by Tinghan Shen

[permalink] [raw]

Subject: Re: [PATCH v15 07/13] remoteproc: mediatek: Probe SCP cluster on multi-core SCP

Hi Mathieu,

On Tue, 2023-07-25 at 13:59 -0600, Mathieu Poirier wrote:
> On Fri, Jul 21, 2023 at 10:41:26AM +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 <[email protected]>
> > Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
> > ---
> > drivers/remoteproc/mtk_scp.c | 118 +++++++++++++++++++++++++++++++++--
> > 1 file changed, 113 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
> > index d67dcabdab9e..34095a461e15 100644
> > --- a/drivers/remoteproc/mtk_scp.c
> > +++ b/drivers/remoteproc/mtk_scp.c
> > @@ -855,7 +855,8 @@ 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;
> > @@ -878,7 +879,7 @@ 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;
> > scp->cluster = scp_cluster;
> > platform_set_drvdata(pdev, scp);
> >
> > @@ -951,15 +952,15 @@ static void scp_free(struct mtk_scp *scp)
> > mutex_destroy(&scp->send_lock);
> > }
> >
> > -static int scp_cluster_init(struct platform_device *pdev,
> > - struct mtk_scp_of_cluster *scp_cluster)
> > +static int scp_add_single_core(struct platform_device *pdev,
> > + struct mtk_scp_of_cluster *scp_cluster)
> > {
> > struct device *dev = &pdev->dev;
> > struct list_head *scp_list = &scp_cluster->mtk_scp_list;
> > struct mtk_scp *scp;
> > int ret;
> >
> > - scp = scp_rproc_init(pdev, scp_cluster);
> > + scp = scp_rproc_init(pdev, scp_cluster, of_device_get_match_data(dev));
> > if (IS_ERR(scp))
> > return PTR_ERR(scp);
> >
> > @@ -975,6 +976,102 @@ static int scp_cluster_init(struct platform_device *pdev,
> > return 0;
> > }
> >
> > +static int scp_add_multi_core(struct platform_device *pdev,
> > + struct mtk_scp_of_cluster *scp_cluster)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct device_node *np = dev_of_node(dev);
> > + struct platform_device *cpdev;
> > + struct device_node *child;
> > + struct list_head *scp_list = &scp_cluster->mtk_scp_list;
> > + const struct mtk_scp_of_data **cluster_of_data;
> > + struct mtk_scp *scp, *temp;
> > + int core_id = 0;
> > + int ret;
> > +
> > + 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]);
> > + put_device(&cpdev->dev);
> > + if (IS_ERR(scp)) {
> > + ret = PTR_ERR(scp);
> > + dev_err(dev, "Failed to initialize core %d rproc\n", core_id);
> > + of_node_put(child);
> > + goto init_fail;
> > + }
> > +
> > + ret = rproc_add(scp->rproc);
> > + if (ret) {
> > + dev_err(dev, "Failed to add rproc of core %d\n", core_id);
> > + of_node_put(child);
> > + scp_free(scp);
> > + goto init_fail;
> > + }
> > +
> > + list_add_tail(&scp->elem, scp_list);
> > + core_id++;
> > + }
> > +
> > + platform_set_drvdata(pdev, list_first_entry(scp_list, struct mtk_scp, elem));
>
> (sigh)
>
> Why is list_first_entry() used here rather than just @scp? What is the purpose
> of using the list API?

I thought it would be more consistent to use the head node when removing the scp drvier.
I'll do what you suggest.

Best regards,
TingHan

>
> > +
> > + return 0;
> > +
> > +init_fail:
> > + list_for_each_entry_safe_reverse(scp, temp, scp_list, elem) {
> > + list_del(&scp->elem);
> > + rproc_del(scp->rproc);
> > + scp_free(scp);
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +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_of_cluster *scp_cluster)
> > +{
> > + int ret;
> > +
> > + ret = scp_is_single_core(pdev);
> > + if (ret < 0)
> > + return ret;
> > +
> > + if (ret)
> > + ret = scp_add_single_core(pdev, scp_cluster);
> > + else
> > + ret = scp_add_multi_core(pdev, scp_cluster);
> > +
> > + return ret;
> > +}
> > +
> > static int scp_probe(struct platform_device *pdev)
> > {
> > struct device *dev = &pdev->dev;
> > @@ -1007,6 +1104,10 @@ static int scp_probe(struct platform_device *pdev)
> >
> > INIT_LIST_HEAD(&scp_cluster->mtk_scp_list);
> >
> > + 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, scp_cluster);
> > if (ret)
> > return ret;
> > @@ -1101,12 +1202,19 @@ 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