Re: [PATCH v2 16/17] drivers/firmware/sdei: Retrieve event signaled property on registration

From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Gavin Shan <gshan@redhat.com>
Cc: mark.rutland@arm.com, catalin.marinas@arm.com,
	james.morse@arm.com, shan.gavin@gmail.com, will@kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 16/17] drivers/firmware/sdei: Retrieve event signaled property on registration
Date: Mon, 27 Jul 2020 10:04:14 +0100	[thread overview]
Message-ID: <20200727100414.00000ee2@Huawei.com> (raw)
In-Reply-To: <f48a7bc6-836f-f570-b6a3-21423649b1ac@redhat.com>

On Mon, 27 Jul 2020 10:53:27 +1000
Gavin Shan <gshan@redhat.com> wrote:

> Hi Jonathan,
> 
> On 7/24/20 1:24 AM, Jonathan Cameron wrote:
> > On Wed, 22 Jul 2020 19:57:39 +1000
> > Gavin Shan <gshan@redhat.com> wrote:
> >   
> >> This retrieves the event signaled property when it's created for the
> >> first time. The property will be needed when SDEI virtualization is
> >> supported.
> >>
> >> Signed-off-by: Gavin Shan <gshan@redhat.com>  
> > 
> > These last two patches are probably fine but hard to tell without a user.
> >   
> 
> Good question. Let me explain the background and please let me know
> if you have more questions. SDEI was suggested by Marc to deliver
> the notification during the asynchronous page fault, so that the
> process can be rescheduled in guest. Unfortunately, we don't have
> SDEI (or virtualized SDEI) supported yet. So the additional event
> information is needed when SDEI virtualization is supported.
> 
> The code of SDEI virtualization can be checked out from github:
> 
> https://github.com/gwshan/linux/tree/sdei (branch: "sdei")
Thanks.

I'd be tempted to move these two patches to the next series
that includes the users.

I forgot to say, I'm fine with all the patches I didn't comment on.

Jonathan

> 
>   
> >> ---
> >>   drivers/firmware/arm_sdei.c | 6 ++++++
> >>   include/linux/arm_sdei.h    | 1 +
> >>   2 files changed, 7 insertions(+)
> >>
> >> diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c
> >> index cf10fec57f2a..7518d3febf53 100644
> >> --- a/drivers/firmware/arm_sdei.c
> >> +++ b/drivers/firmware/arm_sdei.c
> >> @@ -204,6 +204,12 @@ static struct sdei_event *sdei_event_create(u32 event_num,
> >>   		goto fail;
> >>   	event->type = result;
> >>   
> >> +	err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_SIGNALED,
> >> +				      &result);
> >> +	if (err)
> >> +		goto fail;
> >> +	event->signaled = result;
> >> +
> >>   	if (event->type == SDEI_EVENT_TYPE_SHARED) {
> >>   		reg = kzalloc(sizeof(*reg), GFP_KERNEL);
> >>   		if (!reg) {
> >> diff --git a/include/linux/arm_sdei.h b/include/linux/arm_sdei.h
> >> index 11af6410dd52..7f3ed7e4b680 100644
> >> --- a/include/linux/arm_sdei.h
> >> +++ b/include/linux/arm_sdei.h
> >> @@ -51,6 +51,7 @@ struct sdei_event {
> >>   	u32			event_num;
> >>   	u8			type;
> >>   	u8			priority;
> >> +	u8			signaled;
> >>   
> >>   	/* This pointer is handed to firmware as the event argument. */
> >>   	union {  
> 
> Thanks,
> Gavin
> 

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