Re: [PATCH v11 06/11] remoteproc: mediatek: Probe multi-core SCP

Mathieu Poirier
2023-05-12T17:56:33Z

On Wed, May 10, 2023 at 02:37:44PM +0800, Tinghan Shen wrote:
> The difference of single-core SCP and multi-core SCP device tree is
> the presence of child device nodes described SCP cores. The SCP
> driver populates the platform device and checks the child nodes
> to identify whether it's a single-core SCP or a multi-core SCP.
>
> Add the remoteproc instances of multi-core SCP to the SCP cluster list.
> When the SCP driver is removed, it cleanup resources by walking
> through the cluster list.
>
> Signed-off-by: Tinghan Shen <tinghan.shen@mediatek.com>
> ---
> drivers/remoteproc/mtk_scp.c | 135 ++++++++++++++++++++++++++++++-----
> 1 file changed, 117 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
> index ff73c6dd9637..87215a0e145e 100644
> --- a/drivers/remoteproc/mtk_scp.c
> +++ b/drivers/remoteproc/mtk_scp.c
> @@ -864,7 +864,8 @@ static void scp_remove_rpmsg_subdev(struct mtk_scp *scp)
> }
>
> static struct mtk_scp *scp_rproc_init(struct platform_device *pdev,
> - struct mtk_scp_of_cluster *scp_cluster)
> + struct mtk_scp_of_cluster *scp_cluster,
> + const struct mtk_scp_of_data *of_data)
> {
> struct device *dev = &pdev->dev;
> struct device_node *np = dev->of_node;
> @@ -887,7 +888,7 @@ static struct mtk_scp *scp_rproc_init(struct platform_device *pdev,
> scp = rproc->priv;
> scp->rproc = rproc;
> scp->dev = dev;
> - scp->data = of_device_get_match_data(dev);
> + scp->data = of_data;
> platform_device_add_data(pdev, &scp, sizeof(scp));
>
> scp->reg_base = scp_cluster->reg_base;
> @@ -938,10 +939,6 @@ static struct mtk_scp *scp_rproc_init(struct platform_device *pdev,
> goto remove_subdev;
> }
>
> - ret = rproc_add(rproc);
> - if (ret)
> - goto remove_subdev;
> -

This should have been done in the previous patch.

> return scp;
>
> remove_subdev:
> @@ -956,19 +953,116 @@ static struct mtk_scp *scp_rproc_init(struct platform_device *pdev,
> return ERR_PTR(ret);
> }
>
> +static void scp_rproc_free(struct mtk_scp *scp)
> +{
> + int i;
> +
> + scp_remove_rpmsg_subdev(scp);
> + scp_ipi_unregister(scp, SCP_IPI_INIT);
> + scp_unmap_memory_region(scp);
> + for (i = 0; i < SCP_IPI_MAX; i++)
> + mutex_destroy(&scp->ipi_desc[i].lock);
> + mutex_destroy(&scp->send_lock);
> +}
> +
> +static int scp_is_single_core(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct device_node *np = dev_of_node(dev);
> + struct device_node *child;
> +
> + child = of_get_next_available_child(np, NULL);
> + if (!child)
> + return dev_err_probe(dev, -ENODEV, "No child node\n");
> +
> + of_node_put(child);
> + return of_node_name_eq(child, "cros-ec-rpmsg");
> +}
> +
> static int scp_cluster_init(struct platform_device *pdev)
> {
> - struct mtk_scp *scp;
> + struct mtk_scp *scp, *temp;
> struct mtk_scp_of_cluster *scp_cluster = platform_get_drvdata(pdev);
> struct list_head *cluster = &scp_cluster->mtk_scp_cluster;
>
> - scp = scp_rproc_init(pdev, scp_cluster);
> - if (IS_ERR(scp))
> - return PTR_ERR(scp);
> + struct device *dev = &pdev->dev;
> + struct device_node *np = dev_of_node(dev);
> + struct platform_device *cpdev;
> + struct device_node *child;
> + const struct mtk_scp_of_data **cluster_of_data;
> + int core_id = 0;
> + int ret;
> +
> + ret = scp_is_single_core(pdev);
> + if (ret < 0)
> + return ret;
> +
> + if (ret) {
> + dev_dbg(dev, "single-core scp\n");
> +
> + /* When using the SCP node phandle on exported SCP APIs, the drvdata
> + * is expected to be the mtk_scp object, and as a result, it is intended
> + * to be overwritten for single-core SCP usage.
> + */

Is this comment still relevant?

> + scp = scp_rproc_init(pdev, scp_cluster, of_device_get_match_data(dev));
> + if (IS_ERR(scp))
> + return PTR_ERR(scp);
> +
> + list_add_tail(&scp->elem, cluster);

This is getting messy. Please add two new functions, i.e scp_add_single_core()
and scp_add_multi_core().

> + } else {
> + dev_dbg(dev, "multi-core scp\n");
> +
> + cluster_of_data = (const struct mtk_scp_of_data **)of_device_get_match_data(dev);
> +
> + for_each_available_child_of_node(np, child) {
> + if (!cluster_of_data[core_id]) {
> + ret = -EINVAL;
> + dev_err(dev, "Not support core %d\n", core_id);
> + of_node_put(child);
> + goto init_fail;
> + }
> +
> + cpdev = of_find_device_by_node(child);
> + if (!cpdev) {
> + ret = -ENODEV;
> + dev_err(dev, "Not found platform device for core %d\n", core_id);
> + of_node_put(child);
> + goto init_fail;
> + }
> +
> + scp = scp_rproc_init(cpdev, scp_cluster, cluster_of_data[core_id]);
> + if (IS_ERR(scp)) {
> + dev_err(dev, "Failed to initialize core %d rproc\n", core_id);
> + put_device(&cpdev->dev);
> + of_node_put(child);
> + goto init_fail;
> + }
> + list_add_tail(&scp->elem, cluster);
> + put_device(&cpdev->dev);
> +
> + core_id++;
> + }
> + }
>
> - list_add_tail(&scp->elem, cluster);
> + list_for_each_entry_safe_reverse(scp, temp, cluster, elem) {
> + ret = rproc_add(scp->rproc);

Call rproc_add() in the for_each_available_child_of_node() loop above. That way
it if fails you can call scp_rproc_free() right away and jump to init_fail to
deal with the other cores on the list.

> + if (ret)
> + goto add_fail;
> + }
>
> return 0;
> +
> +add_fail:
> + list_for_each_entry_continue(scp, cluster, elem) {
> + rproc_del(scp->rproc);
> + }
> +init_fail:
> + list_for_each_entry_safe_reverse(scp, temp, cluster, elem) {
> + list_del(&scp->elem);
> + scp_rproc_free(scp);
> + }
> +

There are a serious problems with the code in both labels above. I will let you
think about that and I will stop here for this revision.

Mathieu

> + return ret;
> }
>
> static int scp_probe(struct platform_device *pdev)
> @@ -1005,6 +1099,10 @@ static int scp_probe(struct platform_device *pdev)
> INIT_LIST_HEAD(&scp_cluster->mtk_scp_cluster);
> platform_set_drvdata(pdev, scp_cluster);
>
> + ret = devm_of_platform_populate(dev);
> + if (ret)
> + return dev_err_probe(dev, ret, "Failed to populate platform devices\n");
> +
> ret = scp_cluster_init(pdev);
> if (ret)
> return ret;
> @@ -1016,17 +1114,11 @@ static int scp_remove(struct platform_device *pdev)
> {
> struct mtk_scp_of_cluster *scp_cluster = platform_get_drvdata(pdev);
> struct mtk_scp *scp, *temp;
> - int i;
>
> list_for_each_entry_safe_reverse(scp, temp, &scp_cluster->mtk_scp_cluster, elem) {
> list_del(&scp->elem);
> rproc_del(scp->rproc);
> - scp_remove_rpmsg_subdev(scp);
> - scp_ipi_unregister(scp, SCP_IPI_INIT);
> - scp_unmap_memory_region(scp);
> - for (i = 0; i < SCP_IPI_MAX; i++)
> - mutex_destroy(&scp->ipi_desc[i].lock);
> - mutex_destroy(&scp->send_lock);
> + scp_rproc_free(scp);
> }
>
> return 0;
> @@ -1106,12 +1198,19 @@ static const struct mtk_scp_of_data mt8195_of_data_c1 = {
> .host_to_scp_int_bit = MT8195_CORE1_HOST_IPC_INT_BIT,
> };
>
> +static const struct mtk_scp_of_data *mt8195_of_data_cores[] = {
> + &mt8195_of_data,
> + &mt8195_of_data_c1,
> + NULL
> +};
> +
> static const struct of_device_id mtk_scp_of_match[] = {
> { .compatible = "mediatek,mt8183-scp", .data = &mt8183_of_data },
> { .compatible = "mediatek,mt8186-scp", .data = &mt8186_of_data },
> { .compatible = "mediatek,mt8188-scp", .data = &mt8188_of_data },
> { .compatible = "mediatek,mt8192-scp", .data = &mt8192_of_data },
> { .compatible = "mediatek,mt8195-scp", .data = &mt8195_of_data },
> + { .compatible = "mediatek,mt8195-scp-dual", .data = &mt8195_of_data_cores },
> {},
> };
> MODULE_DEVICE_TABLE(of, mtk_scp_of_match);
> --
> 2.18.0
>