From: Florian Fainelli <f.fainelli@gmail•com>
To: Peng Fan <peng.fan@nxp•com>,
"robh+dt@kernel•org" <robh+dt@kernel•org>,
"mark.rutland@arm•com" <mark.rutland@arm•com>,
"jassisinghbrar@gmail•com" <jassisinghbrar@gmail•com>,
"sudeep.holla@arm•com" <sudeep.holla@arm•com>,
"andre.przywara@arm•com" <andre.przywara@arm•com>
Cc: "devicetree@vger•kernel.org" <devicetree@vger•kernel.org>,
"linux-kernel@vger•kernel.org" <linux-kernel@vger•kernel.org>,
"linux-arm-kernel@lists•infradead.org"
<linux-arm-kernel@lists•infradead.org>,
dl-linux-imx <linux-imx@nxp•com>
Subject: Re: [PATCH V8 2/2] mailbox: introduce ARM SMC based mailbox
Date: Mon, 23 Sep 2019 19:48:27 -0700 [thread overview]
Message-ID: <1f01ea8e-8953-82ae-933c-721385dc0c13@gmail.com> (raw)
In-Reply-To: <1569287538-10854-3-git-send-email-peng.fan@nxp.com>
Hi Peng,
On 9/23/2019 6:14 PM, Peng Fan wrote:
> From: Peng Fan <peng.fan@nxp•com>
>
> This mailbox driver implements a mailbox which signals transmitted data
> via an ARM smc (secure monitor call) instruction. The mailbox receiver
> is implemented in firmware and can synchronously return data when it
> returns execution to the non-secure world again.
> An asynchronous receive path is not implemented.
> This allows the usage of a mailbox to trigger firmware actions on SoCs
> which either don't have a separate management processor or on which such
> a core is not available. A user of this mailbox could be the SCP
> interface.
>
> Modified from Andre Przywara's v2 patch
> https://lore.kernel.org/patchwork/patch/812999/
>
> Cc: Andre Przywara <andre.przywara@arm•com>
> Signed-off-by: Peng Fan <peng.fan@nxp•com>
> ---
[snip]
> +typedef unsigned long (smc_mbox_fn)(unsigned int, unsigned long,
> + unsigned long, unsigned long,
> + unsigned long, unsigned long,
> + unsigned long);
> +static smc_mbox_fn *invoke_smc_mbox_fn;
Sorry for spotting this so late, the only thing that concerns me here
with this singleton is if we happen to have both an arm,smc-mbox and
arm,hvc-mbox configured in the system, this would not work. I do not
believe this could be a functional use case, but we should probably
guard against that or better yet, move that into the arm_smc_chan_data
private structure?
--
Florian
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next prev parent reply other threads:[~2019-09-24 2:48 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-24 1:14 [PATCH V8 0/2] mailbox: arm: introduce smc triggered mailbox Peng Fan
2019-09-24 1:14 ` [PATCH V8 1/2] dt-bindings: mailbox: add binding doc for the ARM SMC/HVC mailbox Peng Fan
2019-09-24 3:00 ` Florian Fainelli
2019-09-24 1:14 ` [PATCH V8 2/2] mailbox: introduce ARM SMC based mailbox Peng Fan
2019-09-24 2:48 ` Florian Fainelli [this message]
2019-09-24 2:54 ` Peng Fan
2019-09-24 3:20 ` kbuild test robot
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