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From: Andrew Davis <afd@ti.com>
To: Richard Genoud <richard.genoud@bootlin.com>,
	Bjorn Andersson <andersson@kernel.org>,
	Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: "Philipp Zabel" <p.zabel@pengutronix.de>,
	"Suman Anna" <s-anna@ti.com>,
	"Thomas Petazzoni" <thomas.petazzoni@bootlin.com>,
	"Alexandre Belloni" <alexandre.belloni@bootlin.com>,
	"Udit Kumar" <u-kumar1@ti.com>,
	"Thomas Richard" <thomas.richard@bootlin.com>,
	"Gregory CLEMENT" <gregory.clement@bootlin.com>,
	"Hari Nagalla" <hnagalla@ti.com>,
	"Théo Lebrun" <theo.lebrun@bootlin.com>,
	linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 4/4] remoteproc: k3-r5: support for graceful stop of remote cores
Date: Fri, 28 Jun 2024 17:50:52 -0500	[thread overview]
Message-ID: <33d97f00-dd9a-4643-8210-859c2ab38a97@ti.com> (raw)
In-Reply-To: <20240621150058.319524-5-richard.genoud@bootlin.com>

On 6/21/24 10:00 AM, Richard Genoud wrote:
> Introduce software IPC handshake between the K3-R5 remote proc driver
> and the R5 MCU to gracefully stop/reset the remote core.
> 
> Upon a stop request, K3-R5 remote proc driver sends a RP_MBOX_SHUTDOWN
> mailbox message to the remote R5 core.
> The remote core is expected to:
> - relinquish all the resources acquired through Device Manager (DM)
> - disable its interrupts
> - send back a mailbox acknowledgment RP_MBOX_SHUDOWN_ACK
> - enter WFI state.
> 
> Meanwhile, the K3-R5 remote proc driver does:
> - wait for the RP_MBOX_SHUTDOWN_ACK from the remote core
> - wait for the remote proc to enter WFI state
> - reset the remote core through device manager
> 
> Based on work from: Hari Nagalla <hnagalla@ti.com>
> 
> Signed-off-by: Richard Genoud <richard.genoud@bootlin.com>
> ---
>   drivers/remoteproc/omap_remoteproc.h     |  9 +++++-
>   drivers/remoteproc/ti_k3_r5_remoteproc.c | 40 ++++++++++++++++++++++++
>   2 files changed, 48 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/remoteproc/omap_remoteproc.h b/drivers/remoteproc/omap_remoteproc.h
> index 828e13256c02..c008f11fa2a4 100644
> --- a/drivers/remoteproc/omap_remoteproc.h
> +++ b/drivers/remoteproc/omap_remoteproc.h
> @@ -42,6 +42,11 @@
>    * @RP_MBOX_SUSPEND_CANCEL: a cancel suspend response from a remote processor
>    * on a suspend request
>    *
> + * @RP_MBOX_SHUTDOWN: shutdown request for the remote processor
> + *
> + * @RP_MBOX_SHUTDOWN_ACK: successful response from remote processor for a
> + * shutdown request. The remote processor should be in WFI state short after.
> + *
>    * Introduce new message definitions if any here.
>    *
>    * @RP_MBOX_END_MSG: Indicates end of known/defined messages from remote core
> @@ -59,7 +64,9 @@ enum omap_rp_mbox_messages {
>   	RP_MBOX_SUSPEND_SYSTEM	= 0xFFFFFF11,
>   	RP_MBOX_SUSPEND_ACK	= 0xFFFFFF12,
>   	RP_MBOX_SUSPEND_CANCEL	= 0xFFFFFF13,
> -	RP_MBOX_END_MSG		= 0xFFFFFF14,
> +	RP_MBOX_SHUTDOWN	= 0xFFFFFF14,
> +	RP_MBOX_SHUTDOWN_ACK	= 0xFFFFFF15,
> +	RP_MBOX_END_MSG		= 0xFFFFFF16,
>   };
>   
>   #endif /* _OMAP_RPMSG_H */
> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> index a2ead87952c7..918a15e1dd9a 100644
> --- a/drivers/remoteproc/ti_k3_r5_remoteproc.c
> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> @@ -21,6 +21,7 @@
>   #include <linux/pm_runtime.h>
>   #include <linux/remoteproc.h>
>   #include <linux/suspend.h>
> +#include <linux/iopoll.h>
>   #include <linux/reset.h>
>   #include <linux/slab.h>
>   
> @@ -172,8 +173,23 @@ struct k3_r5_rproc {
>   	struct k3_r5_core *core;
>   	struct k3_r5_mem *rmem;
>   	int num_rmems;
> +	struct completion shutdown_complete;
>   };
>   
> +/*
> + * This will return true if the remote core is in Wait For Interrupt state.
> + */
> +static bool k3_r5_is_core_in_wfi(struct k3_r5_core *core)
> +{
> +	int ret;
> +	u64 boot_vec;
> +	u32 cfg, ctrl, stat;
> +
> +	ret = ti_sci_proc_get_status(core->tsp, &boot_vec, &cfg, &ctrl, &stat);
> +
> +	return !ret ? !!(stat & PROC_BOOT_STATUS_FLAG_R5_WFI) : false;

Too fancy for me :) Just return if (ret) right after get_status().

Looks like this function is called in a polling loop, if
ti_sci_proc_get_status() fails once, it won't get better,
no need to keep checking, we should just error out of
the polling loop.

Andrew

> +}
> +
>   /**
>    * k3_r5_rproc_mbox_callback() - inbound mailbox message handler
>    * @client: mailbox client pointer used for requesting the mailbox channel
> @@ -209,6 +225,10 @@ static void k3_r5_rproc_mbox_callback(struct mbox_client *client, void *data)
>   	case RP_MBOX_ECHO_REPLY:
>   		dev_info(dev, "received echo reply from %s\n", name);
>   		break;
> +	case RP_MBOX_SHUTDOWN_ACK:
> +		dev_dbg(dev, "received shutdown_ack from %s\n", name);
> +		complete(&kproc->shutdown_complete);
> +		break;
>   	default:
>   		/* silently handle all other valid messages */
>   		if (msg >= RP_MBOX_READY && msg < RP_MBOX_END_MSG)
> @@ -634,6 +654,7 @@ static int k3_r5_rproc_stop(struct rproc *rproc)
>   	struct k3_r5_cluster *cluster = kproc->cluster;
>   	struct device *dev = kproc->dev;
>   	struct k3_r5_core *core1, *core = kproc->core;
> +	bool wfi;
>   	int ret;
>   
>   
> @@ -650,6 +671,24 @@ static int k3_r5_rproc_stop(struct rproc *rproc)
>   		}
>   	}
>   
> +	/* Send SHUTDOWN message to remote proc */
> +	reinit_completion(&kproc->shutdown_complete);
> +	ret = mbox_send_message(kproc->mbox, (void *)RP_MBOX_SHUTDOWN);
> +	if (ret < 0) {
> +		dev_err(dev, "Sending SHUTDOWN message failed: %d. Halting core anyway.\n", ret);
> +	} else {
> +		ret = wait_for_completion_timeout(&kproc->shutdown_complete,
> +						  msecs_to_jiffies(1000));
> +		if (ret == 0) {
> +			dev_err(dev, "Timeout waiting SHUTDOWN_ACK message. Halting core anyway.\n");
> +		} else {
> +			ret = readx_poll_timeout(k3_r5_is_core_in_wfi, core,
> +						 wfi, wfi, 200, 2000);
> +			if (ret)
> +				dev_err(dev, "Timeout waiting for remote proc to be in WFI state. Halting core anyway.\n");
> +		}
> +	}
> +
>   	/* halt all applicable cores */
>   	if (cluster->mode == CLUSTER_MODE_LOCKSTEP) {
>   		list_for_each_entry(core, &cluster->cores, elem) {
> @@ -1410,6 +1449,7 @@ static int k3_r5_cluster_rproc_init(struct platform_device *pdev)
>   			goto err_config;
>   		}
>   
> +		init_completion(&kproc->shutdown_complete);
>   init_rmem:
>   		k3_r5_adjust_tcm_sizes(kproc);
>   
> 

  parent reply	other threads:[~2024-06-28 22:51 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-06-21 15:00 [PATCH 0/4] remoteproc: k3-r5: Introduce suspend to ram support Richard Genoud
2024-06-21 15:00 ` [PATCH 1/4] remoteproc: k3-r5: Fix IPC-only mode detection Richard Genoud
2024-06-28 19:53   ` Mathieu Poirier
2024-06-28 19:58     ` Mathieu Poirier
2024-07-01  9:13       ` Hari Nagalla
2024-07-01 16:38         ` Mathieu Poirier
2024-06-21 15:00 ` [PATCH 2/4] remoteproc: k3-r5: Introduce PM suspend/resume handlers Richard Genoud
2024-06-28 20:48   ` Mathieu Poirier
2024-07-01  7:30     ` Richard GENOUD
2024-07-01 19:02   ` kernel test robot
2024-06-21 15:00 ` [PATCH 3/4] remoteproc: k3-r5: k3_r5_rproc_stop: code reorder Richard Genoud
2024-06-28 21:18   ` Mathieu Poirier
2024-07-01  8:03     ` Richard GENOUD
2024-07-01 16:35       ` Mathieu Poirier
2024-07-01 16:49         ` Richard GENOUD
2024-06-21 15:00 ` [PATCH 4/4] remoteproc: k3-r5: support for graceful stop of remote cores Richard Genoud
2024-06-28 21:20   ` Mathieu Poirier
2024-07-01 16:38     ` Richard GENOUD
2024-06-28 22:50   ` Andrew Davis [this message]
2024-07-01 16:48     ` Richard GENOUD
2024-07-01 21:55   ` kernel test robot
2024-06-28 21:23 ` [PATCH 0/4] remoteproc: k3-r5: Introduce suspend to ram support Mathieu Poirier
2024-07-01  9:59 ` Hari Nagalla
2024-07-08  7:33   ` Richard GENOUD

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