Re: [RFC PATCH 7/7] remoteproc: Instantiate the new remoteproc virtio platform device
From: Arnaud POULIQUEN
Date: Wed Nov 03 2021 - 05:16:48 EST
Hi Mathieu
On 10/22/21 7:58 PM, Mathieu Poirier wrote:
> On Fri, Oct 01, 2021 at 12:12:34PM +0200, Arnaud Pouliquen wrote:
>> Migrate from the rvdev device to the rvdev platform device.
>> From this patch, when a vdev resource is found in the resource table
>> the remoteproc core register a platform device.
>>
>> All reference to the rvdev->dev has been updated to rvdev-pdev->dev
>>
>> The use of kref counter is replaced by get/put_device on the remoteproc
>> virtio device.
>>
>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
>> ---
>> drivers/remoteproc/remoteproc_core.c | 49 +++++++------
>> drivers/remoteproc/remoteproc_internal.h | 16 ----
>> drivers/remoteproc/remoteproc_virtio.c | 93 ++++++------------------
>> include/linux/remoteproc.h | 4 -
>> 4 files changed, 50 insertions(+), 112 deletions(-)
>>
>> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
>> index 67ccd088db8f..d9256db8b130 100644
>> --- a/drivers/remoteproc/remoteproc_core.c
>> +++ b/drivers/remoteproc/remoteproc_core.c
>> @@ -467,6 +467,8 @@ static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
>> {
>> struct fw_rsc_vdev *rsc = ptr;
>> struct device *dev = &rproc->dev;
>> + struct rproc_vdev_data vdev_data;
>> + struct platform_device *pdev;
>> struct rproc_vdev *rvdev;
>> int i, ret;
>>
>> @@ -486,28 +488,34 @@ static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
>> dev_dbg(dev, "vdev rsc: id %d, dfeatures 0x%x, cfg len %d, %d vrings\n",
>> rsc->id, rsc->dfeatures, rsc->config_len, rsc->num_of_vrings);
>>
>> - /* we currently support only two vrings per rvdev */
>> - if (rsc->num_of_vrings > ARRAY_SIZE(rvdev->vring)) {
>> - dev_err(dev, "too many vrings: %d\n", rsc->num_of_vrings);
>> - return -EINVAL;
>> - }
>> + /* platform data of the new rvdev platform */
>> + vdev_data.rsc_offset = offset;
>> + vdev_data.id = rsc->id;
>> + vdev_data.index = rproc->nb_vdev;
>>
>> - rvdev = kzalloc(sizeof(*rvdev), GFP_KERNEL);
>> - if (!rvdev)
>> - return -ENOMEM;
>> -
>> - kref_init(&rvdev->refcount);
>> -
>> - rvdev->id = rsc->id;
>> - rvdev->rproc = rproc;
>> - rvdev->index = rproc->nb_vdev;
>> + pdev = rproc_virtio_register_device(rproc, &vdev_data);
>> + if (PTR_ERR_OR_ZERO(pdev)) {
>> + dev_err(rproc->dev.parent,
>> + "failed to create rproc-virtio device\n");
>> + return PTR_ERR_OR_ZERO(pdev);
>> + }
>>
>> - ret = rproc_rvdev_add_device(rvdev);
>> - if (ret)
>> - return ret;
>> + /* If we made it to this point the remote proc virtio platform at been probed */
>> + rvdev = platform_get_drvdata(pdev);
>> + if (WARN_ON(!rvdev)) {
>> + ret = -EINVAL;
>> + goto free_rvdev;
>> + }
>>
>> rproc->nb_vdev++;
>>
>> + /* we currently support only two vrings per rvdev */
>> + if (rsc->num_of_vrings > ARRAY_SIZE(rvdev->vring)) {
>> + dev_err(dev, "too many vrings: %d\n", rsc->num_of_vrings);
>> + ret = -EINVAL;
>> + goto free_rvdev;
>> + }
>> +
>> /* parse the vrings */
>> for (i = 0; i < rsc->num_of_vrings; i++) {
>> ret = rproc_parse_vring(rvdev, rsc, i);
>> @@ -515,9 +523,6 @@ static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
>> goto free_rvdev;
>> }
>>
>> - /* remember the resource offset*/
>> - rvdev->rsc_offset = offset;
>> -
>> /* allocate the vring resources */
>> for (i = 0; i < rsc->num_of_vrings; i++) {
>> ret = rproc_alloc_vring(rvdev, i);
>> @@ -531,7 +536,7 @@ static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
>> for (i--; i >= 0; i--)
>> rproc_free_vring(&rvdev->vring[i]);
>> free_rvdev:
>> - device_unregister(&rvdev->dev);
>> + rproc_virtio_unregister_device(rvdev);
>> return ret;
>> }
>
> I have made it up to here but running out of time for this patchset. I will review
> the rest in another revision. I haven't found a justification for
> rproc_register_rvdev() and rproc_unregister_rvdev(). Am I missing something or
> they can simply be removed and the list manipulations done in the code as it
> currently is?
>
You are right, it seems unnecessary. I need to double check why I introduced
these functions, but this needs at least a rational in the commit.
I will send a new revision taking into account your and Bjorn's remarks.
Thanks,
Arnaud
> Thanks,
> Mathieu
>
>>
>> @@ -1270,7 +1275,7 @@ void rproc_resource_cleanup(struct rproc *rproc)
>>
>> /* clean up remote vdev entries */
>> list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node)
>> - kref_put(&rvdev->refcount, rproc_vdev_release);
>> + rproc_virtio_unregister_device(rvdev);
>>
>> rproc_coredump_cleanup(rproc);
>> }
>> diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
>> index 0bb1b14e5136..2f68e7380c77 100644
>> --- a/drivers/remoteproc/remoteproc_internal.h
>> +++ b/drivers/remoteproc/remoteproc_internal.h
>> @@ -38,12 +38,10 @@ int rproc_of_parse_firmware(struct device *dev, int index,
>> /* from remoteproc_virtio.c */
>> #if IS_ENABLED(CONFIG_REMOTEPROC_VIRTIO)
>>
>> -int rproc_rvdev_add_device(struct rproc_vdev *rvdev);
>> struct platform_device *
>> rproc_virtio_register_device(struct rproc *rproc, struct rproc_vdev_data *vdev_data);
>> void rproc_virtio_unregister_device(struct rproc_vdev *rvdev);
>> irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id);
>> -void rproc_vdev_release(struct kref *ref);
>>
>> #else
>>
>> @@ -59,14 +57,6 @@ static inline void rproc_virtio_unregister_device(struct rproc_vdev *rvdev)
>> WARN_ON(1);
>> }
>>
>> -int rproc_rvdev_add_device(struct rproc_vdev *rvdev)
>> -{
>> - /* This shouldn't be possible */
>> - WARN_ON(1);
>> -
>> - return -ENXIO;
>> -}
>> -
>> static inline irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id)
>> {
>> /* This shouldn't be possible */
>> @@ -75,12 +65,6 @@ static inline irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id)
>> return IRQ_NONE;
>> }
>>
>> -static inline void rproc_vdev_release(struct kref *ref)
>> -{
>> - /* This shouldn't be possible */
>> - WARN_ON(1);
>> -}
>> -
>> #endif
>>
>> /* from remoteproc_debugfs.c */
>> diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
>> index 7188fb8ce40f..34781a2136e6 100644
>> --- a/drivers/remoteproc/remoteproc_virtio.c
>> +++ b/drivers/remoteproc/remoteproc_virtio.c
>> @@ -29,7 +29,11 @@
>>
>> static struct rproc_vdev *vdev_to_rvdev(struct virtio_device *vdev)
>> {
>> - return container_of(vdev->dev.parent, struct rproc_vdev, dev);
>> + struct platform_device *pdev;
>> +
>> + pdev = container_of(vdev->dev.parent, struct platform_device, dev);
>> +
>> + return platform_get_drvdata(pdev);
>> }
>>
>> static struct rproc *vdev_to_rproc(struct virtio_device *vdev)
>> @@ -343,13 +347,10 @@ static void rproc_virtio_dev_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);
>>
>> kfree(vdev);
>>
>> - kref_put(&rvdev->refcount, rproc_vdev_release);
>> -
>> - put_device(&rproc->dev);
>> + put_device(&rvdev->pdev->dev);
>> }
>>
>> /**
>> @@ -365,7 +366,7 @@ static void rproc_virtio_dev_release(struct device *dev)
>> static int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
>> {
>> struct rproc *rproc = rvdev->rproc;
>> - struct device *dev = &rvdev->dev;
>> + struct device *dev = &rvdev->pdev->dev;
>> struct virtio_device *vdev;
>> struct rproc_mem_entry *mem;
>> int ret;
>> @@ -436,17 +437,15 @@ static int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
>> vdev->dev.release = rproc_virtio_dev_release;
>>
>> /*
>> - * We're indirectly making a non-temporary copy of the rproc pointer
>> + * We're indirectly making a non-temporary copy of the rvdev pointer
>> * here, because drivers probed with this vdev will indirectly
>> * access the wrapping rproc.
>> *
>> - * Therefore we must increment the rproc refcount here, and decrement
>> + * Therefore we must increment the rvdev refcount here, and decrement
>> * it _only_ when the vdev is released.
>> */
>> - get_device(&rproc->dev);
>> + get_device(dev);
>>
>> - /* Reference the vdev and vring allocations */
>> - kref_get(&rvdev->refcount);
>>
>> ret = register_virtio_device(vdev);
>> if (ret) {
>> @@ -488,57 +487,33 @@ static int rproc_vdev_do_start(struct rproc_subdev *subdev)
>> static void rproc_vdev_do_stop(struct rproc_subdev *subdev, bool crashed)
>> {
>> struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
>> + struct device *dev = &rvdev->pdev->dev;
>> int ret;
>>
>> - ret = device_for_each_child(&rvdev->dev, NULL, rproc_remove_virtio_dev);
>> + ret = device_for_each_child(dev, NULL, rproc_remove_virtio_dev);
>> if (ret)
>> - dev_warn(&rvdev->dev, "can't remove vdev child device: %d\n", ret);
>> -}
>> -
>> -/**
>> - * 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);
>> + dev_warn(dev, "can't remove vdev child device: %d\n", ret);
>> }
>>
>> -int rproc_rvdev_add_device(struct rproc_vdev *rvdev)
>> +static int rproc_rvdev_add_device(struct rproc_vdev *rvdev)
>> {
>> struct rproc *rproc = rvdev->rproc;
>> - char name[16];
>> + struct device *dev = &rvdev->pdev->dev;
>> int ret;
>>
>> - snprintf(name, sizeof(name), "vdev%dbuffer", rvdev->index);
>> - rvdev->dev.parent = &rproc->dev;
>> - ret = copy_dma_range_map(&rvdev->dev, rproc->dev.parent);
>> + ret = copy_dma_range_map(dev, rproc->dev.parent);
>> if (ret)
>> return ret;
>>
>> - 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);
>>
>> - ret = device_register(&rvdev->dev);
>> - if (ret) {
>> - put_device(&rvdev->dev);
>> - return ret;
>> - }
>> /* Make device dma capable by inheriting from parent's capabilities */
>> - set_dma_ops(&rvdev->dev, get_dma_ops(rproc->dev.parent));
>> + set_dma_ops(dev, get_dma_ops(rproc->dev.parent));
>>
>> - ret = dma_coerce_mask_and_coherent(&rvdev->dev,
>> - dma_get_mask(rproc->dev.parent));
>> + ret = dma_coerce_mask_and_coherent(dev, dma_get_mask(rproc->dev.parent));
>> if (ret) {
>> - dev_warn(&rvdev->dev,
>> - "Failed to set DMA mask %llx. Trying to continue... %x\n",
>> + dev_warn(dev, "Failed to set DMA mask %llx. Trying to continue... %x\n",
>> dma_get_mask(rproc->dev.parent), ret);
>> + return ret;
>> }
>>
>> rproc_register_rvdev(rvdev);
>> @@ -548,30 +523,9 @@ int rproc_rvdev_add_device(struct rproc_vdev *rvdev)
>>
>> rproc_add_subdev(rproc, &rvdev->subdev);
>>
>> - return 0;
>> -}
>> -
>> -static void rproc_rvdev_remove_device(struct rproc_vdev *rvdev)
>> -{
>> - struct rproc *rproc = rvdev->rproc;
>> -
>> - rproc_remove_subdev(rproc, &rvdev->subdev);
>> - rproc_unregister_rvdev(rvdev);
>> - device_unregister(&rvdev->dev);
>> -}
>> -
>> -void rproc_vdev_release(struct kref *ref)
>> -{
>> - struct rproc_vdev *rvdev = container_of(ref, struct rproc_vdev, refcount);
>> - struct rproc_vring *rvring;
>> - int id;
>> + dev_dbg(dev, "virtio dev %d added\n", rvdev->index);
>>
>> - for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
>> - rvring = &rvdev->vring[id];
>> - rproc_free_vring(rvring);
>> - }
>> -
>> - rproc_rvdev_remove_device(rvdev);
>> + return 0;
>> }
>>
>> /**
>> @@ -590,8 +544,7 @@ rproc_virtio_register_device(struct rproc *rproc, struct rproc_vdev_data *vdev_d
>> pdev = platform_device_register_data(dev, "rproc-virtio", vdev_data->index, vdev_data,
>> sizeof(*vdev_data));
>> if (PTR_ERR_OR_ZERO(pdev)) {
>> - dev_err(rproc->dev.parent,
>> - "failed to create rproc-virtio device\n");
>> + dev_err(rproc->dev.parent, "failed to create rproc-virtio device\n");
>> }
>>
>> return pdev;
>> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
>> index 542a3d4664f2..7951a3e2b62a 100644
>> --- a/include/linux/remoteproc.h
>> +++ b/include/linux/remoteproc.h
>> @@ -614,10 +614,8 @@ struct rproc_vring {
>>
>> /**
>> * struct rproc_vdev - remoteproc state for a supported virtio device
>> - * @refcount: reference counter for the vdev and vring allocations
>> * @subdev: handle for registering the vdev as a rproc subdevice
>> * @pdev: remoteproc virtio platform device
>> - * @dev: device struct used for reference count semantics
>> * @id: virtio device id (as in virtio_ids.h)
>> * @node: list node
>> * @rproc: the rproc handle
>> @@ -626,11 +624,9 @@ struct rproc_vring {
>> * @index: vdev position versus other vdev declared in resource table
>> */
>> struct rproc_vdev {
>> - struct kref refcount;
>>
>> struct rproc_subdev subdev;
>> struct platform_device *pdev;
>> - struct device dev;
>>
>> unsigned int id;
>> struct list_head node;
>> --
>> 2.17.1
>>