Re: [PATCH v2] soc: xilinx: Add cb event for subsystem restart

[Michal Simek]

On 4/24/24 14:49, Jay Buddhabhatti wrote:
> Add support to register subsystem restart events from firmware for Versal
> and Versal NET platforms. This event is received when firmware requests
> for subsystem restart. After receiving this event, the kernel needs to be
> restarted.
>
> Signed-off-by: Jay Buddhabhatti <jay.buddhabhatti@xxxxxxx>
> ---
> V1: https://lore.kernel.org/lkml/20240424095937.2448-1-jay.buddhabhatti@xxxxxxx/
> V1->V2: Updated copyright header in xlnx-event-manager.h
> ---
>   drivers/soc/xilinx/zynqmp_power.c           | 151 +++++++++++++++++---
>   include/linux/firmware/xlnx-event-manager.h |  10 ++
>   2 files changed, 141 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/soc/xilinx/zynqmp_power.c b/drivers/soc/xilinx/zynqmp_power.c
> index 8570ab1a6857..c193daf04a0a 100644
> --- a/drivers/soc/xilinx/zynqmp_power.c
> +++ b/drivers/soc/xilinx/zynqmp_power.c
> @@ -31,9 +31,27 @@ struct zynqmp_pm_work_struct {
>   	u32 args[CB_ARG_CNT];
>   };
>   
> -static struct zynqmp_pm_work_struct *zynqmp_pm_init_suspend_work;
> +/**
> + * struct zynqmp_pm_event_info - event related information
> + * @cb_fun:	Function pointer to store the callback function.
> + * @cb_type:	Type of callback from pm_api_cb_id,
> + *			PM_NOTIFY_CB - for Error Events,
> + *			PM_INIT_SUSPEND_CB - for suspend callback.
> + * @node_id:	Node-Id related to event.
> + * @event:	Event Mask for the Error Event.
> + * @wake:	Flag specifying whether the subsystem should be woken upon
> + *		event notification.
> + */
> +struct zynqmp_pm_event_info {
> +	event_cb_func_t cb_fun;
> +	enum pm_api_cb_id cb_type;
> +	u32 node_id;
> +	u32 event;
> +	bool wake;
> +};
> +
> +static struct zynqmp_pm_work_struct *zynqmp_pm_init_suspend_work, *zynqmp_pm_init_restart_work;
>   static struct mbox_chan *rx_chan;
> -static bool event_registered;
>   
>   enum pm_suspend_mode {
>   	PM_SUSPEND_MODE_FIRST = 0,
> @@ -55,6 +73,19 @@ static void zynqmp_pm_get_callback_data(u32 *buf)
>   	zynqmp_pm_invoke_fn(GET_CALLBACK_DATA, buf, 0);
>   }
>   
> +static void subsystem_restart_event_callback(const u32 *payload, void *data)
> +{
> +	/* First element is callback API ID, others are callback arguments */
> +	if (work_pending(&zynqmp_pm_init_restart_work->callback_work))
> +		return;
> +
> +	/* Copy callback arguments into work's structure */
> +	memcpy(zynqmp_pm_init_restart_work->args, &payload[0],
> +	       sizeof(zynqmp_pm_init_restart_work->args));
> +
> +	queue_work(system_unbound_wq, &zynqmp_pm_init_restart_work->callback_work);
> +}
> +
>   static void suspend_event_callback(const u32 *payload, void *data)
>   {
>   	/* First element is callback API ID, others are callback arguments */
> @@ -120,6 +151,37 @@ static void ipi_receive_callback(struct mbox_client *cl, void *data)
>   	}
>   }
>   
> +/**
> + * zynqmp_pm_subsystem_restart_work_fn - Initiate Subsystem restart
> + * @work:	Pointer to work_struct
> + *
> + * Bottom-half of PM callback IRQ handler.
> + */
> +static void zynqmp_pm_subsystem_restart_work_fn(struct work_struct *work)
> +{
> +	int ret;
> +	struct zynqmp_pm_work_struct *pm_work = container_of(work, struct zynqmp_pm_work_struct,
> +							     callback_work);
> +
> +	/* First element is callback API ID, others are callback arguments */
> +	if (pm_work->args[0] == PM_NOTIFY_CB) {
> +		if (pm_work->args[2] == EVENT_SUBSYSTEM_RESTART) {
> +			ret = zynqmp_pm_system_shutdown(ZYNQMP_PM_SHUTDOWN_TYPE_SETSCOPE_ONLY,
> +							ZYNQMP_PM_SHUTDOWN_SUBTYPE_SUBSYSTEM);
> +			if (ret) {
> +				pr_err("unable to set shutdown scope\n");
> +				return;
> +			}
> +
> +			kernel_restart(NULL);
> +		} else {
> +			pr_err("%s Unsupported Event - %d\n", __func__, pm_work->args[2]);
> +		}
> +	} else {
> +		pr_err("%s() Unsupported Callback %d\n", __func__, pm_work->args[0]);
> +	}
> +}
> +
>   /**
>    * zynqmp_pm_init_suspend_work_fn - Initialize suspend
>    * @work:	Pointer to work_struct
> @@ -185,10 +247,46 @@ static ssize_t suspend_mode_store(struct device *dev,
>   
>   static DEVICE_ATTR_RW(suspend_mode);
>   
> +static void unregister_event(struct device *dev, void *res)
> +{
> +	struct zynqmp_pm_event_info *event_info = res;
> +
> +	xlnx_unregister_event(event_info->cb_type, event_info->node_id,
> +			      event_info->event, event_info->cb_fun, NULL);
> +}
> +
> +static int register_event(struct device *dev, const enum pm_api_cb_id cb_type, const u32 node_id,
> +			  const u32 event, const bool wake, event_cb_func_t cb_fun)
> +{
> +	int ret;
> +	struct zynqmp_pm_event_info *event_info;
> +
> +	event_info = devres_alloc(unregister_event, sizeof(struct zynqmp_pm_event_info),
> +				  GFP_KERNEL);
> +	if (!event_info)
> +		return -ENOMEM;
> +
> +	event_info->cb_type = cb_type;
> +	event_info->node_id = node_id;
> +	event_info->event = event;
> +	event_info->wake = wake;
> +	event_info->cb_fun = cb_fun;
> +
> +	ret = xlnx_register_event(event_info->cb_type, event_info->node_id,
> +				  event_info->event, event_info->wake, event_info->cb_fun, NULL);
> +	if (ret) {
> +		devres_free(event_info);
> +		return ret;
> +	}
> +
> +	devres_add(dev, event_info);
> +	return 0;
> +}
> +
>   static int zynqmp_pm_probe(struct platform_device *pdev)
>   {
>   	int ret, irq;
> -	u32 pm_api_version;
> +	u32 pm_api_version, pm_family_code, pm_sub_family_code, node_id;
>   	struct mbox_client *client;
>   
>   	ret = zynqmp_pm_get_api_version(&pm_api_version);
> @@ -206,21 +304,43 @@ static int zynqmp_pm_probe(struct platform_device *pdev)
>   	 * is not available to use) or -ENODEV(Xilinx Event Manager not compiled),
>   	 * then use ipi-mailbox or interrupt method.
>   	 */
> -	ret = xlnx_register_event(PM_INIT_SUSPEND_CB, 0, 0, false,
> -				  suspend_event_callback, NULL);
> +	ret = register_event(&pdev->dev, PM_INIT_SUSPEND_CB, 0, 0, false,
> +			     suspend_event_callback);
>   	if (!ret) {
>   		zynqmp_pm_init_suspend_work = devm_kzalloc(&pdev->dev,
>   							   sizeof(struct zynqmp_pm_work_struct),
>   							   GFP_KERNEL);
> -		if (!zynqmp_pm_init_suspend_work) {
> -			xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0,
> -					      suspend_event_callback, NULL);
> +		if (!zynqmp_pm_init_suspend_work)
>   			return -ENOMEM;
> -		}
> -		event_registered = true;
>   
>   		INIT_WORK(&zynqmp_pm_init_suspend_work->callback_work,
>   			  zynqmp_pm_init_suspend_work_fn);
> +
> +		ret = zynqmp_pm_get_family_info(&pm_family_code, &pm_sub_family_code);
> +		if (ret < 0)
> +			return ret;
> +
> +		if (pm_sub_family_code == VERSALNET_SUB_FAMILY_CODE)
> +			node_id = PM_DEV_ACPU_0_0;
> +		else
> +			node_id = PM_DEV_ACPU_0;
> +
> +		ret = register_event(&pdev->dev, PM_NOTIFY_CB, node_id, EVENT_SUBSYSTEM_RESTART,
> +				     false, subsystem_restart_event_callback);
> +		if (ret) {
> +			dev_err(&pdev->dev, "Failed to Register with Xilinx Event manager %d\n",
> +				ret);
> +			return ret;
> +		}
> +
> +		zynqmp_pm_init_restart_work = devm_kzalloc(&pdev->dev,
> +							   sizeof(struct zynqmp_pm_work_struct),
> +							   GFP_KERNEL);
> +		if (!zynqmp_pm_init_restart_work)
> +			return -ENOMEM;
> +
> +		INIT_WORK(&zynqmp_pm_init_restart_work->callback_work,
> +			  zynqmp_pm_subsystem_restart_work_fn);
>   	} else if (ret != -EACCES && ret != -ENODEV) {
>   		dev_err(&pdev->dev, "Failed to Register with Xilinx Event manager %d\n", ret);
>   		return ret;
> @@ -267,15 +387,8 @@ static int zynqmp_pm_probe(struct platform_device *pdev)
>   	}
>   
>   	ret = sysfs_create_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
> -	if (ret) {
> -		if (event_registered) {
> -			xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback,
> -					      NULL);
> -			event_registered = false;
> -		}
> -		dev_err(&pdev->dev, "unable to create sysfs interface\n");
> +	if (ret)
>   		return ret;
> -	}
>   
>   	return 0;
>   }
> @@ -283,8 +396,6 @@ static int zynqmp_pm_probe(struct platform_device *pdev)
>   static void zynqmp_pm_remove(struct platform_device *pdev)
>   {
>   	sysfs_remove_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
> -	if (event_registered)
> -		xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback, NULL);
>   
>   	if (!rx_chan)
>   		mbox_free_channel(rx_chan);
> diff --git a/include/linux/firmware/xlnx-event-manager.h b/include/linux/firmware/xlnx-event-manager.h
> index 82e8254b0f80..645dd34155e6 100644
> --- a/include/linux/firmware/xlnx-event-manager.h
> +++ b/include/linux/firmware/xlnx-event-manager.h
> @@ -1,4 +1,9 @@
>   /* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Xilinx Event Management Driver
> + *
> + * Copyright (C) 2024, Advanced Micro Devices, Inc.
> + */
>   
>   #ifndef _FIRMWARE_XLNX_EVENT_MANAGER_H_
>   #define _FIRMWARE_XLNX_EVENT_MANAGER_H_
> @@ -7,6 +12,11 @@
>   
>   #define CB_MAX_PAYLOAD_SIZE	(4U) /*In payload maximum 32bytes */
>   
> +#define EVENT_SUBSYSTEM_RESTART		(4U)
> +
> +#define PM_DEV_ACPU_0_0			(0x1810c0afU)
> +#define PM_DEV_ACPU_0			(0x1810c003U)
> +
>   /************************** Exported Function *****************************/
>   
>   typedef void (*event_cb_func_t)(const u32 *payload, void *data);

Applied.
M