Re: [PATCH v4 13/14] gunyah: rsc_mgr: Add auxiliary devices for console

Greg Kroah-Hartman
2022-09-30T12:19:23Z

On Wed, Sep 28, 2022 at 12:56:32PM -0700, Elliot Berman wrote:
> Gunyah resource manager exposes a concrete functionalities which
> complicate a single resource manager driver.

I am sorry, but I do not understand this sentance. What is so
complicated about individual devices being created? Where are they
created? What bus?

Use auxiliary bus
> to help split high level functions for the resource manager and keep the
> primary resource manager driver focused on the RPC with RM itself.
> Delegate Resource Manager's console functionality to the auxiliary bus.
>
> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
> ---
> drivers/virt/gunyah/Kconfig | 1 +
> drivers/virt/gunyah/rsc_mgr.c | 21 +++++++++++++++++++++
> 2 files changed, 22 insertions(+)
>
> diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
> index 78deed3c4562..610c8586005b 100644
> --- a/drivers/virt/gunyah/Kconfig
> +++ b/drivers/virt/gunyah/Kconfig
> @@ -17,6 +17,7 @@ config GUNYAH_RESORUCE_MANAGER
> tristate "Gunyah Resource Manager"
> select MAILBOX
> select GUNYAH_MESSAGE_QUEUES
> + select AUXILIARY_BUS
> default y
> help
> The resource manager (RM) is a privileged application VM supporting
> diff --git a/drivers/virt/gunyah/rsc_mgr.c b/drivers/virt/gunyah/rsc_mgr.c
> index 7f7e89a6436b..435fe0149915 100644
> --- a/drivers/virt/gunyah/rsc_mgr.c
> +++ b/drivers/virt/gunyah/rsc_mgr.c
> @@ -16,6 +16,7 @@
> #include <linux/notifier.h>
> #include <linux/workqueue.h>
> #include <linux/completion.h>
> +#include <linux/auxiliary_bus.h>
> #include <linux/gunyah_rsc_mgr.h>
> #include <linux/platform_device.h>
>
> @@ -98,6 +99,8 @@ struct gh_rsc_mgr {
> struct mutex send_lock;
>
> struct work_struct recv_work;
> +
> + struct auxiliary_device console_adev;
> };
>
> static struct gh_rsc_mgr *__rsc_mgr;
> @@ -573,13 +576,31 @@ static int gh_rm_drv_probe(struct platform_device *pdev)
>
> __rsc_mgr = rsc_mgr;
>
> + rsc_mgr->console_adev.dev.parent = &pdev->dev;
> + rsc_mgr->console_adev.name = "console";
> + ret = auxiliary_device_init(&rsc_mgr->console_adev);
> + if (ret)
> + goto err_msgq;
> + ret = auxiliary_device_add(&rsc_mgr->console_adev);
> + if (ret)
> + goto err_console_adev_uninit;
> +
> return 0;
> +
> +err_console_adev_uninit:
> + auxiliary_device_uninit(&rsc_mgr->console_adev);
> +err_msgq:
> + gunyah_msgq_remove(&rsc_mgr->msgq);
> + return ret;
> }

Why can't you just have individual platform devices for the individual
devices your hypervisor exposes?

You control the platform devices, why force them to be shared like this?

thanks,

greg k-h