Re: [PATCH v6 8/8] rpmsg: Turn name service into a stand alone driver

Arnaud POULIQUEN
2020-11-19T14:53:12Z

Hi Mathieu,

On 11/18/20 10:37 PM, Mathieu Poirier wrote:
> From: Arnaud Pouliquen <arnaud.pouliquen@st.com>
>
> Make the RPMSG name service announcement a stand alone driver so that it
> can be reused by other subsystems. It is also the first step in making the
> functionatlity transport independent, i.e that is not tied to virtIO.
>
> Co-developed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> Co-developed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
> Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
> ---
> drivers/rpmsg/Kconfig | 9 +++
> drivers/rpmsg/Makefile | 1 +
> drivers/rpmsg/rpmsg_ns.c | 126 +++++++++++++++++++++++++++++++
> drivers/rpmsg/virtio_rpmsg_bus.c | 86 +++++----------------
> include/linux/rpmsg/ns.h | 3 +
> 5 files changed, 158 insertions(+), 67 deletions(-)
> create mode 100644 drivers/rpmsg/rpmsg_ns.c
>
> diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
> index f96716893c2a..0b4407abdf13 100644
> --- a/drivers/rpmsg/Kconfig
> +++ b/drivers/rpmsg/Kconfig
> @@ -15,6 +15,14 @@ config RPMSG_CHAR
> in /dev. They make it possible for user-space programs to send and
> receive rpmsg packets.
>
> +config RPMSG_NS
> + tristate "RPMSG name service announcement"
> + depends on RPMSG
> + help
> + Say Y here to enable the support of the name service announcement
> + channel that probes the associated RPMsg device on remote endpoint
> + service announcement.
> +
> config RPMSG_MTK_SCP
> tristate "MediaTek SCP"
> depends on MTK_SCP
> @@ -62,6 +70,7 @@ config RPMSG_VIRTIO
> tristate "Virtio RPMSG bus driver"
> depends on HAS_DMA
> select RPMSG
> + select RPMSG_NS
> select VIRTIO
>
> endmenu
> diff --git a/drivers/rpmsg/Makefile b/drivers/rpmsg/Makefile
> index ffe932ef6050..8d452656f0ee 100644
> --- a/drivers/rpmsg/Makefile
> +++ b/drivers/rpmsg/Makefile
> @@ -1,6 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_RPMSG) += rpmsg_core.o
> obj-$(CONFIG_RPMSG_CHAR) += rpmsg_char.o
> +obj-$(CONFIG_RPMSG_NS) += rpmsg_ns.o
> obj-$(CONFIG_RPMSG_MTK_SCP) += mtk_rpmsg.o
> qcom_glink-objs := qcom_glink_native.o qcom_glink_ssr.o
> obj-$(CONFIG_RPMSG_QCOM_GLINK) += qcom_glink.o
> diff --git a/drivers/rpmsg/rpmsg_ns.c b/drivers/rpmsg/rpmsg_ns.c
> new file mode 100644
> index 000000000000..66a22497d316
> --- /dev/null
> +++ b/drivers/rpmsg/rpmsg_ns.c
> @@ -0,0 +1,126 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) STMicroelectronics 2020 - All Rights Reserved
> + */
> +#include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/rpmsg.h>
> +#include <linux/rpmsg/ns.h>
> +
> +#include "rpmsg_internal.h"
> +
> +/**
> + * rpmsg_ns_register_device() - register name service device based on rpdev
> + * @rpdev: prepared rpdev to be used for creating endpoints
> + *
> + * This function wraps rpmsg_register_device() preparing the rpdev for use as
> + * basis for the rpmsg name service device.
> + */
> +int rpmsg_ns_register_device(struct rpmsg_device *rpdev)
> +{
> + strcpy(rpdev->id.name, "rpmsg_ns");
> + rpdev->driver_override = "rpmsg_ns";
> + rpdev->src = RPMSG_NS_ADDR;
> + rpdev->dst = RPMSG_NS_ADDR;
> +
> + return rpmsg_register_device(rpdev);
> +}
> +EXPORT_SYMBOL(rpmsg_ns_register_device);
> +
> +/* invoked when a name service announcement arrives */
> +static int rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len,
> + void *priv, u32 src)
> +{
> + struct rpmsg_ns_msg *msg = data;
> + struct rpmsg_device *newch;
> + struct rpmsg_channel_info chinfo;
> + struct device *dev = rpdev->dev.parent;
> + int ret;
> +
> +#if defined(CONFIG_DYNAMIC_DEBUG)
> + dynamic_hex_dump("NS announcement: ", DUMP_PREFIX_NONE, 16, 1,
> + data, len, true);
> +#endif
> +
> + if (len != sizeof(*msg)) {
> + dev_err(dev, "malformed ns msg (%d)\n", len);
> + return -EINVAL;
> + }
> +
> + /* don't trust the remote processor for null terminating the name */
> + msg->name[RPMSG_NAME_SIZE - 1] = '\0';
> +
> + strncpy(chinfo.name, msg->name, sizeof(chinfo.name));
> + chinfo.src = RPMSG_ADDR_ANY;
> + chinfo.dst = rpmsg32_to_cpu(rpdev, msg->addr);
> +
> + dev_info(dev, "%sing channel %s addr 0x%x\n",
> + rpmsg32_to_cpu(rpdev, msg->flags) & RPMSG_NS_DESTROY ?
> + "destroy" : "creat", msg->name, chinfo.dst);
> +
> + if (rpmsg32_to_cpu(rpdev, msg->flags) & RPMSG_NS_DESTROY) {
> + ret = rpmsg_release_channel(rpdev, &chinfo);
> + if (ret)
> + dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret);
> + } else {
> + newch = rpmsg_create_channel(rpdev, &chinfo);
> + if (!newch)
> + dev_err(dev, "rpmsg_create_channel failed\n");
> + }
> +
> + return 0;
> +}
> +
> +static int rpmsg_ns_probe(struct rpmsg_device *rpdev)
> +{
> + struct rpmsg_endpoint *ns_ept;
> + struct rpmsg_channel_info ns_chinfo = {
> + .src = RPMSG_NS_ADDR,
> + .dst = RPMSG_NS_ADDR,
> + .name = "name_service",
> + };
> +
> + /*
> + * Create the NS announcement service endpoint associated to the RPMsg
> + * device. The endpoint will be automatically destroyed when the RPMsg
> + * device will be deleted.
> + */
> + ns_ept = rpmsg_create_ept(rpdev, rpmsg_ns_cb, NULL, ns_chinfo);
> + if (!ns_ept) {
> + dev_err(&rpdev->dev, "failed to create the ns ept\n");
> + return -ENOMEM;
> + }
> + rpdev->ept = ns_ept;
> +
> + return 0;
> +}
> +
> +static struct rpmsg_driver rpmsg_ns_driver = {
> + .drv.name = KBUILD_MODNAME,
> + .probe = rpmsg_ns_probe,
> +};
> +
> +static int rpmsg_ns_init(void)
> +{
> + int ret;
> +
> + ret = register_rpmsg_driver(&rpmsg_ns_driver);
> + if (ret < 0)
> + pr_err("%s: Failed to register rpmsg driver\n", __func__);
> +
> + return ret;
> +}
> +postcore_initcall(rpmsg_ns_init);
> +
> +static void rpmsg_ns_exit(void)
> +{
> + unregister_rpmsg_driver(&rpmsg_ns_driver);
> +}
> +module_exit(rpmsg_ns_exit);
> +
> +MODULE_DESCRIPTION("Name service announcement rpmsg driver");
> +MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
> +MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
> index 6ec299f7f790..338f16c6563d 100644
> --- a/drivers/rpmsg/virtio_rpmsg_bus.c
> +++ b/drivers/rpmsg/virtio_rpmsg_bus.c
> @@ -49,7 +49,6 @@
> * @endpoints_lock: lock of the endpoints set
> * @sendq: wait queue of sending contexts waiting for a tx buffers
> * @sleepers: number of senders that are waiting for a tx buffer
> - * @ns_ept: the bus's name service endpoint
> *
> * This structure stores the rpmsg state of a given virtio remote processor
> * device (there might be several virtio proc devices for each physical
> @@ -68,7 +67,6 @@ struct virtproc_info {
> struct mutex endpoints_lock;
> wait_queue_head_t sendq;
> atomic_t sleepers;
> - struct rpmsg_endpoint *ns_ept;
> };
>
> /* The feature bitmap for virtio rpmsg */
> @@ -815,69 +813,14 @@ static void rpmsg_xmit_done(struct virtqueue *svq)
> wake_up_interruptible(&vrp->sendq);
> }
>
> -/* invoked when a name service announcement arrives */
> -static int rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len,
> - void *priv, u32 src)
> -{
> - struct rpmsg_ns_msg *msg = data;
> - struct rpmsg_device *newch;
> - struct rpmsg_channel_info chinfo;
> - struct virtproc_info *vrp = priv;
> - struct device *dev = &vrp->vdev->dev;
> - bool little_endian = virtio_is_little_endian(vrp->vdev);
> - int ret;
> -
> -#if defined(CONFIG_DYNAMIC_DEBUG)
> - dynamic_hex_dump("NS announcement: ", DUMP_PREFIX_NONE, 16, 1,
> - data, len, true);
> -#endif
> -
> - if (len != sizeof(*msg)) {
> - dev_err(dev, "malformed ns msg (%d)\n", len);
> - return -EINVAL;
> - }
> -
> - /*
> - * the name service ept does _not_ belong to a real rpmsg channel,
> - * and is handled by the rpmsg bus itself.
> - * for sanity reasons, make sure a valid rpdev has _not_ sneaked
> - * in somehow.
> - */
> - if (rpdev) {
> - dev_err(dev, "anomaly: ns ept has an rpdev handle\n");
> - return -EINVAL;
> - }
> -
> - /* don't trust the remote processor for null terminating the name */
> - msg->name[RPMSG_NAME_SIZE - 1] = '\0';
> -
> - strncpy(chinfo.name, msg->name, sizeof(chinfo.name));
> - chinfo.src = RPMSG_ADDR_ANY;
> - chinfo.dst = __rpmsg32_to_cpu(little_endian, msg->addr);
> -
> - dev_info(dev, "%sing channel %s addr 0x%x\n",
> - __rpmsg32_to_cpu(little_endian, msg->flags) & RPMSG_NS_DESTROY ?
> - "destroy" : "creat", msg->name, chinfo.dst);
> -
> - if (__rpmsg32_to_cpu(little_endian, msg->flags) & RPMSG_NS_DESTROY) {
> - ret = rpmsg_unregister_device(&vrp->vdev->dev, &chinfo);
> - if (ret)
> - dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret);
> - } else {
> - newch = __rpmsg_create_channel(vrp, &chinfo);
> - if (!newch)
> - dev_err(dev, "rpmsg_create_channel failed\n");
> - }
> -
> - return 0;
> -}
> -
> static int rpmsg_probe(struct virtio_device *vdev)
> {
> vq_callback_t *vq_cbs[] = { rpmsg_recv_done, rpmsg_xmit_done };
> static const char * const names[] = { "input", "output" };
> struct virtqueue *vqs[2];
> struct virtproc_info *vrp;
> + struct virtio_rpmsg_channel *vch;
> + struct rpmsg_device *rpdev_ns;
> void *bufs_va;
> int err = 0, i;
> size_t total_buf_space;
> @@ -953,14 +896,26 @@ static int rpmsg_probe(struct virtio_device *vdev)
>
> /* if supported by the remote processor, enable the name service */
> if (virtio_has_feature(vdev, VIRTIO_RPMSG_F_NS)) {
> - /* a dedicated endpoint handles the name service msgs */
> - vrp->ns_ept = __rpmsg_create_ept(vrp, NULL, rpmsg_ns_cb,
> - vrp, RPMSG_NS_ADDR);
> - if (!vrp->ns_ept) {
> - dev_err(&vdev->dev, "failed to create the ns ept\n");
> + vch = kzalloc(sizeof(*vch), GFP_KERNEL);
> + if (!vch) {
> err = -ENOMEM;
> goto free_coherent;
> }
> +
> + /* Link the channel to our vrp */
> + vch->vrp = vrp;
> +
> + /* Assign public information to the rpmsg_device */
> + rpdev_ns = &vch->rpdev;
> + rpdev_ns->ops = &virtio_rpmsg_ops;
> + rpdev_ns->little_endian = virtio_is_little_endian(vrp->vdev);
> +
> + rpdev_ns->dev.parent = &vrp->vdev->dev;
> + rpdev_ns->dev.release = virtio_rpmsg_release_device;
> +
> + err = rpmsg_ns_register_device(rpdev_ns);
> + if (err)
> + goto free_coherent;

As Guennadi mentionned in a previous mail
a kfree(vch) is missing on error

@@ -949,10 +949,11 @@ static int rpmsg_probe(struct virtio_device *vdev)
dev_info(&vdev->dev, "rpmsg host is online\n");

return 0;

free_coherent:
+ kfree(vch);
dma_free_coherent(vdev->dev.parent, total_buf_space,
bufs_va, vrp->bufs_dma);
vqs_del:

Otherwise i tested this series successfully.

Thanks,
Arnaud

> }
>
> /*
> @@ -1013,9 +968,6 @@ static void rpmsg_remove(struct virtio_device *vdev)
> if (ret)
> dev_warn(&vdev->dev, "can't remove rpmsg device: %d\n", ret);
>
> - if (vrp->ns_ept)
> - __rpmsg_destroy_ept(vrp, vrp->ns_ept);
> -
> idr_destroy(&vrp->endpoints);
>
> vdev->config->del_vqs(vrp->vdev);
> diff --git a/include/linux/rpmsg/ns.h b/include/linux/rpmsg/ns.h
> index 73ecc91dc26f..a7804edd6d58 100644
> --- a/include/linux/rpmsg/ns.h
> +++ b/include/linux/rpmsg/ns.h
> @@ -4,6 +4,7 @@
> #define _LINUX_RPMSG_NS_H
>
> #include <linux/mod_devicetable.h>
> +#include <linux/rpmsg.h>
> #include <linux/rpmsg/byteorder.h>
> #include <linux/types.h>
>
> @@ -39,4 +40,6 @@ enum rpmsg_ns_flags {
> /* Address 53 is reserved for advertising remote services */
> #define RPMSG_NS_ADDR (53)
>
> +int rpmsg_ns_register_device(struct rpmsg_device *rpdev);
> +
> #endif
>