From: Jens Wiklander <jens.wiklander@linaro.org>
To: Julien Grall <julien@xen.org>
Cc: xen-devel@lists.xenproject.org, patches@linaro.org,
Volodymyr Babchuk <volodymyr_babchuk@epam.com>,
Stefano Stabellini <sstabellini@kernel.org>,
Bertrand Marquis <bertrand.marquis@arm.com>,
Michal Orzel <michal.orzel@amd.com>
Subject: Re: [XEN PATCH v4 5/5] xen/arm: ffa: support notification
Date: Tue, 7 May 2024 13:17:16 +0200 [thread overview]
Message-ID: <CAHUa44Fc6pRDjUr1HiW7r=QB4kxCEdRz_G9ATLqEg2KqNp+gFA@mail.gmail.com> (raw)
In-Reply-To: <447340c3-d57a-411b-8d4d-29e8683b27d9@xen.org>
Hi Julien,
On Fri, May 3, 2024 at 4:25 PM Julien Grall <julien@xen.org> wrote:
>
> Hi Jens,
>
> On 03/05/2024 14:54, Jens Wiklander wrote:
> >>> +static int ffa_setup_irq_callback(struct notifier_block *nfb,
> >>> + unsigned long action, void *hcpu)
> >>> +{
> >>> + unsigned int cpu = (unsigned long)hcpu;
> >>> + struct notif_irq_info irq_info = { };
> >>> +
> >>> + switch ( action )
> >>> + {
> >>> + case CPU_ONLINE:
> >>
> >> Can't you execute the notifier in CPU_STARTING? This will be called on
> >> the CPU directly, so you should be able to use request_irq(...).
> >
> > I tried that first but it failed with the ASSERT_ALLOC_CONTEXT() in _xmalloc().
> >
> > I've also tested a three-step solution with CPU_UP_PREPARE,
> > CPU_STARTING, and CPU_UP_CANCELED.
> > My approach here is more direct, but it still suffers from a weakness
> > in error handling even if it seems quite unlikely to run out of heap
> > or for setup_irq() to fail at this stage.
>
> Ah I didn't notice that notify_cpu_starting() is called with IRQ
> disabled. I assumed they would be enabled.
>
> Then I would consider to do:
>
> diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
> index 6efed876782e..db322672e508 100644
> --- a/xen/arch/arm/smpboot.c
> +++ b/xen/arch/arm/smpboot.c
> @@ -389,6 +389,7 @@ void asmlinkage start_secondary(void)
> */
> init_maintenance_interrupt();
> init_timer_interrupt();
> + init_tee_interrupt();
>
> local_abort_enable();
>
> And plumb through the TEE subsystem.
I'll use that in the next version, it should remove a lot of complex code.
Thanks,
Jens
prev parent reply other threads:[~2024-05-07 11:17 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-02 14:56 [XEN PATCH v4 0/5] FF-A notifications Jens Wiklander
2024-05-02 14:56 ` [XEN PATCH v4 1/5] xen/arm: ffa: refactor ffa_handle_call() Jens Wiklander
2024-05-02 14:56 ` [XEN PATCH v4 2/5] xen/arm: ffa: use ACCESS_ONCE() Jens Wiklander
2024-05-02 14:56 ` [XEN PATCH v4 3/5] xen/arm: ffa: simplify ffa_handle_mem_share() Jens Wiklander
2024-05-02 14:56 ` [XEN PATCH v4 4/5] xen/arm: allow dynamically assigned SGI handlers Jens Wiklander
2024-05-02 14:56 ` [XEN PATCH v4 5/5] xen/arm: ffa: support notification Jens Wiklander
2024-05-03 9:59 ` Julien Grall
2024-05-03 13:54 ` Jens Wiklander
2024-05-03 14:25 ` Julien Grall
2024-05-07 11:17 ` Jens Wiklander [this message]
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