linux-kernel - Re: [PATCH v3 8/9] mailbox: mediatek: Add CMDQ secure mailbox driver

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Date: Wed, 3 Jan 2024 07:14:54 +0000
From: Jason-JH Lin (林睿祥) <Jason-JH.Lin@...iatek.com>
To: CK Hu (胡俊光) <ck.hu@...iatek.com>,
	"jassisinghbrar@...il.com" <jassisinghbrar@...il.com>,
	"matthias.bgg@...il.com" <matthias.bgg@...il.com>,
	"angelogioacchino.delregno@...labora.com"
	<angelogioacchino.delregno@...labora.com>, "robh+dt@...nel.org"
	<robh+dt@...nel.org>, "krzysztof.kozlowski+dt@...aro.org"
	<krzysztof.kozlowski+dt@...aro.org>, "chunkuang.hu@...nel.org"
	<chunkuang.hu@...nel.org>
CC: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-mediatek@...ts.infradead.org" <linux-mediatek@...ts.infradead.org>,
	Singo Chang (張興國) <Singo.Chang@...iatek.com>,
	Johnson Wang (王聖鑫) <Johnson.Wang@...iatek.com>,
	"linux-media@...r.kernel.org" <linux-media@...r.kernel.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	Jason-ch Chen (陳建豪)
	<Jason-ch.Chen@...iatek.com>, Shawn Sung (宋孝謙)
	<Shawn.Sung@...iatek.com>, "mchehab@...nel.org" <mchehab@...nel.org>,
	Nancy Lin (林欣螢) <Nancy.Lin@...iatek.com>,
	"conor+dt@...nel.org" <conor+dt@...nel.org>,
	Project_Global_Chrome_Upstream_Group
	<Project_Global_Chrome_Upstream_Group@...iatek.com>,
	"linux-arm-kernel@...ts.infradead.org" <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v3 8/9] mailbox: mediatek: Add CMDQ secure mailbox driver

On Fri, 2023-12-29 at 01:27 +0000, CK Hu (胡俊光) wrote:
> Hi, Jason:
> 
> On Fri, 2023-12-22 at 12:52 +0800, Jason-JH.Lin wrote:
> > To support secure video path feature, GCE have to read/write
> > registgers
> > in the secure world. GCE will enable the secure access permission
> > to
> > the
> > HW who wants to access the secure content buffer.
> > 
> > Add CMDQ secure mailbox driver to make CMDQ client user is able to
> > sending their HW settings to the secure world. So that GCE can
> > execute
> > all instructions to configure HW in the secure world.
> > 
> > Signed-off-by: Jason-JH.Lin <jason-jh.lin@...iatek.com>
> > ---
> 
> [snip]
> 
> > +
> > +static int cmdq_sec_session_send(struct cmdq_sec_context *context,
> > +				 struct cmdq_sec_task *sec_task, const
> > u32 iwc_cmd,
> > +				 const u32 thrd_idx, struct cmdq_sec
> > *cmdq)
> > +{
> > +	int err = 0;
> > +	u64 cost;
> > +	struct iwc_cmdq_message_t *iwc_msg = NULL;
> > +
> > +	iwc_msg = (struct iwc_cmdq_message_t *)context->iwc_msg;
> > +
> > +	memset(iwc_msg, 0, sizeof(*iwc_msg));
> > +	iwc_msg->cmd = iwc_cmd;
> > +	iwc_msg->cmdq_id = cmdq->pdata->hwid;
> > +	iwc_msg->command.thread = thrd_idx;
> > +
> > +	switch (iwc_cmd) {
> > +	case CMD_CMDQ_IWC_SUBMIT_TASK:
> > +		err = cmdq_sec_fill_iwc_msg(context, sec_task,
> > thrd_idx);
> > +		if (err)
> > +			return err;
> > +		break;
> > +	case CMD_CMDQ_IWC_CANCEL_TASK:
> > +		iwc_msg->cancel_task.wait_cookie = sec_task-
> > > wait_cookie;
> > 
> > +		iwc_msg->cancel_task.thread = thrd_idx;
> > +		break;
> > +	case CMD_CMDQ_IWC_PATH_RES_ALLOCATE:
> > +		if (!cmdq->shared_mem || !cmdq->shared_mem->va) {
> > +			dev_err(cmdq->mbox.dev, "%s %d: shared_mem is
> > NULL", __func__, __LINE__);
> > +			return -EFAULT;
> > +		}
> > +		iwc_msg->path_resource.size = cmdq->shared_mem->size;
> > +		iwc_msg->path_resource.share_memoy_pa = cmdq-
> > > shared_mem->pa;
> > 
> > +		iwc_msg->path_resource.use_normal_irq = 1;
> > +		break;
> > +	default:
> > +		break;
> > +	}
> > +
> > +	cmdq->sec_invoke = sched_clock();
> > +	dev_dbg(cmdq->mbox.dev, "%s execute cmdq:%p sec_task:%p
> > command:%u thread:%u cookie:%d",
> > +		__func__, cmdq, sec_task, iwc_cmd, thrd_idx,
> > +		sec_task ? sec_task->wait_cookie : -1);
> > +
> > +	/* send message */
> > +	err = cmdq_sec_execute_session(&context->tee_ctx, iwc_cmd,
> > CMDQ_TIMEOUT_DEFAULT);
> > +
> > +	cmdq->sec_done = sched_clock();
> > +	cost = div_u64(cmdq->sec_done - cmdq->sec_invoke, 1000000);
> > +	if (cost >= CMDQ_TIMEOUT_DEFAULT)
> 
> Maybe for some client driver, 1 ms is too long, and for some client
> driver 1 second is not long. So I think the timeout detection should
> be
> done by client driver. And the execution time depend on the command
> buffer generated by client driver, so only client driver has the
> ability to debug the command buffer it generated. So it's not
> necessary
> to detect timeout in cmdq driver.
> 
> Regards,
> CK
> 

OK, I'll remove this timeout detection in cmdq driver.

Regards,
Jason-JH.Lin

> > +		dev_err(cmdq->mbox.dev, "%s execute timeout cmdq:%p
> > sec_task:%p cost:%lluus",
> > +			__func__, cmdq, sec_task, cost);
> > +	else
> > +		dev_dbg(cmdq->mbox.dev, "%s execute done cmdq:%p
> > sec_task:%p cost:%lluus",
> > +			__func__, cmdq, sec_task, cost);
> > +
> > +	if (err)
> > +		return err;
> > +
> > +	context->state = IWC_SES_ON_TRANSACTED;
> > +	return 0;
> > +}
> > +