>        /*
>         * At this point no one holds a reference to rproc anymore,
>         * so we can directly unroll rproc_alloc()
> @@ -1547,7 +1546,7 @@ EXPORT_SYMBOL(rproc_free);
>  */
>  int rproc_unregister(struct rproc *rproc)
>  {
> -       struct rproc_vdev *rvdev;
> +       struct rproc_vdev *rvdev, *tmp;
>
>        if (!rproc)
>                return -EINVAL;
> @@ -1556,7 +1555,7 @@ int rproc_unregister(struct rproc *rproc)
>        wait_for_completion(&rproc->firmware_loading_complete);
>
>        /* clean up remote vdev entries */
> -       list_for_each_entry(rvdev, &rproc->rvdevs, node)
> +       list_for_each_entry_safe(rvdev, tmp, &rproc->rvdevs, node)
>                rproc_remove_virtio_dev(rvdev);
>
>        /* the rproc is downref'ed as soon as it's removed from the klist */
> diff --git a/drivers/remoteproc/remoteproc_internal.h
> b/drivers/remoteproc/remoteproc_internal.h
> index 9f336d6..f4957cf 100644
> --- a/drivers/remoteproc/remoteproc_internal.h
> +++ b/drivers/remoteproc/remoteproc_internal.h
> @@ -41,4 +41,6 @@ void rproc_create_debug_dir(struct rproc *rproc);
>  void rproc_init_debugfs(void);
>  void rproc_exit_debugfs(void);
>
> +void rproc_free_vring(struct rproc_vring *rvring);
> +int rproc_alloc_vring(struct rproc_vdev *rvdev, int i);
>  #endif /* REMOTEPROC_INTERNAL_H */
> diff --git a/drivers/remoteproc/remoteproc_virtio.c
> b/drivers/remoteproc/remoteproc_virtio.c
> index ecf6121..26a7144 100644
> --- a/drivers/remoteproc/remoteproc_virtio.c
> +++ b/drivers/remoteproc/remoteproc_virtio.c
> @@ -77,14 +77,17 @@ static struct virtqueue *rp_find_vq(struct
> virtio_device *vdev,
>        struct rproc_vring *rvring;
>        struct virtqueue *vq;
>        void *addr;
> -       int len, size;
> +       int len, size, ret;
>
>        /* we're temporarily limited to two virtqueues per rvdev */
>        if (id >= ARRAY_SIZE(rvdev->vring))
>                return ERR_PTR(-EINVAL);
>
> -       rvring = &rvdev->vring[id];
> +       ret = rproc_alloc_vring(rvdev, id);
> +       if (ret)
> +               return ERR_PTR(ret);
>
> +       rvring = &rvdev->vring[id];
>        addr = rvring->va;
>        len = rvring->len;
>
> @@ -103,6 +106,7 @@ static struct virtqueue *rp_find_vq(struct
> virtio_device *vdev,
>                                        rproc_virtio_notify, callback,
> name);
>        if (!vq) {
>                dev_err(rproc->dev, "vring_new_virtqueue %s failed\n",
> name);
> +               rproc_free_vring(rvring);
>                return ERR_PTR(-ENOMEM);
>        }
>
> @@ -125,6 +129,7 @@ static void rproc_virtio_del_vqs(struct virtio_device
> *vdev)
>                rvring = vq->priv;
>                rvring->vq = NULL;
>                vring_del_virtqueue(vq);
> +               rproc_free_vring(rvring);
>        }
>  }
>
> @@ -228,8 +233,12 @@ static struct virtio_config_ops
> rproc_virtio_config_ops = {
>  static void rproc_vdev_release(struct device *dev)
>  {
>        struct virtio_device *vdev = dev_to_virtio(dev);
> +       struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
>        struct rproc *rproc = vdev_to_rproc(vdev);
>
> +       list_del(&rvdev->node);
> +       kfree(rvdev);
> +
>        kref_put(&rproc->refcount, rproc_release);
>  }
>
> --
> 1.7.5.4
>
> --
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