Re: [PATCH v4 13/17] remoteproc: create vdev subdevice with specific dma memory pool

[Wendy Liang]

On Fri, Jul 27, 2018 at 6:16 AM Loic Pallardy <loic.pallardy@xxxxxx> wrote:
>
> This patch creates a dedicated vdev subdevice for each vdev declared
> in firmware resource table and associates carveout named "vdev%dbuffer"
> (with %d vdev index in resource table) if any as dma coherent memory pool.
>
> Then vdev subdevice is used as parent for virtio device.
>
> Signed-off-by: Loic Pallardy <loic.pallardy@xxxxxx>
> ---
>  drivers/remoteproc/remoteproc_core.c     | 35 +++++++++++++++++++++++---
>  drivers/remoteproc/remoteproc_internal.h |  1 +
>  drivers/remoteproc/remoteproc_virtio.c   | 42 +++++++++++++++++++++++++++++++-
>  include/linux/remoteproc.h               |  1 +
>  4 files changed, 75 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 4edc6f0..adcc66e 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -39,6 +39,7 @@
>  #include <linux/idr.h>
>  #include <linux/elf.h>
>  #include <linux/crc32.h>
> +#include <linux/of_reserved_mem.h>
>  #include <linux/virtio_ids.h>
>  #include <linux/virtio_ring.h>
>  #include <asm/byteorder.h>
> @@ -145,7 +146,7 @@ static void rproc_disable_iommu(struct rproc *rproc)
>         iommu_domain_free(domain);
>  }
>
> -static phys_addr_t rproc_va_to_pa(void *cpu_addr)
> +phys_addr_t rproc_va_to_pa(void *cpu_addr)
>  {
>         /*
>          * Return physical address according to virtual address location
> @@ -160,6 +161,7 @@ static phys_addr_t rproc_va_to_pa(void *cpu_addr)
>         WARN_ON(!virt_addr_valid(cpu_addr));
>         return virt_to_phys(cpu_addr);
>  }
> +EXPORT_SYMBOL(rproc_va_to_pa);
>
>  /**
>   * rproc_da_to_va() - lookup the kernel virtual address for a remoteproc address
> @@ -423,6 +425,20 @@ static void rproc_vdev_do_stop(struct rproc_subdev *subdev, bool crashed)
>  }
>
>  /**
> + * rproc_rvdev_release() - release the existence of a rvdev
> + *
> + * @dev: the subdevice's dev
> + */
> +static void rproc_rvdev_release(struct device *dev)
> +{
> +       struct rproc_vdev *rvdev = container_of(dev, struct rproc_vdev, dev);
> +
> +       of_reserved_mem_device_release(dev);
> +
> +       kfree(rvdev);
> +}
> +
> +/**
>   * rproc_handle_vdev() - handle a vdev fw resource
>   * @rproc: the remote processor
>   * @rsc: the vring resource descriptor
> @@ -455,6 +471,7 @@ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
>         struct device *dev = &rproc->dev;
>         struct rproc_vdev *rvdev;
>         int i, ret;
> +       char name[16];
>
>         /* make sure resource isn't truncated */
>         if (sizeof(*rsc) + rsc->num_of_vrings * sizeof(struct fw_rsc_vdev_vring)
> @@ -488,6 +505,18 @@ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
>         rvdev->rproc = rproc;
>         rvdev->index = rproc->nb_vdev++;
>
> +       /* Initialise vdev subdevice */
> +       snprintf(name, sizeof(name), "vdev%dbuffer", rvdev->index);
> +       rvdev->dev.parent = rproc->dev.parent;
> +       rvdev->dev.release = rproc_rvdev_release;
> +       dev_set_name(&rvdev->dev, "%s#%s", dev_name(rvdev->dev.parent), name);
> +       dev_set_drvdata(&rvdev->dev, rvdev);
> +       dma_set_coherent_mask(&rvdev->dev, DMA_BIT_MASK(32));
I tried the latest kernel, this function will not set the DMA coherent mask as
dma_supported() of the &rvdev->dev will return false.
As this is a device created at run time, should it be force to support DMA?
should it directly set the dma_coherent_mask?

> +
> +       ret = device_register(&rvdev->dev);
> +       if (ret)
> +               goto free_rvdev;
> +
>         /* parse the vrings */
>         for (i = 0; i < rsc->num_of_vrings; i++) {
>                 ret = rproc_parse_vring(rvdev, rsc, i);
> @@ -518,7 +547,7 @@ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
>         for (i--; i >= 0; i--)
>                 rproc_free_vring(&rvdev->vring[i]);
>  free_rvdev:
> -       kfree(rvdev);
> +       device_unregister(&rvdev->dev);
>         return ret;
>  }
>
> @@ -536,7 +565,7 @@ void rproc_vdev_release(struct kref *ref)
>
>         rproc_remove_subdev(rproc, &rvdev->subdev);
>         list_del(&rvdev->node);
> -       kfree(rvdev);
> +       device_unregister(&rvdev->dev);
>  }
>
>  /**
> diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
> index f6cad24..bfeacfd 100644
> --- a/drivers/remoteproc/remoteproc_internal.h
> +++ b/drivers/remoteproc/remoteproc_internal.h
> @@ -52,6 +52,7 @@ struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
>  int rproc_alloc_vring(struct rproc_vdev *rvdev, int i);
>
>  void *rproc_da_to_va(struct rproc *rproc, u64 da, int len);
> +phys_addr_t rproc_va_to_pa(void *cpu_addr);
>  int rproc_trigger_recovery(struct rproc *rproc);
>
>  int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw);
> diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
> index de21f62..9ee63c0 100644
> --- a/drivers/remoteproc/remoteproc_virtio.c
> +++ b/drivers/remoteproc/remoteproc_virtio.c
> @@ -17,7 +17,9 @@
>   * GNU General Public License for more details.
>   */
>
> +#include <linux/dma-mapping.h>
>  #include <linux/export.h>
> +#include <linux/of_reserved_mem.h>
>  #include <linux/remoteproc.h>
>  #include <linux/virtio.h>
>  #include <linux/virtio_config.h>
> @@ -315,10 +317,48 @@ static void rproc_virtio_dev_release(struct device *dev)
>  int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
>  {
>         struct rproc *rproc = rvdev->rproc;
> -       struct device *dev = &rproc->dev;
> +       struct device *dev = &rvdev->dev;
>         struct virtio_device *vdev = &rvdev->vdev;
> +       struct rproc_mem_entry *mem;
>         int ret;
>
> +       /* Try to find dedicated vdev buffer carveout */
> +       mem = rproc_find_carveout_by_name(rproc, "vdev%dbuffer", rvdev->index);
> +       if (mem) {
> +               phys_addr_t pa;
> +
> +               if (mem->of_resm_idx != -1) {
> +                       struct device_node *np = rproc->dev.parent->of_node;
> +
> +                       /* Associate reserved memory to vdev device */
> +                       ret = of_reserved_mem_device_init_by_idx(dev, np,
> +                                                                mem->of_resm_idx);
> +                       if (ret) {
> +                               dev_err(dev, "Can't associate reserved memory\n");
> +                               goto out;
> +                       }
> +               } else {
> +                       if (mem->va) {
> +                               dev_warn(dev, "vdev %d buffer already mapped\n",
> +                                        rvdev->index);
> +                               pa = rproc_va_to_pa(mem->va);
> +                       } else {
> +                               /* Use dma address as carveout no memmapped yet */
> +                               pa = (phys_addr_t)mem->dma;
> +                       }
> +
> +                       /* Associate vdev buffer memory pool to vdev subdev */
> +                       ret = dmam_declare_coherent_memory(dev, pa,
> +                                                          mem->da,
> +                                                          mem->len,
> +                                                          DMA_MEMORY_EXCLUSIVE);
> +                       if (ret < 0) {
> +                               dev_err(dev, "Failed to associate buffer\n");
> +                               goto out;
> +                       }
> +               }
> +       }
> +
>         vdev->id.device = id,
>         vdev->config = &rproc_virtio_config_ops,
>         vdev->dev.parent = dev;
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index 6b3a234..2921dd2 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -547,6 +547,7 @@ struct rproc_vdev {
>         struct kref refcount;
>
>         struct rproc_subdev subdev;
> +       struct device dev;
>
>         unsigned int id;
>         struct list_head node;
> --
> 1.9.1
>
> --
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